hiroshima, nagasaki, chernobyl & fukushima: a...
TRANSCRIPT
Hiroshima, Nagasaki, Chernobyl & Fukushima: A Medical Radiologist's
Advice on Radiation Exposure, Cancer Risks, and Other Threats to
Public Health
by Keiichi Nakagawa, MD, Ph.D
( 放射線医が語る被ばくと発がんの真実・中川恵一 )
translated by Alexander Isao Holmes
32
Valuable Records, a Legacy to Posterity Decisive Factors in Radiation Dose The Health Status of Atom Bomb Survivors Overview of the Atomic Bomb Damage(2) Another Chapter in the True Story of the Atom-Bombed Cities The Health Status of Post-Blast Radioactivity Survivors
Chapter 4 The Truth About the Chernobyl Nuclear Accident The Worst Nuclear Accident in History The Actual Number of Victims The Increase in Thyroid Cancer in Children Was There a Sudden Increase in Bladder Cancer? The Reason Thyroid Cancer in Children Could Not Be Prevented The Complete Food Chain Leading to Cancer Why Iodine Collects in the Thyroid Gland Thyroid Cancer’s Real Danger to Children Radioactive Iodine Is Also Sometimes Used to Treat Cancer The Differences Between Chernobyl and Fukushima Restrictions on Food Products Came Too Late in Chernoby Japanese Food Regulations Are Safe Problems With Defining the Evacuation Zone in Fukushima Average Life Expectancy Fell After Chernobyl What Unnecessary Evacuation Really Does Taking the Lessons of Chernobyl to Heart
Conclusion
Chapter 5 Radiation’s International Standards(1) International Organizations Active on Radiation Exposure-Related Problems International Rules Regarding Exposures United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) The International Commission on Radiological Protection (ICRP)
Introduction
Chapter 1 The Truth About Radiation(1) The True Nature and Risks of Radioactive Substances Strontium Has Been Detected in Yokohama The Threat of Radiation(2) The Truth About Internal Exposure What Is “Internal Exposure”? But What, Then, Exactly Is “Internal Exposure to Radiation”? The Dangers of Internal Exposure Radioactive Material in Food The Truth About Exposure to Cesium
Chapter 2 Cancer Risk Facts(1) What Causes Cancer? Japan, World Cancer Record Holder Why Do People Get Cancer? The Longer the Average Life Expectancy, the Higher the Cancer Rates Our Growing Population of “Youthful” Seniors Your Chances of Getting Cancer Are 50-50 Magic Bullets For Cancer? (Only Lifestyle Improvement and Early Detection Work) Total Cancer Rates Would Be Cut by 20% if Nobody Smoked The Younger the Smoker Is, the Greater Tobacco’s Effect on the Human Body Alcohol + Tobacco = Double the Rate of Cancer Drinking Can Give You Cancer! (2) How to Prevent Cancer The Seven Pillars of Cancer Prevention Early Detection: Finding the Disease Before Symptoms Appear Comparing Exposure to Radiation vs Lifestyle Choices
Chapter 3 The Truth About Hiroshima and Nagasaki(1) What the Data From Hiroshima and Nagasaki Tell Us
5
88811252525262627
29292930313233333335353638383839
4343
Table of Contents434344444848
5151515253535455555657585959606163
65
7373737374
54
The Most Reliable Framework Based on International AgreementsEuropean Committee on Radiation Risk (ECRR)(2) International Rules to Protect People From Exposure to Radiation The Normal Standard: 1 mSv Annual Exposure Overreactions Have Harmful Side Effects ICRP’s Message Regarding Fukushima The Dilemmas Confronting Us
Chapter 6 Fukushima Now and in the FutureFukushima’s Current Situation (2011) The Problems Are Piling Up Future Risks From Radioactive Substances The Ill-Timed Order to Evacuate to Iitate-Mura The Truth About External Exposures External Exposures in Fukushima Internal Exposure in Fukushima (2) My Visits to Iitate-mura My Visits to Iitate-mura and What I Saw Intensive-Care Nursing Homes: Evacuate or Stay Put? Residents Speak for Themselves Verification of Official Published Data Keys to Decontamination High Exposure Risks for Accident Site Workers Cancer Rates in Fukushima Will Not Increase Balancing Risks While Making Urgent Decisions
Chapter 7 Responses to Radiation Exposure in Times of Emergency
Chapter 8 Addressing Anxieties About Radiation Exposure and Cancer
In Conclusion
75757676777882
8484848485868787888889909192939394
96
103
112
Ten months have passed since the Great East Japan Earthquake and tsunami
of March 11, 2011, and the ensuing nuclear accidents. As we begin to move
towards reconstruction, the problem of exposure to radiation has become a
major hurdle to recovery.
Since late April, beginning about one month after the accident, I have been
periodically visiting Iitate-mura in Fukushima Prefecture together with a team
from the Tokyo University Hospital Department of Radiology. We listened
directly to what residents had to say and we have been providing advice and
recommendations on a variety of health-related issues to authorities.
My strongest impression at these meetings in the affected area was a sense of
people’s vague but intense anxiety. People had many questions: What exactly
is going on in the current situation? How much radiation is there, and what
kind of effect does this have on one’s health? What about the safety of our
food and water? Should we relocate? And what kind of care do the children
need? What is going to happen next?
In addition to questions, we heard rumors that somewhere in Japan a show
using fireworks made in Fukushima had been cancelled, that pinewood from
trees in the disaster-stricken areas would not be allowed to be burned in
religious rituals, and things like that. I also heard that school children from the
areas affected by the disaster were victims of unjustifiable discrimination in
the schools they had been transferred to.
We cannot simply shrug off these behaviors as symptoms of a lack of morals
in the Japanese. The main problem here is the lack of accurate information.
Ever since the accident at the Fukushima nuclear power plant, newspaper
and magazine articles, TV shows, and the Internet have been deluging us
with factoids and statements that ignite and fuel fears. People who are not
experts are making irresponsible statements all the time, and it is fair to say
that these statements have awakened the public’s anxieties and prejudices
and distorted their understanding of radiation.
“Escape westward!” “You shouldn’t eat vegetables from Fukushima!” “There
will be more cancer, more birth defects, strange new diseases, and increasing
mental retardation in Japan 20 years from now...” I heard of a family who
quit their jobs and relocated to another area. Another person, they said, only
Introduction
76
eats imported food products. One mother (probably just one of many...) will
not allow her children to play outside at all, because she wants to protect
them from radiation. These actions were probably deemed best by parents
who had to make painful choices to protect the health of their families, small
children in particular.
However, as I stated above, the most serious issue is the lack of accurate
information. The Fukushima nuclear accident has been repeatedly compared
to the Chernobyl nuclear accident. People say, for instance, “It is the same
level 7 as Chernobyl,” “There have been hot spots identified in the center
of Tokyo that are on a par with Chernobyl levels,” “Restrictions on food are
stricter than for Chernobyl,” and “Compared to the forced relocation area in
Chernobyl, the standards are laxer in Fukushima,” and so on.
On the other hand, I wonder just how well the public knows the facts
below. In 2011, 25 years after the Chernobyl nuclear accident (April 1986),
the Russian Government published an enormous 150-page comprehensive
report titled “25 Years After the Chernobyl Accident: Summary and Overview
of its Impact and Overcoming its Aftereffects, 1986-2011.” In its Conclusions,
there is one sentence that I think we should pay very close attention to:
Analysis of the situation 25 years after the Chernobyl accident reveals that,
compared to the radioactivity released, other factors, namely the economic
and social impacts of the accident, caused much more serious damage:
psychological stress, disruption of familiar lifestyles, limitations on economic
activities, and material losses.
Amidst the welter of confusing factoids flying around, I am very concerned
that the same mistakes could be made in Japan. The danger is that other,
more serious, harm may result from actions based on fears and anxieties
based on misinformation. Even non-experts are boldly professing their views
on the “menace” of radiation. I wonder if those people have ever considered
the possibility that what they are saying does more harm than good.
All this misinformation makes me almost angry, but at the same time, as a
clinician who specializes in radiation therapy, I realize that at this precise
moment I have a special role to fulfill.
At the root of it all is the nuclear accident. Of course we must bring
responsibility to bear on the people in charge at Tokyo Electric Power
Company (TEPCO) and at the Fukushima nuclear power plant who let this
immense problem happen. I also believe that residents should be fully
compensated for their losses. However, unfortunately, we will have to deal
for a long time to come with the problems of radiation released from the
Fukushima nuclear power plant. I doubt that anybody ever imagined we
would live in a world like Japan today, where people go out and buy their
own dosimeters to measure radiation levels in the parks that they grew up
playing in and in the streets of the towns that they live in.
We must do something to prevent factoids and malicious rumors from doing
more harm. And in order to relieve the anxiety that people are feeling, not
only in the areas affected by the disaster but all over Japan, what is most
needed now is accurate information about radiation.
I have treated cancer patients as a radiologist for 27 years at the Department
of Radiology of the University of Tokyo Hospital. I believe that the anxiety
inspired by radiation comes from fears that cancer risks will rise. Using my
many years of experience as a radiologist, I would like to explain to readers
the relationship between exposure to radiation and how cancer forms, in
detail but in a way that is as easy to understand as possible. Japan is the
only nation that has suffered atomic bombings, and has the world’s highest
cancer rates. It is tragic that atomic bombs were dropped on Hiroshima and
Nagasaki and that so many people lost their lives there. In this book, I hope
to communicate a correct understanding of how radiation affects the human
body; I will cite information gained in the 60-plus years since the atomic
bombing of Japan as well as the comprehensive Russian study published to
mark the 25th anniversary of the Chernobyl nuclear accident.
I believe that this information will limit the damage done by rumors and
misinformation, and that actions based on accurate information are what is
needed so that, as soon as possible, each and every one of us can go back to
living with a sense of security.
I sincerely hope that this book will help readers to become secure in their
knowledge of radiation’s real effects.
98
(1) The True Nature and Risks of Radioactive Substances
Strontium Has Been Detected in Yokohama
Since the nuclear accident at the Fukushima Daiichi nuclear power plant
on March 11, 2011, not a single day has gone by without television and
newspaper reports about radiation. The names of radioactive substances
such as iodine and cesium, once rarely mentioned outside of academia, now
seem like they are part of our everyday lives. (I will explain more about iodine
and cesium in greater depth later.) Plutonium and strontium have also been
released from nuclear reactors.
In October of 2011, strontium was detected on the rooftop of an apartment
complex in Yokohama, 250 kilometers away from the nuclear power plant.
This was taken up by newspapers, television, and other media. Presumably
many people felt that some very scary substances were headed their way.
Strontium: a Substance Stored in the Bones That Causes Leukemia
Exactly what kind of substance is strontium? Chemically, strontium has
properties similar to calcium and, once inside the human body, is stored in
bone tissues. If the amount taken in is large, the risk of leukemia and of bone
cancer increases; it is thought to especially affect children, whose bones are
still in the process of formation and therefore more susceptible to this risk.
Since strontium is assumed to be less likely to be scattered and spread by
the wind, many specialists do not believe that this strontium was blown from
Fukushima to a location as far away as Yokohama.
Strontium is thought to enter the human body via the food we eat, since it is
stored mainly in the bones and internal organs of fish, and once it is absorbed
into human bones, it is said to take from three to seven years to be eliminated
from the body.
Is Yokohama Eligible to Become an “Evacuation Zone”?
The strontium found in Yokohama is called strontium-90 and has a half life
of thirty years. The amount of radiation is 195 becquerels per kilogram. (The
becquerel is a unit of radioactivity.) This is significantly higher than the 77
becquerels found in Fukushima city’s soil between April and May.
Currently, cesium is the radioactive substance most likely to pose a problem,
and wherever cesium is detected, small amounts of strontium are also being
detected. The amounts are very small, and I think it is safe to say that this
strontium has no effect on the human body.
However, there is more to the story of this strontium found in Yokohama. As
a result of a detailed analysis of sediments collected by the city of Yokohama,
the Ministry of Education, Culture, Sports, Science and Technology
announced that neither of the substances found there were newly deposited
due to the accident at the Fukushima Daiichi Nuclear Power Plant. So where
did they come from?
Strontium Was Already Present in the Environment
This strontium has actually been present in the environment for a long time.
In the 1960s, the United States and other Western nations, Russia (formerly
the USSR), and China, as well as other nations were vying with each other
to test nuclear weapons -- in the atmosphere. As a result, large amounts of
plutonium and strontium were released and have spread all over the earth.
The plutonium spewed into the stratosphere because of this testing spree
has gradually fallen to the ground. The amounts 50 years ago were 5000
times the current amount, which is enormous when compared to the amount
released due to the accident in Fukushima. Nuclear weapons testing in this
way is simply unforgivable.
The Ministry of Education, Culture, Sports, Science and Technology has
adopted the position that this strontium recently detected in Yokohama is
probably fallout: a residue of nuclear weapons testing in the environment
whose byproducts later descended to the ground.
If this is true, this problem is not limited to the city of Yokohama. In the wake
of the accident in Fukushima, the presence of radioactive substances in
familiar places was brought rudely to our attention for the first time. It is not
widely known, but the Ministry of Education, Culture, Sports, Science and
Technology has been publishing data regarding these radioactive substances
detected in Japan since before the Fukushima accident occurred.
Highly Toxic Plutonium
Plutonium is used to make nuclear weapons. Its high radioactivity and toxicity
Chapter 1The Truth About Radiation
1110
give it word associations with the Devil. Once inside the human body, it
accumulates in the lungs. Plutonium is also known to have an extremely long
half life. I will explain in greater detail later what a “half life” is, but the main
problems are plutonium isotopes 238 to 244. The physical half life, a time
period that cuts their radioactivity in half, is 87.7 years for 238, 24,100 years
for 239, and 6570 years for 240. These are very, very long periods of time.
Plutonium was used in the atom bomb dropped on Nagasaki. The bomb that
exploded in the sky above Nagasaki released enormous heat and radiation,
snuffing out thousands of precious lives in a flash.
Photographs of the bomb victims shows “keloid” (fibrous) scars on their skin.
This symptom may be what leaves the most vivid and cruel impression of
atom bomb radiation in people’s hearts. Yet however much these keloid scars
look like the result of intense radiation, this is not in fact the case. I will write
about this in greater detail in Chapter 3, but for the majority of atom bomb
victims who lost their lives, what killed them was not radiation, but their
severe burns. That this fact is so little known illustrates how poorly people,
even in Japan -- the only country in the world that has been the victim of
nuclear bombings -- understand the reality of the damage done by nuclear
bombs or what kind of effects radiation has on the human body.
Current Levels of Plutonium Pose Only a Small Risk
Plutonium was also released in the course of the nuclear accident at
Fukushima, and like strontium, plutonium is thought not to scatter easily.
However, according to a study of the soil conducted by the Ministry of
Education, Culture, Sports, Science and Technology in 100 locations within
80 kilometers of the power plant between June and July 2011, plutonium
238 (a substance which is thought to be related to this accident) was found
in six locations in Fukushima Prefecture (including Iitate-mura, Soma-cho and
Namie-machi, which I visited; more on that later).
The radiation readings 45 km away from the nuclear power plant in Iitate-
mura are 0.82 becquerels (per square meter), 4 becquerels in Namie-machi,
and 0.57 becquerels in Futaba-machi. Similarly in Minami-Soma-shi, a total of
15 becquerels of plutonium 239 and 240 was detected.
Because plutonium was also found in Yokohama, I am unsure whether we
can be certain that this plutonium is really from the nuclear reactor and not
from past atmospheric nuclear weapons tests.
However, compared to cesium, which is considered the biggest problem
right now, it certainly doesn’t scatter long distances as easily, and I think it’s
safe to say that, in these amounts, it won’t present health hazards.
The Threat of Radiation
Now let me explain a little about the effects that radiation has on the human
body. I am not trying to scare anybody by saying this, but if a person is
instantaneously exposed all over the body to very, very large amounts of
radiation, that person will die. Out of a given number of people who have
their whole body exposed to 4,000 millisieverts (mSv) of radiation, half will
die.
Of course, this kind of exposure to large amounts of a radioactive substance
is exceptional to say the least, but in 1999 this did occur in the Tokaimura
nuclear accident (called the “JCO rinkai-jiko” (criticality accident) in Japanese)
in Ibaraki Prefecture, Japan. The two people who died due to full-body
exposure are thought to have been exposed to between 8,000 and 18,000
mSv.
A criticality occurs when nuclear substances (uranium in the case of JCO)
undergo a fission chain reaction. This is not a problem when it happens in a
confined environment such as inside a reactor, but in the JCO case there was
an “uncovered” criticality in a corner of the plant. Inside the bodies of those
exposed, the stem cells (which produce blood cells and intestinal mucosa)
underwent “apoptosis” (programmed cell death) induced by large amounts
of radiation, resulting in a decrease in the number of blood cells, severe
diarrhea, and bloody stool.
This is the same mechanism that causes side effects in people who undergo
anti-cancer chemotherapy and radiation therapy. Cells throughout the
victims’ body stopped reproducing, and this killed them.
On the other hand, while there are no external symptoms for whole-body
exposures of less than 1000 mSv, tests show there is a noticeable decrease in
white blood cells at levels greater than 250 mSv. For workers on-site where
the nuclear accident took place, the exposure limit has been raised from 100
13
mSv to 250 mSv; this means that the limit was brought up to the borderline
level for which tests show no abnormalities.
How to Interpret the Much-Debated “Exposures Under 100 mSv”
So is it that exposure to less than 250 mSv, a level at which no outward
symptoms or test abnormalities are seen, is not a problem?
No, one cannot say it is not a problem, because there is an effect: once
exposure exceeds a certain amount, the risk of cancer in the future increases.
The risk that someone will get cancer later in life becomes higher. One can
say, however, that no health hazards other than cancer are involved.
So for an ordinary citizen, the problem with exposure is the problem of
getting cancer later. This is the biggest reason why I, being a clinician
involved in cancer treatment, can speak about the nuclear accident at the
Fukushima Daiichi power plant.
The real issue in this discussion is whether exposures of less than 100 mSv
should be seen as dangerous or not. I say that exposure of less than 100 mSv
presents a very, very low risk of causing cancer. The data from Hiroshima and
Nagasaki provide evidence corroborating my view. The data from studies
conducted over long periods of time on victims at Hiroshima and Nagasaki
do not give any evidence that the risk of cancer is increased by exposures
below 100 mSv.
Not everyone agrees with me, however: even among experts, there are
sharply contrasting views on exposures below 100 mSv. International experts
whose job is to protect the public from radiation have adopted the premise
that radiation levels lower than 100 mSv do have health effects.
They support what is called the “linear no-threshold hypothesis” or model,
which assumes that cancer risk increases proportionately in response
to exposures rising from zero to 100 mSv. In the graph at the end of this
section, a dotted line slopes down leftward from 100 mSv all the way to
zero to signify the chance that cancer risk will increase from the baseline
value even when exposure is less than 100 mSv. This is taking a more safety-
conscious approach than other experts do. However, this assumption is not
a scientifically based hypothesis: it is merely a policy aiming to decrease
exposure as much as possible.
1514
There is no scientific proof that exposure to less than 100 mSv of radiation
increases cancer risk. Scientific data are, however, available on the risk of
exposures over 100 mSv. Below that threshold, there are no data; even if
there is a risk, therefore, it’s so small that it can’t be measured.
Think of it this way: there is no scientific proof that cancer risks do not
increase as a result of the sugar and butter we consume at the dinner table.
On the other hand, if we consumed kilos of sugar and butter daily, it is almost
certain that the risk of cancer would go up. However, just because there’s no
scientific evidence regarding moderate amounts of exposure, can one
conclude that the risk of cancer from moderate amounts will increase just
because exposure to large amounts increases risks?
I think it is permissible to say that the risks are extremely small, although
one might also say that the risks appear small simply because scientific data
are unobtainable. The problem with the linear no-threshold hypothesis is
that by presenting both scientific data and policies (ways of thinking) about
protection against radiation at the same time, the two tend to be confused.
The Truth About Low-Level Radiation
This is the other experts’ argument: Radiation, even when it is lower than
100 mSv, whether it be 50 mSv or 10 mSv, is dangerous. The risk of exposure
diminishes in a linear fashion but continues to exist for low level radiation.
Even the smallest exposure might pose a threat to us.
The people who stress this point of view base their assertions on the linear
no-threshold model, which as I mentioned before is merely a hypothesis,
a theory, not a scientifically demonstrated fact. The only way to get to the
bottom of this issue is to gather a very large amount of data on a very large
number of people who have been exposed to low-level radiation, but this
is not possible right now. For example, one would need data from 5 million
people to prove that development of cancer will not increase at a level of 10
mSv, and this is simply impossible with people as subjects. However, a similar
experiment has been conducted using animals at the Japanese Institute for
Environmental Sciences in Aomori Prefecture.
For 400 days, 4,000 mice (half were males, half females) lived in the same
environment and ate the same food; 3,000 of them were exposed to
radiation, 1,000 were not. Of the 3,000 that were irradiated, 1,000 were
exposed to a total of 20 mSv of radiation, 1,000 others were exposed to 400
mSv, and the remaining 1,000 were exposed to 8,000 mSv of radiation -- all
for 400 days.
In the mice that were exposed to radiation compared to the mice that were
not, life span was shorter only in the entire group that was exposed to the
maximum of 8,000 mSv, and the males of the group that were exposed to
400 mSv had almost the same life span as those that weren’t exposed. In the
females exposed to 400 mSv, a slightly shorter life span was observed. At 20
mSv, there was no shortening of life span seen for either males or females.
In these experiments using mice, therefore, it seems that there is a threshold
(borderline) between whether or not radiation exposure will have an effect
somewhere between 400 mSv and 8,000 mSv (this is admittedly a rather wide
range). In humans, exposure to 100 mSv or more of radiation causes the risk
of cancer to rise. In this range of 100 mSv or higher, higher radiation doses
clearly increase the risk of cancer; 100 mSv is therefore usually considered the
threshold, because exposure to 100 mSv of radiation increases one’s risk of 1000 200 300
0.5% 1% 1.5%
Graph representing the very slight increase in cancer mortalityat annual radiation exposures from 100 to 300 mSv
(from 100 mSv to 300 mSv, cancer mortality due solely to radiation increases from approximately 30.5% to 31.5%.)
30% of the Japanese population die from cancerNo clear increase in cancer mortality is observable as annual radiation
exposure increases from 0 mSv to 100 msv.
Out of 1000 people in the Japanese population, 305 will die of cancer; 5 of them are estimated to have contracted cancer as a result of exposure to no greater than 100 mSv of radiation.
No clear increase in cancer mortality is observable as annual radiation exposure increases from 0 mSv to 100 msv.
30% of the Japanese population die from cancer
Cumulative radiation dose in millisieverts
1716
cancer by 0.5%.
However, we do not know whether exposure to 80 or 90 mSv causes any
effects. Low-level exposure to under 100 mSv cannot necessarily be called
safe. I believe that there is a threshold somewhere under 100 mSv that
determines whether the exposure is either safe or harmful.
There is usually an effect on the human organism whenever some amount
of a harmful chemical substance in excess of a certain amount is taken into
the body. Whether this is salt or alcohol, the principle is the same: excess
amounts are harmful. Radiation is no exception, and that is why I believe that
there may be a threshold.
On the other hand, I cannot prove using humans that there really is a
threshold. In other words, it will never be possible clearly to establish
scientifically whether or not low-level radiation causes cancer rates to
increase. However, there is no doubt that even exposure at 100 mSv does not
present a large risk for developing cancer. I think it should be regarded as an
effect so small it cannot even be detected. This is why I say, “the possibility
of developing cancer due to exposure to under 100 mSv of radiation is very
small”.
Merely the Fear of Exposures Under 100 mSv Can Be Harmful
I will now tell you about the adverse effects of emphasizing that “exposure
under 100 mSv is dangerous as well” in an emergency situation, such as the
one we are currently in.
This is something that struck me when, a month after the accident at the
nuclear power plant, together with a team of radiologists from the University
of Tokyo Hospital, I visited and came into contact with local people in Iitate-
mura in Fukushima. Cancer is not the only thing that endangers our lives and
makes our lives more difficult. The stress caused by a great shift in lifestyle
(when children can’t play outside, parents are anxious and insecure about
their jobs and future, etc.) and irregular living habits (smoking, drinking
alcohol, sleep deprivation, etc.) also have very serious consequences.
As I wrote before, the problem with exposure to radiation is cancer. In this day
and age, one out of each three Japanese dies of cancer. Compared to before
and during WWII, when tuberculosis was the number one cause of death,
our lives have become increasingly affluent and convenient. Today, we eat
a lot of meat and chronically lack exercise, thanks in part to the automobile.
People smoke and drink more and their lives are full of work-related and
interpersonal stress, among other changes in our lifestyles that may induce
cancer.
By the way, tobacco smoking increases the risk of cancer twofold in males
and 1.6 times in females. If one consumes 3 servings of sake everyday (180
ml x 3) or more, one’s risk of cancer rises additionally by roughly 1.6 times. If
people really want to reduce cancer rates, they should stop smoking, drink
moderately, eat plenty of vegetables, and limit their intake of meats and
sodium. It is also important to prevent obesity through moderate exercise.
What I want to say here is that in this range of exposure of under 100 mSv,
for which there is no scientific data or proof of risk, the risk of cancer can
be increased far more by the stress and worsened lifestyle that comes from
emphasizing the supposed “dangers” of this level of radiation.
I understand the concerns of parents of small children. They want to keep
their children as far away as possible from any kind of radiation. Of course,
nothing would be better than if this could be achieved easily. But consider
that lack of exercise increases cancer risk more than exposure to 100 mSv of
radiation does.
I visited a facility for the elderly in Iitate-mura, Fukushima. The average age
of the people living there was 80, and there was even one person who was
100 years old. From my talks with the people who worked there, I came to
the conclusion that the disadvantages of evacuation outweighed the merits.
What are the (non-monetary) costs of moving to an unfamiliar location and
coping with the stress of a new environment? (Note that the annual radiation
level in this area is now under 10 mSv.) If the elderly residents of retirement
homes in Fukushima were to evacuate, they would die at three times the
usual rate. Consider also that it takes a 100-year-old person 20 years to
develop cancer, even when exposed to 100 mSv or more of radiation.
I cannot avoid thinking of the downsides to the constant scaremongering
that “even exposure to less than 100 mSv is harmful” -- said while the critics
are sitting comfortably at home in Tokyo, so far away from Fukushima, where
I saw many people and their families who cannot so easily change their
1918
lifestyles. This scaremongering is not protecting anyone from anything.
The International Commission on Radiological Protection (ICRP), itself
an advocate of the linear no-threshold hypothesis, clearly states in fact
in its report that the risk of cancer does not increase at 10 mSv (the level
currently in the villages I visited). In other words, when the level is below 10
mSv, it is even regarded as “scientifically” acceptable -- regardless of policy
considerations and other alternative ways of thinking and approaches to
“below 100 mSv” levels.
Increases in Cancer Rates Above 100 mSv
Let us look now at cases in which exposure exceeds 100 mSv. The risk of
cancer is known to increase when radiation exposure exceeds 100 mSv.
When people are exposed to over 100 mSv of radiation, the rate of death by
cancer is 0.5% higher than usual, and this rate is thought to be 1.0% higher
when the exposure is 200 mSv. Currently, the number one cause of death in
Japan is cancer, and it has been so for quite a while, because of Japan’s aging
population (cancer is a type of aging phenomenon). One out of two people in
Japan get cancer in their lives, and a third of all deaths are caused by cancer.
Under these circumstances, the death rate by cancer goes up 0.5% with
exposure to 100 mSv. This does not mean, however, that if you had one-tenth
the exposure (10 mSv), your risk would only increase by one-tenth (0.05%). As
I wrote above, this is because the increase in the range under 100 mSv cannot
be scientifically determined or calculated.
Fact: We Are Exposed to 1.5 mSv of Radiation Annually
People are scared when they hear about “radiation” or “exposure.” This
is understandable. After the nuclear accident, there were families that
evacuated to Western Japan. Many foreigners returned to their home
countries. Perhaps a feeling came into play that anywhere that is farther away
from the Fukushima nuclear power plant would be safer.
However, there is already, practically everywhere on our planet, radiation
other than the radioactivity caused by the nuclear accident or the fallout
from atmospheric nuclear weapons testing that I mentioned earlier. Did you
know that we are exposed to radiation on a daily basis? Cosmic rays (radiation)
from outer space have been falling on the earth since its formation. There is
radiation emitted from the earth (rocks) and minerals, radiation from radon in
the atmosphere, and radiation in radioactive substances included in our food.
People are exposed to this kind of radiation every day.
People in Japan are exposed to an average of 1.5 mSv of natural radiation.
This 1.5 mSv is a low figure by international standards. This is because Japan
has few natural resources and few minerals that emit radiation. However,
there are differences between regions.
Geologically, Western Japan is rich in granite containing large amounts of
radioactive materials, making the average exposure 1.5 times higher than in
Eastern Japan. If we limit our discussion now to natural radiation, it turns out
that those who fled to Western Japan evacuated to a region where they are
exposed to higher levels of radiation.
Since volcanic ash from Mount Fuji’s eruption (loam) covers the ground
surface in the Kanto Plain, this has the effect of blocking radiation emitted
from rocks deep underground. The Kanto’s loamy soil is why Kanagawa and
Tokyo have the lowest exposure to natural radiation in Japan.
Mount Fuji is so high that the atmosphere becomes thinner at the summit.
Everywhere on Earth, the atmosphere serves as a protective film against
cosmic rays falling on us; its protective effects become weaker at the summit
of tall mountains, where the atmosphere is thinner -- and the radiation level
is as much as five times that on the surrounding plain.
Out in outer space, beyond the Earth’s atmosphere, there is even more
radiation flying around. A person who spends one day in space is exposed to
2/3 of the amount of natural radiation they would be exposed to on Earth in
one year (in Japan).
The reason why astronauts return to Earth after about six months is that, by
then, their exposure to radiation has passed what is considered the limit and
there will be negative effects on their health if they stay.
Living on the ocean’s surface is the best way to avoid being exposed to
natural radiation. It is the farthest from outer space, with no earth underfoot.
This does not mean, however, that there is less cancer among sailors.
The average annual exposure to natural radiation in Japan is 1.5 mSv, but
at the global level, the figure is a bit higher, 2.4 mSv. In Guarapari in Brazil,
2120
annual natural radiation exposure is as high as 10 mSv. In the state of Kerala
in southern India, annual exposure is 4 mSv, but at high altitudes it exceeds
70 mSv. The reason for this is the relative abundance there of the mineral
monazite, which contains radioactive thorium -- but a study conducted by
Kagoshima University found no increase in cancer rates in this region. In
Iran’s Ramsar region, famous for its hot springs and the Ramsar Convention
on Wetlands, there are places where annual exposure to natural radiation
exceeds 200 mSv, but there are no reports that the incidence of cancer is
higher there. Incidentally, regions with hot springs generally have higher
exposures to natural radiation. The famous Arima hot springs resort, one of
Japan’s oldest, is also a “fountain of radioactivity”.
The average annual exposure to natural radiation in the US, at roughly 3 mSv,
is about twice that in Japan. Note also that a round-trip airline flight between
Narita and New York exposes people to 0.2 mSv of radiation (because of the
high altitude and exposure to cosmic rays). For example, if frequent flyers
like trading company representatives go back and forth between the US and
Japan seven times, they are exposed to 3 times the annual natural radiation
levels of Japan. However, there are no data showing that employees of
trading companies or pilots have increased risks of developing cancer.
Of course it is not just humans: all living creatures on Earth are exposed
to radiation. From the time 3.8 billion years ago when life began on Earth,
organisms have been continually exposed to radiation. But radioactive
substances constantly lose some of their radioactivity as time passes; thus
the level of natural radiation in the past was presumably higher than it is
now. To undo the damage to cells caused by radiation, living organisms have
developed repair mechanisms.
Radiation Destroys DNA
Let me explain a bit about radiation and how living organisms work. The key
to the effect that radiation has on life is in organisms’ genes, or DNA. DNA,
which controls life, is composed of two very thin threads that are twisted
around each other. Radiation breaks these threads. Skin disorders such as
sunburn occur when people are exposed to ultraviolet rays. The rays break
the DNA of cells in the surface layer of a person’s skin. When a person is
exposed to ultraviolet rays, they stop at the skin surface; ionizing radiation
(the kind we are talking about here) is stronger and can penetrate deeper: it
has the frightening power to break the DNA of cells of organs deep inside the
human body.
How the Human Body Repairs Itself
Life cannot continue if our DNA continues to be destroyed. Fortunately,
cells have the ability to repair their DNA. For 3.8 billion years, DNA has been
destroyed and repaired over and over again by living cells. Life has adapted
to the damage that radiation causes, and has found a good way to cope with
it. (Or to be more exact, only the species that were able to overcome the
effects of natural radiation have survived natural selection.)
Even if people are exposed to amounts of radiation slightly above natural
levels, the body can respond by repairing the broken DNA. However, when
the level of exposure is too high, DNA is broken simultaneously in many
places, and the body cannot repair these in time to prevent the cells from
dying. It is something like what happens when many accidents occur at the
same time and there are not enough ambulances to respond to all the calls.
In other words, the effect of radiation exposure on the human body does
not depend on whether the person was exposed to radiation or not, but
rather on the amount of radiation that the person was exposed to at one
time. Therefore, if somebody is exposed to 1.5 mSv annually for 80 years, the
total amount of exposure will be 120 mSv. The workers in the nuclear power
plant where the accident occurred were exposed to 120 mSv of radiation in
the space of a few days. The same 120 mSv of radiation has a much different
effect on the human body in this case. This is why the situation of workers in
nuclear power plants worries me very much.
Radioactivity Decreases Over Time
It is easier to understand the relationship between radiation, radioactive
materials, and radioactivity by analogy to a candle.
Let us say that the candle represents a radioactive substance and its state
when it is burning represents its having radioactivity. Radiation is the light
emitted from the flame. As time passes, the candle becomes shorter. When
the candle eventually dwindles to nothing, the fire goes out as well. This is
when its radioactivity ends, or when radiation from it becomes zero. The time
2322
it takes the candle to become half of the length that it was is the half-life.
Just as different candles burn for different durations until they are halfway
consumed, half-lives vary as well. One of the characteristics of radioactive
Iodine-131 is that its half-life (the time it takes for the candle to burn down
to the halfway point) is eight days -- very short. After eight days, the amount
is halved, and after an additional eight days, the amount becomes one
fourth. Eight days after that, it will become one sixteenth. After roughly three
months, the amount of radiation becomes less than 1/1000 of what it was
initially.
Cesium-137, on the other hand, has a half-life of roughly 30 years;
Strontium-90 has a half-life of about 28 years; and Plutonium-239 has a half-
life of 24,000 years. These half-lives have a very important meaning for how
we interpret the effects of radioactive substances on the human body.
Candles with short half-lives burn like short, fat candles. They emit a lot of
energy quickly, for a short time, but on the other hand, they do not last long.
When these kinds of radioactive materials are released into the environment,
the initial response is crucial. After the Chernobyl accident, the initial
response to the need to impose food restrictions was late; thyroid cancer in
children increased as a result.
On the other hand, radioactive materials that have long half-lives are like thin
candles that burn for a long time. They emit radiation a little bit at a time, so
the response must be long-term: it’s a lasting relationship.
When DNA Can and Cannot Be Repaired
Perhaps you have read newspaper accounts of what is going on at the site of
the nuclear accident that read like this:
“If a person works in this location for one hour, the exposure will amount
to the limit set for one year.” In other words, workers get a one-year
maximum allowable dose in one hour.
I mentioned this a little bit earlier, but the effects on the human body differ
depending on whether the person was exposed to a certain amount of
radiation for a short time, or if the person is gradually exposed to the same
amount of radiation over a long period.
To imagine what is happening, it may help to compare this to taking a bath.
If someone is in an empty bathtub, and a big bucketful of hot water at 45
degrees Celsius (113 degrees Fahrenheit) is poured into the tub suddenly, the
occupant will be startled, to say the least. But if the same amount of water at
45 degree Celsius flows gradually from the faucet into the tub, our bather can
enjoy his bath.
If a person is suddenly exposed to large amounts of radiation, the body
cannot repair the damaged DNA in its cells quickly enough. On the other
hand, if the radiation is gradual and in small amounts over a long period of
time, even if the total amount of exposure is the same, the body will be able
to repair the damaged DNA.
The risk of cancer increases with exposure to more than 100 mSv of radiation.
This means that the risk increases when people are exposed daily, little by
little, and the total amount is 100 mSv over a year’s time. As a result of the
nuclear accident, the Tokyo metropolitan area, over 200 kilometers away, had
readings of radiation in the air of 1 microSv/hour. If people continued to live
where radiation continued at this level into the future, it would take 11 years
or so for the total exposure to reach 100 mSv. But as I have explained already,
when people are exposed to small amounts of radiation over a long period of
time, there is less effect on the human body.
Radioactive Substances Spread Like Pollen
Now, let me write about the how radioactive materials spread over great
distances. Just like pollen, radioactive materials are carried to other places by
the wind. In the case of radioactive materials, this “pollen” emits a special kind
of ray called radiation.
A good example would be to liken a nuclear reactor to a large cryptomeria
tree (known as sugi in Japanese). Cryptomerias release huge amounts of
pollen, and most of this pollen is carried off by the wind. So much pollen
is released that you cannot approach the tree when it is showering pollen,
even if you try: there is just too much. Similarly, workers at a nuclear power
plant cannot get as close to the reactor as they would like in order to work on
it while it is highly reactive. Even if someone is far away from the giant sugi
trees, pollen (which we are likening to radioactive substances) is carried by
the wind, sticks to a person’s body, and enters the body when that person
2524
eats or breathes it in.
We can say that now there are no longer any radioactive substances from the
Fukushima Daiichi accident in the air, but while radioactive substances are
still in the air, the proper thing to do is to wear a mask, close all windows, and
take other protective measures. This has some effect, but the effect is limited.
Being inside a concrete building rather than being outside is better: it can
decrease your exposure to radiation to less than 20% of that outside.
Radiation Levels Depend on Wind, Rain, and Terrain
Kashiwa-shi in Chiba Prefecture, located roughly 200 km away from the
Fukushima nuclear power plant, is referred to as a “hot spot.” There are also
locations within Fukushima with high radiation readings and other locations
with low readings. This occurs because radioactive substances spread in a
characteristic way.
As we said, radioactive substances are carried away from their source by the
wind, just like pollen. Furthermore, they do not spread evenly or all at once,
but characteristically move in clusters, called “plumes.” Generally, the farther
away from the nuclear power plant a person is, the less effect its radiation will
have. However, this may change with conditions such as the direction and
strength of the wind and the shape of the terrain.
Rainfall is another factor just as important as wind. There are locations such
as Katsushika-ku and Adachi-ku in the Tokyo metropolitan area and Kashiwa-
shi in Chiba Prefecture (also in the north-east Kanto region) located a long
distance away from Fukushima that recorded high levels of radiation after
the accident. This is because the radioactive substances that were carried
westward by the wind from Fukushima were absorbed by the rain and fell to
the ground there. Winds that carry plumes blew into the Tokyo metropolitan
area on March 15th and March 21st of 2011; it is thought that Kashiwa-shi in
Chiba Prefecture is where the wind met the rain on those two days. Since the
cesium included in the radioactive plumes heading westward gradually fell
to the ground with the rain, the external exposure to radiation in Setagaya-ku
and other parts of western Tokyo was less than the exposure in the eastern
parts of the city.
(2) The Truth About Internal Exposure
What Is “Internal Exposure”?
There is a famous academic personality who appears often on Japanese
TV and writes in magazines who announced publicly that he “won’t buy
vegetables grown in the area from Miyagi Prefecture to Kanagawa Prefecture”
(quite a vast range). He probably means to say that he is afraid of internal
exposure to radioactivity caused by eating contaminated vegetables.
In October, 2011, the Food Safety Commission drew up a report stating
that the total cumulative level of exposure capable of exerting an effect on
health due to ingestion of food over a person’s lifetime is a figure in excess
of approximately 100 mSv. As long as people eat food that is sold in ordinary
supermarkets, the amount of exposure falls within this range, so there is
nothing to worry about.
But What, Then, Exactly Is “Internal Exposure to Radiation”?
There are two types of exposure to radiation. One occurs when people are
exposed to radiation externally (outside their bodies, in other words). Internal
exposure occurs when radioactive substances enter someone’s body and
their body is exposed to radiation from the inside. External exposure to
radiation occurs when radiation from a radioactive substance gets attached
to clothing or skin. Internal exposure occurs when radioactive materials in the
air are inhaled or a radioactive substance is taken in with food.
When asked which they are more afraid of, many people tend to be more
afraid of internal exposure. Perhaps people get the idea that once the harmful
materials enter the body, they will be deposited there and continue to have
harmful effects for the rest of their lives.
I think there is a historical precedent for this that influences people’s
attitudes. The first case of environmental pollution that drew the general
public’s attention in Japan was Minamata disease. Fish in Minamata Bay
had ingested (taken in) harmful levels of mercury from their environment,
and these levels built up; when people further up the food chain ate fish
containing these high concentrations of mercury, tragedy resulted. Perhaps
internal exposure reminds people of the tragedy of Minamata disease.
However, radioactive substances, unlike heavy metals such as mercury, are
2726
metabolized and excreted if they enter the body. This difference with respect
to heavy metals is crucial.
The Dangers of Internal Exposure
I understand why people respond with fear to internal exposure, but 1 mSv
of internal exposure is not more dangerous than 1 mSv of external exposure.
The effects are exactly the same.
First of all this is because the “sievert” unit indicates the effect of radiation
on the human body; for the general public, however, it is represented as an
index of the increased risk of cancer.
The effects of internal radiation manifest themselves inside the human body;
therefore they cannot be seen, but there is something called a “committed
dose” that quantifies their effects. When radioactive substances are taken
into the body, they do not necessarily remain there intact. Metabolism and
excretion rid the body of these materials over time, and their radioactivity
lessens in proportion to their half-lives. The committed dose indicates the
overall amount of internal radiation to which a person will be exposed over
a lifetime from the moment of ingestion, based on the assumption that the
effect weakens over time. It clearly expresses one aspect of the threat of
internal radiation: one never knows when the exposure will end.
Radioactive Material in Food
There is radioactive material in the food that we eat every day. A radioactive
substance called Potassium-40 is contained in such vegetables as spinach,
for example. Potassium-40 is a substance that is essential for the growth of
organisms, and people take it in on a daily basis when they ingest vegetables.
Even when ingested, this will eventually leave the body via metabolism and
excretion, but more will enter the body when the person eats vegetables
again, so there is always about 4,000 becquerels of Potassium-40 in the body
of an adult male weighing 60 kg. Roughly 0.2 mSv of internal radiation occurs
annually due to Potassium-40. If a person lives 100 years, this will add up to
20 mSv.
This means that the more vegetables a person eats, the more internal
exposure increases. However, consuming vegetables is known to greatly
decrease the risk of cancer. From this we can say there is no reason to worry
about internal exposure to radiation from Potassium-40.
The Truth About Exposure to Cesium
As I mentioned before, very small amounts of strontium and other radioactive
substances were released from the nuclear power plant after the accident.
However, the amounts of these substances are not sufficient to affect a
person’s health, so we can say that in reality it is the radioactive iodine and
cesium that are threats to health. Keep in mind that the radioactive isotope
Iodine-131 has a half-life of eight days; currently, ten months after the nuclear
accident, it is undetectable, so the only problem material remaining is cesium.
This cesium has been detected in levels above regulatory limits in beef and
in tea from Shizuoka, causing increased concern about food. The wind is
responsible for carrying this radioactive cesium over and across the Tokyo
metropolitan region to Shizuoka, on the far side of Tokyo from Fukushima.
The radioactive Cesium-137 that was released after the nuclear accident has a
half-life of 30 years. Once inside a human body, almost 100% of it is absorbed
in the gastrointestinal tract. However, the cells in the human body are
constantly being replaced, so it takes the body about two or three months to
excrete half of the amount ingested. In the case of infants, half of the amount
is excreted much faster: in ten days.
To recall what we know from Chernobyl, radioactive iodine and cesium were
scattered across a wide area by the blast when the nuclear reactor exploded.
Ultimately, the result was a confirmed increase in the rate of thyroid cancer in
children due to the ingestion of milk contaminated with Iodine-131, because
no restrictions were imposed on food intake in Chernobyl. Thus there was
also internal exposure to radiation from cesium for the same reason. When
scientists conducted a local study at Chernobyl of cesium in the bodies of
roughly 200,000 people, mostly children, they found amounts of Cesium-137
had risen from a few hundred becquerels to tens of thousands of becquerels
after the accident. However, to this day, cesium has not been confirmed to
have caused any cancer in these people.
We learned, in other words, that thyroid cancer was caused in children due to
2928
Iodine-131, but adverse effects of cesium have not been observed.
Note that cesium is chemically similar to potassium; both are both alkali
metals. There is far more radioactive potassium detected in our bodies than
radioactive cesium from Fukushima. Consequently, I do not think there is any
reason to be excessively concerned about internal exposure to radiation from
cesium.
(1) What Causes Cancer?
Japan, World Cancer Record Holder
Japan has the highest rates of cancer in the world, and the number of people
who get cancer is still increasing. Every year, roughly 650,000 people are
newly diagnosed with cancer and 1.5 million people are receiving treatment
for it. And every year, 350,000 people die of cancer in Japan.
It is estimated that roughly one out of every two Japanese people gets
cancer. The rate is 60% for males, and 40% for females. What many people
worry about in connection with the nuclear accident at Fukushima is the
possibility of cancer rates rising due to radiation. So will there be more thyroid
cancer? How about leukemia? What kind of effect will it have on the health of
children? I’m sure that parents, especially those who have small children, are
worried sick when thinking about this.
What causes cancer in the first place? Roughly speaking, one third of the
overall causes for cancer can be attributed to cigarettes, another third to
alcohol, diet, and so called lifestyle. The remaining third can be attributed
to (bad) luck; no matter how ideal a lifestyle one lives, there is no way to
completely avoid cancer.
Those are the facts. Two-thirds of the causes of cancer are lifestyle-related.
Ten months have now passed since the nuclear accident; the amount of
radiation in Fukushima has now settled to levels that will not affect a person’s
health.
I will write in more detail in Chapter 6 about the situation in Fukushima, but
even if a person lives exposed to current levels of radiation, there will be no
increase in cancer. However, I must emphasize one thing: two-thirds of the
causes of cancer are lifestyle-related. Therefore the possibility that cancer
risk will actually increase in the wake of the accident cannot be excluded
because more people are feeling more stress about their impaired lifestyle as
they evacuate for an extended time period in an unfamiliar place, even if the
amount of radiation decreases.
I believe that if people sacrifice their lifestyle in fear of low-level radiation
Chapter 2Cancer Risk Facts
3130
(which causes almost no increase in cancer risk), the cancer risk is sure to
increase due to this worsening of their lifestyle. Of course, all this was caused
by the nuclear accident, so I blame the nuclear power industry for the harm it
has done.
In this chapter, I would like to give a detailed explanation of the mechanisms
involved in cancer formation so that you can have a proper understanding of
cancer and, as much as possible, avoid the risks.
Why Do People Get Cancer?
The human body consists of roughly 60 trillion cells. Roughly 1% of these die
every day. The reason that hair falls out and old skin peels off is because the
cells are dying. It is said that 600 billion cells die every day.
If all of our cells died, life would not be unsustainable, so living cells divide
and multiply to make up for the dead cells. There is a need to copy DNA,
which is the genetic blueprint of the cell, in its entirety in order to divide a
living cell. This is something that humans do, so errors sometimes occur.
For instance, sometimes a cell is born that is different from the original cell it
came from. This is the phenomenon known as mutation. These copying errors
in cell DNA during cell division can be attributed to tobacco and alcohol use,
chemicals and stress, aging, and exposure to radiation.
Of the cells that are born from a mutation, on rare occasions there are “cells
that do not die”. These will endlessly continue to divide and grow. These cells
that do not die are cancer cells. If the environment is just right, bacteria will
continue to live and divide forever. Cancer is the same in this aspect.
According to one theory, some 5000 cancer cells are produced daily in
the normal human body, once it reaches a certain age. Under normal
circumstances, our immune cells would win 5000 battles every day without
losing a single time in their fight to kill off cancer cells.
There is a catch, however: because immune cells are there to detect, attack,
and kill foreign objects, it is hard for them to recognize cancer cells as being
foreign objects, because they are replicas of our normal cells.
For instance, let’s say I have cancer. My cancer cells will be zombie-versions
of “Nakagawa cells”, so they could also be called “former Nakagawa cells”
or “pseudo-Nakagawa cells”. It is hard for immune cells, whose mission is
to eliminate foreign cells, to see these cancer cells as foreign, because they
are so similar to my own cells. There is always a risk that immune cells will
overlook them.
The Longer the Average Life Expectancy, the Higher the Cancer Rates
Sooner or later, a cancer cell that has slipped through the dragnet laid by
the immune system will quietly begin reproducing and proliferate (increase
in number). That is how cancer starts. It will take from 10 to 20 years for it to
grow to a detectable size (roughly 1 cm).
As people get older, the damage to their DNA caused by lifestyle builds up
and it becomes easier for cancer to occur. Since their immune functions also
deteriorate, elderly people become more susceptible to cancer.
On the other hand, let’s say (although it’s horrible to imagine) that my cancer
cells were injected into another person. In that case, the cancer cells from my
body inside that person’s body will all be killed. That is because, that from
that person’s immune cells’ point of view, my cancer cells are clearly foreign
and therefore every one of them will be killed. Therefore, cancer does not in
general get transmitted to other people.
One out of every two Japanese gets cancer, and one out of three dies from
cancer. Japan has the world’s highest cancer rates. The reason for this is that
Japan is the country with the world’s longest life expectancy. Cancer is an
aging phenomenon.
Before and during WWII, tuberculosis was the leading cause of death.
Takuboku Ishikawa died at age 26, and Ichiyou Higuchi at 24, both from
tuberculosis (both were great Japanese writers of the early 20th century).
They did not reach the age at which cancer commonly occurs. During the
Meiji and Taisho periods (from the mid-1800s to the 1920s), when the
average Japanese life span was short, many people died of tuberculosis and
infectious diseases before they developed cancer. (The life expectancy of
many countries in Africa today is in the 40s, so I doubt there are many cases
of cancer there.)
The reason that cancer kills is because ageless, indestructible cells are created
3332
in our bodies. When we realize that these cells reproduce indefinitely, it is
ironic to think that eternal youth and immortality, which humans have been
dreaming about throughout the ages, can kill them.
Our Growing Population of “Youthful” Seniors
Cancer rates start to increase in people in their 40s, and continue to increase
as people get older. I sometimes hear people say that it’s hard for elderly
people to get cancer, but that is not true. Cancer continues to increase, even
when people are 80 years old, even when they are 90.
The fact is that much of the cancer in elderly people has been with them
since middle age. This is because the cancer cell that slipped through the
immune cells’ dragnet took 20 years to become 1 cm in diameter.
It is only natural that cancer, a symptom of aging, is increasing in a country
such as Japan, where life expectancy is the longest in the world. That does
not mean, however, that nothing should be done about the increase in
cancer in the elderly population.
Our elderly population is, in a sense, getting “younger”. Instead of retiring,
they want to continue being active and working hard, contributing to society
-- and that is also what society wants.
For example, Namihei, the father in “Sazae-san”, a manga that was started 60
years ago, is supposed to be 54 years old. Singer Go Hiromi is now almost the
same age as Namihei. Born in 1955, Go Hiromi will be 56 years old this year
(2011), but does not look the same age as Namihei, no matter how you look
at this difference.
At the time the Sazae-san manga series was written, people in their 50s were
one step away from retirement, but these days many Japanese in the same
age group are still active. Namihei’s wife, Fune, is 48, and popular singer Seiko
Matsuda is 49. I cannot believe these two individuals are supposed to be
almost the same age.
I have been invited many times to the same lectures as journalist Shuntaro
Torigoe. One day he said to me, “There’s no way I’ll ever get cancer”. Later,
he did get cancer, though, and he wondered, “How could I, of all people, get
cancer?” Mr. Torigoe has now undergone four surgeries for rectal cancer --
and is still currently very active as a journalist.
Your Chances of Getting Cancer Are 50-50
Even when people hear that one out of two people will get cancer, they
think it is someone else’s problem. Many people may think wishfully that
they will be OK, and will end up among the lucky 50% that do not get cancer.
However, even if that person has an “ideal” lifestyle, there is still a 20% to
30% risk of developing cancer. This is because there is also an element of
luck involved. Some people are heavy smokers and also drink heavily. The
people around them may think that they will no doubt be diagnosed with
lung or liver cancer, but those people refuse to even consider changing
their lifestyle. And some people like this will even live until they are 90 years
old. Conversely, there are people who don’t smoke cigarettes, eat mostly
vegetables, and exercise regularly. Even people who live ascetic lives like this
have a chance of developing cancer.
Magic Bullets For Cancer? (Only Lifestyle Improvement and Early Detection Work)
However, if you compare 1000 heavy smokers with 1000 ascetic quasi-saints,
the heavy smokers’ rates of cancer will probably be overwhelmingly higher.
It is believed that the risks of developing cancer are decreased by from 20%
to 30% by making judicious lifestyle choices. There are cases, on the other
hand, where luck is not on the side of the person concerned, however ascetic.
Therefore, it is not enough to be cautious about one’s lifestyle choices: it is
also important to undergo proper cancer screening and work toward early
detection.
In other words, the wonder drug for not dying from cancer, the only one, is
an improvement in lifestyle and early detection of the disease.
Many different things cause cancer. Tobacco is top on the list of causes, but
drinking too much, not eating enough vegetables, and consuming too much
meat (especially processed meats such as ham and sausage), high salt intake,
and lack of exercise also cause cancer. Cervical and liver cancer are caused
by viral infections, and stomach cancer is mainly caused by infection by
Helicobacter pylori.
Total Cancer Rates Would Be Cut by 20% if Nobody Smoked
The biggest cause of cancer is tobacco smoking, and second to that is alcohol.
3534
Tobacco is the largest man-made disaster of the 20th century, and claims
the lives of five million people every year. It is also the top-ranking cause of
cancer.
If no one in Japan smoked tobacco, it is estimated that roughly 20% of
Japanese cancer cases would not occur. (The reduction would be 30% for
males, 3% or 4% for females.)
As for the types of cancer, Japanese men generally get laryngeal, lung, and
esophageal cancer. Other things being equal, the risks of these cancers
occurring are increased by 33 times, 4.4 times and 2.3 times respectively, by
smoking tobacco. In addition, tobacco use increases pancreatic cancer, liver
cancer, stomach cancer, and most other cancers as well. There are roughly
4,000 types of chemicals in tobacco smoke. Among these are roughly 60
types of known carcinogens, such as nitroso compounds, aromatic amines,
acetaldehyde, and arsenic.
It is not only one’s throat, windpipe, and lungs, which come into direct
contact with tobacco smoke, that are affected: carcinogens are carried
through the bloodstream and affect almost all your organs. Many
carcinogenic substances cause mutations when they are activated by
enzymes in the body and bind to genes in the process of cell duplication. It is
thought that the damage to damaged genes created in this way accumulates
with continued exposure to carcinogens, and that this changes healthy cells
into cancer cells.
I don’t smoke. The reason why I chose not to smoke is that even second-hand
tobacco smoke has carcinogenic effects. Tobacco is not something whose
consequences affect just the smokers themselves. If a woman’s husband
smokes more than one pack of cigarettes a day, her risk of developing cancer
doubles, even if she herself does not smoke. Filters on cigarettes function to
remove carcinogenic substances from the smoke that the smoker is inhaling.
However, they do not filter the smoke breathed by those around the smoker.
To make matters worse, tobacco smoke becomes more carcinogenic as its
temperature decreases.
In other words, the smoke that people around the smoker are inhaling is
more dangerous than the smoke that the actual smoker is inhaling. If you do
not want to lose your family to cancer, I recommend that you quit smoking
tobacco at once. By quitting smoking, you will reduce the risk of developing
lung cancer. The longer someone resists the urge to smoke and refrains from
smoking, the lower that person’s risk of lung cancer becomes. Ten years after
one quits smoking, the risk becomes one-third to one-half of what it was. But
it takes longer to reduce the risk of lung cancer than to reduce the risks of
other diseases: the risk of heart disease, for example, decreases almost to the
level of non-smokers more quickly, in 5 to 10 years after quitting smoking.
The Younger the Smoker Is, the Greater Tobacco’s Effect on the Human Body
All this does not mean, however, that one will be cancer-free for the rest
of one’s life just because one has quit smoking. And there are also heavy
smokers who do not get cancer. That is why some people claim that tobacco
smoking and cancer are unrelated.
Yet the risks of cancer are undoubtedly much higher for smokers than for
non-smokers. We can liken cancer to an invisible spear that falls unexpectedly
from the sky, totally “out of the blue”. As one’s age increases, the frequency
with which these spears fall increases -- and so does the incidence (occurrence
rate) of cancer. If a person smokes, the frequency of those sudden and
invisible spear attacks is even greater. If on the other hand the person
exercises and has a diet of mostly vegetables, the frequency of these spear
attacks can be decreased. The important thing is to realize that, no matter
how careful somebody is about their health, they may eventually be hit, and
conversely, heavy smokers may escape unscathed throughout their lives.
What we know with certainty is that smoking tobacco increases the risk of
getting cancer. The best defense against cancer is to refrain from smoking.
Alcohol + Tobacco = Double the Rate of Cancer
After tobacco, alcohol is the leading cause of cancer. In addition to directly
affecting membranes in the mouth, throat, and esophagus, it puts a
burden on one’s liver, and as a result may cause oral, pharyngeal, laryngeal,
esophageal, hepatic (liver) and other types of cancer. These cancers can be
called alcohol-related cancers.
According to a study conducted by the Ministry of Health, Labour, and
Welfare that tracked over 70,000 people across Japan for ten years, the risk
3736
of cancer for males who drink on average between two and three servings
of sake per day was 1.4 times greater, and this risk was 1.6 times greater for
those who on average drink three or more servings of sake per day.
One serving of sake is equivalent to one large bottle of beer or two glasses of
wine (240 ml) or one whiskey double. According to these figures, 13% of all
cancer occurs in people who drink two or more servings of sake per day. The
risk is especially high for those who both drink alcohol and smoke tobacco.
In males, the group that drinks on average two or three or more servings of
sake per day has a 1.9 times greater risk of getting cancer, and the group of
males who drink on average three or more servings of sake per day has a 2.3
times greater risk of getting cancer. At the very least, I recommend that you
absoutely avoid one of the two.
Let us look now at the figures for colorectal cancer: males who drink two
or more servings of sake on average per day and who also smoke tobacco
have a 3-times-greater risk of cancer than someone who neither smokes nor
drinks. This means that if alcohol and tobacco disappeared from the face of
the planet, roughly half of the colorectal cancer in males would disappear.
By the way, I don’t smoke, but I do like to drink alcohol. Getting cancer
because one smokes is one’s own fault, but the blame for smoking does not
stop there, since it increases cancer risk for other people as well. With alcohol,
calling the risk incurred one’s own fault, taking responsibility for it, and being
able to say the buck stops there is the good thing about drinking. (This may
sound like a self-serving excuse for myself, being a drinker...)
I regard being able to enjoy both sake and wine as among the privileges of
being born in Japan. However, it is not good to drink too much. Limit yourself
to two servings a day, and set yourself some alcohol-free days to give your
liver a rest. I try to do that myself (but I have to admit it may be merely a goal
that I’ll never achieve).
Drinking Can Give You Cancer!
There are people whose faces turn red when they drink alcohol. Though they
are not tee-totalers, they ought to be. They have to be careful. They are at a
very high risk of getting cancer.
The ethanol contained in alcoholic beverages is broken down into
acetaldehyde in our livers. Ethanol is not toxic: it is even used as a disinfectant;
but acetaldehyde can cause cancer. Aldehyde dehydrogenase-2 (ALDH2) is
an enzyme that breaks down acetaldehyde to acetic acid and detoxifies it.
The type of ALDH2 you have is determined genetically. There are both normal
genes for ALDH2 that have a strong ability to break down acetaldehyde, and
defective deleted genes that cannot do this well.
You inherit one of the two gene types that your parents pass down to you.
Roughly 5% of Japanese have inherited the deleted gene type from both
parents. These people can’t drink any alcohol; they are tee-totalers, non-
drinkers. Non-drinkers, being unable to drink alcohol, do not increase their
risk for cancer by drinking because they do not drink. They are safe.
Acetaldehyde does not accumulate easily in people who inherit normal genes
from both parents, so the good news is they have a decreased risk of cancer;
the bad news is that they can become alcoholics if they drink too much.
Most westerners fit in this genetic category, so people who cannot drink any
alcohol at all are rare in Europe and the US.
The problem occurs when either of the genes inherited from one’s parents
is the “deleted” type. Those who get red-faced when they drink are people
who can drink, moderately. Between 30% and 40% of Asian people fit in this
category. If these people drink a lot of alcohol, their risk of cancer increases.
It happens this way. There are no carcinogens in alcohol in itself. However,
the acetaldehyde produced when alcohol is broken down is carcinogenic.
Someone might inherit one type of ALDH2 gene for the enzyme that
detoxifies this from one parent and the other defective type from the other
parent. This “heterozygous” person has a reduced ability to break down
acetaldehyde but will be able to drink moderately.
Even so, the heterozygous people with a combination of functioning and
defective genes cannot completely break down acetaldehyde. It is the
acetaldehyde that is not broken down and remains in the body that causes a
person’s face to turn red.
This may not be something that drinkers would like to hear, but when their
faces turn red, it means that the carcinogen acetaldehyde in their bodies is
not being broken down and remains in their bodies. Some people say “When
I was younger my face turned red, but now I’m okay.” Unfortunately, this does
3938
not mean that the person’s ability to break down carcinogens has increased.
It just means that their bodies got used to acetaldehyde: it is no reason to feel
at ease.
(2) How to Prevent Cancer
The Seven Pillars of Cancer Prevention
I have mentioned the two main causes of cancer, but a variety of other causes
exists, such as insufficient intake of vegetables in one’s diet, obesity, viruses,
etc. Here I would like to sum up for you the lifestyle choices that are most
likely (but not guaranteed) to help you avoid cancer.
1. Don’t smoke.
2. Drink no more than one serving of alcohol per day.
3. Add lots of vegetables to your diet and avoid eating always the same
things.
4. Decrease your salt intake.
5. Exercise regularly.
6. Stay as fit and trim as you were when you were younger.
7. Avoid catching viral and bacterial infections.
It is not always easy for people today to put these seven principles into
practice. We should try nevertheless to decrease our risk of cancer as much as
possible by keeping these things in mind.
Early Detection: Finding the Disease Before Symptoms Appear
The important thing here is early detection. However, in the case of cancer,
early detection does not mean going to the hospital to have tests conducted
as soon as one is not feeling well or after symptoms appear. You must go
before you feel unwell.
The most typical symptom of cancer is pain. This is usually due to bone
metastasis (spreading of cancer to bones from some other organ). Since a
complete cure is unlikely if you already have metastatic cancer, pain caused
by cancer means it is already very difficult or impossible to treat.
Furthermore, cancer that is detected early has not yet produced symptoms in
any organs. It is necessary to get periodically screened while one thinks one is
healthy and free of cancer.
Early detection of cancer is practically synonymous with cancer screening. Let
us talk about breast cancer. Physicians call tumors smaller than 2 cm “early-
stage” cancer. Cancer smaller than this can be treated.
It takes a cancer cell roughly 20 years to grow to 1 cm as it escapes attacks
from immune cells. But once cancer cells start growing, their growth
accelerates. A cancer cell takes only a year and a half to grow from that 1
cm to 2 cm. Cancer cells can be 2 cm, 1 cm, or even 1 mm. Whatever the
size, they are cancer cells. However, a cancer cell that measures only 1 mm
across cannot be diagnosed as cancer. Roughly speaking, cancer cannot be
diagnosed until the cancer cell is 1 cm in diameter.
In other words, early detection has a time limit, and that time limit is the year
and a half that it takes cancer cells to grow from 1 cm to 2 cm, when it still
can be cured. This is the reason for the need to have periodic screenings once
every one or two years.
In the long lifetime of a cancer cell, the window of opportunity for early
detection through screening is only a year and a half. If a person undergoes
cancer screening once every one to two years, even if they do get cancer, in
theory it will be caught in time, while it is still “early-stage cancer”.
Comparing Exposure to Radiation vs Lifestyle Choices
Let us get back to our topic: the relationship between exposure to radiation
and cancer. Two-thirds of the causes of cancer are attributable to lifestyle
choices ranging from tobacco and alcohol use to vegetable-deficient diets
and failure to exercise, as I have stated earlier.
There is also exposure to radiation, which does cause cancer. Unlike the
lifestyle choices that people make on their own, the exposure to radiation
from the Fukushima nuclear power plant accident has put people from
infants to the elderly at risk for cancer, regardless of whether they are aware
of or responsible for it. This cause of cancer is the most insidious.
To what degree are the dangers from each of these two types of causes of
cancer comparable? A study was conducted by the National Cancer Center of
Japan.
Take a look at the table on the next page.
4140
You’ll see, for instance, that it examines the risk of developing cancer due to
exposure to 100 mSv of radiation. At this level, radiation does increase the risk
of cancer, but so do second-hand smoke and a vegetable-poor diet, which
carry comparable risks. Similarly, excessive drinking carries a very high risk of
developing cancer.
The study compared findings of papers published by the Radiation Effects
Research Foundation and other research organizations that examined
rates at which cancer developed over extended periods of time in roughly
44,000 people who were exposed to radiation from the atomic bombings
of Hiroshima and Nagasaki with epidemiological studies conducted by the
National Cancer Center to measure cancer risks due to people’s lifestyle
choices.
According to this study, a group that was exposed to 100 to 200 mSv of
radiation due to the atom bombs had a 1.08 times greater risk of developing
cancer than those people who were not exposed. Compared to the cancer
risks involved in lifestyle choices, this figure is slightly higher than for a
woman who is married to a man who by smoking a pack of cigarettes a day
exposes her to his second-hand smoke, or than somebody who doesn’t like
vegetables (whose cancer risk is 1.061 times higher than people who eat
vegetables).
The range 100 to 200 mSv is a high dose of radiation; it is what people
working at the Fukushima Daiichi Nuclear Power Plant are exposed to. But
eating too much salty food or becoming too fat carries the same kind of
risk of cancer. Smoking increases cancer risk by more than 10 times that,
and second-hand smoke has a similar effect to being exposed to 100 mSv
of radiation. (I conclude from these figures that we need to take measures
against second-hand smoke as soon as possible.)
Seen in the light of these comparisons, exposure to radiation from the
nuclear accident is an insidious cancer risk indeed, but there are many things
in our everyday lives that, though we tend not to notice them, nonetheless
appreciably increase our risks of cancer. These things should not be
overlooked, either.
With the nuclear accident and exposure to radiation leaks caused by this
accident, we are faced with threats that we have never experienced before,
4342
and we are likely to blame radiation for all our worries and insecurity. It is
natural to do this. However, as a cancer specialist I feel it is my duty to warn
you that making bad lifestyle choices -- drinking and smoking more and
eating fewer vegetables -- out of one’s fear of radiation exposure may in
the end increase your risk of cancer. Unfortunately, the Chernobyl nuclear
accident has proven that this can happen. I will explain this in detail in
Chapter 4.
Chapter 3The Truth About Hiroshima and Nagasaki
(1) What the Data From Hiroshima and Nagasaki Tell Us
Valuable Records, a Legacy to Posterity
Myriad lives were lost irreplaceably in the atomic bombings of Hiroshima and
Nagasaki, events which have marked people’s hearts around the world as the
most ghastly massacre in the history of mankind.
As ghastly as it was, the atomic bombing victims’ unprecedented ordeal has
provided a huge wealth of data for research on the effects of radiation on the
human body. The experiences of Hiroshima and Nagasaki have undoubtedly
laid the foundations of current radiology and radiation therapy research. The
dropping of the atom bombs on Hiroshima and Nagasaki has also provided
themes for such great works of literature as Masuji Ibuse’s Black Rain and
Tamiki Hara’s Summer Flowers, a literary legacy for future generations.
While the war experience itself seems increasingly to have been forgotten,
we Japanese must never allow ourselves to forget the atomic bombings of
Hiroshima and Nagasaki.
Decisive Factors in Radiation Dose
The radiation dose one would receive from an atomic bombing is decided
almost entirely by how far away the person is from the hypocenter or ground
zero. In the case of Hiroshima, large amounts of gamma rays and neutron
radiation were released from the atomic bomb that exploded 600 meters
above the ground, instantaneously killing nearly 100,000 people due to
external exposure to radiation. These deaths were caused by acute radiation
damage. Since radiation spreads much more quickly than conventional blast
waves and infrared (heat) rays, many people were exposed to large amounts
of radiation in about one millionth of a second. There was absolutely no time
for them to run away.
The amount of exposure for those who were at ground zero is estimated to
have been roughly 100 sieverts (Sv), equivalent to 100,000 mSv, of gamma
rays and 140 Sv of neutron radiation. However, the greater the distance from
ground zero, the smaller the amount of radiation: at 500 meters from ground
zero, the amount of exposure was 28 Sv for gamma rays and 31.5 Sv of
neutron radiation. People 3.25 km away were exposed to 1.0 mSv. With each
4544
further increase of 200 meters in the distance from ground zero, the amount
of exposure is halved.
The Health Status of Atom Bomb Survivors
In 1972, Hiroshima University’s Research Institute for Radiation Biology and
Medicine began a study on 78 people who found themselves within 500 m
of ground zero but miraculously survived. It is thought that these people
were exposed to lesser doses because they were in concrete buildings,
underground, or in packed streetcars and that these obstacles blocked
the radiation. Their survival was presumably due to the sheltering effect of
buildings and to their distance from ground zero.
In other words, at Hiroshima and Nagasaki, the amount of exposure was
decided by where that person was at that instant. Through interviews
and medical examinations of survivors, the detailed relationship between
amounts of exposure and cancer has been documented; survivors’
experiences have provided us with valuable scientific data.
Contrastingly, an accident at a nuclear power plant is different in this regard:
radioactive substances are carried by wind, are dissolved in the rain, and seep
into the soil, and the amount of radiation differs significantly depending on
the location. For this reason, the amount of residents’ exposure cannot be
accurately determined without a portable dosimeter.
Given these limitations, the data from the atomic bomb survivors are
the most reliable we have. Data from Hiroshima and Nagasaki prove that
exposure to over 100 mSv of radiation causes a linear (directly proportional)
increase in cancer.
It should be pointed out that in addition to the initial burst of radiation,
there were radioactive substances that fell from the sky later (“fallout”) and
additionally exposed some people in Hiroshima and Nagasaki after the atom
bombs were dropped. People exposed to radiation days after the explosions
are called post-blast radioactivity survivors; compared to survivors of the
initial radiation, these people were exposed only to very small amounts of
radiation.
Overview of the Atomic Bomb Damage
Let me give you an overview of the damage caused by the atomic bombs. Of
the 340,000 to 350,000 people living in the city of Hiroshima, between 90,000
and 166,000 people died within four months of the bombing due to the
destruction of nuclear blast winds, heat rays, and radiation. In Nagasaki, of the
250,000 to 270,000 population, 60,000 to 80,000 people died.
However, these numbers of deaths are just estimates, since records of deaths
of military personnel were destroyed by fire and some entire families were
killed, leaving nobody to report the deaths. A number of U.S. prisoners of war
also died in the atomic bombings.
We think that a breakdown of the total energy from an atomic bomb is 50%
blast winds, 35% heat rays, and 15% radiation. Of the total number (100%)
of those killed by the blasts within 2 km of ground zero, 88.7% died within
the first two weeks and 11.3% died from the third to the eighth week. The
breakdown of causes of death for those within 1.2 km of ground zero is
roughly 20% external wounds from blast winds, 20% damage from radiation,
and 60% due to heat rays, secondary fires, and burns.
Cancer and leukemia (like trauma and burns) occurred later, and more
frequently, the closer to ground zero the victims were at the time of the blast.
It is believed that roughly half of the deaths caused by leukemia and roughly
10% of solid tumor cancer cases were caused by exposure to radiation. The
total number of cancer cases that resulted from exposure to radiation is
estimated to be roughly 1,900 cases as of the year 2000.
Keloids Are Not Caused by Radiation
Most of the people who died in the atomic bombings were killed directly
after the explosion by the blast winds and heat rays. The temperature at
ground zero was over 3,000 degrees Celsius; many people died from whole-
body burns.
Half of any group of people whose whole body is exposed to 4 Sv (4,000
mSv) of radiation die. However, even in this kind of massive exposure, the
temperature of that person’s skin rises by only 1/1000. The burns and keloids
caused by the atomic bombings have nothing to do with radiation, though
they are the main cause of many of the victims’ deaths. This fact may not be
as widely known as one would expect.
4746
The Story Told by the Hiroshima and Nagasaki Data
The following effects of radiation on the human body have been
documented.
Ten years after exposure, there was an increase in breast cancer, gastric
cancer, colorectal cancer, lung cancer, and other types of cancer. It was
established from these and other data that the risk of cancer increases with
exposure to more than 100 mSv of radiation.
Leukemia began to increase about two years after exposure, and its incidence
in children increased several-fold. We found out from this that children are
affected more easily than adults are by radiation. After six to eight years, the
number of patients with leukemia started to decrease, and after twenty years,
leukemia rates were back to the Japanese average.
It should be noted that no genetic effect of radiation exposure has been
found to be passed down from survivor parents to their children (so-called
“second-generation survivors”). Though genetic effects have been observed
in studies conducted on animals, no genetic effect of exposure to radiation
has been confirmed in humans.
There are, however, things that we do not yet understand. For example, we
do not know whether or not cancer rates increase after exposures of less than
100 mSv -- an issue currently in dispute in the wake of the nuclear accident.
I wrote about this in Chapter 1, but there is no scientifically confirmed
increase in cancer at exposures to radiation under 100 mSv. In other words,
there is scientific data for exposures over 100 mSv, but no data for exposures
under that level. This means that even if there is a risk, it is too small to detect.
The Black Rain That Fell on Hiroshima and Nagasaki
Masuji Ibuse’s novel Black Rain tells the tragic tale of a woman who, although
she escaped the radiation and heat rays that were emitted after the atomic
bomb’s flash and explosion, was exposed to radioactive substances in the
rain that fell far from ground zero. The atomic bombs dropped on Hiroshima
and Nagasaki exploded in the air, 600 m and 503 m above ground level
respectively. The explosions became huge balls of fire that were pushed
upwards into the sky by ascending air currents. It is believed that roughly
10% of the nuclear material in the bombs caused fission reactions emitting
large amounts of energy called radiation. The remaining 90% is believed to
have risen into the stratosphere along with the fireball.
Some part of these radioactive substances (uranium in Hiroshima and
plutonium in Nagasaki) fell on the cities of Hiroshima and Nagasaki as black
rain. Radioactive substances are carried considerable distances by the wind.
In Hiroshima the winds drifted north-westward, and the rain containing
radioactive substances fell on north-western regions of Koi and Takasu; in
Nagasaki they rode the winds eastward in the direction of the Nishiyama
district.
Ground contamination due to falling radioactive substances (fallout) was
actually higher in distant regions. However, it has been confirmed that the
residents in these far away areas have been exposed only to small doses of
radiation. The level of exposure due to ground contamination at ground
zero was roughly one-tenth that of those distant locations with the highest
levels of contamination. This is similar to how there are locations with low
levels of contamination close to the Fukushima nuclear reactor, while hot
spots recording high levels of radiation are found far away from any nuclear
reactors.
Some part of the radioactive substances made its way into rainwater and fell
to earth; it is believed that the greater part of the uranium and plutonium
from the blasts was dispersed widely in the atmosphere. The half-life of
Uranium-235, for example, is 700 million years. If there were much of this left
in the city of Hiroshima currently, the risk of exposure to radiation would still
be high. In neither Hiroshima nor Nagasaki is this the case, however.
In sum, the effect of radioactive fallout from the two first atomic bombs has
become so small it cannot be distinguished from the nuclear testing that
took place in the atmosphere in many parts of the world during the 1950s
and 1960s.
4948
(2) Another Chapter in the True Story of the Atom-Bombed Cities
The Health Status of Post-Blast Radioactivity Survivors
People who entered the cities of Hiroshima and Nagasaki the day after these
cities were bombed were also exposed to radiation. These are “post-blast
radioactivity survivors” who entered a 2 km radius of ground zero within two
weeks after the atomic bombings. They entered the city looking for relatives
and acquaintances, or happened to be outside the city the day it was
bombed but less than two weeks later returned or entered the city for relief
efforts. These people were exposed to fallout and “induced radiation” from
the atomic bombs. (Neutron radiation emitted by atomic bombs hits other
materials and makes them radioactive; the radiation from those materials is
called induced radiation.)
However, very surprisingly, the average life expectancy of post-blast
radioactivity survivors is higher than that of the average Japanese. In addition,
the average life expectancy for women in Hiroshima is the highest in Japan
(and the longest life expectancy in Japan’s cities of over 500,000 population).
How can this be?
Since the Japanese have the highest life expectancy in the world, that would
mean that women in Hiroshima have the world’s highest life expectancy. Not
only that, but the birth rate is number two, and the rate of stillbirths is second
from the lowest in Japan. The city of Hiroshima underwent a miraculous post-
war recovery, and has become the number one industrial city in western
Japan, with a population of currently 1.2 million people. What can explain
this?
Why is Hiroshima Women’s Life Expectancy the World’s Highest?
What brought about Hiroshima women’s unexpectedly high life expectancy?
It seems the atomic bombings and tragedy of the people of Hiroshima had
an ironic outcome.
This owes much, firstly, to the “Survivor’s Handbook” (officially called the
Atomic Bombing Survivor’s Health Handbook). These official certifications
entitling their bearers to free health care were delivered to those who were
directly exposed to radiation at Hiroshima or Nagasaki or in adjacent areas
when these cities were atom bombed, to those who entered within a 2 km
radius of ground zero within two weeks after the bombs were dropped (post-
blast radioactivity survivors), and to those who were still in the womb of their
mother when she was exposed to radiation at the time of the bombings.
Holders of a survivor’s handbook can, in principle, receive treatment at any
hospital, free of charge, not only for cancer, but also for diseases ranging from
diabetes to the common cold. Currently around 220,000 people have these
handbooks. Their number peaked in 1980 at 372,264. This is a number larger
than the combined populations of the cities of Hiroshima and Nagasaki at the
time the war ended.
Free medical treatment had tremendous effects. In particular, in the case of
post-blast radioactivity survivors who were exposed to lower amounts of
radiation than the blast survivors (i.e. survivors who entered the cities after
the cities were atom bombed), the positive effects of enhanced access to
medical care were greater than the negative effects of exposure to radiation,
and these survivors ended up living longer than the national average.
We can say that Hiroshima demonstrates vividly to us what good healthcare
can do for a population.
There is one additional factor in their longevity that I want to mention: the
fact that residents didn’t evacuate after the atomic bombings, but continued
to live where they had been, played a part.
I do not even want to think about, but I have to ask myself: what would
happen if Tokyo were to be atom bombed? I fear that many of the survivors
would “evacuate” immediately, fearing black rain and residual exposure, and
this would have dire consequences. However, at the end of World War II, only
a small number of experts had any knowledge of radiation, so the people of
Hiroshima and Nagasaki did not realize that radiation was dangerous or fear
it in the aftermath of the bombings.
This, then, is another reason why there were so many unknowing post-blast
radioactivity survivors: those who survived stayed where they were and
did not evacuate. No one lived in uncomfortable refugee housing because
they were afraid of radiation -- presumably because they were ignorant of
radiation’s dangers.
5150
In Chernobyl, on the other hand, the average life expectancy dropped
significantly. I will write about this in the next chapter.
The Worst Nuclear Accident in History
In the long history of the development of nuclear power, the nuclear accident
that occurred in Chernobyl (in the former Soviet Union, now the Russian
Federation) on April 26, 1986, is considered to be the worst ever.
When workers tried to shut down Unit 4, considered to be state-of-the-art
equipment at the time, for periodic maintenance, the reactor went out of
control and blew up.
Radioactive substances such as cesium and iodine spread across a wide area,
contaminating Russia, Ukraine, and Belarus. The radioactive substances it
generated wound up causing serious problems in Sweden and Finland as
well. The radioactive substances released were equivalent to 400 bombs of
the type dropped on Hiroshima.
The government of the USSR at the time made the damage caused by the
accident worse by initially refusing to admit that an accident had taken
place and failing even to take the barest minimum of precautions, such
as restricting the supply and intake of contaminated food and milk. I will
explain this later, but the frequent occurrence of thyroid cancer in children
was in part caused by the careless response of the government. In addition,
unnecessarily stringent evacuation measures, taken after the USSR collapsed,
were an additional major aggravating factor that shortened former residents’
lives.
The Actual Number of Victims
Those killed by the accident were workers at the plant and firefighters who
came in to extinguish the fires immediately after the explosion. Of these 134
people who threw themselves into this suicide mission, exposing themselves
to 1,000 to 8,000 mSv of radiation, 28 died within three months of the
accident due to acute radiation. Roughly 20 more of the remaining workers
and firemen died within 25 years of the accident. Cancer seemed to be the
cause in some, others died of heart disease, and some died in other accidents.
There were various causes, but the specific cause of death has been identified
for each of them.
Chapter 4The Truth About the Chernobyl Nuclear Accident
5352
Apart from the 48 I have mentioned, all the rest are still alive as of this
printing. Therefore, out of 134 people exposed to intense radiation, the
deaths of 48 were directly caused by the nuclear accident.
According to Russian scientists specializing in nuclear energy, records are
being kept even now on 500,000 people, including both workers involved in
post-accident management and cleanup (who worked within a 30 km radius
of the nuclear power plant but not including the above-mentioned 134
who took part in the suicide mission) and civilians; of this large monitored
group, 198 died due to leukemia within 25 years of the accident. If you are
wondering if all of these 198 leukemia cases were due to the effects of the
accident, they are not. Leukemia, also known as cancer of the white blood
cells, also occurs in people leading ordinary normal lives. Of these 198 deaths
due to leukemia, 80 deaths are thought to be due to exposure to radiation
from the accident. These do not include the civilians, only the workers whose
work within a 30 km radius of the nuclear power plant was connected with
the accident.
The Increase in Thyroid Cancer in Children
So what exactly was the effect on the general public?
There were fears that there would be an increase in various other kinds of
cancer, but the only increase reported was in thyroid cancer in children. The
cause of thyroid cancer is radioactive iodine. Because the nuclear reactors
in Chernobyl were made of graphite, much of this graphite caught fire due
to the explosion. The pillar of smoke containing graphite rose 1.5 km in the
sky. That smoke contained radioactive substances such as iodine, and high
concentrations of iodine were even detected in locations 250 km away from
the nuclear power plant.
Iodine is a volatile substance, and can be carried in the wind to far away
locations once it is released into the atmosphere. If it drifts into parts of the
sky where it is raining, it will dissolve in the water and fall to the ground. This
is the reason iodine was detected in metropolitan areas far away from the
Fukushima nuclear power plant after its accident.
There were 5,000 children (as of 2006) who were diagnosed with thyroid
cancer due to exposure to iodine scattered across a vast geographical area
by the Chernobyl accident; 9 of these children died. In the 25 years since
the accident (as of 2011), roughly 6,000 people have been operated for
cancer, and 15 of these people have died. The survival rate at five years after
receiving treatment for thyroid cancer is 95% or better: this is an example of a
“curable” cancer.
Was There a Sudden Increase in Bladder Cancer?
There are often claims that bladder cancer increased suddenly after
Chernobyl, since radioactive substances were detected in the urine of those
exposed, but these claims have no basis from a scientific point of view.
There are also claims that there were infants born with hydrocephalus and
abnormally large heads. Though some scientists claim that some form of
inherited symptoms occur in children born to parents who were exposed to
radiation, there is no evidence that exposure to radiation has an effect on
future generations, and the studies conducted at Hiroshima and Nagasaki
concur. In fact, reports from credible international organizations such as
the United Nations Scientific Committee on the Effects of Atomic Radiation
(UNSCEAR), the International Atomic Energy Agency (IAEA), and the
International Commission on Radiological Protection (ICRP) state that genetic
effects are not seen.
Scary and dangerous mental images are associated with radiation and
radioactivity in Russia and elsewhere. The same is true in Europe. There
are some people in Europe who claim that 100,000 people died due to the
accident at Chernobyl and the government has covered this up. However, it
is internationally agreed that the only health effects on civilians due to the
Chernobyl accident were an increase in thyroid cancer for children.
The Reason Thyroid Cancer in Children Could Not Be Prevented
Cesium and a variety of other radioactive substances are certain to have
been scattered in the environment in Chernobyl when the nuclear reactor
exploded, but why did only the iodine induce thyroid cancer?
Even scientists and experts who conducted on-site health surveys did not
initially know the reason for this, because there was no hint in the data
collected in Hiroshima and Nagasaki that iodine was the culprit. Scientists
then studied the frequency of thyroid cancer in those who were children at
the time of the accident and those born after the accident. They found that
thyroid cancer was concentrated in children who were 0 to 5 years of age at
5554
the time of the accident, and no increase was detected in children who were
then still in their mothers’ wombs.
Let us use the process of elimination to find the culprit. Cesium also was
released along with iodine due to the explosion. Since cesium has a long half-
life of 30 years, there should have been an effect on children born after the
accident. However, there is no increase in cancer in children born after the
accident. Thus cesium is crossed off our list of suspects.
On the other hand, iodine has a short half-life: eight days. It will affect those
who take in iodine immediately after the accident, but it will not affect
children born some time after the accident.
To start with, iodine is a substance that is easily taken up by the thyroid
gland. It gets absorbed in the thyroid gland and becomes the raw material
for creating thyroid hormones. Whether or not it is radioactive, the substance
iodine has the same properties, so the thyroid gland will absorb radioactive
iodine as well.
Having marked iodine as a suspect, scientists found out when they studied
iodine’s pathways into a child’s body that thyroid cancer occurred at
higher rates in children who drank lots of milk. As a result, the mechanism
responsible for causing thyroid cancer was identified as the drinking of milk
contaminated with high levels of iodine. There were no restrictions on milk
and food consumption in Chernobyl of the kind that were put in place for
Fukushima, so there was no way to prevent exposure to radiation through
food. (It was impossible to expect countermeasures to be taken when the
accident itself was being concealed.)
Thus children drank their contaminated milk, suspecting nothing. Children
drink more milk than adults, and are at a higher risk of developing cancer
than adults when exposed to the same amount of radiation.
The Complete Food Chain Leading to Cancer
Chernobyl being inland was another factor. Iodine is an element that is
essential to the human body. Japan is surrounded by the ocean, so seaweed,
which is rich in iodine, is in the diet. The Japanese take in iodine everyday, but
this is not the case for people living in the central regions of a vast continent.
It is not uncommon for people to develop chronic iodine deficiency diseases
such as hypothyroidism when they cannot take in enough iodine from
sources such as seaweed. In the US, they add iodine to table salt (“iodized
salt”) in order to prevent this.
In short, becoming iodine deficient is always possible unless you do
something about it. In the area around Chernobyl, the local food contains
very little iodine. If iodine suddenly appears in this kind of environment, even
when it is due to a nuclear accident, our bodies will thirstily absorb the iodine
in the way a thirsty person drinks water. Dairy cows ate grass contaminated
with radioactive iodine, and people drank milk from these cows that had
accumulated high concentrations of iodine. This is the food chain that led to
cancer.
Why Iodine Collects in the Thyroid Gland
How does the iodine absorbed by the thyroid gland cause cancer?
Before answering this question, let us think of why the thyroid gland takes in
iodine. Why instead of circulating throughout the body does it accumulate
in just one organ? Most cells in the human body do not need iodine. Only
cells in the thyroid gland need iodine, because it uses iodine to make thyroid
hormones. These hormones promote cell metabolism and can be likened to
the accelerator in a car.
It is indispensable to life in vertebrates from fish upwards on the evolutionary
trail to mankind and would be easier to vaguely understand when likened to
the driving force behind a tadpole’s transformation into a frog.
Cells in the thyroid gland need three or four iodine atoms to create one
molecule of hormone. It is for this reason that cells in the thyroid gland
take in iodine and have the ability to store it. Cells in the thyroid gland do
not, however, have the ability to determine whether or not that iodine is
radioactive. Radioactive iodine taken in by the thyroid gland emits beta
rays, which have a range of just a few millimeters. This is why radiation only
damages cells in the thyroid gland; other organs are out of its range. This is
why iodine only causes thyroid cancer.
Thyroid Cancer’s Real Danger to Children
This is important, so I will state it once again: the only health hazard that has
been confirmed to affect residents of Chernobyl is thyroid cancer in children.
5756
Children were affected because rain that had radioactive iodine (Iodine-131)
in it fell on grass, which was eaten by cows, which produced milk with high
levels of radioactive iodine. The former Soviet government did not announce
the Chernobyl accident for several days and was slow to place restrictions on
food products. The children of Chernobyl, located inland, were chronically
iodine deficient. Radioactive iodine released from the nuclear reactor
suddenly became abundantly available to their thyroid glands. The substance
itself is the same, whether or not it is radioactive, so these children’s thyroid
glands took in enormous amounts of radioactive iodine. As a result, in this
region almost 1% of children under the age of four had their thyroid gland
exposed to more than 10 Sv (10,000 mSv) of radiation. Growing children’s cells
divide very actively, making their genes more easily affected by radiation,
creating the conditions for cancer to get a start more easily in them. This is
why thyroid cancer in children increased.
Radioactive Iodine Is Also Sometimes Used to Treat Cancer
On the other hand, iodine, even radioactive iodine, is not a substance that
does only bad things. Radioisotope therapy uses the unique property of cells
in the thyroid gland to induce the gland to take in iodine (if you remember,
other cells do not...) in order to treat cancer.
Although it seems like this treatment would be difficult, it is actually very
simple. Radioactive iodine is placed in small capsules, which the patient
swallows. Let us say that there are cancer cells in the thyroid gland for some
reason. Since cancer cells originally are created through a mistake in copying
ordinary cells, they inherit the characteristics of the organ they were born in.
As a result, the administered iodine accumulates inside thyroid cancer cells.
This is a mechanism that kills even tough cancer cells, since just like normal
cells they have little ability to mend the damage caused by radiation.
However, the patients -- in Japan -- are asked to refrain from taking in
seaweed and other foods rich in iodine before they take the radioactive
iodine capsules. This is to “starve” the thyroid cancer cells of iodine.
Conversely, in other cases, leaving the thyroid gland “sated” or filled with
as much iodine as it can absorb is a method of preventing damage from
environmental radioactive iodine. If the thyroid gland is sated with iodine
that is not radioactive, there is no place for new radioactive iodine to settle
even if it gets into the body, and eventually it will make its way out of the
body. This is called thyroid blocking, and is the reason why (non-radioactive)
potassium iodide is distributed to nearby residents in case an accident occurs
at a nuclear power plant.
But be careful: you need to know more. Recently in Fukushima, this became
an issue because it is dangerous to drink tincture of iodine just because it has
iodine in it. This may actually cause worse health effects than radiation.
In emergencies, iodine is distributed to people by local governments. It is not
something sold at drugstores. If you were given this in an emergency, you
would be told to take 100 milligrams per dose for adults, 50 mg for children.
But it may cause side effects, so please always follow the instructions of your
healthcare provider.
Supplements and quack remedies are advertised “to cleanse the body and rid
it of radiation”; these products sell well whenever people feel anxious in the
event of emergencies. From a doctor’s standpoint, I think it would be wise to
stay away from them.
And finally, given what we know about the levels of thyroid exposure to
radiation from the Fukushima accident, there is simply no need to take iodine. The Differences Between Chernobyl and Fukushima
The nuclear accident at Fukushima and Chernobyl were both rated Level 7 in
severity on the International Nuclear Event Scale.
Though Chernobyl and Fukushima are often compared to each other, there is
one major difference: at Chernobyl, a nuclear reactor blew up while it was in
operation, releasing all sorts of radioactive substances. At Fukushima Daiichi,
the nuclear reactor and the containment vessel surrounding it remained; it
was the reactor building housing the containment vessel that was damaged
by a hydrogen gas (not a nuclear) explosion.
Here the explanation becomes a bit technical, but nuclear power plants in
Japan are designed to trap the fuel that produces energy through nuclear
fission in the reactor, surround that with a containment vessel, and cover
that further with a reactor building. There was no containment vessel around
the Chernobyl reactor, and one safeguard designed to confine the nuclear
reactor that blew up did not function. At Chernobyl, restrictions on milk and
5958
other food items were put in place too late, exposing many children’s thyroid
gland to enormous amounts of radiation (10 Sv, or 10,000 mSv).
In Fukushima however, evacuation measures and restrictions on milk and
food were put in place right away. Therefore, the risk of damage and injury
from iodine with its short eight-day half-life, where an immediate response is
required, was kept to a minimum. Measurements of thyroid exposure in over
1,000 children in Fukushima show that the maximum level of exposure was
35 mSv.
The level of exposure at Chernobyl was three levels of magnitude (a thousand
times) higher, and thyroid exposures under 50 mSv do not increase cancer
rates. Therefore, we can say with some certainty that thyroid cancer rates will
not increase in Fukushima. Exposure to radioactive iodine almost exclusively
affects the thyroid gland, but the amount of whole-body exposure to
cesium in Chernobyl was more than 50 mSv for the 270,000 people in highly
contaminated areas, and from 10 mSv to 20 mSv for the 5,000,000 people in
low-contamination areas. However, even now, 25 years later, cancer due to
cesium has not been confirmed.
As I will report in the next chapter, there is far less exposure to cesium in
Fukushima, so it is safe to say that there will be no increase in any kind of
cancer.
Restrictions on Food Products Came Too Late in Chernobyl.
In Chernobyl, initially the very occurrence of the accident was concealed; no
planned evacuation took place, nor were restrictions placed on the supply
or intake of food products and milk that were contaminated with radioactive
substances. Residents went on with their daily lives as if nothing had
happened, even in places that should have been evacuated. The accident
occurred on April 26th, but on May 1st (May Day, or International Workers’
Day, a public holiday in the Soviet Union) many people were marching in
parades while radioactive materials were being released into the atmosphere
not far away. The government had announced that food was safe to eat, and
people in villages continued to eat their accustomed food and to live their
usual lives.
In Fukushima on the other hand, immediately after the accident, restrictions
were placed on the intake of food and milk in which radioactive substances
had been detected in amounts in excess of Japan’s regulatory limits. I believe
that the problem of contaminated milk that occurred in Chernobyl could
have been avoided in this way.
Japanese Food Regulations Are Safe
Japanese regulations on food are very strict. There is normally no need to eat
food that exceeds regulatory limits, but the exposure would not be enough
to affect a person’s health, even if some were ingested.
For example, at the Kanamachi water treatment plant in Tokyo, the water’s
radioactivity at one time measured 210 becquerels per kg, which exceeded
the limit set for water given to infants (100 becquerels per kg).
There is no need to go out of your way to drink this, but even if infants drank
a little, or if milk was reconstituted with this water, there would be no effect.
A person would have to drink one metric ton of this water for there to be any
effect. Realistically speaking, there is no way that a person can continuously
drink one metric ton of water whose level exceeds the restrictions.
Not only that, but the safety standards for radioactivity in food that would
cause internal exposure to cesium are even stricter. Yoko Komiyama, Minister
of Health, Labour and Welfare, announced on October 28, 2011, that she
would lower temporarily the upper limit for radioactive cesium from 5 mSv
per year to 1 mSv per year. She did this because the Food Products Safety
Commission of the Cabinet Office released a report stating that effects
of radiation on people’s health had been found in people exposed to a
cumulative amount of more than 100 mSv in their lifetime.
I participated in the Food Safety Commission’s discussion as an expert
witness. The thinking is like this: if we assume people may live until they are
100 years old, the upper limit to exposure from food would be 1 mSv per
year. For example, the temporary regulatory limit for vegetables is 500 mSv
per kg, but if this were simply divided by five, the upper limit would be 100
mSv. This is only 1/12 that of the limit in the United States, and an extremely
tough target for producers to achieve. However, this revised, more stringent,
standard should lessen fears of internal exposure and bring peace of mind to
a larger proportion of the population.
6160
Problems With Defining the Evacuation Zone in Fukushima
I can say good things about the restrictions placed on food, but problems
remain with the evacuation measures taken. The orthodox approach to
protecting the public from radiation is by establishing evacuation areas
within 20 km or say 30 km of a nuclear power plant.
Until the Fukushima accident, related organizations’ training for emergencies
in nuclear power plants defined the evacuation area as within a 10 km radius
of the accident site. It would appear that following the accident, authorities
have assumed that doubling the radius of the perimeter to 20 km would be
better.
However, there are locations beyond the evacuation zone perimeter where
high levels of radiation were recorded. Like pollen, radioactive substances can
reach locations far away from the nuclear power plant, wherever the wind
carries them, and high levels of radiation will be detected there. In fact, it was
learned from the Chernobyl experience that wind direction and other factors
are crucial. This point appears to have been overlooked in the confusion
caused by a nuclear accident following on the heels of the unprecedented
major earthquake and tsunami catastrophe affecting a vast geographical
area. This is a situation that we must all think seriously about and attempt to
learn from.
Average Life Expectancy Fell After Chernobyl
I stated in the previous chapter that women in Hiroshima have the highest life
expectancy in Japan. Average life expectancy in Russia and Belarus, however,
significantly decreased after Chernobyl. The average life expectancy in Russia
in 1986 when the accident happened was 65 years; this fell seven years, to
58, in the year 1994. The same very significant decrease was seen in Ukraine
and Belarus as well. The National Academy of Sciences of Ukraine has offered
an analysis revealing that the death rate of elderly people rose particularly
steeply.
Roughly 50 of the firemen and workers who entered the nuclear power
plant on their heroic mission to bring the accident under control, 80 people
who took part in accident control and cleanup efforts who later developed
leukemia, and 15 out of 6,000 in the general population who developed
thyroid cancer are thought to have died as a result of exposure to radiation.
Other than thyroid cancer, there are no confirmed pathological changes
in the general population of civilians that are thought to be caused by
radiation exposure. These death tolls are not enough to affect the average life
expectancy of a country.
I believe that the real reason why life expectancy was shortened was many
people’s grief at the accident and their weakened will to live. The people
in Chernobyl must have known how scary radiation is, having heard about
Hiroshima and Nagasaki, so presumably they have been tormented by
anxiety and fear. Even experts and doctors who flew in from the United States
and Europe brought their own food and water and did not touch the local
food products. People had to live away from home and in fear of developing
cancer, and many had lost their jobs. No one would buy the farmers’ crops,
job opportunities disappeared, and a steady exodus of people began.
The Soviet government, on which people ought to have relied, was destined
to collapse five years later: it was not a situation in which one could expect
generous support. People lost their pride and reason to remain alive and were
economically stymied as well. There were people who became dependent
on alcohol out of desperation, others who suffered severe and lasting
depression, and some who went as far as to commit suicide. The death rate
for elderly males was high in Ukraine, and this is probably because males are
especially vulnerable to this kind of psychological damage.
What Unnecessary Evacuation Really Does
As I stated in the previous chapter, after the atomic bombs were dropped,
the people of Hiroshima lived long lives; after Chernobyl, the average life
expectancy dropped significantly.
In the case of Hiroshima, good medical care and the issuance of atomic bomb
survivor handbooks had good effects that were strong enough to overcome
the adverse effects of exposure to radiation, but in Chernobyl, evacuation
(which did not happen in Hiroshima) did more harm than good.
In the case of Chernobyl, all residents of areas where annual exposure would
amount to or exceed 5 mSv were forced to evacuate. This figure 5 mSv is a
low level, four times as strict as the 20 mSv per year limitations placed on the
planned evacuation zone in Fukushima.
6362
The official report issued in 2011 by the Russian government, “25 Years
After the Chernobyl Accident: Summary and Overview of its Impact and
Overcoming the After-Effects 1986-2011”, expresses the following regrets
over “excessive evacuations”:
“What aggravated severalfold the social, economic, and psychological
consequences of the Chernobyl accident was to a large degree the
legislation that defined ‘contaminated areas’ more strictly than
necessary.”
The same report also addresses the negative impacts that evacuation has on
people:
“It was revealed that the side-effects of the accident such as psychological stress, the destruction of the way of life people had become accustomed to, and restrictions on economic activities were far more damaging than the exposure to radiation.”
There was an increase in thyroid cancer in children because no restrictions
had been put on milk and food, but there has been no confirmed increase in
any other type of cancer. And yet the average life expectancy in Ukraine and
Belarus fell by roughly seven years after the accident at the nuclear power
plant.
The report concludes: “There is one main lesson from the nuclear accident at
Chernobyl, which is that the importance of social and psychological factors
was not fully appreciated”.
Depending on the kind of evacuation, evacuation itself may shorten a
person’s life, even if it reduces the evacuee’s exposure to radiation. The
loneliness of living in an unfamiliar place, economic stress due to joblessness,
and living in fear of developing cancer due to radiation -- there is simply no
way that this kind of life is good for one’s health.
In fact, it has been scientifically proven that lifespan can change greatly
due to the social and psychological factors referred to in the Russian
government’s report. For example, lifespan varies depending on occupation.
In data from British males, unskilled workers live an average of seven years
shorter lives than those who work in a profession. Japanese data show that
males with low incomes have twice the risk of dying from cancer than those
with high incomes. The average life expectancy in Nishinari, Osaka, where
there are many homeless people, is the lowest in Japan, for example.
On the other hand, let us think about how much a lifespan can be cut short
due to exposure to radiation. The 6.4 million residents in the contaminated
area in Chernobyl were exposed to roughly 10 mSv of radiation.
As I mentioned in Chapter 1, there are no data to suggest that less than
100 mSv of exposure to radiation increases cancer rates. The linear no-
threshold model, which assumes merely on a precautionary basis that
cancer can increase with even a slight increase in exposure, has become
the basic concept for protection against radiation. When calculating the
effect on the average life expectancy of today’s Japanese citizens based
on this model, we find that 10 mSv of exposure would shorten average life
expectancy by roughly 4 or 5 days. We see that the effect is far less than the
negative consequences of evacuation. Even the International Commission
on Radiological Protection (ICRP) -- which advocates the linear no-threshold
model -- has clearly stated in reports that “there is no increase in cancer with
exposure of less than 10 mSv”.
Taking additionally into consideration the fact that residents of countries
formerly part of the Soviet Union don’t have as long a life expectancy as
people in Japan, I conclude that exposure to radiation has little to do with the
observed shortening of Chernobyl residents’ lifespans.
Taking the Lessons of Chernobyl to Heart
We must not repeat the same mistakes in Fukushima. It is for this reason that
medical care for exposure to radiation must be provided together with a
wide range of care in other areas such as attention to people’s psychological
needs.
Nothing can be better than, from the start, having never been exposed to
radiation because of an accident at a nuclear power plant. Let us not forget,
however, that many other risks exist in the world besides radiation. And
what’s worse, people sometimes incur a different and much more serious
risk when they focus too narrowly on only one particular risk. For example,
people who are afraid of airplane accidents may actually increase their risk
of dying in an accident. According to a study conducted by the US National
6564
Transportation Safety Board, the probability world-wide of dying from an
airplane accident is 0.0009%. If this is limited to only domestic US airlines, the
probability is much small lower, at 0.000034%. The probability of dying in an
automobile accident in the United States is 0.03%, so the probability of dying
in an airplane is 1/33 the probability of dying in a car in the US.
And yet, since the synchronized terrorist attacks on September 11, 2011,
many Americans have avoided airplanes and are traveling more by car. For
this reason, the deaths due to automobile accidents in the US between
October and December of that year increased by roughly 1,000 people
compared to the previous year.
The second meeting of a Japanese government working group regarding
response measures following exposure to low-level radiation was held on
November 15, 2011, and there was an intense debate between experts
and Diet members about the effects of the Chernobyl nuclear accident on
people’s health.
From a scientific point of view, experts stated that no confirmable direct
health hazards had been observed in the wake of the Chernobyl accident
other than the increase in thyroid cancer in children. Diet members objected
that the absence of scientific proof is no justification for certainty that no
hazards exist. Some went as far to state that science should show more
humility.
There were also recommendations that the evacuation standards be made
stricter and that exposure limits be set at 5 mSv per year. This annual
exposure of 5 mSv is the standard actually used in the areas around
Chernobyl, and as I mentioned before, the Russian government has stated
in their report that the introduction of these strict standards was politically
motivated -- and that they regret that this resulted in the significant decrease
in average life expectancy of the residents. We can say that there is a need to
think about risks to health and lifespan from a broader perspective.
It is impossible to condone the nuclear accident, but we have no choice but
to go on living in Japan after 3.11. Disparities in informedness also lead to
disparities in health and lifespan. The responsibility of government and media
to inform the public is crucial.
(The following is excerpted from the Conclusion section of the Russian
government’s report, “25 Years After the Chernobyl Accident: Summary and
Overview of its Impact and Overcoming the After-Effects 1986-2011”.)
Conclusion
Currently, 25 years after the Chernobyl nuclear accident, the situation
of radiation hygiene in areas of radioactive contamination has returned
to normal. The amount of additional radiation to which the majority of
residents of areas surrounding Chernobyl are exposed is well within the
range of natural radiation variability in the Russian Federation and many
European countries.
We were able to implement large-scale and complex protective measures
in the contaminated areas in a shortened period of time thanks to Russia’s
scientific capability and expertise in field applications.
This significantly decreased the radiation dose for residents and solved the
following unprecedented and highly complex challenges:
- Trying not to exceed the maximum allowable annual radiation dose for
residents of European countries and the Soviet Union at the time;
- Avoiding significant losses in agriculture and forestry.
It is also important to emphasize that the radiation dose to evacuated
residents is significantly lower than the current reference values for
evacuation.
Although the situation of the nuclear accident was complex, the outcome
was made possible due to the government commission to investigate the
Chernobyl nuclear accident making speedy and clear decisions, the heroism
and self-sacrifice of those who were involved in bringing the accident under
control, and because the workers at reactors number one, two, and three
were able to ensure the security and continuity of operations.
The miscalculations in the first few years of managing the disaster are as
follows:
That prevention of exposure by distributing and administering iodine
was too limited in scale, that no restrictions were placed on agricultural
products and milk which included highly radioactive iodine while it was still
6766
highly radioactive, that the accident response measures put in place at the
site of the nuclear power plant and within a 30 km radius were not always
based on solid evidence, and that in and after 1988 large-scale migration
programs were implemented.
Furthermore, the long-term social, economic, and psychological effects were
multiplied many-fold by the adoption of legislation in the 1990s designating
areas where measured Cesium-137 levels exceeded the reference value of 1
Ci/km2 (37 kBq/m2) as Chernobyl contaminated areas.
This led, however, to the inclusion in the evacuation zone stipulated by law
of areas where the additional radiation impact on residents was lower than
the natural radiation level.
In the social and economic situation at the time, the problem of Chernobyl
was transformed from one of radiation protection for residents into a
political issue.
The social and economic situation in the contaminated area became
extremely difficult due to the psychologically complex situation caused by
the perceptions characteristic of residents with regard to radiation exposure
and its effects on health and the inadequacy of legislative and information
measures.
It is clear now that to ease social tensions in radiation-contaminated areas,
comprehensive information campaigns ought to have been organized to
overcome the effects and after-effects of the radiation accident, to form
a culture of safety in residents’ lives, to secure unrestricted access to
information, and to raise the level of residents’ understanding of radiation.
The documents published in this national report convincingly show above
all that, of the harm to society endured due to the Chernobyl accident, the
effects on health caused by radiation were much smaller than the accident’s
other negative impacts.
From the national registry data on radioactive contamination, we can
confirm that the effects of radiation on people are as follows:
- Of the firemen on the site and the workers at the Chernobyl nuclear
power plant who were there for a full day after the explosion, 134
suffered acute radiation sickness. Of these, 28 died within a few months
after the accident, and an additional 22 died before the end of 2010 due
to various causes;
- Less than 40% of the 748 cases of thyroid cancer in children identified
in Bryansk Oblast, Kaluga Oblast, Orlov District, and Tula Oblast between
1991 and 2008 were caused by radiation;
- Of the 115 cases of thyroid cancer identified in 84,772 people, there
were roughly 20 cases among the “Liquidators” (the teams, numbering
in the thousands, who worked to bring the Chernobyl nuclear accident
under control). The Liquidator group was affected by radiation between
April and July of 1986 while working in the radioactively contaminated
area.
Of the 198 cases registered in the national registry between 1986 and
2007, fewer than 80 people died of leukemia in the Russian Liquidator
group among those who were exposed to more than 150 mSv of
radiation.
Over this 25-year period, 40,000 of the Liquidators (more than 190,000
people) died of various causes.
Chronic ischemic heart disease (1,763 cases) was the most important cause
of death, and malignant tumors (485 cases) in the lungs and bronchi were
the biggest cause of death in patients affected by severe cancer.
The total death rate among the Liquidators does not, however, exceed that
of male residents of Russia.
Furthermore, the mortality rate for residents of Bryansk Oblast (province),
Kaluga Oblast, Orlov District, and Tula Oblast, which suffered the worst
levels of radioactive contamination after the nuclear accident, is close to the
national index level.
The good news is that the infant mortality indices in each of these provinces
has improved greatly in the past several years. This is largely due to the
implementation of a national assistance program for the residents of areas
affected by the Chernobyl nuclear accident. Analysis of the situation 25 years after the accident and comparison of the
6968
effects of radiation with the effects of psychological stress, destruction of
people’s familiar way of life, and restrictions on economic activity makes
it clear that the other factors, namely material losses associated with the
Chernobyl accident, had a far larger detrimental impact on people than
radiation itself.
One of the main lessons learned from the Chernobyl nuclear accident, and
one that can now be asserted openly, is that the importance of social and
psychological factors was not sufficiently appreciated.
No matter what scale at which one examines the data, if an area is
contaminated with radiation, these effects are the most important, and
people’s everyday experiences demonstrate this clearly.
The decisions of authorities must be made based on a comprehensive
assessment of the long-term social and economic outcome of these
decisions, including an analysis of the effects on the psyche of society as a
whole.
Even when the effects of radiation are being lessened in a speedy and
objective manner, a critical worsening of the social and political situation
may occur.
Responses to radiation accidents that are effective and backed by solid
scientific evidence can only be implemented under conditions where the
authorities are trusted and where consistent and fair information policies
are in place.
This means that today’s social responsibility toward people who were
affected by the accident is to compensate the majority of victims for
mistakes made in the past.
This is why social protection needs to continue to be a priority area for the
Chernobyl National Program.
Furthermore, on the national level, a strategic plan backed by scientific
evidence is needed to ensure the social protection of people in each of
different categories who are called on by the state to perform duties
involving health risks. Consideration of the long-term interests not only of individuals but of
society as a whole is the basis of this strategy.
When planning and implementing national policies in this area, we must
consider both provisions of the current legal standards and the following
basic principles and standards which have been validated by actual
experience in the past:
1. To protect the health of citizens who were victims of the disaster and
to secure environmental conditions desirable to live and work in for
residents of the disaster-stricken community are priority areas in the
national government policy for overcoming the adverse health effects and
after-effects of the Chernobyl accident (in the event a state of emergency
has arisen, the protection of residents is of paramount concern, as stated
in Articles 7, 41, and 42 of the Constitution of the Russian Federation).
2. The activities purposefully conducted in coordination with national
government agencies, local government offices, various organizations,
and citizens based on their respective rights, authority, and duties in this
field,
3. Consideration of what social and economic effects they will have, what
resources are needed and sufficient for the purpose, and how they can be
used most effectively in the planning and implementation of policies to
overcome the effects of the Chernobyl accident and in the determination
of the scale and the measures included in these policies.
4. Protection and rehabilitation through medical care for citizens listed in
the national registry. It is the people in this category who need to undergo
medical examinations in the framework of appropriately scheduled
medical services for early disease detection, prevention, treatment, and
rehabilitation.
5. The main criteria when making decisions about the need for measures
to overcome the effects of the Chernobyl accident are the residents’
average annual effective dose and, in cases where the residents of the
area were exposed to doses lower than the predetermined reference
value, the amount of residents’ accumulated exposure.
6. The standards for planning and implementation of measures in the
agro-industry complex and for testing the radioactivity of food and food
7170
ingredients are the health requirements for food and food ingredient
quality and safety.
7. Measures are planned and implemented for social and psychological
rehabilitation in areas where the average annual effective doses of
radiation are lower than the predetermined reference values, and tests
for radioactive contamination in food and food ingredients are done
only when necessary.
It is extremely evident that the implementation of national policies
regarding coping with the nuclear disaster in Chernobyl henceforth must be
conducted within the framework of the Russian Federation’s new objectives
program, “Overcoming Effects of the Accident by 2015”. The items that are
the main objectives for these programs are as follows:
- To achieve levels needed for safe living and economic activities in
communities contaminated with radiation due to the Chernobyl nuclear
accident.
- To strengthen development of response systems that are planned
and technically organized to make it possible to ensure that residents
are protected from all but the fewest possible radiation accidents
and accident effects, based on the experiences of those in charge of
overcoming the effects of the nuclear accident.
The material documented above is consistent with the following:
- The UN action plan regarding recovery efforts in areas around
Chernobyl until 2016 are based on the social and economic development
priorities and resolution, “UN Action Plan on Chernobyl to 2016”,
adopted by the UN General Assembly on November 20, 2007, based on
the Secretary-General’s report on optimizing the international effort to
study, mitigate and minimize the consequences of the Chernobyl disaster
(document A/62/467).
- The Concept of long-term socio-economic development of the Russian
Federation until 2020, approved in Government Decree No. 1662-p of
the Russian Federation on November 17, 2008, includes improving the
quality of the environment and human living environment standards
as well as significantly decreasing the proportion of people living in
undesirable environmental conditions.
Upon consideration of the approach detailed above to overcome future
effects of the Chernobyl nuclear accident, the basic direction of the
national policy in this area must be in accordance with Overcoming the
Consequences of Radiation Accidents for the Period until 2015, a Russian
federal target program, as follows:
- Creating the infrastructure necessary to ensure safe living conditions
for people in the affected areas;
- Development and implementation of integrated measures for the health
of citizens exposed to radiation;
- Creating the conditions for safe use of agricultural land and forestry
“fund” resources (translator’s note: land made available for forestry,
excluding that set aside for defense and similar purposes but including
non-forested land adjacent to forests) in radioactively contaminated
areas;
- Improving radiation monitoring systems and their components, as well
as predicting the evolution of the situation in affected areas;
- Increasing the readiness of authorities and the armed forces to take
action to minimize the consequences of radiation accidents by improving
their technical, technological, normative planning, and organizational
base;
- Information support and socio-psychological rehabilitation of citizens
exposed to radiation;
- International cooperation in overcoming the consequences of the
Chernobyl accident and other radiation accidents.
Implementation of state policy in the aftermath of the Chernobyl nuclear
accident under the federal target program “Overcoming the Consequences
of Radiation Accidents in the Period up to 2015” will make the following
possible:
- Improvement of environmental conditions;
- Restoration of territories affected by radioactive contamination and
restarting of economic activity;
7372
- Ensuring that the most affected populations can lead their daily lives
under safe radiological conditions and protecting their healthcare and
social benefits.
- Providing medical care to persons at greatest risk of negative
consequences of radiation exposure (risk groups);
- Promoting improvement in people’s living standards and quality of life
through the creation of conditions for dynamic and sustainable economic
growth in radioactively contaminated communities; and
- Increasing the willingness of administrative authorities of the Russian
Federation and of the public to meet the challenges of overcoming the
consequences of radiation accidents and incidents.
Lessons learned from the experience of overcoming the consequences and
after-effects of the Chernobyl accident are highly relevant today in light of
the accident that occurred in March 2011 at the Fukushima Daiichi nuclear
power plant in Japan.
(Published by The Ministry of the Russian Federation for Affairs for Civil
Defence, Emergencies and Elimination of Consequences of Natural Disasters,
Moscow, 2011. Source: web site of the Nuclear Safety Institute, Russian
Academy of Sciences <http://www.ibrae.ac.ru/content/view/590/375/>.
Translated from the Russian into Japanese by Fusae Haraguchi. The
underlining is by the authors. Translated from Japanese into English by
Alexander Isao Holmes.)
(1) International Organizations Active on Radiation Exposure-Related Problems
International Rules Regarding Exposures
There are international rules that protect people from radiation exposure.
These rules are decided by the International Commission on Radiological
Protection (ICRP), a British non-profit organization. Governments of every
country follow them.
Perhaps you may have been worried about the effects of radiation from
the Fukushima Daiichi nuclear accident, searched online, and seen
the ICRP recommendations. Many people are alarmed, not only by the
ICRP recommendations, but also by sensational remarks made by other
international organizations regarding radiation and exposure levels and their
risks after accidents at nuclear power plants.
In this chapter I will give a simple introduction to the organizations that make
these recommendations, why Japan and other countries in the world place
importance on and follow the IRCP recommendations, and describe what is
behind the setting of international standards.
United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)
There is a public organization called UNSCEAR, a scientific committee in
the United Nations (UN) that evaluates and reports on the effects of atomic
radiation. Its independence and objectivity are protected, and it is not
swayed by any particular country’s influence or ideology. It reports the effects
of ionizing radiation on the human body from a purely scientific standpoint.
The highly independent UNSCEAR was established by the UN in 1955. During
the Cold War in the 1950s, nuclear tests were repeatedly conducted as the
development of nuclear weapons intensified. The committee was established
out of concern that increasing amounts of radioactive fallout and other
effects of testing would affect the general public. They also make proposals
seeking an end to nuclear tests.
UNSCEAR officially reports that from an epidemiological perspective,
Chapter 5Radiation’s International Standards
7574
radiation doses of less than 100 mSv are too small to allow detection of their
effects.
The International Commission on Radiological Protection (ICRP)
UNSCEAR is a UN organization whose aim is to scientifically evaluate the
effects of radiation on the human body, while the International Commission
on Radiological Protection (ICRP) is a private sector international academic
organization that gives recommendations regarding radiation protection
from the point of view of radiology experts.
The basis of the recommendations made by ICRP is UNSCEAR’s scientific data.
In other words, ICRP recommends policies regarding the risks of exposure to
radiation based on the scientifically proven effects of radiation observed by
UNSCEAR -- which reports, for example, that exposures over 100 mSv increase
risks linearly in proportion to the increase in exposure, while exposures under
100 mSv are not observed epidemiologically to increase such risks.
For example, the ICRP recommendation that the limit for exposure in the
general public should be 1 mSv/year is not based on scientific data. Instead,
it would be more correct to call it a policy approach that takes safety into
consideration.
Let us go back a bit in history. The International X-ray and Radium Protection
Committee (IXRPC), ICRP’s international organizational predecessor, was
founded in 1928. This organization’s origins go back to the discovery of X-rays
by Wilhelm Konrad Röntgen in 1895, and in response to growing concern
about radiation’s effects on the human body with the increase of leukemia
in radiologists and skin disorders in patients that followed rapid advances in
medical radiology after the discovery of radium by Marie and Pierre Curie in
1898.
Events took a huge turn after World War II. Exposures to radiation diversified
with nuclear power plants and nuclear bomb testing in the atmosphere.
In particular, the problem of exposure of the general public in unspecified
numbers arose, something that was never considered to be a problem
before.
This is how, in 1950, ICRP (formerly IXRPC) added nuclear power experts
to the committee along with radiologists and radiation genetics experts,
and started drafting standards for the general public, separate from those
for radiation workers. In this way, we can assume that there was a tug-of-
war over protection and exposure dose limits between those in the nuclear
power industry, who tried to justify a certain level of exposure to radiation,
and radiologists, who are actually on the receiving end of radiation exposure.
It is extremely important to note that, in these efforts spanning many
years, we have been heading in the direction of ever stricter regulations for
radiation doses.
In the first ICRP recommendation in 1958, the limits for annual exposures
for nuclear power plant workers and for the general public were set at 50
mSv and 5 mSv, respectively. After 1977, the limit for the general public was
lowered to 1 mSv. However, ICRP has different staged level recommendations
for “normal”, “emergency”, and “recovery” situations, which I will write about
in detail later.
The Most Reliable Framework Based on International Agreements
What ICRP places the most importance on when issuing recommendations
regarding protection against radiation is the above-mentioned UNSCEAR’s
scientific reports. The IAEA cooperates with the World Health Organization
(WHO) and other international organizations to present international
standards for protection against radiation to member countries based on the
content of the ICRP recommendations.
Japan, like other countries, follows these frameworks for limits to radiation.
The recommendations and reports that each organization sends out share
the same basic data and the positions they take are almost entirely the
same. They also critically examine each work of scientific literature (out
of a vast total number that are published), and many times they publish
criticisms, even of scholarly papers published in academic journals. Their
uncompromising stance on basing recommendations on scientific evidence
has improved the reliability of the agreements among these organizations,
and this is why countries follow their recommendations.
European Committee on Radiation Risk (ECRR)
The organization called ECRR, or the European Committee on Radiation Risk,
7776
is separate from ICRP. It is a non-profit organization that does not have any
relation to the UN or to national governments. Many of the participants are
scientists and experts who advocate anti-nuclear positions, and they conduct
activities that seem to counter those of ICRP.
For example, ECRR reports contain some extreme statements, such as that
the effects of internal exposure to radiation are 600 times that of external
exposure, and if people do not evacuate but keep on living where they are,
more than 416,000 people living within a 200 km radius will develop cancer
within the next 50 years due to the Fukushima nuclear accident. These claims
are widely contested for their lack of scientific evidence and are mostly
ignored by international organizations.
I will add that the central figure in their activities, Chris Busby, makes fervent
claims about the threat of internal exposure to radiation, while on the other
hand he sells expensive “supplements” that he claims are effective against
exposure to radiation.
(2) International rules to protect people from exposure to radiation
The Normal Standard: 1 mSv Annual Exposure
ICRP recommends that exposure to radiation that is caused artificially
(excluding medicine) should normally not exceed an annual level of 1 mSv.
This figure is raised in emergencies, such as immediately after a nuclear
accident, to permit an annual radiation exposure range of 20 mSv to 100
mSv for residents (ICRP’s 2007 recommendation). Once the accident is in
the recovery phase, the limit returns to a stricter level, a recommended
annual radiation exposure level ranging from 1 mSv to 20 mSv (ICRP’s 2008
recommendation).
In other words, they are set in stages as follows:
In normal times: 1 mSv
↓ ↓
In emergencies/in the immediate post-accident phase: 20-100 mSv
↓ ↓
In the rehabilitation (recovery) phase: 1-20 mSv
The idea that the standard for permissible doses of radiation can be eased
temporarily is based, as I wrote in the previous chapter, on reflections on how,
at Chernobyl, a strict evacuation standard of 5 mSv per year was adopted and
ended up shortening evacuated residents’ average lives (and was found to
have caused the most serious health hazard).
Based on ICRP’s thinking, the Japanese government announced a policy to
set the maximum annual limit of exposure to radiation at 20 mSv when they
determined that the situation was headed toward recovery. However, this
sparked a controversy.
There was opposition to this policy because the public did not understand
the rationale for applying standards flexibly depending on changes in the
situation (normal → accident → rehabilitation). They reasoned, “If the usual
limit is 1 mSv, how do they expect us to tolerate 20 mSv?” They thought that
the government was changing the standards as a makeshift to make it look
like standards were being met.
This impression was made worse by experts who had joined the government
as cabinet advisors and who gave a press conference in April at which,
claiming that it offended their conscience as scientists to allow annual
radiation exposures of 20 mSv, they quit their posts in tears. This undeniably
gave many people the impression that 20 mSv is dangerous -- although it is
true that some misunderstandings are attributable to media reports on this
event as well.
The government followed the ICRP recommendations and chose the
maximum 20 mSv based on the 1 mSv to 20 mSv standard range of allowable
levels for the recovery period. The most pertinent point here is that an
international standard states that up to 20 mSv is acceptable, and this was a
major premise for the government’s decision.
It is important to emphasize that this was within the range of established
standards, not merely a convenient makeshift. The lack of adequate
explanation on the part of the government, which made people distrustful, is
regrettable.
Overreactions Have Harmful Side Effects
Some people feel that the level should be brought back to the normal level of
1 mSv once the emergency is over. However, establishing planned evacuation
7978
zones where annual radiation doses would exceed 20 mSv had already
turned thousands of people into refugees. To reduce the tolerance further
to 1 mSv would undoubtedly condemn even more people to uncomfortable
lives at evacuation centers and make progress towards reconstruction even
harder.
I repeat: the less radiation one is exposed to, the better. However, realistically
speaking, choosing an attainable limit within the “safety zone” and moving
towards a future goal of reducing radiation to as close to zero as possible is
the approach most likely to protect people’s health and livelihoods. I have
stated already that, in the current state of medical science, cancer risk is
known to rise only when exposure goes over 100 mSv. No effect of less than
100 mSv of radiation has been proved. So if we are thinking in terms of the
scientific evidence we have, the upper limit to radiation exposure -- whether
it is in normal times, in emergencies, or during the subsequent recovery
period -- should always be 100 mSv.
However, physicians, other scientists, and experts on radiation protection
have different ways of thinking. The massive amounts of scientific data
from Hiroshima and Nagasaki point to 100 mSv as a critical point or “cliff ’s
edge” between what is safe and what is dangerous, but running through the
thinking of radiation protection experts is the notion that the public should
not be made to suffer any consequences of unnecessary exposure.
In other words, the standards adopted to ensure the public’s protection from
radiation are much more cautious and, shall we say, prefer to err on the side
of safety, compared to the scientific critical point of what is known to be safe
and what is not. Another way of saying this is that, even if actual exposure
to radiation exceeds the standard for protection by a little bit, it is at a level
that will not affect one’s health. Rather than pursue a debate over which one
is correct, the scientific evidence-based standard or the radiation-protection
policy standard, we should try to understand the differences.
ICRP’s Message Regarding Fukushima
Several documents have been published that are very useful in thinking
about how to tackle the problems of radiation in Fukushima. ICRP Publication
111, Application of the Commission’s Recommendations to the Protection
of People Living in Long-term Contaminated Areas after a Nuclear Accident
or a Radiation Emergency, is a recommendation that was specially re-issued
by ICRP as a message to the people of Fukushima. It was originally issued
by ICRP in 2008, but was re-issued on April 4, 2011, after the emergency in
Fukushima. I will tell you more about this later, because it contains helpful
advice for people living with the effects of radiation.
The nuclear power plant site is presently moving towards “putting out
the fire”: the reactor is being cooled stably, and the amount of radioactive
substances being released has lessened. However, the people who lived
around that area continue to be forced to live far from the place they love.
They have to live in constant awareness of the steps they need to take to
protect themselves from radiation. This is really tough to do. Without the
support of the national and local governments and relevant authorities, these
people’s future is shrouded in darkness.
It is probable that most of the people forced to leave their land hope to
return and to live there again if they can. However, in order to do this they
must overcome hurdles, and this will require major efforts on their part. ICRP’s
report serves as a guide in this process. I think by using this guide well, people
can avoid not only direct adverse effects due to radiation, but also other
inconveniences such as limitations on what they eat caused by excessive
concern about contamination in the food and lack of exercise caused by fear
of going outside.
Note also that there is a gap between how people living near the nuclear
power plants and how people living in the Tokyo metropolitan area think
about the problem of radiation. Because the situation undermines our
confidence in our country’s future, it is important for as many citizens as
possible to share an awareness of the problems of radiation. I will go through
the points the report makes in a way which is easy to understand.
Point 1: “Emergency exposure situations” are followed by “existing exposure situations”.
The “emergency exposure situations” they are talking about here are the high
levels of exposure to radiation immediately after a nuclear accident, in which
governments order emergency evacuations and standby operations. It is the
same situation that the area around the Fukushima nuclear power plant was
placed in from March to April, 2011.
8180
The term “existing exposure situations” refers to situations, after emergencies,
heading towards rehabilitation or recovery. The nuclear power plant is in a
situation where it cannot yet be controlled, but the release of radioactive
substances into the atmosphere has been reduced, changing this emergency
situation to a situation of exposure to existing radiation. That is point number
one. This is the situation that people in Fukushima and all Japanese are facing
right now, an exposure to existing radiation.
Point 2: Management of exposure proceeds by individual dose.
Since the amount of exposure to radiation in a nuclear accident differs greatly
based on the individual’s behavior (lifestyle, diet, evacuation, etc.), it is not
appropriate to put in place measures that hypothesize an average level of
exposure. It is necessary to put in place detailed measures that study the
exposure of individuals or evaluate groups based on their level of exposure.
This presumably includes distribution of personal dosimeters.
Point 3: It is important to optimize and to justify protection measures.
Optimization of protection measures means avoiding the adverse effects
of exposure (through evacuation, etc.), but the balance of socio-economic
elements (the losses in income, pride, and purpose in life that come with
evacuation) must also be considered, and that means that the optimal
method of protection should be chosen taking these elements into
consideration. Because all exposure protection measures impose some
greater or lesser degree of inconvenience on surrounding populations,
depending on how extensive they are, they must be justified by showing
that these measures are necessary and take into consideration the balance
between the risks of exposure and the inconveniences imposed on residents.
For example, to evacuate people from areas where the exposure level is one
that has absolutely no effect on the human body would harm, not protect,
the population.
There is a need to define clearly and make public the assumed conditions
and data that serve as the evidence for deciding protection measures. The
premises are that (1) all important information is being provided to the
parties in question and that (2) third parties can confirm the validity of the
entire decision-making process leading to the measure’s adoption.
Point 4: Define the reference level.
The reference level is the dose above which evacuation and other measures
should be taken. This number is only a guideline, however. ICRP states
that the reference level in existing exposure situations (during recovery/
rehabilitation) should be set to between 1 to 20 mSv annually (this is why
the Japanese government adopted the limit of 20 mSv). After that, they set
the long-term limit at 1 mSv. They also state that even if the exposure is less
than the reference value, protective measures should be taken if there is any
chance of reducing exposure.
Point 5: Participation of residents (protection through self-help) is needed.
It goes without saying that residents are worried about the effects of
radiation. In addition, they probably expect the prefectural and national
governments to respond and may mistrust those responses at times.
However, there is a need for residents to act on their own behalf as well.
It is important for residents to adapt their behavior to the post-accident
rehabilitation environment to decrease their exposure; they can do this by
taking note of locations where radiation levels are high and not entering
those areas, by avoiding foods that are easily contaminated by radioactive
substances such as mushrooms and wild greens, and by monitoring their
own exposure and helping to support children and the elderly. In addition,
residents should actively participate in regional council meetings that debate
rehabilitation and how to decrease exposures.
Point 6: The authorities (prefectural and national) have the responsibility for this.
The authorities should not only protect the people who have been most
exposed to radiation, but also draft radiation protection policies and
measures to decrease each individual’s exposure as much as possible, and
show proof of this.
In addition, it is their responsibility to determine what areas are inhabitable
and guarantee the general convenience of habitation in those areas.
Besides these responsibilities, the authorities should also measure and
monitor individual exposures, decontaminate buildings, improve the
8382
condition of soil and vegetation, review how livestock should be raised,
monitor the environment (air, soil, etc.) and agricultural products, provide
safe food, process waste, inform the public, provide guidance to residents,
and educate children.
The Dilemmas Confronting Us
These six points that were cited in the ICRP report clearly show what roles
the national government, local governments, and residents themselves play
in reducing damage caused by exposure to radiation and in moving towards
rehabilitation. However, as I read this report, I could not help but think of the
dilemmas we are facing.
For instance, it is extremely hard to determine what is the best protection
measure (cited in Point 3). Let us take agricultural products.
If the regulations for radioactive substances on agricultural products are
excessively strict, restrictions imposed on the shipment of vegetables will
become so stringent that local producers will not longer be able to do
business. Attempts to protect consumers will adversely affect producers.
In this case, it is very important that local residents and other citizens reach
a consensus, and at times it is important also to leave things up to the
discretion of individual citizens, on the basis of national regulatory standards.
In addition, there are problems with setting the “reference level” described
in Point 4. This is a matter of the balance between the risk of exposure to
radiation and the wishes of local residents (i.e. whether or not they want to
remain where they are and keep living in their homes). The government has
set the limit for annual public exposure to radiation at 20 mSv in the post-
accident phase while things are returning to normal. If the exposure exceeds
this level, the area will be evacuated.
So in other words, people can stay and live as usual in areas that are exposed
to less than 20 mSv annually. There are many people who feel a sense of
purpose and even advantages in staying where they are to till their fields
and raise their cattle even if they know they incur a small risk by exposing
themselves to radiation. Of course, some, unlike the others, will want to
start a new life in a new home. For example, sensitivity to radiation varies
depending on age. If exposed to the same amount of radiation, middle-
aged people and the elderly will not be affected as much as are children and
younger people. The decision whether or not to leave one’s home and land
depends, therefore, to a certain extent on one’s age.
In this way, individuals each make their own decisions -- but do not doctors
and other scientists and experts have the most important responsibility to
provide accurate and detailed information about radiation so that people can
make appropriate decisions? The government should not take measures to
forcefully evict residents, but respect their wishes; instead, the government
should ensure first that they have the residents’ understanding, then draft
flexible rules.
ICRP Publication 111 points to a basic way of thinking for moving toward
overcoming the problems of exposure to radiation in the wake of a nuclear
accident, but it does not give detailed instructions. That was left to the
discretion of the people of Japan. That is our decision.
8584
Fukushima’s Current Situation (2011)
The Problems Are Piling Up
As I write this book, not yet ten months have passed since the accident at
Fukushima Daiichi Nuclear Power Plant. The work of repairing damage to
the nuclear power plant has proceeded in fits and starts, a series of trial and
error attempts, but TEPCO has announced that they will bring the reactor
to a “cold shutdown” by the end of 2011. The highest levels of radiation at
the perimeter of the nuclear power plant site have reached an annual level
of 0.2 mSv (as of October 2011). This means they have dropped to roughly
1/8,000,000 of the level of exposure after the accident.
However, the problems are still accumulating. There are still challenges that
remain and will require time, money, and wisdom to overcome, such as the
decontamination of 23 times the surface area of Tokyo Dome (Japan’s “Yankee
Stadium”, 112,456 square meters/27.8 acres), processing of nuclear power
plant-related waste, and establishing lifetime medical care for all of the 2
million people in Fukushima prefecture. Now is the time when Japan’s true
national potential is being tested.
In this chapter, I will write about the current situation in Fukushima ten
months after the disaster, and my experiences in periodically visiting Iitate-
mura after the earthquake. I hope it will provide some guide to the making of
decisions when faced with the future challenges of dealing with exposure to
radiation.
Future Risks From Radioactive Substances
The nuclear power plant itself has not yet returned to normal or been
repaired, but it now releases hardly any radioactive substances into the
atmosphere. Currently, there are hardly any radioactive substances in the
atmosphere or water supply. There is no need to wear a mask to prevent
yourself from inhaling these substances, nor is there a reason to wear long-
sleeve clothing to avoid exposing your skin. It goes without saying that I, too,
am drinking tap water as usual.
However, the cesium that fell on the ground in March is still a cause of high
doses of radiation. In Fukushima-shi, 60 km away from the nuclear power
plant, the radiation dose detected in the air remains at 1 micro-sievert per
hour. If one stays in this environment for a whole year, the annual exposure
would amount to roughly 9 mSv. However, this is a value that does not
require concern.
What’s more, when people in Fukushima-shi actually go out and measure
external exposure with their personal dosimeters, their readings are
significantly lower than 9 mSv.
Within a few days of the accident until the end of March, the cesium released
from the nuclear power plant was carried by the wind and dissolved into the
rain, which in turn fell down to the ground. The gamma rays emitted by this
cesium are a cause of external exposure. As I stated in Chapter 1, the half-life
of cesium-137 is long, 30 years, so it will still be around for quite a while. In
other words, unless the area is decontamined, gamma rays will continue to
be emitted.
On the other hand, the half-life of iodine is eight days. We can assume that all
of this radioactive iodine has disappeared.
The Ill-Timed Order to Evacuate to Iitate-Mura
Iitate-mura, roughly 40 km northwest of the nuclear power plant, was not
designated as an evacuation zone immediately after the accident. It was
actually a destination for residents around the nuclear power plant to
evacuate to. However, because the wind had blown northwest from the
nuclear power plant, high doses of radiation were recorded there and the
town was re-designated a “planned evacuation zone”. This caused great
confusion among the town’s residents, who thought they were safe because
they were located at such a great distance from Fukushima Daiichi.
I actually went into Fukushima on the bullet train and measured the level
of open-air exposure in Fukushima-shi, Iitate-mura, and Minami-Soma-shi;
my readings showed that the radiation was highest in Iitate-mura, then in
Fukushima City (seat of the prefectural government), and lowest in Minami-
Soma-shi. The reason why Minami-Soma-shi, the closest to the nuclear
power plant, had the lowest reading is that winds carrying the radioactive
substances did not blow in that direction.
Chapter 6Fukushima Now and in the Future
8786
The result is that people who fled localities close to Fukushima Daiichi might
be exposed to higher levels of radioactivity at their presumably “safer”
destinations than they would have if they had not evacuated. It is extremely
regrettable that correct evacuation instructions were not given, because the
authorities did not know basic facts regarding how radioactive substances
are spread. However, I should add and confirm that the level of exposure to
radiation at that time was very low, not enough to increase the risk of cancer.
The Truth About External Exposures
Some people have calculated that somebody will be exposed to 9 mSv
annually if they are in a park that has an exposure level of 1 microsievert/
hour for a year, but this assumption is nonsense. For one thing, the amount
of external exposure changes a great deal if you just move a few meters away
from a given spot.
Cesium carried by the wind gets dissolved in the rain that in turn gets
absorbed by the soil it falls upon. Therefore, radiation in the open air changes
greatly depending on the direction the wind is blowing in, precipitation
and other weather conditions, the terrain, and the nature of the surface
it falls upon. The radioactive substances released from Fukushima Daiichi
were carried by the wind between March 15 and 21, and even went as far
as the Tokyo metropolitan area. The amount of cesium carried on the 15th
was greater, but fortunately no rain fell on that day and it just passed right
through. However, with the rainfall on the 22nd, cesium was deposited on
surface soil.
When dissolved in water, cesium forms positive ions. Because soil is
negatively charged, positively charged cesium is absorbed into the soil. The
place where the winds brought cesium on both March 15th and March 22nd
was around Kashiwa-shi. This area thus became a “hot spot”.
Hot spots are found particularly in places where there was heavy rainfall
and through which winds carrying cesium passed, and in parks and other
places where there is a lot of exposed soil. Exposures inside buildings, on the
other hand, are much less than exposures outdoors. Even in wooden houses,
exposure is about 40% of the level outside, and less than 20% in apartment
buildings and other reinforced concrete buildings. So in the final analysis, the
level of an individual’s exposure to external radiation can only be known if
they have been carrying around a dosimeter.
External Exposures in Fukushima
So-called “glass badges” are handy ways to measure individuals’ doses from
external exposure. These dosimeters are used in hospitals; when radiation
hits a special kind of glass, a chemical reaction occurs, and the properties of
this glass are used to “remember” the amount accumulated. The amount
of exposure is measured by having people carry a small case with this
glass inside at all times. The measurements from these glass badges are
yielding useful findings. It has been reported that the amount of radiation
accumulated between July and September by the roughly 2,500 people in
Kawamata-cho was at most roughly 1 mSv over three months. Similarly, it was
found from the measurements of roughly 8,400 people in Date-shi during the
month of August that annual exposure levels did not exceed roughly 5 mSv
at most.
Such an annual exposure to 5 mSv is indeed greater than the exposure limit
of 1 mSv for normal times, but it is still below the level at which cancer rates
would increase, so this should not worry anyone.
Internal Exposure in Fukushima
At Chernobyl, restrictions on the consumption of milk, etc. were not imposed
until too late, and nearly 1% of children under four years old had their thyroid
glands exposed to over 10 Sv (10,000 mSv) of radiation -- an immense dose.
In Fukushima, restrictions were put on milk and food items and people were
evacuated immediately after the accident occurred. As a result of actually
measuring the amount of exposure in the thyroid glands of over 1000
children in Fukushima, it was found that the maximum exposure was 35 mSv.
The figure in Chernobyl was three digits (roughly a thousand times) greater,
and no increases in cancer rates come from thyroid exposures less than 50
mSv.
We can therefore predict that there will be no increase in thyroid cancer in
children in Fukushima.
In addition, studies on Fukushima residents are making it increasingly
clear that the observed levels of internal radiation due to cesium are
not preoccupying. A study of amounts of internal exposure measured
8988
continuously until the end of September by 4,463 people from Fukushima
prefecture found that two people showed readings of 3 mSv -- and this was
the highest value detected. In addition to these two, eight people were
exposed to 2 mSv, six people were exposed to 1 mSv, and the remaining 4,447
people were exposed to less than 1 mSv of radiation. There are probably
many people who feel insecure because even a minute amount was
detected. This is not, however, a level at which cancer rates increase. I repeat:
there is no scientific proof that cancer rates increase at exposure levels of less
than 100 mSv.
On the other hand, from a radiation protection point of view and to be safe,
ICRP (International Commission on Radiological Protection) advocates the
linear no-threshold model, which assumes that cancer will increase at even
very small exposures, less than 100 mSv of radiation. Their policy is that the
less exposure to radiation, the better. And yet even ICRP states clearly in a
report (ICRP Pub 96, Table 3.1) that cancer does not increase at 10 mSv.
There are, it seems, two sets of standards, one for 100 mSv and the other for
10 mSv, so there may be people who are confused about this. While no data
point to an increase in cancer at exposures under 100 mSv of radiation, 10
mSv is regarded as a level at which one can say definitively that no increase in
cancer occurs.
According to studies conducted this September, hardly anyone’s exposure
has reached 10 mSv due to the accident at Fukushima. I repeat again: cancer
will not increase in Fukushima.
(2) My Visits to Iitate-mura
My Visits to Iitate-mura and What I Saw
In my radiation therapy work at the University of Tokyo Hospital, I team up
with doctors, nuclear industry engineers, theoretical physicists, and medical
physicists. Beginning in late April 2011, together with this team, I periodically
visited Fukushima.
We went into Iitate-mura, spoke with residents, and also interviewed the
mayor, Mr. Norio Kanno. I came across so many things there that I had not
noticed or seen when I was in Tokyo that I was ashamed of my lack of insight,
but in addition to my lesson in humility, I got a feel for the problems that
people in these areas were facing. For example, meeting and talking to
people there brought home to me how different residents felt very differently
about the very same term, “evacuation”. Even among farmers, the way people
feel about evacuation depends a lot on whether or not they raise livestock.
Livestock farmers give a compelling argument. They say, “our livestock are
family. Even if we evacuate, the livestock will need to be cared for every day,”
and “People have trouble adjusting to unfamiliar land; cows have trouble,
too: the amount of milk we get from them falls to half.” Pregnant women and
parents with infant children are haunted by terrible anxieties. Such being the
case, we presented the results of our team’s radiation dose measurements in
the village in the following way.
We told them: “Judging from our cumulative radiation estimates, the levels
we found are not enough to justify extreme fears of increased cancer risk
in adults. The risk is lower than the risk of eating too much salty food or too
little vegetables. One alternative for you is to decide to evacuate only the
pregnant women and infants. But all things considered, the stresses of living
in an evacuation center would be cause for more concern than the radiation.”
We then had a talk with the mayor, Mr. Kanno, and we reached an agreement
about what we would do. Our team would hold a lecture at which we would
explain to the village the effects of radiation exposure on health. We did this
because not knowing things and not having enough information are the
biggest causes for anxiety. Family situation, age, health status, etc. naturally
differ from one person to the next. Given that it is so difficult to decide,
we offered to provide materials so that residents could consider their own
situation and decide themselves what is best for them. I considered that this
was the best way to relieve their anxiety.
Intensive-Care Nursing Homes: Evacuate or Stay Put?
There is an intensive-care nursing home in Iitate-mura. I talked to Mayor
Kanno regarding the evacuation of people in this facility.
The mayor asked me, “Wouldn’t it be better for the residents to stay in the
facility, rather than to be separated from each other, placed in gymnasiums
and evacuation sites like that all over the place?”
The average age of the nursing home’s residents is roughly 80; some are
over 100 years old. In contrast to the way fetuses and children are sensitive
to radiation, the risk that the elderly will develop cancer does not increase,
9190
even when exposed to the same amounts of radiation. In most cases, it takes
10 to 20 years for cancer to develop from exposure to radiation. In addition,
drastically changing their living environments can subject elderly people to
major stresses.
As I wrote in the chapter about Chernobyl, a large-scale migration program
was put in place in Chernobyl, implementing an extremely strict set of criteria
for the evacuation of all residents, and this evacuation significantly shortened
people’s lives. Taking these things in consideration from a physician’s
standpoint, I consider that it’s inappropriate to forcefully evacuate the elderly.
Residents Speak for Themselves
Whether or not to evacuate is a very difficult question. All people have their
own circumstances and ways of thinking, and family makeup and age groups
differ as well. To ignore this diversity and apply one uniform set of guidelines
to all and sundry is not always the best bet. That is how I feel and my feelings
on the subject only grew stronger as I took part in the Q&A session after
a village health affairs counseling meeting and listened to the evacuees’
complaints.
I will cite some of them in the following pages:
“My role in this world is to grow vegetables, so it hurts not to be able to farm. I was supporting myself and self-sustained before.”
“Assuming I go back, what am I supposed to do in a place where there are no young people?”
“Iitate is mostly mountains. You can’t decontaminate that.”
“Will my grandson and his wife come? What about their children?”
“My children are saying they can’t get married, and even if they do get married, they can’t have children!”
“Why didn’t they at least evacuate the children sooner?”
“For information, I trust word-of-mouth first and foremost, and then comes the Internet.”
“I am skeptical about all the information I hear.”
“If I believed everything I’m told I’d go crazy!”
“I cannot sleep because of the stress. I wake up in the middle of the night.”
“These children used to run around in the mountains. I feel so sorry for
them now that they can’t play outside anymore.”
“I was drinking local well water after March 11, even though I’m
pregnant...”
“Won’t I bring radioactive substances back, stuck to my clothes and bags,
if I go in to the village and back?”
“Young people say they don’t want to go back. Even if we go back ten
years from now, we too will all be old folks.”
“Wouldn’t it be better to spend the hundreds of millions on moving
somewhere else, rather than spend it on decontamination?”
These are just some of the concerns they mentioned, but they vividly
portray the grim situation these residents are placed in and the uncertainty
that lies ahead of them.
Some said about evacuation, “Even if we could come back someday, we want
to live somewhere else for now”, or “We just want to move somewhere else
with our whole community, all together”. Others, especially the elderly, want
with all their heart simply to return to the place where they’ve been living
and which they know so well.
Flexibility is necessary in adapting to the circumstances and thoughts of each
person, not just evacuating all villagers regardless of their wishes. I realized
this, not when I was in Tokyo, located so far away, but when I entered
Fukushima and heard firsthand the voices of residents and began to gain an
understanding of the situation.
Verification of Official Published Data
There was another major reason why we visited Fukushima: to measure
radiation levels. Our objective was to study why, within such small areas
as schoolyards, there were different readings depending on the location.
Moreover, many people had let our team know that they didn’t trust the
measured radiation levels announced by the national and local governments,
9392
and so we were there to verify the validity of these official data.
To jump quickly to the conclusion, we found no reason to doubt the national
government’s officially released information. We chose three locations
(No. 32, No. 33, and No. 36) from the monitoring points established by the
Ministry of Education, Culture, Sports, Science and Technology and made
independent measurements of radiation using instruments of the same make
and model as the ministry’s. The values announced by the ministry and the
results of our measurements were as follows:
No. 32; Ministry: 19.5 mSv, Nakagawa Team: 18.3 mSv
No. 33; Ministry: 13.8 mSv, Nakagawa Team: 13.6 mSv
No. 36; Ministry: 2.6 mSv, Nakagawa Team: 2.5 mSv
In all three locations, we found barely any difference between our
measurements and the government’s published figures. The people who
collect these data are serious, hard-working researchers, and these figures are
made widely available to everyone, to people and organizations all over the
world, so under the circumstances, a cover-up is inconceivable.
Keys to Decontamination
Decontamination work is now going on in Fukushima and other parts of the
Tohoku region and in Northern Kanto. What is needed, though, is a more
effective decontamination process that takes the radiological characteristics
of the contamination into account. As I mentioned before, of the various
radioactive substances released in the accident, a particularly difficult
problem is posed by cesium, which has a long half-life and was dispersed in
large amounts.
According to a study conducted in Eastern Europe and Scandinavia after
the Chernobyl accident, the speed at which cesium sinks into the ground
is usually 1 cm a year. Seven years after the accident, most of the cesium
remained within 10 cm of the surface. A lot of rain falls in Japan; cesium from
atmospheric nuclear testing (during the 1950s and 1960s) has been seeping
into the soil since then, but none is found deeper than 30 cm from the
surface. Consequently, intensive decontamination by stripping off the surface soil
is still possible and would effectively remove the risk of radiation exposure
due to cesium. Children playing in schoolyards exercise vigorously and
get covered in dust and mud. The possibility of their inhaling earth dust is
higher in schoolyards than in other places. Since it is especially important to
care for our children in school, decontamination in schoolyards and similar
areas should be given the highest priority from the standpoint of radiation
protection, that is, protecting the public from radiation.
The soil requiring decontamination from the nuclear accident is an estimated
23 times the volume of Tokyo Dome (the world’s largest roofed baseball
stadium, a 55,000-seat structure in Tokyo measuring 1.24 million cubic
meters), an overwhelming amount. It is impossible to process this all at once.
We must establish priorities for the different tasks to be done and proceed as
thoroughly and reliably as possible.
High Exposure Risks for Accident Site Workers
Undoubtedly the radiation to which workers who have been working to
handle the accident day and night since it occurred will have effects on
their health. Because cancer risks increase with annual exposures over 100
mSv, these workers, who are allowed exposures of up to 250 mSv, must be
especially careful in the future.
People who work on the front lines are assumed to be aware of the risks,
and yet they must be urged to undergo regular checkups and screening and
receive other medical care relevant to radiation exposure, and to continue
vigilantly to protect their health for the rest of their lives. Early detection
increases the chances of curing cancer.
Cancer Rates in Fukushima Will Not Increase.
In the Chernobyl accident, 28 of the firefighters and workers who went into
the site of the accident on a suicide mission died within three months due to
acute radiation damage caused by exposure to massive amounts of radiation.
At the Fukushima nuclear power plant, workers were at least able to avoid a
situation in which they absorbed a large amount of radiation instantaneously.
Although two workers were hospitalized due to acute exposure to radiation,
no one is presently hospitalized, and no one has died. This is a big difference
between Chernobyl and Fukushima.
The increase in thyroid cancer in children that occurred in the general
population in Chernobyl will not happen in Fukushima, either. It has been
9594
confirmed that the internal exposure of the thyroid gland to iodine, and
the amounts of external and internal exposure to cesium, are much lower
than at Chernobyl. This is because, as I explained in Chapter 4, restrictions
were placed on the intake of contaminated foods and milk in Fukushima
promptly after the accident. This was a very important lesson learned from
the Chernobyl accident, and it was put to good use.
Balancing Risks While Making Urgent Decisions
On April 22, the area within a 20 km radius of the nuclear power plant in
Fukushima was defined as a security zone based on the Basic Act on Disaster
Control Measures. It was the first time that people have been barred (in
principle) from entry into such a large inhabited area.
Outside of the 20 km radius, areas for which annual cumulative radiation
doses were predicted to exceed 20 mSv were designated as planned
evacuation zones.
Additionally, some areas in a 20 km to 30 km radius of the security zone were
designated as emergency evacuation preparation zones; orders were given
to prepare in these areas to take refuge indoors and to evacuate in the event
of an emergency.
The number of people living as refugees away from their homes due to the
accident is said to be 70,000 people. It is natural that many of those living
now as refugees want to return to the land they love as soon as possible. Of
course, if they return to their homes while radiation levels are high, the risk
of exposure will increase. On the other hand, the stresses and psychological
damage that come with living hemmed in and miserable in refugee centers
increase day by day. This is also a risk. We need to think about balancing
these risks to choose the best path for each individual.
We must move quickly to provide realistic answers to complexly interwoven
challenges involving health, environment, economics, psychology, and ethics
(in other words, the challenges of life itself amidst a multitude of risks). This,
seemingly a philosophical proposition, poses real challenges in people’s
daily lives. Living from one day to the next requires that deep and difficult
decisions be made.
The elements needed to help us decide are accurate data and a correct
understanding of the risks of exposure to radiation. First and foremost,
what the government and authorities must do is to fully inform community
residents and citizens, produce a long-term radiation protection strategy, and
make everything as easy as possible for those concerned to understand.
9796
Ten months have passed since the nuclear accident occurred in Fukushima.
Initially, many people evacuated after the accident to Iitate-mura to avoid
exposure to radiation. They didn’t know that radioactive substances from
the nuclear accident in Fukushima would be carried far away by winds. For
example, there were strong winds blowing north-westwards from the nuclear
power plant, and as raindrops fell, those radioactive substances fell to the
ground. Compared to other locations equally distant from the nuclear power
plant, the amounts detected in the area north-west of the plant, where Iitate-
mura is located, ended up being clearly higher than elsewhere.
Initially, this was overlooked and an evacuation zone was established after
the accident based simply on the radial distance from the nuclear power
plant. Even in locations equally distant from the nuclear power plant, there
are locations with both heavy and light contamination depending on the
wind direction; detailed evacuation plans should have considered these
points.
The nuclear power plant is currently moving into the recovery phase.
However, basic knowledge is the ingredients you need to make decisions and
act in a calm manner, no matter what happens in the future. What is more,
radioactive substances, even if the amounts are extremely small, are being
detected here and there nearly everywhere. There are some facts that we
need to know in order to avoid further exposures.
In this chapter, I will write about what we can do to prevent exposure to
radiation. Take note that there may not even be any need to take these things
into consideration in the future, given the current radiation doses. I still hope
that you will stock and keep this information in the back of your mind, to be
used in times of emergency.
1. Escape in a direction perpendicular to the direction the winds are blowing.
As I explained in Chapter 1, radioactive substances spread like pollen. If the
winds are blowing northwards from the nuclear power plant, radioactive
substances will be carried by this wind and travel north. Evacuation is quite
simple. You should pay close attention to the weather forecast, and escape in
a perpendicular direction (at right angles) to the way the winds are blowing,
so in this case that would be either west or east. This is the speediest way
for you to escape from the path the wind takes when carrying radioactive
substances.
2. Do not leave laundry outside to dry.
In areas around volcanoes such as Sakurajima and Asamayama, volcanic
ashes spewed out in eruptions sometimes pile up on roads, fields, rooftops
of houses, and windshields of cars. Radioactive substances behave in a very
similar way to volcanic ashes. If laundry and bedding is left outside to dry,
radioactive substances will stick to them.
Whenever and wherever the amount of radioactivity detected is high, I
recommend that you do not leave laundry outside to dry; presently, however,
there are barely any radioactive substances in the atmosphere, including in
Fukushima Prefecture, so it is safe to leave laundry outside. Sunlight has the
ability to disinfect (kill germs), so usually, in terms of hygiene, drying laundry
outside is better than drying it inside. For those of you who still worry, you
can put covers on your bedding when you air it outside. The radioactive
substances sticking to the covers can be brushed off easily before bringing
them inside.
3. Refrain from going outdoors.
Compared to being outdoors, the risk of being exposed to radioactive
substances lessens when you stay indoors. For instance, exposure to radiation
inside a concrete building is less than 20% of exposure outdoors. Concrete
buildings provide shielding from radiation, and also prevent radioactive
substances from coming inside. Exposure inside wooden houses is roughly
40% of the outdoor level.
There are some people who claim that retreating indoors does not have
much of an effect, but they are wrong. The effect of retreating indoors comes
from the fact that the building shields people from radioactive substances
in the atmosphere and radioactive substances that adhere to the ground
and outsides of buildings. You should avoid going outside when you don’t
need to, but there is no need to worry if you wear a gauze mask and clothing
that does not expose your skin. Commercially available masks are effective
in preventing dust in the atmosphere with radioactive substances stuck to
Chapter 7Responses to Radiation Exposure in Times of Emergency
9998
it from getting into your body. To be even more thorough and for greater
protective effect, you can hold a wet towel or handkerchief to your nose and
mouth.
When coming back from outside, make it a point always to brush off your
clothing to rid yourself of the radioactive substances that have stuck to
them, and to gargle. By doing this regularly, not only will you be removing
radioactive substances, but this will also be effective for hygiene. However,
there is no need to change clothes every time you come back home from
outside.
Radioactive substances reach the ground via rain, so you should try to stay
out of the rain as much as you can.
4. Be suspicious of wild vegetables and edible mushrooms harvested outdoors.
To avoid taking in radioactive substances through food intake, you can
remove radioactive substances that may have adhered to your food by
peeling off the outer layer of cabbages and Chinese cabbage, and carefully
peeling the skin from potatoes, carrots, etc. You should thoroughly rinse leafy
vegetables such as spinach and komatsuna.
Commercially distributed food products have passed inspections to get to
storefronts, so there basically is no problem. (However, spot checks of certain
shipped food products have detected radioactive substances that exceed the
national provisional limits.)
The national and prefectural governments will send out information if the
amount of radioactive substances in drinking water and food products are
found to exceed the regulatory limits. If this kind of information is not being
reported, it is safe to think that levels are within the regulatory limits.
It would be wise not to eat foods that individuals gathered in the mountains,
since those foods have not been inspected pre-shipment. In particular,
mushrooms and wild vegetables have a tendency to build up concentrated
levels of cesium, so you need to be careful.
For example, Iitate-mura is a treasure house of wild vegetables. I hear that
many people were looking forward to picking wild vegetables. However, it is
known that cesium is easily concentrated in flowering ferns and mushrooms
and things like that. When I went to visit in April, roughly a month after the
accident, I conducted quick radiation measurements on spinach and wild
vegetables that were provided with the cooperation of residents of Iitate-
mura. The results showed that extremely high doses of radiation were
detected, as follows:
Type: Cs-134 Cs-137
Fatsia sprouts (Iitate-mura) 2874 becquerels/kg 3528 becquerels/kg
Flowering fern (Iitate-mura) 10240 becquerels/kg 13242 becquerels/kg
Fukinoto (Namie-machi, point 32) 9681 becquerels/kg 12061 becquerels/kg
(Note: The becquerel is another unit of radioactivity. Food products are not
allowed to be shipped if the level exceeds 100 becquerels.)
The team I was a part of advised residents not to eat the wild vegetables they
had picked themselves.
5. Small children are more susceptible to the effects of radiation.
There are ditches and rain gutters around us all, and there are some points
in which rain water containing cesium easily accumulates. There are times
when radiation doses are higher and radioactive substances are more highly
concentrated in these places than in other locations. It is important to be
careful that children do not stick their hands inside the pools of water that
accumulate under rain gutters, or drink this water. It is also wise to prevent
them from breathing in clouds of dust in these areas. This is because, even
when exposed to the same amount of radiation, children can develop cancer
more easily than adults. By the way, the effect on the thyroid gland when
radioactive iodine is taken in (what they call the equivalent dose) is 10 times
that of an adult. However, the amount of food intake for children is less than
adults, so they take in smaller amounts of radioactive substances.
If you are worried about the radioactive substances in the atmosphere, you
can try to avoid ventilating rooms in which infants stay, or when ventilating,
use ventilation equipment with very fine filters to prevent radioactive
substances from entering the room. If you are worried that radioactive
substances enter the room and stick to your bedding, couches, or rugs even
while you are quickly opening or shutting your windows, you can vacuum
frequently to remove them.
101100
6. Be especially cautious about what your children put in their mouths.
We cannot with any certainty deny the possibility that exposure to radiation
can come from such sources as cesium contained in food and drinks such as
milk that children take in. In general, there are no problems with commercially
available milk and dairy products, but you should check the information that
is sent out by the national and prefectural governments. Furthermore, as I
wrote in Chapter 4, the safety regulations regarding radiation which might
cause internal exposure will become even stricter in the future.
The Ministry of Health, Labour and Welfare has announced a policy to lower
the provisional limit for radioactive cesium from 5 mSv a year to 1 mSv a year.
This is because the Food Safety Commission of Japan, which reports to the
Cabinet Office, has published a report evaluating the effects of radiation on
health due to internal exposure from food; it reports that effects are seen
when lifetime accumulated exposure exceeds 100 mSv. For example, the
provisional regulatory limit for vegetables is 500 mSv/kg, but if we simply
divide that by 5, then 100 mSv will become the new limit. This is 1/12 of the
regulatory value set in the United States, so for producers it is an extremely
stringent standard. With this revision of the limit, fears of internal exposure
to radiation should be even further reduced, and this should bring peace of
mind to people in Japan.
Furthermore, the current provisional regulatory limits for radioactive cesium
are set in five categories: drinking water, milk/dairy products, vegetables,
grains, and meat/eggs/fish/other. In the future, these five categories will
be reorganized to meet international standards, and there will only be four
categories: a new category, baby foods, which will include powered milk, etc.,
plus the three remaining categories: general foods, drinking water, and milk.
With this change, new regulations will be imposed on foods for children, who
are more susceptible to the effects of radiation, and this should put the minds
of parents of small children at ease.
In addition, sometimes I hear stories of children in so-called hot spots where
high levels of radiation have been detected who accidentally put their muddy
hands in their mouths while they are playing in mud. Small children will put
anything in their mouths, so there is a need to be careful. In general, the
amounts of radioactive substances detected thus far are not high enough to
warrant concern about the effects of internal radiation in children who have
put mud into their mouths like this just once or twice. However, parents do
need to be careful that children do not repeatedly do this. (This is not solely
because of the effects of radioactive substances: it is also because eating mud
in itself may have adverse effects on the child’s health.)
7. To move away or not to move away should not be decided hastily.
I hear people say they are wondering whether or not to move away because
they live in a place with high radiation doses. I think that asking for an
expert ’s advice about how much radiation you would be exposed to by
living there for one year is a good way to get an estimate to base your
decision on. Evacuations are semi-compulsory, but moving is something you
have a choice about. Relocating entails economic burdens and greatly alters
your living environment. It is a very hard decision to make on your own.
Before making this important decision to relocate, it would be wise to
decontaminate the roof, walls, window frames, crevices in which water is
easily collected, and soil of areas surrounding your home. There are cases in
which people carefully vacuum up the dust inside their houses but still have
continually high radiation doses detected, for example, only in the rooms
facing south. This may be the effect of radiation from radioactive substances
in the garden or yard. Removing a few centimeters of surface soil and weeds
in your garden or yard will probably decrease the radiation doses in those
rooms.
Fukushima Prefecture has published a Guide to Measures for the Reduction
of Radiation Doses. I recommend that you use this as a reference when
decontaminating your property because it is a detailed and very user-
friendly manual. It also writes about how you should go about disposing of
the surface soil that you removed. If you are equipped to measure radiation
doses, it would be good to compare your measurements before and after you
decontaminate. Remember that in many regions of the world, annual doses
of natural radiation reach 10 mSv, but residents there suffer no increase in
cancer rates.
ICRP has clearly stated that there is no increase in cancer caused by exposure
to less than 10 mSv of radiation. I think it is safe to live anywhere where
103102
radiation is less than 10 mSv.
8. Unnecessary exposure to iodine and cesium is strictly unnecessary.
There has been no confirmed increase in cancer risks from exposures to less
than 100 mSv of radiation. However, just because it has not been confirmed
is no reason to expose oneself to unnecessary radiation. Based on the ICRP
recommendations, Japan has set the limit for annual radiation exposure to
20 mSv for residents in the post-accident recovery stage. The limit is 1 mSv in
normal times, so we should try to get back to 1 mSv as soon as possible.
Unnecessary exposure to radiation is strictly unnecessary: all reasonable
efforts to decrease exposure to radiation are absolutely necessary.
All kinds of information and statements about radiation have been pouring
from the TV, newspapers, magazines, books, and the Internet since the
nuclear accident at Fukushima. As a physician and a radiation specialist, I am
angry that many imposing statements have been made by people with no
expert knowledge about radiation, fomenting people’s anxieties and fears.
Of course, nothing would be better than never having been exposed to
radiation needlessly. If I could, I would like to get into a time machine and go
back before March 11th.
I have written in this book that there will be no increase in cancer in
Fukushima due to exposure to radiation -- but there may well be adverse
effects on people’s health and happiness due to evacuation and stress. I
personally know a couple that got divorced over the question whether they
should let their child play outside or not. I believe nuclear accidents are a sin
with terrible consequences.
Even so, as a clinician, I cannot stand by idly as people who call themselves
experts feed people’s anxieties by repeatedly claiming that the situation
is dangerous, although they don’t even know the facts about Hiroshima,
Nagasaki, and Chernobyl.
I feel strongly about this because there will be negative health effects if
we fear exposure to radiation too much, at the same time that there will
be negative effects if we fear it too little. In other words, worrying too
much about exposure to radiation does not stop at just being needless
concern: it has negative impacts. This is clear from the fact that people in
Hiroshima enjoy long life expectancies, and from the fact that the average life
expectancy in Chernobyl dropped after the accident.
Cancer will increase if one fears exposure to radiation and lets one’s lifestyle
deteriorate, and life expectancy will be shortened if people who do not need
to evacuate are forced to. In particular, exposure to low levels of radiation
causes hardly any increase in the risk of cancer, but if anxiety is fueled, this
will have negative repercussions on people’s lives, and this worries me as a
clinical oncologist.
In the following pages I would like to describe my personal reaction to some
Chapter 8Addressing Anxieties About Radiation Exposure and Cancer
105104
of the untrue things that some elements of the mass media tell people and
whose truthfulness people have good reason to wonder about. Question: Seven mothers in Fukushima were found to have 2-13 becquerels/
liter of radiation in their breast milk. Is this dangerous?
Answer: A study group from the Ministry of Health, Labour, and Welfare
announced these test findings in June 2011. The radiation is most likely
due to cesium. The level cited, 2-13 becquerels/liter of breast milk, is so low
that it is hard to even tell whether or not that breast milk actually had any
radioactive substances in it.
For example, if a sample of 10 cc of breast milk was taken and tested for
radiation, and this measured level of radiation was multiplied by 100 (to make
it a per-liter figure), its accuracy would be in doubt: the margin of error is too
large in proportion to the sample size. I doubt that a reading at this level has
any meaning at all.
Furthermore, I do not think that there would be any effect, on either the
mother or the child. The amounts of cesium found in the body tissues and the
urine of many children exposed to radiation at Chernobyl is known to have
surpassed 500 becquerels/liter (1 liter of fluid = 1 kg of solid). Even at those
much higher levels, there were no confirmed cases in Chernobyl in which
cesium caused cancer. Furthermore, there is roughly 5,000 becquerels of
radioactive potassium in an adult human body in normal times to start with,
and this does not cause any health problems. Given these considerations,
radiation levels of 10 becquerels fall within the margin of error.
That is not all: relatively large amounts of radioactive potassium are found
normally in fruits and vegetables, so if a person takes in a lot of fruits and
vegetables, there will necessarily be an increase in internal exposure to
radiation. And yet we know for a fact that eating vegetables decreases, not
increases, the risk of developing cancer.
Question: Will congenital anomalies occur more frequently in newborns?
Answer: Some scientists claim that some sort of genetic symptoms will
be caused in children by their parents’ having been exposed to radiation.
However, the studies of Hiroshima and Nagasaki reveal no case where the
effects of exposure to radiation were passed on genetically to children.
UNSCEAR, IAEA, and ICRP (all reliable international organizations) have
reported that such genetic effects have not been seen. There is no cause to
worry in the case of Fukushima, either.
Question: Does it get harder for a person to get pregnant if they are exposed to radiation?
Answer: At even moderate doses (e.g. exposing testes to 100 mSv of
radiation), there are rare cases in which males become temporarily infertile;
they recover spontaneously, however, and this has no e f f e c t s o n
his mate’s future pregnancies or children. Massive exposures to radiation
at levels that can result in death (thousands of mSv) do cause irreversible
infertility. Low levels of exposure to radiation (under 20 mSv), however, do
not make it harder to achieve pregnancy.
Assertion: “We must keep the annual limit to exposure at 1 mSv”
Fact: I hear these kinds of statements made on the Internet and on TV. Of
course, the lower the radiation dose is, the better. However, there is no
evidence that there will be adverse health effects due to low exposures over
1 mSv. There is no scientific evidence for these values.
There is a law in Japan stipulating that the annual level of exposure to
radiation under normal circumstances should be kept under 1 mSv (it does
not take into account natural radiation and the man-made radiation used in
medicine). This is a policy that takes safety into consideration, with a margin
of extra safety. This margin is scientifically based on the level above which the
risk of cancer is known to increase due to exposure to radiation, which is 100
mSv (assuming people live to be 100 years old).
I have explained this in other chapters, but data collected from the studies
conducted in Hiroshima and Nagasaki and data on workers’ exposures at
nuclear power plants and on exposures of medical radiologists and radiation
technicians do not show any verifiable increase in cancer risk due to doses of
radiation lower than 100 mSv.
I am worried about the adverse effects of hastily taking such actions as
evacuation out of one’s fear of exposures to low doses of radiation. As I have
said repeatedly, there is nothing better than not to be exposed to radiation.
107106
But we must realize that forcible evacuation in situations where very little or
no health risk is caused by radiation may cause harmful and unnecessary side
effects. This is a lesson that the Chernobyl nuclear accident has taught us. We
must not forget this lesson.
Assertion: “The ‘deathly ashes’ (nuclear fallout) that were generated by the nuclear accident are equivalent to 800,000 times the amount in the nuclear bomb dropped on Hiroshima. The total heat generated is 29.6 times that of the Hiroshima bomb.”
Fact: These comparisons cite specific numbers, which make them all the
more sensational and excite terrible fears. However, I don’t think that the
comparison of nuclear accidents with nuclear bombings is fair, and it is
meaningless in the bargain.
In an atomic bomb explosion, large amounts of radiation (gamma rays,
neutrons, etc.) are released, killing many people by acute radiation injuries
undergone when they are exposed to the flash. In a nuclear accident, rays
(radiation) are not emitted all at once; the radioactive substances released
from the plant site spread like pollen, and the problem of radiation comes
from that.
There is a big difference in the effects on the human body between being
exposed to a large amount of radiation at once (atomic bombings) and
slowly being exposed to radioactive substances (as happens after accidents
at nuclear power plants), and they should not be treated in the same way.
Let us momentarily overlook our objections to this comparison and calculate
the amounts of radioactive cesium, a component of the “deathly ashes”:
we can say that 168.5 times the amount of cesium that was produced at
Hiroshima was produced as a result of the accident at the Fukushima nuclear
power plant. These numbers by themselves are very surprising. Of course, this
is a very serious situation. I must add, however, that atomic bombs mainly
release gamma rays and neutrons, and the amount of cesium is small: that is
another (perhaps the main) reason why the figure for cesium released after
the Fukushima nuclear power plant accident is 168.5 times what it was at
Hiroshima.
However, let us look also at the similarities between the situations. After the
atomic bomb was dropped, the radioactive substances that did not undergo
nuclear fission rose up into the stratosphere, and after that, some of these
radioactive substances fell to the ground when it rained. This is what people
call “black rain”. The radioactive substances that fell with the “black rain” were
later detected in the north-western regions of Hiroshima, and the eastern
parts of Nagasaki, blown there by the prevailing winds. The dispersion of
radioactive substances was, in other words, almost identical to how they
moved in Fukushima.
However, in the atom bomb explosions, much of the radioactive substances
that were pushed up into the stratosphere did not come back down to the
ground, and were dispersed into the atmosphere. Uranium-235, which was
used in the atomic bombing of Hiroshima, has a half-life of 700 million years.
For its radioactivity to lessen will take an unimaginably long time. If a lot of
this had fallen onto Hiroshima, there would still be effects on the health of
people who currently live there, but this is not the case.
Question: Would it be better to consider moving to Western Japan?
Answer: I think this is utterly pointless. Why? Because the amount of natural
radiation that people are exposed to is higher in Western Japan.
I can understand why someone would move to western Japan to get away
from the trouble of insufficient supplies of groceries and daily necessities and
an inconvenient lifestyle, but I believe that moving west to escape the effects
of radiation is just nonsense. The levels in Tokyo (also in eastern Japan) have
almost returned to normal.
Regions in which there are silver and copper mines and other mineral ores
have higher levels of natural radiation. Gifu Prefecture has the highest levels
of natural radiation in Japan, and the lowest levels are found in Kanagawa.
There is a difference of about 0.4 mSv between the two places. Now, if
you are thinking that there might be fewer cancer patients in Kanagawa
Prefecture, that is actually not the case at all. As I wrote in Chapter 1, the
amounts of natural radiation that we are exposed to on a daily basis are very
small, so they do not have an effect on human health.
Question: I live in a place that is called a “hot spot”, but how many mSv is dangerous?
109108
even stricter. The current limit for annual exposure to radiation in food is 5
mSv, but there is strong pressure to lower this even further to 1 mSv, one-fifth
of the current limit. The Food Safety Commission, upon deliberating on the
effects on the human body of radioactive substances in food, has officially
declared that cumulative lifetime exposure to radiation that people receive
from food should be kept under 100 mSv. If we assume that a life lasts 100
years, a simple calculation gives us a limit of 1 mSv per year.
For example, the current maximum in vegetables is 500 becquerels/kg, but
this will be lowered to 100 becquerels/kg. The regulatory limit for vegetables
in the US is 1200 becquerels, so this is 1/12 of the US regulatory maximum. It
may seem unreasonably strict to impose such demanding restrictions, but I
believe the government has set the limit this low because they expect this to
be achievable.
Of 3,373 people who were studied in a survey of internal exposure to
radiation in Fukushima Prefecture, seven people had exposure levels above 1
mSv -- not even 1% of the total sample. All others were exposed to less than 1
mSv.
Question: Where are we going to put the rubble and soil from Fukushima?
Answer: Where to put the contaminated soil is a tough problem for
Fukushima. This is a problem when decontaminating individual people’s
residences as well. If the radioactive substances accumulated in the gutters
in front of peoples’ houses is simply flushed away, it may end up in front of
the next person’s house. This kind of thing is happening every day. Whether
the decontamination is done individually or on a large scale, we must hurry
to create a system that does not merely shift the burden onto someone else’s
shoulders. Considering this, I think it was a great thing for Tokyo Prefecture to
accept rubble from Fukushima.
Complaint: Malicious rumors are hurting us.
Reply: For harmful rumors to be eliminated, the majority of people need to
share a correct understanding of radiation. It is because people do not know
the facts that some make statements on TV and in the press such as “Don’t
eat vegetables from Fukushima.” I believe that this is the kind of malicious act
that foments harmful rumors.
Answer: There are hot spots in locations toward which winds blew from the
nuclear power plant after the accident. Kashiwa-shi in Chiba Prefecture is
one of these locations. According to data presented by a research group at
Nagasaki University, even if the hourly exposure to airborne radiation is 5
mSv, the individual radiation dose is actually just one-tenth of that. Levels of
airborne radiation do not equal the amount of individual exposure.
Although this is just a reference figure, the level at which radiation becomes
dangerous is when hourly exposures exceed 1 microsievert. That is when we
should pay attention to our exposure to radiation. Japan has currently set the
annual exposure limit at 20 mSv, and is designating for mandatory evacuation
all areas with exposure levels higher than 20 mSv.
As I wrote previously, after the Chernobyl accident, people were forced to
evacuate from areas that had annual exposure levels of as little as 5 mSv --
even stricter than Japan’s regulations. Russian experts themselves now admit
that this was a mistake and failed to protect the people. Many residents
who had no need to evacuate were forced to evacuate, and as a result, they
suffered harmful adverse effects in addition to their exposure to radiation,
resulting in a seven-year decrease in the population’s average life expectancy.
People lost their will to live and their pride when sudden changes in their lives
brought on unemployment and austerity. Alcoholism rose, many became
depressed, and some even committed suicide because of this. Psychological
anguish and stress increased the risk of mortality.
I understand that people may feel anxious about living every day in an area
that is called a hot spot. However, the levels that are being detected right
now will cause no problems. It is wiser to think that evacuation would pose a
greater risk.
Question: They say that 3200 becquerels/kg, six times the national regulatory standard of 500 becquerels/kg, was detected in beef from cows that ate contaminated rice straw. What would happen if I ate that?
Answer: If you are served and eat a 200 g steak made from this beef, the
exposure would be 0.01 mSv; this is not a dose at which you should worry
about the effects on your health.
Starting in April 2012, Japan’s national regulatory restrictions will become
111110
harmful things into their bodies. Minamata disease, the starting point of
Japanese environmental pollution awareness, was caused by accumulation of
a heavy metal in the human body in high doses, because people are high in
the food chain. More recently, pathogenic Escherichia coli 0-157 and BSE (mad
cow disease) have been in the news. Both were caused by putting harmful
things into the body. These problems in the past have heightened people’s
present awareness regarding food safety.
I think that the almost excessive anxiety in response to internal exposure
to radiation has this as a backdrop. However, radioactive substances are
different from heavy metals and are discharged eventually from the body
through excretion and one’s metabolism. I should also add that radiation
weakens over time.
Let me add finally that when people make sensational remarks, various
motives can be at work behind the scenes. The claimants may have a conflict
of interest when, for example, they warn you about internal radiation
exposure and also coincidentally sell supplements that, they claim, protect
you against this exposure. The best protection is to have access to the most
reliable possible information.
People in rural areas and people in the metropolis, survivors of the disaster,
producers, and consumers all have differing points of view, but the most
important thing is that they share a correct understanding and knowledge. I
want people to know that Japanese food safety standards are already strict as
they are, and they will become even stricter.
I understand that the people of Fukushima are in a terrible predicament now.
Furthermore, Fukushima’s most important industry, agriculture, is facing a
major crisis because, beginning in April, the regulatory limits for radiation
in food will become 1/5 what they were. In other words, annual exposure
limits are going to be lowered from 5 mSv to 1 mSv. This will certainly hit the
producers hardest.
It takes a certain period of time for radiation that has been emitted to
disappear. I hope that there will be generous compensation for producers.
From the consumers’ standpoint, however, the fact that food regulations will
become even stricter means that no one should have any worries when they
eat agricultural products that are available on the market.
I cannot help but feel that someone who, safe and secure in Tokyo, makes
a commotion about dangers where the risks are low is causing needless
suffering for the people of Fukushima.
Assertion: “Internal exposure to radiation is 600 times more dangerous than external exposure.”
Response: I have no idea where the scientific proof for this statement is.
Cesium, an alkali metal, is similar to potassium, and like potassium, when it is
taken into the body it is distributed almost evenly throughout the body. This
has been confirmed by analysis of cows in Fukushima Prefecture that ran wild
and were put down. Because cesium is distributed very evenly throughout
the body, internal exposure to radiation emitted by cesium does not collect
in or affect any particular organ; it is almost the same as exposure to external
radiation, which affects every part of the body equally.
I therefore do not think there is a difference between internal and external
exposures to radiation. 1 mSv of exposure has the same effect on the human
body, whether the exposure is internal or external. I have seen the claims
made by some ECRR scholars, but I think that they do this just to scare people.
However, psychologically speaking, people do feel anxious about putting
113112
Tokyo consumed and consumes especially large amounts of electric power,
so now is the time to support Fukushima in return. I touched on the subject
of accepting Fukushima’s debris in this book. This is one of the few things
that we who live far away from Fukushima can do, in however modest a
fashion, to share the hurt of the people of Fukushima.
This great metropolis with its dazzlingly bright lights, lit up throughout
the night and consuming vast quantities of electricity, is a symbol of the
modernization that mankind has achieved. Yet even with the world’s highest
technology, we cannot reduce the half-lives of Cesium-137 (30 years) and
Uranium-238 -- a mind-boggling 4.5 billion years. Even worse, because men
have created substances such as plutonium and strontium that never existed
in nature, we are polluting the natural environment with elements beyond
our control, and as a result, we, too, must now lead insecure lives.
I see so much palpable arrogance in this destructive behavior, because we
human beings are but one species among multitudes inhabiting planet Earth.
May this accident be a chance for us to reexamine our own mode of existence
with humility and to rethink our approaches to how things (including energy
problems) ought to be dealt with in modern society. Japan is a country
surrounded by the sea on all four sides; it has four enjoyable seasons of the
year and plentiful forests and water all year round. The Japanese have lived
for thousands of years blessed by the seas and mountains that surround it.
Fukushima, with its abundant harvests of vegetables, fruit, and seafood, was
a prefecture that typified the generosity of Japan’s natural endowments. For
many, many years to come, the national government and TEPCO must make
amends for their horrible crime of polluting such beautiful lands and waters,
forcing tens of thousands of residents to move far away from their homes.
The path ahead of us is long and will be filled with hardships. However,
eventually, in one way or another, we will recover. My reasoning behind this
certainty, as I have repeatedly stated in this book, is that, after Hiroshima and
Nagasaki, Japan rose up and became the prosperous nation it is today. Even
more surprising, Hiroshima is now the city with the longest life expectancy
in Japan (which has the highest life expectancy in the world). Fukushima
Prefecture, by coming to terms with the facts of radiation and taking
appropriate actions, will someday have the highest life expectancy in Japan. I
Ever since the nuclear accident caused by the Great East Japan Earthquake
on March 11, 2011, we have had to face serious problems, one after another,
problems we have never faced before.
The first was the risk of cancer from exposure to radioactive substances
leaking from the nuclear power plant. This probably is what most people
were most worried about. Here I have tried to explain from my standpoint as
a radiologist in a way that is as easy to understand as possible the connection
between exposure to radiation and the mechanism of cancer’s occurrence.
This nuclear accident created other problems as well. They include the
psychological and economic damage resulting from living for months
and years in evacuation centers and from malicious rumors, as well as
the aftereffects of being bombarded with conflicting reports and more
information than anyone can normally deal with, situations which cause the
affected populations immense anxiety and severe mental anguish.
When I saw this situation arising, I felt strongly, more strongly than I had ever
before, how immoral it is that nuclear accidents are allowed to occur and
how I must now assume fully my duty and role as a radiologist. I needed to
communicate the facts properly in the light of the current situation, as an
expert and as fully as possible. This was how this book came to be published.
I will never say to people: “You have nothing to fear: don’t run away.” I
understand very well parents’ feelings when they worry about their very
young children: they will obviously choose to do what is best for their
families. Ever since the nuclear accident, we have been faced with unusually
hard decisions affecting our everyday lives. This will probably continue for
some while. My hope is that this book will help readers understand their
options if they are placed in a situation where they must make such difficult
choices.
When looking back once again at that nuclear accident, I am assailed by a
welter of thoughts. Tokyo Electric Power Company (TEPCO)’s Fukushima
Daiichi Nuclear Power Plant provided electricity mostly to the Tokyo
metropolitan area. In other words, the nuclear power plant in Fukushima
provided us here in Tokyo with the electricity we needed to live in comfort for
decades. We must never forget this.
In Conclusion
114
firmly believe this.
December 2011
Keiichi Nakagawa