Chapter 19Chapter 19AIR POLLUTIONAIR POLLUTION

YOUR RESPONSIBILITY…YOUR RESPONSIBILITY…Pages Pages 438 - 441,438 - 441,

447 - 452447 - 452452 - 457,452 - 457,483 - 484483 - 484READING QUIZ!!!

Atmosphere as a Resource

• Composition:– Nitrogen (78.08%)– Oxygen (20.95%)– Argon (0.93%)– Carbon Dioxide (0.04%)

• 2 most important to living organisms:– CO2 and O2 (photosynthesis & respiration)

• N2 also important (N2 cycle)

• Ecosystem Services– UV filter, moderating climate, redistributing water

Types and Sources of Air Pollution

Air Pollution = gases, liquids, or solids present in the atmosphere in high enough levels to harm humans, other organisms, or materials.

• Natural pollution (lightning causes forest fires, volcanic eruptions)

• Human-induced pollution (ANTHROPOGENIC)– Harmful for 2 reasons:

• They precipitate & settle on Earth• They alter the chemistry of the atmosphere

– Much of the air pollution released by humans is concentrated in densely populated urban areas

Primary Air Pollutants• Harmful chemicals that

enter directly into the atmosphere

• EX: carbon oxides, nitrogen oxides, sulfur dioxide, particulate matter, and hydrocarbons

Secondary Air Pollutants• harmful chemicals that form

from other substances that have been released into the atmosphere.

• EX: ozone & sulfur trioxide

Primary Air Pollutants and Sources

Effects of Air PollutionClass Discussion

Air Pollution & Human HealthAir Pollution & Human Health

• Exposure to Low Levels causes…– Eye irritation– Inflammation of the respiratory tract– Immune system suppression– Development of emphysema & chronic bronchitis

Health Effects of Health Effects of Specific Air PollutantsSpecific Air Pollutants

QUESTION: Why are people who live & work in QUESTION: Why are people who live & work in the country’s most polluted cities 15-17% more the country’s most polluted cities 15-17% more likely to die prematurely than those living in US likely to die prematurely than those living in US

cities with the cleanest air?cities with the cleanest air?

ANSWER: ANSWER:

Exposure to Sulfur Dioxides (SOExposure to Sulfur Dioxides (SOxx), ),

Nitrogen Oxides (NONitrogen Oxides (NOxx, N, N22O), O),

Carbon Dioxide (COCarbon Dioxide (CO22), Ozone (O), Ozone (O33), ),

Particulate & VOC’sParticulate & VOC’s

SO2 & Particulate Matter•Produced as part of the coal combustion process & industry

•Travels long distances from source.

•SO2 reacts with H2O vapor and forms sulfuric acid ACID RAIN!ACID RAIN!

•Sulfate particles + nitrogen oxide create small particles or

particulates which have detrimental health effects including:

1. Respiratory tract irritation

2. Decrease in lung’s ability to exchange gases

3. Airway constriction

4. Increased sensitivity to pollen and dust mites

5. Leach nutrients from soil

Vulnerable Ecosystems: Lakes, Streams, Forests, High Elevations

Nitrogen Oxides (NOx)• Nitrogen oxides are formed from

atmospheric nitrogen when coal and otherfuels are burned.

• Ways to reduce the amount of NOx produced include catalytic

converters on cars and low-NOx burners on power plants.

• Interact with sunlight and other molecules to produce ground level ozone.

• Health effects include:1. Asthma among children2. Airway constriction3. Increased sensitivity to

pollen and dust mites4. Acid rain & atmospheric haze (photochemical smog)

Vulnerable Ecosystems: Lakes, Steams, Forests, High Elevations

CARBON DIOXIDE

• Formed when fuels are burned- Coal has highest content.

• Big greenhouse gas responsible for global warming.

• CO binds irreversibly with iron in the blood’s hemoglobin, eliminating its ability to transport O2 (asphyxiation)

• Health Effects include: 1. Linked to the spread of infectious disease, higher ozone levels,

increased heat & cold related illnesses

2.Medium Concentrations: causes headaches & fatigueHigher Concentrations: slower reflexes & drowsinessVery High Concentrations: death

3.Greatest risk: pregnant women, infants, those with heart or respiratory diseases.

Ecosystem effects: Rising sea levels, increased disease, larger storms, extinction of sensitive

species.

Ozone & VOC’sProduced when nitrogen oxides

react with volatitle organic compounds (VOC) in the presence

of sunlight.

•Health problems include:

1. Irritants: burning eyes, coughing, chest discomfort

2. Asthma attacks, immune system suppression

3. Pregnant women exposed to high levels of O3 and CO are 3X more likely to give birth to infants with serious heart defects.

4. Plant damage at low concentrations

Vulnerable Populations: Children, elderly those with respiratory disease, those who exercise outside.

Pollutants from Motor Vehicles, businesses &

IndustryLong-term exposure is linked to

cancer (although the risk is rather low compared to others like

smoking)

Some Health Effects of Air Pollution Nationwide

Mortality: 23,600 Hospital Admissions: 21,850

Emergency Room Visits for Asthma: 26,000 Heart Attacks: 38,200

Chronic Bronchitis: 16,200 Asthma Attacks: 554,000

DON’T WRITE THESE….

Just some statistics for ya

PHOTOCHEMCIAL SMOG

Nox + VOC O3

PARTICULATE

MATTER

smoke detector

filters

sticky materials

N & S & C OXIDES

devices /

equipment

CO detector

chemical tests

AIR TOXICS

mold tests & filters

radon detectors

OZONE

Schoenbien

papers

chemical tests

indirect

evidence

(plant growth,

etc)

ozone action

days

HYDROCAR

BONS

devices /

equipment

ACID DEPOSITION

pH tests

indirect evidence

Children and Air PollutionChildren and Air Pollution

• Air pollution is a greater health threat to children than adults.

• Restricts lung development• Causes early stages of lung disease

• Children have higher metabolic rates than adults• they breathe ~2X as much air per pound of body weight

• Studies show that children who move to areas with…

• less particulate matter have increased lung development.• more particulate matter have decreased lung development

GOOD NEWS:

• Fewer people in highly developed nations smoke.• Cigarette production in the US is down• Smoking decline in Japan & most European countries

BAD NEWS:

• More smokers in China, Brazil,

Pakistan, and other developing nations.• Some nations: smoking habit = 20% of a worker’s annual income• Sales in developing countries has increased 80% since 1990.• US tobacco companies promote smoking abroad, and we export

much of our tobacco.• 3M people die each year of smoking-related causes worldwide.• US: some minority groups & those with the least education have

high numbers of tobacco addicts• More than 1M US children & teens take up smoking every year.

Smog…Air pollution that is localized in urban areas

where it reduces visibility

1. Industrial Smog: aka: smoke pollution

principal pollutants are sulfur oxides and particulate matter. Worse in the winter months because of heating needs.

Composition of Composition of Photochemical SmogPhotochemical Smog

REVIEW…. What causes smog?

More people means more fuel!

Fossil fuel combustion creates NOx and VOCs (reactants)

Sunlight is the energy catalyst for the reaction.

Precipitation cleans the air, and winds disperse the smog.

Topography and Air PollutionUnder normal conditions, air circulation patterns

prevent toxic pollutants from increasing to dangerous levels near the ground.

That is not the case in this

picture of LA….

What do you think is causing this to happen?

Temperature InversionsTemperature Inversions

AKA: Thermal Inversions

Air near the ground is cooler than the

air at higher levels and the

polluting gases/particulate

matter remain trapped in high concentrations

near the ground.

Los Angeles• Located between coast and mountains• Sunny climate produces a layer of warm dry air at higher elevations• Upwelling in the ocean produces cool ocean air• As cool air blows inland, the mountains block movement further and

layer of warm dry air overlies cool air at the surface… Temp inversion!!

Think back to the Global Winds... how does this

relate??HINT:

Where is LA

Longitudinally?

Urban Heat Island: air in urban areas is warmer than the air in the surrounding suburban and

rural areas.Affects local air currents and weather conditions.

Q: Why do they increase the number of thunderstorms???

Urban Heat Islands & Dust Domes

Dust Domes: buildup of pollutants, especially particulate matter over cities.

Convection of air lifts pollutants into the air where they remain because of somewhat stable air masses produced by urban heat

island

CONTROLLING AIR POLLUTANTSRead pages 446- 447 in Raven & Berg and write a paragraph about

how scrubbers and electrostatic precipitators remove pollutants from factory exhaust.

HOMEWORK/CLASSWORK…..HOMEWORK/CLASSWORK…..Read and understand page 447-452

Key points to KNOW:

- Clean Air Act 1970

- Changes to the Clean Air Act (1997)

- Ways to improve air quality

- CASE IN POINT: Los Angeles

- Meeting the challenge: clean cars, clean fuels

- Pollution in developing Countries

- CASE IN POINT: Mexico City

…homework will be checked in one way or another….

HINT…HINT...HINT…HINT…HINT…HINT...HINT…HINT

LINK TO

DIISCUSSION SLIDES

Developing Countries & Energy ~Richard Spencer, The Daily Telegraph, from Beijing:

“…Here comes the man with the coal bricks we residents all use to fire the boilers of our homes... Not cold enough for the central heating yet? You're

right, but there's a discount - the earlier you buy, the cheaper it is.”

Global Distillation Effect- volatile chemicals evaporate from land as far away as the

tropics and are transported by winds to higher latitudes where they condense and fall to the ground

Certain hazardous air pollutants are distributed globally by atmospheric

transport

PCB’s & DDT are both persistent chemicals that do not readily

break down and accumulate in the environment.

They are still used in developing countries and move through the

atmosphere to developed nations where they are deposited on land

and surface water.

Global Distillation Effect cont…• Dangerous level of persistent toxic

compounds have been measured in the Yukon

• Chemicals enter food webs and become concentrated in the body fat of animals

Inuit eat the animals

And the concentration

of chemicals increases

in their system causing

problems for their

Health.

Why does this happen to Canada?

What can we do to stop this problem?

What can the US do to stop Canadian smog

problem?

Should we help alleviate the smog problem?

Are we?

Why is science involved in foreign relations?

Il, IN, MI, OH, PA, TN & WV produce 50-75% of the acid

deposition that contaminates New England and Canada

Stockholm Convention of Persistent Organic Pollutants (2001)

Goal: phase out the use of 12 persistent toxic chemicals

Countries: Canada, US, Russia, Finland, Norway, Sweden, Denmark, Iceland

Indoor Air Pollution

How Radon Infiltrates a House

ACID DEPOSITION• Acid deposition (rain, sleet, snow and fog) is a

type of air pollution• Sulfuric acid & Nitric acids

Estimated cost to the US is $10 Billion/yr

• Wet Deposition: – Sulfuric and nitric acids in

precipitation

• Dry Deposition: – Sulfuric acid and nitric acid

containing particles that settle out of the air.

End of Ch 20

The pH scale measures the

amount of H+ ions present in the

solution.

A pH of 6 is 10x more acidic than a

pH of 7.

Normal rain has a pH of ~ 5-6 because CO2 in the air dissolve in

rainwater forming dilute acids. Acid rain

= 3-4

Acid deposition occurs when sulfur dioxide and nitrogen oxides are released into the

atmosphere. Sources: Cars, Coal burning power plants, smelters,

industrial boilers

Effects: SO2 and NO react with water to produce dilute solutions of H2SO4, HNO3, HNO2

• Effects of Acid Deposition– Corrodes metals and building materials

Affects Animal populations (Adirondacks)• 1,469 lakes examined,

325 found with pH <5

• Birds with thin fragile shells (lack of Ca due to acidic soils)

–Forest DeclineCharacterized by gradual

deterioration and eventual

death of trees.

- Black forest of Germany

50% of trees dead

-MOUNT MITCHELL, NC

Results from a combination of multiple stressors (acid deposition, tropospheric O3, UV radiation, insect attack, drought, etc.)

Soil ChemistryCa & K wash readily

out of acidic soil where others (N)

become available in large amounts

Heavy metals dissolve in acidic soil becoming available

for absorption in toxic amounts.

Links between GW, Ozone Depletion & Acid Deposition

• Global warming, ozone depletion and acid deposition interact

• Combined effects of acid deposition and climate warming make North American lakes more susceptible to damage from UV radiation caused by the thinning of the ozone layer.

READ PAGES 483-484…. The book says it best!!!

Is the Clean Air Act working?

What does this cartoon tell you about the United

States air quality in 2002?

Is this a fair representation?

Is there bias? If so, WHAT???

What can we do to avoid this

type of situation?

Sources of smog in Los Angeles

What would happen to California’s smog if 20 of

every 100 cars was a hybrid?

Do you think that it is alright for the government to restrict

car companies from producing polluting cars?

Should tax incentives be given to those who purchase

fuel economic vehicles?

Would it be fair to impose a tax on vehicles that do not

burn fuel efficiently?

Discussion points of the HOMEWORK…