radiation safety for ancillary employees

ONLINE SELF-STUDY

Radiation Safety for Ancillary Employees

In this course, you will learn about:

Radioactivity and Radiation

Radiation Units and Terms

Background Radiation

Radioactive Materials

Signs and Labels

Radiation Risk Assessment

Radiation Protection at UNC

Radiation Safety Practices – ALARA

Basic Radiation Safety Procedures

Dose Limits and Monitoring Requirements

Guidelines for Working Safely Around Radiation Sources

Important Contact Information

DID YOU KNOW?

Wilhelm Conrad Roentgen

Discovered X-Rays in 1895

What is radiation?

Radiation is the transfer of energy

This course deals with ionizing radiation Radiation that creates ions X-rays, gamma rays, beta particles, neutrons

Comes from different sources: Unstable atoms Electrically or machine produced


Radiation is beneficial in medicine and research

Allows for the imaging, diagnosis, and treatment of internal structures and diseases

Uses at UNC-- X-ray machines

Radiopharmaceuticals

Linear accelerators and sealed sources

Research Labs


Radiation can not be seen, felt, smelled or tasted!

It can however be measured!

Terms used to describe radiation and radioactive materials:

Exposure (R – Roentgen)

Electrical charge per unit mass of air produced by x or gamma rays

Absorbed Dose (RAD – Radiation Absorbed Dose)

Amount of energy per unit mass absorbed by an irradiated object


Dose Equivalent (REM – Roentgen Equivalent Man)

Modified absorbed dose

Regulatory dose reporting unit

Takes into account the biological impact of

the radiation (i.e. beta particle, x-ray, neutron)

Note: 1,000 (millirem) = 1 rem

Activity (Ci – Curie)

Nuclear transformations per unit of time

Amount of radioactivity of a nuclide

DID YOU KNOW?

Marie and Pierre Curie

Discovered Radium in 1898


We are all exposed to radiation everyday!

Naturally-occurring in our soil, air, and water

Even our bodies contain natural radioactivity!


Average US resident receives about 600 millirem per year from naturally-

occurring and man-made sources of radiation

Equivalent to ~20 chest x-ray procedures

Half comes from naturally-occurring sources of radiation:

Largest contributor is Radon

Half is from man-made sources such as:

Computed Tomography (CT)

Nuclear Medicine


Diagnostic Radiopharmaceuticals (Tc-99m, F-18, Tl-201, I-131, and I-125)

Used in Nuclear Medicine and at the Biomedical Research Imaging Center

Emit penetrating gamma rays

Remain in the subject after the study

Have short half-lives (so subject and others are not exposed for long periods)

Negligible radiation hazard from these individuals

No “special” precautions in caring for these individuals

Practice universal precautions

No restrictions on subject activities or contact with other people



Radionuclides used in clinical labs emit beta particles and gamma rays

Beta particles are not as penetrating as gamma rays or x-rays

Weak/moderate energy betas will not penetrate the skin

Keep radioactive materials from contaminating the skin and work areas

Contaminated skin may lead to ingestion/absorption and spread of material

Because radiation cannot be seen or felt, the radiation symbol (“tri-foil”) is used to alert you to its presence

Posting for containers of radioactive

material and rooms where radioactive

materials are stored or used

Posting for rooms or areas where

radiation-producing equipment is used

Signs and Labels

Although radiation can be of benefit, too much can be dangerous

Two types of ionizing radiation effects

Effects occurring given enough dose

Threshold effects such as cataracts and erythema

Effects with a higher chance of occurring as dose increases

“Chance” effects such as cancer, genetic mutations, and effects on the embryo/fetus

Radiation dose effects

Large-dose effects are well-documented and understood

Low-dose radiation effects are not so well understood


The important thing to remember is the perception of risk vs. the reality

Many think of radiation based upon what they have seen in the movies

This FICTION is their PERCEPTION

The reality is the risks from radiation are quite low

For example, the risk of getting cancer from 10 millirem of radiation is roughly equivalent to the chance of winning the lottery by buying only one ticket


It is also important to realize that standards and regulations for your job keep the chance of undesirable effects quite low

Workers of UNC are in general exposed to low doses of radiation

Risks from radiation exposure are comparable to risks from other “safe” professions

You may also be exposed to x-rays as a patient (not occupational)

Calculate your own dose and risk from medical exposure to x-rays at http://xrayrisk.com/.


http://xrayrisk.com/

UNC-Chapel Hill Department of Environment, Health & Safety Radiation Safety

Section

Acts as an “agent” for the Radiation Safety Committee

Manages the University’s radiation protection program

Obtain radiation safety information from the Radiation Safety Officer (RSO) at

919-962-5507

Click here for Radiation Safety’s website: UNC Radiation Safety


http://ehs.unc.edu/radiation/

Radioactive materials used under a “broad medical license”

Issued by the Department of Health and Human Services

North Carolina Radiation Protection Section (NCRPS)Visit their website at: NC Radiation Protection

X-ray machines are licensed or registered with the NCRPS

Radiation Safety Committee

Oversees and approves ALL use of radioactive materials and radiation-producing

equipment

NCRPS "Notice to Employees" form

Contains important information

Posted where radiation sources are used


http://www.ncradiation.net/

NC Regulations require we have an ALARA program

Ensures radiation exposures are maintained As Low As Reasonably Achievable

ALARA assumes any radiation dose, no matter how small, can have some adverse

effect

-Shoe store fluoroscopes such as this one

from the early 1900s were outlawed-

They are not ALARA!

Radiation Safety Practices - ALARA

Minimize radiation exposure by utilizing three basic principles:

Time, Distance and Shielding

Radiation Safety Practices - ALARA

Radioactive Spills:

Do not clean up unless trained in radiological response

Remember, small droplets may splash away from the spill

Contain running liquids with a paper towel or other absorbent material

Isolate the area and notify the Radiation Safety Officer

Monitor all persons involved in a spill for contamination

Basic Radiation Safety Procedures

NC Regulations For Protection Against Radiation

Dictate the amount of radiation a person may occupationally receive

15A NCAC 11 Annual Dose Limits for Monitored Radiation Workers:

Whole Body: 5,000 millirem

Skin/Extremities: 50,000 millirem

Lens of Eye: 15,000 milliremA worker is required to be monitored if likely to exceed 10% of the above limits

General public (non-radiation worker, this is you)

Allowed 100 millirem per year

-DID YOU KNOW?-

The first US dose limit set in 1957

was 300 millirem/week!

Dose Limits and Monitoring Requirements

RADIATION-PRODUCTING EQUIPMENT

External Exposure Only

Hazard present ONLY when equipment “ON”

Authorized operator present whenever equipment “ON”

Enter only those areas you are authorized and trained to enter

Rooms adequately shielded for protection

Avoid immediate work/use area if possible

ASK personnel in area and stay alert

Guidelines for Working Safely Around

Radiation Sources

RADIOACTIVE MATERIALS

External exposure and contamination hazards (both external and internal)

Hazard present when materials not shielded or contained

Research subjects may also be radioactive

Radioactive materials should be secured at all times

Look for warning labels (including radioactive waste)

ASK personnel in area and stay alert

Know procedures for contamination incidents & spills

Food & drink only in designated areas

Guidelines for Working Safely Around

Radiation Sources

Report unusual or unsafe conditions

involving sources of radiation to the

Radiation Safety Office immediately

Radiation Safety is available during normal

working hours at 919-962-5507

Radiation Safety can be reached after

normal working hours through Campus

Police at 919-962-6565 or 911 (from

campus/hospital phone)

Radioactive Materials licenses, x-ray registrations, regulations, inspection reports and exposure reports are available for review in the UNC Department of Environment,

Health and Safety, Radiation Safety Section

1120 Estes Drive Extension, CB# 1650

Important Contact Information

radiation safety for ancillary employees

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