RADIATIONIN THE WORK

PLACE

Presented by: Ali Shoushtarian

Office of Risk Management, Environmental Health and Safety Service

June, 2007

Topics

• What is Atom?• What is Ionizing Radiation?• What is some specific non-ionizing Radiation?

1. X-ray

2. Laser

• What you should do before working?

• How to protect yourself

Manager, Radiation and Biosafety• Lois Sowden-Plunkett• ext. 3058

lsowden@uottawa.ca

Radiation Compliance Specialist• Ali Shoushtarian• ext. 3057

ashousht@uottawa.ca

Radiation Safety Program Web Page http://www.uottawa.ca/services/ehss/ionizing.htm

REGULATORY AGENCIES

• Canadian Nuclear Safety Commission (CNSC) • Regional Municipality of Ottawa Carleton• Ontario Fire Marshall• Transport Canada• Ontario Ministry of Labour

STAKEHOLDERS

• Radiation Safety Committee• ORM• PRS• Contractors

THE ATOM

• All physical matter in our world is made up of what are called ATOM.

ISOTOPES

• Atoms with the same number of protons but different numbers of neutrons are different isotopes of the same element.

                                                                                       

RADIOACTIVE ISOTOPES

• In an Unstable atom, the nuclear forces are not strong enough to hold the nucleus of the atom together

• Unstable atoms want to be become stable!

• While becoming stable, Unstable atoms emit radiation.

Signage

• Signage on the door… what does it mean

• Sources of information– Supervisor, ORM

What Is Radiation

• Spontaneous decay• Half-life• Cosmic• Terrestrial• X-ray• Microwave

RADIATION• Cosmic: altitude and latitude

• Terrestrial: geographically

• Food (pCi): brazil nuts; cereals; teas; liver and kidney; flours; peanut butter; chocolates; biscuits; cheese; vegetables

MAN-MADE RADIATION

• Medical x-rays: 770 Sv/yr

• Fall-out from weapons testing: 40 Sv/yr

• Consumer products: 10 Sv/yr

• NATURAL BACKGROUND: 800 Sv/yr

RADIATION EMISSION

• ALPHA: neutron and proton; 2-8 cm in air

• BETA: negatron and positron; 0-10 m in air

• GAMMA: electromagnetic radiation; 100 m in air

• X-RAYS: electromagnetic radiation; 100 m in air

EXTERNAL DOSE

Alpha particles

Beta particlesGamma rays

COMPARISON OF RISK

• exposure to 0.1 mSv ionizing radiation (1/10th annual ionizing radiation that a person in a lab receives)

• smoking 1.5 cigarettes

• travelling 50 miles by car

• being male and 60 years old for 20 minutes

• canoeing for 6 minutes

TIME

D = d x t

D = radiation dose

d = radiation dose rate

t = time duration of exposure

DISTANCE

Inverse Square Law

D1 s12 = D2 s 2

2

D1 = dose at distance 1

s1 = distance 1

D2 = dose at distance 2

s 2 = distance 2

SHIELDING

• Reduces or stops radiation

• Dependent on:

- energy of radiation

- type of shielding

X-RAY

Like radioactivity, X-rays are energy released from anunstable atom. •Most X-rays are produced by specially designed equipment

X-RAY

General X-Ray Safety Precautions

•This equipment must be “on” to generate X-ray

•Interlocks are a set of switches in a series, where EVERY switch must be closed in order for the X-rays to be generated .If any switch is opened, the X-ray generator will immediately shut off .

•A sign or label bearing the words "CAUTION -RADIATION, THIS EQUIPMENT PRODUCES X-RADIATION WHEN ENERGIZED" or words having similar intent, is near switch which energizes an X-ray tube.

There must be a warning light that illuminates when the x-ray tube is on. This light is adjacent to the x-ray tube or housing or port.

If you have any question, please call our office at ext. 3057 and we will assist you with the safety question that you may have.

X-RAY

Laser

• A laser is a device that emits a thin beam of either visible or invisible electromagnetic radiation (light)• Light Amplification by Stimulated Emission of Radiation (LASER)• The Laser must be on to generate Laser beam.• Different classes has different hazard• Therefore, different controls measures required

Laser Classifications• Class 1: "safe" if not disassembled. Example: Laser printers,

CD-Rom players/drives • Class 2: may exceed class 1 exposure limits if viewed more

than 0.25 seconds , but still not pose a significant eye hazards. Example: Supermarket scanners

• Class 3A: eye hazard if viewed using collecting optics, e.g., telescopes, microscopes, or binoculars.

• Class 3B: eye hazards if beams are viewed directly. Example: research

• Class 4: eye hazards if beams are viewed directly and sometimes even from diffuse reflections are viewed. Also skin burns from direct beam exposure.  Example: research, manufacturing.

Laser

Laser

Class 3B

Class 4

Class 3A

Laser Pointers

1. The use of laser pointers has become widespread. The pointers are useful tools for educators in the classroom and at conventions and meetings.

2. The hazards of laser pointers are limited to the eye 3. The most likely effects from exposure to viewing the beam from a laser pointer are

afterimage, flash blindness and glare

Laser Pointers Tips

• Never shine a laser pointer at anyone. • Do not allow minors to use a pointer unsupervised. • Do not point a laser pointer at mirror-like surfaces. A reflected beam can act like a

direct beam on the eye.• Do not purchase a laser pointer if it does not have a caution or danger sticker on it

identifying its class. Report suspicious devices to the ORM.

Laser

General Laser Safety Precautions

• Always use proper laser eye protection. • The device must be turned on to present a risk• Only properly trained & authorized personnel should

operate the laser. • Make sure the laser is off before entering the designated

area

• If you have any question, please call our office at ext. 3057 and we will assist you with the safety question that you may have.

Laser

What you should do before working?

• Laboratories are safe to enter. But just because they are safe doesn't mean that you don't have to be careful.

• Make sure you obey all warning signs. • Do not enter labs with x-ray or laser lights on. • Do not enter labs where alarms are sounding. • Obtain authorization to enter lab either by supervisor

or lab personal

What you should do before working?Custodians• Don’t touch anything with a ionizing radiation, non ionizing radiation (X-

ray and Laser Class 3 or higher) or biohazard symbol on it. • Never clean spills in the lab unless the spill is from your cleaning

materials. (even if you made the spill). • Do not touch or remove contaminated glass. • Wear safety glasses or goggles at all times in the lab.

Mechanics/Plumber• Inform the lab supervisor before doing any work. • The lab supervisor is responsible for ensuring your work area is free from

hazards. • Do not touch or move anything with ionizing or non-ionizing radiation

symbol on it. • Wear safety glasses or goggles at all times

HOW TO PROTECT YOURSELF:EXTERNAL RADIATION

• Decrease time

• Increase distance

• Use shielding

• As Low As Reasonably Achievable (ALARA)

HOW TO PROTECT YOURSELF:INTERNAL RADIATION

• Prevent:– ingestion– absorption

• X-ray can damage your skin. For example, consider exposure to sunlight. The severity of the detrimental effect (the sunburn in this example) is determined by amount of exposure.

• These are long term effects, which do not show in the exposed population until many years after the exposure.

How do you know if you are Exposed

The principal danger from lasers is to the eye. The primary region of concern for low power visible lasers is the retina of the eye.

Laser Effect• Afterimage: The perception of light, dark, or colored spots after exposure to

a bright light that may be distracting or disruptive. Afterimages may persist for several minutes.

• Flash-blindness: A temporary vision impairment that interferes with the ability to detect or resolve a visual target following exposure to a bright light.

• Glare: A reduction or total loss of visibility, such as that produced by an intense light source, such as oncoming headlights, in the central field of vision.

What should I do if I am flashed in the eyes with a laser pointer?

As soon as you are aware of the laser, look away from the laser beam or close your eyes, and move out of its way.

How do you know if you are Exposed

How do you know if you are contaminated

• Radiation cannot be seen, smelled, felt, or tasted, people at the site of an incident will not know whether radioactive materials were involved.

• You can ask the lab personnel to use a contamination meter to see whether or not you are contaminated with radioactive material.

If you become contaminated; you can take the following steps to limit the spread of the radioactive material.

1. Remove the outer layer of your clothing. If radioactive material is on your clothes, getting it away from you will reduce the external contamination and decrease the risk of internal contamination. It will also reduce the length of time that you are exposed to radiation.

2. If possible, place the clothing in a plastic bag. Keep people away from it to reduce their exposure to radiation. Keep cuts and abrasions covered when handling contaminated items to avoid getting radioactive material in them.

3. Wash all of the exposed parts of your body using lots of soap and lukewarm water to remove contamination. This process is called decontamination. Try to avoid spreading contamination to parts of the body that may not be contaminated, such as areas that were clothed.

PERSONAL DECONTAMINATION

• Use tepid water and mild soap.• Avoid causing abrasions to skin.• Wash for a few minutes, dry and monitor. • Carefully monitoring is the only way to measure

progress.• Numerous gentle washes are superior to one rigorous

one.

HOW DO WE PROTECT OURSELVES?

• PPE: gloves, lab coat, overall, eyeglasses

• Secondary Container, minimize spills

• Dedicated tools

• Wash hands

HOW DO WE PREVENT THE POSSIBILITY OF THIS SITUATION FROM HAPPENING AGAIN?

• Ask why did it happen?

– Regular maintenance

– Use Common Sense

SUMMARY

General Precautions

• Avoid direct contact• Minimize exposure time• Wear appropriate protection• Wash your hands frequently• Do not eat or drink

General Procedures• Specific procedures may apply to hazardous

materials. Ensure you verify with your supervisor.

• Do not move, handle or dispose of any material labeled with radioactive symbols.

• Report any Concerns immediately to protection Services

(562-5411)

• If in doubt, verify with your supervisor or protection services