Describe the Perspective Clothing That Should Be Worn for the Lab Staff Working in a Lab With Radioactive Elements

8/9/2019 Describe the Perspective Clothing That Should Be Worn for the Lab Staff Working in a Lab With Radioactive Elements

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1. Describe the perspective clothing that should be worn for the lab staff

working in a lab with radioactive elements.

Radioactive elements can come from variety of source in laboratory and

hospitals. The chemical, instruments and natural occurring radioactive elements

always present in our daily lives. The types of radiation can either be x -ray, gamma

ray, alpha particles, beta particles and neutron. Therefore, it is important to wear a

protective gear when handling all this radiation to prevent dam age or mutation on our

cell that can cause diseases.

Use of radiation shielding is highly effective in intercepting and reducing

exposure from scattered radiation. The staff should realize radiation exposure

reductions of more than 90 percent through the correct use of any of the following

shielding options. Shields are most effective when placed as near to the radiation

scatter source as possible. One of the personal protective equipments is lead

aprons. The lead aprons should be wearing when using x -ray on patient. It contains

lead and often other materials such as tin, tungsten, antimony or barium that protect

the body from radiation. These metals are homogeneously mixed with synthetic

rubber or polyvinyl chloride (PVC). Between two and five thin sheets o f metal-

impregnated rubber/PVC are placed between sheets of nylon fabric coated with

urethane on the side against the lead-impregnated rubber/vinyl. The materials are

cut into a pattern and sewn together to form the protective garment. The

manufacturers of these garments vary the number of sheets, the percentage of

metal, the grade of rubber or PVC, and the mixture of metals to affect flexibility,

durability, radiation absorption efficiency, and weight (cited from Reducing Radiation

Exposure). Although it is useful, the apron does not protect all the radiation. At least

80% reduction is obtained when wearing the apron. The most common and new

apron suggested for lab workers are two piece lead apron system because it

provides wrap-around protection and distri bute the weight more evenly on the user.


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The face also required protection from the radiation. A safety helmet (bump

cap) may be worn when wearing enclosed suits or hoods. Other part of face

necessary for protection is a respiratory. There are 2 categories of Respiratory

Protective Equipment with several subdivisions in each category

I. Respirators purify the air by filtering out particulate materials such as

dust or low concentrations of gas or vapour. The most common types

are:

(A) filtering face piece respirators;

(B) half mask respirators;

(C) full face mask respirators; and

(D) powered respirators fitted with a fan and filter(s) to supply air

to a half mask, full face mask, visor, hood or helmet, blouse,

half suit or full suit.

II. Breathing equipment provides clean air or oxygen from an independent,

uncontaminated source. The most common types are:

(A) fresh air hose equipment,

(B) constant flow compressed air equipment, and

(C) breathing apparatus which includes full face masks and full

suits supplied either from compressed air lines or self -

contained cylinders of compressed air.


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2. Describe the procedure taken when there is radioactive spillage in

your lab.

The procedure of radioactive spillage is different based on the quantity of the

spillage.

Minor Spillage (less than 0.05 micr ocuries/2kBq)

A minor spill involves the spill of radioactive material in such quantities or under such

circumstances that a significant internal or external radiation hazard is not created,

and which will not produce significant airborne contamination. If a minor spill occurs:

1. Notify all other persons in the room at once.

2. Confine the spillage area

3. Limit the number of person in the area to those needed to deal with the spill.

4. Wear a Personal Protective Equipment including safety goggles, disposable

gloves, shoe covers, and long-sleeve lab coat

5. Take immediate steps to confine the spill. For liquid spills drop absorbent

paper (eg. Kimwipe) on the spill. For dry spills, dampen thoroughly or place

damp absorbent materials over the spill, taking care not to spread the

contamination. Water may generally be used except where chemical reaction

with water would generate an air contaminant. Oil may then be a reasonable

substitute.

6. Dispose of all materials contaminated by the spill and its cleanup in a

radioactive disposal trashcan or clearly label plastic bag.

7. Mark the area of spills and label with the type of radioactivity (eg. C -14,H-3).

8. Delineate and block off the contaminated area to insure that others will not

walk through the area.

9. Do not allow anyone to leave the contaminated area without being monitored.

Make note of the names of all persons involved with the spill.


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Major Spillage (over 1 mCi (37 MBq)

A major spill of radioactive material occurs in such quantities or under such

circumstances that a significant internal or external radiation hazard to personnel,

including those outside the immediate vicinity of the spill, exists, but which does not

produce significant airborne contamination. If a major spill occurs:

1. Notify all persons not involved in the spill to vacate the room at once.

2. If the spill is liquid, and the hands are protected, right the container.

3. If the spill is on the skin, flush thoroughly.

4. If the spill is on clothing, discard outer or protective clothing at once.

5. Do not attempt to clean the spill. Wait for the Radioactive officers to come andclean the space.

6. Vacate and secure the room to prevent re -entry. Keep the area clear of

spectators.

7. Limit the movement of persons involved in the spill to a specified area of

assembly to prevent the spread of contamination. Do not allow anyone to

leave the area of assembly without being monitored. Make note of the names

of all persons involved in the spill.


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Possibility of Airborne Contamination

An airborne release of radioactive material may occur due to evaporation;

vaporization; explosion; combustion; formation of a smoke, dust or spray; gas

escape, etc. If an airborne release occurs:

1. Evacuate all persons from the room or area immediately.

2. Shut all doors to the room or area.

3. Post guards, as needed, to insure that no one re-enters the room or area and

to keep the general area clear of spectators.

4. Assemble all persons who were present in the room or area at the time of the

incident. The place of assembly should be near the conta minated area to

minimize the spread of contamination, but far enough removed to prevent

continued involvement. Do not permit these persons, except in instances of

clear medical emergency, to leave the place of assembly until after the

"Health Physicist" has arrived.

5. If contamination of the skin or clothing is known or suspected, begin personal

decontamination as follows:

6. Remove all contaminated clothing.

7. Wash contaminated areas of skin with mild soap and water.

8. Do not allow anyone to remain in or re -enter the area in which airborne

contamination occurred unless it is certain that the person has adequate

respiratory and personal protection.

.


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3. Explain how a person working in a lab would know how much

exposure he gets from the radiation.

When handling radiation substances, the exposure is essential to prevent

harmful effects on the usage. The common radiation detectors are known as

Dosimeter. Dosimeter provides a measurement on how many radiations is present in

a given time. There are several types of Dosimeter:

A. Quartz fiber dosimeter

B. Film badge dosimeter

C. Thermoluminescent dosimeter (TLD)

D. Solid state (MOSFET or silicon diode) dosimeter

The simplest form of knowing the radiation exposure is by using TLD badges.

TLD badges are used to monitor personnel for exposure of the body to penetrating

ionizing radiation such as gamma and x-rays, and exposure of the skin to less

penetrating radiation such as beta particles. For most individuals results of the TLD

badge readings are also used as estimates for the exposure of the lens of the eye.

TLD badges must be worn by personnel working with most sources of ionizing

radiation. Film badges will be worn at all times when gamma emitters such as Cr -51,

Co-60, Cs-137, I-125, and I-131 are used and by any X-ray machine operators.

When not in use, film badges are to be kept in a cool dry non -exposed area.

Ring dosimetry device are used to monitor for radiation exposure to the hands and

are issued to personnel handling millicurie quantities of 32P or other "hard" beta

emitters, and to personnel handling large gamma -emitting sources. Ring badges

must be worn under gloves with the sensitive portion of the ring toward the source.

The ring dosimeter contains a small radiation -sensitive lithium fluoride crystal. Whenatoms in the crystal are exposed to radiation, electrons are trapped in an excited

state until the crystal is heated to a very high temperature. The released energy of

excitation, which is given off as visible light, is mea sured to determine radiation dose.

This phenomenon is called thermoluminescence and dosimeters that use this

principle are often referred to as TLDs. Both the body and ring badges do not detect


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radiation from beta emitters with energies less than 250 keV. Consequently,

dosimetry is not issued for persons using H-3, C-14, P-33 and S-35. (cited from

Princeton University, Environmental Health & safety).

Some work spaces are issued with a single whole body badge. This whole

body dosimeter should be worn on the collar outside of any protective equipment

worn or lead apron. Readings from this position provide an estimate of the radiation

exposure to the eyes.

Another badge of Dosimeter is Film Badge. It is worn on the outside surface of

lab coat around chest or torso. This location monitors exposure of most vital organs

and represents the bulk of body mass. If protective clothing is worn then the badge is

worn underneath the protection to monitor the dose actually received by the

operator. The advantages of Film Badge are:

A. Permanent record of exposure: The developed film is physical evidence

of the radiation exposure. The film can be stored after developing and

reading, and could be reviewed at a later date if there is a query over

exposure.

B. Exposure pattern discrimination: A film badge offers limited

discrimination between different patterns of exposure. A single exposure

tends to leave sharp shadows on the film from the filters, whereas

multiple small exposures at different angles will leave a rim of blurring

around the filters. This may allow the linking of a dose with a specific

incident and provides a degree of protection against tampering (e.g.

deliberate exposure to a radiation source).

C. Radiation type detection: Use of multiple filters allows separate

measurement of beta and gamma exposure, and estimation of energy

spectra. Additional filters can be added to detect neutron radiation (e.g.

cadmium). The sensitivity of film to low energy (< 20 keV) gamma or x-

radiation can be better than electronic dosimeters.


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References:

1. http://web.princeton.edu/sites/ehs/radsafeguide/rsg_sec_17.htm

2. http://risk.arizona.edu/emergencyprocedures/radiationspill.shtml

3. http://www.wsu.edu/manuals_forms/HTML/SPPM/S90_Radiation_Safety/ S90

.55_Laboratory_Radiation_Safety_Practices.htm

4. http://en.wikipedia.org/wiki/Dosimeter

5. http://en.wikipedia.org/wiki/Film_badge_dosimeter

6. http://web.princeton.edu/sites/ehs/dosimeter/dosimetryinfo.htm#10

7. www.esf.edu/radsaf/m2000.pdf

8. sw.org/web/... /MRBLabProcedureManualforRadioactive Materials2006.pdf

9. www-pub.iaea.org /MTCD/publications/ PDF/PRTM-5_web.pdf

10.www.mun.ca/health_safety/ procedures/S-011_Lab_Safety.pdf

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Describe the Perspective Clothing That Should Be Worn for the Lab Staff Working in a Lab With Radioactive Elements