Division of Medical Physics and Radiation Safety

617 638 7052

Radiation Safety Awareness

for

This training does not substitute for Basic Radiation Safety Training.

You will

Chemistry Students

Disclosure

This training does not substitute for Basic Radiation Safety Training offered to BU Radioisotope

Authorized Users.

You are only authorized to use radioactive material for during this class-XX.XX.

Massachusetts Department of Public Health Radiation Control Program (RCP) issued Radioisotope License to:

Boston University and Boston Medical Center

(BU) and (BMC) Medical + Research Patient Use X-ray, Therapy Units, and Lasers

Radioactive Materials Licensure

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BROAD SCOPE MATERIALS LICENSE

BUBU

RSC

Permit Holder

User

DMPRS

Radiation Supervisor/Lab Coordinator

Radiation Use at BU and BMC

Radiation is used at BU and BMC as:

Radioactive Materials Radiation Generating

Devices Irradiators

Radiation Protection Office\Dept\12 Training Program Management\Maintenance Training

Radiation Uses at BU and BMC

Examples: Research with radioisotope tracers to study

diabetes, infection, cancer and DNA Medical Use Irradiating patient’s blood to prevent transfusion

reactions Heart Scans Treating Prostate Cancer Diagnostic X-rays (Dental, Chest, CT, etc.)

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ALARA An acronym for "As Low As Reasonably Achievable." It

means making every reasonable effort to maintain exposures to ionizing radiation as far below the dose limits as practical.

The goal of radiation protection is to keep radiation doses As Low As Reasonably Achievable

BU is committed to keeping radiation exposures to all personnel ALARA

The National Council on Radiation Protection and Measurements (NCRP) published a study of the U.S. population’s exposure to radiation in 2009. The chart below shows sources that contributed to an annual average dose of 620 millirem per year. This is a national average, individual exposures will vary.

Sources of Radiation Exposure NCRP Report No. 160 (2009)

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Do you workdirectly with a

source of radiation?

NoBadge

Required

Is the radiationsource an

isotope or a machine?

No

Yes

Do you work with at least one of the followingisotopes (greater than activity indicated)?(badge type in ( ).

Brachytherapy Sources (1,4) >1 mCi/qtr. of gamma or positron emitter (1,4) >1 mCi high (>500 keV) max energy Beta emitter (1,4) Nuclear Radiology Isotopes (1,4)

Do you work with any one of the following machines?(badge type in ( )

Fluoroscope (2,3) LINAC (1) Diagnostic x-ray (2,3) CT (2,3)

Isotope Machine

A badge is mandatory

A badge is voluntary

Yes

NoBadge Type1 – Whole body2 – Collar3 – Waist4 - Ring

Dosimetry Requirement Decision Tree

No

Radioactive Stock Material

Radiation is Energy

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Basic Terms

Radiation: energy in transit in the form of high speed particles and electromagnetic waves.

Radioactivity: Characteristic of an unstable atom that releases energy in the form of a particle or electromagnetic wave.

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Types of Ionizing Radiation

Alpha particles: contains 2 neutrons and 2 protons, which is ejected from the nucleus of a radioactive atom.

Beta particles: A high-speed electron or positron, usually emitted by an atomic nucleus undergoing radioactive decay. Electrons carry a negative charge.

X-rays: Electromagnetic radiation originating in the electron field of an atom.

Gamma rays: A gamma ray is an electromagnetic radiation originating in the nucleus of an atom.

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Types of Radiation

Ionizing Radiation: Radiation capable of liberating electrons from an atom. ex. beta particles, x-rays

Non-ionizing radiation: Radiation not capable of liberating electrons, but can excite the atom.

ex. microwaves, radio waves, lasers

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Terms and Definitions

Radiation: Energy in transit in the form of high speed particles and electromagnetic waves.

Radioactivity: Characteristic of an unstable atom that releases energy in the form of a particle or electromagnetic wave.

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Units

There are two systems of units used in the measurement of radioactivity and radiation dose.

The older units (Curie,Rad and Rem) - the American System and U.S. regulatory units.

The widely-used international units (Becquerel, Gray and Sievert) – International System or “SI” system.

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Radiation Quantities

Curie: 3.7x1010 disintegrations per second or 2.2x1012 disintegrations per minute.

1 curie (Ci) = 2.2 x 1012 dpm 1 millicurie (mCi) = 2.2 x 109 dpm 1 microcurie (µCi ) = 2.2 x 106 dpm

Example: 100 µCi = 0.1 mCi = 2.2 x 108 dpm

Becquerel: One disintegration per second. (SI system) 1 mCi = 37 Megabecquerels (MBq) 1 µCi = 37 kilobecquerel (kBq)

Example: 0.1 mCi = 3.7 MBq = 100 µCi

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Radiation Units

Roentgen: unit for measuring the amount of ionization in air (exposure) due to gamma or x-rays.

RAD: Radiation Absorbed Dose.Unit used to describe the amount of energy absorbed from radiation in any type of medium.

100 rads = 1 Gray (SI)

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Radiation Units

REM: Unit used for measuring human dose equivalent. 100 rem = 1 Sievert (SI) 1 rad of alpha = 20 rem 1 rad of beta = 1 rem

Note: Two different types of radiation may deliver the same absorbed dose, but produce a different biological affect, and hence, dose equivalent.

1 rad of alpha = 20 rem 1 rad of beta = 1 rem

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Half-Life

The time required for any given radioisotope to decrease to one-half of its original activity by radioactive decay.

This period of time is called the half-life.P32 - 14.3 days

C14 - 5730 years

H3 - 12.3 years

S35 - 89.7 day

I125 - 60 days

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External Exposure

Common isotopes with external exposure potential

ex: P-32, I-125, Cr-51

Not all radioisotopes are external exposure hazards

ex: H-3, C-14, S-35

External Radiation

Three ways to reduce exposure from external radiation sources

Time

Distance

Shielding

30 min work time in a 40 mR/hr field= ???

.5 hr x 40 mR/hr = 20 mR

Time and exposure have a linear relationship. As time decreases, the exposure decreases proportional to time.

50 cm 100 cm 200 cmDistance from

source:

Dose rate: 40 mR/hr 10 mR/hr 2.5 mR/hr

Distance and exposure have an inversely proportional relationship. As distance increases, photon exposure decreases at the rate of the inverse of distance squared.

99mTc dose in shielded Pb carrying case

The type of shielding that is suitable for one type of radiation may not be suitable in shielding another. Always consult the Radiation Safety Office to ensure that your shielding is appropriate.

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How To Minimize External Exposure

DISTANCE : Inverse Square Law 10 mR/hr @ 1 ft At 2 ft. - What is your exposure?

10 mR/hr = 2.5 mR/hr 2 ft.2

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Shielding

Alpha particles can be stopped by a sheet of paper.

Most Beta particles can be stopped by 1-2 cm of Plexiglas.

Most gamma and x-ray photons can be absorbed by several cm of lead.

Neutrons may require several feet of concrete.

RADIOACTIVE MATERIAL

CAUTION

Radioactive material used or stored

Radioactive Labeling

CAUTION

Radiation Label

Refers to areas accessible to personnel, in which a major portion of the body could receive a dose of 5 mrem in anyone hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.

RADIATION AREA

Do NOT enter unless authorized

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Contamination

Definition: Radioactive material where it shouldn’t be.

e.g. floors, bench tops, hands

All radioisotopes have contamination potential even if they do not have external exposure potential.

The goal is to prevent contamination from getting on to your skin and/or inside your body.

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Skin Contamination

Cool water, mild soap

2-3 minutes working up a good lather, dry

No harsh chemicals or detergents

Survey for contamination

Notify the RPO 617-638-7052

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SPILLS

S Stop all work and contain spill W Warn others I Isolate Area M Minimize exposure and monitor N Notify RSO

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Proper Survey Technique

Use appropriate survey meter Check battery Audible on Check background level

Audio On/Off Switch

Rotary Switch Off Battery Check Scalar Multiplier

Battery Compartment

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Surveys

Geiger Counters used for all isotopes (EXCEPT H-3)

Note: Contamination Surveys use for I-125 use Gamma Scintillator Gamma Scintillator (NaINaI) probe.

End Window PancakePortable

Survey Meter

Gamma Scintillator (NaI) probe

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Survey Meter Face Plate

Top scale : 0 - 4.2 Kcpm on X 1X 1 multiplier

Bottom scale: 0 – 200 mR/hr on X 100X 100 multiplier only

Middle scale: 0 – 2.0 mR/hr on X 1X 1 multiplier

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Wipe Tests A wipe test only assesses removable contamination. A dry material to wipe an (100 cm2) area of potential

radioactive contamination. For H-3, a wipe test is the only means to assess

potential contamination. For P-32, S-35, C-14, use Geiger Mueller Probe for

fixed and removable contamination surveys

Liquid Scintillation

Counter

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Container Labeling

You must ensure that all containers possessing radioactive material are labeled with: Radioisotope Quantity Date Chemical Name

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Sulfur 35- Amino Acid Precautions

Because of volatility: Use fresh stocks Open Stock vial in hood Place charcoal in incubators, water baths,

etc. Monitor with GM (pancake) especially

centrifuges, incubators, bag sealers

Working with Eppendorf tubesWorking with Eppendorf tubes

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Use flat top tube opener to reduce radiation levels to fingers

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Radioactive Waste Categories

Solid waste Aqueous liquid waste Organic liquid Deregulated liquid scintillation vials Regulated liquid scintillation vials Animal carcass/tissue Volatile material Stock vials

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Rad. Waste Guidelines

Put radioactive needles etc., in “radioactive” sharp container

No liquids No lead pig or radiation labels in rad.

waste (deface all radiation labels) Assure rad. waste container labeled to

prevent housekeeper from emptying trash

Call DMPRS for any questions at

617-638-7052

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Radiation Safety Records

All records must filled out and up to date!

Inventory Surveys Waste logs Sink logs

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Radiation Safety Checklist

All persons completed required training? Are radioactive materials secured? Do you use a survey meter and/or wipes to

assess exposure and/or contamination? No eating, drinking or application of

cosmetics in the laboratory? Report spills to Radiation Safety 617 638

7052?

Security

Security involving research material

All radioactive material must be secure from unauthorized removal or access.

The Authorized User of radioactive material must maintain constant surveillance, and use devices or administrative procedures to prevent use by unauthorized personnel.

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Security of Radioactive Material

You can do one or more of the following: Keep radioactive material in constant view Lock up radioactive stock solutions Lock the laboratory Always keep the access door to your floor of

the building locked. ( Use Key Card Access or the Combination Lock )

Risk of exposure to ionizing radiation Minimal Exposure = Minimal Risk

If 100,000 persons were exposed to 10 Rem of radiation each, 800 excess cancer deaths would be expected during their remaining lifetimes in addition to the nearly 20,000 cancer deaths that would occur in the absence of radiation.-BEIR V Report, page 162 - 1989

Latest Biological Effects Studies

THE END

Please complete the Radiation Quiz to fulfill your training requirements

If you have any questions, please contact the RPO at 617-638-7052