Occupational Exposure Protection of the Worker

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Lab 6

• Occupational ExposureProtection of the Worker

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Protection of the worker
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• The use of radiations and radiolabeled products
  for any purpose is governed by regulatory
  agencies in different countries all over the
  world.
• The use of radiopharmaceuticals in humans was
  almost unregulated until the late 1950s.
• Until 1963, all reactor-derived
  radiopharmaceuticals were under the control of
  the Atomic Energy Commission
• (AEC, now the Nuclear Regulatory Commission,
  (NRC)) only for their radiation hazards.
• The therapeutic or diagnostic efficacy and the
  pharmaceutical quality of radiopharmaceuticals
  were not regulated by the AEC or by the U.S. Food
  and Drug Administration (FDA) until the early
  1960s.
• In 1963 the FDA introduced rules stating that the
  clinical efficacy of all radiopharmaceuticals.

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Radiation Protection

• Because radiation can cause damage in living
  systems, international and national organizations
  have been established to set guidelines for the
  safe handling of radioactive materials.
• The International Committee on Radio logical
  Protection (ICRP)
• The National Council on Radiation Protection and
  Measurement (NCRP)
• They set guidelines for all radiation workers to
  follow in handling radiations

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Occupational Exposure Protection of the Worker
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RESPONSIBILITIES

• Licensees shall ensure for all workers that
• Occupational exposure be limited and optimized
• Suitable and adequate facilities, equipment and
  services for protection be provided
• Appropriate protective devices and monitoring
  equipment
• be provided and properly used
• Appropriate training be provided as well as
  periodic
• retraining and updating

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RESPONSIBILITIES

• Workers shall
• Follow any applicable rules for protection
• Use properly the monitoring devices and the
  protective equipment and clothing provided

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Caution Signs and Labels

• The NRC requires that specific signs, symbols,
  and labels be used to warn people of possible
  danger from the presence of radiations
• These signs use purple, and black colors on a
  yellow background
• Some typical signs are shown in the figures

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• Caution Radiation Area This sign must be posted
  in radiation areas.
• Caution High Radiation Area or Danger High
  Radiation Area This sign must be posted in high
  radiation areas.
• Caution Radioactive Material or Danger
  Radioactive Material This sign is posted in
  areas or rooms in which 10 times the quantity or
  more of any licensed material specified in
  Appendix C of 10CFR20 are used or stored.
• All containers with quantities of licensed
  materials exceeding those specified in Appendix C
  of 10CFR20 should be labeled with this sign.

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Occupational Exposure Protection of the Worker

• Sources of exposure

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EXPOSURES IN NUCLEAR MEDICINE
Internal Ingested and/or inhaled radionuclides E
xternal Vials, syringes, patients.
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Exposure of the workerExternal Exposure

• Unpacking radioactive material
• Activity measurements
• Storage of sources
• Internal transports of sources
• Preparation of radiopharmaceuticals
• Administration
• Examination of the patient
• Care of the radioactive patient
• Handling of radioactive waste
• Accidents

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Contamination of the worker

• spills
• improper administration
• experimental work with animals
• emergency surgery of a therapy patient

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Dose to worker
2,5
2
1,5
Dose (uSv)
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0,5
0
Dispensing
Injection
Examination
Measurements of this kind can show different
results in different hospitals
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Occupational Exposure Protection of the Worker

• Personal protective equipment. Safe handling of
  sources.

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Principles of Radiation Protection

• Of the various types of radiation the alpha
  particle is most damaging due to its great charge
  and mass followed by the b particle and the g rays

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Radiation Protection Measures

• Depend on
• Time
• Distance
• Shielding
• Type of radionuclide and its chemical properties

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Time
Dose is proportional to the time exposed
it is wise to spend no more time than necessary
near radiation sources
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Consequence

• Reduce time in contact with radiation sources as
  much as compatible with the task
• Training of a particular task using
  non-radioactive dummy sources helps

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Distance

• It is recommended that an individual remains as
  far away as possible from the radiation source.
• Procedures and radiation areas should be designed
  such that only minimum exposure takes place to
  individuals doing the procedures or staying in or
  near the radiation areas.

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Patient with iodine-131
0.5 0.1 0.06 0.03
1000 MBq I-131
0 0.5 1 2
m
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Consequence

• Distance is very efficient for radiation
  protection as the dose falls off in square
• Examples
• long tweezers for handling of sources
• big rooms for imaging equipment

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Shielding

• Various high atomic number (Z) materials that
  absorb radiations can be used to provide
  radiation protection
• The ranges of alpha and b particles are short in
  matter the containers themselves act as shields
  for these radiations
• Alpha can be stopped by a piece of paper
• Beta low molecular weight element Al or glass can
  stop its effect. (Whay dont we use lead for
  shielding of beta radiation?)
• Gama radiations are highly penetrating absorbing
  material must be used for shielding of g-emitting
  sources
• Lead is most commonly used for this purpose.

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Shielding
Barrier thickness
incident radiation
transmitted radiation
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Shielding
Bench top shield Vial shields Syringe shields
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SHIELDING OF SOURCES

• Factors affecting the design
• radionuclide
• activity
• shielding material

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• Devices to measure personnel radiation exposure.
• The film badge is most popular and cost-effective
  for personnel monitoring and gives reasonably
  accurate readings of exposures from b, g, and x
  radiations.
• A Pocket dosimeter. B Film badge holder.
• C Film badge. D Thermoluminescent chip in
  finger badge

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Dos and Donts in Radiation Protection Practice

• Do post radiation signs in radiation areas.
• Do wear laboratory coats and gloves when working
  with radioactive
• materials.
• Do work in a ventilated fumehood when working
  with radioactive gases.
• Do cover the trays and workbench with absorbent
  paper.
• Do store and transport radioactive material in
  lead containers.
• Do wear a film badge while working in the
  radiation laboratory.
• Do identify all radionuclides and dates of assay
  on the containers.

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Dos and Donts in Radiation Protection Practice

• Do survey work areas for any contamination as
  frequently as possible.
• Do clean up spills promptly, and survey the area
  after cleaning.
• Do not eat, drink, or smoke in the radiation
  laboratory.
• Do not pipette any radioactive material by mouth.
• Do monitor hands and feet after the days work.
• Do notify the RSO in case of any major spill or
  other emergencies related to radiation.

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Well, ask a question and feel stupid for 5
minutes or don't ask and be stupid forever.