Bioassay Requirements
Thyroid Bioassay
Thyroid bioassay are used to assess the intake of radionuclide compounds that tend to concentrate in the thyroid gland (e.g., radioiodine).
Typically, a baseline thyroid bioassay is required prior to handling or observing work with volatile radioiodines for the first time. A second bioassay is required after this first use to ascertain the effectiveness of handling and existing engineering controls. Depending on the activity and frequency of use, an individual user may be required to undergo thyroid bioassay on a regular basis.
Thyroid bioassay may also be requested by the DRS after radioiodine spills, personnel contamination, or other abnormal events.
Urine Bioassay
A urine bioassay is used to assess the intake of radionuclides that do not exhibit gamma ray emissions and are usually only detectable by liquid scintillation counting. Many radionuclides and radioactive compounds are removed from the blood via the kidneys and can be measured in the urine for a period of time following the intake.
A baseline urine bioassay may be required prior to participation in many radiation safety protocol activities based on the nature of the material or its quantity. If a urine bioassay is required, an initial baseline prior to radionuclide use will be requested. A second bioassay is required after this first use to ascertain the effectiveness of handling and existing engineering controls. Depending on the activity and frequency of use, an individual user may be required to undergo urine bioassay on a regular basis.
A urine bioassay may also be requested by the DRS after radioactive spills, personnel contamination, or other abnormal occurrences.
Air Sample Requirements
Personnel Air Monitoring
Along with bioassays, personnel air monitoring may be required when using certain volatile radionuclides.
A personnel breathing-zone air monitoring apparatus is typically installed by the DRS. The research staff must collect and submit the air samples following each experiment involving volatile radionuclides. Documentation about the research experiment (nuclide and activity handled, air flow rate, and length of procedure) must accompany the air sample.
Based on air monitoring results, the DRS may request a bioassay if an uptake is suspected.
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