Which sample types are analyzed in bioassays to determine internal contamination?

• A. Urine or fecal material
• B. Blood samples only
• C. Blood pressure
• D. Saliva

Answer: (A)

Assessing internal contamination relies on analyzing biological samples that reflect what the body has taken up and excreted. The primary sample types are urine and feces because many radionuclides are eliminated from the body through these routes, and measuring what’s excreted helps estimate how much radionuclide the body has accumulated. Urine is most commonly used due to easy collection and its ability to indicate recent intake, while fecal analysis is useful for forms that aren’t readily excreted in urine. In some specific cases, blood samples may be used for particular radionuclides or short-lived substances, but for routine internal contamination assessment, urine and feces are the standard. Saliva isn’t a standard bioassay sample for this purpose, and a blood pressure reading doesn’t provide information about radionuclide contamination.