Which method is NOT approved for determining depleted uranium exposure?

Depleted uranium exposure can be assessed through specific methodologies that measure the presence of uranium in biological samples. Among the options provided, hair analysis is not an approved or reliable method for determining depleted uranium exposure. This is primarily due to the fact that uranium does not accumulate in hair in a way that correlates reliably with exposure levels.

Bioassays, urine analysis, and fecal testing are well-established methods used in radiation safety and toxicology for evaluating uranium exposure.

Bioassays involve analyzing biological samples like blood or urine to measure amounts of uranium, which allows for understanding internal doses from exposure. Urine analysis, in particular, is the most common approach because uranium is often excreted through the kidneys, making it an effective way to gauge recent exposure. Fecal testing can also be utilized to measure uranium excretion, especially after ingestion, further cementing its role in exposure assessment.

In contrast, hair analysis lacks the scientific backing and methodological rigor needed for such evaluations and therefore is not considered reliable for this purpose.