Health Physics Questions and Answers - Question 435

Question 435: The rule requires that "the assigned deep-dose equivalent... must be for the part of the body receiving the highest exposure. [The dose] may be assessed from surveys or other radiation measurements for the purpose of demonstrating compliance with the occupational dose limits, if the individual monitoring device was not in the region of highest potential exposure." In the event of a hot particle exposure to a portion of the whole body, it is unlikely that the associated deep dose equivalent (DDE) resulting from the hot particle gamma radiation would be appropriately measured by an individual monitoring device due to the localized nature of the exposure. Is it required that the DDE associated with a hot particle exposure be assessed and added to the monitored DDE for the purpose of demonstrating compliance with the occupational dose limits?

Answer: Yes. Although, for a hot particle on the skin, the deep dose equivalent is generally a small fraction of the shallow dose equivalent, it does need to be assessed.

(Reference: 10 CFR 20.1201)