Adequacy of personal air samplers for monitoring plutonium intakes

When personal air samplers (PAS) are used to estimate plutonium intakes, the number of particles collected is often small, and substantial errors in the estimate can arise from random statistical error. By using a Gaussian approximation for the probability distribution of intake following a single PAS measurement, we have derived simple algebraic expressions for the probability that an estimated intake (or committed dose equivalent), from a series of PAS measurements, will be exceeded by any given factor F. A small computer program written in BASIC is listed in an appendix to aid evaluation. From these expressions, together with a definition of adequacy used by the ICRP, the aerosol conditions under which the PAS will give inadequate estimates of intake are defined. (author)