Alpha-particle dosimetry for the basal layer of the skin and the radon progeny 218-Po and 214-Po

The population average dose to the basal layer of the skin is evaluated, in terms of dose per alpha-particle decay per unit area, for radon progeny 218-Po and 214-Po attached to the skin surface. Account is taken of the variation in basal layer depth between different individuals, and results are presented for several anatomical regions. On the face, for example, the population average dose to the basal layer from 218-Po is of the order of 0.5 mu Sv/decay/cm(2) while that from 214-Po is of the order of 1 mu Sv/decay/cm(2). Radiation induced stochastic effects in the skin are generally assumed to originate from target cells located in the basal layer. Provided this assumption is correct, these results suggest that both 218-Po and 214-Po could be regarded as potential carcinogenic agents for the induction of skin cancer.