Doses to systemic tissues from radon gas

A dynamic model for the retention of inert gases in the body has been developed for the calculation of inhalation and ingestion dose coefficients. Based on blood flow, the model formulates first order transfers between compartments and is consistent with the models of ICRP. Annual effective dose for inhalation of radon gas is estimated to be 28 μSv for continuous exposure to the UK indoor average radon in air concentration (20 Bq.m-3, with the largest contribution made by lung. For ingestion, the dose coefficient is estimated to be 10-8 Sv.Bq-1, of which 97% is contributed by dose to stomach wall. It is predicted that dose coefficients for children are similar to those for adults. (author)