A Model for Estimating the Inhalation Exposure to Radon-222 and Daughter Products from the Accumulated Lead-210 Body Burden

Abstract

Abstract

Underground uranium miners are exposed to radon-222 and its daughterproducts. It has been difficult to quantitatively determine the exposure to these daughter products since the atmospheric concentration varies in time and space. Lead-210, a residual of these daughter products, is held tenaciously by the body. After examining the data on the retention of stable lead in humans, and the retention of lead-210 in dogs, an eight compartment model was developed to describe this data. This model was applied to a set of 32 miners whose exposure history had been estimated with the result that the body burden of lead-210 was estimated to within an order of magnitude of the experimental results. A computer program was written for the least squares fitting of any retention function to any specified exposure or intake record. This program was used to fit five retention functions to the uranium miner data with the result that the lead-210 body burden could be estimated to within a factor of 2 with 68% confidence and within a factor of 4 with 95% confidence.