Correlation of lung dose with Rn concentration, potential alpha-energy concentration and daughter surface deposition: a Monte Carlo analysis.

In the evaluation of lung cancer risk from Rn daughters in the home environment, measurements of Rn concentration or potential alpha-energy concentration (PAEC) have served as proxies for actual radiation dose to the lungs. This paper uses a single-compartment room model, model parameters from a number of recent studies, and Monte Carlo analysis to explore the relative value of Rn concentration, PAEC, and room surface deposition, or plate-out, as estimators of lung dose. Results indicate that Rn concentration and PAEC are fairly good estimators, explaining roughly 50-70% of the variation in dose for the conditions studied, over the range of Rn concentrations considered (74-555 Bq m 3). The relative advantage of one measure over the other depends upon the variability in a number of factors across the houses being evaluated. Room surface activity deposition was not found to be superior to the traditional measures of Rn concentration and PAEC. Significant room for improvement remains in the development of simple home monitors providing an improved estimation of lung dose.