Estimation of radon exposure history for analysis of a residential epidemiological study

Traditional methods for assessing radon exposure in epidemiological studies have used current ambient detector measurements as surrogates for concentrations decades ago in past residences occupied by study subjects. Substantial temporal and spatial variability has been found which challenges the validity of this practice. As an alternative, CR-39 surface monitors were attached to selected glass objects to measure alpha emissions from radon progeny and infer past exposures of subjects. The validity of the use of surface monitors to detect alpha emissions in glass was successfully demonstrated by comparing results of these monitors with pulse ionisation chamber measurements. Subsequently, surface monitor and ambient detector results were compared, and factors such as household smoking and use of windows for measurement were examined. Individually, both the surface monitor and the ambient detector methodologies each gave highly repeatable results (Pearson product-moment correlations of 0.81 and 0.97, respectively), but the consistency between the two technologies was only satisfactory (correlation of 0.53).