210Po IMPLANTED IN GLASS SURFACES BY LONG TERM EXPOSURE TO INDOOR RADON

Abstract

Recent epidemiologic investigations of the relationship between residential radon gas exposure and lung cancer relied on contemporary radon gas measurements to estimate past radon gas exposures. Significant uncertainties in these exposure estimates can arise from year-to-year variation of indoor radon concentrations and subject mobility. Surface implanted 210Po has shown potential for improving retrospective radon gas exposure estimates. However, in previous studies, the ability of implanted 210Po activity to reconstruct cumulative radon gas exposure was not tested because glass was not available from homes with known radon-gas concentration histories. In this study, we tested the validity of the retrospective radon gas reconstruction using implanted 210Po surface activity by measuring glass surfaces from homes whose annual-average radon gas concentrations had been measured almost every year during two decades. Regression analysis showed a higher correlation between measured surface activity and cumulative radon gas exposure in these homes (R2>0.8) than was observed in homes where only contemporary radon gas measurements were available. The regression slope (0.57 ky m(-1)) was consistent with our earlier retrospective results. Surface activity measurements were as reliable for retrospective radon gas exposure reconstruction as yearlong gas measurements. Both methods produced estimates that were within 25% of the long-term average radon gas concentrations in a home. Surface measurements can be used for home screening tests because they can provide rapid, reliable estimates of past radon gas concentrations. Implanted 210Po measurements are also useful in retrospective epidemiologic studies that include participants who may have been exposed to highly variable radon concentrations in previously occupied or structurally modified homes.

Estimation of radon exposures to workers at the Fernald Feed Materials Production Center 1952–1988

“…We sought a way of validating our exposure estimates, particularly before 1979. Several case-control studies of radonrelated lung cancer from exposures received in homes (Field, 2001;Steck et al, 2002) employed a method for estimating cumulative exposure. This method involved the use of CR-39 plastic film applied to glass in mirrors or framed pictures that were kept in each home that a case or control inhabited over their adult lifetime.…”

Lung cancer risk due to radon in dwellings—evaluation of the epidemiological knowledge

“…A reduction of measurement error can also possibly be achieved by analysing glass objects in the household via surface monitors [28,29]. Here an even higher EOR was found [4].…”

Radon, secondhand smoke, glutathione‐S‐transferase M1 and lung cancer among women

“…Annual time‐weighted averages were calculated as the sum of the mean radon concentration of all the homes weighted by the years of residence spent in each home using the air‐based α‐track detector measurements. In addition to these air‐based measurements, Missouri‐II derived radon concentrations using the glass‐based dosimeters 26, 27. This method measures decay of polonium‐210, a decay product of radon that can embed in glass objects.…”