Glass-based radon-exposure assessment and lung cancer risk

Abstract

Lung cancer risk estimation in relation to residential radon exposure remains uncertain, partly as a result of imprecision in air -based retrospective radonexposure assessment in epidemiological studies. A recently developed methodology provides estimates for past radon concentrations and involves measurement of the surface activity of a glass object that has been in a subject's dwellings through the period for exposure assessment. Such glass measurements were performed for 110 lung cancer subjects, diagnosed 1985 to 1995, and for 231 control subjects, recruited in a case -control study of residential radon and lung cancer among never -smokers in Sweden. The relative risks ( with 95% confidence intervals ) of lung cancer in relation to categories of surface -based average domestic radon concentration during three decades, delimited by cutpoints at 50, 80, and 140 Bq m À 3 , were 1.60 ( 0.8 to 3.4 ), 1.96 ( 0.9 to 4.2 ), and 2.20 ( 0.9 to 5.6 ), respectively, with average radon concentrations below 50 Bq m À 3 used as reference category, and with adjustment for other risk factors. These relative risks, and the excess relative risk ( ERR ) of 75% ( À 4% to 430% ) per 100 Bq m À 3 obtained when using a continuous variable for surface -based average radon concentration estimates, were about twice the size of the corresponding relative risks obtained among these subjects when using air -based average radon concentration estimates. This suggests that surface -based estimates may provide a more relevant exposure proxy than air -based estimates for relating past radon exposure to lung cancer risk.

Two dimensions of measurement error: Classical and Berkson error in residential radon exposure assessment

“…A detailed revalidation is of immediate interest in the light of the on-going implementation of a new assessment procedure of residential radon exposure by measuring polonium in glass objects (e.g. Lagarde et al, 2002).…”

Radon retrospective measurements

“…Some authors have found a stronger positive correlation between implanted 210 Po and lung cancer, than for radon gas based measurements [17,18]. These findings support that radon gas exposure may not be the optimum quantity in the search for radon induced lung cancers in dwellings.…”

“…Some of these track-etch retro devices may also, besides implanted 210 Po, register the local plate out rate of short-lived progenies onto the glass sheet analysed [13,14]. The advancement of these cost-effective in-situ retro devices has made it possible to practice the glass-polonium technique in large-scale radon epidemiological investigations in homes [13,[15][16][17].…”

“…By defining criteria for which type of glass samples to accept, analysing several samples per person, correcting for local plate out variations, etc., the influence from non-dose related variations can be minimized. Lagarde [17], for instance, analysed two glass samples for each individual and used only samples with exposure periods in excess of 15 years. Steck [13] found a correlation of r 2 =0.5 between total radon exposure estimated from contemporary radon gas measurements and the historical average reconstructed from implanted 210 Pb surface activity.…”

Exerpts from the history of alpha recoils

“…The paper in Nature caused a boom in radon retrospective interest and a RARE (Retrospective Assessment of Radon Exposure) research group was funded by the European Union (EU), developing and scrutinizing radon retrospective options. The development of in-situ track-etch techniques for measuring 210 Po implanted into surfaces was the key to large-scale radon epidemiological studies Lagarde et al, 2002;Samuelsson et al, 2001;Steck and Field, 1999).…”