Problems in radon measurements in context of epidemiological studies

Abstract

Epidemiological case control study is considered to be primary instrument to investigate the relationship between population indoor radon exposure and risk of lung cancer. A number of such studies had been completed in last 15 years and others are running now. Considering indoor radon and progeny some specific efforts should be undertaken to assess the exposure. While the lungs exposure after inhalation arises mainly due to radon progeny, in the case of the radon gas measurements application the researchers have to address the disequilibrium between radon and radon progeny. It is widely accepted by researchers and approved by ICRP that worldwide average value of equilibrium factor is 0.4 though real equilibrium factor value can deviate significantly from average. Temporal variation of indoor radon concentration complicates the evaluation of exposure as well. Three types of variation can be emphasized: diurnal, seasonal and long time. Experimental and modeling investigation of radon entry shown that pattern of indoor radon temporal variation firmly depends on relationship between entry rates of primary radon sources (diffusive and advective) and influencing factors are construction characteristics, climatic condition and life style. To find appropriate parameters describing radon disequilibrium and temporal variation it is necessary to perform special investigation in the representative sample of houses.