Indoor occupancy and radon exposure in Finland

Abstract

Publisher Summary Radon is the second largest cause of lung cancer after smoking in most countries. Epidemiological studies in residential environments seem to confirm the connection between radon and lung cancer that was found in studies on miners. However, the risk ratios of residential studies have broad confidence intervals and they often lack statistical significance. One reason for this is random error in the exposure assessment. This kind of error may even attenuate estimate of risk ratio. To assess radon exposure, the radon concentration in the environment where the participants in the study live and the proportion of time they spend there (occupancy factor) have to be determined. Individuals spend varying times in various human living environments that have different radon concentrations. Generally, dwellings have the highest average radon concentration. The radon concentration in workplaces and in public buildings is, on average, lower than in dwellings, and it is at its lowest outdoors and in vehicles. In addition, the radon concentration in buildings varies according to the time of day and season, typically being higher at night and in winter.