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RADON EXPOSURE AND LUNG CANCER RISK
- CZECH COHORT STUDY ON RESIDENTIAL RADON

L Tomášek 1 , E Kunz 1 , T Müller 1 , J H ù lka 1 , A Heribanová 2 , J Matzner 2 , V Pla è ek 3 , I Burian 3 , and J
Hole è ek 3
1 National Radiation Protection Institute,
Šrobárova 48, 100 00 Prague, Czech Republic 2 State Office for Nuclear Safety,
Senovážné nám. 9, 110 00 Prague, Czech Republic 3 Institute for Emergency Medicine and Expertise,
262 31 P ø íbram-Kamenná, Czech Republic

Epidemiological evidence of lung cancer risk from radon is based mainly on studies of men employed underground in mines where exposures are relatively high in comparison to indoor
exposure. Nevertheless direct evidence of risk from residential radon is desirable. In 1990, a study
was started comprising 12 000 inhabitants of an area with elevated radon concentrations. The mean
level in the houses was higher than general mean of the country by factor of five. In the period
1961-95, a total of 173 lung cancers were observed. Comparing to nationally expected numbers
(E), the observed number (O) of cases is elevated (O/E=1.11) - in contrast to generally low figures
for cancers other than lung (O/E=0.85). Lung cancer risk related to cumulative exposures
experienced in the past 5-24 or 5-35 years was both significant. In relation to standard radon
progeny concentration 100 Bq/m 3 , the excess relative risk coefficient was 0.103 (95% CI: 0.039 –
0.168), the value somewhat lower than findings in other indoor studies.
Running head: Czech cohort study on residential radon and lung cancer

Key words: Residential radon, Lung cancer, Cohort study, Cumulative exposure, Relative risk