Cancer risks from radon in indoor air and drinking water in Sweden. The Swedish Radiation Protection Authority's risk assessment

Publisher Summary SSI deems it unlikely that the annual number of cases related to radon in Sweden should exceed 1000. The estimation is based primarily on residential case–control studies, particularly the Swedish national epidemiological radon study presented in 1993 and the recent study of non-smokers. There is a synergistic effect between tobacco smoking and radon that implies that most of the radon-related lung cancer cases, almost 90 percent, occur among smokers. The risk for non-smokers is consequently much smaller than for smokers. Calculations show that up to 150 lung cancer cases per year can be avoided if remedial measures are taken in existing dwellings with radon concentrations exceeding 400 Bqm −3 (the action level for radon in existing dwellings in Sweden). Giving up smoking is the most effective measure an individual can take to reduce the risk of lung cancer from radon. The average effective dose to the Swedish population from consumption of waterborne radon is estimated to about 0.01 mSv per year. At 100 Bq L −1 , the action level for radon in public water supplies in Sweden, the annual effective dose is about 0.02 mSv per year and at 1000 Bq L −1 , the recommended upper level for private wells, the annual dose is about 0.2 mSv per year.