Residential Radon and Lung Cancer Risk: An Updated Meta-analysis of Case-control Studies

Abstract

Background: Numbers of epidemiological studies assessing residential radon exposure and risk of lung cancer have yielded inconsistent results. Methods: We therefore performed a meta-analysis of relevant published casecontrol studies searched in the PubMed database through July 2011 to examine the association. The combined odds ratio (OR) were calculated using fixed-or random-effects models. Subgroup and dose-response analyses were also performed. Results: We identified 22 case-control studies of residential radon and lung cancer risk involving 13,380 cases and 21,102 controls. The combined OR of lung cancer for the highest with the lowest exposure was 1.29 (95% CI 1.10-1.51). Dose-response analysis showed that every 100 Bq/m 3 increment in residential radon exposure was associated with a significant 7% increase in lung cancer risk. Subgroup analysis displayed a more pronounced association in the studies conducted in Europe. Studies restricted to female or non-smokers demonstrated weakened associations between exposure and lung cancer. Conclusions: This metaanalysis provides new evidence supporting the conclusion that residential exposure to radon can significantly increase the risk of lung cancer in a dose-response manner.

Response to Fornalski et al.

“…' We respectfully disagree. While our paper is not an original epidemiological study on the association between lung cancer and low-level radon in Swedish dwellings, such studies have been performed [1] and show results completely compatible with the results of previous multicenter studies or meta-analyses in Europe and the USA [2][3][4] and large studies from China [5]. In our study we used the exposure-response (ER) function found by Darby et al [2], since the European results were considered most representative of the Swedish situation.…”

A Comparison of Two Methods for Ecologic Classification of Radon Exposure in British Columbia: Residential Observations and the Radon Potential Map of Canada

“…Exposure to radon gas is the second-leading cause of lung cancer (behind tobacco), and the leading cause in non-smokers. 1 Several case-control studies report an 8-12% increase in lifetime risk of lung cancer associated with each 100 Becquerel per cubic metre (Bq/m 3 ) increase in long-term exposure to radon, [2][3][4] and no evidence of a threshold or "safe" level of exposure. 2 Smoking and radon also interact synergistically, causing a greater increase in lung cancer risk for smokers than for nonsmokers.…”

“…Similar studies from other countries have reported similar results, therefore much of the evidence for residential radon policy in Canada and worldwide has been derived from meta-analyses that increase statistical power by combining data from multiple case-control studies. [2][3][4] Ecologic designs provide another way to increase the size of study populations. To date there have been no ecologic studies on radon exposure in Canada, but those conducted elsewhere report associations between radon and multiple cancers.…”

Construction of new houses on a uranium vein outcrop: a case study from the Czech Republic

“…Residential radon exposure is considered a risk factor for lung cancer ( [1,2] and others) but there is a lot of controversy on this topic; some authors suggest that it is only an assumption [3,4]. On the other hand, a short-term radon exposure can be healthy from the balneological point of view, as we know from many spas around the world [5,6].…”