Radon Exposure and the Risk of Leukemia

Abstract

Since the 1990's, several authors estimated that radon inhalation may deliver a small amount of irradiation to the red bone marrow, and consequently may increase the risk of leukemia in humans. The objective of this review is to conduct a critical analysis of epidemiologic results currently available concerning the relationship between radon exposure and the risk of leukemia. Nineteen ecological studies, six miner cohort studies, and eight case-control studies published between 1987 and 2000 are included in this review. The limitations associated with each of these studies are discussed. The results of the ecological studies are relatively concordant and suggest an association between radon concentrations and the risk of leukemia at a geographic level. But these ecological studies present important limitations, and some are only crude analyses. Moreover, the results of the cohort and case-control studies, based on individual data, do not show any significant association between radon exposure and leukemia risk. Our conclusion is that the overall epidemiologic results currently available do not provide evidence for an association between radon exposure and leukemia.

Domestic Radon Exposure and Risk of Childhood Cancer: A Prospective Census-Based Cohort Study

“…Previous case–control studies have reported participation < 55%, and exposure measurements were often limited to subsets of study participants (Cartwright et al 2002; Kaletsch et al 1999; Lubin et al 1998; Maged et al 2000; Steinbuch et al 1999; Stjernfeldt et al 1987). In contrast with ecological studies, we had information on a number of potential individual-level confounders (Laurier et al 2001; Tong et al 2012), although adjusting for these variables did not materially affect hazard ratios, suggesting little or no confounding by these factors although we cannot completely exclude residual confounding due to misclassification in the confounder variables. This is consistent with the current knowledge on childhood cancer etiology: There is evidence of increased risks among children with a genetic predisposition and among those exposed to high doses of ionizing radiation (e.g., applied for cancer treatment), but little evidence of environmental risk factors (Belson et al 2007; Eden 2010; McKinney 2005; Pollack and Jakacki 2011).…”

“…However, because these were population-level analyses, control for individual-level confounders was not possible. Results of case–control studies have been inconsistent (Laurier et al 2001; Tong et al 2012), with some studies reporting an association (Maged et al 2000; Raaschou-Nielsen et al 2008) and others not (Cartwright et al 2002; Kaletsch et al 1999; Kendall et al 2013; Lubin et al 1998; Steinbuch et al 1999; Stjernfeldt et al 1987). A recent analysis of a Danish case–control study reported evidence that air pollution from road traffic might enhance the association between radon and childhood leukemia (Bräuner et al 2012).…”

Residential Exposure to Natural Background Radiation and Risk of Childhood Acute Leukemia in France, 1990–2009

“…As stated in several reviews (Laurier et al 2001; Raaschou-Nielsen 2008; Tong et al 2012), most of the studies found positive correlations with radon, whereas no evidence was found for gamma radiation exposure. Population-based case–control studies that included interviews and in-home measurements have reported mixed results, mostly nonsignificant (Raaschou-Nielsen 2008), but their interpretation is hindered by the generally limited participation rates and the subsequent potential for selection bias.…”

Human exposure to high natural background radiation: what can it teach us about radiation risks?

“…Nevertheless, at present, no effect other than lung cancer can be ascribed to radon exposure [50]. For leukaemia, numerous studies have been performed, but a positive association suggested by ecological studies has not been confirmed by studies based on individual data [60, 61]. …”