DOMESTIC RADON EXPOSURE AND CHILDHOOD LEUKAEMIA AND LYMPHOMA: A POPULATION-BASED STUDY IN CANADA.

In this paper, we revisit the possibility, first raised using a data set collected in the 1970s, that there is a link between average radon concentrations and the incidence of childhood leukaemia and lymphoma in Canada. Following the launch of the National Radon Program in 2007, Health Canada completed a long-term radon survey in 33 census metropolitan areas (CMAs), which covers about 70% of the Canadian population. We used this data, together with leukaemia and lymphoma incidence rates among children (0-14 years of age) in the past decade (2006-15), and tried to link the city-level average radon concentrations to the leukaemia and lymphoma incidence rates in 33 major Canadian cities. Analyses were conducted for six subtypes (ALL, AML, CMD, HL, NHL and BL) of leukaemia and lymphoma. Estimated doses to red bone marrow from domestic radon exposure were low and we did not find any association between radon exposure at home and the increased risk for developing leukaemia among children under 15 years of age living in the CMAs. The results indicate a slight positive association for AML among 1-4 year males in CMAs of Peer Group C and NHL among 5-9 year females in CMAs of Peer Group A; however, these should be interpreted with caution owing to the crude exposure assessment and possibilities of other confounding factors.