Exposure to Natural Background Radiation and Association with Childhood Leukemia Incidence in France 1990-2009

Exposure to Natural Background Radiation and Association with Childhood Leukemia Incidence in France 1990-2009Abstract Number:2514 Claire Demoury*, Denis Hémon, Géraldine Ielsch, Christophe Debayle, Olivier Laurent, Jérôme Guillevic, Dominique Laurier, and Jacqueline Clavel Claire Demoury* French Institute for Medical Research and Public Health, France, E-mail Address: [email protected] Search for more papers by this author , Denis Hémon French Institute for Medical Research and Public Health, France, E-mail Address: [email protected] Search for more papers by this author , Géraldine Ielsch Institute for Radiological Protection and Nuclear Safety, France, E-mail Address: [email protected] Search for more papers by this author , Christophe Debayle Institute for Radiological Protection and Nuclear Safety, France, E-mail Address: [email protected] Search for more papers by this author , Olivier Laurent Institute for Radiological Protection and Nuclear Safety, France, E-mail Address: [email protected] Search for more papers by this author , Jérôme Guillevic Institute for Radiological Protection and Nuclear Safety, France, E-mail Address: [email protected] Search for more papers by this author , Dominique Laurier Institute for Radiological Protection and Nuclear Safety, France, E-mail Address: [email protected] Search for more papers by this author , and Jacqueline Clavel French Institute for Medical Research and Public Health, France, E-mail Address: [email protected] Search for more papers by this author AbstractIntroduction A small number of large scale observational studies have reported on the association between childhood acute leukemia (CL) and exposure to natural background radiation (NBR). The objective of the present study is to contribute to document this association in France over a 20-year period.Materials andMethods An incidence study at the Communes (N=36,570) and Zones d’emploi (N=304) scales including 9,056 CL cases registered from 1990 to 2009 by the National Registry of Hematological children Malignancies and a record-based case-control study (Geocap) were performed. Subjects’ individual information of the Geocap study which compares residential exposure of cases recorded during 2002-2007 (N=2 761) to that of 30,000 contemporaneous controls representative of the French population under 15 is helpful in studying the role of NBR precluding some environmental co-exposures. NBR exposure was estimated from databases of the IRSN :1) estimates of geogenic radon potential mapped over the French territory; 2) 10,000 measurements from a nationwide survey of indoor radon concentrations and gamma exposure in French dwellings; 3) gamma-ray dose rate measured by thermoluminescent dosimeters in the 1,191 sites of the national surveillance system. NBR exposure metrics included exposure at diagnosis, cumulated exposure since birth and estimated red bone marrow dose.Results The new estimates of the distribution of NBR exposure were more precise than those used in previous analyses. No significant association was found between CL risk and any of the NBR metrics, considering either the incidence or the Geocap studies. Analyses by age, calendar period or socio-demographic characteristics did not change results. Discussion The power of the study will be investigated considering alternatives hypotheses of risk consistent with the reference risk models for low-dose ionizing radiations and compared to other nationwide published studies.