Residential exposure to natural background radiation at birth and risk of childhood acute leukemia in France, 1990-2009

Justine Berlivet (1) , Denis Hemon (1) , Enora Clero (2) , Geraldine Ielsch (2) , Dominique Laurier (2) , Laure Faure (1, 3) , Jacqueline Clavel (1, 3) , Stéphanie Goujon (1)

1 EPICEA [CRESS - U1153 / UMR_A 1125] - Epidemiology of childhood and adolescent cancer | Epidémiologie des cancers de l'enfant et de l'adolescent
2 IRSN - Institut de Radioprotection et de Sûreté Nucléaire
3 RNHE - Registre National des Hémopathies malignes de l'Enfant

Background: The role of natural background radiation (NBR) in childhood acute leukaemias (AL) remains unclear. Several large record based studies have recently reported heterogeneous results. The different exposure period considered in these studies may explain this heterogeneity. Objectives: In a previous ecological study we did not observe any association between childhood AL incidence in France and NBR exposure at the time of diagnosis. With the same methodology, the present study focused on NBR exposure during the prenatal period. Methods: The study population included all children born in mainland France between 1990 and 2009 (French residents). Based on the French national registry of childhood cancer, we included 5,932 childhood AL cases born and diagnosed during the study period. NBR levels in municipalities of residence at birth were estimated by cokriging models, using NBR measurements and precise geological data. The incidence rate ratio (IRR) per unit variation of exposure was estimated with Poisson regression models, with adjustment for socio-demographic indicators and ultraviolet radiation levels. NBR exposures were considered at the time of birth, and cumulatively from birth to diagnosis. We also estimated a total NBR dose to red-bone marrow. We analyzed all AL together, and the main types of AL separately. Results: There was no association between NBR exposure at birth and childhood AL incidence, neither overall (gamma radiation: IRR = 0.98 (0.93,1.04) per 50 nSv/h; radon concentration: IRR = 0.96 (0,90,1.02) per 100 Bq/m3) nor for the main AL types. The conclusions were similar with the cumulative exposures, and the total red-bone marrow dose. Conclusions: The study was based on high quality incidence data, large numbers of AL cases, and validated models of NBR exposure assessment. In all, the results further support the hypothesis that NBR are not associated to childhood AL in France, whatever the timing for exposure assessment.

Mots clés: childhood cancer; leukemia; natural background radiation; radon; gamma radiation

Domaines: Santé publique et épidémiologie; Santé; Cancer; Pédiatrie; Hématologie

Justine Berlivet, Denis Hemon, Enora Clero, Geraldine Ielsch, Dominique Laurier, et al.. Residential exposure to natural background radiation at birth and risk of childhood acute leukemia in France, 1990-2009. Journal of Environmental Radioactivity, 2021, 233, pp.106613. ⟨10.1016/j.jenvrad.2021.106613⟩. ⟨hal-03212715⟩