The aim of this work is to study the risk of childhood acute leukemia (AL) around French nuclear power plants (NPPs). The nationwide Geocap case-control study included the 2,753 cases diagnosed in mainland France over 2002-2007 and 30,000 contemporaneous population controls. The last addresses were geocoded and located around the 19 NPPs. The study used distance to NPPs and a dose-based geographic zoning (DBGZ), based on the estimated dose to bone marrow related to NPP gaseous discharges. An odds ratio (OR) of 1.9 [1.0-3.3], based on 14 cases, was evidenced for children living within 5 km of NPPs compared to those living 20 km or further away, and a very similar association was observed in the concomitant incidence study (standardized incidence ratio (SIR) 5 1.9 [1.0-3.2]). These results were similar for all the 5-year-age groups. They persisted after stratification for several contextual characteristics of the municipalities of residence. Conversely, using the DBGZ resulted in OR and SIR close to one in all of the dose categories. There was no increase in AL incidence over 1990-

Every year, acute lymphoblastic leukaemia (ALL) affects about 400 children aged o15 years in France,