Abstract
OBJECTIVE: To investigate the association between childhood leukaemia and established risk factors or other factors related to La Hague nuclear waste reprocessing plant. DESIGN: Case-control study. SETTING: Area within a 35 km radius of La Hague, Normandy, France. SUBJECTS: Twenty seven cases of leukaemia diagnosed during the period 1978-93 in people aged under 25 years and 192 controls matched for sex, age, place of birth, and residence at time of diagnosis. MAIN OUTCOME MEASURES: Antenatal and postnatal exposure to x rays and viral infections, occupational exposure of parents (particularly ionising radiation), living conditions, lifestyle of parents and children. RESULTS: Increased trends were found for use of local beaches by mothers and children (P < or = 0.01); relative risks 2.87 (95% confidence intervals 1.05 to 8.72) and 4.49 (1.52 to 15.23) when categories were aggregated in two levels (more or less than once a month). Consumption of local fish and shellfish also showed an increased trend (P 0.01); relative risk 2.66 (0.91 to 9.51) when categories were grouped in two levels (more or less than once a week). A relative risk of 1.18 a year (1.03 to 1.42) was observed for length of residence in a granite-built house or in a granitic area. No association was shown with occupational radiation exposure in parents. CONCLUSIONS: There is some convincing evidence in childhood leukaemia of a causal role for environmental radiation exposure from recreational activities on beaches. New methods for identifying the environmental pathways, focusing on marine ecosystems, are warranted.