[Synthesis of the epidemiological evidence concerning childhood leukemia in relation to exposure to 50 Hz. electric and magnetic fields].

A review of epidemiologic evidence concerning the association between childhood leukaemia and exposure to 50 Hz electric and magnetic fields is presented, with special reference to fourteen studies published between 1979 and 1997 that utilised different systems of exposure assessment. While spot measurements of indoor magnetic fields were not associated with childhood leukaemia, combined relative risks from studies using 24 hour measurements range from 1.3 to 1.6 with lower confidence limits > or = 1.0. Thus, epidemiologic studies support an association between exposure to 50 Hz magnetic fields and childhood leukaemia. However, the causal nature of the association does not appear conclusively demonstrated because of limitations in study design and lack of a plausible biologic mechanism. In this framework, it seems justified to recommend the adoption of preventive measures aimed at reducing exposure to magnetic fields in dwellings, particularly in those featuring relatively high exposure levels.