ELECTROMAGNETIC-FIELDS AND CHILDHOOD-CANC ER - STATE OF RESEARCH IN EPIDEMIOLOGY

Thirteen epidemiological studies of the relations between electromagne tic fields and childhood cancers have been published. Eleven have show n some associations between the presumed intensity of exposure to resi dential magnetic fields and the childhood cancers incidence, either fo r all cancers or for the 3 most frequent types (leukaemias, brain tumo urs and lymphomas). These associations are nor often significant becau se of the weak statistical power of these studies in relation with bot h the low incidence of cancers in childhood, and specially of each par ticular type, and the little number of subjects considered to be expos ed at a high level exposure for residential magnetic fields. All these studies fall in with the same difficulties, particularly for identifi cation and assessment of the exposure to magnetic fields and for the m anner to take into account all the potential confounders. So even sign ificant associations do not imply their causality, all the more as the carcinogenicity of extremely low frequency electromagnetic fields, al though biologically conceivable, has never been experimentally proven. Today it is impossible to claim or invalidate the influence of reside ntial magnetic fields in the genesis of childhood cancer. Setting up o f new epidemiological studies based on large number of cases issued fr om population based registries and conducted with a best defined metho dology seems to be highly desirable.