Exposure to electromagnetic fields and human reproduction: the epidemiologic evidence

Several studies have examined the reproductive effects of occupational and environmental exposures to electromagnetic fields (EMF) using in vitro, in vivo and epidemiologic methods. The present paper reviews the main results of the epidemiologic literature on the effects of exposure to EMF on male and female reproduction, indexed in the PubMed data bank after 1990. Studies on male reproductive effects have mainly focused on the possible association between occupational exposure to EMF and infertility or congenital defects in the offspring. Studies on possible female reproductive effects have examined the association between exposures during pregnancy to EMF (VDTs, residential exposure to ELF magnetic fields, electric blankets, heated water beds, mobile phones) and spontaneous abortion and congenital defects in the offspring. For each study, the authors paid particular attention to the study design (cohort, correlational, case-control, prospective follow-up, experimental), the population and outcomes studied, the method of exposure assessment to EMF and the results obtained. Overall, the results obtained to date through the epidemiological approach, do not raise strong concern for human reproductive health from the usual occupational and environmental EMF exposure levels. However there is also some evidence that subjects with unusually high exposures, show some increase in reproductive risk. In discussing the evidence the authors point out to numerous limitations of most epidemiologic studies: confounding factors such as age, smoking, occupational exposures to male and female reproductive chemical toxicants, sedentary life stile etc. are often not taken into account. In addition, exposure of the subjects to EMF has been frequently determined only on the basis of interviews and self reports on the part of the subjects involved. These limitations are also discussed, together with the possible mechanisms of action of hypothesized/suspected reproductive effects of EMF on male and female reproduction as suggested by the literature of animal studies