In recent twenty years electromagnetic fields stirred up considerable public interest. There are many opinions on their adverse health elfects. The present state of knowledge indicates that health hazard due to human exposure to electromagnetic field in the natural environment is only hypothetical: in the worst case it is slight. So far, there have been no reported incidences of illness caused by the electromagnetic field. Most study results indicate that the electromagnetic field occurring in the natural environment is not a mutagenic factor. Studies on the effects of electromagnetic fields on the living organisms have not been carried out sufficiently long, and further investigation is required.