Brain tumours are of different cell types, the commonest being tumours
of glia called gliomas. Many etiological factors of gliomas have been
suggested and certain industries have been implicated. Several epidem
iological studies have Linked electromagnetic fields (EMFs) to gliomas
. Health effects of EMFs have been studied, both in humans and in expe
rimental animals, mainly with negative findings. Positive experimental
evidence linking EMFs to tumours is the effect of EMFs on melatonin p
roduction by the pineal gland. Removal of the pineal gland in rats inc
reases the incidence of tumours. Further epidemiological and experimen
tal evidence is required to elucidate this possible link between EMFs
and brain tumours. (C) 1994 Wiley-Liss, Inc.