Two new reports suggest that women already subject to factors that decrease their secretion of the hormone melatonin may experience small further reductions in response to the electromagnetic fields (EMFs) in their homes. On the broader issue of whether EMFs affect melatonin secretion in general, the studies contradict each other.
Melatonin, which is secreted mainly at night by the brain's pineal gland, has been shown in animal studies to suppress the growth of mammary tumors. The researchers who conducted these studies ask the question, Do EMFs acting on people as they sleep lower the secretion of this hormone?
EMFs, which are ubiquitous in industrialized countries, emanate from electrical currents in power lines, wires, and appliances (SN: 8/21/93, p. 124). Although some laboratory studies have shown biological effects of EMFs (SN: 1/10/98, p. 29), studies of people exposed to elevated EMFs over short periods have failed to find any consistent effect.
A pair of