Learn About EMFs

by Janet Raloff , www.sciencenewsonline.com 1/10/98

Melatonin, a hormone produced by the brain during periods of darkness is an important natural suppressor of breast cancer cell growth, both in test tubes and in animals. Because EMFs can depress or shut down melatonin secretion in animals, they may play a role in fostering the growth of malignancies in people.

Toxicologist Wolfgang Löscher of the School of Veterinary Medicine in Hanover, Germany, has exposed groups of up to 120 female rats to melatonin-suppressing EMFs of between 100 and 1,000 mG. An equal number of rats received a negligible background exposure of roughly 1 mG; these rats produced melatonin normally. Löscher injected into each rat a chemical that causes mammary cancer, then observed the rats for 3 months.

Compared to the unexposed rats, those in the 100-mG field developed about 10 percent more tumors, animals exposed to 500 mG got 25 percent more, and rats receiving 1,000 mG developed 50 percent more. Tumors also grew as much as twice the size under the influence of EMFs.

To understand why, Löscher has focused on the immune system’s T cells, a class of white blood cells whose role is to attack and destroy tumors and foreign substances. T cells from animals raised for 3 months in 500- or 1,000-mG fields proved only half as likely as those from unexposed rats to proliferate when exposed to a foreign substance.

“This indicates that EMFs indeed suppress the immune system’s response to ongoing processes such as tumor growth,” Löscher says.