Nature's Backyard
Home of the Brave New Composter
Home of the Brave New Composter
BOSTON -- Women who work with equipment generating strong magnetic fields may be at greater risk of developing breast cancer, a new study concludes.
But according to the study, led by researchers from the Boston University Medical School, the increased risk was modest and further work was needed.
High-risk jobs included electrical engineers, computer equipment operators, working with fluorescent lights and operators of mainframe computers.
Women who use personal computers or word processors would not have the high degree of exposure found to increase the risk of breast cancer.
"Working in front of a screen did not increase your exposure that much," said Dr. Patricia F. Coogan of the Boston University Medical School.
The study, to be published in the September issue of the journal Epidemiology, also involved researchers from Illinois, New Hampshire and Wisconsin.
It compared 6,888 women diagnosed with breast cancer between 1988 and 1991 with 9,529 women with no history of breast cancer.
An industrial hygienist ranked the women's jobs for potential exposure to magnetic fields.
The study found that women whose jobs exposed them to high levels of magnetic fields, 60 hertz or greater, had a 43 percent greater chance of being diagnosed with breast cancer than those whose jobs exposed them to minimal levels.
"At this point in time, we should be prudent about exposures," Dr. Coogan said.
In an editorial, Susan Preston-Martin of the University of Southern California, said the study "is the latest in a series of ambiguous epidemiologic studies that indicate, weakly, that occupational exposure to magnetic fields increases breast cancer risk."
A study reported in the Journal of the National Cancer Institute in 1994 had finding similar to those in the new study.
Magnetic fields, created when currents flow through wire coils, may affect the pineal gland, located in the head, which produces melatonin, Dr. Coogan said.
Melatonin inhibits the body's production of estrogen, which is believed to cause breast cells to grow faster, increasing the risk of breast cancer.
Experiments with rodents found their production of melatonin dropped when they were placed in magnetic fields.
But Stephanie London, an epidemiologist with the National Institute of Environmental Health Sciences in North Carolina, said there is conflicting evidence whether magnetic fields have that effect on human beings.
She said the new study on magnetic fields and breast cancer "inches us a little bit further toward saying there might be something there."
Three other studies now being made should result in more answers during the next few years, she said.
| -Top- | -Home- | -Digest- | -Index- | -Staff- |  |