Both the US and the UK have declared a war on breast cancer, the top killer of women on both sides of the Atlantic. But even though there is much evidence to support it, few advisories on prevention discuss an emerging major cause: electromagnetic fi
This first link between female breast cancer and exposure to electromagnetic fields ironically began with studies of breast cancer in men, an extremely rare disease.
Then in 1989, Dr Genevieve Matanoski and her colleagues at the John Hopkins School of Public Health in Baltimore, Maryland, found that there was significantly more than expected cases of breast cancer among New York State central telephone technicians (The Lancet, March 23, 1990).
This was followed by studies showing that telephone linesmen, electricians and electric power workers all suffer an increased breast cancer risk (Am J Epidm, 1991; 134: 340-7), (The Lancet, 1990, 336: 1596), (The Lancet, 1992; 339: 1482-3).
In 1992, the first connection was made between EMF exposure and female breast cancer. Dr Dana Loomis of the University of North Carolina observed a 40 per cent increased mortality from the disease in female electrical workers, twice the number of deaths expected in women between 45 and 54 (J Nat Cancer Inst, 1994; 86: 921-5).
Normal background magnetic fields in most households vary between 60 and 120 nanotesla, but can be much higher in occupational settings. Some 10 studies have now found an increased risk of childhood leukemia in households with EMFs as low as 200 to 300 nT.
But the study that has prompted most interest is the recent follow-up work by Loscher in Germany, which has now confirmed a relationship between levels of magnetic field and likelihood of developing breast cancer in rats treated with a chemical carcinogen (Carcinogenesis, 1995; 16: 1199-25). The higher the magnetic field, the more likely the rats were to get cancer. His results have so impressed others that various researchers are now attempting to replicate them. The US Department of Energy has even agreed to sponsor his work directly, one of the very few times it has funded EMF research outside the US.
Despite this amount of research, the UK has no studies underway or even plans to study the EMF-breast cancer connection. It also doesn't appear to have any intention of revising its guidance for the upper limit of exposure to 50/60 Hertz magnetic fields, which is currently 1,600,000 nT-8000 times the level at which an increased risk of childhood cancer has been found in a number of studies.
One clue as to the precise mechanism by which EMFs can trigger cancer came from Loscher's rats. When exposed to 10,000 nT, the rats' nighttime blood melatonin levels decreased by one-third.
Melatonin, produced by the pineal gland, the body's master control gland and extremely sensitive to magnetic fields, is a powerful antioxidant that scavenges excessive free radicals in the body. If allowed to build up in the body, free radicals can damage DNA and increase cancer risk.
A growing number of researchers, led by Dr Russel Reiter at the University of Texas Health Science Center in San Antonio, believe that the suppression of melatonin production is the most important likely link between EMFs and all cancer (J Pineal Research, 1995; 18: 1-11).
At the 1994 annual meeting of the Bioelectromagnetics Society, Robert Liburdy, at the University of California's Lawrence Berkeley Laboratories, reported that he had observed that magnetic fields of between 600nT and 1,200nT, exposed to cultured human breast cancer cells, suppressed the anti-cancer action of melatonin, allowing cancer cells to multiply (J Pineal Reserach, 1993; 14: 89-97).
Recently, a leaked draft report on EMF exposure guidelines for extremely low frequency electric and magnetic fields by the US National Council on Radiation Protection tacitly acknowledged the danger: "Disturbance of the normal diurnal melatonin rhythm is associated with altered estrogen receptor formation in the breast, a line of experimental evidence now under study for possible links between ELF field exposure and human breast cancer. Further, melatonin has general properties as a free radical scavenger, with the possibility of a preventive role in oxidative stress, recognized as a basic factor in a broad spectrum of human degenerative disorders, including coronary artery disease, Parkinson's and Alzheimer's diseases, and aging."
In the light of this mounting evidence, everyone, but particularly women, should reduce their exposure to EMFs, both at work and in the home. Sit at least four feet from the sides and rear of VDUs (where the highest fields are emitted).
In the home, the major source of elevated fields of exposure is usually the bedroom. If you already have breast cancer, you might be well advised to check the levels of magnetic field in your bedroom overnight.
Your best protection is a diet high in antioxidants and additional intake of antioxidant nutrients A, C, E, beta-carotene and selenium.
If the UK and US governments truly wish to reduce the appalling level of female breast cancer in the West, it's time to take the harmful
effects of man-made EMFs on breast cancer development seriously.
For more information, send a sae to EM & VDU News, PO Box 25, Liphook, Hants GU30 7SE.