Article on Electromagnetic Fields published in Medical Electronics:
A Survey of present knowledge concerning low-frequency electromagnetic radiation from power lines, home wiring, appliances, televisions and computer displays

EPA SAYS THREAT IS REAL

By 1990, over one hundred studies had been conducted worldwide. Of these, at least two dozen epidemiological studies on humans indicated a linkage between electromagnetic radiation and serious health problems. In response to public pressure, the Environmental Protection Agency (EPA) began reviewing and evaluating the available literature. In a draft report issued in March, 1990, the staff of the EPA recommended that magnetic fields be classified as a Class B carcinogen. This category is for "probable human carcinogens," and includes formaldehyde, DDT, dioxins and PCBs. However, in a later watered-down revision, the reference to Class B was deleted, and the following explanation was added:

Curiously, this rather unusual logic appears on the very same page as the following: "In conclusion, several studies showing leukemia, lymphoma, and cancer of the nervous system in children exposed to magnetic fields from residential 60 Hz electrical distribution systems, supported by similar findings in adults in several occupational studies also involving electrical power frequency exposures, show a consistent pattern of response that suggests a causal link."

RECENT STUDIES RAISE CONCERN

Until a few years ago, the electric and magnetic fields around power lines, electric motors and household appliances were thought to be harmless. However, on the basis of new studies, scientists are changing their opinions. As reported in the Wall Street Journal, "recent research with human cells and laboratory animals, plus epidemiological studies, all have suggested that the fields do have biological effects, and that they may foster a number of medical problems, including cancer and miscarriage. Leonard Sagan, the radiation expert at the Electric Power Research Institute, says that the latest experiment is important because 'this is humans, not rats, who are apparently showing an effect'."

As early as 1976, scientists in Loma Linda demonstrated that exposure to weak levels of EMF could slow the outflow of calcium in cells from chicken brains. A major study of chicken embryos, sponsored by the Environmental Protection Agency and the U.S. Navy, found a significant increase in abnormal embryos of chickens when exposed to pulsed magnetic fields similar to the type of magnetic fields emitted by VDTs. Of six laboratories, two found a statistically significant increase in abnormal embryos, and three found non-statistically significant increases. Such abnormalities included lower birth weights and birth defects.

One of the earliest studies on the human health effects of EMF was conducted in the greater Denver, Colorado area by epidemiologist Nancy Wertheimer and physicist Ed Leeper. Using data on children who had died before age 19 of cancer between 1950 and 1979, this study found significant excess risks among children who resided in homes close to heavy duty distribution lines. Other studies indicate that these lines typically produce strong magnetic fields.

In 1982, the New England Journal of Medicine published a letter from Dr. Samuel Milham, Jr. describing his study of leukemia deaths in Washington state. His comprehensive study, which examined the data for 438,000 deaths occurring between 1950 and 1979, found that leukemia deaths were elevated in 10 out of 11 occupations involving exposure to EMF. In 1988, epidemiologist Dr. David Savitz set out to disprove the results of the earlier Denver study using a different group of children. Instead, his findings were nearly identical with the first study F indicating elevated risk for all cancers among children living in homes near power lines with magnetic fields at or above 2 milliGauss (mG).

Perhaps the most publicized study was conducted in 1988 by the Kaiser Permanente HMO in Oakland, California, one of the largest health care facilities in the country. Kaiser's researchers tracked 1,583 pregnancies to find out whether pregnant women had been affected by the widespread use of aerial spray to kill medflies. No problem was found with the spraying, but the researchers were surprised to find a statistically significant 73% increase in miscarriages in working women using CRT-style VDTs (cathode ray tube style video display terminals), compared to other working women. The study also found an increase in birth defects, although the result was not statistically significant due to the sample size.

The National Institute for Occupational Safety and Health (NIOSH) captured world-wide headlines in the spring of 1991 when it released the results of its study on the health effects of CRT-style VDTs and miscarriages. The study found no link between VDT use and miscarriages, after studying 730 pregnant directory assistance and general telephone operators. The study concluded that "the use of VDTs and exposure to the accompanying electromagnetic fields were not associated with an increased risk of spontaneous abortion in this study" (emphasis added).

Unfortunately, a close examination of the NIOSH report (published March 14, 1991, in The New England Journal of Medicine) shows that the media's interpretation was incorrect, and that the study's conclusions were limited. One group (the study population) of operators used CRT-style VDTs, and another group (the control group) of operators used a different type of video display, with either LEDs (light emitting diodes) or neon glow tubes. Interestingly, measurements of abdominal exposure to ELF magnetic fields were similar for both groups. Hence, the study reached no conclusions about health risks to pregnant women from the ELF radiation emitted by VDTs, although NIOSH attempted to minimize this major flaw by stating that the levels of abdominal exposure to ELF for both groups were in the same range as exposures in the home (i.e., .5 mG to 2.5 mG).

Other studies have yielded alarming results. A Johns Hopkins study showed that the incidence of leukemia among telephone cable workers was 7 times greater than among other telephone company employees. A subsequent study of 1.5 million past and present employees of AT&T found that men working as cable splicers and central office technicians had 1.7 times the risk of dying from leukemia than men working at jobs with less exposure to EMF. This is startling, considering that the field these men are exposed to is, on the average, relatively low (4.3 milliGauss.) As John Monahan of the Food and Drug Administration explains, "the effect is real. It is produced by a low-level magnetic field.

Studies of cells and laboratory animals exposed to EMF show biological effects, including: changes in levels of neurotransmitters F the chemicals which send signals between nerves, changes in levels of calcium found inside or on the surface of cells, embryo abnormalities in chickens, mice and pigs, malignant lymphomas in mice exposed to very high-intensity EMF, slowing of repetitive learning and reduced testical weight in rats, changes in brain chemistry, heightened stress, and changes in the rate of growth and cell division of some cells. The latter effects have implications for the offspring of pregnant women and growing children.

In some experiments, human cancer cells exposed to EMF exhibit increased resistance to attack by the body's cancer fighting white blood cells and the body's immune system. Further, a drop in the levels of melatonin have been reported in people sleeping with electric blankets. Melatonin is a hormone which controls the monthly female cycle and inhibits the growth of certain cancers. Other experiments on humans indicate that EMF can cause fatigue, headache, slower reaction times, slower heart rates and altered brain waves.

A study released in February, 1991 by the University of Southern California (USC) Los Angeles unexpectedly found an increased rate of leukemia among children who watch black and white televisions. While the study is the first to make this link, it is a reminder to keep children as far back from a television as possible. This study also found that exposure to hair dryers, curling irons and electric blankets increased the risk of getting leukemia.

In addition to leukemia in children, more recent studies have linked EMFs with new diseases. Loomis and Savitz of the University of North Carolina reported a doubling of the expected breast cancer rates for women in electrical trades aged 45-54. (Microwave News, Nov/Dec 1993). More recently, a major study linked EMFs with Alzeimer's. Results from two studies conducted in Finland and one in Los Angeles indicate that people with a high occupational exposure to EMF's are at least three times as likely to develop Alzeimer's disease a those without significant exposure. (Network News, Aug/Sep 1994).

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