Many scientists and environmentalists are concerned that the EMFs generated by electric appliances and high voltage power lines may harm health. Studies have not provided a clear answer to the question of health effects. Ways to reduce exposure are presented.
Can power lines and electric appliances promote brain cancer, leukemia, birth defects, and other diseases? The debate is charged with emotion.
What Are EMFs?
Electromagnetic fields, or EMFs, are electric and magnetic fields produced by electricity. Your CD player, hair dryer, television, and washing machine all use 60 hertz (Hz) alternating current (AC). The direction of the current shifts, or alternates, 60 cycles per second.
Health concerns focus on the magnetic field, measured in units called milligauss (mG). Some common appliances, like can openers and motor-driven alarm clocks, produce strong fields close up, but the field’s intensity drops off quickly a few feet away.
EMFs from 60 Hz power are “extremely low frequency,” in contrast to other radiation along the electromagnetic spectrum, such as X-rays or microwaves. Some EMFs exist naturally (e.g., the Earth’s magnetic field makes a compass point north).
EMFs from 60 Hz power can’t break apart cell barriers or heart tissue. Still, many scientists, citizen groups, and environmental activists worry about possible health problems.
Clusters of Cancer?
Concern about EMFs began in 1979 when researchers Nancy Wertheimer and Ed Leeper published a study that found a correlation between high EMFs and childhood leukemia deaths in Denver.
Electric utilities criticized the researchers’ methods. Scientists began new studies, looking at brain cancer, leukemia, Alzheimer’s disease, birth defects, and other illnesses.
Meanwhile, people living and working near high voltage electric wires and substations worried about cancer clusters concentrations of cancer within small geographic areas. Residents on Meadow Street in Guilford, Connecticut, claimed that an electric substation caused four cases of brain cancer, as well as other diseases. Teachers at Slater School in Fresno, California, said that EMFs caused at least eight cancer cases among teachers and aides working closest to high voltage transmission lines.
Journalist Paul Brodeur alerted the public with articles in The New Yorker magazine and books titled Currents of Death and The Great Power Line Conspiracy. Critics responded that cancer clusters can and do happen by chance.
Hundreds of studies have been done, costing millions of dollars. The National Council for Radiation Protection and Measurements soon will issue a 1,000 page report summarizing these studies.
Despite all these studies, there’s no clear answer. Interested parties have accused each other of selective reporting: picking and choosing data to get a particular result.
When health effects are found, scientists often are unable to replicate, or duplicate, the results in other studies. Some studies flat out contradict each other. One study found a relationship between EMFs and brain cancer, but not leukemia. Another found just the opposite.
Even if 60Hz EMFs don’t cause cancer, some scientists suspect they might promote growth of tumors that start some other way. Studies suggest EMFs slow production of melatonin, a hormone believed to fight cancer. Other studies examine whether EMFs alter the flow of calcium ions from cell to cell.
Fueling the fires are high financial stakes. Relocating transmission lines from overhead to underground would cost millions, with no guarantee that public health would benefit. And utilities and appliance manufacturers could face billions of dollars of potential liability if EMFs were ever proven to cause disease.
What Can Be Done?
While scientists debate whether EMFs pose a health risk, what can you do? First of all, keep things in perspective. Possible health problems from EMFs are rare, presenting much lower risks than many known hazards, such as the chance of an auto accident.
Yet uncertainty about even a small increased cancer risk can cause great fear. Finding out about the fields around your home can help. Some electric companies will measure EMFs with a special instrument, called a gaussmeter, free of charge.
Remember that EMF strength drops off quickly as distance from the source increases. Readings 4 inches away from a television can go up to 1 00 mG. Three feet away, the range is almost undetectable.
Using this information, Carnegie Mellon University Professor M.G. Morgan and his colleagues have suggested that people worried about EMFs use these low cost or no cost measures to reduce exposure: Move your motor driven plugin alarm clock across the room and away from your bed, or get a non motorized LED model or wind up clock. Warm the bed with your electric blanket, but turn it off and unplug it before going to sleep. Limit use of electric shavers, or switch to a manual razor. Using the best vacuum for stairs to avoid the harmful effects of EMFs. Keep the computer monitor at arm’s length and stay 3 feet away from the backs and sides of other computers. Stay at arm’s length when running kitchen appliances and other electrical equipment.
Since scientists don’t agree on whether EMFs can hurt you, neither they nor the U.S. government has determined what “magic number,” if any, is “safe.” And, since electricity is all around you, it’s a good idea to practice prudent avoidance.