Cellular Towers: At Watt Cost?
How dangerous is electromagnetic radiation? At the University of Washington in Seattle, Dr. Henry Lai has been conducting extensive experiments with rats to determine the effect of both thermal and non-thermal radio frequency radiation (RFR) from cellular towers and cellular phones.
Lai says his studies show that prolonged exposure to electromagnetic radiation at constant but low levels affects the nervous system, but he admits that the evidence for possible health consequences is largely inconclusive. Still, there appears little doubt that RFR at high intensities over a short period of time is hazardous.
"The stage we're at now is like the beginning of the awareness of the dangers of asbestos," says Barbara Wilson, owner of Austin Professional Wireless Communications, a company that monitors and evaluates communication towers for potential RFR hazards. "The rule of thumb is, the closer you are to the antenna, the greater the danger from power."
Wilson says high-watt towers such as the 300,000 - to million-watt television broadcast towers pose the greatest risk. Most cellular towers weigh in at 100 watts per tower and produce only 1-5% of the emissions allowable by federal law.
Steve Walz, of the Kansas-based Radiofrequency Safety International, says a new FCC licensing requirement adopted Oct. 15, 1997, requires all communications towers to comply with FCC and OSHA safety guidelines. The maximum permissible exposure standard, he says, is measured in milliwatts per square centimeters under a complicated floating scale.
In other words, there's no easy answer.
Walz says the FCC has adopted safety standards based on thermal radiation, and doesn't recognize non-thermal (magnetic, but no heat) radiation at all, which remains controversial among scientists studying the effects of cellular tower emissions. Still, thermal radiation itself can be devastating enough.
Thermal radiation "is exactly like putting a sandwich in a microwave oven," Walz says. "You stand too close and you'll heat up. As soon as you leave the area, your body recovers, but if you get 20 degrees above your ambient temperature, permanent damage is possible." Tower workers assume the greatest risk from exposure to thermal radiation, especially on rooftop towers where several antennas are mounted. Wilson says hazardous exposure to thermal radiation 200 feet or more from a cellular tower remains unlikely unless something goes wrong.
Oak Hill resident Beth DeVictoria says all members of her family have suffered from chronic headaches and tinitus (ringing in the ears), as well as fatigue symptoms she says are the result of two cellular towers near her home. She fears for her family's health, but she's come up with a solution to her immediate problem. Next year, she plans to move her family to a new home.