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High Cost Of Convenience
STRICT FEDERAL STANDARDS AND YEARS OF RESEARCH HAVE NOT ENDED NAGGING UNCERTAINTY ON WHETHER PRESSING A CELL PHONE AGAINST THE HEAD POSES A LONG-TERM HEALTH HAZARD.
Wireless phones are convenient, easy to use and increasingly affordable, which explains why more than 103 million people in the United States are carrying them around.
But are they safe?
Despite years of research and a strict federal standard for all wireless phones, a nagging uncertainty remains about whether pressing the tiny phones against the head poses a long-term health hazard.
The reason is that the radio waves that make wireless communications possible also produce electromagnetic energy fields and heat that can change or damage tissue under certain circumstances.
Although the research has not proved that wireless phone use causes health problems such as cancer, brain tumors or DNA damage, researchers and the industry agree that more long-term studies are needed.
"Currently the scientific literature relating to the health effects of low level exposure to [radio frequency energy] does not demonstrate the existence of any health risk from wireless phones," said a research agreement signed in June between the U.S. Food and Drug Administration and the Cellular Telephone Industry Association.
"Little is known, however, about the possible health effects of repeated or long-term exposure to low level [radio frequency energy] of the sort emitted" by wireless phones, the agreement said.
A finding that wireless phones are harmful, however, could have far-reaching impact.
The potential health threat from both analog and digital phones stems from the very heart of wireless technology: radio waves. When you use a wireless phone, low-energy radio waves carry your voice to a local antenna site that, in turn, relays the conversation by radio wave to the recipient. The same antenna relays the response back to your wireless phone. A computerized system monitors each call and ensures that the phone always receives the strongest available signal.
The radio waves produce electromagnetic energy, called radio frequency or RF energy, or radiation. Unlike X-rays, radio frequency radiation is non-ionizing, which means it does not alter the chemical structure of matter when it is absorbed. Instead, the energy is usually absorbed as heat.
It has been known for many years that exposure to high levels of RF radiation can be harmful because it can heat biological tissues rapidly. This is the principle by which microwave ovens cook food.
According to an August 1999 Federal Communications Commission bulletin about the biological effects and potential hazards of radio frequency electromagnetic fields, tissue damage in humans may occur during high exposure because of the body's inability to cope with or dissipate excessive heat.
Wireless telephone handsets produce low-level RF energy. Nevertheless, in August 1996, the FCC adopted a lower standard to minimize the thermal exposure of wireless phone users, measured by the "specific absorption rate," or SAR, in watts per kilogram.
Any wireless phone for use by the public must not exceed an SAR of 1.6 watts per kilogram. The partial-body standard is measured over 1 gram of tissue. A partial-body limit is used because the ear and head are most exposed to the energy fields when a phone is pressed against the head.
The standard is intended to protect all wireless users from being exposed to unhealthy thermal effects, regardless of the length of their call, when they use the phone the way it was intended.
"The standard we're using should be protective of everybody," said Robert F. Cleveland Jr., senior scientist for the FCC's Office of Engineering and Technology. "It's a continuous exposure limit."
Every phone approved by the FCC since August 1996 has had to meet those exposure limits. And since Sept. 1, any phone marketed in the country must also meet the limit, even if it was manufactured before 1996.
The FCC's standard, which is stricter than the limit used in most of Europe, was based on the recommendations and exposure guidelines of the private Institute of Electrical and Electronics Engineers and the National Council on Radiation Protection and Measurements.
It has since been adopted by the federal Environmental Protection Agency and the FDA.
The exposure guidelines of the professional membership organizations were based on the latest research, and they are continually being re-evaluated in light of new findings, Cleveland said. The new FCC standard replaces one that went into effect in 1985 and that was five times more lenient.
But scientists disagree whether even the new standard is adequate. Some research studies have suggested that there might be DNA damage or other health effects--such as changes in cell proliferation, brain waves and the body's immune response--from radiation exposure below the level that the standard says is safe.
Researchers in Britain also raise the possibility that children might be at greater risk from RF radiation because of their developing brains.
"Those results haven't been confirmed," Cleveland said. "But follow-up studies are trying to replicate those effects."
The wireless industry, which spent more than $28 million on a five-year round of studies conducted by third-party researchers, signed another agreement in June with the FDA to follow up on the earlier findings.
The research, which will be conducted over the next three to five years, will include both laboratory and field studies of wireless telephone users. It will be paid for by the industry but conducted under government oversight.
In addition, 16 countries, the European Union, the World Health Organization and phone manufacturers such as Schaumburg-based Motorola Inc. are reviewing existing research or doing new studies.
The goal is to answer lingering questions about the hazards of RF energy from wireless phones. Meanwhile, the Cellular Telecommunications Industry Association, a trade group, is requiring that any phone it certifies provide information about SAR levels on its packaging by early next year.
The manufacturer must say on the box that the phone meets the FCC's guidelines and provide the identification number that consumers need to find more information on the FCC Web site about the phone's specific SAR.
Inside the box, the manufacturer must include information about SAR and the phone's specific rating.
Factors that influence the SAR include whether the signal is analog or digital, the frequency on which the call is transmitted and the phone's design.
The FCC-required tests are done at maximum power, even though in actual use, phones typically operate at power levels between 25 percent and 50 percent. The wireless phone industry says that differences in SAR values between phones do not mean that the phone with the lower SAR value is necessarily safer.
Cleveland, at the FCC, agrees. "If the SAR is below 1.6 [watts per kilogram], it's going to be safe," he said.
But some consumers may be more comfortable with the lowest possible rating. "Everybody has their threshold for perceived risk; it's just a matter of personal philosophy," he said.
For consumers who want to minimize any possible exposure to RF energy until more research is completed, the FDA suggests limiting conversations on hand-held wireless phones and making greater use of telephones with vehicle-mounted antennas, in which there is a greater separation between the user and the radiating antenna.
Other suggestions include using headsets rather than holding the wireless phone next to your head and limiting the number or duration of the calls you make.
Aegis Note: As it relates to the following paragraph, AegisGuard LS Radiation Shields are the only shielding product that deflects, rather than absorbs, radiation.
Radiation-dampening covers might not be effective. In a recently revised fact sheet, the World Health Organization said the "scientific evidence does not indicate any need for radio frequency-absorbing covers or other absorbing devices on mobile phones. They cannot be justified on health grounds and the effectiveness of many such devices in reducing RF exposure is unproven."