Bad for your health.

How harmful are cell phones and what preventive measures can you take?

Conspiracies involving major government cover-ups and big business hush-ups, with the poor, innocent bystander caught in the middle, are usually the stuff of blockbuster movies.

But there is a possible danger out there. It's playing in real life and more than likely it impacts you and the lives of more than 200 million people.

With the tremendous growth of cell phone use, numerous reports have been issued regarding the potential health hazards that can come from the devices. These range from headaches, noise in the ears and stress to more terrifying reports of memory loss, DNA damage and malignant brain tumors.

These growing fears are centered on the low-powered radio signals or electromagnetic frequency (EMF) waves that are emitted by wireless phones. Emitted over the entire surface of the phone, these waves penetrate users' brains. Although scientific research and studies about the danger of EMF waves date back over the past 50 years, as yet not one study has demonstrated conclusively that EMF waves are actually harmful.

Major media hype came as a result of last fall's appearance by Dr. George Carlo, chairman of Wireless Technology Research in Washington, D.C., on ABC-TV's 20/20. WTR was established in 1993 to address the public health risks from wireless communications technologies. Its $28.2 million budget was funded by the Cellular Telecommunication Industry Association (CTIA).

The WTR study showed a correlation between a higher incidence of brain cancer and a greater risk of rare neurological tumors and DNA damage among the users of handheld phones versus users of other types of phones. However, despite Dr. Carlos findings, CTIA, the $200-billion-a-year industry trade group, maintains that "wireless phones are safe and meet the standards adopted by the U.S. government," says association president Thomas Wheeler. Quoting the World Health Organization, Wheeler says, "There is no convincing evidence that [EMF] waves induce or promote cancer."

Truth be told, every model sold in the U.S. has a specific absorption rate (SAR) rating, which measures how much microwave energy from the phone can penetrate the brain. However, according to the 20/20 report, government safety standards are vague because certain phones pass the Federal Communications Commission's safety requirements when tested in one position and fail when held in another. What harm was done all depended on how close the cell phone antenna was to the head. Held too close, as much as 60% of the microwave radiation is absorbed by and actually penetrates the brain.

The big three mobile phone manufacturers--Ericsson, Motorola and Nokia--argue that the tests were misleading and that their products meet the strictest standards set by the government. All three companies post information on their Websites regarding testing and safety issues. For more information, see www.erison.com/health www.motorola.com/rfhealth and www.nokia.com/safety.

"Wireless users are exposed to limits on SAR levels that are anywhere from 10 to 50 times below the point where any risks exist," says Norman Sandier, director of global strategic issues at Motorola Inc. in Schaumburg, Illinois. "There is a huge margin built into the phones, so that even if you exceeded the recommended safety limits, it still would not translate into any known health risks."

The fracas over cellphone dangers has driven an emerging market of devices You can equip your phone with one of these shielding devices. Three popular ones are:

* SafeTShield (formerly known as the NoDanger Protective Phone Shield), a quarter-sized mesh earpiece that claims to absorb more than 95% of the EMF waves emitted. It was developed and manufactured in Japan and distributed in the U.S. by SV1 Inc. in Pompano Beach, Florida, for $24.95 (888-256-2006, Ext. 11).

* Less EMF is a line of radiation-shielding products, including phone jackets and earpiece shields. The company claims its devices will ward off headaches, heat sensation near the ear, disorientation and irritability. The price ranges from $30 to $35 (www.lessemf. com; 888-537-7363).

* Zeropa, "The Ladybird," is a ceramic device that is attached close to the base of the antenna and protects the user from potentially harmful electromagnetic radiation in cellular phones, pagers and cordless phones. The "Ladybird" sells for approximately $35 (www.zeropa.com; 212-808-3018).

It comes as no surprise that CTIA, wireless phone manufacturers and other industry groups believe that shield-device manufacturers are preying on consumers' fear "Not only are shields or guards unnecessary from a health standpoint, they may be damaging from a technical standpoint because they interfere with the signal from the phone," says Sandier "Shields disturb transmission to the base antenna, which may cause a phone to actually boost its power in order to keep the phone call connected to the network."

Everyone from wireless phone manufacturers to industry groups to the government concedes that more research in the area of cell phone danger needs to be done. "Consumers must understand that there are several questions that still remain unanswered concerning electromagnetic waves," says Dr. Stanley Kornhauser, president of the National Institute for Electromedical Information Inc. "But the big question.., is should we take comfort in reports that evidence regarding cell phone danger is not conclusive or should we take steps to mitigate or reduce exposure to EMF waves even if the scientific jury is still out?"