MANILA, Philippines--An acquaintance was recently diagnosed to have a brain tumor. He is a sales manager who logs in at least an hour of calls made and received in his cell phone daily. He was wondering if this might have contributed to the brain tumor?s development. His tumor is in the right side of his brain and he usually places his cell phone on the right ear when he uses it.

With unlimited calls offered by the cell phone network providers at highly affordable prices, many ?especially the young,? are encouraged to use it for hours on end raising the possibility of adverse consequences with overexposure to whatever irradiation cellular phones emit.

Cell phones transmit radio frequency (RF) waves, a form of energy located on the electromagnetic spectrum between FM radio waves and microwaves. The RF waves from cell phones, like FM radio waves and microwaves are sources of radiation. But these types of radiation, called nonionizing, don?t have enough energy to directly damage the cell?s DNA. On the other hand, ionizing radiation coming from X-rays and gamma rays, could potentially damage DNA leading to cancer.

Major source

The cell phone?s antenna is the major source of RF waves. Most phones now don?t have any visible external antennas, and in these phones, the antenna is part of the body of the handheld phone. The RF waves are strongest therefore at the body part of the phone which is usually held against the side of the head when one makes or receives a call.

Theoretically, the closer the antenna, ?which is in the phone?s body,? is to the user?s head, the greater is the exposure to cell phone radiation. This is one reason hands-free devices, allowing the cell phone to be away from the head or face, is specially recommended for heavy cell phone users.

Using an earpiece moves the antenna away from the user?s head. This significantly decreases the amount of RF waves the head is exposed to. Bluetooth earpieces can also reduce potential risk for radiation to less than one thousandth the limit for cell phones as set by the US Food and Drug Administration.

Another precaution to minimize cell phone radiation is to limit duration of its use. It should only be used for urgent calls and for short durations only preferably less than two minutes. The unlimited and unrestricted usage encouraged by promotional campaigns of cell phone network providers may be exposing the users to unnecessary risks.

Studies

The studies showing no link between cell phone use and brain tumors were done with regular usage of these phones. The story might be different with excessive usage.

The scientific literature has about 30 studies evaluating possible links between cell phone use and tumors. Similar findings came out of these case-control studies, as follows:

Patients with brain tumors do not report more cell phone use compared to the controls. Surprisingly, some of the studies show a trend toward a lower risk of brain tumors among cell phone users.

There is no ?dose-response relationship??a tendency for the risk of brain tumors to increase with increasing cell phone use, although as pointed out earlier, these studies only considered usual or regular cell phone usage.

No clear link

There is also no clear link between the side of the head on which the brain tumor occurred and the side on which the cell phone was generally used.

Although current available evidence appears to be reassuring about the safety of cell phone usage, an important limitation in these studies is that they have not been able to follow people for long periods of time. Exposure to irradiation may cause development of tumors many years or even decades after the exposure. Cell phones have only been around for less than 20 years so we still cannot be sure of their possible long-term health effects.

There is also no data on the effects of cell phones in children and adolescents, who are the ones frequently using cell phones and availing of unlimited-use promotional campaigns. Theoretically, side-effects of cell-phone usage might be more pronounced in children because their nervous systems are still developing. They also have much higher total lifetime exposure than people who started using cell phones as adults. Parents should strictly regulate the cell-phone usage of their young children.

Cellular phones are now considered a necessity. One feels powerless and excommunicated without it. It is a boon to modern society but excessive usage may also be a bane for reasons we still don?t know much about.