Like HowStuffWorks on Facebook!

Cell Phones and Cancer: No Clear Connection

Radiation Risks

Radiation Without Risk?

Like televisions, alarm systems, computers, and all other electrical devices, mobile phones emit electromagnetic radiation. The FDA can regulate these devices to ensure that the radiation doesn't pose a health hazard to users, but only once the existence of a public health hazard has been established.

In the United States, mobile phones operate in a frequency ranging from about 850 to 1900 megahertz (MHz). In that range, the radiation produced is in the form of non-ionizing radiofrequency (RF) energy. This RF energy is different than the ionizing radiation like that from a medical x-ray, which can present a health risk at certain doses.

At high enough levels, RF energy, too, can be harmful, because of its ability to heat living tissue to the point of causing biological damage. In a microwave oven, it's RF energy that cooks the food, but the heat generated by cell phones is small in comparison.

A mobile phone's main source of RF energy is its antenna, so the closer the antenna is to a phone user's head, the greater the person's expected exposure to RF energy.

Because RF energy from a cell phone falls off quickly as distance increases between a person and the radiation source, the safety of mobile phones with an antenna mounted away from the user — like on the outside of a car — has not been called into question. Also not in doubt is the safety of those so-called cordless phones that have a base unit attached to a home's telephone wiring and operate at much lower power levels than cell phones.

Many experts say that no matter how near the cell phone's antenna — even if it's right up against the skull — the six-tenths of a watt of power emitted couldn't possibly affect human health. They're probably right, says John E. Moulder, Ph.D., a cancer researcher and professor of radiation oncology at the Medical College of Wisconsin. It's true, he says, that from the physics standpoint, biological effects from mobile phones are "somewhere between impossible and implausible."

At the same time, Moulder supports further studies into the science of cell phone radiation. "Some people think the power emitted by the phones is so low, it's a silly thing to research. But I think it remains a legitimate area of study."