Should you worry about cell phones and brain cancer?

I asked myself the same question when I wrote about the link between cell phone usage and brain cancer a couple of years ago:

Each time a cell phone user makes a call, low levels of radio-frequency (RF) energy are emitted as the phone's antenna generates radio waves that transmit people's voices from one phone to another. The amount of radiation depends on how long a person stays on the phone, how he holds the phone to his head, and whether he uses it in the city or the country.

By 1996 various committees of scientists and engineers had reviewed numerous epidemiological studies and research on lab animals exposed to RF radiation. Two of these committees independently formulated exposure recommendations for cell phones. Their findings were used by the Federal Communications Commission to develop a standard for exposure, set in 1996 and still in place today. The standard - 1.6 watts per kilogram of tissue - is called a specific absorption rate.

Researchers know that cell phones don't cause cancer the traditional way by directly damaging DNA. That's because cell phones emit nonionizing radiation. In animal studies, some researchers have found that nonionizing radiation can trigger biological changes that damage DNA, which could lead to cancer. However, most studies conclude that cell phone emissions do not have the energy to cause such harm.

So why does the controversy persist? Studies trying to link a behavior to an outcome are inherently difficult.

This month, a feature story in Scientific American claimed that physics proves that cell phones don't cause cancer. Why? This is the magazine writer's reasoning:

This application of the precautionary principle is the wrong mistake to make. Cell phones cannot cause cancer, because they do not emit enough energy to break the molecular bonds inside cells. Some forms of electromagnetic radiation, such as x-rays, gamma rays and ultraviolet (UV) radiation, are energetic enough to break the bonds in key molecules such as DNA and thereby generate mutations that lead to cancer. Electromagnetic radiation in the form of infrared light, microwaves, television and radio signals, and AC power is too weak to break those bonds, so we don’t worry about radios, televisions, microwave ovens and power outlets causing cancer.

Scientifically, that makes sense.

Dr. Ann Louise Gittleman tells a different story about the dangers of electromagnetic frequencies. Gittleman told Lemondrop about how environmental pollution gave her health problems.

And Devra Davis, who wrote the book Disconnect, told Salon about the coverups of the cell phone industry and how cell phone usage is linked to "brain damage, cheek cancer, and malfunctioning sperm."

Remember when smoking was cool? Now people have lung cancer. It took a while to sort out the experimental data and decades for cancer to develop. David told Salon about the current cell phone safety debate:

We have experimental data on sperm counts. We have experimental data on brain cell damage. We have experimental data on biological markers that we know increase the risk of cancer. These are the same debates that went out over passive smoking, over active smoking, over asbestos, over benzene, over vinyl chloride.

This post was originally published on Smartplanet.com