Cell phone use linked to brain cancer in rats: US study

A multiyear, landmark study conducted by the United States government finds a link between mobile phone use and cancer, according to a report released Friday, which reignites a debate about devices and health.

Conducted by the Department of Health's National Toxicology Program, the study involved several hundred rats.

According to the results, 11 out of 550 male rats developed brain cancer tumors after long-term exposure to the types of radiation, GSM and CDMA, most commonly utilized in the U.S.

In another group of 669 male rats, nine developed non-cancerous heart tumors when exposed to mobile phone radiation.

The same experiment was performed on female rats, but rates were much lower. Three developed brain cancer tumors while six developed a similar type of tumor in the heart.

A control group of rats that were not exposed to the radiation developed no brain or heart tumors.

In two years, the radiated rats were exposed to the cellphone radiation 18 hours a day for seven days a week. But researchers were switching the radiation on and off every 10 minutes, so the rats directly received only about nine hours of radiation each day.

“Our studies are designed specifically to mimic the human exposure scenario,” said lead study author Michael Wyde in a statement.

While the study doesn't establish a conclusive link between cancer and mobile phones, it rekindles a longstanding debate, even though the health effects of cellphones have never been substantiated in a laboratory.

Almost all of the research about radiation's effects on health involve high levels of radiation, but not the extremely low levels emitted by cellphones.

Even though the amount of radiation is low, most mobile phone users are continually exposed to it. More than 90 percent of Americans own a cellphone, the report said and, 4.6 billion people across the globe possess one, according to estimates from research firm Statista.

Brain cancer is still rare, though, with less than 20,000 Americans dying of the condition, according to the American Cancer Society.

Rates have not increased significantly since mobile phones were widely introduced in the 1990s.