A new government study is reigniting the debate over whether cellphones can cause cancer. Researchers at the National Institutes of Health found that male rats exposed to cellphone radiation for nine hours a day were more likely to develop brain cancers known as gliomas, as well as tumors in the heart called schwannomas. The longer the rats were exposed, the higher their incidence of these rare tumors, NBCNews.com reports.
Complete results from the $25 million study won’t be available until next year, but with more than 90 percent of American adults using mobile devices, the researchers decided their initial findings warranted an early release. “We felt it was important to get that word out,” says toxicologist John Bucher. “Overall, we feel that the tumors are likely to be related to the exposures.”
The study, however, produced some conflicting results. Oddly, female rats showed no effects from the radiation, while male rats exposed to radiation actually lived longer than male rats not exposed. Critics argue that research involving rats may not apply to people—indeed, brain cancer rates in the U.S. have not increased since the 1990s, when cellphones first became widespread. But Bucher said 70 to 80 percent of experts who reviewed the study concluded cellphone radiation did raise the risk of cancer in the exposed rats.