The findings from a $25 million study, conducted over two and a half years by the National Toxicology Program (NTP), showed that male rats exposed to two types of RF radiation were significantly more likely than unexposed rats to develop a type of brain cancer called a glioma, and also had a higher chance of developing the rare, malignant form of tumor known as a schwannoma of the heart. The effect was not seen in females.
The radiation level the rats received was “not very different” from what humans are exposed to when they use cellphones, said Chris Portier, a former associate director of the NTP who commissioned the study.
As the intensity of the radiation increased, so did the incidence of cancer in the rats. (The highest radiation level was five to seven times as strong as what humans typically receive while using a phone.) Although ionizing radiation, which includes gamma rays and X-rays, is widely accepted as a carcinogen, the wireless industry has long noted that there is no known mechanism by which RF radiation causes cancer. The researchers wrote that the results “appear to support” the conclusion that RF radiation may indeed be carcinogenic.
The findings should be a wake-up call for the scientific establishment, according to Portier, who is now a contributing scientist at the Environmental Defense Fund. “I think this is a game changer,” he said. “We seriously have to look at this issue again in considerable detail.”
“The NTP does the best animal bioassays in the word,” Portier added. “Their reputation is stellar. So if they are telling us this was positive in this study, that’s a concern.”
Past animal studies have been inconclusive. Most of those suggesting a connectionbetween cellphone radiation and cancer had first exposed rodents to toxic chemicals to induce tumors, which were then shown to grow in response to radiation exposure. But the new study did nothing in advance to stimulate cancer in the animals.
The NTP first decided to investigate the carcinogenicity of cellphone radiation in 2001, partly in response to epidemiological studies showing a correlation between gliomas and cellphone use. Some of the studies even showed that the cancers were ipsilateral—meaning they tended to appear on the same side of the head where users held their phones. But other epidemiological studies haven’t found links between cancer and cellphones.
The Food and Drug Administration, which is charged with regulating the health aspects of consumer products, says on its website that there is “no evidence linking cell phone use with the risk of brain tumors.” It does acknowledge some risk associated with carrying cellphones too close to the body, but only due to the phones’ heating effect.
