Initial findings from a massive federal study released on Thursday suggest that radio-frequency (RF) radiation, the type emitted by cellphones, can cause cancer, Mother Jones reported Friday.
Chris Portier, former associate director of the National Toxicology Program (NTP), which commissioned the study, said the findings should be a wake-up call for the scientific establishment, he told Mother Jones.
"I think this is a game changer and we seriously have to look at this issue again in considerable detail," he was quoted as saying.
The $25 million study, conducted over two-and-a-half years by the 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 a rare, malignant form of tumour known as a Schwannoma of the heart.
The study is significant because the radiation levels the rats were exposed to was "not very different" from what humans are exposed to when they use cellphones.
The rats were exposed to the RF radiation frequencies used by second generation (2G) phones for nine hours a day, for a period ranging from two months to the lifetime of the rat.
According to the article, of about 25,000 malignant brain tumours diagnosed each year in the United States, 80% are Gliomas. Malignant brain tumours are the most common cause of cancer deaths in adolescents and adults aged 15 to 39 years.
Most of past animal studies that suggested a connection between cellphone radiations and cancer were performed on rodents. However, in those tests, the rodents were first exposed to tumour-inducing toxic chemicals, which then grew in response to radiation exposure.
The NTP study was different and did nothing in advance to stimulate cancer in animals.
NTP had first decided to study the carcinogenicity of cellphone radiation in 2001.
Some studies found that cancer tends to appear on the same side of the head where users hold their phones. A Danish epidemiological study, however, showed no link between cellphone use and cancer.
The NTP study, though, does not mention how these results might translate into cancer risk for humans but said that given the massive number of wireless communication device users, these results might leave an impact on the public health.
The wireless industry and media outlets like tech sites have proclaimed that the science behind cell phone use and safety is a settled issue.