The National Toxicology Program recently released partial results from an ongoing $25 million, federally-funded study that appeared to show a tentative link between cellphone radiation and two rare types of tumors in male rats. Malignant gliomas in the brain and schwannomas of the heart were found to have a statistically significant tie to radiation exposure. The report hasn’t been peer reviewed because it hasn’t been formally submitted to a scientific journal and accepted for publication. The full study results aren’t likely to be published until 2017.
For the study, the researchers exposed mice and rats to radio-frequencies commonly used by wireless electronics for about 9 hours a day, 7 days a week from in utero to the age of about 2 years. Of the male rats dosed with radiation, 2 to 3 percent developed gliomas, tumors of the glial cells of the brain. Glial cells are specialized support cells that are key in the operation of the central nervous system.
Roughly 7 percent of dosed male rats developed schwannoma tumors in their hearts. These tumors affect the cells that produce myelin, which is needed by the body for a healthy nervous system. The study also found “potentially preneoplastic lesions,” which could be precancerous or benign, in the brain and heart of exposed male rats lasting throughout the rat’s lifetime. None of the non-dosed rats developed any tumors and none were reported in the dosed female rats.
The Toxicology Program felt that it was important to release the partial findings because even low incidences of cancer associated with cellphone radiation could be devastating to the populations where cellphone use is common. The study states, “Given the widespread global usage of mobile communications among users of all ages, even a very small increase in the incidence of disease resulting from exposure to [radiofrequency radiation] could have broad implications for public health.”
The study has intensified the ongoing debate regarding the human health risks of cellphone use. In 2013, the International Agency for Research on Cancer (IARC) classified cellphone radiation as a “possible carcinogen,” putting it in the same category as coffee. However, most studies examining the human population over time have concluded no association between cellphone use and increased rates of cancer. A large survey of 13,000 people in 13 countries found little or no risk of brain tumors linked to cellphone radiation.
