US National Cancer Institute Response

NCI Statement: International Agency for Research on Cancer Classification of Cell Phones as“Possible Carcinogen”

3 June 2011

The World Health Organization’s International Agency for Research on Cancer (IARC) today classified mobile phone use and other radiofrequency electromagnetic fields as a possible carcinogen (group 2B). This is neither new research nor at odds with previous findings.

Both IARC and NCI recommend continued monitoring of both brain cancer trends and new evidence from studies in humans and laboratory animals. In particular, it will be important to assess risk after long-term use, and for younger users. IARC further recommends specific actions to reduce exposure (e.g. hands-free use and texting) as further studies are undertaken. 

Interphone, considered the major study on cell phone use and cancer risk, has reported that overall, cell phone users have no increased risk of the most common forms of brain tumors -- glioma and meningioma. In addition, the study revealed no evidence of increasing risk with progressively increasing number of calls, longer call time, or years since beginning cell phone use. For the small proportion of study participants who reported spending the most total time on cell phone calls, there was some increased risk of glioma, but the researchers considered this finding inconclusive. Furthermore, a large population-based cohort study in Denmark has found no evidence of increased risk of brain tumors. It is noteworthy that brain cancer incidence and mortality rates in the population have changed little in the past decade.

The National Toxicology Program (NTP) at the National Institute of Environmental Health Sciences is leading the largest laboratory rodent study to date on cell phone radiofrequency exposures. The NTP studies will assess the potential for health hazards from exposure to cell phone radiation. The studies are designed to mimic human exposure and are based on the frequencies and modulations currently in use in the United States.