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Do cellphones cause cancer? Despite years of research, there is still no clear answer. But two government studies released on Friday, one in rats and one in mice, suggest that if there is any risk, it is small, health officials said. Safety questions about cellphones have drawn intense interest and debate for years as the devices have become integral to most people’s lives. Even a minute risk could harm millions of people. (Grady, 2/2)

John Bucher, a senior scientist involved in the 10-year study, was cautious in his interpretation of the results in a conference call with journalists Friday. Given the inconsistent pattern of the findings, the fact that the subjects were rats and mice rather than people and the high level of radiation used, he said, he could not extrapolate from the data the potential health effects on humans. “At this point we don’t feel that we understand enough about the results to place a huge degree of confidence in the findings,” he said. (Cha, 2/2)

"The reports don't go much further than what we had reported earlier, and I have not changed the way I use a cellphone," NTP senior scientist John Bucher said in a briefing. Dr. Otis Brawley, the chief medical and scientific officer for the American Cancer Society, said that the new evidence should not alarm wireless phone users. "The evidence for an association between cellphones and cancer is weak, and so far, we have not seen a higher cancer risk in people," Brawley said in a statement. (Kaplan, 2/2)

As part of the research, the rodents were divided into different study arms that were exposed to different levels of radiation. The lowest level of radiation they were exposed to was about the maximum level cellphones are permitted to emit, and the rodents were exposed to nine hours of radiofrequency radiation every day for two years, which Bucher made clear was much more than a regular cellphone user is going to be exposed to. “It’s a situation that allows us to express a potential biological event if one is going to occur,” Bucher said. “The message is that typical cellphone use is not going to be directly related to the kind of exposures we use in these studies.” (Joseph, 2/2)