Two government tests that were part of an FDA study, blasted mice and rats with cellphone radiation.
These results have not led to Bucher's changing his cellphone habits, but he did note that the heart tumors in rats, malignant schwannomas, are similar to acoustic neuromas, or benign tumors in people in the area of the nerve connecting the ear to the brain.
The new findings are "incredibly important", says David Carpenter, a public health physician at the State University of NY in Albany who has long warned of cellphone dangers. Sex- and species-dependent increases were also observed for lymphoma, as well as cancers of the prostate, skin, lung, liver, and brain, but these findings were weaker by comparison and possibly due to causes other than radiation.
The threat that radiation from wireless devices could be a public health risk only mounts with today's report from the NTP.
An unforeseen effect of the exposure to high levels of radiation was a change in the weight of newborn rats when pregnant rats were exposed. Many studies have found no connection between the type of radiation and cancer, but the International Agency for Research on Cancer designates radiofrequency radiation as a possible carcinogen. EHT is a scientific think tank focused on preventable environmental health risks and will be publishing a series of expert reactions to the NTP technical reports this week.
While the Federal Communication Commission limits how much radiofrequency radiation can come out of your cellphone, the Food and Drug Administration can have a say about whether those limits are safe.
Researchers at the National Toxicology Program found that there was "some evidence of carcinogenic activity" from cellphone radiation in male rats. In real life, humans are exposed to cellphone radiation at a rate that is "very, very, very much lower than what we studied". While the United States has transitioned to 4G, 4G-LTE and 5G networks in recent years, the 2G and 3G frequencies are still used in voice calls and texting. Most groups were exposed to nine hours of radio waves per day for two years. Therefore, the results may not be applied directly to humans, according to John Bucher, a senior scientist at the National Toxicology Program.
Though Dr Bucher says the levels of microwave radiation the animals were exposed to were much higher than we encounter from our cell phones, humans are, of course, considerably larger than rats.
And even with these unusually high levels of exposure, the links to cancer were still "mostly equivocal, or ambiguous", according to the FDA's statement.
The voluminous but sometimes puzzling results also aren't likely to prompt USA agencies or other bodies to immediately change how they regulate the ubiquitous devices or view their health risks. The difference could simply be the result of chance, STAT News reports. And just because researchers discover an association in rodents does not mean they translate to humans.
The reports, along with earlier research show that current limits for mobile phone radiation, "remain acceptable for protecting the public health", Jeffrey Shuren, director of the FDA's Center for Devices and Radiological Health, said in an emailed statement.