The 10-year, $25 million toxicological studies are the most comprehensive assessments to date of health effects and exposure to radio frequency radiation in rats and mice, according to the online notice from the National Institute of Environmental Health Sciences, a unit of the National Institutes of Health, the U.S. medical research agency.
High exposure to radiofrequency radiation (RFR) in rodents resulted in tumors in tissues surrounding nerves in the hearts of male rats, but not female rats or any mice, according to draft studies from the National Toxicology Program (NTP).
However, in an emailed release, Bucher said the tumours observed in the studies "are similar to tumours previously reported in some studies of frequent cellphone users".
US researchers spent almost two decades to design and carry out a definitive study on the health effects of cellphone radiation. Unfortunately, not even today, nearly 20 years after, the pieces of evidence that link cell phone radiation to cancer are not conclusive and scientists can't make the connection between daily cell phones use and brain cancers cases.
Unlike ionizing radiation such as that from gamma rays, radon and X-rays, which can break chemical bonds in the body and are known to cause cancer, radiofrequency devices such as cellphones and microwaves emit radiofrequency energy, a form of non-ionizing radiation. Due to this, the rats had developed tumors around their hearts.
While the drafts of these studies are yet to be reviewed by other scientists, the FDA (Federal Communication Commission) limits the amount of radiofrequency radiation that can come out of the cellphones. So the FDA asked the National Toxicology Program (NTP), a division within the National Institutes of Health, to investigate.
The findings about the rare nerve-tissue tumor discovered in the hearts of male rats do not translate directly into a concern for humans, Bucher said.
Consumer Reports health and safety experts believe that while the evidence is still far from clear, the new findings highlight the need for continued research into the possible effects of cell phones on human health, and underscore our longstanding advice to follow some basic precautions when using the devices. More recent 4G, 4G-LTE, and 5G networks for streaming video and downloading attachments use different cell phone signal frequencies and modulations than NTP used in these studies.
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. But they also lived longer.
'Even with frequent daily use by the vast majority of adults, we have not seen an increase in events like brain tumors, ' he said in a statement. The difference could simply be the result of chance, STAT News reports.
"The levels and duration of exposure to RFR were much greater than what people experience with even the highest level of cell phone use, and exposed the rodents' whole bodies".
Dr. Otis Brawley, chief medical officer of the American Cancer Society, noted that the studies were negative for common tumors. "I am actually holding my cellphone up to my ear".