There is "clear evidence" that male rats exposed to high levels of radio frequency radiation used in mobile phones developed cancerous heart tumors, the U.S. National Toxicology Program said in releasing a final report summarizing a 10-year study.
The final reports are the conclusions of NTP and a panel of external scientific experts who reviewed the studies in March after draft reports were issued in February.
Results can't be compared directly to exposure humans experience when using a mobile phone, in part because exposure levels were greater for the studied rodents, John Bucher, senior scientist with the National Toxicology Program, said in a news release.
The study involved radio frequencies long out of routine use. The tests for the study were done on rodents at levels much higher than humans are now exposed to. A =level such as this, four times higher than the maximum power level permitted, rarely if ever occurs with typical cell phone use. "In fact, we only begin to observe effects to animal tissue at exposures that are 50 times higher than the current whole body safety limits set by the FCC for radio frequency energy exposure". It's the most comprehensive analysis of the health effects in animals exposed to the radio-frequency radiation used in 2G and 3G cellphones, the researchers said.
The report leaves open the possibility that the kind of radiation produced by cellphones might have the potential to cause cancer, but it does not answer the question of how that might happen.
Interestingly, the researchers found that the male mice that were exposed to cellphone radiation actually lived longer than those that were not exposed. "This may be explained by an observed decrease in chronic kidney problems that are often the cause of death in older rats", Wyde said.
However, the RFR exposure was intermittent - 10 minutes on and 10 minutes off - totalling about nine hours each day.
Some females and some mice developed tumors, but it was mainly male rats exposed to the highest levels of radiation that developed life-threatening cancers.
In should also be noted that the types of RFR used for Wi-Fi or 5G networks were not included in this investigation. Most phones still contain antennas that can pick up these frequencies, but rely more heavily on newer generation technology like 4G LTE and 5G, which is being rolled out across the US.
'The US IEEE-FCC human safety guidelines for wireless radiation which only protect against thermal heating or burning were scientifically false decades ago, ' said Dr Paul Heroux, a McGill University physicist and toxicologist.
The toxicology agency is building smaller exposure chambers that will let it evaluate newer technologies in weeks or months, instead of years. These may include changes in metrics like DNA damage in exposed tissues, which can be detected much sooner than cancer.
But the Food and Drug Administration (FDA) insists that the danger does not apply to humans.
More information on the categories is available at https://ntp.niehs.nih.gov/results/pubs/longterm/defs/index.html.
While this suggestion has been dismissed by a number of researchers, studies undertaken over a number of years by the US National Institute of Environmental Health Sciences appears to have found evidence that, at the outset, would appear to confirm these fears.