Do cell phones lead to the formation of tumors?
In recent years there have been repeated discussions about the radiation emitted by mobile phones and the associated health risks. Researchers have now found that high exposure to radio frequency radiation appears to be related to the activity of tumors.
The scientists of the National Toxicology Program found that high exposure to high-frequency radiation in male rats leads to tumors in tissues around the nerves in the rodents' hearts. With this, the discussion about possible cancer risks of cell phone radiation has flared up again.
Radiation formed tumors in male rats
High-frequency radiation (RFR) led to the formation of tumors in male rats, but not in female rats or mice. The exposure levels used in the studies were equal to or higher than the highest value allowed for local tissue exposure to cell phone emissions. Usually, however, cell phones emit RFR values lower than the maximum permitted, the experts explain.
Effects of radiation
The incidence of tumors in the heart, known as malignant schwannomas, increased in male rats when they were exposed to RFR values that exceeded the permitted cell phone emissions, the scientists report. In addition, an unusual pattern of cardiomyopathies or damage to the heart tissue occurred in exposed male and female rats, the researchers say.
Radiation also affected other organs
The authors point out the statistically significant increase in the number of rats and mice with tumors that were found in other organs at one or more of the exposure levels examined. These organs included, for example, the brain, prostate gland, pituitary, adrenal gland, liver and pancreas. However, the researchers found that these results were ambiguous. It was unclear whether the increase in the number of tumors was related to high-frequency radiation, the scientists add.
Results should not be directly transferred to humans
The extent and duration of exposure to RFR in the study was much greater than the exposure to people from cell phone use. "So these results should not be extrapolated directly to human cell phone use," explains Dr. John Bucher in a press release on the investigation results. However, it was found that the tumors already found in previous studies are similar to those of intensive mobile phone users, the expert adds.
For the trial, the rodents were irradiated for two years
To carry out the study, the researchers built special chambers in which rats and mice were exposed to different RFR values for up to two years. The exposure concentration was between 1.5 and 6 watts per kilogram (W / kg) in rats and between 2.5 and 10 watts per kilogram in mice. The low energy level in the experiments on rats corresponded to the highest stress that is permitted today with cell phone emissions.
What radiation frequency was used?
The animals were exposed for ten minutes at ten-minute intervals, which is a little more than nine hours a day, the doctors report. The researchers used 2G and 3G frequencies and modulations, which are still used for voice calls and SMS in the United States. 4G, 4G LTE and 5G networks for streaming videos and downloading attachments use different mobile phone signal frequencies and modulations than NTP, the scientists explain.
Further effects of radiation
The NTP studies also looked for a number of other harmful effects in rats and mice, including changes in body weight, signs of tissue damage from RFR-induced warming, and genetic damage. The researchers noticed lower body weight in newborn rats and their mothers, especially when they were exposed to high RFR levels during pregnancy and lactation. However, it should be noted that these animals grew to a completely normal size.
Results can support cell phone safety studies
"These studies were complex and technically challenging, but they provide the most comprehensive assessment of the health effects of RFR exposure in rats and mice to date," says Dr. Books. Mobile phone technologies are constantly changing. The results of the study provide valuable information to support future studies on the security of mobile phones, the expert continued.
FDA called for investigation of cell phone radiation
The U.S. Food and Drug Administration (FDA) has nominated high-frequency radiation from cell phones because of the widespread use of cell phones for research. The FDA and the Federal Communications Commission are responsible for regulating wireless communication devices in the United States. (as)