The study found a link between cell phone radiation and brain cancer.

Health professionals are struggling for decades to determine whether a cell phone can cause cancer.

Last week, the US federal government announced the end result of one of the largest and most expensive experiments in the world to investigate the matter. The study, beginning with President Bill Clinton, cost about $ 30 million, including about 3,000 rodents.

This experiment was conducted by the National American Toxicology Program and showed modestness as a positive indicator that the spread of some cell types could increase the risk of developing brain cancer in male rats.

John Bucher, chief scientist for the National Toxicology Program, said: "We believe that the link between radiofrequency and tumors in male rats is real.

However, he said, because exposure levels and durations are far superior to what humans typically find, they can not be directly compared to the exposure facing humans.

The research also investigated the effects of radio frequencies on cell phone technology in previous generations and ended up falling a few years ago without using this technology.

Therefore, all concerns derived from the study apply to people who are pioneers of mobile phone use with an abandoned model that is not a user of the current model.

Experts argue that today's billions of people are using cell phones, so even a slight rise in cancer incidence can have widespread effects.

The lowest level of radioactivity in federal research is equivalent to the maximum exposure allowed by US Federal Regulations for mobile users. This level of toxicity rarely occurs with typical cell phone use, depending on the national toxicity program. The highest level is four times the maximum.

The toxicology program announced a preliminary assessment of its findings in May 2016, which previously indicated that radiation is "a possible cause of brain tumors." In February this year, the preliminary text of the report was withdrawn from a relatively firm conclusion.

In March, a scientific review panel consisting of 11 sector and academic experts advised the IAEA to increase confidence in the results from "misleading statements" to "some indications" of associations between cell phone radiation and cell phone radiation . Brain tumor in male rats. (Rats did not show any association between radiation and tumors.)

Experts say that it's not uncommon for cancer patterns to be sex-specific in both humans and animals.

Participating rodents were exposed to radiation for nine hours a day for two hours. The exhibition began before delivery and was maintained until the age of 2 years.

Malignant glioma, a fatal brain cancer, occurred in 2% to 3% of male rats exposed to radiation for a zero sample of the control group.

On the other hand, many epidemiologists have not seen an increase in the incidence of glioma in the human population.

The study also found that between 5% and 7% of male rats exposed to the highest levels of radiation, certain cardiac tumors, known as malignant schwannomas, were zero in the control group. Malignant schwannomas are similar to neurons that are benign tumors that can occur in humans and neurons that connect the ears to the brain.

In the 1990s when the study was planned, rats were exposed to typical 900 MHz frequency radioactivity of second generation mobile phones.

Currently, cell phones are expected to be in the fourth or fourth generation, while fifth generation (fifth generation) devices are expected to be on the market by 2020. Their spread is less likely to be successful in penetrating humans and mice, scientists say.

Donald Stump, one of the participants, expressed concern that the study might "be vulnerable to criticism that it was done using old-fashioned technology."

The challenge is how to conduct experiments that are large enough to keep pace with the rapid development of the device, while at the same time delivering significant results.

Toxicologists can build a small number of exposure chambers to evaluate new technologies in a few weeks or months rather than years. Future research will focus on measurable physical indications of the potential effects of radiation, including DNA damage, that can be detected faster than cancer.