Once again, science tells us that cell phones do not cause brain tumors

Once again

The body of evidence that cell phone use is not related to the onset of brain tumor is further expanding. The issue, which has long been the subject of debate within the scientific community, has recently returned to the headlines after the launch of 5G, the new generation mobile network. Today's news is that a new study, conducted by a group of researchers at Oxford Population Health and the International Agency for Research on Cancer (IARC), shows, in essence, that there is no increased risk of contracting cancer at the brain following the use of the mobile phone. The work was published in the Journal of the National Cancer Institute.

Some context The electromagnetic spectrum, that is the set of frequencies of electromagnetic waves, precisely those emitted by mobile phones (but not only: any object that works on electricity, from vacuum cleaners to lamps fluorescence, emits electromagnetic waves), is divided into ionizing radiation and non-ionizing radiation. Exposure to ionizing radiation, for example those of X-rays, has a notoriously carcinogenic effect, which has long been known to the scientific community.

Cell phones, on the other hand, emit non-ionizing radiation, with frequencies between 30 kilohertz and 300 gigahertz: for these frequencies, according to what is reported for example by the National Cancer Institute, there is currently no solid evidence of correlation with increased cancer risk. The only recognized biological effect, again according to the same source, could be the overheating of the tissues in the immediate vicinity of the source that emits the waves: in other words, putting the mobile phone close to the head, and keeping it on it for a fairly long time, causes a local heating (which, however, has no measurable effects on body temperature), the consequences of which on health, however, are not clear.

Furthermore, according to some there is the possibility that the energy of radio frequencies has consequences on glucose metabolism, even if - yet - there is no clear evidence on this: if a study has indeed shown a an actual increase in glucose metabolism in the region of the brain near the ear on which the cell phone usually rests, another showed, in the same region, the diametrically opposite effect, ie a reduction in glucose metabolism. Too many inconsistencies to be able to draw a definitive conclusion on the matter.

Cell phones and cancer As far as cancer is concerned, the question is even more complicated. As we told you, various tests seem to show that radio frequencies do not induce any damage to DNA (which, in cascade, would be responsible for the onset of cancer). A study conducted on mice by the National Institute of Environmental Health Sciences (Niehs), which is part of the US National Institutes of Health (Nih), suggested that there is no evidence "of a relationship between cell phone use and cancer. ”, Particularly for malignant brain tumors, such as glioma, and benign, such as neuroma and meningioma, although the authors describe some possible correlations (but not cause-and-effect relationships) for certain subgroups of people.

Another work, published in 2016 in the journal Cancer Epidemiology and relating to a group of about 30 thousand Australian patients affected by a brain tumor over the thirty-year period 1982-2012, showed that the increase in of cell phones is unrelated to a proportional increase in brain tumor diagnoses, which remained stable in women and increased by 0.05% in men. On the other hand, there are also opposite results. The Hardell study, a large survey conducted in Sweden over ten years ago, for example showed a correlation between cell phone use and the onset of astrocytoma and acoustic neuroma; and the Interphone study highlighted an increased risk of developing glioma for those who had spent more than half an hour a day on their cell phones for the past ten years.

A methodological problem Part of the difficulty is that it is not easy to assess the effects of radiation exposure afterwards. If we focus, for example, on brain cancer patients, and try to understand how and how much they have used cell phones in the past, we can expect problems in data collection: "In studies conducted in this way - Cancer Research Uk experts commented on this - researchers ask people with and without cancer to remember how and how much they used the mobile phone: such an assessment, inevitably, is not very precise, especially since those who suffer brain cancer may also have memory problems ”.

In any case, based on the principle of maximum precaution, IARC has decided to prudently include radio frequencies among the factors "possibly related" to the onset of cancer. And they will probably stay there until more definitive certainties are obtained.

Today's study Meanwhile, science has moved on. And so we come to today's study, whose authors drew on the UK Million Women Study, a database that contains the health data of a quarter of women born in the UK between 1935 and 1950. As they explain at the University of Oxford, in 2001 around 776,000 people answered a questionnaire containing questions relating to their use of mobile phones. Half of them were interrogated again in 2011, and all were monitored for a period of 14 years, referring to data entered in the databases of the English health system.

Scientists, in particular, have tried to cross-reference data relating to cell phone use with the risk of developing various cancers, including glioma, acoustic neuroma, meningioma, gland tumor pituitary and eye cancer. The most important finding is that "there was no significant difference in the risk of developing cancer between women who had never used a cell phone and cell phone users", and that "there was no increase in the risk of developing any type of these cancers in women who reported using cell phones every day, talking on the phone at least 20 minutes a week and / or using a cell phone for the past ten years ”.

Again: the incidence of tumors on the right and left side of the head is very similar, although those who use a mobile phone tend to place it more frequently on the right side of the head. "These results - commented Kirstin Pirie, of Cancer Epidemiology Unity at Oxford Population Health - consolidate the evidence that the use of cell phones, under normal conditions, does not increase the risk of developing brain tumors". The expression "under normal conditions" suggests that, in the absence of further evidence, and always referring to the principle of maximum precaution, those who use the mobile phone very intensively would still be better off using earphones or speakerphones to avoid keeping it leaning on his head for too long.