The IARC (International Agency for Research on Cancer research ) under the WHO (World Health Organization) has issued a report prepared by a group of 31 experts from 14 countries in which they classify radiofrequency electromagnetic fields as a carcinogen (agent or substance that can cause cancer) of group 2B. The use of cell phones is included within the categories of exhibition to radiofrequency electromagnetic fields.

IARC classifies population carcinogens into 5 groups: group 1: human carcinogens; group 2A: probable carcinogens; group 2B: possible carcinogens; group 3: carcinogens not determined; and group 5: probably not carcinogens.

Among other carcinogens, the occupational exhibition of carpenters, dry cleaners and firefighters, coffee consumption, inhalation of gasoline or engine exhaust, administration of certain antibiotics (metronidazole) and progestogens are considered carcinogens that are included in group 2B, as is exhibition to electromagnetic fields.

Although there are multiple epidemiological programs of study designed to investigate the relationship between the use of mobile and the development of brain tumors, none of them has demonstrated with robust scientific evidence such association. The results of these programs of study are contradictory. An American study conducted in 19 states analyzed the relationship between the issue of cell phone contracts and the incidence of brain tumors. The authors indicate that the use of mobile (or at least the existence of a cell phone contract) is associated with a higher incidence of brain tumors. Criticism of this publication has focused on the epidemiological design , as a strong positive association can also be observed between brain tumors and the issue of hospitals or the issue of beauty salons counted in each state.

In a multicenter study called Interphone, sponsored by IARC itself, it was reported that regular cell phone users paradoxically had a lower risk of gliomas or meningiomas (two types of brain tumors) than the non-user population, a surprising conclusion, probably due to a bias in the participation of the population studied or other methodological limitations.

The same Interphone study identified a subgroup of the population called "heavy" users (users who use mobile 30 minutes a day for a period of 10 or more years) in which a 40% increased risk of gliomas was observed.

The significant increase in the intensity and quantity of mobile use in the world population, the decrease in the age average of users, and the data of other programs of study yet to be published from the Interphone study, to which group of experts have had access, were the main reasons for classifying electromagnetic fields as "possible" carcinogens.

The inclusion of cell phone use as a possible carcinogen (group 2B) means that it has a limited level of evidence, i.e., a positive association has been observed between exhibition to the agent and cancer, but other factors such as chance, bias or other confounding factors cannot be ruled out with reasonable certainty. On the other hand, the incidence of malignant tumors subject glioma in the population is very high leave, it is around 6-9 cases per 100,000 inhabitants and assuming an increase in risk of 40% (?) the incidence would continue to be leave.

This news should not generate social alarm. Coffee, a carcinogenic agent classified in the same group as electromagnetic fields, is also associated with an increase in bladder cancer and people have not stopped drinking coffee.

The use of mobile should be done in a rational way and those people who due to their work must use it more intensively and want to avoid the proximity of electromagnetic radiation to the brain can increase the use of "hands-free" or headphones.