Prolonged and heavy cell phone use did not increase the risk of brain tumors

European researchers conducted a large-scale prospective cohort study on a sample of 265 thousand people and concluded that the use of cell phones does not increase the risk of brain tumors - in particular, glioma, meningioma and acoustic neurinoma. The paper is reported in the journal Environment International.

The emergence of each new generation of cell phones has provoked heated debate over concerns about the possible carcinogenicity of the radiofrequency electromagnetic radiation they use. Although the available evidence argues against such a view, it often fails to capture the effects of long-term and high-intensity phone use, and is subject to various systematic errors due to design (mainly of the case-control type).

To overcome these limitations, the largest ongoing cohort study of the health effects of cell phones, COSMOS, was launched. Now its author Maria Feychting (Maria Feychting) from Karolinska University and colleagues from the UK, Denmark, Finland, France, the Netherlands, France and Sweden have used the data to analyze the possible association between phone use and the incidence of central nervous system tumors: glioma (malignant), meningioma (mostly benign) and acoustic neurinoma, aka vestibular schwannoma (benign). Almost 265,000 people aged 18 years and older from the listed countries (except France) were included from 2007 to 2012, with a median follow-up period of 7.12 years (total 1,836,479 person-years). They were free of brain neoplasms at the time of inclusion and had no history of brain neoplasms.

Participants were stratified by age, sex, and cell phone use (at inclusion, participants reported how many years of use, then information was obtained from service providers; cutoffs were made at the median and 75th percentile, for glioma also at the 90th percentile). Information on their health was obtained by prior consent from national health registries. Statistical processing of the data was performed using Cox regression models.

During the follow-up period, 149 cases of glioma, 89 cases of meningioma, and 29 cases of acoustic neurinoma were recorded among the participants. It was found that neither the total duration nor the intensity of cell phone use had a statistically significant effect on the risk of developing any of these tumors. At the same time, almost a third of the participants had used a cell phone for 15 years or more, and the number of regression-calibrated cumulative hours of use in the highest 10th percentile exceeded 1900.

Based on the findings, the authors of the paper concluded that cumulative level of cell phone use does not reliably affect the risk of glioma, meningioma, and acoustic neurinoma.

Earlier, Chinese researchers who analyzed data from the British Biobank found that talking on a cell phone for more than five minutes a week was associated with a seven percent increase in the incidence of arterial hypertension. And their Swiss colleagues found that heavier cell phone use correlated with lower sperm concentration and total sperm count in the ejaculate, but this work has some serious limitations.