Does exposure to smartphones cause cancer or tumors

Two studies, two results

WASHINGTON. Can Cell Phones Cause Cancer? Scientists have been looking for clarity for years.

A new study from the USA now shows signs of a slightly increased cancer risk in animal experiments. A large long-term epidemiological study from Australia, on the other hand, found no evidence of increased cancer rates in the population at almost the same time. The discussion about the potential dangers posed by microwave radiation from cell phones will therefore continue with passion - and with different research results.

Cell phone critics are listening

The study commissioned by the US government, costing 25 million US dollars (22.4 million euros), makes cell phone critics sit up and take notice again: For several years, researchers from the National Toxicology Program (NTP) have had more than 2,500 rats and mice irradiated with microwaves of the two common transmission technologies, GSM and CDMA. Ten minutes of irradiation, a ten-minute break - this was the rhythm at which the rats were exposed to 900 megahertz frequencies for nine hours per day for two years, the mice to 1900 megahertz. The rats were irradiated in three different strengths.

The result - which is still provisional because of the outstanding values ​​for the mice - in male irradiated rats, some gliomas and schwannomas developed on the heart. For the team led by Michael Wyde, National Institute of Environmental Health Sciences, Research Triangle Park (RTP) in North Carolina, this is "likely the result of whole-body exposure to GSM or CDMA-modulated radio frequencies".

Of the 90 irradiated male rats in each of the six test groups, up to three animals developed gliomas and up to six schwannomas. The 90 control animals showed none of these changes (bioRxiv 2016; online May 26).

In contrast, female rats did not develop statistically significantly more tumors. On average, the irradiated animals even lived longer than those of the control groups, and animal experiments could not be transferred one-to-one to humans, other scientists promptly noted critically in accompanying articles.

"Possibly Carcinogenic"

However, the tumors corresponded exactly to those that had previously been associated with cell phone radiation in several epidemiological studies. And in 2011 these were key factors for the WHO to classify cell phone radiation as "possibly carcinogenic". However, certain types of pickled vegetables and coffee also fall into this category.

Almost at the same time as the large animal study, Australian scientists presented the results of a 30-year long-term study. "We did not find an increase in the incidence of brain tumors that would have corresponded to the steep rise in cell phone use," report Simon Chapman, School of Public Health, University of Sydney, and colleagues in the journal Cancer Epidemiology (2016, online 4. May).

The scientists used Australia's mandatory cancer registry, for which they sifted through the brain tumor diagnoses of 19,800 men and 14,200 women between the ages of 20 and 84 between 1982 and 2012. The first cell phones were used in Australia in 1987, and 94 percent of the population called them in 2014.

Just better diagnostics?

Based on previous studies, the scientists actually expected a significant increase in cancer cases. But this did not happen. The researchers explain a slight increase in cancer diagnoses among men during this period with better diagnostic methods.

However, this study does not go unchallenged either.

Biotechnology expert Professor Dariusz Leszczynski from the University of Helsinki, who advised the WHO on its decision in 2011, considers the underlying latency period of ten years for the development of a tumor to be too short. "In addition, the misleading claim of 29 years of cell phone use should be replaced by a maximum of 15 years when cell phones were really widespread," he criticizes on his blog.(dpa)