Cell Phone Safety Study Suggests No Risk of Cancer

Incidence ratios for all cancers for mobile phone subscribers versus ratios for the general population in Denmark. Adapted from "Use of mobile phones and risk of brain tumours: update of Danish cohort study", table 1.

A major study in Denmark found no increased risks of cancer among cell phone users, suggesting that there is little evidence that exposure to cell phones is related to tumors of the central nervous system. The study, however, is unlikely to settle the ongoing public policy debate over the safety of electromagnetic emissions from wireless devices.

The nationwide Danish cohort study examined the health records of all citizens aged 30 and over, subdivided into cell phone subscribers and non-subscribers, between 1990-2007. The risk of tumors for cell phone users, even those with the longest exposure - over 13 years of mobile phone use - was nearly identical to that of the overall population. In addition, the study concluded that there was no correlation between cell phone use and tumor location - that is, cell phone users were not any more likely to get tumors in regions of the brain closest to where the handset is usually held to the head.

The study, published in the British Medical Journal, has drawn fire from some scientists for its methodology and the sample size. As wireless devices such as cell phones become more ubiquitous, so too has public concern over the possible health effects of the radiation they emit. This debate has been especially vocal in California, where opposition to the installation of wireless smart meters by Pacific Gas & Electric prompted a study on their safety by the California Council on Science and Technology. Moreover, San Francisco passed a law due to go into effect on Tuesday requiring warning labels on cell phones, warning of health risks from prolonged exposure to the devices. However, implementation has been delayed due to a lawsuit filed by a wireless industry group.

Conflicting messages from experts are likely to perpetuate confusion in the public. The official position of the Federal Communications Commission is that there is no scientific evidence to date that wireless phone usage can lead to cancer. However, although citing no new evidence, the World Health Organization issued a warning in June that cell phone electromagnetic fields are "possibly carcinogenic to humans."

Despite the public ambivalence about the issue, many in the scientific community have welcomed the new study and its implications for the safety of wireless devices overall.

"This is encouraging news about cell phones because smart meters use similar technology," said CCST Senior Fellow Jane Long, principal associate director at large at the Lawrence Livermore National Laboratory. "Smart meters are expected to have a much lower impact than cell phones, and smart meters are a critically important part of reinventing the energy system in a world that has to be concerned about climate change."