In October 2011, the British Medical Journal published research that looked at over 350,000 mobile phone subscribers in Denmark. The study reported cell phone users were of no more risk of developing cancer than non-subscribers.
Also in October, The Iowa Source featured an article reviewing research on cell phones that concluded heavy cell phone use increases risk of brain cancer. Who to believe?
Other scientists pointed out that the BMJ study was flawed. The limitations of this study are listed in the paper, which can be viewed online at bmj.com.
First of all, the BMJ study compared incidence of cancer for individuals with and without personal cell phone subscriptions. Corporate cell phone subscriptions were not included. Thus, individuals with corporate subscriptions, likely to be the heaviest users, would have been misclassified as non-subscribers.
Also, the researchers did not keep track of the amount of time people used their cell phones, only whether they owned a cell phone. The study would not have been able to determine if heavy cell phone use resulted in increased cancer because the study did not separate out heavy cell phone users from light cell phone users.
A third problem with the study is that subscription information was only available up to 1995, while the study extended up to 2007. Therefore, the researchers wrongly classified individuals who started using a mobile phone after 1996 as non-users. According to estimates, this mistake misclassified 86 percent of the Danish population who began using cell phones since 1996.
Denis Henshaw, Ph.D., Professor Emeritus of Human Radiation Effects at Bristol University, stated: “I consider the claims in the study to be worthless. This seriously flawed study misleads the public and decision makers about the safety of mobile phone use.” According to Devra Davis, Ph.D., M..PH., cancer epidemiologist and president of Environmental Health Trust, “From the way it was set up originally, this deeply flawed study was designed to fail to find an increased risk of brain tumors tied [to] cell phone use.”
When researchers at the Medical University of Vienna reanalyzed the same cancer data, without making the same mistakes, they found significantly increased risk for brain tumors in cell phone subscribers. These findings support previous research associating heavy cell phone use with brain cancer.
Reference: Cell Phones and Brain Tumors
Also see Richard Wolfson’s website