Group Rebuts Latest Cell Phone-Brain Tumor FindingsOct 24, 2011 | Parker Waichman LLP
A group of experts is not impressed with a recent study that appears to give cell phone radiation a clean bill of health when it comes to brain tumors. According to a rebuttal posted on ElectromagneticHealth.org, a U.S.-based health education and advocacy group, the new study is “unsurprising, biased and misleading."
The study, entitled “Use of mobile phones and risk of brain tumors: update of Danish cohort study,” was published online in the British Medical Journal. Its authors claim their findings show no link between long-term use of cell phones and tumors of the brain or central nervous system among 358,403 mostly male cell phone subscribers over the age of 30 during the period 1990-2007. The report is a follow-up to an earlier Danish analysis of the same group that also reported no cell phone-cancer link when the average use of cell phones was less than a decade.
Technical experts from the U.K., U.S., Austria, Sweden and Australia, all of whom who have provided critical reviews on the study to Environmental Health Trust, claim the it is seriously flawed, and was designed to fail to find any link between cell phone radiation and cancer.
“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 with cell phone use. In order for any study of a relatively rare disease like brain tumors to find a change in risk, millions must be followed for decades," Devra Davis, PhD, MPH, cancer epidemiologist and President of Environmental Health Trust, commented. "By extending an earlier analysis on the same group of cell phone users this new report provides unsurprising, biased and misleading conclusions. It uses no direct information on cell phone use, fails to consider recent and rapidly changing nature of and exposure to microwave radiation from cell phones, cordless phones and other growing sources, and excludes those who would have been the heaviest users—namely more than 300,000 business people in the 1990s who are known to have used phones four times as much as those in this study."
Among other things, the rebuttal raises questions about the individuals chosen to represent the study's control group. According to a report from MedScape, the Danish researchers compared the rates of brain tumors that occurred from 1990 to 2007 in those who began using cell phones after 1987 with the rates in those who were nonsubscribers when the study started. "This understates risk, because most of those who began as 'nonsubscribers' to cell phone service (i.e., the 'controls' at the time the cohort was collected) became cell phone users later on, and accumulated almost as many years (on average per person) as the 'exposed' subscribers. Hence, the comparison to the population not contained in the subscriber sample is a comparison between 2 exposed groups," the group writes. This weakness, they assert, "would dilute any association between [cell-]phone use and cancer risk, and this is important for a negative study like the current one."
The rebuttal also asserts that while the Danish study is being promoted in the media as having not found a link between radiation and cancer, it did, in fact find "a significant increased risk of a very rare form of glioma of the cerebral ventricle based on 8 cases." "Ina study of relatively rare diseases, such as brain tumors, the failure to obtain statistical significance should not be confused with a lack of public health importance." the rebuttal states.