en; VAR issue date: 040413
How much evidence is there that hand- held mobile phones might be harmful?
Briefly, there is not enough evidence to know for sure, either way; how- ever, research efforts are on-going. The existing scientific evidence is conflicting and many of the studies that have been done to date have suffered from flaws in their research methods. Animal experiments inves- tigating the effects of RF exposures characteristic of mobile phones have yielded conflicting results. A few ani- mal studies, however, have sug- gested that low levels of RF could accelerate the development of can- cer in laboratory animals. In one study, mice genetically altered to be predisposed to developing one type of cancer developed more than twice as many such cancers when they were exposed to RF energy compared to controls. There is much uncertainty among scientists about whether results obtained from ani- mal studies apply to the use of mobile phones. First, it is uncertain how to apply the results obtained in rats and mice to humans. Second, many of the studies showed increased tumor development used animals that had already been treated with cancer-causing chemi- cals, and other studies exposed the animals to the RF virtually continu- ously – up to 22 hours per day.
For the past five years in the United States, the mobile phone industry has supported research into the
safety of mobile phones. This research has resulted in two findings in particular that merit additional study:
1.In a hospital-based, case-control study, researchers looked for an association between mobile phone use and either glioma (a type of brain cancer) or acoustic neuroma (a benign tumor of the nerve sheath). No statistically significant association was found between mobile phone use and acoustic neu- roma. There was also no association between mobile phone use and glio- mas when all types of gliomas were considered together. It should be noted that the average length of mobile phone exposure in this study was less than three years.
When 20 types of glioma were con- sidered separately, however, an association was found between mobile phone use and one rare type of glioma, neuroepithelliomatous tumors. It is possible with multiple comparisons of the same sample that this association occurred by chance. Moreover, the risk did not increase with how often the mobile phone was used, or the length of the calls. In fact, the risk actually decreased with cumulative hours of mobile phone use. Most cancer caus- ing agents increase risk with increased exposure. An ongoing study of brain cancers by the
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