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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; however,
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 investigating the
effects of RF exposures characteristic of mobile phones have yielded
conflicting results. A few animal studies, however, have suggested that low
levels of RF could accelerate the development of cancer 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
animal 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 that showed increased tumor development used animals that
had already been treated with cancer-causing chemicals, and other studies
exposed the animals to the RF virtually continuously--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 neuroma. There was also no
association between mobile phone use and gliomas when all types of
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.
1.
When 20 types of glioma were considered 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
