Ericsson T28z User Manual page 118

because a person's RF exposure decreases rapidly with distance from the
source. The safety of so-called "cordless phones," which have a base unit
connected to the telephone wiring in a house and which operate at far lower
power levels and frequencies, has not been questioned.
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.
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
Guidelines for Safe and Efficient Use 117