Motorola C331 - Manual (Page 152)

152
Additional Health and Safety
Information
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 cumulative hours of
mobile phone use. Most cancer causing agents increase
risk with increased exposure. An ongoing study of brain