| Aegis Note: | This methods used in this study are inconsistent with methods established by the World Health Organization. The number of cancer cases was higher than what was reported in previous studies conducted in Sweden, and there was no consideration for how often or how long people used their phones. |
Danish
Cellphone Study Shows No Cancer Link
Reuters
Journalist: Per Bech Thomsen
February 06, 2001
A pioneering Danish study of more than 400,000 mobile-phone users showed no increased cancer risk but failed to rule out other health hazards such as migraines, Denmark's National Cancer Institute said Tuesday.
"This first-ever nationwide cancer incidence study of cellular phone users does not support any link between the use of these phones and brain tumors and cancers of the brain or salivary gland or leukemia," concluded the report, published in the U.S. Journal of the National Cancer Institute.
But the study did not clear cellphones of other health risks, senior researcher Dr. Christoffer Johansen told Reuters.
"We have only addressed the cancer question," he said. "We cannot exclude that long exposure to mobile phones can cause ringing noises in the head, migraine, headaches and other symptoms of the central nervous system."
He said it was theoretically possible that diseases like Parkinson's and Alzheimer's, various types of dementia and nervous complaints might be associated with mobile phones, as well as skin diseases at points where the device comes into contact with users.
Johansen said such a big study could only be carried out in Scandinavia where a system of compulsory registration of citizens is in place and cancer registries dated back to World War II.
FIRST
SURVEY OF ITS KIND
"Our study is the first nationwide, population-based analysis of its kind.
It is important because the link-up of information from different
administrative systems could simply not be done in other countries,"
Johansen said.
Data on 420,095 users identified from Danish mobile phone operators' subscriber lists were linked to information from the Danish Cancer Registry via the central population register. The study covered all eligible mobile phone users in Denmark from 1982-1995.
"All in all, 3,391 cancers were observed in the sample which is remarkably close to those expected on the basis of incidence rates in the general population," Johansen said.
Concern about mobile phones stems from the fact that when used, they emit low levels of radio frequency (RF) energy or radiation, scientists say.
Although the Danish study said radiation at sufficiently high levels could cause heating of parts of the body, a typical mobile phone operates at a low power output level with an associated "very low rise in brain temperature."
"If it is assumed that tumor promotion occurs close to the site of exposure, this finding provides additional evidence against a link between cellphone use and brain cancer," Johansen said.
Other experts studying potential links between cellphone use and cancer have noted that it takes ionizing radiation -- the kind put out by microwave ovens and radioactive materials -- to make the changes in cells associated with cancer. Cellphones do not produce this type of radiation.
Johansen, who expects the study to play a key role in possible U.S. lawsuits from brain tumor victims against mobile phone companies, said the fact that all data were gathered before the link between cellphones and cancer became a public issue gave the study greater credibility.
"These cancer patients were unbiased as to what caused the tumor," he said.