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Using a cellular phone does not increase a person’s risk of cancer, according to a broad study released on Tuesday involving more than 400,000 Danish cellular telephone users.
A team of researchers used data on the entire population of Denmark to determine that neither short-term nor long-term use of cellular phones, also called mobile phones, was linked to a greater risk of tumors of the brain and nervous system, salivary gland (唾腺) or eyes, leukemia(白血病) or cancer overall.
"I think the results of this study are quite reassuring," Joachim Schuz of the Danish Institute of Cancer Epidemiology in Copenhagen, the lead researcher, said in an interview by cellular phone from Denmark.
The study, one of the most comprehensive to date, represented the latest evidence endorsing the safety of cell phones. The data available to the researchers allowed them to look at a large number of cell phone users and assess potential risks many years after they first used them.
The phones emit electromagnetic fields that can penetrate into the brain, and some scientists have sought to determine if this could cause cancer or other health problems.
Schuz’s team studied data on 420,095 Danish cell phone users (357,553 men and 62,542 women) who first subscribed for mobile service between 1982 and 1995 and were followed through 2002--meaning some were tracked for two decades. The researchers then compared their cancer incidence to the rest of Denmark’s population. A total of 14,249 cancer cases were seen among the cellular telephone users, a number that was lower than would be expected for that population, according to the study appearing in the Journal of the National Cancer Institute.
"We were not able to identify any increased risks of any cancers that could be related to the use of the cellular phones," John Boice, a cancer epidemiologist(流行病 学家) at Vanderbilt University who worked on the research, said in an interview. Boice said the type of radiation involved in cell phones is not known to damage cells or DNA. "So there’s no biological mechanism that would suggest that even this type of exposure could cause cancer or DNA damage," Boice said.
The researchers acknowledged some limitations in their work. Schuz said they could not differentiate between people who used the phones frequently and those who did so sparingly, meeting the researchers could not the out the possibility that some type of increased risk exists among heavy users.
"There is, in fact, a hazard from the use of a cellular phone that we have to all be concerned about," added Boice, but it is not cancer-related. "And that’s using a phone when we’re driving an automobile," leaving a driver distracted and causing accidents.
Some scientists want to make sure if cell phone use could cause any health problem as