By MATT MOORE
STOCKHOLM, Sweden (AP) - A new Swedish study
suggests that people who use a mobile phone for at least 10 years might increase
their risk of developing a rare benign tumor along a nerve on the side of the
head where they hold the phone.
In an interview with The Associated Press on
Thursday, one of the researchers behind the preliminary study, Anders Ahlbom,
said the results were surprising and need to be confirmed by more research.
Over the last few years, several studies have investigated whether the use of cellular phones is linked with an increased risk of brain tumors, but experts say the right studies have yet to be done.
Although experiments have shown that radiation from mobile phones can affect brain cells in a lab, it is unclear whether that translates into a threat in real life. More relevant studies on people have found no evidence that the phones pose a health risk.
However, experts have said that because children's brains are still developing, it may not be a good idea for youngsters to use the phones for long periods of time until more is known about the health effects.
The three-year study by Ahlbom and Maria Feychting, both professors at the Karolinska Institutet in Stockholm, focused on 750 Swedes who had used mobile phones for at least 10 years.
``We are eagerly awaiting the results of other studies,'' he said of the study, published in the International Journal of Epidemiology.
Using 150 patients who were already diagnosed with acoustic neuroma, a benign tumor on the auditory nerve that takes several years to grow before being diagnosed, and 600 who did not have it, researchers questioned them about their mobile phone use.
All 750 subjects had been using their mobile phones for at least 10 years, nearly all of them the early analog models, as opposed to the digital models currently on the market.
``At the time the study was conducted only analog mobile phones had been in use for more than 10 years and therefore we cannot determine if the results are confined to use of analog phones or if the results would be similar also after long-term use of digital (GSM) phones,'' the report said. Nearly all the mobile phones sold by Nokia, Motorola, Samsung and Sony Ericsson, among others, are digital, not analog.
The risk of developing the tumor was almost double for those who started to use phones before their diagnosis.
``When the side of the head on which the phone was usually held was taken into consideration, we found that the risk of acoustic neuroma was almost four times higher on the same side as the phone was held,'' Ahlbom and Feychting said.
Retrospective questionnaires are not considered to be the most robust method of determining the link between a behavior and disease. Many times, links that emerge from such studies turn out not to be true when the connection is studied more rigorously.
Normally, the tumor, which can affect hearing, occurs in less than one adult per 100,000 people annually. The tumor pushes on the surface of the brain, but doesn't grow into the brain itself, according to the Atlanta, Georgia-based Acoustin Neuroma Association.
``They were surprising, they were stronger than I had expected,'' Ahlbom told the AP. ``To be quite honest, I hadn't expected anything. We don't know what has caused it.''
But, the study, which was funded by the European Union and is part of the wider Interphone study coordinated by the International Agency for Research on Cancer, needs outside confirmation.
It's also revived concerns over whether using mobile phones is harmful to a person's health.
Previous studies, including one by Finnish scientists in 2002, found that the electromagnetic radiation emitted by phones can affect brain tissue, but others have said that's not the case, which was the finding of a Danish group participating in the same Interphone study.
The wireless industry has always maintained that there is no link between mobile phones and cancer.
On Wednesday, the Wireless Association in Washington, D.C., a trade group representing American mobile phone manufacturers, urged more research.
``The wireless industry agrees that more research is needed in this area to provide definitive answers to any questions that might still exist,'' it said in a statement. ``Numerous independent scientific bodies have conducted research on possible health effects from using wireless phones and it is widely accepted that no conclusive link can be made.''
Ahlbom conceded that more research was needed, and added that the study was not an excuse to avoid using mobile phones.
``You could say also, of course, if that someone is concerned about these results the easy way to avoid any risk is to use a handsfree set,'' he said.
10/14/04 12:57
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