This is Gwen Outen with the VOA Special English Health Report.
A Swedish study suggests that people who use cellular phones for at least ten years might be at greater risk for developing a rare, non-cancerous tumor. These tumors are called acoustic neuromas. They grow on the nerve that leads from the inner ear to the brain. The risk was higher on the side of the head where the phone was usually held.
Acoustic neuromas affect fewer than one in one hundred thousand people a year. They grow slowly and can take several years to be discovered. The tumor pushes on the surface of the brain, but does not grow into the brain itself.
Researchers at the Karolinska Institute in Stockholm, Sweden led the study. It was published in the International Journal of Epidemiology.
The study involved seven hundred fifty Swedes. About one hundred fifty of them had acoustic neuromas. About six hundred other people did not. Researchers asked all of the people about their cell phone use.
The researchers found that those people who had used cell phones for at least ten years had almost two times the risk of developing acoustic neuromas. In addition, the tumor risk was almost four times higher on the side of the head where the phone was usually held.
There was no increased risk for those who had used cell phones for fewer than ten years. At the time the study was done, only analog phones had been in use for ten years.
Almost all early analog cell phones released more electromagnetic radiation than the digital phones now being sold. But researchers say they cannot be sure if the results are just linked to the use of analog phones. They say further study is needed.
Several earlier experiments have shown radiation from cellular phones can affect brain cells in a laboratory. But studies on people have found no evidence that the phones present a health risk. However, experts say children should avoid using the phones for long periods because their brains are still developing.
The study is part of a wider research program known as the Interphone study. The World Health Organization's cancer research institute organized the research. It is trying to find out if electromagnetic radiation from cell phones damages health.
Final results of the study are expected to be released early next year.
This VOA Special English Health Report was written by Cynthia Kirk. This is Gwen Outen.