姜紅偉

A Swedish study suggests that people who use cell phones for at least ten years might be at greater risk for developing a rare tumor. These tumors are not cancer. They 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 100，000 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.

The study involved 750 people. About 150 of them had acoustic neuromas. About 600 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. Also， 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.

Earlier experiments have shown radiation from cell phones can affect brain cells in a laboratory. But studies on people found no evidence that the phones cause danger to health. However， experts say children should avoid using the phones for long periods because their brains are still developing.