Electromagnetic Waves Linked To Children's Brain Tumors
Kyodo News Service
June 7, 2003

Exposure to electromagnetic waves from high-voltage power lines and some electronic appliances could increase the risk of brain tumor among children who live close to the source of emission, according to a three-year government-sponsored study.

Ultralow frequency electromagnetic waves are produced primarily by high-voltage power grids, whose effects on human bodies have been studied by overseas researchers. The same type of electromagnetic waves is also released in tiny amounts from computers and other home appliances.

While the study in Japan -- initiated three years ago by the former Science and Technology Agency, now part of the education ministry -- has shown a link between brain tumor and exposure to electromagnetic waves, authors of the report caution that the finding is not conclusive due to a limited size of the samples available for the project.

The study, undertaken by the National Institute for Environmental Studies, Tokyo Women's Medical University and others, compared the level of electromagnetic waves in the bedrooms of 100 healthy children and 60 children suffering from brain tumor below age 15, examining each case over a one-week period.

The researchers then tabulated the data after adding factors such as the average level of electromagnetic waves in the entire house, the extent of use of electric appliances and the distance between a child's room and a high-voltage power line.

The results, posted on the education ministry Web site on Friday, show that children exposed to more than 0.3 microtesla of extralow frequency electromagnetic waves, or three times the normal level, are 10 times more likely to develop brain tumor.

The researchers found that the level of electromagnetic waves actually topped 0.3 microtesla in the rooms of five children with brain tumor and one healthy child, and the rooms of three of the children with brain tumor were located within 100 meters of a high-voltage power transmission line.

The researchers have also found that exposure to electromagnetic waves above 0.4 microtesla would double the risk of childhood leukemia. The final report released Friday says the risk of developing acute lymphoblastic leukemia is comparatively higher than the risk of acute myelogenous and other types of leukemia.

The electromagnetic waves emitted by high-voltage power lines are different from the electromagnetic waves that come from mobile phones and microwave ovens, where the frequency is much higher.