October 29, 2001 TOKYO (Asahi News Service) - Electromagnetic fields like those produced by power lines may interfere with a cancer-suppressing hormone, according to Japanese researchers whose work has strengthened the findings of their counterparts overseas.
The announcement by scientists at the National Institute for Environmental Studies in Tsukuba, follows years of concern about the possible health effects posed by high-voltage transmission lines and home appliances.
Masami Ishido and Michinori Kabuto showed in their research at the institute that electromagnetic fields disrupted the functioning of the hormone melatonin in individual cells. Further research will be required, however, to establish what effect electromagnetism has on humans.
Ishido and Kabuto presented their findings at a conference of the Japanese Biochemical Society held in Kyoto, adding support to similar work done in other countries. Four such studies have reportedly been conducted elsewhere. Research has shown that melatonin, which regulates the body's sleep cycles, can if taken as a diet supplement hasten sleep and ease jet lag without the side effects associated with conventional medication.
Scientists have accepted since 1987 that the substance suppresses the multiplication of cancer cells.
Ishido and Kabuto demonstrated through their work that adding melatonin to a type of breast cancer cell easily affected by magnetism suppressed the growth of the cell.
They exposed two batches of the cell to two different levels of electromagnetic field: one at between 1.2 and 4 microtesla-the level to which most humans are exposed in their daily lives-and the other at about 100 microtesla. In both cases, the ability of melatonin to suppress the growth of the cancer cells was found to have declined. In some cells with smaller concentrations of melatonin, the suppressive effect was entirely absent.
The researchers determined that electromagnetism can disrupt the three chemical elements with which the melatonin interacts when suppressing the growth of cancer cells.
Although the research was on the level of single cells, the methods used could be adapted for evaluating the effects of electromagnetic fields on the human body.
Junji Miyakoshi, an associate professor at Kyoto University involved in the World Health Organization's International Agency for Research on Cancer, said the importance of the research was in replicating the result of an experiment conducted in the West and in demonstrating the mechanism by which the suppression function is disrupted.
Copyright 2001 Asahi News Service. All rights reserved.
