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03/08/1995 08:00:00

Article Questions Validity of Research on Biological Effects of Electromagnetic Fields

PASADENA—Hundreds of scientific studies on the biological effects of electromagnetic fields may be invalid, researchers suggest in a letter to be published in the March 9 issue of the journal Nature. Controls have been inadequate to prevent contamination by magnetic particles in most lab studies done in this field, which includes millions of dollars of federally funded research.

The effects of magnetic contamination could explain some of the cellular changes that had been attributed to electromagnetic exposure, according to scientists at Oregon State University and the California Institute of Technology. The findings of their research do not mean such electromagnetic fields, or EMFs, are either safe or unsafe, the scientists say, and the research also has little relevance to human epidemiological studies on the effects of EMFs.

But it does indicate that lab research—about half of a five-year, $65 million federal program on the possible biological effects of EMFs—may be of questionable scientific value, said Michael Nesson, a research associate in the Oregon State University Department of Biochemistry and Biophysics.

"We're waving a red flag about what may be causing any supposed biological effects from these electromagnetic fields," Nesson said. "It is important, because our studies question the usefulness of many or most of the published laboratory research on the biological impact of EMFs."

Low-level electromagnetic fields, such as those caused by overhead power lines, household appliances, cellular telephones, and other aspects of industrialized culture, have undergone intense scrutiny in recent years. There is concern they may cause various health problems, including cancer. The jury is still very much out, Nesson said, on whether or not any of these serious concerns will prove to have a scientific basis. It's been hard to replicate the results of many experiments done in this area, and there's been considerable argument among scientists about what mechanism could have a biological or health impact.

"Because the field strength of these EMFs is so very low, it's been difficult to determine a biological impact with any certainty," Nesson said. However, some laboratory or "in vitro" tissue culture studies of EMFs have purported to find changes in cellular calcium ion release and uptake, alteration of cell division rates, and impacts on levels of messenger RNA.

Years of research on biologically produced magnetite by Nesson and his colleagues at Caltech, Associate Research Engineer Atsuko K. Kobayashi and Professor of Geobiology Joseph L. Kirschvink, have recently led the scientists to conclude that cellular EMF-exposure studies are all flawed by the lack of control for magnetic contamination. And it's now clear that ferromagnetic particles are present not only in dust in the air, but are also adsorbed onto the surfaces of laboratory equipment, present within glass and plastics, and even found in reagent-grade lab chemicals and water. Only with sophisticated "clean room" lab techniques can they be avoided.

Magnetite, the magnetic form of iron oxide, is quite common in the environment and was first known as the "lodestone" that formed the basis of the earliest compasses used by navigators. Magnetite absorbs energy from electromagnetic fields at both power-line and microwave frequencies.

"The presence of magnetite contamination in laboratory studies, which is extremely difficult to avoid, can negate the validity of these experiments," Nesson said. The magnetite particles could be adsorbed on cell surfaces or ingested by cells, transfer mechanical energy to mechanically activated ion channels, and thereby alter ion concentrations in the cell sufficiently to produce the observed biological effects, the scientists said in their letter to Nature.

The magnetic contaminant particles can be distinguished from biogenic, or biologically produced, magnetite, which has been found in trace amounts in human brain tissues, as well as in other organisms. The biogenic magnetite may provide a mechanism by which EMFs could bring about deleterious biological effects, as has been noted in some of the epidemiological studies. Continuing research will explore how these low levels of biogenic magnetite may function in tissues, Nesson said, and whether or not they play a role in producing biological impacts from exposure to electromagnetic fields.

Written by John Avery