EMF Research Activities Completed Under The Energy Policy Act of 1992 (1995) / Chapter Skim
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TECHNICAL PERSPECTIVES
TECHNICAL PERSPECTIVES
Pages 18-27
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From page 18... ...
The investigations have included characterization of the physical aspects of EMF exposure and measurements of the response of biologic systems, so research in this field requires strong multidisciplinary teams to properly record and control the full range of experimental variables and to reliably interpret the results. Research efforts must combine the talents of electrical engineers and physicists to describe the characteristics of exposure, cellular and molecular biologists and biochemists to explore the mechanisms of interactions at the fundamental level, physiologists and toxicologists to evaluate effects in intact functioning animals, and epidemiologists and physicians to interpret observed effects in the context of human health.
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From page 19... ...
The realization of the importance of this function early in the history of ELF-EMF effects research is a credit to the field arid, with the exception of a few studies, has helped to produce a literature in which exposure conditions are appropriate and well defined. Recently, some have criticized past research as having insufficiently characterized exposure conditions because characteristics and attributes of EMF not suspected as being important were not filly investigated: transient components, intermittence, the static geomagnetic fields strength and orientation, for example.
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From page 20... ...
field strength. Surprisingly, the increased sophistication of magnetic field exposure assessment in recent epidemiology studies has not significantly improved the correlation between estimated total exposure and the incidence of disease, even though the assessed exposures correlate much more favorably with contemporary exposures measured with a recording device worn on the body.
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From page 21... ...
Models invoking quantum mechanical resonances during concurrent exposure to specific alternating current and static magnetic field conditions, or response to spatial and temporal coherency of the field, have received some limited experimental support. Discrepancies between model predictions and experiments that use average rms field strength as the independent variable also have stimulated questions about whether there are other attributes of field exposure, such as transients, that might give rise to induced fields above the noise threshold.
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From page 22... ...
Second, the term "EMF" can be applied to field conditions that vary in several respectseven when limited to frequencies of 50 or 60 Hz. It has been suggested, for example, that transients, large excursions from the normal field strength that can occur on a fast time scale, are by nature more "biologically detectable" than are smooth-varying power frequency sinusoidal electric or magnetic fields.
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From page 23... ...
Even though it seems unlikely that the three goals of the toxicologic approach are immediately achievable for the case of EMF exposure, in vitro and in viva studies have an intrinsic value; the determination of biologic sensitivity to EMS exposure should be considered as an important component of toxicology, independent of the direct application to risk assessment. An additional factor that must be considered in the evaluation of the role of EM exposure on human health effects is the regular appearance of publications suggesting new biologic effects of Ed, particularly in combination with other agents known to be detrimental to health, such as chemical mutagens.
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From page 24... ...
These show both positive and negative effects for EMF, again for a fairly wide spectrum of EMF exposures and mostly at field strengths significantly exceeding those in the normal environment. The studies have examined several effects, including the foJ~ow~ng: · Membrane effects with emphasis on biophysical mechanisms of charge distribution and inhibition of membrane Unctions, such as the operation of ion channels and of transmembrane receptors.
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From page 25... ...
Research and Public Information Dissemination (RAPID) program has had the following goals: · Confirm or refute reports of EMF exposure elevating or decreasing several end points in cultured cells.
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From page 26... ...
For some end points-including cancer, developmental toxicity, and neurobehavioral effects-this is the level at which end points must be assayed, quantified as to the magnitude of effect, and characterized mechanistically. Although in vitro studies can identify the toxic properties of agents and can be useful in studying mechanisms, observations of toxic effects in exposed animals remain the major tool to characterize potential toxicity for any given agent, free of the confounding variables intrinsic to epidemiologic studies of human populations.
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From page 27... ...
· Chronic toxic effects, such as cancer, must be interpreted in animal studies through a knowledge of the dose-response relationship for the toxic eject of concern in the species of animal used. This knowledge not only assists interpretation of effects induced by high doses in a limited number of animals, but also places this information qualitatively and quantitatively within a structure of results from an extremely large number of toxic agents.
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