The
following is the official report summary of a study conducted for the Electric
Power Research Institute (EPRI). The
summary details how the researchers found that cells subjected to low-level EMF
radiation showed the same response as did the same cells subjected to elevated
temperatures. This represents one “smoking
gun” linking EMF and a host of diseases. As shown below, the EPRI
concluded, “To confirm and extend this research, a careful, independent
replication effort will be required.” Nevertheless,
it never funded further research on this subject, nor has it subsequently
provided funding to the leaders of this research effort.
Studies on the Mechanism of
Electromagnetic Field
Interactions
With Cells:
II. Electric and Magnetic Signal
Transduction in a Membrane Protein
TR-1 08947
Final Report, October 1997
Prepared by
Columbia University
Department of Physiology and Cellular Biophysics
630 West 168th Street
New York, New York 10032
Principal Investigator
M. Blank
Prepared for
Electric Power Research
Institute
3412 Hillview Avenue
Palo Alto, California 94304
EPRI Project Manager
C. N. Rafferty
Environment Group
for
Strategic Research &Development
REPORT SUMMARY
Improvements in basic knowledge of how electric and magnetic fields (EMF) affect cells may help resolve uncertainty about EMF exposure and human health. This report describes studies of EMF on two in vitro biological systems. Effects are reported for a large range of frequencies and field levels, including magnetic field levels of less than 1 μT (10 mG) at 60 Hz. To explain these effects, the study proposes a biophysical model involving the interaction of magnetic fields with moving charges in enzymes and DNA.
The two biological systems investigated in this study are found in all animals, including humans, and are necessary for normal physiological function. One system involves a protective property of cells, called the “stress response,” in which special proteins are synthesized in response to potentially damaging external environmental chemical or physical agents such as elevated temperature. The second system involves modulation of the activity of a membrane ion transport enzyme—sodium, potassium ATPase (Na,K-ATPase)—an enzyme which plays a role in cellular signal transduction. This study addresses these two biological systems to provide insight into aspects of both the cell biology and cell biophysics of EMF exposure.
To characterize the responses of two in vitro biological systems to EMF exposure for a broad range of field conditions and to develop a biophysical model of interaction.
Investigators studied the stress response using salivary glands from the larva of a fly called Sciara. Intact glands were either kept as controls at 20º C, exposed to elevated temperature (usually 37º C), or exposed to extremely low frequency (ELF) magnetic fields from 0.8 μT (8 mG) to 800 μT (8 C) using a Helmholtz coil apparatus. To characterize treatment responses, they measured proteins using 2D gel electrophoresis of homogenized glands. This technique provides information about the molecular weight, the isoelectric point, and quantity of proteins. Investigators studied the activity of a membrane bound Na,K-ATPase in vesicles prepared from rabbit kidneys. They measured ATPase activity by spectrophotometric determination of the amount of inorganic phosphate formed 40 mm. from the start of the enzyme reaction. They exposed samples for 15 mm. to either ELF electric fields by direct application of electrodes or ELF magnetic fields using a Helmholtz coil apparatus. Finally, they tested the effects of electric fields for levels of 2.4 mV/m to 2.4 V/m and magnetic fields for levels of 0.2 μT (2 mG) to 1 ml (10 G).
In examining the stress response, similar effects were observed, both in type and magnitude, for temperature elevation (thermal shock) and for exposure to magnetic fields. For both thermal shock and magnetic field exposure, the characteristic heat shock protein, hsp70, was detected. There were no significant differences between experiments that exposed cells to the two stimuli simultaneously or sequentially. These experiments suggest that the same cellular stress response system is stimulated by magnetic fields as for temperature. Effects were reported for fields as low at 0.8 μT (8 mG).
Investigators reported that the activity of the Na,K-ATPase enzyme was changed by exposure to either electric or magnetic fields. Under conditions of near optimal enzyme activity, electric fields inhibit this activity by about 20%, whereas magnetic fields increase this activity by about 10%. However, when the initial (basal) activity of the enzyme is greatly reduced, then both electric and magnetic fields increase activity by a factor of up to 1.8 of basal levels. The investigation concluded that the initial state of enzyme activity appears to determine the nature of the field response. Magnetic field effects were reported for levels as low as 0.2 μT (2 mG).
Based in part on these experiments, the study proposes a biophysical model in which external fields interact with moving charges in either the enzyme (Na,K-ATPase) or in DNA (the stress response). The study also discusses the potential significance of these findings to human health, noting that both beneficial and adverse effects are possible.
This study reports the existence of biological effects in the two in vitro systems investigated over a wide range of exposure conditions. The investigators propose a biophysical model to explain these observations. One notable aspect of this research is the observation of effects at very low magnetic field levels (<1.0 μT [10 mG]. To confirm and extend this research, a careful, independent replication effort will be required. Other investigators have raised the question of endogenous signal levels and thermal noise in membranes as providing a fundamental limit to the detection of external fields by biological systems. The biophysical model developed in this study should be further considered in the context of such theoretical factors. As is generally true for in vitro effects, it is not possible to predict whether the effects reported in this study have any downstream consequences on human health. Related EPRI work includes a review of contemporary biophysical mechanisms of EMF interaction (report TR-1 04800)
Electric and magnetic fields
Keywords
Magnetic fields
Electric fields
Biological effects
Biological models
Biochemistry
Health effects