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(Database last updated on Mar 27, 2024)
| ID Number | 1215 | |
| Study Type | Engineering & Physics | |
| Model | Mechanistic studies to determine if EMF/RF fields can affect biological systems (e.g., molecular transport, chemical reaction rates, rectification, temperature perception, radical pairs, nerve cells). | |
| Details | Mechanistic study to determine whether applied RF electric fields to cells might hypothetically cause biological effects due to gradients at the cell membrane / extra cellular fluid interface with forces large enough to affect ionic motions with possible subsequent effects on cellular function. The authors used a 2-nm cell membrane model with water on either side, assuming the electric permittivity of the membrane differed from water creating a non-uniform field with a large gradient (within about 0.4 nm of the membrane boundary on each side) upon application of an external electric field. The authors developed a probability distribution for molecules as a function of distance from its initial position, and could model conditions where molecules were either attracted to / more likely to remain associated with, or conversely repelled from the membrane. For reference, with a 900 MHz mobile phone with an SAR of ~1 W/kg, they calculate the voltage across the membrane as less than 3 microV, producing an energy ~1,000 times smaller than the room-temperature thermal energy (kT) of 0.026 electron-volts, and that at this level of energy it might take ~31 years to observe an effect using their model. In a subsequent paper, the authors use differential equations to describe the combined action of DC and AC magnetic fields on thermal motion of ions in a biological macromolecule. The authors report that theoretically, under conditions where ion oscillations occur in the cellular interior and are well shielded from the external media, it is possible that the change in energy of ion thermal motion could be sufficient to alter the conformation state of the macromolecule. The authors suggest that these findings may explain many diverse reports in the literature of biological effects due to low level RF energy, or effects based upon frequency and amplitude windows, without participation of cyclotron or parametric resonances in these effects. In a related study, the authors solve differential equations for the combined action of DC and AC magnetic fields on thermal motion of ions in biological macromolecules and suggest a new set of resonant peaks for ion oscillations. They hypothesis that if the macromolecule interior can establish a well shielded state from the outside medium, the change in energy could be sufficient to alter the conformation state of the macromolecule and thus form the basis for previously reported non thermal biological effects, or effects that demonstrate frequency or amplitude windows. AUTHORS' ABSTRACT: Barnes and Greenebaum 2015 (IEEE #5837): It is proposed that radical concentrations can be modified by combinations of weak, steady and alternating magnetic fields that modify the population distribution of the nuclear and electronic spin state, the energy levels and the alignment of the magnetic moments of the components of the radical pairs. In low external magnetic fields, the electronic and nuclear angular momentum vectors are coupled by internal forces that outweigh the external fields interactions and are characterized in the Hamiltonian by the total quantum number F. Radical pairs form with their unpaired electrons in singlet (S) or triplet (T) states with respect to each other. At frequencies corresponding to the energy separation between the various states in the external magnetic fields, transitions can occur that change the populations of both electron and nuclear states. In addition, the coupling between the nuclei, nuclei and electrons, and Zeeman shifts in the electron and nuclear energy levels can lead to transitions with resonances spanning frequencies from a few Hertz into the megahertz region. For nuclear energy levels with narrow absorption line widths, this can lead to amplitude and frequency windows. Changes in the pair recombination rates can change radical concentrations and modify biological processes. The overall conclusion is that the application of magnetic fields at frequencies ranging from a few Hertz to microwaves at the absorption frequencies observed in electron and nuclear resonance spectroscopy for radicals can lead to changes in free radical concentrations and have the potential to lead to biologically significant changes. AUTHORS' ABSTRACT: Barnes and Greenebaum 2016 (IEEE #6352): Concerns have been raised about the possible biological effects of nonionizing radiation since at least the late 1950s with respect to radar, other radio, and microwave sources. More recent concerns have arisen about the potential effects of low-intensity fields, including lowfrequency fields from the electric power generating, transmission, and distribution system and the devices it energizes, as well as intermediate, radio-frequency (RF), and higher-frequency radiation from devices such as cell phones, broadcast antennas, Wi-Fi, security monitors, and so forth. These are concerns about the direct effects of radiation on humans or other organisms. They are distinct from the electromagnetic compatibility issues that concern interference by the fields from one device with the function of another, though human health can be indirectly affected by electromagnetic interference with the function of medical devices, including hospital equipment or pacemakers. AUTHORS' ABSTRACT: Barnes and Greenebaum 2018 (IEEE #7002): Radio frequency electromagnetic fields (RF) have been shown to modify the concentrations of the radical O2-, H2O2 and cancer cell growth rates at exposure levels below those that cause significant heating. Reactive oxygen species (ROS) are both signaling molecules and species that can do damage, depending on timing, location and concentrations. We briefly look at some mechanisms by which electromagnetic fields can modify the concentrations of ROS and some of the feedback and repair processes that lead to variable biological effects. Of particular interest are the role of radical pairs and their spins, which have received considerable attention recently, and the role of feedback in biological systems, to which less attention has been paid. |
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| Findings | Effects | |
| Status | Completed With Publication | |
| Principal Investigator | University of Colorado, Boulder, - zhadin@online.stack.net | |
| Funding Agency | Private/Instit., MMF | |
| Country | UNITED STATES | |
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