LETTER TO THE EDITOR
Editor’s note: this following represents the opinions of the authors and not necessarily those of the society as a whole. We invite alternate perspectives to be published in future issues.
We read the President’s message in the September/October issue of the Newsletter with interest. We fully agree that research designs should be built on a foundation of specific interaction mechanisms. This approach is critical for the hypothesis-driven research that can make solid advances in bioelectromagnetics. However, we do not agree with Prof. Kuster that “bioelectromagnetic research has progressed very little.” In our view the past decades have identified productive directions for future research and where further research would most likely be a waste of time and money.
We have published two manuscripts focused on biophysical and biological mechanisms that can serve to summarize the state of RF bioeffects research.[1,2] Our desire was that these might be used as discussion points and a guide to where the bioelectromagnetics community might look to expand and continue research based on these general mechanistic conclusions applicable to the ELF and RF regions:
- Physiological and bio-molecular systems employ electric fields that (vary) in magnitude from 1 - 200 V/m for physiological steady-state fields to >109 V/m for chemical bonds.
In order to affect a physiological process that involves low-frequency fields, an exogenous field must be of the order of magnitude of the local field, which suggests that to be effective exogenous fields need to be at least approximately one tenth of the local field strength. That is, an extremely sensitive system might respond if the signal-to- noise voltage ratio is as low as -20 dB.
We found, so far, no mechanism that points to a testable hypothesis for non-thermal effects between a few tens of megahertz and a few hundreds of gigahertz.
We found, so far, no conclusive evidence from independently reproduced studies that biological responses occur for low-level non-thermal exposures in this same frequency range.
Magnetic field affects can occur by induction of electric fields following the above quantitative guidelines and in specialized circumstances where magnetic interactions exist at microscopic or molecular levels.
In agreement with Prof. Kuster’s mechanisms-based approach, we believe that experimental work should proceed from a sound hypothesis derived, for example, from 1 and above. We think it better to design research starting from conditions where we know how things work in order to expand from there into unknown areas on a firm scientific foundation. Therefore, we encourage the research community to design experiments starting with exposure conditions that give repeatable outcomes and work from there to determine the lowest effective levels for a given waveform. We believe that this process is scientifically sound and can result in the “highly sensitive experiments” that Prof. Kuster desires with efficiency and good credibility for the outcomes.
Sheppard AR, Swicord ML, and Balzano Q, Quantitative Evaluations Of Mechanisms Of Radiofrequency Interactions With Biological Molecules And Processes, Health Physics, 95 (4) 2008
- Swicord ML and Balzano Q, Has Electromagnetic Energy in the Band 0.1 to 100 GHz Useful Medical Application? A review of Mechanisms and Biological Database Offers Dim prospects, IEEE Transactions on Plasma Science, 36 (4) 2008