BEMS Journal Article Summaries

Editor’s note:  The Bioelectromagnetics Society recently implemented a “Best Paper” award.  While not directly connected with that award, we have invited all authors of recently published full research articles in the Bioelectromagnetics journal to provide a short summary of the background and context of the research documented in their articles so that Society members can from different disciples can better understand the reported work.  For copyright reasons, these summaries are different from the abstracts published in the journal.  In providing additional focus on the reported research, it is our hope that communication within the society is enhanced, providing a stronger basis for assessing and selecting the best paper(s) published each year.  These summaries are being printed in the order received by the newsletter office. 

Study of Narrow Band Millimeter-Wave Potential Interactions with Endoplasmic Reticulum Stress Sensor Genes

Bioelectromagnetics, Volume 30, Issue 5, pp. 365-373.

Authors:  Maxim Zhadobov, Ronan Sauleau, Christophe Nicolas Nicolaz, Yves Le Dréan

Nowadays, the saturation of the lower part of the microwave spectrum and need for higher data rate transmissions impose the use of broadband signals for communication purposes and the increase of operating frequencies up to the millimeter-wave frequency band (30-300 GHz). At millimeter waves, several sub-bands, including frequencies around 60, 120, and 190 GHz, are strongly attenuated in the atmosphere due to the resonant oxygen- and water-induced molecular absorptions. Atmospheric attenuation makes these frequency regions extremely attractive for secure short-range communications, decreasing thereby interferences between neighboring systems. In particular, the 57-64 GHz frequency range has been clearly identified by standardization committees (IEEE 802.15), and world-leading telecommunication companies consider it as extremely promising for high-data-rate communications particularly in indoor environments (WPAN, WiHD, wireless USB, wireless video, streaming data, etc.). Furthermore, the progress in millimeter-wave electronics has triggered a number of emerging applications for point-to-point and point-to-multipoint communications, intelligent transport systems, localization, imaging systems, etc. Simultaneously, public concerns about possible biological effects and related potential biological and health impacts have increased exponentially. From the scientific point of view, two facts suggest that millimeter waves around 60 GHz could interact with biological systems. First, these radiations were originally absent in our natural environmental electromagnetic spectrum. Second, these radiations have been used in several Eastern European countries for therapeutic purposes, providing as scientific evidence for such applications Fröhlich theory and results of some scientific / clinical studies.

In this context, a number of research groups in Europe, United States, and Asia have started to investigate different biological aspects of possible interactions, including in vitro studies at sub-cellular and cellular levels and in vivo studies on animals. Among them the contribution of the Institute of Electronics and Telecommunications of Rennes (IETR, www.ietr.org) and of the group of Cellular and Molecular Interactions (ICM, www.umr6026.univ-rennes1.fr), University of Rennes 1, France take a significant place, particularly regarding the identification of potential millimeter-wave-induced modifications at cellular and sub-cellular levels. One of the major challenges of these studies is to provide well-controlled and reproducible experimental protocols and dosimetry to ensure accurate experimental replication. This implies the implementation and adaptation of advanced numerical modeling approaches and the development of specific experimental techniques.

Most of the recently reported studies confirmed the absence of biological effects for power densities below the exposure limits for general public. However, the fundamental questions about the biological frequency-dependent power thresholds for the biological effects remain almost unexplored. Our joint IETR/ICM research team combines strong expertises in electromagnetics and cellular biology to address these important questions. Our recently published in Bioelectromagnetics Journal paper entitled "Study of narrow band millimeter-wave potential interactions with endoplasmic reticulum stress sensor genes" continues a series of studies aiming to provide a key scientific insight into the physical mechanisms and biological issues of bioelectromagnetic interactions at millimeter waves. This article reports the results of the potential effects on the endoplasmic reticulum stress sensor genes for a set of the discrete frequencies within the 59-61 GHz frequency sub-band. Our results suggest that the endoplasmic reticulum homeostasis is not altered by low-power millimeter waves at the considered frequencies. However, we cannot exclude that other exposure parameters, such as intensity, polarization, modulation, or exposure duration may have direct or synergistic impact on cells. Additional investigations are now in progress to acquire deeper knowledge on interactions between millimeter waves and biological systems. 

Effects of radio frequency magnetic fields on iron release from cage proteins 

Bioelectromagnetics, Volume 30, Issue 5, pp. 336-342.

Authors:  O. Céspedes and S. Ueno.

 

Cells, tissues and organs are diamagnetic complex biosystems that interact only weakly with magnetic fields. Therefore, the effect of radio frequency (RF) radiation in biology is commonly attributed to the heating in a tissue or solvent generated by the electric component of the field [Barnes, 2005]. Nevertheless, nanoscale, iron-rich bioelements, such as biogenic magnetite nanocrystals and some iron proteins, are superparamagnetic, and increase their internal energy when exposed to alternated magnetic fields.

 

The iron cage protein ferritin [Harrison et al., 1996], present in almost all organisms from bacteria to humans, is composed of a natural superparamagnetic ferrihydrite nanoparticle inside a roughly spherical proteic cage.  In our paper we hypothesize that this association between magnetic material and biomolecule allows for an effective energy transfer from the former to the later when an RF magnetic field is applied. We tested this novel mechanism of interaction by exposing horse spleen ferritin samples to magnetic fields with different frequencies and amplitudes, and then measuring the iron release rates from the proteins.

 

We found that ferritins previously exposed for several hours to magnetic fields of the order of 1 MHz and 30 mT released up to three times less iron that the control samples. The effect is dependent on the frequency-amplitude product of the magnetic field, as predicted by the superparamagnetic relaxation hypothesis. Given the essential role played by ferritin in iron chemistry, any functional unbalance induced by alternated magnetic fields has potentially a great relevance both in the study of radio/microwave field effects and biomedical engineering.

 

Barnes FS. 2005. Mechanisms for electric and magnetic fields effects on biological cells. IEEE. Trans. Magn. 41: 4219-4224.

Harrison PM, Arosio  P. 1996. Ferritins: Molecular properties, iron storage function and cellular regulation. Biochim. et Biophys. Acta 1275: 161-203.

 

No effects of UMTS exposure on the function of rat outer hair cells

Bioelectromagnetics, Volume 30, Issue 5, pp. 385-392.

 

Authors:  Paulo Galloni, Vanni Lopresto, Marta Parazzini, Rosanna Pinto, Marta Piscitelli, Paulo Ravazzani, and Carmela Marino

 

In the last decade the European public concern has been growing on the possible adverse health effects related to the use of mobile communication handsets. The ear and the auditory system could be among the primary biological targets of cellular phones emission, due to their proximity to the electromagnetic field source.

 

Our research team was involved in two Projects,  funded by EC, which addressed the topic of the potential influence of mobile phones use on the hearing system function, actually a highly sensitive biological system to exogenous and endogenous agents. The former one, GUARD (1),was focused on GSM-related experiments; no effects on the main measures auditory system status, both in animals and in human volunteers, were observed. The present paper is in the framework of the EMF nEAR (2) Project, concluded in 2007, in which the effect of UMTS electromagnetic fields on hearing were addressed. The ENEA lab was in charge for animal studies.

 

Young Sprague-Dawley male rats were locally exposed (right ear) to a SAR (Specific Absorption Rate) of 10 W/kg, two hours per day, five days per week, four weeks, at the frequency of 1946 MHz; a positive control group, i.e. made up of animals treated with an ototoxic drug (kanamycin), causing an evident damage on cochlear cells, was also scheduled. Distrortion Product Otoacoustic Emission (DPOAEs) were selected as cochlear status index. Significant reductions in DPOAEs level after the treatment may be an indicator of functional or structural damage suffered by Organ of Corti’s outer air cells (OHC), the inner ear sensory epithelium. Measurements were performed before, during and after the four weeks of treatment. Data analysis showed no change of DPOAEs level at any time of tests, neither in exposed nor in control animals. Only the ototoxic effect of kanamycin was confirmed. The same lack of effects was observed in the protocols involving human subjects scheduled in the Project. 

 

By and large, studies regarding the effects of mobile phone emissions on the auditory system both in animals (rodents, rabbits) and in humans (epidemiological studies and exposure of volunteers), dealt with various end-points, such as auditory brainstem responses, otoacoustic emissions, vestibular function, acoustic neuroma development. Results are so far inconclusive and often contradictory.

 

Our study was the first to investigate the effects of UMTS emissions on hearing in this biological model (laboratory rat). Considering the standard emissions of common cellular phones, animals were subjected to a high level of SAR (10 W/kg vs below 1 W/kg).  Despite this, we failed to demonstrate any impairment in the physiological behaviour of cochlear sensory cell due to exposure to the electromagnetic field. Possible minor or transitory effects on the same biological target (OHC) could be investigated by further morphological or molecular studies.  

 

(1) European Project GUARD “Potential adverse effects of GSM cellular phones on hearing”. 5th Framework Programme .Quality of Life and Management of Living Resources. Key Action 4: Environment and Health (FP5, QLK4-CT-2001-00150, 2002-2004).

(2) EMF nEAR Project: “Exposure at UMTS electromagnetic fields: study on potential adverse effects on hearing”, EU Commission, Framework of the program of community action in the field of public health of the EC, DG health and consumer protection (Grant Agreement n°2004127, Dec 2004 – July 2007).

 

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