Non-thermal Effects Of Electromagnetic Fields Research Articles

Nonthermal effects of lifelong high-frequency electromagnetic field exposure on social memory performance in rats.

We are today surrounded almost constantly by high-frequency electromagnetic fields (EMFs) from mobile communications base stations. To date, however, there has been little concern regarding nonthermal effects of EMFs on cognition. In the present study, male and female rats were subjected to continuous far-field exposure to a frequency of 900-MHz (Global System for Mobile Communications [GSM]) or 1.966-GHz (Universal Mobile Telecommunications System [UMTS]) at 0.4 W/kg. Memory performance of adult EMF-exposed and sham-exposed female rats (at 6 months of age) and male rats (at 3 and 6 months of age) was tested using a social discrimination procedure. For this procedure, a target juvenile male was introduced to the subject's home cage for 4 min (Trial 1). After 30 min, the same target animal and a novel juvenile male were simultaneously presented to the subject for 4 min (Trial 2). Differences in sniffing duration to the familiar and novel target rats during Trial 2 were used to assess memory performance. EMF-exposed females exhibited no differences in sniffing duration compared with controls. In contrast, the sniffing durations of EMF-exposed males at 3 months of age were significantly affected. At 6 months of age, GSM-, but not UMTS-, exposed male adults showed a memory performance deficit. These findings provide new insight into the nonthermal effects of long-term high-frequency EMF exposure on memory.

Experimental system for real‐time assessment of potential changes in protein conformation induced by electromagnetic fields

A novel experimental system to distinguish between potential thermal and non-thermal effects of electromagnetic fields (EMFs) on the conformational equilibrium and folding kinetics of proteins is presented. The system comprises an exposure chamber installed within the measurement compartment of a spectropolarimeter and allows real-time observation of the circular dichroism (CD) signal of the protein during EMF exposure. An optical temperature probe monitors the temperature of the protein solution at the site of irradiation. The electromagnetic, thermal, and fluid-dynamic behavior of the system is characterized by numerical and experimental means. The number of repeated EMF on/off cycles needed for achieving a certain detection limit is determined on the basis of the experimentally assessed precision of the CD measurements. The isolated thermosensor protein GrpE of the Hsp70 chaperone system of Eschericha coli serves as the test protein. Long-term experiments show high thermal reproducibility as well as thermal stability of the experimental setup.

The Precautionary Principle: Radiofrequency Exposures from Mobile Telephones and Base Stations

Dolan and Rowley (2009) reported that the precautionary principle “is not appropriate to policy on the use of mobile telephones and the siting of base stations” because there is no established health hazard from the exposure to low-dose radiation. The guidelines [International Commission on Non-Ionizing Radiation Protection (ICNIRP) 1998] provide guidance on protection only from thermal effects (when an increase in body temperature causes injury to the tissue for a short period of time). These guidelines do not cover effects on humans or the environment from nonthermal effects [i.e., effects from electromagnetic fields (EMF) or chronic exposure that do not increase body temperature]. These nonthermal effects of EMF have been well documented by Belyaev (2005) and Sage et. al. (2007). Therefore, the precautionary principle is needed to protect the environment from these effects. Several reports have recommended use of the precautionary principle for these exposures [Herberman 2008; International Commission for Electromagnetic Safety (ICEMS) 2006, 2008; Russian National Committee on Non-Ionizing Radiation Protection 2008; Sage et al. 2007]. I do not agree with Dolan and Rowley (2009) that there is no plausible hazard to humans from the exposure to low-dose radiation. Clinical diseases caused by environmental exposures develop after a long period of biochemical changes; during this time, the exposed individual may or may not have symptoms. For example, in stomach cancer, biochemical changes may occur 10–20 years before the appearance of the cancer. Dolan and Rowley (2009) also stated that risks can be seen with other activities such as “transport (including aviation) and hot showers.” These risks result from the individual’s choices and are not comparable to exposure to electromagnetic radiation from base stations, which is a constant, chronic exposure that occurs without the individual’s knowledge and permission. The past has taught us many lessons about risk from environmental exposures. For example, the lack of full scientific proof concerning the adverse effects of asbestos and the delay of precautionary action had devasting consequencies to human health [World Commission on the Ethics of Scientific Knowledge and Technology (COMEST) 2005]. If asbestos had been banned in 1965, when the effects of asbestos on mesothelioma were plausible but unproven, the Netherlands alone would have saved approximately 52,000 victims and €30 billion for 1969–2030. An estimated 250,000–400,000 deaths from mesothelioma, lung cancer, and asbestosis caused by past asbestos exposure will occur the next 35 years in the European Union (COMEST 2005). In conclusion, concerning the exposure to electromagnetic fields, the precautionary principle should be applied to protect humans from environmental effects of non-thermal mechanisms.

Whole body exposure with GSM 900 MHz affects spatial memory in mice

Extended work has been performed worldwide on the effects of mobile phone radiation upon rats’ cognitive functions, however there is great controversy to the existence or not of deficits. The present work has been designed in order to test the effects of mobile phone radiation on spatial learning and memory in mice Mus musculus Balb/c using the Morris water maze (a hippocampal-dependent spatial memory task), since there is just one other study on mice with very low SAR level (0.05 W/kg) showing no effects. We have applied a 2 h daily dose of pulsed GSM 900 MHz radiation from commercially available mobile phone for 4 days at SAR values ranging from 0.41 to 0.98 W/kg. Statistical analysis revealed that during learning, exposed animals showed a deficit in transferring the acquired spatial information across training days (increased escape latency and distance swam, compared to the sham-exposed animals, on the first trial of training days 2–4). Moreover, during the memory probe-trial sham-exposed animals showed the expected preference for the target quadrant, while the exposed animals showed no preference, indicating that the exposed mice had deficits in consolidation and/or retrieval of the learned spatial information. Our results provide a basis for more thorough investigations considering reports on non-thermal effects of electromagnetic fields (EMFs).

Very Different Responses to Electromagnetic Fields in Binary Ionic Liquid-Water Solutions

The thermal and nonthermal effects of electromagnetic fields in the microwave to far-infrared frequency on binary mixtures of dimethylimidazolium hexafluorophosphate salts and water have been investigated by means of nonequilibrium molecular dynamics simulation. Significant alterations in dipole alignment, thermal response, and molecular mobility were found vis-a-vis zero-field conditions for mixtures of varying composition. Results indicate that ionic liquids respond most significantly to frequencies much lower than that of water in terms of both heating and nonthermal responses of dipole alignment and molecular mobility, and this was rationalized in terms of dipole moment magnitudes, rotational inertia, and translational field response.

Electromagnetic field effects on binary dimethylimidazolium-based ionic liquid/water solutions

The non-thermal effects of electromagnetic fields in the microwave to far-infrared frequency on neat dimethylimidazolium chloride and triflate salts and their binary mixtures with water have been investigated by means of non-equilibrium molecular dynamics simulation. Significant alterations in dipole alignment and molecular mobility were found vis-à-vis zero-field conditions for mixtures of varying composition. Results indicate that the dimethylimidazolium and triflate ions respond most significantly to frequencies much lower than that of water in terms of dipole alignment and molecular mobility, and this was rationalized. in terms of dipole moment magnitudes, rotational inertia and translational field response.

Extremely high frequency electromagnetic fields at low power density do not affect the division of exponential phase Saccharomyces cerevisiae cells.

Exponentially growing cells of the yeast Saccharomyces cerevisiae were exposed to electromagnetic fields in the frequency range from 41.682 GHz to 41.710 GHz in 2 MHz increments at low power densities (0.5 microW/cm2 and 50 microW/cm2) to observe possible nonthermal effects on the division of this microorganism. The electronic setup was carefully designed and tested to allow precise determination and stability of the electromagnetic field parameters as well as to minimize possible effects of external sources. Two identical test chambers were constructed in one exposure system to perform concurrent control and test experiments at every frequency step under well-controlled exposure conditions. Division of cells was assessed via time-lapse photography. Control experiments showed that the cells were dividing at submaximal rates, ensuring the possibility of observing either an increase or a decrease of the division rate. The data from several independent series of exposure experiments and from control experiments show no consistently significant differences exposed and unexposed cells. This is in contrast to previous studies claiming nonthermal effects of electromagnetic fields in this frequency range on the division of S. cerevisiae cells. Possible reasons for this difference are discussed.

Biologische Wirkungen elektromagnetischer Felder / Biological Effects of Electromagnetic Fields

This résumé deals with thermal and nonthermal effects of electromagnetic fields on man. In consideration of two aspects a limitation is necessary. Firstly, there will be discussed only direct and immediate influences on biological cells and tissues, secondly, the treatment is limited to such phenomena, for which biophysical aproximations, based on experimental data, could be developed. Hazards for the human being may occur only by thermal effects within the microwave range. Regarding frequencies below approximately 30 kHz, excitation processes cannot be excluded in exceptional cases. Thermal effects are predominant, between 30 kHz and 100 kHz, before excitations can appear. Furthermore, by comparing the electrically and magnetically induced currents with the naturally flowing currents in man caused by the brain's and heart's electrical activity, a "lower boundaryline" was estimated. Regarding electric or magnetic field strengths undercutting this boundary-line, direct effects on the central nervous system may be excluded; other mechanisms should be responsible for demonstrated biological effects. The paper closes referring to some reports--presently discussed--on experimental findings of biological effects, which are observed as a result of the influence of electromagnetic fields of small field strengths.