Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats
Sırav B, Seyhan N. Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats.J Chem Neuroanat. 2015 Dec 23. pii: S0891-0618(15)00106-4. doi: 10.1016/j.jchemneu.2015.12.
Highlights
• Exposure to the pulse modulated radio-frequency radiation could lead to increase in the permeability of blood–brain barrier.
• New researches are needed to discuss the effects of radio-frequency radiation on children.
• Efforts have to be made to understand the mechanisms of the interaction of radio-frequency radiation and the central nervous system.
Abstract
With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood-brain barrier of rats.
Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups.
For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood-brain barrier found to be increased with respect to the controls (p<0 .01="" 1800mhz="" animals="" br="" effective="" exposure="" found="" male="" modulated="" more="" nbsp="" on="" p="" pulse="" radiation="" radio-frequency="" the="" was="">
For female groups; dye contents in the whole brains were 0.14±0.01mg% in the control, 0.24±0.03mg% in 900MHz exposed and 0.14±0.02mg% in 1800MHz exposed animals. No statistical variance found between the control and 1800MHz exposed animals (p>0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20 minutes pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective. and it could be concluded that this result may due to the physiological differences between female and male animals.
The results of this study suggest that mobile phone radiation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown.
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Blood–brain barrier (BBB) behaves like a selective filter which does not allow most of molecules to enter the brain under normal physiological condition (Koziara et al., 2006). It is due to tight junctions linking together endothelial cells of cerebral blood vessels. Except for lipohilic molecules which able to cross the cell inner- and outer membrane, all blood-borne materials are carried across endothelial cells by active and regulated mechanisms. Under some pathological conditions (such as hyperthermia, acute rise in arterial pressure, brain trauma, old age, MS and Alzheimer diseases, diabetes, exposure to non-ionizing/ionizing radiations…) BBB permeability increases for substances normally excluded such as large molecules that have no lipid solubility.
For the 900 MHz and 1800 MHz exposed groups the average SAR values were found to be 0.02 W/kg. For the control group SAR value was 5.4 × 10−5 W/kg. The legally acceptable SAR level limit is changing from country to country. The SAR limit of the Federal Communication Commission (FCC) is 1.6 W/kg for 1 g of tissue in the USA. This standard is also used in Canada and Australia, while the SAR standard used by the European Union is 2 W/kg for 10 g of tissue. Although the worst case approach, evaluated SAR values are far below the limits. Since the SAR values in this study is 0.02 W/kg; this SAR level have no effect on the rat's body temperature (ICNIRP, 1998), so one can call the exposure level used in this study as non-thermal. The exposure systems can affect the permeability of BBB by restrained stress or thermal stress. Environmental stress, hypoxia, alcohol, or fatigue can have some effects on the Purkinje cells, and glia cells. There were no such stress sources in the exposure procedures.
In this study, these results support the hypothesis that 900 MHz and 1800 MHz pulse modulated RFR could lead to increase in the permeability of BBB. On the basis of the current state of knowledge there are still gaps in the biological effects of RF electromagnetic fields such as children studies. Children are increasingly growing users of wireless technology and they are assumed to be more sensitive to exposures to physical, chemical or biological agents. Children get more energy in the RFR range than adults because their tissue have a larger number of ions and also a higher conductivity (Gabriel, 2005). Thus, new researches are needed to discuss the effects of RFR on children, epidemiological studies including long-term exposure, as well as other diseases. Efforts have to be made to understand the mechanisms of the interaction of RFR and the central nervous system. These mechanisms would help to explain possible biological effects.
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Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley
Electromagnetic Radiation Safety
Website: http://www.saferemr.com
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