Ayşegül Akar

Effects of a 900-MHz Electromagnetic Field on Oxidative Stress Parameters in Rat Lymphoid Organs, Polymorphonuclear Leukocytes and Plasma

BACKGROUND AND AIMS The present study investigated the effects of a 900-MHz electromagnetic field (EMF) for 2 h/day for 45 days on lymphoid organs (spleen, thymus, bone marrow), polymorphonuclear leukocytes (PMNs) and plasma of rats, focusing on changes in the enzymatic and nonenzymatic antioxidant system. We determined whether there is any difference between immature and mature rats in terms of oxidative damage caused by EMF and tested recovery groups to determine whether EMF-induced damage is reversible in immature and mature rats. METHODS Twenty four immature and 24 mature rats were divided randomly and equally into six groups as follows: two control groups, immature (2 weeks old) and mature (10 weeks old); two groups were exposed to 900 MHz (28.2 ± 2.1 V/m) EMF for 2 h/day for 45 days. Two recovery groups were kept for 15 days after EMF exposure. RESULTS Substantial, deleterious biochemical changes were observed in oxidative stress metabolism after EMF exposure. Antioxidant enzyme activity, glutathione levels in lymphoid organs and the antioxidant capacity of the plasma decreased, but lipid peroxidation and nitric oxide levels in PMNs and plasma and also myeloperoxidase activity in PMNs increased. Oxidative damage was tissue specific and improvements seen after the recovery period were limited, especially in immature rats. CONCLUSIONS In the present study, much higher levels of irreversible oxidative damage were observed in the major lymphoid organs of immature rats than in mature rats.

Oxidative stress induced by 1.8 GHz radio frequency electromagnetic radiation and effects of garlic extract in rats.

Abstract Purpose: We aimed to study the oxidative damage induced by radiofrequency electromagnetic radiation (RF-EMR) emitted by mobile telephones and the protective effect of garlic extract used as an anti-oxidant against this damage. Materials and methods: A total of 66 albino Wistar rats were divided into three groups. The first group of rats was given 1.8 GHz, 0.4 W/kg specific absorption rate (SAR) for 1 h a day for three weeks. The second group was given 500 mg/kg garlic extract in addition to RF-EMR. The third group of rats was used as the control group. At the end of the study, blood and brain tissue samples were collected from the rats. Results: After the RF-EMR exposed, the advanced oxidation protein product (AOPP) levels of brain tissue increased compared with the control group (p < 0.001). Garlic administration accompanying the RF-EMR, on the other hand, significantly reduced AOPP levels in brain tissue (p < 0.001). The serum nitric oxide (NO) levels significantly increased both in the first and second group (p < 0.001). However, in the group for which garlic administration accompanied that of RF-EMR, there was no difference in serum NO levels compared with the RF-EMR exposed group (p > 0.05). There was no significant difference among the groups with respect to malondialdehyde (MDA) levels in brain tissue and blood samples (p > 0.05). Similarly, no difference was detected among the groups regarding serum paroxonase (PON) levels (p > 0.05). We did not detect any PON levels in the brain tissue. Conclusions: The exposure of RF-EMR similar to 1.8 GHz Global system for mobile communication (GSM) leads to protein oxidation in brain tissue and an increase in serum NO. We observed that garlic administration reduced protein oxidation in brain tissue and that it did not have any effects on serum NO levels.

Effect of 900 MHz radiofrequency radiation on oxidative stress in rat brain and serum.

The increasing use of mobile telephones raises the question of possible adverse effects of the electromagnetic fields (EMF) that these phones produce. In this study, we examined the oxidative stress in the brain tissue and serum of rats that resulted from exposure to a 900-MHz EMF at a whole body average specific absorption rate (SAR) of 1.08 W/kg for 1 h/day for 3 weeks. We also examined the antioxidant effect of garlic powder (500 mg/kg/day) given orally to EMF-exposed rats. We found that malondialdehyde (MDA) (p < 0.001) and advanced oxidation protein product (AOPP) (p < 0.05) increased in rat brain tissue exposed to the EMF and that garlic reduced these effects (p < 0.05). There was no significant difference in the nitric oxide (NO) levels in the brain. Paraoxonase (PON) was not detected in the brain. There was a significant increase in the levels of NO (p < 0.001) detected in the serum after EMF exposure, and garlic intake did not affect this increase in NO. Our results suggest that there is a significant increase in brain lipid and protein oxidation after electromagnetic radiation (EMR) exposure and that garlic has a protective effect against this oxidative stress.

Cytotoxic and genotoxic effects of high-frequency electromagnetic fields (GSM 1800 MHz) on immature and mature rats.

We investigated the cytogenotoxic effects of high frequency electromagnetic fields (HF-EMF) for 45 day and the effect of a recovery period of 15 day after exposure to EMF on bone marrow cells of immature and mature rats. The animals in treatment groups were exposed to 1800 MHz EMF at SAR of 0.37 W/kg and 0.49 W/kg for 2h/day for 45 day. Two recovery groups were kept for a recovery period of 15 day without EMF after exposure to HF-EMF. Two control groups for both immature and mature rats were also included. Significant differences were also observed in chromosome aberrations (CA), micronucleus (MN) frequency, mitotic index (MI) and ratio of polychromatic erythrocytes (PCEs) in all treatment groups. The cytogenotoxic damage was more remarkable in immature rats and, the recovery period did not improve this damage in immature rats. Because much higher and irreversible cytogenotoxic damage was observed in immature rats than in mature rats, further studies are needed to understand effects of EMF on DNA damage and DNA repair, and to determine safe limits for environment and human, especially for children.

Evaluation of the cytogenotoxic damage in immature and mature rats exposed to 900 MHz radiofrequency electromagnetic fields

Abstract Purpose: One of the most important issues regarding radiofrequency electromagnetic fields (RF-EMF) is their effect on genetic material. Therefore, we investigated the cytogenotoxic effects of 900 MHz radiofrequency electromagnetic fields (RF-EMF) and the effect of a recovery period after exposure to RF-EMF on bone marrow cells of immature and mature rats. Materials and methods: The immature and mature rats in treatment groups were exposed to RF-EMF for 2 h/day for 45 days. Average electrical field values for immature and mature rats were 28.1 ± 4.8 V/m and 20.0 ± 3.2 V/m, respectively. Whole-body specific absorption rate (SAR) values for immature and mature rats were in the range of 0.38–0.78 W/kg, and 0.31–0.52 W/kg during the 45 days, respectively. Two recovery groups were kept for 15 days after RF-EMF exposure. Results: Significant differences were observed in chromosome aberrations (CA), micronucleus (MN) frequency, mitotic index (MI) and ratio of polychromatic erythrocytes (PCE) in all treatment and recovery groups. The cytogenotoxic damage in immature rats was statistically higher than the mature rats. The recovery period did not reduce the damage to the same extent as the corresponding control groups. Conclusions: The exposure of RF-EMF leads to cytotoxic and genotoxic damage in immature and mature rats. More sensitive studies are required to elucidate the possible carcinogenic risk of EMF exposure in humans, especially children.

Effects of low level electromagnetic field exposure at 2.45 GHz on rat cornea

Abstract Purpose: To investigate the effects of low level electromagnetic field (low level-EMF) exposure, as frequently encountered in daily life, on the normal rat cornea using histological and stereological method. Methods: Twenty-two adult male Wistar rats were randomly divided into two groups: Study group (n = 11) and control group (n = 11). Rats in the study group were exposed to 2.45 GHz microwave (MW) radiation (11.96 ± 0.89 V/m), 0.25 W/kg specific absorption rate (SAR) for 2 hours each day for 21 days. The corneal thickness and the anterior epithelium corneal thickness were measured using two different methods. Results: Using the histological method, the mean corneal thicknesses in the control and study group were 278.9 ± 54.5 μm, and 272.4 ± 85.6 μm, respectively. There was no statistically significant difference between the groups (p > 0.05). The anterior corneal epithelium thickness was 28.1 ± 4.9 μm in the control group and 31.7 ± 5.5 μm in the study group. There were statistically differences between the groups with regard to the thickness of anterior epithelium (p < 0.05). In the measurement made by the stereological method, the percentage of the cornea occupied by anterior corneal epithelium was 15.94% in the control group and 17.9% in the study group. Despite the fact that there was a relation between increased anterior epithelial area (AEA) and radiation exposure, no statistically significant relationship in area fraction of each compartment was found between the control and study groups. Conclusions: Results of this preliminary study show that exposure to MW radiation might cause alterations in the rat cornea.

Effects of electromagnetic field (1.8/0.9 GHz) exposure on growth plate in growing rats

The purpose of this study was to determine the effects of whole-body electromagnetic field (EMF) exposure on growth plates in growing male rats. Two groups of rats were exposed to either 900 MHz EMF or 1800 MHz EMF 2 h/day for 90 days. Sham control rats were kept under similar conditions without exposure to the EMF. The rats in the EMF group experienced a more rapid weight gain and increase in length (p < 0.05). Calcium, growth hormone, estradiol and testosterone levels in the EMF groups were higher (p < 0.05). The Safranin O staining density of femoral growth plate was lowest in the reserve zone of rats exposed to 1800 MHz and was increased in the proliferative zone of the control group (p < 0.05). The trabecular zone was thinnest among all zones and the reserve and proliferative zones were thicker (p < 0.05) than other zones in 1800 MHz group.In conclusion, 1800 MHz and 900 MHz EMF may cause prolong the growth phase in growing rats.

Total Electron Stopping Powers and CSDA-Ranges from 20 eV to 10 MeV Electron Energies for Components of DNA and RNA

Abstract An appropriate formula for the total stopping power of electrons of initial kinetic energy from 20 eV to 10 MeV in some biological materials is presented. The continuous slowing down approximation-range (CSDA-range) from the total stopping power is also made. The collisional stopping power formula is evaluated using Generalized Oscillator Strength (GOS) model and exchange correction on the inelastic differential cross section (IDCS) given by [M. Inokuti, Rev. Mod. Phys. 43 (1971) 297–347] and the radiative stopping power formula is calculated from the bremsstrahlung differential cross section (DCS) given by [H.W. Koch, J.W. Motz, Rev. Mod. Phys. 31 (4) (1959) 920–955]. Calculation of the total stopping powers (SPs) and CSDA-range for biological compounds: C 5 H 5 N 5 (adenine), C 5 H 5 N 5 O (guanine), C 4 H 5 N 3 O (cytosine), C 5 H 6 N 2 O 2 (thymine), C 4 H 4 N 2 O 2 (uracil), C 4 H 8 O (tetrahydrofuran), C 4 H 8 O 2 (3-hydroxytetrahydrofuran), C 5 H 10 O 2 ( α -tetrahydrofurfuryl alcohol), H 3 PO 4 (phosphoric acid), C 19 H 26 N 8 O 13 P 2 (thymine adenine DNA) have been introduced for incident electrons in the 20 eV–10 MeV energy range. The calculated results have been compared with experimental data, PENELOPE program results and other theoretical results. The calculated results of total stopping power and CSDA-ranges for electrons in energy range from 20 eV to 10 MeV are found to be in good agreement to within 8% with available data.

What is adverse effect of wireless local area network, using 2.45 GHz, on the reproductive system?

Abstract Aim: To investigate the inflammatory effect and testicular damage on rats exposed to low level of electromagnetic fields (EMF) at 2.45 GHz microwave radiation. Methods: Twenty two Wistar rats were divided into two groups. Group 1 was the control group and not exposed to EMF. Group 2 was exposed to low level EMF (average E-field 3.68 ± 0.36 V/m, whole body average SAR, 0.0233 W/kg, in 10 g tissue) at 2.45 GHz for 1 hour/day for 30 consecutive days. At the end of the study, interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-32 (IL-32), C-reactive protein (CRP) were measured in rat serum and IL-6, IL-10, IL-32 were measured in rat testis tissue. Furthermore, testicular tissues were evaluated histopathologically in terms of spermatogenesis and coagulation necrosis. Results: Serum IL-6 and CRP levels were found to be significantly different in the study group compared to the control group (p < .05), but no significant difference was found in serum IL-10, IL-32 levels and testis tissue IL-6, IL-10, IL-32 levels compared to the control group (p > .05). On the other hand, histopathological evaluation of testicular tissue revealed a significant difference in necrosis and spermatogenesis when compared with the control group (p < .05). Conclusions: It may be concluded that low level EMF at 2.45 GHz increases inflammation and testicular damage and negative impact on male reproductive system function.