|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 1 | Page : 61-63
Behavioral, biochemical, and pathological alterations induced by electromagnetic radiation in Sprague-Dawley rats
Subramani Parasuraman1, Stephanie Wong Kah Yee2, Bobby Lau Chik Chuon2, Lee Yu Ren2
1 Unit of Pharmacology, AIMST University, Bedong 08100, Kedah, Malaysia
2 Undergraduate students, Faculty of Pharmacy, AIMST University, Bedong 08100, Kedah, Malaysia
|Date of Web Publication||2-Jun-2016|
Unit of Pharmacology, Faculty of Pharmacy, AIMST University, Bedong 08100, Kedah
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Parasuraman S, Kah Yee SW, Chuon BL, Ren LY. Behavioral, biochemical, and pathological alterations induced by electromagnetic radiation in Sprague-Dawley rats. BLDE Univ J Health Sci 2016;1:61-3
|How to cite this URL:|
Parasuraman S, Kah Yee SW, Chuon BL, Ren LY. Behavioral, biochemical, and pathological alterations induced by electromagnetic radiation in Sprague-Dawley rats. BLDE Univ J Health Sci [serial online] 2016 [cited 2019 Jun 25];1:61-3. Available from: http://www.bldeujournalhs.in/text.asp?2016/1/1/61/183291
Electromagnetic radiation (EMR) is radiant energy consists of electromagnetic waves (EMWs), generated by oscillations of electric and magnetic fields. The EMWs are characterized by wavelength or frequency of their oscillations to form electromagnetic spectrum. EMR may be ionizing and nonionizing radiation (NIR).
Natural sources of ionizing radiations are accounted for approximately 86% and man-made sources of radiation such as radiation for medical uses, radiation in workplace, and development of radioactivity in the environment are accounted approximately 14% of our annual average radiation dose.  The radiation hazard to human depends on type of ionizing radiation and dose of radiation exposed. In general, neutron, proton, and alpha radiation can cause 5-20 times greater damage than the same amount of the absorbed dose of beta or gamma radiations. 
NIRs encompass the long wavelength (>100 nm) with low photon energy (<12.4 eV). NIR can penetrate into human body and the effect on health is much frequency dependent. NIRs are from both natural sources such as sunlight and man-made sources such as wireless communications.  The classical example for natural source of NIR is sun and it is emitting ultraviolet radiation continuously. In general, we are surrounded by NIR from radio, handphone/cell phone transmissions, television, computer device, and emissions from thunderstorms. The most common source for NIR is transmission lines (50-60 Hz), computer monitor (60-90 Hz), AM radio transmissions (530-1600 KHz), thunderstorms (30-300 MHz), FM radio transmission (88-108 MHz), television transmissions (50-700 MHz), handphones (850 MHz-2.4 GHz), wireless data 2.4-5 GHz and microwave ovens (2.5 GHz).  In the last few decades, many places of wireless technology are introduced for telecommunication, but the long-term health effects of those waves are unpredictable and these emissions may affect human health. Hence, the present study was planned to study the effect of EMR on behavioral, biochemical, and pathological alterations in Sprague-Dawley (SD) rats.
Healthy adult of either gender of SD rats, weighing 120-140 g were obtained from Central Animal house, AIMST University, Malaysia. The animals were housed in large, spacious polyacrylic cages at an ambient room temperature with 12-h-light/12-h-dark cycle. The animals were fed with water, and normal rats pellet ad libitum. The study was approved by AIMST University Human and Animal Ethics Committee and the study was conducted according to the Animal Research Review Panel guidelines.
The rats were divided into two groups of five animals each, namely, control and Wi-Fi radiation-exposed group. The control animals were allowed to live in Wi-Fi-free zone and Wi-Fi radiation-exposed group of animals were allowed to live in Wi-Fi zone. The strength of the Wi-Fi radiation was 2.4 GHz, 60-120 Mbps and the animals were allowed to reside in Wi-Fi zone for 90 days to monitor their behavioral, biochemical, and pathological alterations. During the study, regular food intake, water intake, and body weight changes were monitored. Behavioral alterations (locomotor activity [actophotometer], motor abilities/ muscular grip strength [rota-rod], and immobilization time [water maze]) were monitored at monthly intervals.  At the end of the study, blood sample was collected through retro-orbital sinuous for biochemical analysis under mild diethyl ether anesthesia. The serum was separated by centrifugation at 3000 RPM for 20 min at 4°C and used for the analysis of total protein, alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), urea, and creatinine. Later, the animals were sacrificed by cervical dislocation and organs such as brain, heart, liver, and kidney were collected and weighed.  Part of the brain, heart, liver, and kidney will be preserved in 10% neutral formalin for histopathological studies. Part of the liver sample will be preserved in deep frizzed at the temperature of − 80°C for the estimation of oxidative stress parameters (data not presented).
The results of body weight analysis of the animals in Wi-Fi radiation-exposed group showed increased in body weight, but the results were not significant [Figure 1]. Wi-Fi radiation exposed animals showed significant behavior alterations (decreased locomotor activity, immobilization time, and grip strength) from 60 th day of experiment onward [Table 1].
|Figure 1: Effect of Wi-Fi on body weight of Sprague-Dawley rats. All the values are mean ± standard error of the mean (n = 5)|
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|Table 1: Effect of Wi - Fi radiation on behavioral functions of Sprague-Dawley rats|
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In biochemical analysis, Wi-Fi radiation-exposed animals showed a significant increase in levels of total protein, AST, ALT, ALP, urea, and creatinine compared with control animals [Table 2]. The histopathological analysis of brain of control animals showed normal architecture and Wi-Fi radiation-exposed animals showed pyknosis and apoptosis in brain cortex. No significant changes in brain cerebellum, heart, liver, and kidney were observed [Figure 2].
|Figure 2: Histological features of the brain of Wi-Fi radiation exposed animals. (a) Section from brain cortex of Wi-Fi radiation exposed animals shows pyknotic nucleus (H and E, ×100). (b and C) Section from brain cortex of Wi- Fi radiation exposed animals shows pyknotic nucleus and apoptosis (H and E, ×400)|
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|Table 2: Effects of Wi - Fi radiation on serum biochemical parameters of Sprague-Dawley rats|
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Erogul et al. studied the effect of 900 MHz cell phone tower radiation in male volunteer and found that EMR emitted by cell phone tower does not have any effect on short-term and they concluded that the long-term exposure may lead to behavioral alterations or structural changes of male germ cells.  The hippocampus is the part of the brain which is involved in origination and memory forming which is affected by GSM 900 EMR. A GSM 900 EMR also causing structural damage to the brain due to albumin leakage from blood brain barrier, reduced locomotor activity, increased grooming, and increased basal corticosterone levels.  Irmak et al. studied the effect of influence of EMR of a digital GSM mobile telephone (900 MHz) on oxidative and antioxidant levels in rabbits and found that EMR radiation increased the levels of serum superoxide dismutase and decreased the levels of nitric oxide.  The acute exposure of continuous wave at 2450 MHz EMR caused DNA strand breaks in brain cells of rodents. 
This study concludes that the chronic exposure of EMR/Wi-Fi radiation caused behavioral alterations, alterations in liver metabolic enzyme levels and pyknotic nucleus and apoptosis in brain cortex.
The authors would like to thank Dr. Urmila Banik, Department of Pathology, Faculty of Medicine, AIMST University, for analyzing the histopathology slides and Clinipath Malaysia Sdn Bhd, Selangor for helping biochemical analysis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2]