Mobile phone radiation, ringtone & vibration affects anxiety-like behaviour & oxidative stress in rats
Shehu A, Mohammed A, Magaji RA, Muhammad MS. Exposure to mobile phone electromagnetic field radiation, ringtone and vibration affects anxiety-like behaviour and oxidative stress biomarkers in albino wistar rats. Metab Brain Dis. 2015 Nov 7. [Epub ahead of print]
Research on the effects of Mobile phone radio frequency emissions on biological systems has been focused on noise and vibrations as auditory stressors. This study investigated the potential effects of exposure to mobile phone electromagnetic field radiation, ringtone and vibration on anxiety-like behaviour and oxidative stress biomarkers in albino wistar rats.
Twenty five male wistar rats were randomly divided into five groups of 5 animals each: group I: exposed to mobile phone in switched off mode (control), group II: exposed to mobile phone in silent mode, group III: exposed to mobile phone in vibration mode, group IV: exposed to mobile phone in ringtone mode, group V: exposed to mobile phone in vibration and ringtone mode. The animals in group II to V were exposed to 10 min call (30 missed calls for 20 s each) per day for 4 weeks. Neurobehavioural studies for assessing anxiety were carried out 24 h after the last exposure and the animals were sacrificed. Brain samples were collected for biochemical evaluation immediately.
Results obtained showed a significant decrease (P < 0.05) in open arm duration in all the experimental groups when compared to the control. A significant decrease (P < 0.05) was also observed in catalase activity in group IV and V when compared to the control.
In conclusion, the results of the present study indicates that 4 weeks exposure to electromagnetic radiation, vibration, ringtone or both produced a significant effect on anxiety-like behavior and oxidative stress in young wistar rats.
Group I animals were exposed to mobile phone in switched off mode (Control). Group II were exposed to mobile phone in silent mode (EMR). Group III were exposed to mobile phone in vibration (V) mode. Group IV were exposed to mobile phone in ringtone (R) mode. Group V were exposed to mobile phone in Electromagnetic Radiation, Ringtone and Vibration (EMR + R + V).
The animals in group II to V were exposed to 10 min call (30 missed calls for 20 s each) per day for 4 weeks, keeping a GSM (900/1800/MHz) mobile phone in the cage between 0900 to 1200 h. Animals were allowed to move freely in the cage (21.6″ × 13″ × 7.5″) and the phones were kept in a 4″ × 2″ × 1″ wood-bottom boxes throughout the study period avoiding animal’s contact with phones (Raju et al. 2009; Sareesh et al. 2009).
A test cell phone GSM 900/1800 (model TV 20, Tecno) was used as the source of EMR. The same default ringtone was used in all the phones and using A-weighed sound level meter, the default ringtone was measured to be 76 dB. Vibration was also measured using accelerometer to be 0.47 m/s2. However, we could not regulate interference on signal reception by environmental factors and signals from other vibrating bodies in the experimental area which could rise and fall and consequently affect electromagnetic radiation in our experiment.
In this study, a significant decreased in exploratory activities as measured by decreased time spent in open arm was observed in all the treatment groups when compared to the control. This corroborate with previous studies by some investigators who reported decreased exploratory activity and increase anxiety in EMR, vibration and noise exposed animals (Abbate et al. 2004; Khirazova et al. 2012). The statistical significance also seen between groups and the control confirmed the combined effects of EMR and other stressors (Raju et al. 2009), vibration and other stressors (Dormolen and Hertog 1994) as well as noise and other stressors (Smith et al. 1993). A decrease in percentage open arm entries, head dipping frequency, rearing and, defecation was also observed although not statistically significant. The index of open arm avoidance which is a measure of anxiety (Trullas and Skolnick 1993) was also not statistically significant even though there was a general decrease in all the treatment groups when compared to the control.
The differences in the brain level of malondialdehyde (MDA) observed in the present study were not statistically significant in all the treatment groups when compared to the control even though slight decrease was observed in all the treatment groups when compared to the control ....
The absence of significant effects on MDA, SOD and GPx seen in the present study may be compensatory in nature and postulated by mobilization of other endogenous antioxidants such as nitric oxide (NO), by other antioxidant defense system in response to lesser lipid peroxidation and generation of reactive oxygen species during the exposure ....
Another possible cause of the behavioral changes could be attributed to the increased activity of the HPA axis in exposed animals....
In conclusion, the result of the present study indicates that four weeks exposure to electromagnetic radiation or in combination with either vibration, ringtone or both produced significant effect on anxiety-like behaviours probably due to oxidative stress that could lead to the activation of HPA axis in young wistar rats. More studies are warranted to unveil the mechanistic pathways via which EMR, vibration and noise exert their biological effects especially in the brain.
Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley
Electromagnetic Radiation Safety
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