Effects of Mobile Phone System (GSM-900) on the Rabbit Hearing with Auditory Brainstem Response

Effect of Electromagnetic Radiation from Mobile Phones on Auditory Brainstem Response

Mobile phones are being used by around 70% of the global population. A simple non-invasive procedure to detect early impairment of the acoustic nerve and auditory pathway is by auditory brainstem response (ABR). It's a response to the sound stimulus generated from the brainstem in the form of electrical impulses. To determine the effect of long-term usage of mobile phones on auditory brainstem responses (ABRs). This Epidemiological, cross-sectional study was undertaken at a tertiary care hospital and includes 865 individuals aged between 18 to 45 years using mobile phone for > 2 years. Users were categorized into various groups according to the minutes of mobile usage per day, years of mobile usage and total duration of mobile phone use in dominant (mobile using) and non-Dominant (non-mobile using) ears. The changes in ABR were studied in each ear to ascertain the effect of EMF exposure due to chronic mobile phone use. Mean age of subjects was 27.01 years. (M: F = 1.57:1.0). Range of mobile phone usage was from 4 to 900 min/day, with mean as 85.94 min/day. No significant differences were seen between dominant and non-dominant ears in regard to amplitudes of wave I, III and V, latencies of wave I and V and Inter peak latency (IPL) of wave I-III, III-V and I-V. No statistically significant difference for I-III, III-V and I-V IPL were found b/w two groups/ears except for usage of mobile phone for > 180 min/day in wave I-V, usage for 0-4 years in wave I-III and I-V and net hours usage for > 1500 h in wave I-V. The mean IPL in all the waves increases with the increase in years of mobile usage and is maximum in all waves in > 12 years mobile users. The long-term exposure to EMF does induce measurable changes in ABRs. Amplitude and IPLs of ABR were found comparable between the dominant and non-dominant ears using mobile phones, except for those using mobile usage for > 180 min/day and with increasing years of usage of mobile phone. Therefore, prudent use of mobile phone should be encouraged for a shorter period of time and for essential purpose only.

Association between mobile phone use and hearing impairment: a systematic review and meta-analysis

OBJECTIVES

To investigate whether a possible association of mobile phone use with hearing impairment was conducted a systematic review and meta-analysis.

CONTENT

This is a systematic review and meta-analysis. A comprehensive literature search was carried out based on the Meta-analysis of Observational Studies in Epidemiology (MOOSE) methodology using PubMed, Scopus, Web of Science, OVID, and Cochrane. The Robins-I tool was used for quality assessment and risk of bias. Two investigators independently reviewed all articles. Pooled effect size was calculated and meta-analysis was performed to compute an overall effect size.

SUMMARY

Overall, five relevant studies (two cross-sectional and three cohort studies) with 92,978 participants were included in the analysis. The studies were stratified by design, there was no significant association between mobile phone use and hearing impairment in cross-sectional studies (OR=0.94, 95% CI=0.57-1.31) and cohort studies (OR=1.09, 95% CI=0.93-1.25). In addition, the effect estimates did not differ significantly between cross-sectional and cohort studies (Q=0.50, p=0.48). Overall, the pooled odds ratio (OR) of hearing impairment was 1.07 (95% CI: 0.94-1.20), which indicates no significant association between mobile phone use and hearing impairment.

OUTLOOK

Our findings indicate no association between mobile phone use and hearing impairment. However, these findings must be interpreted with caution.

Experimental study of potential adverse effects on the auditory system of rabbits exposed to short-term GSM-1800 radiation

PURPOSE

The effects of the electromagnetic (EM) radiation emitted by a mobile phone on the central auditory system of rabbits are investigated in this paper. Auditory brainstem response (ABR) measurements were performed before and after short-term exposure to EM radiation.

MATERIALS AND METHODS

Excitation was provided by a GSM-1800 emitter placed in contact with the (randomly selected) ear of the anesthetized rabbit/subject. The latency of waves I, II, III, IV, V and the interpeak latencies I-III, I-V, III-V were recorded, for both ears, before (baseline recordings) and after 1, 15, 30, 45 and 60 minutes of exposure to the EM radiation. The repeated measures one-way analysis of variance (ANOVA) followed by the post hoc Tukey test for pairwise comparisons was performed in order to decide about the significance of the results.

RESULTS

The statistical tests indicated that, as regards the ear ipsilateral to the radiating module, the mean latencies of waves I, II, III, IV, V, I-III, I-IV after 60 min exposure, the mean latencies of waves I, III, IV, V, I-III, I-IV after 45 min exposure and the mean latencies of waves I, III, IV, V, I-IV after 30 min exposure, were significantly prolonged compared to the corresponding baseline values. Statistically significant differences were also found for certain peak and interpeak latencies for 60 min exposure as compared with the corresponding results for 1 min and 15 min exposure. No statistically significant delay was observed for the latencies before and after the exposure, for the ear contralateral to the radiation source.

CONCLUSIONS

Although we found that more than 30 min exposure to GSM-1800 radiation resulted in prolongation of certain ABR components of rabbits, further investigation may be needed into the potential adverse effects on the auditory pathways.