Combined effects of mobile phone radiation (940 MHz) and noise (100 db, 5700- 700 Hz) on plasma level of the thyroid hormones in rats

Background and Objective: Widespread use of cell phones and increased noise pollution in surrounding environment are the most important risk factors of human health in the age of technology. The aim of this study was to investigate the effects of mobile phone radiation and noise stress on serum levels of T3 and T4 in male rats.

Materials and Methods: In this experimental study, the male Wistar rats were divided into control, exposed to cell phone radiation (940 MHz) for 1, 3 and 6 h/day, exposed to noise stress (100 db, 700-5700 Hz) for 1 h, 3 h and 6 h/day, exposed to cell phone radiation (940 MHz) and noise stress (100 db, 700-5700 Hz) for 1, 3 and 6 h/day groups. After 8 weeks, blood samples were obtained using cardiac puncture method and after serum preparation, levels of T3 and T4 were measured using ELFA method. The data were statistically analyzed using SPSS software version 19.

Results: The results indicated that serum level of T3 significantly decreased in all experimental groups compared with control animals (p < 0.001). Serum level of T4 significantly decreased in rats exposed to cell phone radiation for 3 and 6 h/day and in rats exposed to noise stress for 1, 3 and 6 h/day and in rats exposed to cell phone radiation and noise stress simultaneously for 1 and 6 h/day (p < 0.05). These changes were not observed for serum level of T4 in groups exposed to cell phone radiation for 1 h/day and in group exposed to cell phone radiation and noise stress simultaneously for 3 h/day.

Conclusion: Results of this research showed that these two physical factors can synergistically potentiate their inhibitory effects on thyroid hormones secretion and their effect is proportionally related to exposure period.