Abstract

Background: Simultaneous exposure to noise and organic solvents such as styrene is an indispensable part of today’s industries. Numerous studies were done related to ototoxic effects of co-exposure to noise and styrene while some evidences showed the adverse effects of such exposure on other organs. In this study, we aimed to assess the subacute effects of combined exposure to noise and styrene on rats’ lung tissue. Materials and Methods: Twenty-four Wistar male rats were divided in four groups including: A) control, B) rats exposed to 100 dB octave band of noise, C) rats exposed to 750 ppm styrene alone, and D) rats exposed to combination of 100 dB noise and 750 ppm styrene. Following the last day of exposure, the rats were euthanized and their lung tissues were excised, homogenized and assayed for biological analysis of malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD). The results were analyzed using SPSS software. Results: MDA increased significantly (P < 0.001) at the end of experiment in the group exposed to styrene and noise-styrene. GSH concentrations decreased significantly in styrene and noise-styrene group (P < 0.001). SOD (P < 0.001) and CAT (P < 0.05) activities were determined to be significantly lower for the styrene and noise-styrene groups compared to the control group. Conclusions: In conclusion, our results indicated that exposure to combination of noise and styrene caused oxidative stress, increased lipid peroxidation, and antioxidant depletion. These results appear to support the fact that co-exposure to noise and styrene might cause oxidative stress-induced damage to the lung tissue. Since simultaneous exposure to noise and styrene has an additive effect in this regard, further studies are necessary to be carried out on the effects of noise and organic solvents co-exposure.