Effect of Traffic Noise on Salivary Cortisol and Alpha-amylase Concentration while Driving

Background and Objective: Individuals constantly hear different sounds that can affect their work and living place. The present study aimed at investigating the effect of traffic noise on cortisol and salivary alpha-amylase biomarkers. Materials and Methods: The subjects were men aged 18 to 35 who performed driving activities for one hour in the laboratory. The tests were performed in two conditions of background noise (35 dBA) and traffic noise with a level of 75 dBA and saliva samples were collected from the subjects before and after driving. Finally, saliva samples were analyzed with cortisol and alpha-amylase kits and by ELISA method. The statistical method used for data analysis was SPSS software (version 24) and data analysis was performed by Wilcoxon statistical test. Results: The results of this study indicated that the concentrations of both biomarkers cortisol and alpha-amylase in background noise conditions after driving were higher than that before the start, although this increase was not significant (p> 0.05). In the presence of traffic noise with a level of 75 dBA, the concentration of both biomarkers after driving was significantly higher than that before driving. (p<0.05) Conclusion: This study demonstrated that exposure to traffic noise can increase the concentration of salivary alpha-amylase and cortisol biomarkers while driving.