Background: Noise exposure is known as a risk factor for hearing loss and one of its effects is noise-induced stress. Cortisol as a stress hormone is used in noise-induced stress assessments.
Objectives: The aim of this study was to measure and compare saliva cortisol concentrations in the morning and evening in normal work day and rest day in both case and control groups and to assess the association between industrial noise exposure and salivary cortisol concentrations in the two groups.
Patients and Methods: This study included 200 male participants (100 industrial workers and 100 office employees). Morning and evening saliva samples were collected at 7 AM and 4 PM respectively. Noise exposure levels were assessed by sound level meter and noise dosimeter. All measurements were performed in two days; rest day and then in working day. Descriptive statistics, paired and independent sample t-test and regression analysis were used with α = 0.05.
Results: There was no significant difference between morning salivary cortisol concentrations in the two groups on the rest and work days. A significant higher level was observed comparing evening cortisol concentrations in work day with rest day in worker group, but this was not observed in the control group. The evening cortisol in the working day in worker group was significantly higher than control group.
Conclusions: Our study revealed that industrial noise exposure with levels higher than 80 dBA has a significant effect on salivary cortisol elevation.