ENVIRONMENTAL NOISE EXPOSURE AND HYPOTHALAMIC–PITUITARY–ADRENAL AXIS DYSREGULATION IN PETROL PUMP ATTENDANTS: A BIOMARKER-DRIVEN CROSS-SECTIONAL STUDY

Abstract

Background: Environmental noise most common occupational and ambient health hazard and a challengeable in a workplace hazard that can lead to serious health concerns beyond hearing loss. One major mechanism is the triggering of the hypothalamic-pituitary-adrenal (HPA) axis. Petrol pump workers are continuously affected by the trafficnoise; less research was found how body response physiology. This research was done to evaluate whether exposure to environmental noise can cause the dysregulation of the HPA axis, with the use of salivary cortisol as the indicator of stress.

Methodology: Conducted a cross-sectional survey among 140 petrol pump workers located in and around the city of Puducherry. The workers were divided into 2 categories: high exposure (>85 dB, n=70) and low exposure (<85 dB, n=70). Noise levels of the environment were assessed by a noise meter. Hearing screening tests were performed using audiometry. Salivary cortisol specimens were taken from 06:30 to 07:00 AM after oral instructions were given and then analysed through enzyme immunoassay. The Mann Whitney U test, independent t-test, and Spearman's correlation were employed for the statistical evaluation.

Results: There were no significant differences (p>0.05) between the high and low exposure groups in baseline characteristics such as age height weight, and BMI. But, median salivary cortisol levels of the high-exposure group [49.7 (34.272.1) µ/dL] were significantly higher than those of the low-exposure group [25.4 (18.738.3) µ/dL] (p<0.001). Besides, a strong positive correlation between noise levels and cortisol (r =0.841, p=0.036) indicated a dose-response relationship.

Conclusion: This study reveals a marked correlation between high-level environmental noise exposure and raised salivary cortisol levels, which implicates the activation of the HPA axis. The results point to occupational noise as a stressor that triggers physiological changes and call attention to the necessity for specific measures and long-term studies to reduce the health hazards of workers exposed to noise.