Industrial noise: impacts on workers’ health and performance below permissible limits

Background This study investigates the adverse effects of industrial noise below permissible limits on hearing health, work performance, and work stress among workers in medium-sized enterprises.

Methods The study included two medium-sized enterprises and a total of 172 workers. A comprehensive noise assessment was conducted in both enterprises. Workplace noise levels were recorded using a Larson Davis Soun-

dAdvisor Model 831C sound level meter, following ISO 1996–2:2017 standards. The enterprises were categorized
as low-noise (mean: 60.55 dB(A), range: 55.6–66.7 dB(A)) and high-noise (mean: 78.22 dB(A), range: 76.5–80.1 dB(A)) groups. Participants’ air conduction hearing thresholds (0.5–8 kHz) were measured using an Interacoustics AS608 audiometer. Sociodemographic data were collected, and auditory complaints were assessed through face-to-face interviews. Workers completed the Job Stress Scale, while their supervisors evaluated their performance using the Job Performance Scale. Statistical significance was set at P < 0.05.

Results Our analysis revealed elevated hearing thresholds at 2000 and 4000 Hz in both ears and at 6000 Hz in the left ear among workers in the high-noise group. Additionally, employees exposed to higher noise levels demonstrated lower work performance (P < 0.05). However, no statistically significant difference was found in work stress levels between the low- and high-noise groups (P > 0.05). A significant positive correlation was observed between age

and hearing thresholds in both groups, whereas no relationship was found between age and work stress or work performance. Furthermore, no correlation was detected between work stress and work performance.

Conclusion This study highlights the serious health risks associated with industrial noise, even when exposure remains below permissible limits. The findings emphasize the need for effective noise control measures to protect workers’ health and performance.