Health effects and standard threshold shift among workers in a noisy working environment

Abstract

Introduction: Working in a noisy environment is a risk for employee hearing health. Standard threshold shift (STS) can be used as a screening method to detect early indications of hearing deterioration. Objective: To investigate health effects related to STS in motor compressor workers. Methods: A cross sectional study of 464 motor compressor workers was conducted including hearing health examination by audiometer, and noise level in the workplace was monitored. Workers who reported having hobbies relating to noise, e.g. gun shooting, or a personal history of disease relating to the ear were excluded. The relationship between health effects and workers with STS was studied. Results: There were more men 81.90% (aged range 31-40 years old) than women working for the company. The average continuous noise level in the workplace was 84.14 ± 5.21 dB(A). The study showed that working at the factory for more than 14 years (OR= 3.84, 95%CI 1.54-9.56) and being exposed to noise at least 8 hours a day (OR = 2.12, 95%CI = 1.02-4.40) effected to STS. Workers with STS showed significant communication difficulties (OR = 1.89, 95%CI = 1.03-3.49) and stress/nausea more than workers without STS (OR = 1.54, 95%CI = 0.90-2.65) although not statistically significant. Conclusions: Workers exposed to continuous noise in the motor compressor industry are at risk of STS. Duration of exposure to noise is a key factor in respect of harm to hearing health. STS could be used as a tool to screen workers who have hearing health problems.