Factors Associated with Occupational Hearing Loss among StoneMortar Workers in Phayao Province, Northern Thailand

Abstract

Objective: Noise pollution is an unwanted phenomenon that affects human health and can lead to occupational hearingloss in exposed workers. The stone-mortar industry is one of the processes which can create a noise hazard. This studyaimed to explore the factors associated with occupational hearing loss among stone-mortar workers in Phayao Province, Northern Thailand.Material and Methods: A cross-sectional study was conducted 27 stone-mortar workers who were interviewed with a questionnaire. Pure-tone hearing thresholds were measured using audiometry. The data were analyzed using Mann-Whitney U test, Spearman’s rank correlation test and Kruskal-Wallis test and Multiple linear regression analysis.Results: The study found a significant difference between age and high frequency hearing loss in both right and left ears (p-values 0.024 and 0.049, respectively). There were significant correlations between working hours per day and high frequency hearing loss in both right and left ears (p-values 0.030 and 0.042, respectively). Multiple linear regression analysis found increasing age was associated with high frequency hearing loss in both right and left ears (p-values 0.033 and 0.017, respectively) after adjusting for number of years worked, working hours per day, and use of personal protective equipment as random variables.Conclusion: All stone-mortar factories produce noise pollution. Therefore, the local policy makers should emphasize reducing noise pollution from stone factories and surveillance of occupational hearing loss to improve the quality of life of the people who work in such factories.