Survey on workplace noise exposure and hearing disorders of mining workers

Abstract

Background: There are many causes of hearing loss among workers in the mining sector, and 16% of all occupational diseases worldwide are hearing disorders due to occupational noise exposure. As of 2020, a total of 10069 cases of occupational diseases were registered in Mongolia, 412 of which were loss of work ability due to noise. Objective: To study the exposure of Erdenet mining corporation workers to workplace noise and hearing loss due to it. Methods: Cross sectional study was conducted with document analysis. Workplace noise was measured with testo-815 and testo-816, and individual noise exposure was measured with Casella Noise Dosemeter. Audiometer examination results of workers in 2020 were sampled from the health indicators document. Results: A total of 3506 noise measurements were made in 2009-2020, the average level was 82±9.69 dBA, the median was 83 dBA, and 35.3% of the total measurements exceeded the maximum allowable level. Workplace noise levels are high (p <0.0001) in steel ball shop (88dBA), repair shop (87dBA) and repair and mechanical plant (87dBA). According to the level of personal noise exposure in 2018-2020, workers at the Concentrator (108 dBA), open pit (106 dBA), repair shop (89 dBA) and steel ball shop (93.1 dBA) are the most affected. According to the audiometric analysis of periodic medical examinations, 937 employees were diagnosed with auditory system disorders, of which 64.8% had hearing loss in both ears, 14.7% had hearing loss in one ear. Workers in the construction and repair shop, the repair shop, and the steel ball shop have the highest number of hearing loss cases. Conclusion: Erdenet mining corporation workers are exposed to workplace noise and 14.2% of workers have been diagnosed with hearing loss. Therefore, a hearing protection program is need to be implemented.