Noise Pollution and Its Correlations with Occupational Noise-Induced Hearing Loss in Cement Plants in Vietnam.

Tinh Thai,Ales Bernatik,Petr Kučera

doi:10.3390/ijerph18084229

Abstract

Noise-Induced Hearing Loss (NIHL) is a global issue that is caused by many factors. The purpose of this study was to survey noise level to identify NIHL and its relationship with other factors in cement plants in Vietnam. Noise level was measured at one cement plant and three cement grinding stations located in the South of Vietnam. The audiometric data of exposed workers were surveyed to determine NIHL. Finally, the relationship between NIHL and noise level in cement plants was determined. The results show that noise level in almost all processes exceeded the permissible exposure limit (PEL). In this study, 42 cases (10% of exposed workers) with occupational NIHL were found with mean age (SD) of 49 (9.0) years. All NIHL cases were found in the departments in which the noise level exceeded the PEL, which included quarry (n = 16), maintenance (n = 12), production (n = 10), co-waste processing (n = 3) and quality assurance (n = 1). There was a positive and significant correlation between the NIHL and the excessive noise exposure in the cement plants (r = 0.89, p = 0.04).

Highlights

Noise-induced hearing loss (NIHL) has long been recognized as an occupational disease, amongst copper workers from hammering on metal, blacksmiths in the 18th century, and shipbuilders or boilermakers after the Industrial Revolution [1]
Noise sources in a cement plant are varied and mainly include gas dynamic noise, which is induced by blower, air compressor and dust collector operation; mechanical noise, which is induced by machine operation, such as crushers, mills; electric–magnetic noise, which is induced by electric motors
Long-term exposure to excessive noise pressure levels exceeding the permissible exposure limit (PEL) (85 dBA) within cement manufacturing processes could lead to NIHL

Summary

Introduction

Noise-induced hearing loss (NIHL) has long been recognized as an occupational disease, amongst copper workers from hammering on metal, blacksmiths in the 18th century, and shipbuilders or boilermakers after the Industrial Revolution [1]. Noise sources in a cement plant are varied and mainly include gas dynamic noise, which is induced by blower, air compressor and dust collector operation; mechanical noise, which is induced by machine operation, such as crushers, mills; electric–magnetic noise, which is induced by electric motors. The noise levels in some production areas, such as in the cement mill, air compressor, blower or crusher, in the cement grinding station ranged between 89 and 105 dBA and exceeded the Vietnamese permissible exposure limit (PEL) (85 dBA/08 working hours) [4]. Workers who are under long-term exposure to excessive noise level can develop noise-induced hearing loss (NIHL) [5]

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Results

Conclusion