Risk assessment and risk management of occupational noise exposure in a passenger vehicle manufacturing enterprise

Background Occupational noise exposure has become an increasingly prominent occupational health problem endangering the physical and mental health of workers. Occupational noiseinduced deafness is the second largest occupational disease in China, behind occupational pneumoconiosis. Noise exposure risk assessment of occupational populations could guide enterprises to effectively implement risk management and protect the health of workers.

Objective This study aims to conduct risk assessment and risk management for workers exposed to noise in a passenger vehicle manufacturing enterprise.

Methods An on-site occupational hygiene investigation was conducted among workers with an equivalent sound level over an 8 h working day (L_{EX, 8h}) ≥ 80 dB(A). The assessment method for hearing loss caused by exposure to noise provided in the Guidelines for risk management of occupational noise hazard was used to assess the risk and conduct risk management for workers exposed to noise.

Results The L_{EX, 8h} of workers in selected noise-exposed positions ranged from 83.4 to 99.4 dB(A). The risk of high-frequency noise-induced hearing loss ranged from 0% to 55.2%, and the risk of occupational noise-induced deafness ranged from 0% to 37.6%. With an exposure age of less than 30 years, the highest risks of high-frequency hearing loss for chassis installers and rotating union operators were medium, and the risks of high-frequency hearing loss and occupational noise-induced deafness for coating and purging workers were fairly high and high respectively. With an exposure age of more than 30 years, the risk of high-frequency hearing loss for coating and purging workers was high, and the risks of bellow nut fixation workers, chassis installers, and rotating union operators were all medium; the coating and purging workers had the highest risk of occupational noise-induced deafness, and the associated risks were identified as high and extremely high.

Conclusion The noise exposure levels of the noise-exposed positions in the selected manufacturing enterprise exceed the national standard, and the risks of hearing loss and noise-induced deafness are fairly high. Enterprises should take engineering control measures for noise-exposed positions with extremely high and high risks, and establish hearing protection plans and strengthen management measures such as personal protection for positions with acceptable and above risks.