[Risk assessment of hearing loss of noise workers in three petrochemical enterprises].

OBJECTIVE: To evaluate the risk of noise induced hearing loss among workers in petrochemical enterprises. METHODS: Number of workers exposed to noise were recruited from three petrochemical enterprises. The noise exposure level(L_(EX, W)) of the research objects was measured, their occupational history was investigated, and the audiometric testing was carried out. The ISO 1999:2013 model was used to calculate the change of hearing threshold level and the risk of hearing loss in each post, and compared the result of model with the result of the audiometric testing. RESULTS: The median of L_(EX, W) is range from 79.8 to 85.0 dB(A). L_(EX, W) among all posts were greater than 80 dB(A) except naphtha processing operators. The result of pure tone hearing threshold test showed that the prevalence of high-frequency hearing loss among workers exposed to noise was 12.8%. According to the classification of noise operation according to the maximum value of L_(EX, W), the operator for styrene dry gas combined unit is the only post that is extremely dangerous in the department of chemical, the other posts in the department of chemical and all posts in the department of public works are exposed to light and medium noise hazards, and 62.5% the external operators of the oil refining department are under heavy and extremely hazardous. According to the evaluation result of ISO 1999:2013, the risk of high-frequency hearing loss among workers in crude distillation unit, hydrogen production unit and the electricians of electrical system is high. The measured median of noise-induced pernament threshold shift(NIPTS) among male workers in different workstation was higher than the predicted median of NIPTS of ISO 1999, and the difference was statistically significant(P<0.01), and the predicted values for four-fifths of positions were more than 10 dB lower than the measured value. CONCLUSION: The risk of noise induced hearing loss of workers in petrochemical enterprises is high.

Surveillance of Noise Exposure Level in the Manufacturing Industry - China, 2020.

INTRODUCTION: Occupational noise exposure is a widespread issue in the manufacturing industry in China. Since 2019, the National Surveillance System for Occupational Hazards in the workplace was established to understand different occupational hazards, especially occupational noise, in workplaces in China. METHODS: Both environmental and individual noise exposure levels were measured for 19,378 enterprises according to the Work Plan for Surveillance of Occupational Hazards in the Workplace (2020) issued by National Health Commission of the People's Republic of China. Median and interquartile range (IQR) were calculated to describe the distribution of the noise exposure level by industry classification, enterprise-scale, and ownership type of the enterprise. RESULTS: Overall, 25.14% of the individual noise exposure samples exceeded the Chinese national standard among the selected enterprises. The overall median of environmental noise exposure level was 82.8 dB(A) in selected enterprises, while the median of individual noise exposure level was 81.3 dB(A). The individual noise exposure level in the manufacture of metal products, manufacture of motor vehicles, mini-sized enterprises, collective enterprises and private enterprises was relatively high. CONCLUSION: Occupational noise is still one of the occupational hazards that cannot be ignored in the manufacturing industry, especially in mini-sized and private enterprises. The risk of noise exposure in the target industry is still high and will pose a threat to the health of workers.