关键词: 金属制品业, 听力损失, 噪声暴露, 风险评价

Abstract: Objective To understand the noise exposure and hearing loss of workers in a metal products industry in Jiangbei District of Chongqing City,evaluate the risk of noise-induced hearing loss by ISO1999：2013（E）,and classify the risk according to WS/T 954-2016 "Guidelines on the risk of noise Occupational Diseases",to guide the enterprise to take targeted hearing protection measures. Methods An on-the-spot investigation was carried out in the metal products industry in Jiangbei District of Chongqing City. A total of 147 workers in the main noise operation positions of the enterprise since January 2022 were selected as the research subjects. Pure tone hearing tests were conducted to detect the 40 hours equivalent continuous A sound level（L_EX,W） of noise exposure level in the positions. The relationship between hearing loss and type of work,length of service exposed to noise and noise exposure level was analyzed. ISO 1999-2013 model was used to evaluate and manage the exposure risk of noise jobs. Results The L_EX,W range of workers in different noise jobs in the enterprise was 84.0-93.0 dB（A）,and the over-standard rate of post noise was 79.4%. Among them,the noise exceedance rate of welding,grinding,hole making,assembly,and blanking positions was 100%.The hazard classification of the workplace showed that the harm of welding and grinding positions was moderate hazardous,while that of other positions were mild hazardous. Among 147 noise workers,it was found that 26 cases（17.7%） had simple high-frequency hearing loss and 11 cases（7.5%） had high-frequency hearing loss. There was no statistically significant difference in the proportion of hearing loss among different positions（χ²=7.525,P>0.05）. With the increase of noise exposure time and noise intensity,the proportion of hearing loss showed an upward trend,the difference was statistically significant,and there was a correlation between them（χ²=7.357,13.201;r=0.218,0.287,all P<0.05）. It was predicted that the risk range of high-frequency hearing threshold loss caused by noise for workers in various positions after the age of 50 was 2.4% to 21.9%,with grinding positions being at a higher risk. The risk range of occupational noise deafness caused by noise was 0.09%,and there was a high risk in grinding,welding,and hole-making positions. Conclusion There is a high risk of high-frequency hearing loss and occupational noise deafness in grinding,welding,and hole-making posts in this enterprise. Given the medium risk and above positions,employers should implement hearing protection plans and give priority to organization and management measures,equipped with appropriate hearing protectors,organize workers for occupational health examinations,hazard notification,and hearing protection training,and regularly assess the risk of noise exposure.

Key words: Metal products industry, Hearing loss, Noise exposure, Risk evaluation