Analysis of noise hazard characteristics in automobile sand casting industry / 公共卫生与预防医学

ABSTRACT

Objective To study the characteristics of noise hazards in automobile sand casting industry and understand the impact of noise on the health of automobile foundry workers, and to provide scientific data support for the control of noise hazards. Methods An automobile sand casting enterprise was selected as the research object. The post noise intensity test results from 2010 to 2019, the noise spectrum test results of each post in 2019, and the prevalence of occupational noise deafness in the 10 years from 2010 to 2019 were analyzed and sorted out. Using chi-square test and t-test the noise hazard characteristics and noise intensity changes were statistically analyzed. Results 1. The noise LEX.8h exceeding standard rate of foundry enterprises in the 10 years from 2010 to 2019 was not statistically significant（χ2=6.76, P=0.66), and the mean value of noise LEX.8h fluctuated horizontally in the 10 years, which was basically stable between 80 - 90 dB (A). 2. The mean value of noise intensity of sand falling, sand preparation, cleaning and shot blasting in the first five years was significantly different compared to that in the last five years. There was no statistically significant difference in other posts. 3. Among all posts in the foundry sand casting industry, the noise spectrum of core-making and cleaning posts was mainly medium and high frequency, while the noise spectrum of other posts was mainly medium and low frequency. 4, Cases of occupational noise deafness were mainly concentrated in cleaning and polishing workers, melting chemical workers, inspectors and other types of workers. Conclusions The noise hazards in the automobile foundry sand casting industry are mainly concentrated on the posts of molding, and sand falling, and the noise intensity and the over standard rate remain high in the past 10 years. The noise of each post is mainly medium and low frequency, and the noise of a few individual posts is mainly medium and high frequency. In recent years, due to the automatic renewal of equipment, the noise intensity of some posts such as sand dropping, sand mixing, cleaning and shot blasting has decreased, but the overall noise exceeding standard rate has basically not changed, and the noise hazard is still serious. The noise hazard of foundry sand casting enterprises is difficult to be controlled, and the risk of hearing loss of foundry workers is still high.