Prevalence of coal workers' pneumoconiosis in a coal mine in Shanxi province

ObjectiveTo reveal incidence characteristics of coal workers'pneumoconiosis(CWP)in coal mine workers with different type of work and the year of first dust exposure.MethodsA retrospective cohort was established for 4 771 coal workers in a coal mine in Shanxi province,with 42 years of follow-up from 1970.The incidence rate and accumulative incidence rate of CWP in the dust exposure workers with different type of work and the year of first dust exposure were analyzed.ResultsThere were 193 CWP patients were diagnosed during the follow-up period in the workers,with a crude incidence rate of 4.05%.The incidence rate of the tunneling,mining,combining,and helping workers were 25.10%,8.50%,3.60%,and 0.19%,respectively,with statistically significant difference(χ²=644.12,P<0.001).During 42 years of follow-up,the cumulative incidence rates were 84.25%,41.04%,33.60%, and 1.03% for tunneling,mining,combining and helping workers.The cumulative incidence rate was significantly different among the workers with different type of work(χ²=543.73,P<0.001).The workers with the same follow-up years(32 years)but different year of first dust exposure(from 1970 and from 1980)had significant different cumulative incidence rate(13.56% vs.13.51%)(χ²=217.12,P<0.001).ConclusionThe cumulative incidence rate of CWP in tunneling worker was higher than in coal mine workers with other type of work and the rate decreased with the delay of the year of first dust exposure.