广西锡矿矿尘致矽肺的危险度评价

目的　探索锡矿矿尘的致病强度和最低无害作用水平。方法　选择广西锡矿 1 960～1 974年期间接触矿尘至少 1年的男性矿工 4 471名建立回顾性接尘队列 ,并用以同一方法建立的瓷厂接尘队列与其进行比较 ;采用SAS中的生存检验分析软件进行非参数估算 ,评价锡矿矿尘致矽肺的危险度。结果　随访到 1 994年底 ,锡矿队列工人矽肺发病 971例 (2 1 .7% ) ,其中 81 %的病例为 1 958年前接尘对象 ,累积接触总粉尘量 (CTD)与矽肺危险度明显相关 :当CTD <50mg·m- 3·年 - 1 时 ,矽肺危险度为 0 .0 1 2 ;CTD >40 0mg·m- 3·年 - 1 时 ,矽肺危险度上升到 0 .971。瓷厂接尘工人CTD >40 0mg·m- 3·年 - 1 时 ,矽肺危险度仅为 0 .369。结论　锡矿接触矿尘工人的矽肺发病与CTD明显相关 ;锡矿矿尘导致矽肺的危险性远比瓷厂的陶瓷尘严重

Assessnent of risk for tin mine dust in Guangxi

OBJECTIVE: To explore the minimum observed adverse effect level(LOAEL) and intensity of pathogenesis of tin mine dust. METHODS: A cohort study design with retrospective assessment of exposure was used. Selected 4,471 male tin miners who were exposed to tin at least one year during 1960 to 1974 and were compared with 4,797 pottery dust exposed workers in the same way designed. Statistical analysis system SAS, PROC LIFETEST were used to perform the non-parameter calculation by Life Table method. RESULTS: Tin mine cohort subjects were followed up to December 31, 1994. The percentage of miners who developed silicosis was 21.7% (971/4,471). 81% of the patients had been exposed to dust before 1958. The cumulative total dust exposure(CTD) was significantly correlated with silicosis risk. The risk of silicosis was 0.012 when CTD was less than 50 mg/m-3.year-1. The risk of silicosis was increased to 0.971 when CTD was beyond 400 mg.m-3.year-1. However, the risk of silicosis was only 0.369 for dust exposed workers in pottery factories when CTD was beyond 400 mg.m-3.year-1. CONCLUSION: There was significant relationship between cumulative dust exposure and the incidence of silicosis in tin exposed workers. And silicosis induced by tin mine dust is more serious than the pottery dust.