单纯接触温石棉人员癌症死亡队列研究的荟萃分析

目的　用荟萃 (meta)分析探讨单纯接触温石棉人员的癌症是否高发。方法　凡满足明确是单纯温石棉暴露且为癌症死亡率队列研究的资料均被纳入研究对象 ,以直接法与随机效应模型法计算主要部位癌症的标准化死亡比 (SMR)及其 95 %可信区间 ,计算Q统计量与Z值检验研究结果异质性及其来源。结果　共有 2 6个队列符合入选标准 ,平均间皮瘤死亡百分比为 0 4 2 % ,全死因、全癌亡、呼吸系统全癌、肺癌和胃癌的meta SMR显著上升 ,分别为 1 2 8、1 2 6、2 2 4、2 2 9与1 2 7。肺癌的meta SMR在纺织 (3 6 4 )、石棉制品加工 (3 0 7)、采选矿 (2 2 4 )和石棉水泥制品加工(1 2 2 )显著升高 ,胃癌的meta SMR在石棉制品加工 (1 4 8)显著升高。其余部位癌症的meta SMR均无显著意义。结论　单纯温石棉暴露能使作业人员肺癌、间皮瘤显著高发 ,与其他部位癌症似无病因联系。

A meta-analysis of cohort studies on cancer mortality among workers exposure to chrysotile fiber alone

Objective To determine there was excessive risk of malignant tumors or not among workers exposure to chrysotile fiber alone by applying a meta-analysis technique. Methods All data meeting the criteria of cohort studies on cancer mortality among workers exposed only to chrysotile would incorporate into the meta-analysis. The pooled standardized mortality ratios (SMR) and their corresponding 95% confidence intervals (95% CI ) for main cancer sites were calculated using two approaches of unweighted ratio and random effects model. The heterogeneity and its sources of the results were examined with a Q -statistic and Z -score test.Results 26 chrysotile-exposed alone cohorts were summarized. The significantly elevated meta-SMRs for all deaths (1.28), all cancers (1.26), cancers of respiratory organs (2.24), cancer of lung (2.29) and cancer of stomach (1.27) were observed. The significantly elevated meta-SMRs for lung cancer within occupational strata were observed among textile workers (3.64), asbestos products manufacturers (3.07), miners and millers (2.24), cement products workers (1.22), and for stomach cancer among asbestos products manufacturers (1.48). Meta-SMRs for cancers at other sites were not significant. Conclusion There were excessive risks of lung cancer and mesothelioma among workers exposure to chrysotile fiber alone, and likely no convincing indication of an etiological association between chrysotile exposure and cancers at other sites.