A historical cohort study of carpenters exposed to low dose asbestos in a shipyard

进行了两项历史队列研究，以调查低剂量石棉暴露对职业环境中死亡率的影响。其中一个队列由153名男性木匠组成，1976年在一家造船厂工作。他们在船上建造房间时，曾断断续续地暴露在石棉中很短一段时间。另一组受试者为199名工人(140名男性和59名女性)，他们在1946年至1958年间受雇于一座毒砂矿。这组工人被设为“阳性”对照组，以比较石棉和砷的致癌程度。从1976年到1999年5月31日，对木匠进行了跟踪调查，在153名研究对象中，有145人被确定了身份。其中20人已经死亡。总死亡的SMR，调整为5岁和日历年在5年期间的死亡率，日本普通人群的SMR为1.2，其95%可信区间包括零值。三名木匠死于恶性间皮瘤。其他死因，包括肺癌…然而，更多的NCER没有显示出SMR增加。这些结果与我们之前研究中接触石棉的落后者的结果形成了鲜明对比，这些落后者比木匠暴露的石棉要高得多。落后者显示肺癌的SMR增加了3.2，但没有死于间皮瘤。这些矿工从入职之日起一直被跟踪，直到1998年12月31日。140名男性中的127名和57名女性中的55名被成功识别。77名男性死亡。其中11人死于肺癌。JOB的亚队列分析显示，一个矿山的34名炼油厂中有8名死于癌症，这一事件与SMR的19(99%C.I.：6.9-44.9)相对应。精炼厂提炼毒砂，收集粉状砷，平均5年内砷暴露严重。女工未发现任何疾病的SMR升高。本研究结果表明，与砷相比，石棉对肺癌的致癌性较低，低剂量接触石棉可导致恶性间皮瘤，而不是肺癌。较少

Two historical cohort studies were conducted to investigate the effect of low dose asbestos exposure on mortality in occupational settings. One cohort consisted of 153 male carpenters worked as of 1976 in a shipyard. They had been exposed to asbestos intermittently for a short period when building rooms in a ship. The other cohort enrolled 199 workers (140 males and 59 females) in an arsenopyrite mine employed at some time between 1946 and 1958, the cohort which was set for a 'positive' control group to compare the magnitude of carcinogenecity between asbestos and arsenic. The carpenters were followed from 1976 to May 31, 1999 and 145 of the 153 study subjects were identified. 20 of them had died. The SMR of overall deaths, adjusted to the mortality in 5-year age and calendar year in a 5-year period in general Japanese populations, was 1.2, whose 95 % confidence interval included the null value. Three carpenters died from malignant mesothelioma. Other causes of death, including lung ca … More ncer, did not show increased SMRs, however. These results contrasted with those among the laggers exposed to asbestos much higher than the carpenters in our previous study. The laggers showed an increased SMR of 3.2 of lung cancer but no death from mesothelioma. The miners were followed from the date of employment till Dec 31, 1998. A total of 127 of 140 males and 55 of 57 females were successfully identified. 77 males had died. Of them 11 died form lung cancer. Subcohort analysis by job revealed that eight of 34 refiners in a mine died form the cancer and this occurrence corresponded to the SMR of 19 (99 % C.I. : 6.9-44.9). The refiners refined arsenopyrite ores and collected powdered arsenic, and accordingly were exposed arsenic heavily for five years in average. No elevated SMRs of any diseases were obtained in the female workers. The present results indicated that asbestos might have a lower carcinogenecity for lung cancer compared with arsenic, and that low dose exposure of asbestos could develop malignant mesothelioma rather than lung cancer. Less