Liddell F D, McDonald A D, McDonald J C
Department of Epidemiology and Biostatistics, McGill University Montreal, Canada.
Ann Occup Hyg. 1997 Jan;41(1):13-36. doi: 10.1016/S0003-4878(96)00044-0.
This paper draws together the mortality experience for a cohort of some 11000 male Quebec Chrysotile miners and millers, reported at intervals since 1971 and now again updated. Of the 10918 men in the complete cohort, 1138 were lost to view, almost all never traced after employment of only a month or two before 1935; the other 9780 men were traced into 1992. Of these, 8009 (82%) are known to have died: 657 from lung cancer, 38 from mesotheliona, 1205 from other malignant disease, 108 from pneumoconiosis and 561 from other non-malignant respiratory diseases (excluding tuberculosis). After early fluctuations. SMRs (all causes) against Quebec rates have been reasonably steady since about 1945. For men first employed in Asbestos, mine or factory, they were very much what might have been expected for a blue collar population without any hazardous exposure. SMRs in the Thetford Mines area were almost 8% higher, but in line with anecdotal evidence concerning socio-economic status. At exposures below 300 (million particles per cubic foot) x years, (mpcf.y), equivalent to roughly 1000 (fibres/ml) x years-or, say, 10 years in the 1940s at 80 (fibres/ml)-findings were as follows. There were no discernible associations of degree of exposure and SMRs, whether for all causes of death or for all the specific cancer sites examined. The average SMRs were 1.07 (all causes), and 1.16, 0.93, 1.03 and 1.21, respectively, for gastric, other abdominal, laryngeal and lung cancer. Men whose exposures were less then 300 mpcf.y suffered almost one-half of the 146 deaths from pneumoconiosis or mesothelioma; the elimination of these two causes would have reduced these men's SMR (all causes) from 1.07 to approximately 1.06. Thus it is concluded from the viewpoint of mortality that exposure in this industry to less than 300 mpcf.y has been essentially innocuous, although there was a small risk or pneumoconiosis or mesothelioma. Higher exposures have, however, led to excesses, increasing with degree of exposure, of mortality from all causes, and from lung cancer and stomach cancer, but such exposures, of at least 300 mpcf.y, are several orders of magnitude more severe than any that have been seen for many years. The effects of cigarette smoking were much more deleterious than those of dust exposure, not only for lung cancer (the SMR for smokers of 20+ cigarettes a day being 4.6 times higher than that for non-smokers), but also for stomach cancer (2.0 times higher), laryngeal cancer (2.9 times higher), and-most importantly-for all causes (1.6 times higher).
本文汇总了约11000名魁北克温石棉矿工和磨工队列的死亡情况，自1971年起定期报告，现再次更新。在完整队列的10918名男性中，1138人失访，几乎所有人在1935年之前仅工作一两个月后就再也没有踪迹；其余9780名男性追踪至1992年。其中，已知8009人（82%）死亡：657人死于肺癌，38人死于间皮瘤，1205人死于其他恶性疾病，108人死于尘肺病，561人死于其他非恶性呼吸道疾病（不包括结核病）。经过早期波动后，自1945年左右起，与魁北克省死亡率相比的标准化死亡比（SMR，全因）一直相当稳定。对于首次在石棉矿或工厂工作的男性，其情况与没有任何有害暴露的蓝领人群预期的情况非常相似。塞特福德矿区的SMR几乎高出8%，但与关于社会经济地位的传闻证据相符。在暴露水平低于300（每立方英尺百万颗粒）×年（mpcf.y），相当于大约1000（纤维/毫升）×年——或者说，在20世纪40年代以80（纤维/毫升）的水平暴露10年的情况下，结果如下。无论是对于所有死因还是对于所检查的所有特定癌症部位，均未发现暴露程度与SMR之间存在明显关联。平均SMR（全因）为1.07，胃癌、其他腹部癌症、喉癌和肺癌的SMR分别为1.16、0.93、1.03和1.21。暴露水平低于300 mpcf.y的男性，尘肺病或间皮瘤导致的146例死亡中，他们几乎占了一半；消除这两个死因会使这些男性的SMR（全因）从1.07降至约1.06。因此，从死亡率的角度得出结论，该行业中低于300 mpcf.y的暴露基本上是无害的，尽管存在患尘肺病或间皮瘤的小风险。然而，更高的暴露导致全因死亡率、肺癌和胃癌死亡率过高，且随暴露程度增加，而至少300 mpcf.y的这种暴露比多年来所见到的任何暴露都严重几个数量级。吸烟的影响比粉尘暴露的影响更具危害性，不仅对于肺癌（每天吸20支及以上香烟者的SMR比不吸烟者高4.6倍）如此，对于胃癌（高2.0倍）、喉癌（高2.9倍），以及最重要的是对于全因（高1.6倍）也是如此。
