Blair A, Hartge P, Stewart P A, McAdams M, Lubin J
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892-7364, USA.
Occup Environ Med. 1998 Mar;55(3):161-71. doi: 10.1136/oem.55.3.161.
To extend the follow up of a cohort of 14,457 aircraft maintenance workers to the end of 1990 to evaluate cancer risks from potential exposure to trichloroethylene and other chemicals.
The cohort comprised civilians employed for at least one year between 1952 and 1956, of whom 5727 had died by 31 December 1990. Analyses compared the mortality of the cohort with the general population of Utah and the mortality and cancer incidence of exposed workers with those unexposed to chemicals, while adjusting for age, sex and calendar time.
In the combined follow up period (1952-90), mortality from all causes and all cancer was close to expected (standardised mortality ratios (SMRs) 97 and 96, respectively). Significant excesses occurred for ischaemic heart disease (SMR 108), asthma (SMR 160), and cancer of the bone (SMR 227), whereas significant deficits occurred for cerebrovascular disease (SMR 88), accidents (SMR 70), and cancer of the central nervous system (SMR 64). Workers exposed to trichloroethylene showed non-significant excesses for non-Hodgkin's lymphoma (relative risk (RR) 2.0), and cancers of the oesophagus (RR 5.6), colon (RR 1.4), primary liver (RR 1.7), breast (RR 1.8), cervix (RR 1.8), kidney (RR 1.6), and bone (RR 2.1). None of these cancers showed an exposure-response gradient and RRs among workers exposed to other chemicals but not trichloroethylene often had RRs as large as workers exposed to trichloroethylene. Workers exposed to solvents other than trichloroethylene had slightly increased mortality from asthma, non-Hodgkin's lymphoma, multiple myeloma, and breast cancer.
These findings do not strongly support a causal link with trichloroethylene because the associations were not significant, not clearly dose-related, and inconsistent between men and women. Because findings from experimental investigations and other epidemiological studies on solvents other than trichloroethylene provide some biological plausibility, the suggested links between these chemicals and non-Hodgkin's lymphoma, multiple myeloma, and breast cancer found here deserve further attention. Although this extended follow up cannot rule out a connection between exposures to solvents and some diseases, it seems clear that these workers have not experienced a major increase in cancer mortality or cancer incidence.
对14457名飞机维修工人队列进行随访至1990年底，以评估潜在接触三氯乙烯和其他化学物质所致的癌症风险。
该队列包括1952年至1956年间受雇至少一年的平民，到1990年12月31日已有5727人死亡。分析比较了该队列与犹他州普通人群的死亡率，以及接触化学物质的工人与未接触化学物质的工人的死亡率和癌症发病率，同时对年龄、性别和日历时间进行了调整。
在联合随访期（1952 - 90年），所有原因和所有癌症的死亡率接近预期（标准化死亡率分别为97和96）。缺血性心脏病（标准化死亡率108）、哮喘（标准化死亡率160）和骨癌（标准化死亡率227）出现显著超额，而脑血管疾病（标准化死亡率88）、事故（标准化死亡率70）和中枢神经系统癌症（标准化死亡率64）出现显著不足。接触三氯乙烯的工人非霍奇金淋巴瘤（相对危险度2.0）、食管癌（相对危险度5.6）、结肠癌（相对危险度1.4）、原发性肝癌（相对危险度1.7）、乳腺癌（相对危险度1.8）、宫颈癌（相对危险度1.8）、肾癌（相对危险度1.6）和骨癌（相对危险度2.1）有非显著超额。这些癌症均未显示出暴露 - 反应梯度，且接触其他化学物质但未接触三氯乙烯的工人的相对危险度往往与接触三氯乙烯的工人一样高。接触三氯乙烯以外溶剂的工人哮喘、非霍奇金淋巴瘤、多发性骨髓瘤和乳腺癌的死亡率略有增加。
这些发现并不强烈支持与三氯乙烯存在因果联系，因为这些关联不显著、无明显剂量关系且男女之间不一致。由于对三氯乙烯以外溶剂的实验研究和其他流行病学研究结果提供了一些生物学合理性，此处发现的这些化学物质与非霍奇金淋巴瘤、多发性骨髓瘤和乳腺癌之间的潜在联系值得进一步关注。尽管此次延长随访不能排除接触溶剂与某些疾病之间的关联，但显然这些工人的癌症死亡率或癌症发病率并未大幅上升。
