Ward E, Carpenter A, Markowitz S, Roberts D, Halperin W
Industrywide Studies Branch, National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226.
J Natl Cancer Inst. 1991 Apr 3;83(7):501-6. doi: 10.1093/jnci/83.7.501.
A retrospective cohort study of the incidence of bladder cancer was conducted in response to a union request for an evaluation of a possible excess number of cases of bladder cancer at a chemical plant in western New York State. Workers at the plant were exposed to two potential bladder carcinogens--ortho-toluidine (o-toluidine) and aniline. Incidence rates of bladder cancer among workers at the plant were compared with those of the population of New York State (excluding New York City). Among all 1749 workers at the plant, 13 cases of bladder cancer were observed versus 3.61 expected [standardized incidence ratio (SIR) = 3.60; 90% confidence interval (CI) = 2.13-5.73]. Among the 708 workers who worked in areas in which o-toluidine and aniline were used, 7 cases were observed versus 1.08 expected (SIR = 6.48; 90% CI = 3.04-12.2). Among the 288 maintenance, shipping, and janitorial workers thought to have been possibly exposed, 4 cases were observed versus 1.09 expected (SIR = 3.66; 90% CI = 1.25-8.37). Among the remaining 753 workers who were probably not exposed, 2 bladder cancers were observed versus 1.43 expected (SIR = 1.39; 90% CI = 0.25-4.39). Increased risk of bladder cancer was strongly associated with increased duration of employment in the department where o-toluidine and aniline were used (P less than .001). Among workers with 10 or more years of employment in the department, the SIR was 27.2 (90% CI = 11.8-53.7). o-Toluidine is an animal carcinogen more potent than aniline and is known to produce bladder tumors in rats; hence, it is more likely that o-toluidine is responsible for the observed excess number of cases of bladder cancer, although aniline may have played a role.
应工会要求，对纽约州西部一家化工厂膀胱癌发病情况是否可能异常增多进行评估，开展了一项膀胱癌发病率的回顾性队列研究。该厂工人接触两种潜在的膀胱致癌物——邻甲苯胺和苯胺。将该厂工人的膀胱癌发病率与纽约州（不包括纽约市）人口的发病率进行了比较。在该厂全部1749名工人中，观察到13例膀胱癌，而预期为3.61例[标准化发病比（SIR）=3.60；90%置信区间（CI）=2.13 - 5.73]。在使用邻甲苯胺和苯胺的区域工作的708名工人中，观察到7例，而预期为1.08例（SIR = 6.48；90% CI = 3.04 - 12.2）。在288名被认为可能接触过的维修、运输和保洁工人中，观察到4例，而预期为1.09例（SIR = 3.66；90% CI = 1.25 - 8.37）。在其余可能未接触过的753名工人中，观察到2例膀胱癌，而预期为1.43例（SIR = 1.39；90% CI = 0.25 - 4.39）。膀胱癌风险增加与在使用邻甲苯胺和苯胺的部门工作时间延长密切相关（P < 0.001）。在该部门工作10年或更长时间的工人中，SIR为27.2（90% CI = 11.8 - 53.7）。邻甲苯胺是一种比苯胺更强的动物致癌物，已知可在大鼠中诱发膀胱肿瘤；因此，虽然苯胺可能也起了一定作用，但观察到的膀胱癌病例异常增多更有可能是由邻甲苯胺导致的。
