Department of Preventive Medicine and Public Health, Keio University School of Medicine.
Department of Public Health, School of Human Life Sciences, Jumonji University.
J Occup Health. 2018 Jul 25;60(4):307-311. doi: 10.1539/joh.2017-0220-OA. Epub 2018 May 9.
ortho-Toluidine (OT) was listed as a Group 1 carcinogen by the International Agency for Research on Cancer in 2012 based on epidemiological observations of workers co-exposed to OT and aromatic amines. From 2014 to 2017, several cases of bladder cancer (BCa) secondary to occupational exposure, primarily to OT, were detected in Japan.
To describe 10 cases of BCa in male Japanese workers exposed primarily to OT at two plants that produce organic dye and pigment intermediates.
Details of the 10 cases were obtained from company records and through a questionnaire and interview. The surrogate level of exposure to each aromatic amine was calculated as the total job-weight/month for each process for each job-year.
No quantitative exposure data were available. In most cases the surrogate level of exposure to OT was higher than to other amines. All 10 cases were exposed primarily to OT and co-exposed to para-toluidine, ortho-anisidine, aniline, 2,4-xylidine or ortho-chloroaniline. The age range at diagnosis was 41-71 years (mean 56). The duration of OT exposure was 7-28 years (mean 16.5). Disease latency was 16-28 years (mean 21.9). Eight patients were smokers. The main symptom at diagnosis was hematuria (70%).
The characteristics of BCa cases were associated with a high surrogate level of OT exposure and a disease latency of more than 20 years from the initial OT exposure. The main route of OT exposure was likely through the skin. It is necessary to continue health examinations in these target groups.
国际癌症研究机构（IARC）于 2012 年将邻甲苯胺（OT）列为 1 类致癌物质，这是基于对同时接触 OT 和芳香胺的工人进行的流行病学观察。2014 年至 2017 年期间，日本发现了几起因职业暴露主要是 OT 引起的膀胱癌（BCa）病例。
描述在生产有机染料和颜料中间体的两家工厂中，主要暴露于 OT 的 10 例日本男性工人的膀胱癌病例。
通过公司记录以及问卷调查和访谈获得了这 10 例病例的详细信息。每个芳香胺的暴露替代水平计算为每个工作年每个过程的总工作重量/月。
没有定量暴露数据。在大多数情况下，OT 的暴露替代水平高于其他胺。所有 10 例病例主要暴露于 OT，并同时接触对甲苯胺、邻甲氧基苯胺、苯胺、2,4-二甲氧基甲苯或邻氯苯胺。诊断时的年龄范围为 41-71 岁（平均 56 岁）。OT 暴露的持续时间为 7-28 年（平均 16.5 年）。疾病潜伏期为 16-28 年（平均 21.9 年）。8 名患者为吸烟者。诊断时的主要症状是血尿（70%）。
膀胱癌病例的特征与 OT 暴露的高替代水平和从最初的 OT 暴露到发病的潜伏期超过 20 年有关。OT 暴露的主要途径可能是通过皮肤。有必要在这些目标群体中继续进行健康检查。
