Methods: 68 coke oven workers were chosed as exposing group and 30 health people without any occupational exposure history of carcinogen were chosed as the control group.

方法：以炼焦工人68例为接触组，无任何职业致癌物接触史的健康体检者30例为对照组。

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Methods Retrospective epidemiological cohort study and field survey were conducted for dermatological examination, occupational hygiene and occupational exposure history for 2 876 workers.

方法采用现况调查和回顾性队列研究方法，对2 876名队列成员进行皮肤科检查和现场职业卫生学及个人职业史的调查。

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These are cases in which a worker is infected with HIV and has a history of occupational exposure, but did not have a test immediately before and after the possible exposure.

以下是某些具有职业接触史，并感染了HIV病毒的工作人员的病例，但他们在可能受感染的接触之前和之后都没有立即进行检测。

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