有些职业经常接触到的某些物质是能引起肿瘤的,这类物质在医学上称为职业性致癌物质。到目前为止,已经确认的职业性致癌物质有20多种。因职业关系接触这类物质所致的肿瘤,即是职业性肿瘤。 Some occupations often come into contact with certain substances that can cause tumors, these substances are medically known as occupational carcinogens. So far, more than 20 types of occupational carcinogens have been identified. Due to occupational exposure to such substances caused by the tumor, that is, occupational tumors.