目前,化工系统正在对接触多环芳烃、联苯胺、氯甲醚、砷,铬、橡胶加工、氯乙稀等七种致癌物质(工业过程)的作业职工进行职业性肿瘤调查。实地调查完成后,调查资料要进行统计分析。统计分析时,很少用患病和死亡的实数,而常用一些率,如发病率、患病率、病死率、死亡率等。所谓率,是一个分数,在调查资料的统计分析中,这个分数的分子是观察期间内事例发生 At present, the chemical system is conducting occupational cancer investigations among workers in contact with PAHs, benzidine, chloromethyl ether, arsenic, chromium, rubber processing, chlorine and ethyl carcinogens (industrial processes). After the field survey is completed, the survey data should be statistically analyzed. In statistical analysis, the real numbers of illnesses and deaths are seldom used, and some commonly used rates such as morbidity, prevalence, fatality rate and mortality are often used. The so-called rate, is a score, in the statistical analysis of survey data, the numerator of this score is the occurrence of cases during the observation period