引言肿瘤的病因有三: (A)环境因素:从流行病学调查资料可见,环境因素与肿瘤的发生关系密切。如东南亚及华南一带口腔癌和鼻咽癌较多,食用含亚硝胺化物的腌菜易诱发食道癌,污染黄曲霉的花生和玉米可诱发肝癌,工业污染如煤炭,水泥及吸烟与肺癌的关系,乙萘胺和联苯胺与职业性膀胱癌的关系,沥青可诱发皮肤赘生物或癌变。在动物实验方面,常可利用某些理化 Introduction The causes of cancer are three: (A) Environmental factors: From the epidemiological survey data shows that environmental factors and the occurrence of cancer are closely related. Such as Southeast Asia and South China more oral cancer and nasopharyngeal carcinoma, eating nitrosamines containing pickles easy to induce esophageal cancer, pollution of aflatoxin peanuts and corn can induce liver cancer, industrial pollution such as coal, cement and smoking and lung cancer Relationship, ethidium and benzidine and occupational bladder cancer, asphalt can induce skin neoplasm or cancer. In animal experiments, can often use some of the physical and chemical