砷是人类的确认致癌物。砷暴露可导致人类肺癌和皮肤癌，近期研究表明砷还可引起多种脏器癌症患病率增高［１］。但迄今为止，作为有着广泛生物学作用的砷的致癌机理，没有取得令人服信的进展。砷致癌的个体易感因素及实验动物模型仍属未知。砷在环境和生物机体中均有生物甲基 Arsenic is a human confirmed carcinogen. Arsenic exposure can lead to human lung and skin cancer, recent studies have shown that arsenic can also cause an increased prevalence of multiple organ cancers [1]. However, to date, no convincing progress has been made as a carcinogenic mechanism of arsenic with a wide range of biological properties. Susceptibility to arsenic carcinogens and experimental animal models remain unknown. Arsenic has biological methyl groups both in the environment and in living organisms