联苯胺及其同类物的偶氮染料和颜料广泛应用于食品、药品、化妆品、纺织、印刷、造纸、皮革及塑料等工业,是一类重要的环境化合物。流行病学研究表明染料工业工人膀胱肿瘤的发病率高于一般人群.不少偶氮染料是实验动物的致癌物,如直接兰6、直接黑38以及直接棕95对大鼠有致癌作用。偶氮化合物被哺乳动物和人经口摄入后可被肠道厌氧菌群还原,同时可能被肠壁细胞或肝脏中的偶氮还原酶还原而释放出芳香 Benzidine and its azo dyes and pigments are widely used in food, medicine, cosmetics, textile, printing, paper making, leather and plastics industries. They are an important class of environmental compounds. Epidemiological studies have shown that the incidence of bladder cancer in dye industrial workers is higher than that in the general population.Many azo dyes are carcinogens in laboratory animals, such as direct blue 6, direct black 38 and direct brown 95 on rats. Azo compounds by mammalian and human oral intake of intestinal anaerobic bacteria can be reduced at the same time may be intestinal cells or liver azo reductase to release the release of aromatic