This study investigated the toxic effects of benzene on the liver and kidney functions, complete blood picture, immunoglobulins and some antioxidant enzymes with emphasis of urinary trans, trans-muconic acid (t, t-MA)as a biomarker of benzene exposure, considering the influence of cigarette smoke. Eighty one workers (61 males and 20 females) have been exposed to benzene, while 83 subjects (55males and 28 females) represent a control group were also included. Blood samples were taken for the determination of alanine aminotransferase (ALT), asparatate aminotransferate (AST), Gamma glutamyl...