For example, there is an indication that occupational exposure to benzene causes significant alterations in hematological and biochemical parameters and workers are at high risk of developing blood, hepatic or renal related disorders , . Exposure to carcinogens is associated with different forms of DNA damage which includes single-stand breaks, double-strand breaks, covalently bound chemical DNA adducts, oxidative-induced lesions and DNA-DNA or DNA-protein cross-links .