**Abstract**

Benzo[a]pyrene (B[a]P) is a major polycyclic aromatic hydrocarbon (PAH), it can bind the DNA to produce DNA-adducts, which has major carcinogenic potential. Enzyme-linked immunosorbet assay (ELISA) is the method used to detect these DNA adducts of B[a] P diolepoxide (BPDE) within the living cells. The aim of this study is to evaluate exposure to bitumen fumes, and to B[a]P in asphalt plant workers by measuring the BPDE-DNA adducts in their peripheral white blood cells (WBC), which are considered biological markers for exposure risk assessment. In this study, Hemostatic blood (CBC, AST) were measured, and the levels of BPDE-DNA adducts were measured in DNA samples of WBC obtained from asphalt plant workers in Syria and compared to those measured from a control group. The measurement was performed using BPDE-DNA Adducts ELISA.kit. The sample size was determined to be 50 with 25 asphalt plant workers and 25 healthy volunteers with no occupational exposure to PAHs. The results showed some diseases associated with exposure to asphalt fumes among the workers in the study group and a statistically significant difference in the values of (CBC; WBC, leukocytes, HCT, MCHC and AST) between the study group and the control group. BPDE-DNA adducts were detected in WBC of 11 asphalt plant workers with concentrations ranging between 0 and 2.75 ng/ml and only one individual in the control group with concentration of 0.75 ng/ml. These results indicate significant positive relationship between exposure to the bitumen fumes and formation of BPDE-DNA adducts. BPDE-DNA adducts is potential biomarker for PAHs exposure and likely helpful indicator of PAH-induced DNA damage and possibly carcinogenesis.

**Keywords:** benzo[a]pyrene, CBC, AST, BPDE-DNA adducts, asphalt workers
