Concentration, distribution, and risk assessment of polychlorinated biphenyl compounds in surface sediments of the Persian Gulf and the Oman Sea

This study involved analyzing 76 sediment samples from the Persian Gulf and Oman Sea. The concentration of 18 prevalent PCB congeners was determined. Results indicated that the highest concentration of PCB-52, reaching 636.1 pg/g dw, was found at the T11S3-2 station in the Oman Sea, while PCB-28 had a concentration of 139.0 pg/g dw at the T0S1 station in the Persian Gulf. Furthermore, the average concentration of PCB-28 was 114.5 pg/g dw, in conformity with other regional studies. The average PCB concentration was 12.8 pg/g dw in the Persian Gulf and 35.0 pg/g dw in the Oman Sea. Risk assessment based on ecological risk index (ERI) and sediment quality guidelines (SQGs) indicated that both regions fell within acceptable limits of PCB pollution, except for the T11S3-2 station in the Oman Sea, which was categorized as having a medium risk range due to a concentration of 636.1 pg/g dw. However, the average PCB concentration across all sampled stations consistently stays below the threshold for minimal risk. These values indicate concentrations that are relatively low compared to those found in numerous industrial and urban regions worldwide.