Distribution, Source finding, ecological hazard assessment and water-sediment exchange rate of polychlorinated biphenyl compounds (PCBs) in South Pars Industrial Zone, Iran

Abstract South Pars Industrial Zone is located near an Assaluyeh city on the coast of the Persian Gulf and is known as the energy capital of Iran. In this study, environmental and health effects due to PCB components had an assessment. In this study, 10 air stations, 10 seawater, and sediments stations were systematically selected and sampled in two seasons. Air, seawater and sediment pollution made by polychlorinated biphenyls (PCBs) were evaluated. Seawater-sediment exchange conditions using the fugacity coefficient reviewed. PCB levels in marine sediments, seawater, and air-based on the analysis of the obtained data were 107.33-172.92 ng / g, ND-135.68 μg / l, and ND-4.4 ng / m3, respectively. The highest concentration was observed in the vicinity of refineries, petrochemicals, and petroleum export facilities. These values had increased significantly compared to values of studies, conducted in similar areas. The sources were electrical wastes, storage sites, power generation units, and wastewater treatment. The ecological risk of seawater was assessed to be high, while sediment risks were reported with a low to moderate risk range. The heavier compounds with more chlorine were moved from sediments to seawater and, showed that seabed acted as a secondary source of sea pollution. Lighter compounds with less chlorine moved toward the sediments, from the seawater, and the seabed acted as a sink for these compounds. It is suggested for the area to be continuously monitored while engineering and management measures should be adopted to improve the situation and also prevent the spread of pollution.