Persistent organic pollutants (POPs) in intertidal surface sediments from the Yangtze estuarine and coastal areas, China

Persistent organic pollutants, including polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in surface sediments taken from intertidal flats in the Yangtze Estuary and coastal area were determined by GC-ECD and GC-MS. The results indicated that the PCB levels varied from 0.187-18.948 ng/g and 1.245-36.009 ng/g for OCPs. Total PAH concentration ranged from 0.263-6.372 ng/g with an average of 1.662 ng/g from the study area. The concentration levels of POPs varied dramatically between different areas. They are characterized by near sewage discharge maxima, followed by decreased levels among the sites where there are no obvious sources of effluent discharges. Moreover, the degree of sediment contamination by PCBs and OCPs in the study area is lower than the effects range-low (ER-L) values, indicating that adverse biological effects were not obviously present. PAH compounds such as anthracene and fluorine, however, exceed the ER-L values, showing a primary potential impact for the Yangtze estuarine tidal flat ecosystem.