SPATIAL DISTRIBUTION AND ECOLOGICAL RISK ASSESSMENT OF NONYLPHENOL IN SEDIMENTS FROM YANGTZE ESTUARY AND ITS ADJACENT AREA

The distribution patterns of nonylphenol (NP) were surveyed in 26 surface sediments and one sediment core collected from Yangtze Estuary and its adjacent area from May to June of 2010. In the surface sediments, NP concentrations first increased and then decreased from inshore to offshore, ranging from 137.5 ng/g dry weight (d.w.) to 559.0 ng/g d.w. High values of NP were found in coastal mud areas. The spatial distribution of NPwas influenced by Yangtze River runoff and other water currents controlling sediment transport. In the core sample, NP concentrations decreased with increasing depth, indicating more serious NP pollution from 2000 to 2010. Overall, the NP contamination level in this area was at the medium level, when compared with those of other estuaries and bays. However, the high risk quotient values of NP that ranged from 3.5 to 14.3 in all the stations suggested a significant risk for sediment biota.