DISTRIBUTION CHARACTERISTICS AND ECOLOGICAL RISK ASSESSMENT OF NONYLPHENOL IN JIAOZHOU BAY IN QINGDAO, CHINA

Nonylphenol (NP) is an endocrine disruptor, and its environmental distribution and ecological risks have drawn widespread concerns. In this study, the distribution of NP was investigated in the waters of Jiaozhou Bay (JZB) in Qingdao, China in April 2007 and August 2009. The predicted no-effect concentration (PNEC) was calculated as the criterion for ecological risk assessment of NP based on the toxic experiments of NP on five dominant phytoplankton species in JZB (Skeletone macostatum, Chaetoceres curvisetus, Pseudonitzschia pungens, Dunaliella salina, and Platymonas helgolanidica). Results showed that the concentrations of NP in JZB ranged from 23.6 ng/l to 192.9 ng/l in April 2007 and from 18.5 ng/l to 179.3 ng/l in August 2009. High NP levels were observed in northeast and northwest JZB. The PNEC for NP in seawater was 79.0 ng/l, which was calculated using the EC50 value of C. curvisetus because of its higher sensitivity compared with the other algae species. The risk quotients of NP in the waters of JZB ranged from 0.23 to 2.44, with an average of 0.76, thereby implying a significant risk for aquatic ecosystems in some areas of JZB.