AQUATIC PREDICTED NO-EFFECT CONCENTRATIONS OF 16 POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR ECOLOGICAL RISKS IN SURFACE SEAWATER OF LIAODONG BAY, CHINA

Polycyclic aromatic hydrocarbons (PAHs), a class of ubiquitous pollutants in marine environments, exhibit moderate to high adverse effects on aquatic organisms and humans. However, the lack of PAH toxicity data for aquatic organism has limited evaluation of their ecological risks. In the present study, aquatic predicted no-effect concentrations (PNECs) of 16 priority PAHs were derived based on species sensitivity distribution models, and their probabilistic ecological risks in seawater of Liaodong Bay, Bohai Sea, China, were assessed. A quantitative structure-activity relationship method was adopted to achieve the predicted chronic toxicity data for the PNEC derivation. Good agreement for aquatic PNECs of 8 PAHs based on predicted and experimental chronic toxicity data was observed (R-2 = 0.746), and the calculated PNECs ranged from 0.011 mg/L to 205.3 mg/L. Asignificant log-linear relationship also existed between the octanol-water partition coefficient and PNECs derived from experimental toxicity data (R-2 = 0.757). A similar order of ecological risks for the 16 PAH species in seawater of Liaodong Bay was found by probabilistic risk quotient and joint probability curve methods. The individual high ecological risk of benzo[a]pyrene, benzo[b]fluoranthene, and benz[a]anthracene needs to be determined. The combined ecological risk of PAHs in seawater of Liaodong Bay calculated by the joint probability curve method was 13.9%, indicating a high risk as a result of co-exposure to PAHs. (C) 2015 SETAC