Re ECF Project: 2012-15

Project Title: Assessment of conventional, new persistent organic pollutants (POPs) and trace elements in Hong Kong cetaceans

Applicant: Dr. James Lam Chung-Wah, State Key Laboratory in Marine Pollution, City University of Hong Kong

Total Approved Grant: $986,240

Duration: 1/5/2014 to 30/4/2016

Project Status/Remarks: Completed

This project aimed to provide comprehensive information for prioritizing the risk and occurrence of a wide range of contaminants of concern in Hong Kong.

Summary of the Findings/Outcomes:
The investigation focused on the measurement of initial and new POPs listed under the Stockholm Convention as well as trace elements in the specimens of dolphins and porpoises stranded from Hong Kong waters. Results of chemical analyses indicated that the two dominant trace organics in the blubber samples from stranded cetaceans were PCBs and DDTs, and the new POPs such as brominated flame retardants and PFOS were also prevalent in the samples. The dominant trace elements found in the liver samples of both stranded cetacean species were Zn, followed by Cu/Hg. These differences in levels and contamination patterns were likely due to different dietary preferences and habitats of the two cetacean species. Probabilistic risk assessment was conducted and the outcome of the preliminary risk characterization demonstrated that there might be potential risks to cetaceans associated with long-term exposure to some of these environmental contaminants, but the risk of Cd to cetacean populations in Hong Kong was minimal. However, certain uncertainties existed in the risk assessment process. Overall, this study provided a comprehensive assessment of marine ecological risks for marine mammals in Hong Kong as well as a scientific basis to facilitate monitoring of pollutants in our marine ecosystem.