Ambient concentrations of polychlorinated biphenyls and organochlorine pesticides in selected Thai estuarine sediments and mussels

Abstract

Over the past few decades, the occurrence of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the environment is of great concern due to their persistent and long-range transportable nature as well as toxic biological effects. While most of developed countries have already banned or restricted the production and usage of these compounds, some developing countries still use OCPs for agricultural and the public health purposes. This paper presents data on the concentrations of PCBs and OCPs in selected Thai estuarine sediments and mussels. A total of 20 composite sediment samples and 10 composite mussel samples were collected from two estuaries draining to the inner Gulf of Thailand, namely the Thachin and Bangpakong estuary in 2004. Aldrin, dieldrin, endrin, and heptachlor were not detected in either the mussels or sediments from both study sites. The most frequently detected pesticides were DDTs and chlordanes (CHLs), with relatively low concentration of hexachlorocyclohexanes (HCHs). Low concentrations of PCBs were only detected in sediment and mussel samples from the Bangpakong estuary, with penta-, hexa- and hepta-chlorinated congeners are the dominant homologues. The results from this study demonstrate that ambient concentrations of PCBs and OCPs in Thai estuaries are low, and in most cases lower than concentrations reported for estuaries in many Asian countries.Proceedings of 4th JSPS-VAST Joint Seminar on \u27Coastal Marine Science\u27, Hai Phong, Viet Nam, 26-28 October 2009Ocean Pollutio