Persistent organochlorine residues in marine and freshwater fish in Cambodia

Concentrations of persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDT compounds (DDTs), HCH (hexachlorocyclohexanes) isomers (HCHs), chlordane compounds (CHLs) and HCB (hexachlorobenzene) were determined in 27 species of marine and freshwater fish collected from Cambodia. DDT and its derivatives mere the predominantly detected compounds in both marine and freshwater fish. PCBs were the second highest followed by HCHs, CHLs and HCB. Freshwater fish contained higher concentrations of DDTs than those of marine fish, implying that the sources of DDTs originate from inland watersheds such as the Mekong River, Basac River, Tonlesap River and Tonlesap Great Lake. Comparison of the OCs residue levels in Cambodian fish with those in other Asian and Oceanic regions suggested that Cambodia is one of the less-contaminated countries by OCs. In other words, it can be concluded that Cambodia has kept "Clean Environment" among Asian and Oceanic countries. (C) 1999 Elsevier Science Ltd. All rights reserved.