Organochlorine pesticides and PCBs along the coast of north Vietnam

Organochlorine pesticides and polychlorinated biphenyls (PCBs) were determi ned in sediments and clams collected from the coast of the north of Vietnam during the rainy season (August-September 1997). Results show that the org anochlorine pesticides of major concern are HCHs (1.2-33.7 ng g(-1) dry wt. ), DDTs (6.2-10.4 ng g(-1) dry wt.) and HCB (0.1-6.5 ng g(-1) dry wt.). PCB s, in aroclor 1254 equivalents, were also generally present in concentratio ns ranging from 0.47 to 28.1 ng g(-1) sediment dry wt. Concentrations measu red in the soft tissues of clams (Meretrix meretrix) generally reflect the level of contamination at the Sampling sites. In the clams, the concentrati ons of DDTs (12.0-23.3 ng g(-1) dry wt.) and PCBs (5.1-25.3 ng g(-1) dry wt .) were generally higher than those of other chlorinated hydrocarbons. Thes e results underscore the need to improved environmental protection measures in order to reduce the exposure of the population to these persistent and bioaccumulative compounds through food ingestion. (C) 1999 Elsevier Science B.V. All rights reserved.