Organochlorine pesticides and PCBs along the coast of north Vietnam

Organochlorine pesticides and polychlorinated biphenyls PCBs. were determined in sediments and clams collected from the coast of the north of Vietnam during the rainy season August]September 1997.. Results show that the organochlorine pesticides of major concern are HCHs 1.2]33.7 ng gy1 dry wt.., DDTs 6.2]10.4 ng gy1 dry wt.. and HCB 0.1]6.5 ng gy1 dry wt... PCBs, in aroclor 1254 equivalents, were also generally present in concentrations ranging from 0.47 to 28.1 ng gy1 sediment dry wt. Concentrations measured in the soft tissues of clams (Meretrix meretrix. generally reflect the level of contamination at the sampling sites. In the clams, the concentrations of DDTs 12.0]23.3 ng gy1 dry wt.. and PCBs 5.1]25.3 ng gy1 dry wt.. were generally higher than those of other chlorinated hydrocarbons. These 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.