Organochlorine pesticide and polychlorinated biphenyl residues were determined in soils and
surface sediments collected from Hanoi City, Vlettri City and Halong Bay, which are representative of
industrial and agricultural areas in northern Vietnam. Polychlorinated biphenyls (PCBs) and organochlorine
insecticides such as DDT and its metabolites (DDTs) and lindane were detected in all samples analyzed,
indicating the widespread contamination by these compounds in the environment of the north of Vietnam.
Concentrations of DDTs and lindane were found to be highest in sediments from Halong Bay, followed by
those in Viettri and Hanoi. PCB residues ranged from 0.64 ng g-1 to 120 ng g-1 (dry weight basis) in
sediments and these levels were generally higher than those in soil samples. In general, higher
concentrations of pesticides and PCBs were recorded in Halong Bay, suggesting the local sources in this
area, probably from mining activities.
