PCBs, PBDEs, PCDD/Fs, chlorinated pesticides and hydrocarbons in soils and sediments from the Bac Giang Province and the Cau River (northern Vietnam)

Persistent organic pollutants (POPs) such as PCBs, PBDEs, PCDD/Fs together with chlorinated pesticides and hydrocarbons (C>12) were analysed in 30 soil and sediment samples taken from different environments in the southwestern Bac Giang province. In general, PCBs are quite low, whereas PBDEs, excepting the congener 209, were relatively high and certainly underestimated. Chlorinated pesticide concentrations were below detection limits (e.g., 1.0 ?g kg-1 for DDE), whereas hydrocarbons are low, except the maximum value (54.7 mg kg-1) in the sediment in front of a sewage that exceeded the Italian law limit for urban soils. The composition of the mixtures provides some important information. The main component of PCDDF, that greatly exceeds the others, is octa-dioxin that originates from combustion.