Dechlorane Plus in Surficial Water and Sediment in a Northeastern Chinese River

Surface water and sediment samples concurrently collected in Songhua River in northeastern China from May to October 2006 were analyzed for Dechlorane Plus (DP), a chlorinated flame retardant. Samples were obtained from three main areas: SHR-Rul (rural area of Songhua River), SHR-Hrb (the section of the river within the city of Harbin), and Hrb (urban waters of Harbin). The majority of SHR-Rul water samples (85%) and SHR-Hrb water samples (73%) and 33% of urban water samples (Hrb) were below the detection limit. The mean water DP concentration in Hrb (0.55 ± 0.81 ng L−1) was approximately 3 times greater than the levels measured in SHR-Hrb (0.17 ± 0.38 ng L−1) and more than 15 times greater than the levels measured in SHR-Rul (0.03 ± 0.07 ng L−1). DP detection rates in sediment samples were 50% (Hrb), 100% (SHR-Hrb), and 78% (SHR-Rul). The mean sediment DP concentration in SHR-Hrb (0.11 ± 0.05 ng g−1) was approximately three times greater than that in SHR-Rul (0.04 ± 0.05 ng g−1). These DP concentrations are likely attributable to local sources in urban areas rather than distant sources via long-range transport. The mean fractional abundance of the syn isomer of DP (fsyn) was 0.34 ± 0.10 in all water samples, a value indistinguishable from that of a commercial mixture (fsyn = 0.35), indicating the source was local. The mean fsyn value of 0.23 ± 0.06 in all sediment samples suggested a stereoselective depletion of syn-DP relative to the anti-DP isomer in sediments. To our knowledge, this paper represents the first report of DP concentrations in Chinese water and sediments.