PBDD/Fs in surface sediments from the East River, China.

The contamination status of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) was preliminarily investigated in surface sediments from the East River. The concentrations of eight 2,3,7,8-substituted tetra- to hexa- PBDD/Fs were found to be in the range of 0.32-110 (mean 13) pg g(-1) and the corresponding TEQ concentrations were 0.087-18 (mean 2) pg I-TEQ g(-1). All sediments were characterized by the dominant PBDFs. 2,3,4,7,8-PeBDF was the most important TEQ contributor, accounting for 47%-77% of the total I-TEQ of PBDD/Fs. PCDD/Fs contributed dominantly to the total TEQs of PCDD/Fs, PBDD/Fs and dioxin-like PCBs in most samples except of the sediment from the Shima River. The higher PBDD/F concentrations in the Shima River may be attributed to the use of BFRs in the electrical and electronics industries, which posed a potential risk of dioxins on ecological system.