[Vertical distribution of PBDEs and DL-PCBs in sediments of Taihu Lake].

Sediment core samples collected from the Zhushan Bay,Meiliang Bay,South Taihu of Taihu Lake were analyzed for 8 polybrominated diphenylethers(PBDEs) and 12 dioxin-like PCBs(DL-PCBs).The results revealed that the PBDEs levels were highest in the Zhushan Bay,followed by Meiliang Bay and South Taihu;and the DL-PCB levels were highest in the Meiliang Bay,followed Zhushan Bay and South Taihu.The vertical distribution of PBDEs level showed an exponential growth trend in Taihu Lake sediments,BDE-209 was the most abundant PBDEs congeners;and the vertical distribution of the DL-PCBs level in the sediments revealed that the contamination caused by DL-PCBs continued to increase in recent years,indicating that there were PCBs sources in the Taihu Lake region.There was significant difference in the composition of PBDEs congeners at different depths in the sediments of Meiliang Bay,however,the detailed causes remain to be investigated in further studies.The vertical distribution pattern of PCBs congeners revealed that PCB-77,-118,-105 levels significantly decreased with increasing depth in 0-15 cm upper sediments and there were no significant change in the lower sediments.