[Horizontal and vertical distribution of polybrominated diphenyl ethers (PBDEs) in river sediment from a typical electrical equipment industrial area].

Polybrominated diphenyl ethers (PBDEs) were determined in sediment collected from a river in a typical electrical equipment industrial area, Ronggui, Foshan. Eight samples were collected from river sediment. The results indicated that PBDEs were presented in all samples. Spatial trends showed that the concentrations of PBDEs in all sediment samples were ranged from 62 ng x g(-1) to 349 ng x g(-1), with an average of 178 ng x g(-1). The predominant congener was BDE-209 (90% - 99%), which ranged from 56-337 ng x g(-1), with an average of 171 ng x g(-1). Some of congeners such as BDE-196, 197 and 203 may be were the degradation product of BDE-209. Vertically, the concentrations of PBDEs were increased with the depth, whereas the concentrations were 147 ng x g(-1) in layer 0-10 cm and 260 ng x g(-1) in layer 30-40 cm, respectively. Distribution profile of PBDEs in vertical direction was similar in different depths. The commercial deca-BDE (94%), which contained BDE-209, 208, 207 and 206, was the dominate pollutant with minor contributions from penta-and octa-BDEs. The results suggested that this area was polluted by PBDEs and BDE-209 was the most dominate congener, which is related with the manufacturing activities for electrical equipment.

[Distribution and potential ecological risk of polycyclic aromatic hydrocarbons in the sediments from typical electronics industrial zone].

In order to investigate the polycyclic aromatic hydrocarbons (PAHs) contamination status in a river of a typical electrical equipment industrial area, Ronggui, Foshan, 8 sediments simples were collected. The results showed that 12 components of PAHs were detected in all sediment samples, and the other 4 components were also detected in different degree. The total 16 EPA priority PAHs contents in surface sediments varied from 343.5 microg x kg(-1) to 2 099 microg x kg(-1) (dry wt), with an average of 1215.9 microg x kg(-1), and no significant variation was found in vertical distribution. The 2 to 3 aromatic rings were the dominant PAHs, and they accounted for 50.69% to 82.5% of the total PAHs. Diagnostic ratios were used to identify the possible sources of PAHs, and the results indicated that PAHs were mainly pyrogenic origin. Sediments were polluted by PAHs heavily according to Maliszewska-Kordybach's standard, the very high risk level was also confirmed by the contamination factors assessment which was investigated by comparison with the background area (SO). The assessment by the method of sediment quality guidelines (SQGs) and relative contamination factor (RCF) demonstrated that adverse biological toxicity effect might occasionally happen in a few sampling sites, and the ecological risk components included acenaphthene (Ace), fluorine (Flu), and phenanthrene (Phe).