One century record of contamination by polycyclic aromatic hydrocarbonsand polychlorinated biphenyls in core sedimentsfrom the southern Yellow Sea
ZHANG Peng , SONG Jinming , FANG Jie , LIU Zhigang , LI Xuegang , YUAN Huamao
DOI:
Received October 07, 2008,Revised November 24, 2008, Accepted , Available online
Volume 21,2009,Pages 1080-1088
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Sixteen polycyclic aromatic hydrocarbons (PAHs) and 28 polychlorinated biphenyls (PCBs) were measured at a 2-cm interval in a
core sample from the middle of the southern Yellow Sea for elucidating their historical variations in inflow and sources. The chronology
was obtained using the 210Pb method. PAHs concentrations decreased generally with depth and two climax values occurred in 14–16
cm and 20–22 cm layers, demonstrating that the production and usage of PAHs might reach peaks in the periods of 1956–1962 and
1938–1944. The booming economy and the navy battles of the SecondWorldWar might explain why the higher levels were detected in
the two layers. The result of principal component analysis (PCA) revealed that PAHs were primarily owing to the combustion product.
Down-cored variation of PCB concentrations was complex. Higher concentrations besides the two peaks being the same as PAHs were
detected from 4 to 8 cm, depositing from 1980 to 1992, which probably resulted from the disposal of the out-dated PCB-containing
equipment. The average Cl percentage of PCBs detected was similar to that of the mixture of Aroclor 1254 and 1242, suggesting
they might origin from the dielectrical and heat-transfer fluid. The total organic carbon (TOC) content played a prevalent role in the
adsorption of high molecular weight PAHs (> 4-ring), while no obvious relationship among total PCBs, the concentration of congeners,
and TOC was found.
