Record of PCB congeners, sorbents and potential toxicity in core samples in Indiana Harbor and Ship Canal

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• 作者：Andres  ; Martinez ; Keri C.  ; Hornbuckle  ; ;   ; ^{keri-hornbuckle@uiowa.edu}
• 关键词：PCBs ; Sediment ; Core ; Aroclor 1248 ; TEQs
• 刊名：Chemosphere
• 出版年：2011
• 出版时间：October 2011
• 年：2011
• 卷：85
• 期：3
• 页码：542-547
• 全文大小：697 K

文摘

Indiana Harbor and Ship Canal (IHSC) is an active navigational system that serves a heavily industrial area of southern Lake Michigan. We have determined the amount of polychlorinated biphenyls (PCBs), congener distributions, sorbent types and potential for dioxin-like PCB toxicity from two IHSC sediment cores. Vertical distributions of ¦²PCBs (sum of 161 individual or coeluting congeners) ranged from 410 to 91 000 and 1800 to 41 000 ng g^? dry weight (d.w.) for cores 1 and 2, respectively. Core 1 showed its highest accumulation rate for the year ?979 and exhibits a strong Aroclor 1248 signal in sediments accumulating over the last 60 years. It appears that from the late 1930s until the beginning of the 1980s there was a large and constant input of PCBs into this system. This pattern differs from lake cores from the Great Lakes region which commonly exhibit a rapid increase, a peak, followed by a sharp decrease in the PCB accumulation rates. Core 2 also has a strong Aroclor 1248 signal in the top layers, but deeper layers show evidence of mixtures of Aroclors and/or weathering processes. High levels of black carbon as a fraction of total organic carbon were found in both cores (median ?0 % ), which reflect the long history of local combustion sources. No strong relationship was found between ¦²PCB concentration and sorbents. Both cores contain dioxin-like PCBs that are highest in concentration below the surface. The high levels of PCBs in the deep sediments are of concern because of plans to dredge this system.