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

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

Andres Martinez and Keri C Hornbuckle
Chemosphere, Vol.85(3), pp.542-547
10/2011
DOI: 10.1016/j.chemosphere.2011.08.018
PMCID: PMC3222236
PMID: 21899876
url
https://www.ncbi.nlm.nih.gov/pmc/articles/3222236View
Open Access

Abstract

► Sediment cores were collected from one of the largest direct tributary source of PCBs to Lake Michigan. ► PCBs (160 peaks including dioxin-like PCBs), black carbon, and TOC were measured. ► PCBs increase with depth with the highest correlating to years 1940 through 1990. ► The system exhibits an unusually strong Aroclor 1248 signal. 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 ΣPCBs (sum of 161 individual or coeluting congeners) ranged from 410 to 91000 and 1800 to 41000ngg−1 dry weight (d.w.) for cores 1 and 2, respectively. Core 1 showed its highest accumulation rate for the year ∼1979 and exhibits a strong Aroclor 1248 signal in sediments accumulating over the last 60years. 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 ∼30%), which reflect the long history of local combustion sources. No strong relationship was found between ΣPCB 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.
PCBs Sediment TEQs Aroclor 1248 Core

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