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

Abstract

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 ∑PCBs (sum of 161 individual or coeluting congeners) ranged from 410 to 91000 and 1800 to 41000 ng g−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 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 ~30%), which reflect the long history of local combustion sources. No strong relationship was found between ∑PCB 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.

Enhanced polychlorinated biphenyl removal in a switchgrass rhizosphere by bioaugmentation with Burkholderia xenovorans LB400

“…The soil was spiked with a mixture of PCB 52, PCB 77 and PCB 153 (99% pure) (Accustandard Inc., New Haven, CT) at the concentration of 500 ng g −1 each. This level of PCB contamination has been reported in soils and sediments previously (Martinez and Hornbuckle, 2011; Van Metre and Mahler, 2005). In this study we investigated the possibility of using switchgrass to clean up PCB contamination that is below the dredging requirement (50 ppm) but still poses a potential risk to human and environmental health.…”

PCB dechlorination hotspots and reductive dehalogenase genes in sediments from a contaminated wastewater lagoon

“…Preparation, extraction, and cleanup procedures for measuring PCB sediment concentrations were performed as described previously (Martinez and Hornbuckle 2011). Briefly, ~ 0.5 g of wet sediment was mixed with combusted diatomaceous earth, spiked with 50 ng of surrogate standard [PCB14 (3,5-dichlorobiphenyl), PCB65-d5 (2,3,5,6-tetrachlorobiphenyl-d5, deuterated) and PCB166 (2,3,4,4′,5,6-hexachlorobiphenyl)] and extracted by pressurized fluid extraction (ASE, Dionex ASE-300).…”

“…PCB congener profiles obtained from sediment samples were compared to the Aroclor 1248 congener profile, previously analyzed and quantified with the analytical method described above (Koh et al 2015), according to cosine theta analysis (DeCaprio et al 2005; Martinez and Hornbuckle 2011). The relative abundance (%) of meta -, para -, and ortho -chlorines in PCB congeners, the relative abundance (%) of PCB congeners with 1–3, 4–6, and 7–10 chlorines, and the molar dechlorination product ratio (MDPR) of PCB congener profiles was determined as shown below (Liang et al 2014).…”

Sediment pore water distribution coefficients of PCB congeners in enriched black carbon sediment

“…Core 1 was segmented every 0.15 m and Core 2 every 0.31 m. Details on the sampling and handling, as well as the concentration of PCBs in the bulk sediment ( C PCBi s ), total organic carbon (TOC), organic carbon (OC) and black carbon (BC) measurements have been previously reported in Martinez and Hornbuckle (2011). Briefly, ∑ C PCB s ranged from 1700 to 90 000 (ng g −1 dw), TOC from 7% to 24%, OC from 4% to 15% and BC from 3% to 10%.…”

“…Bulk PCB sediment concentrations were already determined (Martinez and Hornbuckle, 2011). Several published sediment pore water distribution coefficient models were tested against the measured values.…”