PCBs Dioxins DDT and Chlordane

PCBs. The particle-associated contaminant most closely associated with the HudsonRiver is PCBs. In December 2000, the USEPA proposed the dredging of 2.65 million cubic yards of sediment from the Upper Hudson River containing an estimated 150,000 pounds of PCBs from the discharges of two General Electric capacitor plants (USEPA, 2000; Baker et al., 2001; Fig. 26.1). The analysis of dated sediment samples and the development of contaminant chronologies played a critical role in the evolution of our understanding of the importance of this and other PCB sources to the Hudson.

The development of PCB chronologies provided direct evidence that the removal of the first dam downstream of the General Electric inputs to the Upper Hudson resulted in an unprecedented PCB downstream transport event (Bopp et al., 1982; Bopp and Simpson, 1989). PCB component analysis has been used to determine the influence of the Upper Hudson source on sediments depositing in the New York/New Jersey Harbor along the main stem of the Hudson (Bopp et al., 1981; Bopp and Simpson, 1989; Chillrud, 1996). Analyses of dated sediments from other parts of the harbor complex have provided information on significant PCB sources to the western side of New York/New Jersey related to discharges of municipal waste-water (Bopp et al., 1991; Bopp et al., 1998). Recent work has focused on the characterization of atmospheric PCB sources through the analysis of dated sediment core samples from Central Park Lake and reservoirs of the New York City municipal water supply (Chaky et al., 1998; Chaky, 2003).

Dioxin. The best known case of dioxin contamination in the area involves the synthesis of compounds used in the formulation of Agent Orange at what is now commonly referred to as the 80 Lister Avenue Superfund site on the lower Passaic River in the western part of New York/New Jersey Harbor (Fig. 26.1). This dioxin source is characterized by a high relative proportion of 2,3,7,8-TCDD (Hay, 1982; Bopp et al., 1991), the congener with the highest toxic equivalency factor (TEF) (NATO, 1988; van den Berg et al., 1998). Its influence has been traced to Newark Bay and possibly up the Hackensack River as a result of tidal flow (Bopp et al., 1991). More recent analysis, based on the ratio of 2,3,7,8-TCDD to total TCDDs, suggests that as much as half of the 2,3,7,8-TCDD in main stem Hudson sediments as far upstream as the George Washington Bridge (Fig. 26.1) could be related to this source (Chaky, 2003). Significant dioxin contamination has also been found in sediments of the Upper Hudson and at a site just downstream of the Federal Dam at Troy, New York (Bopp et al., 1998). The total toxic equivalents are comparable to those found in Newark Bay sediments, but are derived dominantly from hexa-through octachlo-rinated congeners.

DDT and chlordane. The 80 Lister Avenue site also plays a significant role in the DDT contamination in sediments of the New York/New Jersey Harbor. DDT was manufactured at the facility from the mid-1940sto 1958-59 whenproduction was moved to Texas (Diamond Shamrock Corporation, 1983). This production history imparts a unique temporal signal on sediment chronologies influenced by this source - a peak in DDT-related compounds in samples deposited in the 1940s through the early 1950s. In other natural water systems (Alderton, 1985), including the mid-tidal Hudson (site 6; Fig. 26.1; Bopp etal., 1982) and Jamaica Bay (site 9; Fig. 26.1; Bopp et al., 1991), peaklevels of DDT-derived compounds occur in samples deposited in the 1960s to early 1970s, reflecting overall U.S. production and use history. A 1940s to early 1950s peak in DDT-related compound levels was clearly seen in NewarkBaysediments (site 12; Fig. 26.1;Bopp etal., 1991) and has been reported in sediments from the Arthur Kill (site 10; Fig. 26.1; Robinson, 2002). In a core from southern Raritan Bay (Fig. 26.1) peak levels of DDT-derived compoundswerefoundnear the bottom of the core in sediments that dated from the 1950s (Robinson, 2002). In recently deposited sediments (1980s to 1990s), cores from the Arthur Kill and Kill Van Kull (site 11; Fig. 26.1) have the highest levels of DDT-derived compounds of any of our HudsonBasin sites (Bopp et al., 1998;Robinson, 2002). The data suggest a local source.

Based on analyses of dated sediment samples, the Passaic and Hackensack Rivers have been identified as major sources of chlordane to the western harbor (Bopp et al., 1998). Although relatively few samples have been analyzed, levels of chlordane in Hudson sediments upstream of New York/New Jersey Harbor appear to be quite low relative to those observed in the western part of the harbor complex (Robinson, 2002).

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