Assessments of toxicity from hudsonraritan sediments

A variety of measures were used in a national ranking of sediment toxicity. Sites in the Hudson/ Raritan Estuary and the upper East River ranked 1, 3, 5, and 7 nationally in toxic potential (Long and Morgan, 1991). In response, a large survey was conducted in 1991 in which the toxic potential of sediments collected from the Hudson/Raritan Estuary was measured directly by a number of different tests (Long et al., 1995; 1996). In the 1991 assessment, sediments from 69 percent of the stations were toxic in at least one test. Toxic-ity tests with the amphipod Ampelisca abdita indicated that 46 percent of sediments were toxic, while 41 percent of sites were classified as toxic using the Microtox bioluminescent bacterial assay, and only 27 percent of sediments inhibited survival or growth of bivalve embryos. Toxicity was most directly correlated with sediment PAH concentrations. In a later focused survey of Newark Bay, 84 percent of sediments were toxic to Ampelisca abdita and toxicity was more directly correlated with sediment concentrations of chlorinated hydrocarbons.

Gardinalia and Wade (1998)reevaluated national Mussel Watch results from 1994 through 1997 using a biomarker perspective. Using data on the relative abilities of individual PAHs, PCBs, and PCDDs to induce cytochrome P4501A (CYP1A) enzyme activity in rat liver hepatocytes, they calculated total induction equivalents (EIEs) for the body burdens of these contaminants measured in indigenous mussels. Despite their low induction equivalency factors, PAHs, because of their high concentrations comprised 95 to 99 percent of the total EIEs for all sites in the Hudson/Raritan Estuary (Table 30.1) and greater than 90 percent for the majority of sites around the country.

Beginning in 1993, the U.S. Environmental Protection Agency (USEPA) conducted another large assessment of the Hudson/Raritan Estuary through 1994 in their R-EMAP study (Adams, O'Connor, and Weisberg, 1998). This program was intended to evaluate long-term trends in the spatial patterns of sediment quality in the Harbor Estuary system. In addition to sediment chemistry and toxicity tests, this study also computed a Benthic Index of Biotic Integrity (B-IBI), based on benthic community structure. Sediments from half of the sites had at least one contaminant at levels that exceeded Long and Morgan's (1991) Effects Range Median (ER-M) values. Total PCBs, DDT, and Hg were the only toxicants whose average concentrations exceeded ER-M values. Degraded B-IBIs were also highly correlated with chemicals. Combining

Table 30.1. Contribution of PAHs, PCBs, and Dioxins/Furans (PCDD/PCDFs) to total induction equivalents in bivalves collected from the New York/New Jersey Harbor Estuary as part of the National Status and Trends Surveys 1994-1997

Location

NS&T ID

pg/g SEIs

PCBs

% Contribution PCDD/Fs

PAHs

Raritan Bay

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