The utility and limits of applicability of a simple equilibrium partitioning model for predicting the maximum concentration of neutral organic compounds which can be accumulated by infaunal organisms exposed to a contaminated sediment were examined. Accumulation factors (AFs) for PCBs, the lipid normalized PCB concentration in organisms divided by the organic carbon normalized PCB concentration in sediments, were measured for PCBs in infaunal mollusks and polychaetes at field sites with a range of sediment Aroclor (A-1254) and total organic carbon (TOC) concentrations. The average AFs for A-1254 were found to be higher (X = 4.94; range 3.76-7.27) at sites with lower contaminant concentrations (15.0-48.3 ng A-12541g dry sediment) than at more contaminated sites (328-9,200 ng/g), where AFs were lower (2 = 2.62; range 1.14-5.04). AF data grouped on the basis of sediment A-1254 and TOC concentration differed statistically between, but not within each group. Significant differences in mean AFs were found between some species and between some PCB congeners. When all data were considered, the variability associated with AFs was lower than that found for bioaccumulation factors on a wet weight basis, indicating the utility of lipid and organic carbon normalization.

No abstract

The utility and limits of applicability of a simple equilibrium partitioning model for predicting the maximum concentration of neutral organic compounds which can be accumulated by infaunal organisms exposed to a contaminated sediment were examined. Accumulation factors (AFs) for PCBs, the lipid normalized PCB concentration in organisms divided by the organic carbon normalized PCB concentration in sediments, were measured for PCBs in infaunal mollusks and polychaetes at field sites with a range of sediment Aroclor (A‐1254) and total organic carbon (TOC) concentrations. The average AFs for A‐1254 were found to be higher (x̄ = 4.94; range 3.76–7.27) at sites with lower contaminant concentrations (15.0–48.3 ng A‐1254/g dry sediment) than at more contaminated sites (328–9,200 ng/g), where AFs were lower (x̄ = 2.62; range 1.14–5.04). AF data grouped on the basis of sediment A‐1254 and TOC concentration differed statistically between, but not within each group. Significant differences in mean AFs were found between some species and between some PCB congeners. When all data were considered, the variability associated with AFs was lower than that found for bioaccumulation factors on a wet weight basis, indicating the utility of lipid and organic carbon normalization.

No abstract

The concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzofurans (PCDF), polychlorinated dibenzo-p-dioxins (PCDD), and mercury (Hg) were determined in blubber and liver tissues of harbor seals (Phoca vitulina) collected along the northeast coast of the U.S. Average PCB concentrations in seal blubber (sum of congeners) were 12.0 micrograms/g (wet weight) with a range of 7.30 to 24.3 micrograms/g in 1980 and 6.66 micrograms/g (wet weight) with a range of 2.61 to 11.3 micrograms/g in 1990-1992. Comparisons between blubber data from this study and previous work indicated that the concentration of PCBs along the northeast coast of the U.S. may have decreased over the past twenty years. The average p,p'-DDE concentrations in seal blubber were 10.9 micrograms/g (wet weight) in 1980 with a range of 6.95 to 21.9 micrograms/g and 4.12 micrograms/g (wet weight) with a range of 1.83 to 7.84 micrograms/g in 1990-1992. Only trace amounts of PCDFs and PCDDs were found in a few blubber samples; levels in most tissues were below detection (3-5 pg/g) (wet weight). Trace amounts (< 30 ng/g) of phenanthracene, anthracene, and alkylated MW-178 compounds were found in some seal samples; all other PAH compounds were below the detection level (5-15 ng/g). Toxic equivalents (TEQ) of selected coplanar and mono-ortho PCB congeners and relative toxic equivalents (RTE) (pg total TEQ/microgram total PCB) were calculated, using recently proposed dioxin toxic equivalent factors (Ahlborg et al. 1994). The TEQs ranged from 41 to 315, and the RTEs ranged from 2.25 to 16.3.(ABSTRACT TRUNCATED AT 250 WORDS)

To simulate the bioaccumulation of neutral organic contaminants by infaunal benthos, the partitioning of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) between a contaminated estuarine sediment and admixed C-18coated silica particles was measured. The concentrations of lower chlorinated PCB congeners (less than five chlorine atoms per molecule) on the C-18-coated silica particles reached apparent steady state within 300 h while congeners with greater numbers of chlorine atoms required much greater time periods (greater than 1 year) to reach apparent steady state. Polycyclic aromatic hydrocarbons showed less partitioning from sediment to the C-18 particles than PCB congeners, although the log K ow ranges of the compounds in these comparisons were similar. The biota sediment accumulation factors, defined as the lipid-normalized contaminant concentration in an exposed organism divided by the organic carbon-normalized contaminant concentration of the sediment, were calculated for these exposures using the C-18 of the particles as the lipid. The results from these exposures agreed closely with those measured in studies where living benthic organisms were exposed to contaminated sediment.

No abstract

Abstract-To simulate the bioaccumulation of neutral organic contaminants by infaunal benthos, the partitioning of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) between a contaminated estuarine sediment and admixed C-18-coated silica particles was measured. The concentrations of lower chlorinated PCB congeners (less than five chlorine atoms per molecule) on the C-18-coated silica particles reached apparent steady state within 300 h while congeners with greater numbers of chlorine atoms required much greater time periods (greater than 1 year) to reach apparent steady state. Polycyclic aromatic hydrocarbons showed less partitioning from sediment to the C-18 particles than PCB congeners, although the log K ow ranges of the compounds in these comparisons were similar. The biota sediment accumulation factors, defined as the lipid-normalized contaminant concentration in an exposed organism divided by the organic carbon-normalized contaminant concentration of the sediment, were calculated for these exposures using the C-18 of the particles as the lipid. The results from these exposures agreed closely with those measured in studies where living benthic organisms were exposed to contaminated sediment.