Richard J. Pruell

Geochemical Study of Sediment Contamination in New Bedford Harbor, Massachusetts

Chemical analyses of sediment samples collected along a transect in New Bedford Harbor revealed a gradient of increasing concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDS), polychlorinated dibenzofurans (PCDFs), polycyclic aromatic hydrocarbons (PAHs) and several trace metals from the southern to the northern areas of the estuary. Although the concentrations of contaminants generally increased with distance north in the estuary for all classes of compounds, differences were observed between the trends for many of the compounds. These differences are probably due to both the sources and differential environmental behaviors of the compounds in the estuary. The primary sources of PCBs, PCDFs and trace metals appear to be industrial discharges either directly into the estuary or through combined sewer overflows. Additional inputs of PCDFs may have also impacted the lower portions of the harbor. These inputs may be from the combustion of sewage sludge containing high concentrations of PCBs at the New Bedford Harbor Municipal Wastewater Treatment Plant. The major inputs of PAHs and PCDDs are probably from urban runoff entering the harbor through combined sewer overflows and storm drains.

Accumulation of polychlorinated organic contaminants from sediment by three benthic marine species

A laboratory experiment was conducted to measure the accumulation of selected polychlorinated compounds by marine benthos exposed to environmentally contaminated sediment. Sandworms (Nereis virens), clams (Macoma nasuta), and grass shrimp (Palaemonetes pugio) were exposed to sediment collected from the Passaic River, New Jersey. All three species accumulated 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3, 7,8-TODD), 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF) and polychlorinated biphenyls (PCBs) from the sediment. In addition, a recently identified sulfur containing analog of tetrachlorinated dibenzofurans, 2,4,6,8-tetrachlorodibenzothiophene (2,4,6,8-TCDT), accumulated in the three species.Accumulation factors (AFs) were calculated (([organism]/lipid) / ([sediment]/total organic carbon)) and used to compare results among species and compounds. These comparisons showed that AFs measured for clams reached steady-state levels rapidly (10 days); however, steady-state Als values were not achieved until 70–120 days in sandworms. Grass shrimp were exposed to test sediments for only 28 days; therefore, steady-state concentrations could not be determined for this species.Although final contaminant concentrations were highest in the sandworms, AFs were generally higher for the clams and shrimp and lower for the sandworms. The AFs for 2,4,6,8-TCDT were significantly higher for shrimp than for sandworms and clams. PCB 153 showed higher AF values than those of the other compounds studied.Clams showed preferential accumulation of lower molecular weight PCB congeners which may be due to the very low lipid content in this species. Sandworms and especially shrimp appeared to metabolize congeners 52, 101, and 151 which all contain vicinal hydrogens in the meta and para regions of the molecule.

ENDOGENOUSLY-MEDIATED, PRETRANSLATIONAL SUPPRESSION OF CYTOCHROME P4501A IN PCB-CONTAMINATED FLOUNDER

Gonadally mature fish display strong sex-related differences in the content and activity of P4501A, the major polynuclear aromatic hydrocarbon-inducible P450 form in teleosts. Such differences appear related to plasma levels of the female sex steroid, estradiol (E2); however, neither the mechanism of estradiol suppression of P4501A nor the capacity for hormonal regulation to overcome P4501A induction by high concentrations of potent inducers are known. Gonadally mature flounder (Pseudopleuronectes americanus) were collected from Fox Island (FI), Rhode Island, a reference site, and New Bedford Harbor (NB), Massachusetts, a site highly contaminated with polychlorinated biphenyls (PCBs). Differences in flounder P4501A expression were determined at the level P4501A catalytic activity (measured as ethoxyresorufin-O-deethylase, EROD), P4501A protein content (immunoquantitated), and P4501A mRNA content (by Northern blot) as they relate to sex, reproductive status, and hepatic PCB content. Our results confirm that suppression of P4501A in gonadally mature female fish is probably due, at least in part, to elevated E2 titers, and demonstrate that such suppression occurs at a pretranslational level and, further, that endogenous regulation of P4501A expression can ‘override’ exogenous regulation by even high concentrations of P4501A inducers.

Extraction of organic contaminants from marine sediments and tissues using microwave energy

In this study, we compared microwave solvent extraction (MSE) to conventional methods for extracting organic contaminants from marine sediments and tissues with high and varying moisture content. The organic contaminants measured were polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polycyclic aromatic hydrocarbons (PAHs). Initial experiments were conducted on dry standard reference materials (SRMs) and field collected marine sediments. Moisture content in samples greatly influenced the recovery of the analytes of interest. When wet sediments were included in a sample batch, low recoveries were often encountered in other samples in the batch, including the dry SRM. Experiments were conducted to test the effect of standardizing the moisture content in all samples in a batch prior to extraction. SRM1941a (marine sediment). SRM1974a (mussel tissue), as well as QA96SED6 (marine sediment), and QA96TIS7 (marine tissue), both from 1996 NIST Intercalibration Exercise were extracted using microwave and conventional methods. Moisture levels were adjusted in SRMs to match those of marine sediment and tissue samples before microwave extraction. The results demonstrated that it is crucial to standardize the moisture content in all samples, including dry reference material to ensure good recovery of organic contaminants. MSE yielded equivalent or superior recoveries compared to conventional methods for the majority of the compounds evaluated. The advantages of MSE over conventional methods are reduced solvent usage, higher sample throughput and the elimination of halogenated solvent usage.

Germinomas and teratoid siphon anomalies in softshell clams, Mya arenaria, environmentally exposed to herbicides.

Seminomas and dysgerminomas are epizootic in softshell clams, Mya arenaria, from three Maine estuaries contaminated with herbicides. The first epizootic was discovered in 22% of clams collected as Searsport near Long Cove Brook and three culverts that conveyed heating oil and jet fuel spilled from a tank farm in 1971. Data from subsequent epizootiological studies and a series of long-term experimental exposures of softshell clams to no. 2 fuel oil, JP-4, and JP-5 jet fuel at the U.S. EPA, Environmental Research Laboratory in Narragansett, Rhode Island, and in the field did not support an etiology by these petroleum products. In the two recent epizootics reported here, the germinomas have been observed in 3% of the softshell clams collected from Roque Bluffs near Machiasport and from 35% of softshell clams collected from Dennysville. Mya collected at Dennysville had pericardial mesotheliomas and teratoid siphon anomalies in addition to gonadal neoplasms. Estuaries at Dennysville had been contaminated by herbicides in a 1979 accidental spray overdrift during aerial application of Tordon 101 to adjacent forests. Further investigation determined widespread use of the herbicides Tordon 101, 2,4-D,2,4,5-T, and other agrochemicals in an extensive forestry and blueberry industry in both the Roque Bluffs and the Dennysville areas. Herbicide applications at Searsport were confirmed for railroad property bordering Long Cove estuary and for Long Cove Brook adjacent to the estuary where a highway department reportedly cleans its spray equipment. Herbicide contamination is the only common denominator identified at all three sites where Mya have been found with gonadal neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS) ImagesFIGURE 5.FIGURE 6.

An examination of dechlorination processes and pathways in New Bedford Harbor sediments

Abstract Estuarine sediments from upper New Bedford Harbor, Massachusetts, which were heavily contaminated with polychlorinated biphenyls (PCBs), showed considerable compositional alterations of PCB residues relative to mixtures of Aroclor 1242 and 1254 standards, and PCB distributions present in sediments from lower New Bedford Harbor and Black Rock Harbor, Connecticut. The compositional alterations, which presumably resulted from reductive dechlorinations by bacteria, became more extensive with increasing PCB concentration and decreasing distance from the suspected PCB source, an electrical capacitor manufacturing plant. Three pathways which removed chlorine substituents from specific locations on PCB molecules were responsible for most of the observed dechlorinations. Considerable differences were found in the extent of dechlorination within sediment cores and between sampling sites in upper New Harbor. The most extensively altered PCB distribution was found in the 15–17·5 cm deep section of a core from nearest to the plants outfall. In most cores, less altered PCB residues were found in the 0–2·5 and 5–7·5 cm core sections than in the 15–17·5 cm section. Large variations in estimates of dechlorination rates were found, depending on the sample and the congener. The dechlorination processes found may decrease the potential toxicity and bioaccumulation potential of the PCB residues in these sediments.

Polychlorinated biphenyls concentration and cytochrome P-450E expression in winter flounder from contaminated environments

Abstract Reproductively mature winter flounder (Pseudopleuronectes americanus) were collected from three Northeastern US sites with different degrees of polychlorinated biphenyl (PCB) and polynuclear aromatic hydrocarbon (PAH) contamination. Liver PCB concentrations (measured by capillary electron-capture gas chromatography) in fish collected in 1987 and 1988 at New Bedford Harbor (NBH) ranged from 7·4 to 191 μg/g dry wt; at Gaspee Point 3·9–17·7 μg/g; and at Fox Island 1·6–15·1 μg/g. Levels of ethoxyresorufin O-deethylase (EROD) activity were similar in fish of the same reproductive status from the three sites; however, immunoquantitated P-450E homolog (the EROD catalyst) content was significantly higher in NBH fish. This suggests that P-450E catalytic activity is being suppressed in the livers of the NBH animals. Recent studies in our laboratory indicate that competitive inhibition of P-450E catalytic activity by specific PCB congeners is one likely mechanism of this suppression. Hepatic EROD activity and P-450E content were significantly lower in gravid females (EROD, 0·10–0·69 units per nmol P-450; P-450E, 8·4–19% of spectral P-450) than in spent females (EROD, 1·94–3·49; P-450E, 48–109%), and ripe males (EROD, 1·86–3·41; P-450E, 48–84%) at all sites. This is consistent with a hormonal effect on P-450E expression, and thus EROD activity, in gravid females. The data indicate a complex relationship between levels of EROD activity, or P-450E, and tissue PCB concentrations in highly contaminated fish. How these variables are linked to altered endocrine or gonadal function is not yet known.

The chemistry and toxicity of sediment affected by oil from the North Cape spilled into Rhode Island Sound

Abstract On 19 January 1996, the barge North Cape spilled more than three million liters of No. 2 fuel oil into Rhode Island Sound near Matunuck, Rhode Island. The toxicity and chemistry of this oil in two subtidal sediments were followed for more than 9 months. Maximum concentrations of polycyclic aromatic hydrocarbons (PAHs) in the sediments reached 730 μg / g dry weight (DW). Water samples taken immediately after the spill were phototoxic to embryos of the bivalve Mulinia lateralis. Total PAHs and toxicity to the amphipod Ampelisca abdita were high immediately after the spill, decreasing to background values ( 10 μg / g DW and

Organic contaminant distributions in sediments, polychaetes (Nereis virens) and American lobster (Homarus americanus) from a laboratory food chain experiment.

A laboratory experiment was conducted to investigate the transfer of organic contaminants from an environmentally contaminated marine sediment through a simple marine food chain. The infaunal polychaete, Nereis virens, was exposed to contaminated sediment collected from the Passaic River, NJ, USA, for 70 days. These polychaetes were then fed to the American lobster, Homarus americanus, for up to 112 days. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), 2,4,6,8-tetrachlorodibenzothiophene (TCDT), polychlorinated biphenyls (PCBs), and several chlorinated pesticides were accumulated by polychaetes following exposure to the contaminated sediment. Some of these contaminants were also accumulated by lobsters which were exposed to the contaminated sediment and/or fed contaminated polychaetes. Only the lesser chlorinated PCDDs and PCDFs (mostly tetra- and pentachlorinated congeners) and 2,4,6,8-TCDT were detected in the polychaetes and lobster. Significant alterations were noted in the PCB patterns found in both species, particularly the lobster. The non-ortho-substituted PCBs (such as congeners 77 and 126) became enriched in the PCB mixtures of the polychaetes and especially the lobsters relative to the sediment, probably because these congeners were not metabolized. These congeners and the 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalents of the PCB mixtures were enriched by a factor of about six in the lobsters relative to the sediment. Elimination of PCB congeners containing vicinal hydrogens in the meta-para region is consistent with cytochrome P450IIB-type metabolism. Based on the concentration trends for some PCB congeners and chlorinated pesticide ratios measured in the lobsters during this experiment, it appears that this metabolic system is inducible in the American lobster.

Bioavailability of 2,3,7,8-TCDD, 2,3,7,8-TCDF and PCBs to marine benthos from passaic river sediments

Abstract The bioaccumulation and depuration of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and polychlorinated biphenyls by marine benthos exposed to environmentally contaminated sediment were measured in a laboratory study. Sandworms ( Nereis virens ), clams ( Macoma nasuta ) and shrimp ( Palaemonetes puqio ) were exposed to sediment from the Passaic River, New Jersey for up to 180 days. Worms accumulated the highest concentrations of these compounds. Uptake and depuration rates were slowest in the worms and most rapid in the clams.