Contaminated Sediments News

Recent Journal Articles of Interest

• Effects of Exposure of Bivalves to Contaminated Sediments on Phagocytic Activity of Hemocytes - Two bivalve species (Mya arenaria and Mactromeris polynima) were exposed to contaminated marine sediments from Baie des Anglais, Quebec, for 10 and 12 weeks, respectively, to determine if there was an effect on the phagocytic activity of hemocytes. The sediments contained elevated concentrations of both PAHs and PCBs. Uncontaminated beach sand was used as the sediment control. After one month, each bivalve species was sampled and hemocyte phagocytic activity was monitored by flow cytometry. Phagocytosis by hemocytes from M. polytiyma was significantly suppressed, whereas phagocytosis from M. arenaria was not different from the controls. At the end of the exposure periods, phagocytic activity of hemocytes from both species was suppressed. Suppression of phagocytosis was well correlated with the transfer of contaminants from the sediments via bioaccumulation in the bivalves as shown by the increased PCB body burden. The authors suggest that the results support the use of bivalves as sentinel species to survey sediment contamination and the usefulness of hemocyte phagocytic activity as an indicator of exposure to organic contaminants.

  Source: Fournier, M., J. Pellerin, M. Lebeuf, P. Brousseau, Y. Morin, and D. Cyr. 2002. Effects of exposure of Mya arenaria and Mactromeris polynyma to contaminated marine sediments on phagocytic activity of hemocytes. Aquat Toxicol 59(1-2):83-92.

• Fate of PAH-Contaminated Sediments at the Wyckoff/Eagle Harbor Superfund Site - Eagle Harbor, Washington, was formerly the site of the Wyckoff wood-treatment facility. Historical creosote releases from the early 1900s to 1988 into the harbor resulted in substantial accumulation of PAHs in the sediments over time. This study focused on the fate and distribution of the PAH-contaminated sediments by analyzing 10 sediment cores with total petroleum hydrocarbon (TPH) fingerprinting. Distribution of 50 PAH analytes and sediment age dating revealed the contributions of three distinct sources of PAHs: creosote, urban runoff, and natural background. Surface sediments in the cores closest to the Wyckoff facility were dominated by urban runoff and weathered creosote; the deeper sediments (> 30 cm) were heavily contaminated with relatively unweathered creosote and some pure-phase creosote. Cores located the furthest from the area of contamination were dominated by urban runoff. PAH concentrations in cores sampled furthest from the facility increased significantly with proximity to the northern shore of the harbor, which is more heavily developed and is where all motor vehicle traffic enters and exits the island through the Bainbridge Island ferry terminal. Deeper sediments in these cores were contaminated with natural background PAHs, representing preurbanization sediments. The authors believe this knowledge that urban runoff has been a consistent source of PAHs to the harbor's sediments for the past 50-70 years may effect future sediment management decisions in the harbor.

  Source: Brenner, R.C., V.S. Magar, J.A. Ickes, J.E. Abbott, S.A. Stout, E.A. Crecelius, and L.S. Bingler. 2002. Characterization and FATE of PAH-contaminated sediments at the Wyckoff/Eagle Harbor Superfund Site. Environ Sci Technol 36(12):2605-13.

• Impact of Irradiation and PAH Spiking on Microbial Populations in Sediment - Deveopment of methods was undertaken to generate well-characterized, PAH-spiked, aged but minimally altered sediments for fate, biodegradation, and bioavailability experiments. Changes in indigenous bacterial population were monitored in mesocosms composed of clean San Diego Bay sediments, with and without exposure to gamma radiation, and that was then spiked with five different PAHs and hexadecane. Although phenanthrene and chrysene degraders were present in unspiked sediments and increased during handling, PAH spiking of nonirradiated sediments led to dramatic increases in their numbers. Phenotypic characterization of isolates able to grow on phenanthrene or chrysene put them in several genera of marine bacteria including: Vibrio, Marinobacter or Cycloclasticus, Pseudoalteromonas, Marinomonas, and Halomonas. This is the first report that marine PAH degraders have been identified in the latter two genera, thereby increasing the diversity of marine bacteria with this ability. Even after exposure to the highest irradiation dose (10 megarads), heterotrophs and endospore formers reappeared within weeks. Although bacteria from unirradiated sediments had the ability to grow on and mineralize phenanthrene and chrysene, irradiation prevented the reappearance of PAH degraders for up to 4 months, allowing spikes to age in the sediments, thus modeling biodegradation in marine sediments.

  Source: Melcher, R.J., S.E. Apitz, and B.B. Hemmingsen. 2002. Impact of irradiation and polycyclic aromatic hydrocarbon spiking on microbial populations in marine sediment for future aging and biodegradability studies. Appl Environ Microbiol 68(6):2858-68.

• PCB-Degrading Microbial Communities in Sediments - Recent studies on degradation of PCBs have focused on the (1) use of experimental enrichment cultures to obtain PCB-degrading communities, and (2) use of culture-independent approaches to characterize natural and experimental PCB-degrading communities and identify key members in this process. PCB-degrading communities are extremely diverse. Composite bacteria-mineral biofilm communities have been described. Community PCB metabolism may lead to protoanemonin formation, a dead-end product in some situations but, in others, a productive intermediate. Degradation of PCBs in anaerobic settings have been provided by analysis of isotope fractionation and preferred enantiomer degradation. The author describe the first defined community capable of dehalorespiration of PCBs, and its important community members are identified. This study provides an overview of the current knowledge of anaerobic and aerobic degradation of PCBs by microbial consortia and in the environment, including new approaches to determine in situ PCB degradation.

  Source: Abraham, W. R., B. Nogales, P.N. Golyshin, D.H. Pieper, and K.N. Timmis. 2002. Polychlorinated biphenyl-degrading microbial communities in soils and sediments. Curr Opin Microbiol 5(3):246-53

• Bioavailability of Metals to Amphipod - Could reduced eutrophication be a potential environmental threat because of increased mobility and bioavailability of trace metals? This question was addressed by oxygenating intact sediment cores, varying in redox potential and salinity, in a test system containing the amphipod Monoporeia affinis. Results show a low mobility of metals during oxygenation, and despite high concentrations of metals in sediments, only Pb showed a notable degree of bioaccumulation. Cadmium was bioaccumulated particularly in freshwater sediment, and body burden of Cd was related to salinity, porewater, and sediment concentrations. Despite high sediment and porewater concentrations of Cu and Zn, no relationship was recorded to body burden. For three of four tested metals, Cd, Pb, and Zn, metals in sediment were more important for body burdens in amphipods as compared to metals in porewater. Food, rather than interstitial water, therefore seems to be the main route of metal contaminants to these amphipods. Furthermore, this observed low release of metals from sediments and low body burden significance of porewater metals indicate that ameliorated oxygen conditions in contaminated sediments may be regarded as a minor environmental threat for one of the most important Baltic benthic organisms.

  Source: Wiklund, A.K. and B. Sundelin. 2002. Bioavailability of metals to the amphipod Monoporeia affinis: interactions with authigenic sulfides in urban brackish-water and freshwater sediments. Environ Toxicol Chem 21(6):1219-28.

• Methyltransferase: an enzyme assay for microbial methylmercury formation in acidic sediments - The authors present a method to quantify methylation of mercury by a methyltransferase pathway. This pathway is one of the biochemical pathways responsible for biological mercury methylation. Protein is first extracted from environmental samples, and the mercury methyltransferase (HgMT) activity of soil extracts is calculated by assessing increases in methyltransferase activity induced by Hg addition. In enzyme extracts, HgMT activity correlates with net MeHg production and Hg consumption. This suggests that HgMT activity can be used to estimate MeHg production in field samples. The authors report that over a three-month period in a freshwater wetland, HgMT activity correlated with net MeHg concentrations. In addition, HgMT activity predicted gross MeHg formation in freshwater wetlands and in laboratory microcosms calculated using previously published rate constants. The results show that a methyltransferase assay can accurately predict MeHg formation under field and laboratory conditions.

  Source: Siciliano, S. D., and D.R. Lean. 2002. Methyltransferase: an enzyme assay for microbial methylmercury formation in acidic soils and sediments. Environ Toxicol Chem 21(6):1184-90.

• Uncertainty and Variability in Predicted Risks of Trophic Transfer of PCBs - Biomagnification of organochlorine and other persistent organic contaminants by higher trophic level organisms represents a significant source of uncertainty and variability in evaluating potential risks associated with dredge material disposal. The authors proposed a disaggregation of uncertain and variable parameters based on: (1) availability of supporting data; (2) the specific management and regulatory context (in this case, of the U.S. Army Corps of Engineers/U.S. EPA tiered approach to dredged material management); and (3) professional judgment and experience in conducting probabilistic risk assessments. The authors further describe and evaluate several sources of uncertainty and variability in estimating risk to human health from trophic transfer of PCBs using a case study of sediments obtained from the New York-New Jersey Harbor that are being evaluated for disposal at an open water off-shore disposal site. Estimates of PCB fish concentrations and dietary PCB doses to humans ingesting fish are expressed as distributions of values, of which the arithmetic mean or mode represents a particular fractile. Using a food chain biomagnification model, the distribution of risk values is obtained by specifying distributions for input parameters disaggregated to represent either uncertainty or variability. Only those sources of uncertainty that could be quantified were included in the analysis. The analysis suggests that variability in human exposure parameters is greater than the uncertainty bounds on any particular fractile, given the described assumptions.

  Source: von Stackelberg, K. E., D. Burmistrov, D.J. Vorhees, T.S. Bridges, and I. Linkov. 2002. Importance of uncertainty and variability to predicted risks from trophic transfer of PCBs in dredged sediments. Risk Anal 22(3):499-512.

• Assessment of PAH Contamination in Estuarine Sediments - Using the equilibrium partitioning-toxic unit (EqP-TU) approach, estimates of the potential acute toxicity of PAH residues to aquatic organisms in British estuarine sediments indicate that sediments from the Clyde and Mersey estuaries and Southampton Water have the highest mean toxicities. The author proposes that PAH residues probably originate from a combination of specific industrial sources and inputs from surrounding conurbations via combustion and run-off. Maximum sediment toxicities were evident at specific sites in Southampton Water near a chemical plant outfall and in sediments around docks on the Wear and Clyde. The author discusses limitations of the EqP-TU approach, particularly with regard to the potential for the over estimation of toxicity due to high concentrations of non-bioavailable high molecular weight PAHs occluded in combustion particles.

  Source: Rogers, H.R. 2002. Assessment of PAH contamination in estuarine sediments using the equilibrium partitioning-toxic unit approach. Sci Total Environ 290(1-3):139-155.

• Bioaccumulation of PCBs in Aquatic Biota From a Tidal Freshwater Marsh Ecosystem - To assess baseline concentrations of PCBs and bioaccumulation in finfish species, water, sediments, and aquatic biota, samples were taken in a tidal river-marsh on the Potomac River near Washington, DC (USA). In the wetland, the mean sediment total-PCB concentration was 50 ng/g dry weight, and mean concentrations in biota ranged from 150 ng/g to 450 ng/g wet weight. The highest PCB concentrations found were detected in channel catfish. The median biota-sediment accumulation factor (BSAF) estimated in all finfish species for total-PCBs was 2.9. However, some of the individual and co-eluting PCB congeners had median BSAFs that were substantially greater (e.g., congener numbers 42, 74, 182/187/128, and 171) or lower (e.g., congener numbers 18/15, 45, 185, and 208) than the total-PCB average. Apparent bioaccumulation factors (biota/water PCB concentration ratios) for PCB congeners showed a parabolic relation with n-octanol/water partition coefficients, confirming some previous investigations. No clear trend was apparent between bioaccumulation factors and trophic level.

  Source: Crimmins, B. S., P.D. Brown, D.P. Kelso, and G.D. Foster. 2002. Bioaccumulation of PCBs in aquatic biota from a tidal freshwater marsh ecosystem. Arch Environ Contam Toxicol 42(4):396-404.

• PCDD/F and PCB History in Dated Sediments of a Rural Lake - Polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB) concentrations were analysed from a sediment core, collected from a remote lake in Finland. The deepest subsamples were analysed from a depth of 4.0 m, and were more than 8000 years old. At the surface of the sediment core, low concentrations of industrial contamination (background levels) were detected. A characteristic PCDD/F congener profile was detected in all pre-industrial sediment layers. The order of concentrations was OCDD > 1,2,3,4,6,7,8-HpCDD > 1,2,3,7,8,9-HxCDD > 1,2,3,4,7,8-HxCDD > 2,3,7,8-TCDD, and concentrations of 2,3,7,8-chlorinated dibenzofurans were below the detection limit. Other authors have described similar congener profiles in samples for which natural PCDD/F formation has been proposed. PCBs were also present at low concentrations in all of the sediment samples.

  Source: Isosaari, P., H. Pajunen, and T. Vartiainen. 2002. PCDD/F and PCB history in dated sediments of a rural lake. Chemosphere 47(6):575-83.

• Toxicity of Selenomethionine- and Seleno-Contaminated Sediment - The acute toxicity of four chemical species of selenium to juvenile amphipods (Corophium sp.) was assessed in water-only tests. The authors found the seleno-amino acid compounds seleno-L-methionine and seleno-DL-cystine were more toxic (96-h LC(50) values of 1.5 and 12.7 microg Se/L) than inorganic selenite and selenate (96-h NOEC values of 58 and 116 microg Se/L), respectively. New marine sediment testing procedures were developed using juvenile and adult Corophium sp and both life stages were highly sensitive to seleno-L-methionine-spiked sediment. Juveniles were almost five times more sensitive (10-day LC50 of 1.6 microg Se/g dry weight) compared to (7.6 microg Se/g dry weight) for the adults. Sediment collected from three sites in Lake Macquarie with elevated concentrations of total selenium had no effect on the survival of adult Corophium over 10 days.

  Source: Hyne R.V., A,C, Hogan, F. Pablo, and A. C. Roach. 2002. Toxicity of selenomethionine- and seleno-contaminated sediment to the amphipod Corophium sp. Ecotoxicol Environ Saf 52(1):30-7.

• Heavy Metal Concentrations in Spiders Living in Intertidal Sediments - This study was directed at identifying the most important factors that determine the bioavailability of heavy metals to the spider, Pirata piraticus, living in intertidal sediments of the Scheldt estuary (Flanders, Belgium). At five sites representing varying degrees of metal contamination and salinity, the superficial sediment layer was characterised for physico-chemical properties and heavy metal (Cd, Cu, Zn) content. Spiders were also collected at the same sites and were analysed for Cd, Cu and Zn. Higher Cd, Cu and Zn contents were detected in spiders on sites with lower total metal contents in the sediment which were closest to the river mouth, and were characterised by higher salinity. Significant, positive correlations were found between the chloride content of the sediments and the Cd, Cu and Zn content of P. piraticus. These field results indicate that salinity, cation exchange capacity, and exchangeable metal contents are most important in determining bioavailability of heavy metals in intertidal sediments.

  Source: Du Laing, G., N. Bogaert, F.M. Tack, M.G. Verloo, and F. Hendrick. 2002. Heavy metal contents (Cd, Cu, Zn) in spiders (Pirata piraticus) living in intertidal sediments of the river Scheldt estuary (Belgium) as affected by substrate characteristics. Sci Total Environ 289(1-3):71-81.

• Distribution and Transportation of PAHs in Surface Sediments - Based on the quantitative and qualitative analysis of sixteen PAHs with GC and GC-MSD, the concentrate distribution and transportation characteristics of PAHs in suspended particulate matter (SPM) and surface sediments (SS) from the Pearl River Estuary were studied. Whether in SPM or in SS, the concentration distribution of PAHs were characterized by acenaphthene (mean 55.5 microg/g in SPM, 226 ng/g in SS) with subordinate amounts of the tri- and tetra-cycle PAHs such as fluorene, fluoranthene, phenaphene and pyrene. However, PAHs had different composition and concentration in SPM and SS. Pentacyclic PAHs appeared in SS and seldom in SPM because of their low solubility and high molecular weight. The concentrations of the tri-, tetracyclic PAHs in SPM were 100-300 times higher than those in SS. The total PAHs varied from 12-281 microg/g (mean 77 microg/g) in SPM and 208-1849 ng/g (mean 537 ng/g) in SS respectively. There were similar correlations between the concentrations of PAHs in SPM and salinity, and between the distance of the stations from the river outlet moving seawards and the concentrations of PAHs. These indicated that PAHs were degraded or transported along with the salinity gradient in SPM and the distance from the river outlet in SS. It was also suggested that the sources of these PAHs are from sewage and shipping discharge-pollutants. Pearl River Estuary had been lightly contaminated by PAHs.

  Source: Wang, X., H. Hong, L. Xu, W. Chen, and Z.Zhang 2002. Distribution and transportation of polycyclic aromatic hydrocarbons in suspended particulate matter and surface sediment from the Pearl River Estuary. J Environ Sci Health Part A Tox Hazard Subst Environ Eng 37(4):451-63.

• Method of In Situ Immobilization and Reduction of Metal Bioavailability in Contaminated Sediments - The authors provide improved methods and compositions for decreasing the bioavailability of metals in soil. In general, the methods comprise mixing a source of phosphorus and an oxide of manganese with the contaminated soil so as to reduce metal bioavailability in the soil. The phosphorus source and oxide of manganese can be individually mixed with the soil, or can be provided as a premixed powder or granule to be mixed with the contaminated soil. The pH of the soil is then adjusted to, and maintained at a level of at least 7. The preferred phosphorus sources recommended by the authors include phosphate rock, alkali and alkaline earth metal phosphates, ammonium phosphates, ammonium orthophosphates, orthophosphoric acid, and superphosphates. Recommended oxides of manganese include MnO2, Mn3 O4, birnessite, cryptomelane, and psilomelanes.

  Source: Pierzynski, G. M. and G.M. Hettiarachchi. 2002. Method of in situ immobilization and reduction of metal bioavailability in contaminated soils, sediments, and wastes. No literature citation provided.

• Fire Retardant Foam as a Source of Bromindated Diphenyl Ethers - Five tetra- to hexabrominated diphenyl ether (BDE) congeners (BDE-47, -99, -100, -153 and -154) are the most frequently reported in humans and wildlife. The commercial penta-BDE product, used predominantly as a flame-retardant in polyurethane foam, consists primarily of these same congeners. Frogs, housed on flame retardant-treated polyurethane foam, accumulated 10,100 mug/kg (wet weight) of the above BDEs. Crickets maintained with the frogs as food contained 14,400 mug/kg. The authors suggest that the crickets browsed directly on the foam and, in turn, were consumed by the frogs. In all three matrices, BDE congener composition matched that of the penta-commercial product. Similar congeners were also observed in soil and stream sediments collected near a polyurethane foam manufacturing plant. Sunfish fillets sampled from a nearby, off-site pond contained 624 mug/kg (lipid basis). Sewage treatment plant (STP) sludge exhibited these same congeners at 1370 mug/kg (dry weight). The fully brominated congener predominant in the commercial deca-BDE product (BDE-209), was also present at 1470 mug/kg. While no known polyurethane foam manufacturers discharged to this plant, the distribution pattern of the low brominated congeners in the sludge matched that of the penta-product. The authors discuss disintegration of the foam as a mechanism for environmental release of the BDE congeners.

  Source: Hale, R. C., M.J. La Guardia, E. Harvey, and T. M. Mainor. 2002. Potential role of fire retardant-treated polyurethane foam as a source of brominated diphenyl ethers to the US environment. Chemosphere 46 (5): 729-735.