The U.S. Environmental Protection Agency is in the process of developing Sediment Quality Criteria (SQC) to specify the acceptable degree of risk from sediment-mediated chemical exposure for the protection of benthically-coupled organisms. In this study, potential differences in chemical exposure for benthic organisms of differing habitats or feeding types were evaluated through the use of Biota-Sediment Accumulation Factors (BSAFs). It was hypothesized that If species of different habitats have similar exposures, then the BSAF values should not be different. The BSAFs are calculated using the concentrations of chemicals in an organism (&mgr;g/g lipid) divided by the concentrations of the same chemicals in sediment (&mgr;g/gOC). Data from both freshwater and saltwater studies that met specified criteria for data quality were obtained from published papers or reports. These included three laboratory and five field studies containing 27 species and 4054 BSAF values. The BSAFs were intercompared for similarity of central tendency as grouped by chemical class (PCBs, PAHs, pesticides), individual species, and species grouped by habitat (infaunal deposit feeder, scavenger, filter feeder, and benthically-coupled fish). Plots of BSAFs grouped by class and KOW revealed that the BSAFs for the PAHs were uniformly lower (mean 0.34) than the PCB (1.03) or pesticide (1.36) classes. For the PCBs, the BSAFs for all species exhibited a KOW dependency with decreased bioaccumulation evident above and below the range of 5.99-7.27 log10 KOW. In order to optimize the detection of species/habitat differences in the BSAFs, further analyses were segregated by chemical class and excluded PCB data outside the above KOW range. These analyses revealed similar BSAF values for various species both within and among habitat groups, and indicated that the sum total of exposures from all routes is similar across species. This similarity of chemical exposure across benthic species, and the similarity of sensitivities between benthic species and species used to derive WQC FCVs supports the applicability of SQC for all benthic organisms as a group.

The U.S. Environmental Protection Agency is in the process of developing Sediment Quality Criteria (SQC) to specify the acceptable degree of risk from sediment-mediated chemical exposure for the protection of benthically-coupled organisms. In this study, potential differences in chemical exposure for benthic organisms of differing habitats or feeding types were evaluated through the use of Biota-Sediment Accumulation Factors (BSAFs). It was hypothesized that If species of different habitats have similar exposures, then the BSAF values should not be different. The BSAFs are calculated using the concentrations of chemicals in an organism (&mgr;g/g lipid) divided by the concentrations of the same chemicals in sediment (&mgr;g/gOC). Data from both freshwater and saltwater studies that met specified criteria for data quality were obtained from published papers or reports. These included three laboratory and five field studies containing 27 species and 4054 BSAF values. The BSAFs were intercompared for similarity of central tendency as grouped by chemical class (PCBs, PAHs, pesticides), individual species, and species grouped by habitat (infaunal deposit feeder, scavenger, filter feeder, and benthically-coupled fish). Plots of BSAFs grouped by class and KOW revealed that the BSAFs for the PAHs were uniformly lower (mean 0.34) than the PCB (1.03) or pesticide (1.36) classes. For the PCBs, the BSAFs for all species exhibited a KOW dependency with decreased bioaccumulation evident above and below the range of 5.99-7.27 log10 KOW. In order to optimize the detection of species/habitat differences in the BSAFs, further analyses were segregated by chemical class and excluded PCB data outside the above KOW range. These analyses revealed similar BSAF values for various species both within and among habitat groups, and indicated that the sum total of exposures from all routes is similar across species. This similarity of chemical exposure across benthic species, and the similarity of sensitivities between benthic species and species used to derive WQC FCVs supports the applicability of SQC for all benthic organisms as a group.

ABSTRACT. During summer 1985, reduced feeding, reproductive failure and massive mortalities were observed in populations of the blue mussel Mytilus edulis during an extremely dense algal bloom (106 cells ml-l) in Narragansett Bay, Rhode Island (USA). The dominant alga was an extremely small (1 to 211m diameter) non-flagellated chrysophycean form previously unobserved in coastal or offshore waters. Effects of the alga on clearance rates of mussels were tested using natural particulates (NBP) collected from Narragansett Bay during the bloom. Reductions in clearance rate were independent of cell size and extra-cellular exudates of the bloom alga. Experiments repeated with the hard shell clam Mercenaria mercenaria produced similar clearance rate responses. In examining density-dependent effects, NBP concentrations below 2.5 X 10' particles ml-' allowed normal clearance of a food alga (Isochrysis galbana) and NBP, while significant reductions in the clearance of food algae were observed at NBP concentrations above 5.0 X 10' particles ml-l. In Narragansett Bay, NBP densities ~ncreased from 9 X 10' cells ml-' at seaward stations to above 15 X 105 cells ml-' in the upper bay. High mortality in indigenous mussels was coincident with peak bloom conditions, varylng from 30 to 100 YO at stations along the main axis of the bay. In addition, complete reproductive failure of the population was apparent. This effect could not otherwise be explained by environmental conditions of temperature, salinity or dissolved oxygen concentration. It is concluded that starvation stress induced by noxious properties of the bloom alga in combination with seasonal effects (reproductive stage, temperature) was the cause of the demise of M. edulis.

Aims  Ciraparantag is a reversal agent for anticoagulants including direct oral anticoagulants. The aim was to evaluate the efficacy and safety of ciraparantag to reverse anticoagulation induced by apixaban or rivaroxaban in healthy elderly adults. Methods and results  Two randomized, placebo-controlled, dose-ranging trials conducted in healthy subjects aged 50–75 years. Subjects received apixaban (Study 1) 10 mg orally twice daily for 3.5 days or rivaroxaban (Study 2) 20 mg orally once daily for 3 days. At steady-state anticoagulation subjects were randomized 3:1 to a single intravenous dose of ciraparantag (Study 1: 30, 60, or 120 mg; Study 2: 30, 60, 120, or 180 mg) or placebo. Efficacy was based on correction of the whole blood clotting time (WBCT) at multiple timepoints over 24 h. Subjects and technicians performing WBCT testing were blinded to treatment. Complete reversal of WBCT within 1 h post-dose and sustained through 5 h (apixaban) or 6 h (rivaroxaban) was dose related and observed with apixaban in 67%, 100%, 100%, and 17% of subjects receiving ciraparantag 30 mg, 60 mg, 120 mg, or placebo, respectively; and with rivaroxaban in 58%, 75%, 67%, 100%, and 13% of subjects receiving ciraparantag 30 mg, 60 mg, 120 mg, 180 mg, or placebo, respectively. Adverse events related to ciraparantag were mild, transient hot flashes or flushing. Conclusions  Ciraparantag provides a dose-related reversal of anticoagulation induced by steady-state dosing of apixaban or rivaroxaban. Sustained reversal was achieved with 60 mg ciraparantag for apixaban and 180 mg ciraparantag for rivaroxaban. All doses of ciraparantag were well tolerated.

This study investigated the interferences caused by high humic acid concentrations on the adsorption of coplanar and noncoplanar polychlorinated biphenyls (PCBs) on coconut shell activated carbon. In particular, the research focuses on the application of activated carbon as a reactive cap for contaminated sediment sites, a possible intervention to reduce contaminant flux through pore water, and to organisms in aquatic environments. Kinetic and equilibrium studies were conducted using activated carbon as a sorbent for individual PCB congeners including BZ 1, 52, 77, 153, and 169, respectively, in the presence and absence of humic acid. Results showed that preloading of activated carbon with humic acid significantly reduced the adsorption affinity for all selected PCB congeners. Experiments conducted without preloading of activated carbon demonstrated that desorption upon subsequent spiking with humic acid (simulating long-term exposure to pore water that contains high humic acid concentrations) was not found to be statistically significant, and varied with coplanarity of PCBs. Results provide important information for the design of reactive caps in sediments where high concentrations of dissolved organic carbon are found, and highlight the importance of considering site conditions when designing effective reactive caps.

The USACE-Norfolk District (NAO) and the City of Petersburg, VA are working toward restoring the former Appomattox River Federal Navigation Channel. In this effort, ~350,000 cubic yards of deposited sediment will be removed from-14 feet MLLW up to + 6 feet MLLW over a ~1 mile reach of the Appomattox River. Historical industrial uses have resulted in PAH contamination exceeding 500 mg/kg on average, with hotspots detected in excess of 5,000 mg/kg based on USACE 2004 analytical data. To support the NAO with its assessment of contaminant distribution, upland source control measures, dredge sequencing, sediment capping requirements to address residual contaminants and beneficial reuse options for the dredged material have been evaluated. In support of beneficial reuse as agricultural soil, a lab treatability study has been completed to assess biodegradation potential. Total PAH concentrations in three laboratory test pans after 46 weeks of treatment indicated an overall 80% contaminant reduction using an enhanced bioremediation process. The results of this bench-scale study were used as the basis for the design of a pilot field-scale landfarm study demonstration undertaken during July 2007. After five months of treatment, LMW PAHs in landfarm material appear to have degraded first while HMW PAHs are degrading more slowly, a process which generally mimics the results of the laboratory investigation. Conclusions based on the laboratory and landfarm activities as well as the technical and regulatory issues that must be resolved to allow eventual placement of the material at a mine reclamation site for revegetation purposes will be presented.

Factors used in environmental remedial decision making concerning ecological risk are not well understood or necessarily consistent. Recent Records of Decision (RODs) for Army CERCLA sites were reviewed to select case studies where remedial management occurred in response to ecological risks. Thirty-four Army RODs were evaluated representing decisions promulgated between 1996 and 2004. Five were selected based on assessments that remedial actions were clearly linked to concern for ecological receptors. The Ecological Risk Assessment (ERA) approach and the subsequent risk management process were reviewed for each site. The case studies demonstrated that the ERA findings, as well as critical management decisions regarding interpretation of identified ecological risks, were determinants of remedial action objectives. Decisions regarding the selection of remedial alternatives were based on a set of criteria prescribed by Superfund requirements and guidance. Remedial alternative evaluations require protection of human health and the environment, but protective conditions were determined using different methods at each site. Examining the remedial management process for the 5 case study sites revealed that uncertainty in the risk assessment and decisions regarding appropriate spatial scales for both risk assessment and remediation were important factors influencing remedial action decisions. The case reviews also revealed that levels of documentation were variable from site to site. In the future, more detailed documentation of decision criteria and the development of criteria that consider the resilience of the site will result in more technically defensible ecological risk management.

A Toxicity Identification Evaluation of sediments from various reaches of the Calcasieu Estuary in Louisiana was performed to improve the technical basis for Total Maximum Daily Loads under development for this water body. The Toxicity Identification Evaluation methodology involved manipulations of the physical/chemicalproperties of sediment pore water samples in order to sequentially remove or bind each of the major classes of contaminant compounds and confounding factors. Toxicity tests were performed in conjunction with these manipulations to directly correlate reduction in toxicity with the specifically targeted contaminant classes. Toxicity of sediment porewaters from seven locations was evaluated using the amphipod, Ampelisca abdita and the mysid, Americamysis bahia. Toxicity Identification Evaluation results demonstrated improved survival after filtration, indicating that suspended particulates and associated contaminants were a significant source of toxicity. Subsequent treatments with column extraction and ethylene diamine tetra amino acid reduced toxicity, indicating both organics and metal constituents of pore waters as contributors to toxicity. The analysis of the filters used in the Toxicity Identification Evaluation revealed that particulate copper in the porewater was above criteria values, indicating that adverse exposure potential existed from the particulate phases, and that shifts in partitioning equilibrium could mediate dissolved-phase exposures. The identification of specific contaminant classes as well as particulate effects as sources of acute toxicity from Toxicity Identification Evaluation results indicate that in place sediment contamination as well as pore water flux and resuspension are likely contributors to habitat impairment that should be considered in Total Maximum Daily Load development.