bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterizing aquatic ecological risks from pesticides using a diquat dibromide case study. I. Probabilistic exposure estimates
Authors: Ritter Amy M , Shaw Jennifer L , Williams W Martin , Travis Kim Z 
Published: March 2010

Abstract
Diquat dibromide (6,7-dihydrodipyrido[1,2-a:2′,1′-c] pyrazinediium dibromide; diquat) is one of the few herbicides registered for direct application to water systems in the United States to control noxious aquatic weeds. The dissipation of diquat dibromide in aquatic environments is highly dependent on the hydrodynamic and physicochemical characteristics of the receiving water body. Computer simulations (EXAMSII) were conducted to evaluate the variability of diquat cation dissipation in farm ponds, lakes, and canals following applications to control aquatic weeds across the United States. Within each scenario, probabilities were assigned to varying values for physical properties (velocity, dispersion, suspended sediment concentrations, bed sediment properties, and plant biomass) using a joint probability method, and the results were expressed as spatially and temporally explicit cumulative probability distributions by water-body type on a regional scale. The results showed that the dissipation of diquat cation in water was very rapid, with the highest exposure concentrations (90th percentile) predicted to be 0.194 mg/L diquat cation 1 h after treatment and typically reaching 0.01 mg/L by 96 h.
Biosensing the acute toxicity of metal interactions: Are they additive, synergistic, or antagonistic?
Authors: Preston Sara , Coad Nicholas , Townend John , Killham Ken , Paton Graeme I 
Published: March 2010

AbstractThe toxicity of Zn, Cu, and Cd, alone or in combination, was assessed using two luminescence-based microbialbiosensors from different ecological niches: Escherichia coli HB101 pUCD607 and Pseudomonas fluorescens 10586 pUCD607. Significant synergistic interactions occurred between the toxic effects of the Zn and Cu and Zn and Cd combinations and the response of E. coli (i.e., toxicities of combinations of pollutants were greater than predicted from addition of individual toxicities). Significant synergistic interactions were also observed between the toxicities of Cd and Cu combinations and the response of P. fluorescens. A longer exposure time was shown to significantly increase the sensitivity of E. coli to the metal pollutants. P. fluorescens was observed to significantly decrease in its sensitivity toward Zn and Cd with a longer exposure time. It was shown that the toxicity of combinations of metals could not be modeled on the basis that their toxic action was independent of each other. The application of different models to describe interactions between combinations of metals is discussed. The importance of considering the test species and the exposure period selected for toxicity assessment was highlighted, as was the need to further investigate the toxicity of combinations of pollutants.
Metabolism and environmental degradation of pyrethroid insecticides produce compounds with endocrine activities
Authors: Tyler Charles R , Beresford Nicola , van der Woning Melanie , Sumpter John P , Tchorpe Kcaren 
Published: March 2010

AbstractPyrethroids are semisynthetic derivatives of the chrysanthemumic acids that have been developed as insecticides, and they are in widespread use. Considerable information is available regarding the toxicity, metabolism, and environmental degradation of pyrethroids, but almost nothing is known about their interactions with hormone receptors. In this study, seven commercial pyrethroids as well as products of metabolism and environmental degradation of permethrin were tested for steroid activity (both as agonist and as antagonist) in recombinant yeasts expressing the human estrogen and human androgen receptors. Pyrethroid insecticides had steroid receptor–binding activity. Fenpropathrin and permethrin both acted as weak estrogen agonists. Allethrin, bioallethrin, and cypermethrin had antiestrogenic activity, with potencies between 1,000-fold (bioallethrin) and 10,000-fold (allethrin) less than the established antiestrogen 4-OH-tamoxifen. Six of the seven pyrethroids tested had antiandrogenic activity (the most active, bioallethrin, was 70-fold less potent than flutamide). These activities, however, are believed to result either from contaminants/degradation products in the parent compounds or from metabolism of the parent compounds into active metabolites by the yeast. Three derivatives of permethrin all interacted with sex steroid hormone receptors. Three-phenoxybenzyl alcohol had both estrogenic and antiandrogenic activity, with potencies more than 100-fold greater than that of the parent compound, permethrin. Three-phenoxybenzoic acid and the cyclopropane acid derivative both had antiestrogenic activity, with approximately 100-fold and 1,000fold lower potencies than 4-OH-tamoxifen, respectively. The data presented here highlight that an understanding of the metabolism and environmental degradation of chemicals is essential for assessing the potential of chemicals to have endocrine-modulating effects.
Transformation of trinitrotoluene to triaminotoluene by mixed cultures incubated under methanogenic conditions
Authors: Hwang Philip , Chow Teresa , Adrian Neal R 
Published: March 2010

Abstract
2,4,6-Trinitrotoluene (TNT) is an explosive widely used by the military. Although it is no longer manufactured in the United States, large amounts of wastewater are generated annually from load, assembly, packing, and demilitarization operations. Granular-activated carbon adsorption is the standard technology for treating wastewater containing TNT and maintaining discharges within the limits established under the National Pollutant Discharge Elimination System. Studies evaluating biological treatment of pink water with an anaerobic fluidized-bed, granular-activated carbon bioreactor have been promising, but the fate of TNT is unknown. We investigated the anaerobic transformation of TNT by biofilm microorganisms obtained from a wastewater treatment plant receiving explosive manufacturing wastewater. The TNT was transformed to a mixture of 2-amino-4,6-dinitrotolune; 4-amino-2,6-dinitrotoluene; 2,4-diamino-6-nitrotoluene; and 2,6-diamino-4-nitrotoluene before culminating in the formation of triaminoto-luene (TAT). Triaminotoluene was susceptible to further degradation under anaerobic conditions, but its fate was not determined. Methane formation was inhibited but resumed after the depletion of the diaminonitrotoluene isomers. These studies demonstrate near stoichiometric formation of TAT from TNT and the transformation of 2-amino-4,6-dinitrotoluene to 2,4-diamino-6-nitrotoluene and 2,6-diamino-4-nitrotoluene by a mixed culture incubated under methanogenic conditions. This evidence indicates TAT is also a likely end-product of TNT biodegradation in the anaerobic fluidized bed bioreactor.
Adrenocorticotrophin- and cyclic adenosine 3′,5′-monophosphate-stimulated cortisol secretion in interrenal tissue of rainbow trout exposed in vitro to DDT compounds
Authors: Benguira Sandrine , Hontela Alice 
Published: March 2010

Abstract
The effects of DDT compounds on the function and viability of interrenal corticosteroidogenic tissue were investigated in vitro in rainbow trout (Oncorhynchus mykiss) in a dose–response study. The o,p′-dichlorodiphenyldichloroethane (DDD) was the most potent of the tested chemicals in decreasing adrenocorticotropic hormone (ACTH)-stimulated cortisol secretion by head kidney fragments compared with controls. The dbcAMP-stimulated cortisol secretion was also impaired with doses of 50 and 100 mg/L o,p′-DDD but not 25 mg/L. Tissue viability, estimated by the release of lactate dehydrogenase (LDH), was similar to controls at 25 mg/L and was decreased significantly at 50 and 100 mg/L o,p′-DDD. These results suggest that o,p′-DDD is an adrenotoxic compound that may disrupt the 3′,5′-monophosphate (cAMP) generation step and, at higher doses, induce irreversible cytotoxic effects. The p,p′-DDT induced a significant inhibition in the secretory response to ACTH and dbcAMP only at 100 mg/L, while p,p′-DDD had no effect on the cortisol secretion. A significantly decreased viability was detected at the higher doses of p,p′-DDT and p,p′-DDD without a detectable disruption of cortisol synthesis. The steroidogenic interrenal cells may be less sensitive to the DDT compounds tested than other cell populations within the teleost head kidney.
Analysis of organochlorine compounds and extractable organic halogen in three subspecies of ringed seal from Northeast Europe
Authors: Kostamo Auli , Medvedev Nikolai , Pellinen Jukka , Hyvärinen Heikki , Kukkonen Jussi V K 
Published: March 2010

Abstract
Oganochlorine compounds in blubber samples of the ringed seal (Phoca hispida saimensis, P. h. ladogensis, and P. h. hispida) were analyzed in order to estimate the state of pollution in three different water areas in Northeast Europe, namely, Lake Saimaa in Finland, Lake Ladoga, and the White Sea in Russia. Geographic differences in concentrations and in relative concentrations of tri- and tetrachlorocymenes, hexachlorobenzene, α-HCH, β-HCH, -γ-HCH (Lindane), seven polychlorinated bi-phenyl (PCB) congeners, and p,p′-DDT and its metabolites in ringed seals were compared. Concentrations of chlorinated hydrocarbons varied between the water areas. The highest concentrations were found in Saimaa ringed seals, followed by Ladoga ringed seals, and the lowest concentrations were detected in ringed seals from the White Sea. Extractable organic halogen (EOX) concentrations in blubber were also analyzed. The concentrations showed a geographic trend similar to those for the individual compounds identified. In Lakes Ladoga and Saimaa, the concentrations of EOX and chlorinated hydrocarbons in the blubber were dependent on the age and sex of the seals, but no such relationship was observed in samples from the White Sea.
Incidence and impact of axial malformations in larval bullfrogs (Rana catesbeiana) developing in sites polluted by a coal-burning power plant
Authors: Hopkins William A , Congdon Justin , Ray John K 
Published: March 2010

Abstract
Amphibian malformations have recently received much attention from the scientific community, but few studies have provided evidence linking environmental pollution to larval amphibian malformations in the field. We document an increased incidence of axial malformations in bullfrog larvae (Rana catesbeiana) inhabiting two sites contaminated with coal combustion wastes. In the polluted sites, 18 and 37% of larvae exhibited lateral curvatures of the spine, whereas zero and 4% of larvae from two reference sites had similar malformations. Larvae from the most heavily polluted site had significantly higher tissue concentrations of potentially toxic trace elements, including As, Cd, Se, Cu, Cr, and V, compared with conspecifics from the reference sites. In addition, malformed larvae from the most contaminated site had decreased swimming speeds compared with those of normal larvae from the same site. We hypothesize that the complex mixture of contaminants produced by coal combustion is responsible for the high incidence of malformations and associated effects on swimming performance.
Ecotoxicologic change at a remediated superfund site in San Francisco, California, USA
Authors: Anderson Brian S , Hunt John W , Phillips Bryn M , Stoelting Matt , Becker Jonathon , Fairey Russell , Puckett H Max , Stephenson Mark , Tjeerdema Ronald S , Martin Michael 
Published: March 2010

AbstractLauritzen Channel is an industrial waterway adjacent to the former United Heckathorn facility in the inner Richmond Harbor area of San Francisco Bay, California, USA. Marine sediments at this Superfund site were dredged from late 1996 through early 1997 to remove the primary chemicals of concern: DDT, and dieldrin. This study assessed the Lauritzen Channel marine environment immediately before and approximately one year after the dredging of sediments. The study included chemical analysis of sediments, tissue concentrations of transplanted mussels, toxicity testing of sediment samples, and characterization of benthic community structure. Results indicated that sediment toxicity to bivalve larvae (Mytilus galloprovincialis) decreased in postre-mediation samples, but that toxicity to the amphipod Eohaustorius estuarius increased significantly. Assessment of benthos at this site suggested a transitional benthic community structure. In addition, postremediation sediments remained contaminated by a variety of organic chemical compounds, including DDT, dieldrin, chlordane, polycyclic aromatic hydrocarbons, and polychlorinated bi-phenyls. Tissue concentrations of DDT and dieldrin in mussels (M. galloprovincialis) were lower than those in preremediation samples, indicating that although sediment concentrations of organochlorine pesticides remained high, concentrations of these chemicals in the water column were reduced after dredging. This study demonstrates that the components of the site assessment were useful in determining effectiveness of the remediation activities.
Uptake of trichloroethylene by hybrid poplar trees grown hydroponically in flow-through plant growth chambers
Authors: Orchard Brady J , Doucette William J , Chard Julie K , Bugbee Bruce 
Published: March 2010

Abstract
Phytoremediation is being promoted as a cost-effective treatment option for shallow groundwater and soils contaminated with trichloroethylene (TCE). However, its effectiveness is difficult to assess due to contradictory reports regarding the magnitude of plant uptake and phytovolatilization. Experimental artifacts and plant stress, resulting from the use of static or low-flow plant growth laboratory systems, may account for part of the discrepancy. High exposure concentrations and short durations may also cause artifacts in laboratory studies. A dual-chamber plant growth system designed to minimize experimental artifacts was used to determine the uptake of [14C] TCE by hydroponically grown hybrid poplar as a function of plant stress (aerobic and oxygen-reduced root zone), exposure concentration (1–70 mg/L), and exposure duration (12 or 26 d). The [14C]TCE recoveries ranged from 92 to 101% in 11 dosed chambers. Trichloroethylene mass equivalent concentrations in the shoot tissue (2–168 mg/kg) were dependent on the amount of water transpired and the exposure concentration. Root-zone oxygen status did not significantly impact TCE uptake. Transpiration stream concentration factors (TSCFs) determined in these studies (0.02–0.22) were independent of exposure duration and are much lower than those previously reported and predicted. The role of TSCF and other factors in estimating the significance of plant uptake in the phytoremediation of TCE-contaminated groundwater is discussed.
Avoidance of aluminum by rainbow trout
Authors: Exley Christopher 
Published: March 2010

Abstract
Aluminum is the principal toxicant in fish in acid waters. The ability to avoid Al, particularly at low concentrations, would confer a considerable ecological advantage, but previous research into avoidance of Al has produced mixed results. I used a cylindrical perspex tank, 150 cm in length, to study avoidance of Al by rainbow trout fry. The fish avoided Al, and their response was dependent on pH. Avoidance that was demonstrated at pHs of 5.00, 5.50, and 5.75 was abolished at a pH of 6.00. Fry avoided very low Al concentrations, being sensitive to [Al] &gt; 1.00 μmol L−1 at a pH of 5.00. This unequivocal demonstration of avoidance by rainbow trout fry of Al may have important implications for the ecology of indigenous fish populations in surface waters impacted by acidic deposition.
Nonylphenols in sediments and effluents associated with diverse wastewater outfalls
Authors: Hale Robert C , Smith Craig L , de Fur Paul O , Harvey Ellen , Bush Elizabeth O , La Guardia Mark J , Vadas George G 
Published: March 2010

Abstract
Nonylphenols (NPs) have been reported to disrupt endocrine function and sexual development in aquatic organisms at low concentrations. Environmental NP burdens are predominantly derived from degradation of nonylphenol polyethoxylate surfactants. We detected NPs in discharge-associated riverine sediments adjacent to 11 of 20 active sewage treatment plants (STPs) at concentrations up to 12,400 μg/kg. While most previous studies have focused on STPs, nonylphenols were observed in association with a variety of outfall types. The highest sediment burden, 14,100 μg/kg, was detected near a federal facility's stormwater discharge. Of 75 sediments examined from 67 sites, 45% contained NP concentrations &gt;5 μg/kg; median concentration in these NP-positive sediments was 369 μg/kg. Other surfactant-derived alkylphenolic compounds, specifically 4-tert-octylphenol and 4-cumylphenol, were observed in two sediments at 8,220 and 70,000 μg/kg, respectively. The maximum NP concentration detected in an effluent, 6,300 μg/L, was from a shipyard oil/water separator. Nonylphenols were detected (&gt; 1.0 μg/L) in 20% of the 59 effluents examined; 10% exceeded 10 μg/L. Sediments sampled near a STP that had ceased treatment operations 20 years prior contained 54,000 μg/kg, indicative of long-term NP residence. Results indicate that NPs may be released from diverse sources, concentrate in associated sediments, and persist therein for extended periods.
Toxicokinetics of polycyclic aromatic hydrocarbons inEisenia andrei(Oligochaeta) using spiked soil
Authors: Jager Tjalling , Sánchez Francisco A. Antón , Muijs Barry , van der Velde Els G , Posthuma Leo 
Published: March 2010

AbstractThe accumulation of four polycyclic aromatic hydrocarbons ([PAHs]; phenanthrene, pyrene, fluoranthene, and ben-zo[a]pyrene) was tested in the earthworm Eisenia andrei in a spiked artificial soil medium. A typical peak in the body residues was observed for all PAHs around day 7, which could not be explained from changes in the total soil concentration. It is argued that the most likely cause of this peak is a decrease in the concentration in pore water, the main bioavailable phase for earthworms. This decrease is caused by biodegradation while the low rate of mass transfer from the solid state precludes replenishment. To describe the data, bioavailability was assumed to decline exponentially in time, but the shape of the accumulation curves suggests a more abrupt change. Estimates of the uptake rate (k1) are similar for all PAHs when expressed on soil solution basis (approximately 2,000 L/kg/d); the elimination rate (k2) shows a decrease with Kow as expected, but the values tend to be slightly lower than literature data. The dynamic bioconcentration factors (k1/k2) agree well with an equilibrium partitioning between soil water and the phases inside the organism.
Contribution of trace metals in structuring in situ macroinvertebrate community composition along a salinity gradient
Authors: Peeters Edwin T.H.M. , Gardeniers Jean JP , Koelmans Albert A 
Published: March 2010

Abstract
Macroinvertebrates were studied along a salinity gradient in the North Sea Canal, The Netherlands, to quantify the effect of trace metals (cadmium, copper, lead, zinc) on community composition. In addition, two methods for assessing metal bioavailability (normalizing metal concentrations on organic carbon and on the smallest sediment fraction) were compared. Factor analyses showed that normalizing trace metals resulted in an improved separation of trace metals from ecological factors (depth, organic carbon, granulometry, and chloride). The variation in the macroinvertebrate data was partitioned into four sources using partial canonical correspondence analysis, with the partitions being purely ecological factors, purely trace metals, mutual ecological factors and trace metals, and unexplained. Partial canonical correspondence analysis applied to total and normalized trace metal concentrations gave similar results in terms of unexplained variances. However, normalization on organic carbon resulted in the highest percentage of variation explained by purely ecological factors and purely trace metals. Accounting for bioavailability thus improves the identification of factors affecting the in situ community structure. Ecological factors explained 45.4% and trace metals 8.6% of the variation in the macroinvertebrate community composition in the ecosystem of the North Sea Canal. These contributions were significant, and it is concluded that trace metals significantly affected the community composition in an environment with multiple stressors. Variance partitioning is recommended for incorporation in further risk assessment studies.
Challenges in forecasting the long-term impacts of multiple stressors on a mid-Atlantic region, USA
Authors: Carpenter Dean E , Lunetta Ross S 
Published: March 2010

Abstract
The U.S. Environmental Protection Agency, Office of Research and Development, has selected a multistate region in the mid-Atlantic as a pilot location for its regional vulnerability assessment initiative. The study included an initial problem-formulation (hazard-identification) phase conducted in consultation with local stakeholders. Nine ecological hazard (stressor) categories were selected for study based on scientific criteria and resource limitations. Initial products included one or more stressor data sets (profiles) for each hazard category, which represented an initial attempt at creating a continuous baseline database necessary for subsequent ecosystem exposure assessment. Stressor profiles were developed from the interpolation of monitoring network point data, modeling forecasts, and the processing of continuous data sets. Disparate data resolutions and temporal inconsistences among profiles will require that uncertainties for each profile be documented during multiple stressor analysis. Such uncertainties in data quality must be effectively portrayed to illustrate how they can limit profile utility during quantitative exposure analysis. Current research efforts have focused on the identification of ecosystem receptor endpoints of critical importance to maintaining ecosystem function in the mid-Atlantic. This research includes the establishment of stressor–receptor exposure period, magnitude, and duration of biological importance in an initial survey-level analysis to support the selection of stressors and receptors for exposure assessment analysis. Subsequent to this selection process, receptor data sets will be assembled at appropriate spatial and temporal resolutions commensurate with the exposure pathway processes of interest. Exposure profiles will be developed based on the cooccurrence of both stressor and receptor in both space and time required to represent a biologically significant exposure.