bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of plant and earthworm bioassays to evaluate remediation of soil from a site contaminated with polychlorinated biphenyls
Authors: Meier John R , Chang Lina W , Jacobs Scott , Torsella Joni , Meckes Mark C , Smith M Kate 
Published: March 2010

AbstractSoil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The earthworm toxicity bioassays were the 14-d survival test and 21-d reproduction test, using Lumbricus terrestris and Eisenia fetida andrei. The plant bioassays included phytotoxicity tests for seed germination and root elongation in lettuce and oats, and a genotoxicity test (anaphase aberrations) in Allium cepa (common onion). Although the PCB content of the soil was reduced by 99% (below the remediation goal), toxicity to earthworm reproduction remained essentially unchanged following remediation. Furthermore, phytotoxicity and genotoxicity were higher for the remediated soil compared to the untreated soil. The toxicity remaining after treatment appeared to be due to residual solvent introduced during the remediation process, and/or to heavy metals or other inorganic contaminants not removed by the treatment. Mixture studies involving isopropanol and known toxicants indicated possible synergistic effects of the extraction solvent and soil contaminants. The toxicity in plants was essentially eliminated by a postremediation, water-rinsing step. These results demonstrate a need for including toxicity measurements in the evaluation of technologies used in hazardous waste site remediations, and illustrate the potential value of such measurements for making modifications to remediation processes.
Dietary absorption of sediment-bound fluoranthene by a deposit-feeding gastropod using the 14C:51Cr dual-labeling method
Authors: Forbes Valery E , Forbes Thomas L 
Published: March 2010

Abstract
Polycyclic aromatic hydrocarbons (PAH) constitute a broad class of toxic, environmentally persistent, particle-reactive organic compounds that are ubiquitous in aquatic and terrestrial ecosystems. This study was designed to measure ingestion and dietary absorption of the PAH, fluoranthene, by two genotypes of a deposit-feeding gastropod using the 14C:51Cr dual-labeling method. Sediment processing rate, fluoranthene ingestion rate, selective ingestion of fluoranthene-containing particles, and fluoranthene absorption rate varied as a function of snail body size and genotype. Absorption efficiency of sediment-bound fluoranthene did not vary as a function of body size but differed between genotypes, averaging 42 to 46% for Clone A and 22 to 36% for Clone B. We could detect no significant metabolism of ingested fluoranthene to dissolved organic carbon or CO2 during 24 h following its ingestion. The 14C:51Cr dual-labeling method provides a powerful approach for investigating the dietary absorption of sediment-bound contaminants by (1) allowing the calculation of ingestion selectivity, sediment processing rate, contaminant ingestion rate, and absorption efficiency in individual, small invertebrates; (2) permitting estimation of the fraction of ingested/absorbed contaminant that is metabolized and released via different routes following its ingestion; and (3) facilitating evaluation of the relative importance of porewater versus ingested sediment as routes of contaminant uptake by animals.
Relationship of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran levels to stable-nitrogen isotope abundance in marine birds and mammals in coastal california
Authors: Jarman Walter M , Sydeman William J , Hobson Keith A , Bergqvist Per-Anders 
Published: March 2010

Abstract
Levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in common murre (Uria aalge), Brandt's cormorant (Phalacrocorax penicillatus), rhinoceros auklet (Cerorhinca monocerata), and pigeon guillemot (Cepphus columba) eggs, and Steller sea lion (Eumetopias jubatus) blubber collected from the Gulf of the Farallones National Marine Sanctuary in 1993. In addition, the samples were analyzed for stable-nitrogen isotopes (δ15N). Of the PCDDs and PCDFs, the 2,3,7,8-TCDD (TCDD) and 2,3,7,8-TCDF (TCDF) congeners were the most prominent in the birds. The levels of TCDD in the eggs ranged from 0.2 to 6.6 ng/wet kg in the pigeon guillemot and Brandt's cormorant, respectively. The TCDF ranged from 0.30 to 2.25 ng/kg in the pigeon guillemot and Brandt's cormorant eggs, respectively. Other prominent PCDD and PCDF congeners detected in all bird species were 1,2,3,6,7,8-HxCDD, 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD, and 1,2,3,4,6,7,8-HpCDD. In the Steller sea lion the most prominent congeners were 1,2,3,7,8-PeCDD at 3.2 ng/kg, 2,3,7,8-TCDD at 2.9 ng/kg, OCDF at 2.2 ng/kg, 1,2,3,6,7,8-HxCDD at 1.92 ng/kg, and 1,2,3,4,7,8-HxCDF at 1.3 ng/kg. Stable-nitrogen values ranged from 16.9‰ in the pigeon guillemot and rhinoceros auklet to 19.8% in the Steller sea lion.
Effects of life stage, substrate, and crop position on the exposure and susceptibility of Aphidius rhopalosiphi DeStefani-perez (Hymenoptera: Braconidae) to deltamethrin
Authors: Longley Martin , Jepson Paul 
Published: March 2010

Abstract
Laboratory bioassays were carried out to determine the toxicity of deltamethrin residues to the aphid parasitoid Aphidius rhopalosiphi DeStefani-Perez (Hymenoptera: Braconidae) on glass and foliar substrates. Residual toxicities were compared by iterating sequences of lethal dose ratios between LD10 and LD90 from the dose–response statistics for each substrate. The calculated mean ratios were termed “toxicity factors” (Tf). The Tf values indicated that the toxicity of deltamethrin residues on glass plates was 1.3 times greater than on cereal flag leaves. Parasitoid mortality was reduced by lowering the deltamethrin concentration and parasitoid exposure period. Individuals exposed to field concentrations for less than 1 h recovered when exposure ceased. Parasitoid emergence from hosts was reduced by deltamethrin at field concentrations; however, the fecundity of surviving females did not differ from controls. Deltamethrin applied at half rate had no effect on parasitoid emergence. Spray deposition on aphid mummies within a mature winter wheat canopy varied significantly with leaf position. Mummies located on awns and adaxial surfaces of flag leaves received the highest deposition rates, with the lowest levels recorded for mummies on stems and abaxial leaf surfaces. The low volumes of spray solution impinging upon mummies in the field indicated that current laboratory bioassays may overestimate pesticidal effects on developing parasitoids by between 3.4- and 266-fold.
Comparison of two population-level ecotoxicological endpoints: The intrinsic (r
m) and instantaneous (r
i) rates of increase
Authors: Walthall William K , Stark John D 
Published: March 2010

Abstract
The instantaneous rate of increase (ri) was compared to the intrinsic rate of increase (rm) as an alternative population-level ecotoxicological endpoint. The terrestrial arthropod Acyrthosiphon pisum Harris, the pea aphid, was used as the model species and the new nicotinergic insecticide, imidacloprid, as the xenobiotic. In the first experiment, rm was generated each day from a life table for A. pisum neonates exposed to nontreated (control) potted broad bean, Vicia faba L. (variety Banner), and compared to determine the earliest rm which was not significantly different from the final rm. The rm for neonates introduced to nontreated plants was significantly different on days 6 and 7 but not significantly different between 8 to 40 d postintroduction. A second experiment examined the change in ri over time for neonates introduced at birth to nontreated broad bean and censused at 8, 11, 13, 15, 17, 19, and 21 d postintroduction. The ri for neonate populations introduced to nontreated broad bean peaked on days 11 and 19. The ri on nontreated beans was significantly different (p &lt; 0.05) from rm on days 8 and 15 but not significantly different at 11, 13, 17, 19, and 21 d. A third experiment was conducted comparing rm and ri following 11 d exposure to a range of imidacloprid concentrations applied to broad bean. There was a high correlation (r = 0.91, n = 21, p &lt; 0.01) between ri and rm 11 d after the start of the study, suggesting that ri can be used as a predictive measure in place of rm. There was a negative relationship, y = 0.32 – 0.43x (r2 = 0.88, n = 21), between ri and exposure to imidacloprid-treated broad bean, suggesting that simple regressions may be utilized as tools in the assessment of xenobiotics on population growth rates.
The bioaccumulation of polynuclear aromatic hydrocarbons by benthic invertebrates in an intertidal marsh
Authors: Maruya Keith A , Risebrough Robert W , Horne Alexander J 
Published: March 2010

Abstract
Biota-sediment accumulation factors (BSAF; concentration in organism lipid/concentration in sediment on an organic carbon basis) of polyaromatic hydrocarbons varied with season and along an intertidal gradient in a coastal marsh in San Francisco Bay. The BSAFs were lowest during the local rainy season. During the dry season, BSAFs were lowest in the high intertidal zone closest to shore. Significant differences among species groups were also observed; BSAFs were lowest in polychaetes and highest in the asian clam (Potamocorbula amurensis), varying over almost three orders of magnitude (0.0069-5.4 g sediment organic C/g lipid). The BSAFs decreased with increasing percent fines in the sediments and with PAH concentrations on an organic carbon basis. We suggest that a determining variable is the content of highly aromatic soot particles, which increases during periods of surface runoff and which is expected in the dry season to be highest in the high intertidal zone where these finer particles preferentially accumulate. Correlations of BSAFs with the ratio of the logarithm of the activity coefficients in porewaters to those in sediments were generally stronger than with log Kow, indicating a limitation of octanol as a surrogate for sediment organic carbon or organism lipid. These observations qualify but also strengthen the concept of equilibrium partitioning as the determining factor in bioaccumulation by benthic organisms of nonpolar organic compounds from sediments; the assumption that “organic carbon” can be considered in generic terms without allowance for aromaticity and probably other factors as well, must, however, be reconsidered.
Utility of four strains of white-rot fungi for the detoxification of 2,4,6-trinitrotoluene in liquid culture
Authors: Donnelly Kirby C , Chen Jinchuan C , Huebner Henry J , Brown Kirk W , Autenrieth Robin L , Bonner James S 
Published: March 2010

Abstract
The purpose of this study was to investigate the potential of four different strains of white-rot fungi (Phanerochaete chrysosporium, Phanerochaete sordida, Phlebia brevispora, and Cyathus stercoreus) to degrade 2,4,6-trinitrotoluene (TNT) in liquid medium. Loss of TNT from the culture medium was determined using high-performance liquid chromatography (HPLC), while the mutagenicity of the medium residues was evaluated using the Salmonella/microsome bioassay. The data indicate that within 21 d of incubation, all fungi were able to reduce the TNT concentration (from 90 mg/L) in the liquid medium to below detection limits. In this study, P. sordida showed a relatively high growth rate and the fastest rate of TNT degradation. The fungal treatment also produced a significant reduction of TNT mutagenicity. Treatment with C. stercoreus, P. brevispora, P. sordida, and P. chrysosporium resulted in the elimination of 94%, 90%, 87%, and 67% of the initial TNT-amended medium mutagenicity, respectively. The data also demonstrate that during incubation, TNT was eliminated from the culture medium two to eight times faster than the reduction in mutagenic potential. These results suggest that TNT disappearance alone cannot be used as the sole criterion in TNT remediation. Chemical analysis revealed that the major metabolites in the initial transformation of TNT were the monoamino-dinitrotoluenes, which were also degraded by the selected white-rot fungi. The study demonstrated that the white-rot fungi are capable of metabolizing and detoxifying TNT under aerobic conditions in nonligninolytic liquid medium.
Characterization of metallothionein-like proteins from zebra mussels (Dreissena polymorpha)
Authors: High Kim A , Barthet Veronique J , McLaren James W , Blais Jean-Simon 
Published: March 2010

Abstract
Zebra mussels (Dreissena polymorpha) are freshwater mollusks that have recently infested the Great Lakes ecosystem. Possessing a large capacity for filtration, these mussel populations act as bioconcentrators for contaminants, such as heavy metals, found in the Great Lakes ecosystem. Metallothionein is a low-molecular-weight, heavy metal-binding protein found in most living organisms. Characterization and partial purification of metallothionein-like Cd-binding proteins from zebra mussels were performed. Zebra mussels were exposed to 500 μg/L Cd for 14 d. During the exposure period, two mussels were removed on alternate days for analysis of Cd-binding proteins. Gel-filtration high-performance liquid chromatography-microatomization-atomic absorption spectrophotometry results showed a single Cd-binding molecular weight protein fraction after 2 d of Cd exposure. After 10 d of Cd exposure, however, mussels exhibited an additional, higher molecular weight, Cd-binding protein fraction. The lower molecular weight metallothionein-like Cd-binding protein was further isolated and purified by acetone fractionation, Sephadex G75, and diethylaminoethyl anion-exchange chromatography. The quantities of Zn, Cu, and Cd in the anion-exchange metallothionein-like protein isoforms were determined by inductively coupled plasma-mass spectrometry. The ability to bioconcentrate heavy metals in a metallothionein-like form coupled with their large population in the Great Lakes make zebra mussels suitable for use in a freshwater biomonitoring program for aquatic metal contamination.
A principal-component and least-squares method for allocating polycyclic aromatic hydrocarbons in sediment to multiple sources
Authors: Burns William A , Mankiewicz Paul J , Bence A Edward , Page David S , Parker Keith R 
Published: March 2010

Abstract
A method was developed to allocate polycyclic aromatic hydrocarbons (PAHs) in sediment samples to the PAH sources from which they came. The method uses principal-component analysis to identify possible sources and a least-squares model to find the source mix that gives the best fit of 36 PAH analytes in each sample. The method identified 18 possible PAH sources in a large set of field data collected in Prince William Sound, Alaska, USA, after the 1989 Exxon Valdez oil spill, including diesel oil, diesel soot, spilled crude oil in various weathering states, natural background, creosote, and combustion products from human activities and forest fires. Spill oil was generally found to be a small increment of the natural background in subtidal sediments, whereas combustion products were often the predominant sources for subtidal PAHs near sites of past or present human activity. The method appears to be applicable to other situations, including other spills.
Hydrolytic release of bound residues from composted soil contaminated with 2,4,6-trinitrotoluene
Authors: Thorne Philip G , Leggett Daniel C 
Published: March 2010

AbstractSamples of composted soil were extracted with solvent, then hydrolyzed with acid or base. The concentrations of extractable, unbound 2,4,6-trinitrotoluene and its mono- and diamino metabolites fell rapidly after the first days of composting. Hydrolysis of the extracted residues released significant quantities of intact metabolites.
Interpretation of Microtox® solid-phase toxicity tests: The effects of sediment composition
Authors: Ringwood Amy H , DeLorenzo Marie E , Ross Philippe E , Holland A Fred 
Published: March 2010

Abstract
During pilot year studies for the Estuarine Monitoring and Assessment Program (EMAP) in the Carolinian Province, it was observed that estuarine sediments characterized by high silt-clay content (contaminated as well as uncontaminated) consistently had low Microtox® EC50s (as measured by decreased light production). It was hypothesized that the low EC50 values associated with silty sediments were due to adsorption of the bacteria to the silt-clay particles. During the assay, the bioluminescent bacteria are exposed to a sediment suspension, and the effects on light production are evaluated in the liquid phase that remains after removal of the sediments by filtration. If the bacteria adsorb to the sediments, then the decreased light production observed with silty sediments may be the result of significant bacterial removal, rather than toxicity. This sediment bias could affect the interpretation of results from field studies by overestimating the potential for contaminant effects in muddy areas. We report on studies in which artificial sediments (mixtures of pure sand and clay) were used to evaluate the effects of sediment type (in the absence of contaminants) on Microtox EC50 values and bacterial counts of the liquid phase. The results supported the hypothesis. Microtox EC50s and bacterial concentrations in the liquid phase decreased in a predictable manner as clay composition increased. Methods of normalizing for sediment composition and developing toxicity criteria are discussed.
Bioremediation of TNT-contaminated soil: A laboratory study
Authors: Widrig David L , Boopathy Ramaraj , Manning John F 
Published: March 2010

Abstract
This research presented a bench-scale investigation of an innovative approach to land farming for the bioremediation of 2,4,6-trinitrotoluene (TNT)-contaminated soils. Molasses, which contains sugar, nitrogen, vitamins, and minerals, was used as cosubstrate and this process combines several advantages of conventional land farming with the use of molasses for the biological degradation of TNT and its derivatives. In the optimum treatment, contaminated soil was amended with shredded grass and managed in an operating cycle where it was alternatively flooded with a dilute molasses solution, then drained, passively aerated, and finally tilled when moisture conditions were optimum. Soil TNT concentrations in all treatments receiving molasses were reduced from approximately 4,000-mg/kg levels initially to less than 100 mg/kg in 12 months, and to less than 1 mg/kg in the optimum treatment in this same time. Concentrations of the primary metabolic intermediates and bacterial populations were also tracked. Radiolabeling studies confirmed that the biomass enhanced by the treatments could mineralize approximately 20% of [14C] from a contaminant spike after 22 d. A shredded grass amendment in the optimum treatment was shown to increase moisture retention during aeration phases. The results of this bench-scale study are promising with regard to transferring the process to full-scale applications.
Chironomus tentanslife-cycle test: Design and evaluation for use in assessing toxicity of contaminated sediments
Authors: Benoit Duane A , Sibley Paul K , Juenemann Jamie L , Ankley Gerald T 
Published: March 2010

AbstractThe development and standardization of toxicity test methods for assessing toxicity of contaminated freshwater sediments has focused predominantly on short-term exposures and lethality. In many situations, however, toxicity is more likely to become manifest over long periods of time so there is need for standardized testing procedures by which sublethal sediment toxicity can be adequately assessed. In this study, we present and evaluate a new life cycle test, using the midge Chironomus tentans, which enables the assessment of sublethal toxicity of contaminated sediments. In designing the life cycle test, our goal was to make the assay relatively straightforward and, to the extent possible, methodologically compatible with the standard 10-d test. The test is initiated with newly hatched (&lt;24 h) larvae and uses four effects-based endpoints to assess toxicity: survival, growth, emergence, and reproduction. Survival is determined at 20 d and at the end of the test by back-calculating through emergence data. Growth can be determined at 20 d, which corresponds to the 10-d endpoint in the 10-d C. tentans growth test initiated with 10-d-old larvae. From day 23 to the end of the test, emergence and reproduction are monitored daily. The number of eggs per female is determined for each egg mass, which is then incubated for 6 d to determine hatching success. Each treatment in the life cycle test is terminated separately after 7 consecutive days without emergence. We evaluated the life cycle test by following one generation of C. tentans in sediments collected from the upper Mississippi River. Survival of larvae exceeded 90% at 20 d. Of these larvae, between 60 and 70% successfully emerged; survivorship among pupae and adults exceeded 85%. Mean egg production ranged from 906 to 1,107 eggs per female. The test required 65 d to complete, including pretest preparation. These data show that the C. tentans life cycle test can be used to assess sublethal toxicity accurately in contaminated sediments and provides a suitable compliment to the standard C. tentans 10-d test.
Cadmium binding in the blood plasma of two marine bivalves
Authors: Robinson William E , Ryan David K , Sullivan Patricia A , Boggs Colleen C 
Published: March 2010

Abstract
Cadmium tansport in the plasma of Mytilus edulis L. displays attributes similar to those previously described for Mercenaria mercenaria (L.). The majority of Cr, Cu, Ni, and Zn is partitioned in the plasma rather than the hemocytes in both species, although differences in Fe and Mn are apparent. Mussels however contain twice the number of circulating hemocytes (2.1 ± 0.8% of whole blood weight; n = 75 vs 1.2 ± 0.3%; n = 70 for the quahog) and approximately three times more plasma protein than the quahog. Titration experiments using ion-specific electrode (ISE) measurements and equilibrium dialysis (ED) experiments indicate that both species have a low-affinity, high-capacity system for the internal transport of Cd. At low blood Cd concentrations (&lt;8.9 μM) and short dialysis times (24 h), approximately 90% of the Cd in mussel plasma is bound to plasma proteins. At higher Cd concentrations and at longer dialysis times, the percentage of free Cd increases substantially. The Cd affinity was slightly lower in mussel plasma compared to the quahog (log10K = 2.6–3.9/M vs 3.7–4.3/M), and mussel plasma CL values were appreciably lower (0.16–1.11 mmol/g protein) than those for the quahog (1.97–2.26 mmol/g protein). Both ISE and ED experiments on quahog plasma yielded similar estimates of K and CL.