bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of pesticides on songbird productivity in conjunction with pecan cultivation in southern georgia: A multiple-exposure experimental design
Authors: Patnode Kathleen A. , White Donald H. 
Published: March 2010

Abstract
A prototypic experimental design was used to assess sublethal effects of multiple and varied organophosphates and carbamates on reproduction in birds. The design allowed for classification of pesticide exposure according to toxicity of applied compounds and type and frequency of applications. Daily survival rates (DSRs) of nests, eggs, and nestlings were determined for northern mockingbirds (Mimus polyglottos), brown thrashers (Toxostoma rufum), and northern cardinals (Cardinalis cardinalis) nesting along edges of pecan orchards and row crops in southern Georgia. Egg and nestling DSRs for all species combined varied inversely (P &lt; 0.05) with exposure. Nestling weight gain was reduced (P &lt; 0.05) with increasing exposure levels in northern mockingbirds and brown thrashers. Parenting behavior in northern cardinal and northern mockingbird did not differ (P &gt; 0.05) among three exposure levels. Brain cholinesterase activities were age-dependent and substantiated adult, but not nestling, exposure. Results suggest that increasing exposure to pesticides may reduce songbird productivity.
Integrity of five granular insecticide carriers in house sparrow gizzards
Authors: Best Louis B. , Gionfriddo James P. 
Published: March 2010

Abstract
This study evaluated the integrity of five granular insecticide carriers in gizzards of house sparrows (Passer domesttcus). Bentonite clay and gypsum granules disintegrated very rapidly in gizzards, heat-treated clay and corncob particles were retained in gizzards for several hours, and silica granules were the most persistent. Granule integrity may influence granule consumption rates and thus should be considered in assessments of avian exposure to granular insecticides.
Assessing the toxicity of freshwater sediments
Authors: Burton G. Allen 
Published: March 2010

Abstract
The science of sediment toxicology essentially began in the late 1970s. It was largely a product of dredging concerns and recognition of widespread contamination of sediments. During the past few years, sediment toxicity research activity has increased dramatically. Currently, most tests are of an acute nature with fewer available for determining sublethal endpoints of chronic toxicity. Test systems of single and multiple species have included most levels of biological organization in aquatic ecosystems and have been conducted in the laboratory on whole sediments, interstitial waters, elutriates, or other extractable fractions under a wide variety of conditions. Evaluations of methodological effects and comparisons with in situ toxicity using surrogate test species and indigenous communities have, on occasion, shown significant differences in test responses. These differences may be attributed to laboratory-controlled parameters (e.g., light, species, life stage, exposure conditions, test phase, spiking method); sampling and laboratory-induced disruption of sediment integrity; alteration of toxicant partitioning due to manipulations and temporal effects; and failure to recognize other influencing ecosystem variables (e.g., organism niche and life cycle, sediment partitioning and gradient dynamics, physicochemical and biological process integration, biotic and abiotic disturbances, micro- and macrobiota patches, food-web interactions). Optimizing and standardizing test methods will require further studies of these variables to improve inter-laboratory comparisons and ecosystem validity. Despite the many unknowns that exist, a variety of sediment toxicity tests have been effectively used in assessing toxicant contamination by measuring the bioavailable fraction of the in-place pollutants. The optimal assays vary with the study and its objectives. Intergrative studies using several chemical, community, and toxicity measures are currently the most effective at defining ecosystem perturbations.
Experimental designs for aquatic mesocosm studies: A comparison of the “anova” and “regression” design for assessing the impact of tetrachlorophenol on zooplankton populations in limnocorrals
Authors: Liber Karsten , Kaushik Narinder K. , Solomon Keith R. , Carey John H. 
Published: March 2010

Abstract
Two experimental designs were compared for assessing the impact of a commercial 2,3,4,6-tetrachlorophenol formulation (DIATOX®) on zooplankton abundance in a set of limnocorrals. The first design, based on blocked analysis of variance (ANOVA) procedures, used treatments of 0, 0.75, and 1.50 mg/L DIATOX with three replicates of each. The second design, based on regression procedures, had eight treatments ranging from 0 to 7.3 mg/L DIATOX with no replication.
For the ANOVA experiment, a conventional ANOVA by day revealed significant impact on all zooplankton taxa investigated. Impact and time to recovery were greater with the 1.50-mg/L DIATOX treatment, and rotifers were more sensitive than macrozooplankton. A repeated-measures ANOVA, used to correct for pretreatment variability, revealed additional differences as significant. The ANOVA design permits easy assessment of impact at the chosen toxicant levels, but no conclusion can be drawn regarding the no-effect concentration (NEC) for major zooplankton taxa.
For the regression experiment, linear dose—response relationships were used to estimate the NEC by inverse regression analysis. NECs for major zooplankton taxa and dominant species ranged from 0.28 mg/L DIATOX for immature Copepoda to 0.50 mg/L DIATOX for combined Cladocera. In 9 of 14 cases, however, the estimated EC50 ≤ NEC, an indication that an increased number of lower test concentrations were needed. The regression design offers a promising alternative to the common ANOVA design and allows for the estimation of specified end points such as the NEC and EC50.
Use and efficiency of ethylene glycol monomethyl ether and monoethanolamine to trap volatilized [7-14C]naphthalene and 14CO2
Authors: Abbott C. K. , Sims R. C. , Sorensen D. L. 
Published: March 2010

Abstract
Separation of radiolabeled CO2 from volatile parent compound(s) or degradation products in air from biodegradation microcosms has been done by using solubility in alkaline vs. nonpolar solvents or solutions. However, trapping solvents or solutions used to collect radiolabeled CO2 may absorb some volatile intermediate products or the volatilized parent compound. Similarly, solvents used to trap volatile radiolabeled degradation intermediates or volatile parent compound may absorb some radiolabeled CO2. If this lack of absorption specificity is significant, the clear interpretation of radioactivity-counting analyses may be compromised.
A procedure designed to separate volatilized [7-14C]naphthalene and 14CO2 from the same air stream was evaluated for its efficiency. Ethylene glycol monomethyl ether (EGME) effectively trapped naphthalene (98.6% recovery) but retained approximately 0.8% of the 14CO2, whereas monoethanolamine (MEA):methanol:scintillation cocktail solution trapped approximately 99.5% of the naphthalene and virtually 100% of the CO2. Preliminary studies of the efficiency of trapping solutions for parent compounds and mineralized CO2 should be made before conclusions are made concerning the extent or rate of mineralization based on the amount of radiolabeled carbon retained in a trapping solution.
The influence of organic matter quality on the toxicity and partitioning of sediment-associated fluoranthene
Authors: Dewitt Theodore H. , Jones Jill K.P. , Ozretich Robert J. , Swartz Richard C. , Lamberson Janet O. , Schults Donald W. , Ditsworth George R. , Smith Lawrence M. , Hoselton Laura 
Published: March 2010

Abstract
Organic matter in sediment is derived from many sources, including dead plants and animals, fecal matter, and flocculated colloidal organic matter. Chemical partitioning and toxicity of nonpolar organic contaminants is strongly affected by the quantity of sediment organic matter. The purpose of this study was to determine whether the quality of sediment organic matter affects partitioning and bioavailability of such contaminants.
A base substrate, amended to a consistent organic carbon level (nominally 0.4%, measured 0.35% ± 0.11 sd POC [particulate organic carbon]) with five types of organic matter (a macrophyte, fecal matter of two invertebrate species, suspended particulate organic matter, and an organic-rich mud), was spiked with serial concentrations of the polynuclear aromatic hydrocarbon, fluoranthene. After a five-week equilibration period, the toxicity of the spiked substrates to an infaunal amphipod, Rhepoxynius abronius, was measured, and the distribution of fluoranthene between particulate and interstitial water phases (including total and freely dissolved interstitial water phases) was determined.
The range of acute toxicity among organic matter–source treatments was small when based on total sediment concentrations (11.1–19.1 mg fluoranthene per kilogram dry sediment, nominal). Partitioning of fluoranthene between particulate-sorbed and interstitial water phases was not affected by organic matter quality, except when the source was fresh plant material. This variability may have been due to qualitative differences in the particulate/interstitial water partitioning in plant material as a source of sedimentary organic matter or an artifact in the method used to determine freely dissolved, interstitial water fluoranthene concentrations. Equilibrium partitioning models accurately predicted interstitial water concentrations of fluoranthene for the nonplant substrates once corrections were made for the solubility of fluoranthene in seawater. Our data suggest that equilibrium partitioning–based sediment quality criteria for fluoranthene may not need to correct for the quality of organic carbon in sediments and that these criteria can be applied to sediments with a particulate organic carbon content as low as 0.3%.
An example of the identification of diazinon as a primary toxicant in an effluent
Authors: Amato Joseph R. , Lukasewycz Marta T. , Robert Eric D. , Mount Donald I. , Durhan Elizabeth J. , Ankley Gerald T. 
Published: March 2010

AbstractA toxicity identification evaluation (TIE) conducted on a municipal wastewater discharge from the southeast United States was part of a research project aimed at developing U.S. Environmental Protection Agency (EPA) TIE methods for acutely toxic effluents. The effluent consistently exhibited acute toxicity to Ceriodaphnia dubia but not to fathead minnows (Pimephales promelas). Toxicity characterization procedures revealed that the primary toxicant was a nonpolar organic. Toxicity was recovered through C18 solid-phase extraction and concentration steps. Gas chromatography–mass spectroscopy of these concentrates revealed the presence of diazinon (O, O-diethyl O-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] phosphorothioate). Diazinon concentrations in whole effluent, determined by GC analyses, correlated well with the toxicity measurements of each sample. Relative species sensitivity also implicated diazinon as the primary toxicant. This study illustrates the successful application of EPA TIE methodologies for identifying a nonpolar organic toxicant in a complex effluent. The significance of detecting diazinon at acutely toxic concentrations in municipal wastewater may indicate a more widespread problem in this region of the United States. This toxicity problem may be attributed to the chemical characteristics of diazinon and its applications.
Testing sediment toxicity in chesapeake bay with the amphipod Leptocheirus plumulosus: An evaluation
Authors: Schlekat Christian E. , Mcgee Beth L. , Reinharz Eli 
Published: March 2010

Abstract
Organisms selected for testing the toxicity of estuarine sediments must exhibit sensitivity to toxicants while remaining tolerant of wide ranges of salinities and sediment characteristics. The amphipod Leptocheirus plumulosus Shoemaker is an ecologically important infaunal inhabitant of Chesapeake Bay sediments. Leptocheirus plumulosus was exposed to a range of salinities and sediments varying in physical composition for up to 28 d in separate experiments to determine effects of natural environmental variables on amphipod survival and reproduction. No significant differences in adult survival were observed among salinity treatments ranging from 1.5 to 32 ppt or among sediment treatments varying in particle size and organic content. Significant effects on reproductive end points were detected, indicating the potential for incorporating sublethal end points into the bioassay. Acute 96-h LC50 values for aqueous cadmium at a salinity of 6 ppt were determined for Leptocheirus plumulosus and the amphipod Hyalella azteca Saussure, an organism commonly used in freshwater sediment toxicity tests. The LC50 values were 0.30 mg Cd per liter and 0.19 mg Cd per liter for Leptocheirus plumulosus and Hyalella azteca, respectively.
Assessment of methods for estimating ecological risk in the terrestrial component: A case study at the baird & mcguire superfund site in holbrook, massachusetts
Authors: Menzie Charles A. , Burmaster David E. , Freshman Jonathan S. , Callahan Clarence A. 
Published: March 2010

Abstract
Predictive, bioassay, and field methods were compared with regard to assessing conditions and risks to terrestrial biota at a Superfund site contaminated with pesticides. Research indicated that predictive methods could result in large uncertainties, especially when attempting to estimate food chain transfer from soil to higher trophic levels (birds and mammals). Of the examined predictive methods, the soil-to-earthworm model yielded results that agreed best with field observations and literature values. Laboratory and in-field bioassays on soils provided good information on the potential toxicity of soils and the potential for bioaccumulation. In-field bioassay tests with earthworms were useful for defining the spatial distribution of toxic soils at the site as well as for indicating potential bioaccumulation in invertebrates. An attractive feature of in-field bioassays is that samples do not have to be removed from the field and assessments can begin to be made in the field. The importance of performing reality checks by conducting field studies was clearly demonstrated in our study with regard to the soil invertebrate community as well as birds and mammals. The main advantage of the field studies is that they provide direct information on conditions and thus aid in the interpretation or application of laboratory data. Difficulties were encountered in the conduct of population studies of the birds and mammals. Therefore, although site surveys of birds and mammals provide gross indications as to the presence and diversity of animals, it is probably more useful to rely on measures of residues and biomarkers to assess potential exposures and the possibility of subtle effects. Overall, it appears that ecological risk assessments at Superfund sites are best conducted by using a mix of predictive, laboratory, and field methods.
Application of QSARs, extrapolation and equilibrium partitioning in aquatic effects assessment. I. Narcotic industrial pollutants
Authors: Van Leeuwen Cees J. , Van Der Zandt Peter T. J. , Aldenberg Tom , Verhaar Henk J.M. , Hermens Joop L.M. 
Published: March 2010

Abstract
Quantitative structure–activity relationship (QSAR) estimates of toxicity of narcotic chemicals for 19 species of bacteria, algae, fungi, protozoans, coelenterates, rotifers, molluscs, crustaceans, insects, fish, and amphibians were used to predict no-effect levels (NELs) at the ecosystem level by means of recently developed extrapolation methods. Equilibrium partitioning theory was used to derive NELs for aquatic sediments and internal toxicant concentrations for aquatic organisms. A simple table is given from which NELs for narcotic chemicals for water, sediment, and residues in biota can be predicted on the basis of only the octanol/water partition coefficient and molecular weight. The method may be applied to setting quality criteria for the aquatic environment and to ecotoxicological interpretation of (bio)monitoring data. Calculations were carried out for 102 narcotic compounds.
Reductive transformations of halogenated aromatic hydrocarbons in anaerobic water-sediment systems: Kinetics, mechanisms and products
Authors: Peijnenburg Willie J.G.M. , Hart Maarten J. 't , Den Hollander Henri A. , van de Meent Dik , Verboom Hans H. , Wolfe N. Lee 
Published: March 2010

AbstractThe degradation of several classes of halogenated aromatic hydrocarbons in methanogenic sediment-water systems was examined in laboratory studies. Several transformation processes were shown to occur, leading to formation of a variety of products. In the study a clear distinction could be made between transformation processes taking place immediately upon incubation of the compounds and processes taking place after a characteristic period of varying length. γ-Irradiation was used to quench biological reactions and thus assess the impact of those processes on the overall rates of degradation of the studied compounds. The kinetics of both the initial and the final processes were pseudo-first-order, with half-lives ranging from &lt;0.46 d to no detectable degradation for a number of multiply halogenated benzenes. Compounds were selected with the aim of obtaining a maximum variation in chemical reactivity and physical properties. The sediments were selected with the aim of assessing several environmental factors influencing the kinetics of reduction.
Using ratios of stable nitrogen isotopes to estimate bioaccumulation and flux of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in two food chains from the Northern Baltic
Authors: Broman Dag , Rolff Carl , Näf Carina , Zebühr Yngve , Fry Brian , Hobbie John 
Published: March 2010

Abstract
Presented in this study is a new method to quantitatively estimate in situ biomagnification of organic contaminants that uses ratios of naturally occurring stable isotopes of nitrogen to classify trophic levels of organisms from one littoral and one pelagic food chain in the northern Baltic proper. Results indicated a biomagnification of the three most toxic 2378-substituted polychlorinated dibenzo-p-dioxins and -dibenzofurans (PCDD/Fs), whereas the total concentration of 2378- substituted PCDD/Fs, and particularly octachlorodibenzo-p-dioxin and -dibenzofuran (OCDD/F), decreased with increasing trophic level in the food chains. A calculated flux estimate of PCDD/Fs in juvenile eider ducks was supported by results from the biomagnification study; that is, the most toxic 2378-substituted isomers tended to accumulate in the tissue of the eider duck. Out of the total PCDD/Fs consumed by the eider ducks, only 10% were recovered in the body and approximately 10% were recovered in feces, whereas 80% were not recovered, that is, were excreted or remained as unidentified metabolites. Of the most toxic 2378-substituted isomers, 57% were recovered in the tissue, 30% were recovered in the feces, and only 13% were not recovered (i.e., metabolized and/or excreted).
Effects of sediment organic carbon content on the elimination rates of neutral lipophilic compounds in the midge (Chironomus Riparius)
Authors: Lydy Michael J. , Baumann Paul C. , Oris James T. , Fisher Susan W. 
Published: March 2010

Abstract
The effects of varying sediment conditions on elimination rates for four neutral lipophilic compounds were investigated in midge larvae, Chironomus riparius. Four treatments were used: water only (no sediment present) (WO); midges screened from 3% organic carbon (OC) sediment (screened); water and 3% OC sediment (3% OC); and water and 15% OC sediment (15% OC). In general, elimination rates were larger in the 3 and 15% OC sediment systems compared to the WO and screened treatments. The largest elimination rates were found in the 15% OC treatments. The mechanism that accounts for increased elimination rates noted in the high-OC-content sediment systems is unknown; however, several possible mechanisms are discussed. A predictive relationship has been established between the elimination rate constant (Kd), the octanol/water partition coefficient (Kow), and sediment OC content. These results further emphasize the importance of sediment characteristics in determining the environmental fate of xenobiotics.
Glycolysis and krebs cycle metabolites in mosquitofish, Gambusia holbrooki, Girard 1859, exposed to mercuric chloride: Allozyme genotype effects
Authors: Newman Michael C. , Mulvey Margaret , Kramer Vincent J. , Ultsch Gordon R. 
Published: March 2010

Abstract
Concentrations of glycolysis and Krebs (citric acid) cycle metabolites were measured in the tail tissues of mosquitofish (Gambusia holbrooki, Girard 1859) in response to exposure to 0.86 mg/L Hg (as HgCl2) for 28 h. Substrate and product concentrations were compared between allozyme genotypes at two loci (glucosephosphate isomerase-2 and malate dehydrogenase-1) to determine whether allozyme genotypes in mosquitofish were differentially inhibited by mercury. Mercury treatment, regardless of allozyme genotype, caused decreased concentrations of glucose-6-phosphate (-27%) and lactate (-27%). Mercury treatment led to increased concentrations of malate (+33%) and oxaloacetate (+28%). Increased Krebs cycle activity could have been a response to greater energy needs associated with maintaining homeostasis under stressful conditions. There was no evidence of differential inhibition of allozymes at either locus. Fish of genotype Gpi-238/38 exhibited an overall increase in glycolytic activity in response to mercury treatment.
Laboratory spawning of topsmelt, Atherinops affinis, with notes on culture and growth of larvae
Authors: Middaugh D. P. , Hemmer M. J. , Anderson B. S. 
Published: March 2010

Abstract
Topsmelt (Atherinops affinis) were spawned repeatedly in the laboratory from May to July 1989. A periodic “temperature spike” from the holding temperature of approximately 18 up to approximately 20.5°C, introduced at 7- to 9-d intervals, resulted in maximum production of viable embryos on the fourth morning after the spike. Examination of embryonic stages and comparison to known developmental rates for Atherinops affinis embryos revealed that spawning was generally nocturnal, occurring between 1900 and 0500 h. Survival of embryonic and larval Atherinops affinis cultured at 21 ± 1°C and 20 ± 2‰ salinity was excellent (&gt;80%). A larval growth curve was developed for the first 24 d post-hatch.
Effects of fenvalerate on the early life stages of topsmelt (Atherinops Affinis)
Authors: Goodman Larry R. , Hemmer Michael J. , Middaugh Douglas P. , Moore James C. 
Published: March 2010

Abstract
Flow-through acute and early-life-stage (ELS) toxicity tests were conducted with topsmelt (Atherinops affinis), a Pacific coast saltwater fish, and fenvalerate, a synthetic pyrethroid insecticide. The 96-h LC50 for juvenile fish was 0.66 μg/L. In the 30-d ELS test with laboratory-spawned embryos, average measured fenvalerate concentrations were nondetectable (&gt;0.075 μg/L) in two control treatments, 0.14, 0.34, 0.82, 1.5, and 3.2 μg/L. Survival of embryos to hatching ranged from 94 to 100%, with no statistically significant differences among treatments. No fry survived exposure to fenvalerate concentrations ≥0.82 μg/L; overall survival in lower concentrations and control treatments ranged from 86 to 97%. There were no consistent concentration-dependent differences in weight between fish in the carrier-control treatment and fish exposed to fenvalerate. Mean wet weights of surviving fish ranged from 16.9 mg in 0.34 μg/L to 20.3 mg in 0.14 μg/L. The average bioconcentration factor for fish exposed to 0.14 and 0.34 μg fenvalerate per liter was 315.