bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of procedures for identifying pesticide toxicity in ambient waters: Carbofuran, diazinon, chlorpyrifos
Authors: Bailey Howard C. , Digiorgio Carol , Kroll Kevin , Hinton David E. , Miller Jeffrey L. , Starrett Gwen 
Published: March 2010

Abstract
The responses of carbofuran, diazinon, and chlorpyrifos to standard acute toxicity identification evaluation (TIE) procedures were characterized. The test species was Ceriodaphnia dubia. The TIE procedures included solid-phase extraction, recovery in methanol eluates, hydrolysis under acid and base conditions, and retention in specific methanol/water fractions. In addition, the effect of the metabolic inhibitor, piperonyl butoxide, on the toxicity of each of the pesticides was determined. Diazinon degraded quickly under acid conditions, whereas carbofuran degraded under base conditions. In both cases, concentrations were reduced to nontoxic levels within 6 h. Conversely, acidic or basic conditions were not effective in reducing the concentration of chlorpyrifos over the same time period. Solid-phase extraction removed at least 95% of diazinon and carbofuran from solution, but was less effective with chlorpyrifos. All three pesticides eluted separately in characteristic methanol/water fractions. Piperonyl butoxide ameliorated the toxicity of diazinon and chlorpyrifos, but not carbofuran. Up to 1.5% methanol did not interfere with the protective action of piperonyl butoxide. Case studies in which these techniques were applied to ambient water samples are also described.
Persistence of white phosphorus (P4) particles in salt marsh sediments
Authors: Walsh Marianne E. , Collins Charles M. , Racine Charles H. 
Published: March 2010

Abstract
Remediation of sediments at Eagle River Flats, Alaska, a salt marsh contaminated with solid particles of white phosphorus (P4), may require severe alterations of the wetland by dredging, draining, or covering. However, some sediments may undergo decontamination naturally in areas that are seasonally subaerially exposed. The persistence of millimeter-size P4 particles was studied in laboratory and field experiments. White phosphorus particles were found to be persistent in saturated sediments. In unsaturated sediments, loss was rapid (within 24 h) at 20°C, and was retarded by low temperatures.
Uptake of cesium-134 by the earthworm species Eisenia foetida and Lumbricus rubellus
Authors: Janssen Martien P. M. , Glastra Peter , Lembrechts Johan F. M. M. 
Published: March 2010

Abstract
The uptake processes of 134Cs in two earthworm species were investigated as well as the effect of temperature on these processes. The results show that equilibrium concentrations in the two species differ by 1.5-to fivefold. Equilibrium concentrations range from 367 to 963 Bq g−1 in Lumbricus rubellus and from 920 to 1,893 Bq g−1 in Eisenia foetida; biological half-lives range from 56 to 119 h and 52 to 64 h, respectively. Assimilation was two to four times higher in E. foetida and elimination rate one to two times higher in E. foetida than in L. rubellus. Further, the results show that temperature may affect the 134Cs concentration in these earthworms by a factor of 1.4 to 2.1 between 10 and 20°C, depending on the species. The maximum difference found within one species was a factor of 2.6. Our results show no clear effect of temperature on the assimilation, but a small negative effect on elimination, resulting in an increasing biological half-life and concentration factor with higher temperatures.
Bioaccumulation, metabolism, and biochemical effects of the organophosphorus pesticide fenitrothion inProcambarus clarkii
Authors: Escartín Estefania , Porte Cinta 
Published: March 2010

AbstractFenitrothion (O,O-dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate) is readily taken up from the water by the crayfish Procambarus clarkii. The bioconcentration factor, however, is lower than expected on the basis of its octanol/water partition coefficient. The ability of P. clarkii to metabolize fenitrothion was evaluated in vitro by using 12,000-g supernatant or microsomal fractions isolated from hepatopancreas and the results pointed out the existence of both oxidative and glutathione-mediated metabolism. Several biomarkers of exposure viz., the microsomal mixed-function oxygenase system, a phase II enzyme [glutathione S-transferase], and acetylcholinesterase inhibition, were studied in organisms exposed to 20 μg/L of fenitrothion for 48 h. Cytochrome P450 content, NADPH cytochrome c(P450) reductase, and 7-ethoxyresorufin O-deethylase activity showed significant induction the second day of treatment, whereas glutathione S-transferase activity appeared to be unaffected. Acetylcholinesterase activity in the neuromuscular tissue of P. clarkii was a good indicator of exposure to this compound.
Long-term effects of copper and ph on the nematode community in an agroecosystem
Authors: Korthals Gerard W. , Bongers Tom , Kammenga Jan E. , Alexiev Alexey D. , Lexmond Theo M. 
Published: March 2010

Abstract
Four copper (0, 250, 500, and 750 kg Cu · haa−1) and pH (4.0, 4.7, 5.4, and 6.1 in 1 M KCl) treatments were applied to an arable agroecosystem. Effects on the nematode community were assessed after 10 years of exposure under field conditions. Both copper and pH had major influences on nematodes. The effect of copper was generally enhanced with decreasing soil pH. The lowest copper application rate which had a significant negative effect on the total number of nematodes was 250 kg. ha−1 at pH 4.0, which is equivalent to a copper concentration of 0.32 mg.L−1 in 0.01 M calcium chloride (Cu-CaCl2). Species composition and the abundance of trophic groups were more sensitive than the total number of nematodes. Combinations of high copper and low pH significantly reduced the number of bacterial-feeding nematodes, whereas the number of hyphal-feeding nematodes increased. Omnivorous and predacious nematodes showed the most sensitive response, becoming extinct when Cu-CaCl2 was 0.8 to 1.4 mg.L−1. Plant-feeding nematodes showed the largest differences in abundance and appeared to reflect the effects of copper and pH on primary production. The results suggest that the nematode community was also affected indirectly by copper and pH via other components of the soil food web. It is concluded that nematodes offer excellent perspectives to assess effects of pollutants at the community level.
Physicochemical changes of aluminium in mixing zones: Mortality and physiological disturbances in brown trout (Salmo trutta L.)
Authors: Witters Hilda E. , VanPuymbroeck Sylvain , Stouthart Alexander J. H. X. , Bonga Sjoerd E. Wendelaar 
Published: March 2010

Abstract
A standardized laboratory setup, smulating field mixing zones that originate at the confluence of limed rivers with acidic, aluminium-rich, tributaries, has been developed. Detailed analyses of the chemical speciation of aluminium (Al) in relation to the biological response of brown trout were performed to identify the mechanism of unexpected high fish mortality in the above-mentioned mixing zones with pH levels above 6.0. Brown trout experienced an acute cumulative mortality (98% in 48 h) immediately afterneutral and acidic, Al-rich, water had mixed. Mortality was only 60% within 48 h of exposure to the acid water with Al (pH 4.6 +6.8 μmol Al/L), although the Al concentration in the mixing zone was less (2.8 μmol Al/L) at a nonharmful pH level (pH 6.4). Chemical speciation and ultrafiltration studies demonstrated that the transformation of low-molecular weight Al (&lt;10 kD) into high-molecular weight Al (&gt; 10 kD), defined as Al polymerization, could better be related to the toxic response offish, than the total Al concentration. The aging of polymerized Al forms (for 480 s) resulted in reduced fish mortality and less pronounced physiological stress. Brown trout in the initial mixing zone showed significantly increased plasma glucose and cortisol levels. Light and electron microscopy studies demonstrated serious damage to the skin: increased mucous secretion, a high ratio of acid to neutral glycoprotein-containing mucous cells, increased apoptosis, and infiltration of leucocytes and macrophages between the epithelial cells. Ionoregulatory parameters, which showed minor changes in fish in the initial mixing zone, did not allow explanation of acute fish mortality. Data on the ventilation frequency and the blood hematocrit, which both increased, gave support for the hypothesis that acute fish mortality in mixing zones could be caused by respiratory dysfunction.
Effects of a nonionic surfactant (c14–15 AE-7) on fish survival, growth and reproduction in the laboratory and in outdoor stream mesocosms
Authors: Kline Edward R. , Figueroa Rocio A. , Rodgers John H. , Dorn Philip B. 
Published: March 2010

Abstract
The effects of a nonionic surfactant (C14–15 AE-7) on survival and growth of juvenile bluegill sunfish and on survival and reproduction of fathead minnows were investigated in the laboratory and in outdoor stream mesocosms. In the laboratory, where the fish were exposed for 10 d, the 96-h LC50 values for bluegill sunfish and fathead minnows were 650 and 770 μg/L, respectively. The no-observed-effect concentration (NOEC) for survival and swimming performance of bluegill sunfish and for survival of fathead minnows was 160 μg/L. The lowest-observed-effect concentration (LOEC) for these toxic responses was 460 μg/L. In the stream mesocosms, where the fish were exposed for 30 d, the NOEC for bluegill sunfish survival and growth was &gt;330 μg/L. The LOEC for fathead minnow survival was 330 μg/L, and the NOEC was 280 μg/L. Decreased egg laying by fathead minnows was noted in the streams at concentrations of 330 μg/L or greater. Close correspondence between the results of laboratory tests and those obtained under field conditions in the mesocosms indicates that for this surfactant, it may not be necessary to apply “safety factors” to extrapolate results from the laboratory to the field.
Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower laguna madre, texas
Authors: Mora Miguel A. 
Published: March 2010

Abstract
Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p &lt; 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.
Modeling the nucleophilic reactivity of small organochlorine electrophiles: A mechanistically based quantitative structure-activity relationship
Authors: Verhaar Henk J. M. , Seinen Willem , Hermens Joop L. M. , Rorije Emiel , Borkent Hens 
Published: March 2010

Abstract
Environmental pollutants can be divided into four broad categories, narcosis-type chemicals, less inert (“polar narcosis”) chemicals, reactive chemicals, and specifically acting chemicals. For narcosis-type, or baseline, chemicals and for less inert chemicals, adequate quantitative structure-activity relationships (QSARs) are available for estimation of toxicity to aquatic species. This is not the case for reactive chemicals and specifically acting chemicals. A possible approach to develop aquatic toxicity QSARs for reactive chemicals based on simple considerations regarding their reactivity is given. It is shown that quantum chemical calculations on reaction transition states can be used to quantitatively predict the reactivity of sets of reactive chemicals. These predictions can then be used to develop aquatic toxicity QSARs.
Chronic effects of nonpolar narcotics on a model microbial community
Authors: Jaworska Joanna S. , Hallam Thomas B. , Schultz Terry W. 
Published: March 2010

Abstract
The dynamics of a model of a microbial batch culture community consisting of Tetrahymena pyriformis and Escherichia coli populations are explored when the community is stressed by chemicals with a nonpolar narcosis mode of action. The framework for the community consists of two individual-based population models, individual models of the organisms T. pyriformis and E. coli, and exposure and effect modules for each species. The exposure module is based on passive diffusion and describes both environmental and resource routes of exposure. The effect module utilizes quantitative structure–activity relationships to determine resource uptake reduction, the effect chosen as the primary consequence of exposure to the chemical. The range of possible effects on the model ciliate–bacterial community includes results that do not arise from population studies; for example, chemically depressed growth rates of individuals can be stimulatory for a population in a community setting. Community structure and feedback mechanisms are demonstrated to be fundamental for effects determination in that structure evolves as a function of exposure concentration. In a closed system, the presence of nonviable organic material modifies bioavailability of the toxicant and allows for community persistence above concentration levels that cause mortality in a continuous culture. An indicator of stress, the community extinction threshold, is developed as a function of chemical diffusivity and hydrophobicity.
DNA damage and radiocesium in channel catfish from chernobyl
Authors: Sugg Derrick W. , Brooks Janet A. , Jagoe Charles H. , Smith Michael H. , Chesser Ronald K. , Bickham John W. , Lomakin Michael D. , Dallas Cham E. , Baker Robert J. 
Published: March 2010

AbstractThe explosion of the Chernobyl Nuclear Power Plant resulted in some of the most radioactively contaminated habitats on earth. Despite evacuation of all human inhabitants from the most contaminated areas, animals and plants continue to thrive in these areas. This study examines the levels of contamination and genetic damage associated with radiocesium in catfish (Ictalurus punctatus) from the cooling pond and a control site. In general, catfish from the cooling pond exhibit greater genetic damage, and the amount of damage is related to the concentration of radiocesium in individual fish. Genetic damage is primarily in the form of DNA strand breaks, with few micronuclei being observed in contaminated fish. The possible roles that acclimation and adaption play in the response to high levels of radiation exposure are discussed.
Hydrolysis of carbon tetrachloride
Authors: Jeffers Peter M. , Brenner Christine , Lee Wolfe N. 
Published: March 2010

Abstract
New experimental data on the hydrolysis of dilute solutions of carbon tetrachloride (CCl4) indicate clearly that the reaction is first–order in CCl4, a conclusion contrary to the classic work of Fells and Moelwyn-Hughes. These historical data have been reanalyzed and shown to be consistent with first-order kinetics. A new determination of the Arrhenius parameters confirm an environmental half-life of 40 years for CCl4.
A Test of sediment effects concentrations: DDT and PCB in the southern california bight
Authors: Chapman Peter M. 
Published: March 2010

Abstract
Independent efforts to determine concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethanes (DDTs) along the Southern California Bight which result in adverse biological effects resulted in similar values. A correlative approach using historic data calculated the following likely sediment effects concentrations: total DDTs, 7.12 mg/dry kg (199 mg/kg organic carbon [OC]); and total PCBs, 0.592 mg/dry kg (30.4 mg/kg OC). Testing of field-collected sediments yielded the following no-observed-effect concentrations based on full life-cycle testing: total DDTs, 8.51 mg/dry kg (269 mg/kg OC); and total PCBs, 1.07 mg/dry kg (36.6 mg/kg OC).
Characterization of mussel beds with residual oil and the risk to foraging wildlife 4 years after the Exxon valdez oil spill
Authors: Boehm Paul D. , Mankiewicz Paul J. , Reilly James E. O. , Hartung Rolf , Neff Jerry M. , Page David S. , Gilfillan Edward S. , Parker Keith R. 
Published: March 2010

Abstract
The grounding of the Exxon Valdez on March 24, 1989, released about 41 million L of crude oil into the waters of Prince William Sound, Alaska, USA, and oiled about 16% of the Prince William Sound shoreline to various degrees. Although winter storms, cleanups, and natural biodegradation have removed the majority of the oil on the shorelines, some residual oil still remains trapped in sediments immediately below mussel beds. This oil was protected from wave action by the dense covering of mussels. Field surveys found that mussels in such beds constituted less than 3% of the mussels available for foraging in two areas that had been extensively oiled in 1989. Levels of polycyclic aromatic hydrocarbons (PAHs) in these mussels were also measured. Mean PAH concentrations in mussel tissues ranged between 20 and 4,000 ng/g dry weight and in sediments between 20 and 26,000 ng/g dry weight. Assuming that the species considered most at risk (i.e., harlequin ducks, black oystercatchers, and sea otters) consumed the mussel proportion of their diets exclusively from such beds (at either the median or 95th percentile of mussel tissue PAH concentration), the estimated PAH dosage they would receive was one to three orders of magnitude below doses known to cause sublethal effects in surrogate species. Considering the low frequency of mussel beds with residual oil, the patchy distribution of remaining weathered oil residues, and the relatively low PAH concentrations in the mussels, the risk of quantifiable injury at the level of an individual bird or otter, or at the population level, is minimal. Furthermore, based on a review of the mussel PAH data in Prince William Sound, the risk to wildlife has been minimal since 1990, 1 year after the spill.
Acute and subchronic toxicity of methylene blue to larval fathead minnows (Pimephales promelas): Implications for aquatic toxicity testing
Authors: Rifici Louis M. , Cherry Donald S. , Farris Jerry L. , Cairns John 
Published: March 2010

Abstract
The acute and 7-d subchronic toxicity of methylene blue were determined for fathead minnow larvae using U.S. Environmental Protection Agency methods. The 96-h lethal concentration (LC50) was 45 and 15 mg/L at 20 and 25°C, respectively. The 7-d chronic value for survival under laboratory light and low light was the same (2.1 mg/L). However, under laboratory light, larval growth was impaired at lower concentrations (chronic value = 0.6 mg/L) than under low light (chronic value = 2.1 mg/L). To assess prior methylene blue treatment on larval sensitivity, embryos, larvae &lt;24 h old, and embryos followed by larvae were treated with 3 mg/L methylene blue. Cadmium LC50 values were similar between methylene blue-treated and untreated control groups. When larvae treated with methylene blue as embryos were subchronically exposed to an effluent, survival was similar to that of the untreated group. However, dry weight of the treated larvae was significantly lower. Differences in dry weight between treated and untreated groups were reduced as the age of the larvae at test initiation increased. Treatment of incubating embryos using 3 mg/L methylene blue does not appear to affect larvae sensitivity to cadmium but may affect the growth of larvae used in subchronic testing.
Interlaboratory study of precision:Hyalella aztecaandChironomus tentansfreshwater sediment toxicity assays
Authors: Burton G. Allen , Norberg-King Teresa J. , Benoit Duane A. , Ankley Gerald T. , Winger Parley V. , Kubitz Jody , Lazorchak James M. , Smith Mark E. , Call Daniel J. , Ingersoll Christopher G. , Greer Eugene , Dwyer F. James , Day Kristin E. , Kennedy Paul , Stinson Margaret 
Published: March 2010

AbstractStandard 10-d whole-sediment toxicity test methods have recently been developed by the U.S. Environmental Protection Agency (EPA) for the amphipod Hyalella azteca and the midge Chironomus tentans. An interlaboratory evaluation of method precision was performed using a group of seven to 10 laboratories, representing government, academia, and environmental consulting firms. The test methods followed the EPA protocols for 4-d water-only reference toxicant (KCl) testing (static exposure) and for 10-d whole-sediment testing. Test sediments included control sediment, two copper-containing sediments, and a sediment contaminated primarily with polycyclic aromatic hydrocarbons. Reference toxicant tests resulted in H. azteca and C. tentans median lethal concentration (LC50) values with coefficents of variation (CVs) of 15.8 and 19.6%, respectively. Whole sediments which were moderately contaminated provided the best estimates of precision using CVs. Hyalella azteca and C. tentans tests in moderately contaminated sediments exhibited LC50 CVs of 38.9 and 13.5%, respectively. The CV for C. tentans growth was 31.9%. Only 3% (1 of 28) of samples exceeded acceptable interlaboratory precision limits for the H. azteca survival tests. No samples exceeded the intralaboratory precision limit for H. azteca or C. tentans survival tests. However, intralaboratory variability limits for C. tentans growth were exceeded by 80 and 100% of the laboratories for a moderately toxic and control sample, respectively. Interlaboratory variability limits for C. tentans survival were not exceeded by any laboratory. The results showed these test methods to have relatively low variance and acceptable levels of precision in interlaboratory comparisons.
Nontarget effects of a test application of diflubenzuron to the forest canopy on stream macroinvertebrates
Authors: Hurd Martin K. , Perry Sue A. , Perry William B. 
Published: March 2010

Abstract
Forest application of diflubenzuron (DFB) is commonly used in mid-Atlantic states for control of gypsy moths in hardwood forests. To assess effects of the pesticide on nontarget organisms, DFB (Dimilin) was applied by helicopter on May 16, 1992, to two watersheds in the Fernow Experimental Forest near Parsons, West Virginia. To determine if aquatic macroinvertebrates were affected by the aerial spray, we monitored streams in two reference and two treatment watersheds before and after treatment with DFB using a multilevel artificial substrate sampler. The before-after-control-impact-pairs (BACIP) analysis was used to test for differences in aquatic macroinvertebrate densities between treated and reference watersheds. Densities of some taxa in DFB-treated watersheds either showed population depressions or did not increase in density after drought conditions as compared with those taxa in streams in reference watersheds, whereas other taxa increased in treated watersheds. Taxa that had reduced mean densities in treatment watersheds (α = 0.05) included the stoneflies, Leuctra sp. and Isoperla sp., the mayfly, Paraleptophlebia sp., and the crane fly, Hexatoma sp. Shredders, the dominant functional feeding group, also had reduced mean densities in treatment watersheds. Densities of Oligochaeta and Turbellaria increased in streams in treated watersheds.