bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting and measuring drift of Bacillus thuringiensis sprays
Authors: Barry John W. , Skyler Patricia J. , Teske Milton E. , Rafferty James A. , Grim Bruce S. 
Published: March 2010

Abstract
Drift of the pesticide Bacillus thuringiensis Berliner var. kurstaki (Bt) was measured downwind from a gypsy moth (Lymantria dispar L.) treatment block in mountain terrain. The study was conducted in conjunction with a project to eradicate the moth along the Wasatch mountain range of Utah. Objectives of the study were to quantitate drift, to evaluate drift sampling methods, and to compare FSCBG (Forest Service Cramer-Barry-Grim) computer model predictions to field measurements of Bt based on colony-forming units. The treatment block was sprayed by helicopter three times, within a 12-d period during June 1991, which provided a study of three replicates. During each spray, downslope drainage winds carried the spray over an array of samplers that extended 3,150 m downwind. The FSCBG dispersion model, exercised after the treatments, used meteorological inputs measured during the treatments to predict spray deposition and airborne dosage of Bt. Results of the study demonstrated a correlation among dosage, deposition and total flux samplers; a potential of Bt drift of at least 3,150 m; and FSCBG model predictions that generally followed the field recovery data.
Distribution of PCB congeners in seven lake systems: Interactions between sediment and food-web transport
Authors: Macdonald Colin R. , Metcalfe Chris D. , Balch Gordon C. , Metcalfe Tracy L. 
Published: March 2010

Abstract
A study was conducted to examine the role of two processes, partitioning of PCBs between sediment and biota and food-web transport, in determining the concentration of PCB congeners in the biota of seven lakes. Biota PCB concentration (lipid)-to-sediment PCB concentration (organic carbon), or BSF, ratios were calculated as markers of the partitioning of PCBs between biota and sediment, and biota PCB concentration (lipid)-to-zooplankton PCB concentration (lipid), or BAF, ratios were calculated as markers of the transport of PCBs through food webs. The lakes ranged from a shallow, well-mixed lake with a historic input of Aroclor technical mixtures to deeper, oligotrophic systems in which atmospheric deposition was the only known source. BSF ratios ranged from approximately one in cyprinids and zooplankton in all lakes to 30 in yellow perch in one lake. A significant correlation between lake maximum depth and the combined BSF ratios for all biota indicated that PCBs were generally more available for accumulation in the shallower lakes, regardless of the PCB source. Principal component analysis (PCA) showed that the biota in the shallower lakes had higher ratios of higher chlorinated congeners, suggesting that predictions of equal concentrations of hydrophobic contaminants on a lipid basis in sediment and lower trophic levels may significantly underestimate the accumulation of very hydrophobic compounds in the organisms of some lake systems. BAF ratios ranged from approximately one in the lower trophic levels to approximately 10 in lake trout. A significant relationship between the BAF ratio and lake maximum depth for combined data for all biota, and particularly for smallmouth bass (Micropterus dolomieui Lacé-pède), probably indicated the increasing role of food-web transport of PCBs in deeper lakes. PC analysis of BAF ratios for individual congeners characterized lake trout (Salvelinus namaycush Wal-baum) and yellow perch (Perca flavescens) on the basis of higher ratios for the majority of congeners but also split the two species on the basis of higher ratios of lower chlorinated congeners in perch and highly chlorinated congeners in lake trout. The separation of the two species collected from the same lakes was attributed to their position in the food web.
The oxidative dechlorination reaction of 2,4,6-trichlorophenol in dilute aqueous suspensions of manganese oxides
Authors: Ukrainczyk Ljerka , McBride Murray B. 
Published: March 2010

AbstractOxidation of 2,4,6-trichlorophenol (TCP) by layered manganese oxides (Na and Co-buserite) in dilute acidified aqueous suspension gives 2,6-dichloro-p-benzoquinone as a major product. This compound is likely to further polymerize and become incorporated into humuslike materials. The oxidation rate was higher at lower pH and higher on Na-buserite compared to Co-buserite. TCP reacted at a faster rate than unsubstituted phenol at pH 3 and 5.5, which is explained by (a) the lower half-wave potential of TCP compared to phenol; (b) a stronger bond dipole associated with the electronegative halogen, favoring an addition step in nucleophilic substitution; and (c) easier deprona-tion of TCP at the manganese oxide-water interface due to its lower pKa. IR spectroscopy shows that TCP adsorbs in deprotonated form on the surface of manganese oxide, and it cannot be washed from the surface by water. Nucleophilic attack by addition-elimination is suggested as a mechanism of TCP dechlorination and oxidation.
Oxidation and dechlorination of chlorophenols in dilute aqueous suspensions of manganese oxides: Reaction products
Authors: Ukrainczyk Ljerka , McBride Murray B. 
Published: March 2010

AbstractSome monomeric and dimeric oxidation products of para- and/or ortho-chlorinated phenols in dilute (1 mmol/L phenol), acidified, aqueous suspensions of manganese oxide (Na-buserite) were identified by MS, Fourier-transform IR spectroscopy and UV/visible spectroscopy. The para-chlorinated phenols (4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 4-chloro-2-methylphenol) gave corresponding p-benzoquinones (benzoquinone, 2-chlorobenzoquinone, 2,6-dichlorobenzoquinone, 2-methylbenzoquinone) as the detectable water-soluble oxidation products. Dimeric products were present in the extracts obtained by washing the oxide with methylene chloride. Michael addition of phenolate to quinone seems to be the predominant mode of coupling. Chlorinated phenols without chlorine in the para-position (2-chlorophenol, 2,6-dichlorophenol) were more difficult to oxidize and afforded diphenoquinones as the only detectable water-soluble products. For all studied phenols, with the exception of 2,4,6-trichlorophenol, the amount of water-soluble products accounts only for a small fraction of oxidized phenol. The quinone and diphenoquinone products readily couple with phenols into humuslike materials.
The effect of cosolutes on the aqueous solubilities and octanol/water partition coefficients of selected polychlorinated biphenyl congeners
Authors: Li An , Doucette William J. 
Published: March 2010

Abstract
Aqueous solubilities (S) and 1-octanol/water partition coefficients (Kow) of four PCBs—4-chlorobiphenyl, 2,4,6-trichlorobiphenyl, 2,3,4,5-tetrachlorobiphenyl, and 2,2′,4,4′,6,6′-hexachlo-robiphenyl—were determined both individually and in pairs, using a generator-column technique, to investigate the effect of cosolutes on S and Kow, No statistical differences between S and Kow measured individually and in pairs were observed for the four PCBs in 20 out of 24 cases. In the other four cases S or Kow measured in the presence of a cosolute was only slightly different from that observed individually.
Chemical, physiological and morphological studies of feral baltic salmon (Salmo salar) suffering from abnormal fry mortality
Authors: Norrgren L. , Andersson T. , Bergqvist P.-A. , Björklund I. 
Published: March 2010

Abstract
In 1974, abnormally high mortality was recorded among yolk-sac fry of Baltic salmon (Salmo salar) originating from feral females manually stripped and fertilized with milt from feral males. The cause of this mortality, designated M74, is unknown. Our hypothesis is that xenobiotic compounds responsible for reproduction failure in higher vertebrates in the Baltic Sea also interfere with reproduction in Baltic salmon. The significance of M74 should not be underestimated, because the syndrome has caused up to 75% yearly mortality of developing Baltic salmon yolk-sac larvae in a fish hatchery dedicated to production of smolt during the last two decades. We cannot exclude the possibility that only a relatively low number of naturally spawned eggs develop normally because of M74. No individual pollutant has been shown to be responsible for the development of M74 syndrome. However, a higher total body burden of organochlorine substances may be responsible for the M74 syndrome. The presence of induced hepatic cytochrome P450 enzymes in both yolk-sac fry suffering from M74 and adult feral females producing offspring affected by M74 supports this hypothesis. In addition, the P450 enzyme activity in offspring from feral fish is higher than the activity in yolk-sac fry from hatchery-raised fish, suggesting that feral Baltic salmon are influenced by organic xenobiotics.
Induction of mfo enzymes and production of bile metabolites in rainbow trout (Oncorhynchus mykiss) exposed to waste crankcase oil
Authors: Upshall C. , Payne J.F. , Hellou J. 
Published: March 2010

Abstract
It is difficult to assess the toxicological significance of complex mixtures of contaminants in the environment because of paucity of dose-response studies. Rainbow trout (Oncorhynchus mykiss) were exposed per os to waste crankcase oil and analyzed for hydrocarbon classes, 26 polycyclic aromatic compounds (PACs) and 66 elements. MFO enzyme activity, measured as 7-ethoxyresorufin O-deethylase (EROD) was induced in liver, kidney, and heart. The threshold level for induction in liver was approximately 3 mg of PACs (sum of 26 PACs) per kilogram fish. A dose-response relationship was obtained for liver and kidney but not for the heart. In a time-response study, liver, kidney, and heart MFO activity increased (14-, 5-, and 3-fold, respectively), reaching a maximum between days 1 and 4, then decreased to basal levels by day 12. Analysis of bile metabolites, as gluc-uronide and sulfate conjugates, showed a pattern similar to that displayed by MFO induction, possibly with a slight delay. This study establishes time- and dose-response relationships for MFO enzyme induction and appearance of bile metabolites in fish exposed to an environmentally important source of PACs.
Survival and pesticide exposure of northern bobwhites (Colinus virginianus) and eastern cottontails (sylvilagus floridanus) on agricultural fields treated with counter® 15G
Authors: Tank Susan L. , Brewer Larry W. , Hooper Michael J. , Cobb George P. , Kendall Ronald J. 
Published: March 2010

Abstract
During 1988 and 1989 northern bobwhites (Colinus virginianus) and eastern cottontails (Sylvilagus flondanus) were radiotagged and their daily survival monitored on six study sites treated with the organophosphorus insecticide-nematicide Counter®15G (terbufos), at the rate of 1.45 kg a.i. per hectare, and on three reference sites. Nonlethal blood samples were collected at the time of capture and during subsequent recaptures to determine exposure to terbufos through blood ChE analysis. Survival rates of radiotagged eastern cottontails and blood plasma ChE activities were not different between treated and reference sites in either year. Gastrointestinal (GI) tracts of two cottontail carcasses found in 1988 contained traces of terbufos in concentrations &lt;0.046 ppm. No terbufos was detected in GI tracts in 1989. There were no differences in survival rates of radiotagged northern bobwhites among treatments. Mean blood plasma ChE activities of northern bobwhites were significantly lower (P &lt; 0.05) on treated sites than on reference sites both years, including sublethal exposure to the test chemical. No GI tract residues were detected in bobwhites in 1988, and GI tract residues were detected in trace amounts (&lt;0.046 ppm) in only one bobwhite carcass in 1989.
Validation of some extrapolation methods used for effect assessment
Authors: Emans H.J.B. , Plassche E.J.V.D. , Canton J.H. , Okkerman P.C. , Sparenburg P.M. 
Published: March 2010

Abstract
For effect assessment several extrapolation methods can be used to derive the concentration of toxic chemicals above which adverse effects on aquatic ecosystems may occur. These methods are based on single-species toxicity data. At present, however, it is uncertain whether the values calculated with these extrapolation methods really represent accurate estimations of concentrations harmless to ecosystems. Therefore a validation of extrapolation methods was carried out by comparing NOECs derived from multiple-species (semi-) field experiments with extrapolated values. In this study validation was restricted to the methods of Aldenberg and Slob and Wagner and Løkke and a modification of the method of the U.S. Environmental Protection Agency. Multiple-species experiments for organic compounds and metals in aquatic ecosystems were studied. For only 29 compounds, 19 organic compounds, and 10 metals, one or more multiple-species NOECs could be derived. For 11 of these compounds an insufficient amount of single-species toxicity data was available to apply the methods of Aldenberg and Slob and Wagner and Løkke. With reservations, due to this paucity of data, it is concluded that single-species toxicity data can be used to derive “safe” values for the aquatic ecosystem. Furthermore, extrapolation methods seem to be a good basis for determining these values. Based on the results of this study, the best correlation between multiple-species NOECs and extrapolated values can be obtained with the methods of Aldenberg and Slob and Wagner and Løkke, both with a 95% protection level and a 50% confidence level.
Salt-marsh processes: A Review
Authors: Vernberg F. John 
Published: March 2010

Abstract
Salt marshes are found between the high tide and the near-shore sublittoral zones along the coasts and up estuaries of continents, primarily in the temperate zone. They flourish in regions where much silt is carried to the coastal regions by rivers or where geological processes favor erosion and suspension of silt. Salt marshes have multiple ecological and economic values. They have a high rate of primary productivity; provide habitats for many marine species (including commercially important organisms); assist in flood and erosion control; lessen the effects of stormwater surges; and improve water quality by filtering pollutants, excess nutrients, and disease-causing microorganisms. In addition, this habitat is used for recreational and educational purposes by millions of people who spend millions of dollars. Although the myriad functions and uses of this habitat attest to its tremendous importance, legal protection of salt marshes varies significantly throughout the world. Salt-marsh processes are governed by the interactions between “natural” physical, chemical, geological, and biological factors. Of importance to ecotoxicologists and other scientists is understanding the intimate interaction between these various abiotic and biotic factors. This paper reviews the functional processes of salt marshes and discusses recent research advances under the following major headings: (a) physical, geological, and chemical factors; (b) biotic factors (including productivity of vascular plants, phytoplankton, epibenthic algae, and attached macrophytes; secondary production of primary and secondary consumers; and decomposition; (c) material cycling, biogeo-chemical cycling, and nutrients; (d) long-term changes; and (e) interaction with adjacent ecosystems.
Ecotoxicology and wetland ecosystems: Current understanding and future needs
Authors: Catallo W. James 
Published: March 2010

Abstract
The term wetlands refers to a mosaic of important ecosystems that typically form transition zones between uplands and aquatic environments. These areas provide support functions for natural and living resources and mediate biogeochemical transformations of global significance. It is becoming clear that the introduction of toxic and other contaminants to large wetland areas has contributed to a series of undesirable trends in habitat quality; availability of valuable fish and wildlife; and quality of associated resources, including surface and ground waters. The purpose of this review is to indicate the importance of wetlands to regional and global ecology and discusses research on the effects of contaminants in wetland ecosystems. Areas of needed future research also are suggested.
Modeling mobility and effects of contaminants in wetlands
Authors: Dixon Kenneth R. , Florian James D. 
Published: March 2010

Abstract
Early efforts at modeling wetland ecosystems were aimed primarily at reflecting biomass or nutrient dynamics. A number of models have been developed for different wetland types, including coastal salt marshes, mangrove wetlands, freshwater marshes, swamps, and riparian wetlands. The early ecosystem models were mostly simple compartment models with linear, constant-coefficient differential equations used to simulate biomass or nutrient dynamics. Practically no contaminant flux was incorporated into these models. With few exceptions, the ecosystems were considered spatially homogeneous. At the same time that the ecosystem models were being developed, considerable effort was given to modeling various wetland processes, such as circulation and sediment transport. Other process-level modeling included plant and animal uptake and elimination of both organic chemicals and heavy metals. The level of detail in these process models, however, has not been applied to most ecosystem models. There has been a recent trend, however, to increase the complexity of ecosystem-level models and to incorporate spatial dynamics. These developments should greatly enhance the ability to simulate contaminant transport and effects in wetlands.
Detection of contaminated samples using a two-way compositing scheme
Authors: Skalski John R. , Word Jack Q. 
Published: March 2010

Abstract
Compositing of sediment or water samples provides an opportunity to screen numerous samples economically if contamination is a relatively rare occurrence. However, standard compositing procedures simply identify that contamination exists among one or more constituent samples of the composite. Using a two-way compositing strategy, detected contamination in composited samples can be attributed directly to constituent samples without further analyses. Procedure is illustrated using benthic sediment samples contaminated with crude oil following an oil spill. The proposed compositing scheme has a relative efficiency of n/2 compared to the analysis of individual samples when n2 is the number of samples screened (e.g., n2 = 16 samples, relative efficiency is 4/2 = 2).
Biological and chemical mineralization of pyridine
Authors: Ronen Zeev , Horvath-Gordon Maria , Bollag Jean-Marc 
Published: March 2010

Abstract
A comparison was made between biological and chemical mineralization of pyridine, an N-heterocyclic pollutant, in a liquid culture and a slurry of ground water and subsurface sediment. A bacterial culture of an Alcaligenes sp. that degrades pyridine was found to be more effective at oxidizing [2,6-14C]pyridine to 14CO2 than Fenton's reagent. Alcaligenes sp. converted 73.1% of the 14C-labeled pyridine to 14CO2, whereas the Fenton reagent converted 65.6% of the compound. In the case of bacteria, the remaining chemical was incorporated primarily into biomass (9.2%), whereas the remaining pyridine was converted to unidentified products (16.3%) by the Fenton reagent. However, based on chromatographic analysis, these compounds were not mono-hydroxylated pyridines. Mineralization of pyridine by Fenton's reagent was affected by the concentration of H2O2 and by the concentration and oxidation state of available iron. Maximal mineralization occurred at a concentration of more than 0.15% H2O2 (44 mM), 1 mM Fe3+, or 2 mM Fe2+. Furthermore, the rates of both microbial and chemical mineralization were influenced by the initial pyridine concentration. Maximum specific rates of mineralization were 6.5 μg/h/mg biomass for the bacteria and 2.7 μg/h/mg Fe2+ for the Fenton reagent. The feasibility of using Fenton's reagent for treating ground water and subsurface sediments polluted with pyridine was found to be limited, because only 24.5% of the pyridine was converted to CO2. In contrast, when cultures of the Alcaligenes sp. were used to treat ground water, as much as 54.4% of the labeled compound was mineralized to 14CO2.
Photoeffects of textile dye wastewaters: Sensitization of singlet oxygen formation, oxidation of phenols and toxicity to bacteria
Authors: Tratnyek Paul G. , Elovitz Michael S. , Colverson Peter 
Published: March 2010

Abstract
An effluent sample from a municipal wastewater treatment plant that receives a heavy loading from two textile dyeing facilities was tested for a variety of photoeffects. Solar irradiation of solutions containing the effluent produced evidence for sensitized formation of transient oxidants, primarily singlet oxygen; dye-sensitized photooxidation of several phenols; and photoinhibition of Escherichia coli.
MFO activity in carp (Cyprinus carpio) exposed to treated pulp and paper mill effluent in lake coleman, Victoria, Australia, in relation to AOX, EOX, and muscle PCDD/PCDF
Authors: Ahokas J.T. , Holdway D.A. , Brennan S.E. , Goudey R.W. , Bibrowska H.B. 
Published: March 2010

Abstract
European carp (Cyprinus carpio) exposed to highly treated pulp mill effluent in Lake Coleman, a shallow-water lake in southern Victoria, Australia, had significantly elevated hepatic microsomal EROD levels relative to reference fish from a nearby unexposed water body (Dowds and Heart morasses). Mean hepatic microsomal EROD activity appeared to be correlated with site adsorbable organic halogen (AOX) levels, with a simple linear regression yielding the equation Y = 0.059X+ 1.415 (r2 = 0.93, n = 5), where Y is mean EROD activity in nanomoles per minute per milligram and X is mean AOX concentration in micrograms per liter. Mean liver EROD activity was poorly related with fish muscle-tissue extractable organic halogen (EOX) and sediment EOX concentrations. Hepatic microsomal EROD activity also appeared to be correlated with the low levels of PCDD/PCDFs measured in carp muscle (1.0-4.0 ppt TCDD international toxic equivalents (TEs) in effluent-exposed fish muscle compared to 0.48-0.64 ppt TEs in reference fish muscle). Simple linear regression of mean EROD activity in carp liver with the mean fish muscle dioxin content yielded the equation Y= 6.514X+ 5.754 (n = 4, r2 = 0.88), where Y is mean EROD activity in nanomoles per minute per milligram and X is mean dioxin concentration in ppt of TCDD TEs. Hepatic microsomal ECOD activity, however, was not significantly different at any exposure site from the reference sites. Overall, Lake Coleman contained between 4.5 and 9.3 times the water AOX levels, 0.8 and 13.7 times the sediment EOX levels, 1.5 and 2.2 times the carp muscle-fat EOX levels, 5.0 and 5.3 times the carp whole-muscle TCDD toxic equivalents, and 6.5 times the carp fat TCDD toxic equivalents, compared to the Dowds and Heart morass reference samples. Within Lake Coleman, mean liver microsomal EROD activity levels were 2.3 to 6.3 times higher than the Dowds and Heart reference sites, respectively. Tissue concentrations of PCDD/PCDF and water AOX levels reduced with increasing distance from the effluent point source. Carp liver microsomal EROD represented a good biomarker of exposure to low levels of organochlorine contaminants from well-treated pulp mill effluent.