bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the duration and timing of dietary methyl parathion exposure on bobwhite reproduction
Authors: Bennett Richard S. , Shiroyama Tamotsu , Bentley Ray , Bennett Jewel K. 
Published: March 2010

Abstract
Two northern bobwhite (Colinus virginianus) reproduction tests were conducted concurrently to evaluate how the duration and time of initiation of methyl parathion exposure affected dose-response relationships of reproductive parameters. In the long-term exposure test, pairs of adult bobwhite were fed methyl parathion-amended diets (0, 7, 10, 14, 20 or 28 ppm) for 25 weeks: 10 weeks prior to the onset of laying, 6 weeks as they came into laying condition and 9 weeks during egg laying. In the short-term exposure test, quail received amended diets (0, 10, 14, 20, 28 or 40 ppm) for only three weeks during the egg laying period, followed by a three-week posttreatment period. Fourteen birds died in the long-term test, compared to two in the short-term test. Significant dose-related reductions in daily food consumption, egg production and the number of 14-d-old chicks were observed in both tests during the treatment periods. No dose-related effects on fertility, hatch-ability or chick weights were detected. In the long-term test, there were dose-related decreases in adult body weight, brain and serum cholinesterase activity and female serum calcium concentrations. Cholinesterase and calcium were not measured in the short-term test. Eggshell weights were significantly decreased in both tests, but a dose-related decrease in eggshell strength and thickness was detected only in the short-term test. During the posttreatment period of the short-term test, no dose-related effects on reproductive parameters were observed, except that egg production did not recover until the third week after treatment. Except for the number of adult mortalities, all dose-related effects observed in the long-term exposure test also were observed in the short-term test. The short-term test design had two advantages that reduced variability unrelated to the chemical treatments: infertile and incompatible pairs could be removed from the experiment and pretreatment values could be obtained to serve as controls for each pair.
Effects of dietary methyl parathion on northern bobwhite egg production and eggshell quality
Authors: Bennett Jewel K. , Bennett Richard S. 
Published: March 2010

Abstract
There is a need to develop avian reproduction tests that reflect more realistic exposure scenarios for short-lived pesticides, like organophosphorus and carbamate compounds. The effect of a short-term dietary methyl parathion exposure on northern bobwhite (Colinus virginianus) egg production and shell quality was investigated. Hens in egg production were fed either a methyl parathion diet (0, 14, 20, 28 or 40 ppm) or a pair-fed diet (PF28 and PF40 received the same daily allotment of control feed on a g/kg/d basis as the 28 or 40 ppm-treated hen with whom she was paired) for 8 d. Daily food consumption was significantly reduced in all treatment groups and inversely related to chemical concentration. However, actual chemical consumption was similar for all methyl parathion-treated groups. Body weight, egg production, egg weight and eggshell strength, thickness and weight were reduced in the methyl parathion groups in a dose-related manner. Similar responses were observed in the pair-fed groups, indicating that effects were associated with a pesticide-induced reduction in food consumption. The dietary methyl parathion exposure impacted bobwhite egg production within 3 to 4 d and eggshell quality within 1 d of the onset of treatment.
Toxicity of cadmium in sediments: The role of acid volatile sulfide
Authors: Di Toro Dominic M. , Mahony John D. , Hansen David J. , Scott K. John , Hicks Michael B. , Mayr Suzanne M. , Redmond Michele S. 
Published: March 2010

Abstract
The toxicity of chemicals in sediments is influenced by the extent that chemicals bind to the sediment. It is shown that acid volatile sulfide (AVS) is the sediment phase that determines the LC50 for cadmium in the marine sediments tested. Although it is well known that metals can form insoluble sulfides, it apparently has not been recognized that AVS is a reactive pool of solid phase sulfide that is available to bind with metals. Amphipod sediment toxicity tests were conducted in the laboratory and the observed amphipod LC50s on a normalized cadmium concentration basis, [Cd]/[AVS], is the same for sediments with over an order of magnitude difference in dry weight normalized cadmium LC50s.
Because other toxic metals also form insoluble sulfides, it is likely that AVS is important in determining their toxicity in sediments as well. Most freshwater and marine sediments contain sufficient acid volatile sulfide for this phase to be the predominant determinant of toxicity. The other sorption phases are expected to be important only for low AVS sediments, for example, fully oxidized sediments. From the point of view of sediment quality criteria the other sorption phases would be important for metals with large partition coefficients and large chronic water quality criteria.
Validation of a four-day Ceriodaphnia toxicity test and statistical considerations in data analysis
Authors: Masters Julie A. , Lewis Michael A. , Davidson Daniel H. , Bruce Robert D. 
Published: March 2010

Abstract
This study evaluated the technical feasibility of a shorter alternative to the U.S. Environmental Protection Agency (EPA)-recommended 7-d chronic toxicity test with Ceriodaphnia dubia. The results of 4-d and 7-d Ceriodaphnia dubia toxicity tests, conducted concurrently, were compared using treated municipal effluent, metals, PCP, ethylene glycol, phenol and surfactants. The experimental technique was similar for both studies with the exception of the duration and age of the test species at test initiation. The 4-d static-renewal test was initiated with 3-day-old Ceriodaphnia dubia, and 1-day-old organisms were used in the 7-d tests. The chronic values of the replicated studies, based on survival and young production, were within a factor of two in approximately 70% of the total tests conducted and in all tests conducted with municipal effluent. Based on the available results, the 4-d toxicity study appears to be a technically valid alternative to the EPA-recommended 7-day test, particularly for treated municipal effluent. An important factor in toxicity testing is the use of valid statistical procedures. The validity of the various methods for Ceriodaphnia dubia depends upon their appropriate use; however, it is difficult to justify the widespread use of multiple comparison methods, particularly Dunnett's procedure.
Acute physiological stress responses of juvenile coho salmon (Oncorhynchus kisutch) to sublethal concentrations of garlon 4®, garlon 3a® and vision® herbicides
Authors: Janz David M. , Farrell Anthony P. , Morgan J. D. , Vigers Gary A. 
Published: March 2010

Abstract
Juvenile coho salmon (Oncorhynchus kisutch) were exposed for 4 h to sublethal concentrations of the herbicides Garlon 4®, Garlon 3A®, and Vision®. Trials were performed in a closed-system respirometer that measured oxygen consumption of fish prior to and during a 4-h exposure. At the end of the exposure period, plasma glucose and lactate concentrations, hematocrit, and leucocrit were measured as indicators of acute physiological stress. There were no biologically significant indications of acute physiological stress in fish exposed to Garlon 4, Garlon 3A, or Vision at 5 to 80% of the 96-h LC50 concentrations. The results suggest that threshold herbicide concentrations causing physiological stress in short-term exposure (4 h) in juvenile coho salmon may be higher than the 96-h LC50 value for those herbicides. It was concluded that sublethal concentrations of Garlon and Vision herbicides do not induce significant physiological stress responses in juvenile coho salmon during a 4-h exposure period.
An aquatic environmental safety assessment of linear alkylbenzene
Authors: Gledhill William E. , Saeger Victor W. , Trehy Michael L. 
Published: March 2010

Abstract
Linear alkylbenzene (LAB), the parent material from which the detergent surfactant linear alkylbenzene sulfonate (LAS) is manufactured, has the potential to enter the environment from several sources. Solubility, vapor pressure and soil partition measurements indicate that LAB would be distributed in air or adsorbed to soil or sediment. The material does not accumulate to significant levels in fish (BCF = 35) or undergo chemical or photochemical degradation in screening studies. LAB is readily biodegradable in natural waters with half-lives for various isomers and homologs in the 4- to 9-day range. LAB is not acutely toxic to a variety of aquatic species, other than Daphnia magna, within its water solubility range. For Daphnia, chronic studies in clean water systems indicate both growth and reproduction to be affected in the 10 to 20 μg/L range. LAB is substantially removed by typical sewage treatment plants. Receiving waters collected from sites receiving low sewage effluent dilution generally contain less than 1 μg/L. Based on the ratio of the chronic no-effect level for Daphnia to the environmental concentration, the conservative nature of selected monitoring sites i.e., providing low sewage effluent dilution) and the fact that LAB partitions strongly to particulates in the water column, adequate environmental safety margins exist for LAB.
Iodide binding by humic acid
Authors: Huang Tien-Shang , Lu Fung-Jou 
Published: March 2010

Abstract
Iodide binding by humic acid was studied. The reaction was dose, temperature and pH dependent. A maximum binding of 88% was reached with 2 mg humic acid in 0.15 M Tris buffer. The efficiency of iodide binding by the buffer becomes higher whenever the buffer is slightly alkaline. Iodide binding by humic acid at 60°C is more efficient than that at room temperature or 4°C. The reaction was very rapid and reached equilibrium in 2 h. There are two binding sites for iodide in humic acid. The iodide binding by humic acid is inhibited by depleting of oxygen. The reaction was also inhibited by superoxide dismutase, catalase, thiourea, glutathione and dithiothreitol, but butylated hydroxytoluene and ascorbic acid did not inhibit it. In conclusion: (a) Humic acid can bind iodide efficiently in various buffers, (b) the binding is probably a reaction of oxidation reduction, (c) free radicals are involved in the reaction and (d) free radicals are present in the humic acid.
In vitro cytotoxicity of chlorophenols to goldfish GF-scale (GFS) cells and quantitative structure-activity relationships
Authors: Saito Hotaka , Sudo Masato , Shigeoka Tadayoshi , Yamauchi Fumio 
Published: March 2010

AbstractGF-Scale (GFS) cells, a fibroblastic cell line derived from the scale of goldfish, were used for the determination of the cytotoxicity of chlorophenols (CPs) and the quantitative structure-activity relationships (QSAR) studies. As the cytotoxicity end point, the amount of neutral red retained by viable cells after exposure to chemicals was quantified. The sequence of cytotoxicity based on the concentration of chemicals that reduced uptake of neutral red by 50% (NR50) was penta-Cl (PCP) &gt; 2,4,5-Cl3 &gt; 2,3,4-Cl3 &gt; 2,3,4,6-Cl4 &gt; 3,5-Cl2 &gt; 3,4-Cl2 &gt; 2,4-Cl2 &gt; 2,5-Cl2 &gt; 2,3-Cl2 &gt; 2,4,6-Cl3 &gt; 3-Cl &gt; 4-Cl &gt; 2,6-Cl &gt; 2-Cl &gt; phenol. The in vitro cytotoxicity of these chemicals was found to be significantly correlated to their in vivo acute toxicity to aquatic species, and NR50 values were correlated with six physicochemical parameters of chlorophenols. Log Pow (n-octanol/water partition coefficient) gave the best correlation in simple linear regression analysis, as is frequently stated in toxicity studies with aquatic animals. Multiparametric linear regression equations yielded improved correlation coefficients and predictive capabilities, including the log Pow and pKa. These results suggest that in vitro fish cytotoxicity assays using the GFS cell lines are useful for ecotoxicity screening of aquatic pollutants.
Residue dynamics and effects of aluminum on growth and mortality in brook trout
Authors: Cleveland Laverne , Buckler Denny R. , Brumbaugh William G. 
Published: March 2010

Abstract
Brook trout (Salvelinus fontinalis) about 30 d old and weighing 0.2 g were exposed for 56 d to duplicated nominal pHs of 5.0, 6.0 and 7.2 in combination with nominal aluminum concentrations of 200 μ/L. At 56 d, each treatment group was transferred to water of the same pH without added aluminum and held for 28 d of depuration. Samples of fish were collected from each treatment for whole-body aluminum analyses on days 3, 7, 14, 28 and 56 of the exposure. During the depuration period, fish were sampled at 3, 7, 14 and 28 d for whole-body aluminum analyses. Mortality and pH were monitored daily in each treatment. The estimated time to 90% steady state for aluminum in the fish was 1.5 d at pH 5.3, 4.2 d at pH 6.1 and 1.7 d at pH 7.2. Estimated steady-state bioconcentration factors for aluminum, which were inversely related to pH, were 215 at pH 5.3, 123 at pH 6.1 and 36 at pH 7.2. The maximum observed factors were 232 at pH 5.3, 153 at pH 6.1 and 46 at pH 7.2. Brook trout eliminated aluminum from tissues more rapidly at pH 5.3 than at pH 6.1 and 7.2. Mortality was generally higher in brook trout exposed to aluminum at pH 5.3 than in those exposed at pH 6.1 and 7.2. Mortality was lowest (&lt;3%) for the fish exposed to aluminum at pH 7.2.
Modeling ceriodaphnia toxicity in the Naugatuck river II. Copper, hardness and effluent interactions
Authors: Di Toro Dominic M. , Hallden James A. , Plafkini James L. 
Published: March 2010

Abstract
Previous studies have shown that whole toxicity in the Naugatuck River, Connecticut, does not exhibit additive behavior. The nature of whole toxicity in the river is reassessed using available water chemistry data to identify the primary toxicants and quantify their interactions in the river. Two major classes of toxicity—copper from industrial discharges and toxicity from publicly owned treatments works (POTWs)—are identified. A water quality model of whole toxicity is constructed, based on the analysis of specific toxicant data. The results are in closer agreement with observed instream toxicity than the previous model which assumed strict additivity of effluent toxicity.
Abiotic and biotic factors influencing in situ trace metal levels in macroinvertebrates in freshwater ecosystems
Authors: van Hattum Bert , Timmermans Klaas R. , Govers Harrie A. 
Published: March 2010

Abstract
We examined the potential of a multiple regression model, including both biotic and abiotic variables, to predict trace metal levels (Cd, Pb, Cu and Zn) in benthic invertebrate communities from various aquatic habitats in The Netherlands. Variables included in the regression model and their relative contribution to the predictive power appeared to be highly element-specific. Sediment- and water-related abiotic variables were especially important for the prediction of Cd, Pb and, to a lesser extent, Zn. For the essential trace metals, the biotic variables such as the presence of hemocyanin (in the case of Cu) and trophic level (Zn) appeared to have a dominant influence. Species-body weight showed a negative log-linear relationship with trace metal levels of Pb and, to a lesser extent, Cu and Cd. For all metals, significant coefficients of multiple correlation were observed. The variance in invertebrate trace metal levels explained by the model ranged from 25% for Zn to 37% for Cd and Cu. For all trace metals, the introduction of biotic variables resulted in a significant increase in predictive power (p &lt; 0.02), compared to the use of only abiotic predictors. Marked differences in predictive power of the model were observed among various species or taxonomic categories. For several species remarkably significant relationships were revealed, indicating the potential usefulness of the organisms for biological monitoring and further modeling studies.
Cyclic peptide hepatotoxins from freshwater cyanobacterial (blue-green algae) waterblooms collected in Central China
Authors: Zhang Qing-Xue , Yu Min-Juan , Li Shang-Hao , Carmichael Wayne W. 
Published: March 2010

AbstractToxic cyanobacteria (blue-green algae) waterblooms have been found in several Chinese water bodies since studies began there in 1984. Waterbloom samples for this study contained Anabaena circinalis, Microcystis aeruginosa and Oscillatoria sp. Only those waterblooms dominated by Microcystis aeruginosa were toxic by the intraperitoneal (i.p.) mouse bioassay. Signs of poisoning were the same as with known hepatotoxic cyclic peptide microcystins. One toxic fraction was isolated from each Microcystis aeruginosa sample. Two hepatotoxic peptides were purified from each of the fractions by high-performance liquid chromatography and identified by amino acid analysis followed by low and high resolution fast-atom bombardment mass spectrometry (FAB-MS). LD50 i.p. mouse values for the two toxins were 245 μg/kg (Toxin A) and 53 μg/g (Toxin B). Toxin content in the cells was 0.03 to 3.95 mg/g (Toxin A) and 0.18 to 3.33 mg/kg (Toxin B). The amino acid composition of Toxin A was alanine [1], arginine [2], glutamic acid [1] and β-methylaspartic acid [1]; for Toxin B it was the same, except one of the arginines was replaced with a leucine. Low- and high-resolution FAB-MS showed that the molecular weights were 1,037 m/z (Toxin A) and 994 m/z (Toxin B), with formulas of C49H76O12N13 (Toxin A) and C49H75O12N10 (Toxin B). It was concluded that Toxin A is microcystin-RR and Toxin B is microcystin-LR, both known cyclic heptapeptide hepatotoxins isolated from cyanobacteria in other parts of the world. Sodium borohydride reduction of microcystin-RR yielded dihydro-microcystin-RR (m/z = 1,039), an important intermediate in the preparation of tritium-labeled toxin for metabolism and fate studies.
Structure-activity relationships of chlorobenzenes using DNA measurement as a toxicity parameter in algae
Authors: Figueroa Ines Del C. , Simmons Milagros S. 
Published: March 2010

Abstract
This study investigated the effects of chlorobenzenes on the diatom Cyclotella meneghiniana using DNA measurement as a toxicity parameter and related toxicity to different physicochemical properties of chlorobenzenes. The organisms were exposed to chlorobenzene solutions for 48 h to obtain effective concentration (EC50) values (in terms of percent DNA reduction). The toxicity (EC50) increased with increasing degree of chlorination, as follows: monochlorobenzene (235.74 mg/L), dichlorobenzenes (23.33-51.88 mg/L), trichlorobenzenes (0.59-6.42 mg/L), tetra-chlorobenzenes (0.27-1.39 mg/L), pentachlorobenzene (0.008 mg/L) and hexachlorobenzene (0.002 mg/L). Quantitative structure-activity relationships were developed showing high correlations, as follows: water solubility (r2 = 0.96); molecular volume (r2 = 0.92); zero-order connectivity index (r2 = 0.92); second-order connectivity index (r2 = 0.92); molecular surface area (r2 = 0.92); octanol/water partition coefficient (r2 = 0.86); bioconcentration factor (r2 = 0.86); and inorganic/organic character (r2 = 0.83). A poor correlation, however, was obtained with the molecular negentropy index (r2 = 0.25). The toxic effect (EC50) was explained in terms of a partitioning process as a function of the aqueous solubility of the chlorobenzenes and was found to occur at similar degrees of exposure saturation.
Cadmium turnover in minnows (phoxinus phoxinus) preexposed to waterborne cadmium
Authors: Glynn Anders Wicklund , Olsson Per-Erik 
Published: March 2010

Abstract
The radioactive isotope 109Cd was used to study the turnover of Cd in minnows (Phoxinus phoxinus) preexposed to waterborne Cd. Three groups of fish were preexposed to 3 nM Cd for 0, 30 and 91 d before a 24-h 109Cd exposure (3 nM Cd). The effect of preexposure on the turnover of 109Cd in the fish was studied during a 64-d post-tracer exposure period at 3 nM Cd. The major effect of Cd preexposure on the 109Cd turnover was a decreased uptake of 109Cd into the gills. In the gill tissue, the 109Cd was retained by Cd binding ligands mainly in the cytosolic fraction. Preexposure decreased the percentage of 109Cd retained in a cytosolic high-molecular-weight fraction at the end of the tracer exposure. At the same time, an increased percentage of tracer was retained in a low-molecular-weight cytosolic fraction with high 109Cd content (Cd-BP), probably metallothionein (MT). This effect was not caused by an increased MT content in the preexposed fish. The liver, kidney, muscle and bone accumulated 109Cd, while the gills, head and skin eliminated tracer during the 64-d post-tracer exposure period. The 109Cd elimination and accumulation were not altered by the Cd preexposure. A large part of the tracer accumulated in the liver and kidney was detected in the Cd-BP fraction, and the MT content in the organs was not altered by the preexposure.
Fate and acute toxicity of bromoxynil esters in an experimental prairie wetland
Authors: Muir D. C. G. , Kenny D. F. , Grift N. P. , Robinson R. D. , Titman R. D. , Murkin H. R. 
Published: March 2010

Abstract
The partitioning, degradation and toxicity of a single spray application of a 1:1 mixture of bromoxynil octanoate (BO) and bromoxynil butyrate (BB) were studied in fifteen 0.01-ha ponds located in the Delta marsh area of Manitoba. Intensive sarnpling of two ponds treated at 2.5 μg/L and two treated at 50 μg/L (nominal concentrations) showed that BO and BB persisted in the surface microlayer (0–1 mm) of the water at levels 50- to 100-fold higher than the intended treatment level, with half-lives of 0.8 to 2.5 h. In subsurface waters (10–20 cm depth) the major forms of the herbicide were bromoxynil-phenol and its monobromo- analog (3-bromo-4-hydroxybenzonitrile; MBBP). Half-lives of the phenol averaged 9.2 d in ponds treated at 50 μg/L and 14.5 d in those receiving 2.5 μg/L. Low ng/g (dry wt.) levels of BO, BB, MBBP and bromoxynil-phenol were present in bottom sediments (0–2 cm depth) during the first 15 d posttreatment and declined to near detection limits (&lt;0.5 ng/g) by 120 d after spray application. Complete mortality of brook sticklebacks (Culaea inconstans), held in cages in subsurface waters, occurred within 24 h at the two highest treatment levels (nominal concentrations of 100 and 500 μg/L). Mortality of caged Hyalella azteca at the highest dose levels ranged from 85 to 95% at 50 h.
Effects of photoenhanced toxicity of anthracene on ecological and genetic fitness of daphnia magna: A reappraisal
Authors: Foran Jeffery A. , Holst Linda L. , Giesy John P. 
Published: March 2010

Abstract
Holst and Giesy [1] reported photoenhanced effects of anthracene exposure on reproduction of Daphnia magna in terms of total clutch size and survival over a 21-d period. A reappraisal of those experiments, using additional data regarding time to first brood, average size of first brood and the intrinsic rate of increase, rm, for exposures with and without anthracene and/or ultraviolet radiation (UVR), reveals that inferred impacts on genetic fitness as exemplified by rm are significant only for the highest exposure tested, whereas ecological fitness, measured by the time to first brood, was unimpaired at any combination of UVR and anthracene.