bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytotoxicity of chlorinated aliphatics to hybrid poplar (Populus deltoides × nigraDN34)
Authors: Dietz Annette C , Schnoor Jerald L 
Published: March 2010

AbstractEffects of a series of chlorinated ethenes and ethanes on hybrid poplar (Populus deltoides × nigra DN34) were assessed in laboratory experiments. Poplar cuttings were grown in sealed reactors with hydroponic solutions and were exposed to a chlorinated solvent for a period of two weeks. Exposure concentrations ranged from 0 to 0.4 mM for perchloroethylene to 0 to 8.4 mM for 1,1-dichloroethane. Effects were assessed by gravimetrically monitoring transpiration and measuring change in cutting mass. The zero-growth concentrations of the chemicals tested were 0.3 mM perchloroethylene, 0.9 mM trichloroethylene, 0.9 mM 1,1,2,2-tetrachloroethane, 2.0 mM 1,1,1-trichloroethane, 2.3 mM 1,1,2-trichloroethane, 4.8 mM trans-dichloroethylene, 5.6 mM 1,1-dichlor-oethylene, 6.0 mM cis-dichloroethylene, and 10.7 mM 1,1-dichloroethane. Adverse effects were found to increase with increasing number of chlorine atoms within a homologous series of ethenes or ethanes. Ethenes were more toxic than similarly chlorinated ethanes.
Response of bobwhite quail and gray-tailed voles to granular and flowable diazinon applications
Authors: Wang Guiming , Edge W Daniel , Wolff Jerry O 
Published: March 2010

AbstractWe used gray-tailed voles (Microtus canicaudus) and northern bobwhite quail (Colinus virginianus) as experimental model species to field test whether small mammals and birds respond differently to equivalent concentrations of a pesticide applied in granular and flowable formulations. In mid-May 1998, we placed voles into 15, 0.2-ha enclosures planted with a mixture of pasture grasses. In mid-July, we placed quail into the same enclosures with the voles. In late July, we applied the organophosphorus insecticide diazinon in five treatments; a control (all habitats sprayed with water), liquid formulation of diazinon at 0.55 kg/ha, liquid formulation of diazinon at 1.11 kg/ha, broadcast of granular diazinon at 1.11 kg/ha, and broadcast of granular diazinon at 2.22 kg/ha. The diazinon treatment in liquid and granular formulations did not depress population size or growth rate, or survival rate of voles. We found a significant difference in the survival rate of the quail between the controls and treatments; granular diazinon caused a measurable decline of quail survival, whereas the liquid application at an equivalent rate did not significantly affect quail survival. Analysis of our results suggests that ground-feeding birds are more susceptible to granular insecticides than flowable applications, but voles were not susceptible to either formulation at the rate we used.
Adding magnesium to the silver-gill binding model for rainbow trout (Oncorhynchus mykiss)
Authors: Schwartz Melissa L , Playle Richard C 
Published: March 2010

Abstract
Rainbow trout (Oncorhynchus mykiss; 2–17 g) were exposed to approximately 0.1 μM silver as AgNO3 for 3 to 4 h in synthetic, ion-poor water (20 μM Ca, 100 μM Na, 150 μM Cl, pH 7) to which was added Mg, Ca, or thiosulfate (S2O3). Gills were extracted and assayed for Ag using graphite furnace atomic absorption spectrophotometry. Up to 210 mM Mg (four fold the concentration of Mg in seawater) did not reduce accumulation of Ag by trout gills. The conditional equilibrium stability constant (K) for Mg at silver-binding sites on the gills was calculated to be log KMg-gillAg = 3.0, or approximately half-as-strong binding as for Ca at these sites. The inclusion of the Mg-gill stability constant into the original Ag-gill binding model increases the flexibility of the model, although the competitive effects of Mg are only important in sodium-poor systems.
Structure–activity relationship study on the bioreduction of AZO dyes by Clostridium paraputrificum
Authors: Moir David , Masson Sheila , Chu Ih 
Published: March 2010

Abstract
Seven commercially available, structurally related azo dyes have been bioreduced by the anaerobic bacterium Clostridium paraputrificum. The rates of reduction of these dyes were found to vary between 24 and 74 nmoles reduced/mg protein/h. Acid red 1 and desmethyl acid red 106 were found to be the most readily reduced, while chromotrope 2R and cibacron brilliant red 3B-A were reduced at the slowest rates. The differences in reduction rates can be rationalized on the basis of structural differences and are consistent with the possible intermediacy of low molecular-weight electron carriers as the mediators of reduction. The incorporation of electron-withdrawing groups into the dyes, even if remotely placed, was found to increase the rate of reduction of dyes under controlled conditions, supporting the inversely proportional relationship between the electron density of the azo bond and the ease of bioreduction.
Differential induction of glutathione S-transferases in the clamruditapes decussatusexposed to organic compounds
Authors: Hoarau Pascal , Gnassia-Barelli Mauricette , Romeo Michèe , Girard Jean-Pierre 
Published: March 2010

AbstractStudies of glutathione S-transferase (GST) induction were performed in the Mediterranean clam Ruditapes decussatus after controlled exposure to organics in holding tanks. Clams were treated with phenobarbital (PB), benzo[a]pyrene (BaP), and 2,2-bis-(p-chlorophenyl)-1,1-dichlorethylene (p,p′-DDE). Three different substrates, i.e., 1-chloro-2,4-dinitrobenzene (CDNB), ethacrynic acid (ETHA), and paranitrobenzene chloride (PNBC), were used to determine GST activities in order to distinguish the isoenzymes induced by contamination. The isoforms conjugating ETHA were significantly induced by treatment with PB and BaP whereas exposure to p,p′-DDE induced isoforms conjugating CDNB and ETHA. An antibody against affinity-purified GSTs from R. decussatus was prepared by injection into rabbit. The serum containing the antibody gave a positive reaction with both the purified GSTs from R. decussatus and the low molecular weight GSTs from rat. Subcellular fractions from both control and treated animals were analyzed by Western blot. Cytosolic extracts from clams contaminated with PB and p,p′-DDE showed a 24-kDa band in addition to the 26-kDa band recognized by the antibody. Results of these studies suggest that, in R. decussatus, organics may induce GSTs belonging to the π class.
Effects of chronic Cd exposure via the diet or water on internal organ-specific distribution and subsequent gill Cd uptake kinetics in juvenile rainbow trout (Oncorhynchus mykiss)
Authors: Szebedinszky Cheryl , McGeer James C , McDonald D Gordon , Wood Chris M 
Published: March 2010

AbstractNew regulatory approaches to metal toxicity (e.g., biotic ligand model [BLM]) focus on gill metal binding and tissue-specific accumulation of waterborne metals; the dietary route of exposure and dietary/waterborne interactions are not considered, nor are the consequences of chronic exposure by either route. Therefore, we studied the effect of the same gill Cd load (∼2.5 μg/g), achieved by a chronic, 30-d exposure to Cd either via the diet (1,500 mg/kg) or the water (2 μg/L), on tissue-specific Cd distribution and subsequent uptake of waterborne Cd in juvenile rainbow trout (Oncorhynchus mykiss). These two exposure regimes resulted in a branchial Cd load that had been taken up across either apical gill membranes (waterborne Cd) or basolateral gill membranes (through the bloodstream for dietary Cd). The BLM characteristics of the gills (i.e., short-term Cd uptake kinetics) were altered: affinity (log KCd-Gill [95% confidence level]) decreased from 7.05 (6.75–8.76) for control to 6.54 (6.32–7.03) for waterborne Cd and 5.92 (5.83–6.51) for dietary Cd, whereas binding capacity (Bmax) increased from 3.12 (2.14–4.09) to 4.80 (3.16–6.43) and 5.50 (2.86–8.17) nmol·g−1 for control, waterborne, and dietary Cd, respectively. Fish exposed to dietary Cd accumulated a much greater overall chronic Cd body burden relative to fish exposed to waterborne Cd or control fish. The carcass accumulated the greatest percentage of total body Cd in control and waterborne-exposed fish, whereas the intestinal tissue accumulated the greatest percentage in dietary-exposed fish. Tissue-specific Cd burdens were highest in the kidney in both dietary and waterborne treatments. We conclude that chronic Cd exposure alters Cd uptake dynamics, and that the route of Cd exposure, whether waterborne or dietary, results in differences of internal Cd accumulation and branchial Cd uptake characteristics. These factors should be considered in future BLM development.
Separation and characterization of gall bladder bile metabolites from speckled trout,Salvelinus fontinalis, exposed to individual polycyclic aromatic compounds
Authors: Leonard James D , Hellou Jocelyne 
Published: March 2010

AbstractSpeckled trout, Salvelinus fontinalis, were orally exposed to individual polycyclic aromatic compounds (PACs) represented by benzo[a]pyrene, carbazole, chrysene, dibenzofuran, dibenzothiophene, fluorene, phenanthrene, and pyrene. Fish were sacrificed 7 d after exposure and the gall bladder removed for bile analysis. High pressure liquid chromatography (HPLC) with fluorescence (F) and ultraviolet (UV) detection was used to determine the presence of PAC derivatives in the bile without pretreatment. Glucuronide conjugates were predominant in all exposures with variable amounts (0–53%) of phenols and starting material. Identification of compounds was confirmed by selective extraction of less polar nonconjugated PACs and enzymatic hydrolysis of water-soluble material. This was followed by HPLC and/or gas chromatography-mass spectrometry (GCMS) characterization of the produced phenols. Total metabolite levels varied widely among compounds.
Polycyclic aromatic hydrocarbons, aliphatic hydrocarbons, trace elements, and monooxygenase activity in birds nesting on the North Platte River, Casper, Wyoming, USA
Authors: Custer Thomas W , Custer Christine M , Dickerson Kimberly , Allen Kenneth , Melancon Mark J , Schmidt Larry J 
Published: March 2010

Abstract
Tree swallow (Tachycineta bicolor) and house wren (Troglodytes aedon) eggs and chicks were collected near a refinery site on the North Platte River, Casper, Wyoming, USA and at a reference site 10 km upstream. Total polycyclic aromatic hydrocarbon (PAH) concentrations in swallow and wren chicks were higher at the refinery site than at the reference site. Polycyclic aromatic hydrocarbon concentrations in sediment and chick dietary samples were consistent with these findings. The general lack of methylated PAHs in sediment, diet, and bird carcasses suggested that the PAHs were derived from combustion and not from petroleum. The predominance of odd-numbered aliphatic hydrocarbons and the low ratios (≤0.25) of pristane:n-C17 and phytane:n-C18 in chick and diet samples also suggested that swallow and wren chicks were not being chronically exposed to petroleum. Mean ethoxyresorufin-O-dealkylase and benzyloxyresorufin-O-dealkylase activities in tree swallow livers averaged nine times higher at the refinery site than at the reference site and were probably induced by exposure to PAHs. Trace element concentrations in eggs and livers of swallows and wrens were similar or greater at the reference site than at the refinery site. Selenium, strontium, and boron concentrations were elevated in eggs and livers of swallows and wrens at both the refinery and reference sites.
Kinetics of polychlorinated biphenyl dechlorination and growth of dechlorinating microorganism
Authors: Rhee G.-Yull , Sokol Roger C , Bethoney Charlotte M , Cho Young-Cheol , Frohnhoefer Robert C , Erkkila Ted 
Published: March 2010

Abstract
The present study has investigated a correlation between the kinetics of polychlorinated biphenyl (PCB) dechlorination and the growth of dechlorinating microbial populations. Microorganisms were eluted from Aroclor® 1248-contaminated St. Lawrence River (NY, USA) sediments and inoculated into clean sediments spiked with Aroclor 1248 at 10 concentrations ranging from 0 to 3.12 μmol/g sediment (0–900 ppm). The time course of PCB dechlorination and population growth were concurrently determined by congener-specific analysis and the most probable number technique, respectively. The specific growth rate was a saturation function of PCB concentrations above the threshold concentration (0.14 μmol/g sediment, or 40 ppm), below which no dechlorination or growth of dechlorinations were observed. The maximum growth rate was 0.20/d with a half-saturation constant of 1.23 μmol/g sediment. The yield of dechlorinating microorganisms showed a peak at 0.70 μmol/g sediment (200 ppm), with a value of 10.3 × 1012 cells/mol Cl removed, and decreased below and above this concentration. The dechlorination rate (μmol Cl removed/g sediment/d) was a linear function of Aroclor concentration. Both the log of this rate and the maximum level of dechlorination were significantly correlated with growth rate. The biomass-normalized dechlorination rate (μmol Cl removed/g sediment/cell/d) was first order because of the exponential manner of the population growth. The first-order rate constant was a saturation function of Aroclor concentrations, with a maximum of 0.24/d (a half-life of 2.9 d) and a half-saturation constant of 1.18 μmol/g sediment, which are similar to the constants for growth. These results indicate that the dechlorination rate is tightly linked to the population growth of dechlorinating microorganisms.
Runoff simulation with particle-bound fenvalerate in multispecies stream microcosms: Importance of biological interactions
Authors: Schulz Ralf , Liess Matthias 
Published: March 2010

Abstract
Multispecies stream microcosms were used to test the toxicity of the pyrethroid fenvalerate (FV) associated with suspended particles in order to simulate a typical runoff exposure scenario. Stream microcosms were exposed for 1 h in triplicate to 0.0, 13.6, 136, or 1,365 μg/kg FV and effects were monitored for 93 d. Experimental design allowed for detection of interspecific effects on the emergence and thus survival of the caddisfly species Limnephilus lunatus Curtis and of intraspecific effects on the spatial distribution of adult and juvenile Gammarus pulex L. (Amphipoda). Exposure at 136- and 1,365 μg/kg resulted in a significant acute increase in drift. Survival of L. lunatus was significantly reduced in the 1,365-μg/kg treatment during single-species exposures. When other species were present, survival of L. lunatus was significantly reduced at 136 μg/kg. A similar increase in test system susceptibility was observed in relation to the spatial distribution of G. pulex. Juvenile individuals avoided areas with high numbers of adult amphipods, which may prey on the juveniles. This avoidance was significant in the control and the 13.6-μg/kg treatment but did not occur at higher levels of exposure. This study highlights the ecotoxicological importance of field-relevant levels of particle-associated hydrophobic chemicals that transiently increase during runoff events. Interspecific and intraspecific interactions can alter the test results; i.e., significant lethal and sublethal effects are measurable at FV levels approximately an order of magnitude lower than when biological interactions are excluded.
Effects of atrazine on embryos, larvae, and adults of anuran amphibians
Authors: Allran John W , Karasov William H 
Published: March 2010

Abstract
We examined the effects of atrazine (0–20 mg/L) on embryos, larvae, and adult anuran amphibian species in the laboratory. Atrazine treatments did not affect hatchability of embryos or 96-h posthatch mortality of larvae of Rana pipiens, Rana sylvatica, or Bufo americanus. Furthermore, atrazine had no effect on swimming speed (measured for R. pipiens only). However, there was a dose-dependent increase in deformed larvae of all three species with increasing atrazine concentration. In adult R. pipiens, atrazine increased buccal and thoracic ventilation, indicating respiratory distress. However, because atrazine had no affect on hemoglobin, this respiratory distress was probably not indicative of reduced oxygen-carrying capacity of the blood. Frogs exposed to the highest atrazine concentration stopped eating immediately after treatment began and did not eat during the 14-d experiment. However, no decreases in mass were measured even for frogs that were not eating, probably because of compensatory fluid gain from edema. Atrazine concentrations found to be deleterious to amphibian embryos and adults are considerably higher than concentrations currently found in surface waters in North America. Therefore, direct toxicity of atrazine is probably not a significant factor in recent amphibian declines.
Effects of nonylphenol, bisphenol a, and their mixture on the viviparous swordtail fish (Xiphophorus helleri)
Authors: Kwak Hyeong-Il , Bae Mi-Ok , Lee Moon-Han , Lee Yong-Soon , Lee Bum-Joon , Kang Kyung-Sun , Chae Chan-Hee , Sung Ha-Jung , Shin Jin-Sup , Kim Jin-Hwa , Mar Woong-Cheon , Sheen Yhun-Yong , Cho Myung-Haing 
Published: March 2010

Abstract
A number of fish species have been used for studies on endocrine disrupting chemicals (EDCs). However, despite the widespread use of oviparous fish, relatively little attention has been given to viviparous species. This study investigated the effects of EDCs in a viviparous fish and examined the possible usefulness of the fish as an alternative model for the studies on EDCs. Swordtails (Xiphophorus helleri) were exposed to nonylphenol (NP), bisphenol A (BPA), and their mixture. Both short-term (3-d) and relatively long-term (60-d) exposures were carried out using adult male and 30-d-old juvenile fish, respectively. Following the short-term exposure, both NP and BPA caused vitellogenin mRNA expression. Flow cytometric analysis and terminal deox-ynucleotidyl transferase assay on the testes of treated fish indicated reproductive damage. Histopathological analysis found degenerative and necrotic cells in seminiferous tubules following the exposure to 100 ppb NP. The testes with lesions were also associated with highly suppressed spermatogenesis. Following the long-term exposure, both NP and BPA exposures significantly affected the growth of swordtails. In all cases, the results showed that the mixture was always more potent than a single chemical and that swordtail fish can be a useful model for the study of endocrine disruptors.
Toxicity and bioaccumulation of ddt in freshwater amphipods in exposures to spiked sediments
Authors: Lotufo Guilherme R , Landrum Peter F , Gedeon Michelle L 
Published: March 2010

AbstractThe amphipods Hyalella azteca and Diporeia spp. were exposed to sediments dosed with dichlorodiphenyltrichloroethane (DDT), and the toxicity and toxicokinetics were determined. The toxicity was evaluated with the equilibrium partitioning (EqP) and critical body residue approaches. The DDT in the sediments degraded during the equilibration period prior to organism exposure. Thus, the toxicity using EqP pore-water toxic units (TUs) was evaluated for DDT and its degradation product, dichlorodiphenyld-ichloroethane (DDD), as the ratio of the predicted interstitial water concentration divided by the water-only LC50 values. The sum of TUs (ΣTU) was assumed to best represent the toxicity of the mixture. For H. azteca, the 10-d LC50 was 0.98 and 0.33 ΣTU for two experiments. For Diporeia spp., no toxicity was found in the first experiment with up to 3 ΣTU predicted in the interstitial water. However, in the second experiment, the 28-d LC50 was 0.67 ΣTU. These data suggest that the EqP approach approximately predicts the toxicity for the combination of DDT and DDD in sediment, provided a toxic unit approach is employed. The critical body residue approach also used TUs because DDT is biotransformed by H. azteca and because of the dual exposure to DDT and DDD. Because biotransformation was only determined in the second experiment, the critical body residue approach could only be evaluated for that case. The TUs were calculated as the ratio of the concentration in the live amphipods divided by the respective LR50 (residue concentration required to produce 50% mortality) values. The LR50 was 1.1 ΣTU for H. azteca for the 10-d exposure and 0.53 for Diporeia spp. after a 28-d exposure. Thus, this approach was also quite successful in predicting the toxicity. The accumulation and loss rates for H. azteca were much greater than for Diporeia spp. Thus, 10-d exposures represent steady-state conditions for H. azteca, while even at 28-d, the Diporeia spp. are not at steady state.
Toxicity-based criteria for the evaluation of textile wastewater treatment efficiency
Authors: Rosa Edson V. Cordova , Simionatto Edesio Luiz , de Souza Sierra Maria Marta , Bertoli Savio Leandro , Radetski Claudemir Marcos 
Published: March 2010

Abstract
Brazilian textile mills import wastewater treatment technologies, performances of which are generally evaluated only on a physicochemical basis. Thus, a battery of bioassays was used to evaluate the performance of an ozonation system to treat textile effluents. Comparative toxicological profiles for bacteria (Vibriofischeri), algae (Scenedesmus subspicatus), daphnia(Daphnia magna), fish (Poecilia reticulata), and plants (soybean—Glycine max, rice—Oryza sativa, and wheat—Triticum aestivum), as well as genotoxic effects (Viciafaba micronucleus assay), are presented for both raw and ozonated textile effluents. The relative sensitivity of bioassays (or end points) to textile effluents found in this study in decreasing order was plant enzymes &gt; bacteria &gt; algae ≈ daphnids ≈ plant biomass ≈ germination rate &gt; fish. No significant genotoxic effect was found. We have concluded that ozonation was relatively effective in reducing toxicity of textile effluents. Bioassays used in this study proved to be sensitive and reliable tools for determining the toxicity of industrial effluents, and thus they can be used to evaluate emerging technology efficiency.
Cadmium accumulation by invertebrates living at the sediment–water interface
Authors: Hare Landis , Tessier André , Warren Lesley 
Published: March 2010

Abstract
Benthic animals can take up trace metals both from the sediment compartment in which they burrow and from the water column compartment above their burrows (we define both compartments as containing water and particles). If criteria for the protection of benthic animals are based on metal concentrations in one of these two compartments, then it should first be demonstrated that the majority of the metal taken up by these animals comes from the given compartment. To determine whether benthic animals take up the majority of their cadmium (Cd) from the sediment compartment, we created a Cd gradient in lake sediment and compared Cd accumulation by the invertebrates colonizing these sediments with Cd concentrations in the sediment compartment. On the basis of this relationship and using a bioaccumulation model, we estimate that indigenous benthic invertebrates take up the majority of their Cd from the water column compartment. The results of our experiment are similar to those from a previous study conducted on a different benthic community in a larger lake. Taxa common to both lakes obtained similar proportions of their Cd from the water column compartment, suggesting that Cd accumulation by the same species will be constant across lakes of differing size and chemistry. Our results strengthen the argument that the protection of benthic communities from metal pollution should consider metal in both the water column and sediment compartments. In this regard, the AVS model, which considers only sedimentary metals, was more effective in predicting Cd concentrations in pore waters than those in most animal taxa. We suggest that measurements of vertical chemical heterogeneity in sediments and of animal behavior would aid in predicting the bioaccumulation and effects of sedimentary pollutants.