bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute toxicity and toxicokinetics of 4-heptylphenol in juvenile atlantic cod (Gadus morhua L.)
Authors: Tollefsen Knut-Erik , Ingebrigtsen Kristian , Olsen Anders Johny , Zachariassen Karl Erik , Johnsen Ståle 
Published: March 2010

Abstract
Heptylphenol has been detected in produced water from various oil production platforms in the Norwegian sector of the North Sea and may be of environmental concern due to hydrophobic properties and slow biodegradation in the marine environment. The n-octanol/water partition coefficient of 4-heptylphenol (4-HP) was estimated by a high-performance liquid chromatographic correlation analysis. Acute toxicity and toxicokinetics of 4-HP in juvenile Atlantic cod (Gadus morhua L.) were investigated in flow-through exposure systems using unlabeled and 14C-labeled 4-HP, respectively. The results show that 4-HP was moderately hydrophobic (log Kow = 4.5) and toxic to juvenile cod (96 h LC50 = 2.9 μmol/L). The toxicokinetics of 4-HP was calculated using a one-compartment first-order kinetic (1CFOK) model (k1 = 29.94 ± 1.83, k2 = 0.052 ± 0.011/h, t95 ≈ 58 h and t1/2 ≈ 13 h). The values obtained corresponded to a steady-state and kinetic bioconcentration factor (BCF) of 555 and 578, respectively. The distribution pattern of 4-HP (and/or metabolites) at steady state and after 96 h of recovery in uncontaminated seawater was dominated by the gastrointestinal system possibly owing to biotransformation and elimination through these organs. The results also revealed that neither 4-HP nor possible metabolites bind to macromolecules or tissue structures in the fish.
Structural influences of low-molecular-weight dissolved organic carbon mimics on the photolytic fate of atrazine
Authors: Hapeman Cathleen J , Bilboulian Susanna , Anderson Brent G , Torrents Alba 
Published: March 2010

Abstract
The fate of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was examined in the presence of dissolved organic carbon (DOC) mimics to discern the effect of the various structural characteristics of DOC with respect to direct photolysis and transformation via a photoinitiated nitrate-mediated hydroxy radical process (indirect photolysis). Experiments were conducted with coniferyl alcohol, 2-octanol, oxalic acid, pyrogallol, quinone, and salicylic acid. All mimics except octanol and coniferyl alcohol caused an increase in the atrazine degradation rate when no nitrate was present. A decrease in atrazine degradation in indirect photolysis was observed for coniferyl alcohol, octanol, pyrogallol, and salicylic acid, whereas the rate increased with oxalic acid and quinone. Examination of the product ratios showed a dependence of the chemical activity (photosensitizer, OH· radical scavenger or OH· generator) on structure. Results revealed that structural aspects of DOC, in addition to concentration, must be considered when predicting the photolytic fate of pesticides.
Comparison of in vitro submitochondrial particle and Microtox® assays for determining the toxicity of organotin compounds
Authors: Argese Emanuele , Bettiol Cinzia , Ghirardini Annamaria Volpi , Fasolo Matteo , Giurin Gianumberto , Ghetti Pier Francesco 
Published: March 2010

Abstract
The toxicity of 14 organotin compounds was investigated by means of two short-term in vitro bioassays, the submitochondrial particle (SMP) test and the Microtox® test. The first bioassay makes use of SMPs and is based on the effects of toxicants on reverse electron transport, which is induced by adenosine triphosphate and succinate at the first site level of the respiratory chain. Microtox is a well known test system that uses marine luminescent bacteria and quantifies toxicity by measuring the reduction of luminescence caused by toxic chemicals. Very good agreement was observed between the median effective concentration (EC50) values determined for organotin compounds by means of the two bioassays. Toxicity depended on both the number and kind of organic substituents bound to the tin atom. It followed the order triorganotins &gt; diorganotins ≈ tetraorganotins &gt; monoorganotins. Within each series, butyltin and phenyltin compounds exhibited the highest toxicity. Microtox and SMP EC50 values were successfully correlated with toxicity data for aquatic organisms, demonstrating the usefulness of these bioassays as prescreening or complementary tools for monitoring aquatic toxicity. Moreover, to investigate the suitability of the two assays in providing information on the mechanism of toxic action of organotins, EC50 values were correlated with various physicochemical and structural parameters of the tested compounds. The results obtained showed that these parameters are poor descriptors of organotin toxicity; in particular, the poor correlations found between EC50 values and log Kow could be ascribed to the fact that different modes of action govern the biological activity of mono-, di-, tri-, and tetraorganotin compounds, respectively.
Sequestration of DDT and dieldrin in soil: Disappearance of acute toxicity but not the compounds
Authors: Robertson Boakai K , Alexander Martin 
Published: March 2010

Abstract
House fly (Musca domestica), fruit fly (Drosophila melanogaster), and German cockroach (Blattella germanica) were used to assay the acute toxicity of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and dieldrin aged in sterile soil. Significant reduction in mortality of the insects was observed in DDT- and dieldrin-amended soil samples aged for 30 d, and toxicity decreased further with additional aging. After 270 d, DDT and dieldrin were no longer toxic to house flies, and dieldrin was no longer toxic to fruit flies and cockroaches at 120 d. Nevertheless, 84.7% of the DDT and 92.1% of the dieldrin was recovered from the soil by vigorous extraction after 180 and 270 d, respectively. The results show that toxic chemicals residing in soil become less toxic with time, the extent of decline in bioavailability may differ among different species, and vigorous extraction may grossly overestimate toxicity.
Volatility of chlorinated n-alkanes (C10–C12): Vapor pressures and Henry's law constants
Authors: Drouillard Ken G , Tomy Gregg T , Muir Derek C G , Friesen Ken J 
Published: March 2010

Abstract
Polychlorinated n-decanes, n-undecanes, and n-dodecanes with chlorine numbers of two to six were utilized to assess physicochemical properties of short-chain (C10–C13) chlorinated paraffins. Subcooled-liquid vapor pressures (Ps), determined using the vapor pressure–gas-liquid chromatography correlation technique, ranged from 1.4 × 10−4 to 0.50 Pa at 25°C among the compounds studied. Vapor pressures tended to decrease with increasing carbon chain length and degree of chlorination according to the correlation: log P = −0.353(C No.) — 0.645(0 No.) + 4.462. Henry's law constants (Hs), determined using gas-sparging techniques, ranged from 17.7 to 0.68 PaṁmVmol for terra- and pentachloro congeners at 23°C. The Henry's law constants for 1,10-dichlorodecane and 1,12-dichlorododecane, 499 and 648 Paṁm3/mol respectively at 25°C, were calculated from experimentally determined vapor pressures and water solubilities. Henry's law constants decreased with increasing degree of chlorination.
Bioaccumulation of lipophilic substances in fish early life stages
Authors: Petersen Gitte I , Kristensen Preben 
Published: March 2010

AbstractAccumulation of 14C-labeled polycyclic aromatic hydrocarbons, naphthalene, phenanthrene, pyrene, and benzo(a)pyrene and polychlorinated biphenyl (PCB) congeners PCB 31 and PCB 105 with a log octanol/water partition coefficient (Kow) range from 3.37 to 6.5 was investigated in eggs and larvae of zebra fish (Brachydanio rerio), and in larvae of cod (Gadus morhua), herring (Clupea harengus), and turbot (Scophthalmus maximus). Significant differences in the uptake and elimination rate constants between eggs and larvae of zebra fish were seen. The low rate of uptake and the lower elimination rate of eggs did, however, lead to bioconcentration factors (BCFs) comparable to those for larvae. As biotransformation of xenobiotics in embryonic and larval stages was indicated to be insignificant compared to juvenile/adult stages, body burdens of readily biotransformed chemicals may be higher in fish early life stages. Because weight and lipid content did not differ much between the investigated species, the main reason for the variability in BCFs between marine species (cold water species) and freshwater species (warm water species) was considered to be caused by differences in exposure temperatures that affect the degree of biotransformation. Due to the smaller size of larvae and thus an increased total surface of the membranes per unit fish weight, steady-state conditions were reached at a faster rate in early life stages than in juvenile/adult life stages. The lipid-normalized bioconcentration factors (BCFL) were linearly related to Kow, but BCFL was, in general, higher than Kow, indicating that octanol is not a suitable surrogate for fish lipids. Differences in bioconcentration kinetics between larvae and juvenile/adult life stages are considered to be the main reason for the higher sensitivity, with respect to external effect concentrations, generally obtained for early life stages of fish.
A new technique for determining the sublethal toxicity of pesticides to the vesicular-arbuscular mycorrhizal fungus Glomus intraradices
Authors: Wan Michael T , Rahe James E , Watts Ronald G 
Published: March 2010

Abstract
Sublethal toxicity of selected reference pesticides and solvents to the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus intraradices growing on root inducing transferred DNA (Ri T-DNA)–transformed roots of Daucus carota was determined using a new bioassay technique. Determinations were made on the concentration causing 50% inhibition of growth and development (IC50) to G. intraradices of acetone, methanol, benomyl, chlorothalonil, copper sulfate, dimethoate, glyphosate, and aminomethylphosphonic acid. Effects of these test materials on carrot roots and colonization by G. intraradices were also evaluated. The potential for using G. intraradices as an indicator species and the new technique as a standard test to determine the toxicity of pesticides on VAM fungi for the evaluation of ecosystem impact is discussed.
Accumulation of chromium by a population of mussels (Mytilus edulis (L.)) exposed to leather tannery effluent
Authors: Walsh Andrew R , O'Halloran John 
Published: March 2010

Abstract
The accumulation of chromium was investigated at the tissue and ultrastructural level in mussels (Mytilus edulis (L.)) in an estuary receiving leather tannery effluent and at a reference site. Mussels were also reciprocally transplanted between the estuaries to follow short-term patterns of accumulation and depuration, respectively. The digestive gland was found to accumulate the highest concentrations of chromium in transplanted mussels after 12 months. However, in native mussels (&gt;8 years old), the gill contained the highest concentrations. The general trend in the chromium concentrations of native mussels was: gill &gt; kidney &gt; digestive gland &gt; mantle &gt; adductor muscle. Concentrations of chromium in the gill of mussels close to the tannery outfall were in the range 400 to 1,000 μg/g dry weight, compared to a maximum of 6 μg/g in reference mussels. Seasonally in chromium concentrations was seen at both sites with an early spring maximum evident in reference mussels that could be linked to spawning and an early summer peak in concentrations in the contaminated estuary, possibly as a result of augmented feeding or increased discharges. Relationships between tissue concentrations were also studied and a high correlation occurred between some tissues, for example, digestive gland–kidney and gill–adductor muscle. Depuration was generally slow in mussels transplanted out of the Colligan Estuary, although the digestive gland lost the most chromium. Therefore, it is suggested that two pools of chromium accumulation exist in the contaminated mussels, that is, via the gills (slow) and via the digestive gland (fast). At the cellular level, chromium was found in both particulate (lysosomal) and cytosolic fractions. In the gill, particulate chromium was associated with calcium and phosphorus, whereas chromium was detected in sulfur-dominated granules in the kidney. In the cytosol, binding to a high molecular weight component occurred in the gill, whereas binding in the digestive gland cytosol was dominated by a poorly resolved low molecular weight component. In addition, chromium is apparently detoxified by a separate pathway compared with iron or zinc, as judged by the differential cytosolic and lysosomal affinities of these metals.
Temperature, physiological time, and zinc toxicity in the isopod Porcellio scaber
Authors: Donker Marianne H , Abdel-Lateif Hala M , Khalil Mohamed A , Bayoumi Bayoumi M , Van Straalen Nico M 
Published: March 2010

Abstract
Temperature is an important controlling factor in the metabolism of ectotherms, and it may interact with the toxicity of heavy metals in a variety of ways. In this work, a study on the effect of different zinc concentrations (0.3, 13, 26, and 40 μmol/g dry litter) on growth (body weight) of the isopod Porcellio scaber was conducted using four temperature levels (12, 16, 20, and 24°C). The results demonstrated a significant effect for both zinc and temperature on the growth rate; the interaction between zinc and temperature was also significant. The Arrhenius function was used to describe the temperature–growth rate relationship, from which estimates for the activation energy were derived. A tendency for activation energy to decrease with increasing zinc concentration was observed. Isopods exposed to 13 μmol Zn/g had the highest activation energy and the highest growth rate. To analyze the effect of temperature on the internal body concentration of zinc, the exposure time was transformed into physiological time, calibrated at 15°C, for all experimental groups using the activation energies estimated earlier. The rate of zinc accumulation was derived from the relationship between internal body concentration and physiological exposure time. Differences between isopods cultured at different temperatures could be explained well by the effect of physiological exposure time. The interaction between temperature and zinc toxicity seems to be due not to increased accumulation of zinc at higher temperatures as such but to a physiological interaction with the energy metabolism.
Bioassay technique using nonspecific esterase activities of tetrahymena pyriformis for screening and assessing cytotoxicity of xenobiotics
Authors: Bogaerts Philippe , Senaud Jean , Bohatier Jacques 
Published: March 2010

Abstract
A simple and rapid test for screening and assessing the cytotoxicity of xenobiotics was developed with Tetrahymena pyriformis. The method estimates the activities of nonspecific esterases of a cell by concentrating within it a specific amount of fluorescence associated with fluorescein dye. The 1-h median effective concentration (EC50) values of 10 inorganic and eight organic substances are presented and compared to those of three other bioassays: the conventional T. pyriformis proliferation rate 9-h median inhibitory concentrations, the Microtox® 30-min EC50s, and the Daphnia magna 4-methylumbelliferyl β-D galactoside 1-h EC50s. A highly significant correlation was found between the results obtained with the fluorescein diacetate test and those obtained with the growth inhibition and Microtox tests. This in vivo enzymatic test showed high sensitivity to all compounds tested except Cr6+ and sodium dodecyl sulfate.
Long-term changes in sediment barium inventories associated with drilling-related discharges in the Santa Maria Basin, California, USA
Authors: Phillips Charles , Evans John , Hom Wilson , Clayton John 
Published: March 2010

Abstract
Nine-year (1986–1995) records of barium (Ba) concentrations in surficial, subsurface, and suspended sediments near offshore oil and gas platforms in the Santa Maria Basin, California, USA, were analyzed to evaluate temporal trends related to drilling activities. These trends provide important information on the long-term effects of drilling discharges on geochemical conditions. Drilling during the 1986 through 1989 (phase II) monitoring period resulted in significant changes in Ba concentrations in suspended particles and surficial sediments, whereas the relatively shorter 1993 through 1994 (phase III) drilling operations resulted in only minor increases in Ba concentrations in suspended sediments. Residual excess Ba was present in some sediments within 500 m of the platforms at concentrations up to an order of magnitude above background. These elevated levels probably were associated with cuttings particles deposited near the base of the platforms. Calculated excess Ba in sediments within 500 m of the platforms represented 6 to 11% of the total Ba discharged during the two drilling periods.
Coupled effects of nonlinear, rate-limited sorption and biodegradation on transport of 2,4-dichlorophenoxyacetic acid in soil
Authors: Hu Max Q , Brusseau Mark L. 
Published: March 2010

Abstract
The transport and fate of many contaminants in subsurface systems can be influenced by several coupled processes, such as nonlinear, rate-limited sorption and biodegradation. We investigated the transport in soil of a model organic compound, 2,4-dichlorophenoxyacetic acid (2,4-D), influenced by nonlinear, rate-limited sorption and biodegradation. Miscible displacement and batch sorption experiments were conducted using a wide range of solute concentrations to investigate the impact of concentration-dependent behavior on transport. The sorption isotherm was approximately linear at a low concentration, and nonlinear over the extended range of concentrations. Results from the transport experiments, with the fitted N values approaching 1 at low input concentrations, were consistent with the batch sorption study. Nonlinear sorption significantly influenced the position of the breakthrough curves because of concentration-dependent retardation. However, although both nonlinear and rate-limited sorption influenced the shape of the breakthrough curves, the impact of rate-limited sorption was greater. The effective travel time of 2,4-D transport is influenced by synergistic interactions between sorption and biodegradation. For example, the sequential rightward shift of the breakthrough curves with decreasing input concentration, due to nonlinear sorption of 2,4-D, is enhanced by biodegradation.
Effect of pyrophosphate on the dechlorination of tetrachloroethene by the Fenton reaction
Authors: Wang Xiaojiang , Brusseau Mark L 
Published: March 2010

Abstract
The effectiveness of Fenton's reagent for the remediation of contaminated sandy soils is affected by the precipitation and sorption of Fe species in soil/water systems. We investigated the ability of pyrophosphate to maintain Fe in solution and thus enhance the dechlorination of tetrachloroethene (PCE) by the Fenton reaction. The results of the experiments showed that pyrophosphate could significantly increase the concentrations of Fe in aqueous solutions and enhance the dechlorination of PCE. The dechlorination rate of PCE in the presence of pyrophosphate was found to decrease with time, which was attributed to both the conversion of Fe(II) to Fe(III) and the decrease of aqueous Fe concentration. In comparison to organic chelating agents, pyrophosphate appeared to be more stable and thus catalyzed the dechlorination of PCE for a longer time. The extended dechlorination (&gt;120 h) was attributed to the solubilization of Fe and the stabilization of H2O2 caused by the addition of pyrophosphate.
Evaluating environmental persistence
Authors: Webster Eva , Mackay Don , Wania Frank 
Published: March 2010

Abstract
Environmental persistence is an important consideration when assigning priorities to chemical contaminants. It has been proposed that pass/fail half-life criteria be established for the media of air, water, soil, and sediment. The feasibility of applying such criteria is discussed. It is shown that there are severe problems in estimating these half-lives. Additionally, it is shown that the overall environmental half-life or persistence in a multimedia environment is also a function of the mode of entry of the chemical and its partitioning properties. Examples of potential misclassification are presented. An alternative two-tiered procedure is suggested in which the first tier considers only media half-lives and the second tier considers the overall half-life as deduced by mass-balance models. Furthermore, the overall persistence calculated in the second tier should be given as a distribution rather than a single value. This procedure enables chemicals to be compared, avoids undue reliance on relatively unimportant half-lives, and is regarded as a truer depiction of actual chemical persistence in the environment.
Quantitation of Aroclors using congener-specific results
Authors: Newman John W , Becker Jonathan S , Blondina Gloria , Tjeerdema Ron S 
Published: March 2010

Abstract
As analytical capabilities have increased over the last 30 years, the standard approach applied to the analysis of polychlorinated biphenyls (PCBs) has slowly shifted from technical grade approximation to component-based analyses. This practice, although improving the quality and toxicologic relevance of the resulting data, has limited the historical database as a useful comparative set for current environmental research and is divergent from existing regulatory practices. Aroclor conversion factors have been calculated for each of 14 PCB congeners (International Union for Pure and Applied Chemistry [IUPAC] numbers 18, 28, 31, 99, 118, 128, 138, 149, 153, 180, 194, 195, 201, and 203), allowing quantification of PCB profiles as Aroclors 1248, 1254, and 1260 using measurements of these congeners. The three specified Aroclors are the dominant forms observed in the California marine environment. Speciation is accomplished by comparing characteristic congener ratios in the technical mixtures (31:118 for 1248 and 1254 and 118:203 for 1260) with those found in samples, providing a means for objectively minimizing biases introduced by cochromatographing Aroclor mixtures. The outlined procedure is shown to accurately detect, speciate, and quantify mixtures of multiple Aroclors. Additionally, comparing the predicted and actual concentration of PCB 153 in a sample provides a working index of weathering for these Aroclors.
Mammalian and teleost cell line bioassay and chemically derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent concentrations in lake trout (Salvelinus namaycush) from Lake Superior and Lake Ontario, North America
Authors: Whyte Jeff J , van den Heuvel Mike R , Clemons Janine H , Huestis Susan Y , Servos Mark R , Dixon D George , Bols Niels C 
Published: March 2010

Abstract
For livers of lake trout from three Great Lakes sites, the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent concentrations (TEQs) were determined in four ways. Bioassay-derived (BD) TEQs were measured with rat (H4IIE) and rainbow trout (RTL-W1) cell lines, and chemistry-derived (CD) TEQs were calculated with TCDD equivalency factors (TEFs) derived with H4IIE and RTL-W1. Generally, BD-TEQs and CD-TEQs for individual samples did not differ significantly for either H4IIE or RTL-W1, indicating that all of the AhR-active compounds in a sample were accounted for by the congener analysis and that these compounds acted in an additive fashion in both mammalian and piscine systems. However, contributions of individual chemicals to overall CD-TEQs differed with H4IIE and RTL-W1 TEFs, and for some individual samples, TEQs did depend on the method used. Hepatic TEQs and ethoxyresorufin-O-deethylase (EROD) levels differed significantly between sites. For TEQs, the order was Glenora &gt; Jackfish Bay &gt; Black Bay; for EROD activity, the order was Jackfish Bay &gt; Glenora = Black Bay. No correlation was found between hepatic TEQs and EROD activity, which suggests that the two measurements are evaluating different but related consequences of contaminant exposure.