bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioaccumulation profiles of polychlorinated biphenyl congeners and organochlorine pesticides in Ganges river dolphins
Authors: Senthilkumar Kurunthachalam , Kannan Kurunthachalam , Sinha Ravindra K , Tanabe Shinsuke , Giesy John P 
Published: March 2010

AbstractIsomer-specific concentrations of polychlorinated biphenyls (PCBs) including non-, mono-, and di-ortho-substituted congeners, DDT and its metabolites, hexachlorocyclohexane (HCH) isomers, chlordane compounds, and hexachlorobenzene (HCB) were determined in river dolphin blubber and prey fishes collected during 1993 through 1996 from the River Ganges in India. Concentrations of organochlorines were also measured in the milk and liver of dolphins, benthic invertebrates, and sediments. The DDTs and PCBs were the predominant compounds found in dolphin tissues and fish that comprise the diet of dolphins. Concentrations of DDTs and PCBs in the blubber of dolphins were in the range of 30 to 120 and 1.5 to 25 μg/g, lipid weight, respectively. Pentaand hexachlorobiphenyls collectively accounted for 68 to 80% of the total PCB concentrations in river dolphins. Hexachlorobiphenyl congener 138 (2,2′,3,4,4′,5′-) was the most abundant in dolphin blubber and prey fishes. The isomer/congener pattern of PCBs and organochlorine pesticides suggested that there is less metabolism due to cytochrome P450 enzymes in Ganges river dolphins than in marine or terrestrial mammals. The mean 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) estimated in river dolphin blubber was greater than those that can cause adverse effects in mink. Comparison of organochlorine concentrations in river dolphins with those of the values reported for samples analyzed during 1988 through 1992 suggested that the contamination by these compounds has increased in the River Ganges.
Impact of grain scale heterogeneity on slow sorption kinetics
Authors: Kleineidam Sybille , Rügner Hermann , Grathwohl Peter 
Published: March 2010

Abstract
Groundwater contamination by dissolved organic compounds frequently occurs in valley aquifers that consist of highly heterogeneous sand and gravel sediments. Remediation and risk assessment (e.g. reactive transport modeling) requires detailed information on the sorption/desorption kinetics in such aquifer materials. In this paper we present data on slow sorption kinetics of phenanthrene and the composition of several aquifer materials that are typical for southern Germany and Switzerland. The heterogeneity of the aquifer material is described in terms of the physical and chemical properties (e.g., grain size, organic carbon content, intraparticle porosity, sorption parameters, and rate constants for intraparticle diffusion) of the sediment constituents (lithocomponents). Phenanthrene sorptive uptake in a heterogeneous bulk sample can be predicted using a numerical model only if the composition and geochemical heterogeneity (different sorptivities and porosities of the lithocomponents) are considered. It could be shown that even within a narrow grain size fraction, the geochemical heterogeneity has to be incorporated for the prediction of long-term sorptive uptake or release of organic contaminants.
Tissue carboxylesterase activity of rainbow trout
Authors: Barron Mace G , Charron Kem A , Stott William T , Duvall Stephanie E 
Published: March 2010

AbstractThe activity of carboxylesterase (CaE), a class of nonspecific serine hydrolases, was evaluated in vitro in tissues and microsomes of rainbow trout and compared to esterase activity in rats, other fish species, and embryo to adult life stages of trout. Trout gill and liver microsomes exhibited substantial CaE activity and limited variation over the range of 2 to 40°C, with a temperature optimum of approximately 22°C. Trout sera and rat liver microsomes exhibited a temperature optimum of approximately 35 to 40°C. The CaE of trout liver (maximum reaction rate [Vmax] = 672 nmol/min/mg microsomal protein) was four times less than in rats. Apparent Michaelis constant (Km) values ranged from 28 (trout liver) to 214 (trout sera) μM. Values of Vmax/Km suggested that in vivo CaE activity of trout liver would be about three times higher than serum, 135 times higher than gill, and three times lower than rat liver. The CaE activity in whole rainbow trout homogenates significantly increased 300% per gram of tissue to 1,200% per milligram of protein between the yolk-sac and juvenile stages. The CaE activity of whole fish homogenates was not significantly different in juvenile rainbow trout, channel catfish, fathead minnows, and bluegill. The results demonstrate that rainbow trout had high esterase activity over a broad range of temperatures, that CaE activity significantly increased between the yolk-sac and juvenile life stages, and that variation between the CaE activity in trout and three other families of freshwater fish was limited. The CaE activity in fish is expected to substantially influence the accumulation and toxicity of pesticides and other esters entering the aquatic environment.
Toxicity of aryl- and benzylhalides to Daphnia magna and classification of their mode of action based on quantitative structure–activity relationship
Authors: Marchini Silvia , Passerini Laura , Hoglund Marilynn D , Pino Anna , Nendza Monika 
Published: March 2010

Abstract
The acute toxicity of aryl- and benzylhalides to Daphnia magna was investigated to test the validity of existing classification schemes for chemicals by mode of action, mainly based on fish studies, and the applicability of predictive quantitative structure–activity relationship (QSAR) models. Halobenzenes and halotoluenes are generally agreed to be unambiguous baseline toxicants (class I) with the major exception of the benzylic structures, which are reactive in fish tests (class III). Eighty-nine percent of the arylhalides tested in this study match a log Pow-dependent QSAR, including fluorinated, chlorinated, brominated, and iodinated derivatives, thereby confirming the validity of the baseline models also for variously halogenated compounds (other than only-chloro compounds). The toxicities of the benzylhalides relative to baseline QSARs clearly indicate that these compounds belong to two classes by mode of action, i.e., they either act as narcotic toxicants (class I) or reveal excess toxicity due to unspecific reactivity (class III). On some occasions, the assignment to the two classes in D. magna deviates from the structural rules derived from fish, i.e., iodinated compounds as well as α,α-Cl2-toluenes lack reactive excess toxicity but behave as nonpolar nonspecific toxicants. The QSARs derived during this study reveal lower slopes and higher intercepts than typical baseline models and, together with the analysis of mixture toxicity studies, behavioral studies, and critical body burden, advocate the hypothesis that there are several different ways to produce baseline toxicity. Most halobenzenes and halotoluenes are actually baseline chemicals with some extra reactivity and as such form a subgroup, whose limits still have to be defined. Different primary sites of action could explain why the chemicals are discriminated by different classification systems, but still they must have some rate-limiting interaction in common (e.g., lipid diffusion) as they fit the same log Pow-dependent baseline QSAR.
Major ion toxicity in effluents: A review with permitting recommendations
Authors: Goodfellow William L , Ausley Lawrence W , Burton Dennis T , Denton Debra L , Dorn Philip B , Grothe Donald R , Heber Margarete A , Norberg-King Teresa J , Rodgers John H 
Published: March 2010

Abstract
Effluent toxicity testing methods have been well defined, but for the most part, these methods do not attempt to segregate the effects of active ionic concentrations and ion imbalances upon test and species performances. The role of various total dissolved solids in effluents on regulatory compliance has emerged during the last few years and has caused confusion in technical assessment and in permitting and compliance issues. This paper assesses the issue of ionic strength and ion imbalance, provides a brief summary of applicable data, presents several case studies demonstrating successful tools to address toxicity resulting from salinity and ion imbalance, and provides recommendations for regulatory and compliance options to manage discharges with salinity/ion imbalance issues. Effluent toxicity resulting from inorganic ion imbalance and the ion concentration of the effluent is pervasive in permitted discharge from many industrial process and municipal discharges where process streams are concentrated, adjusted, or modified. This paper discusses procedures that use weight-of-evidence approaches to identify ion imbalance toxicity, including direct measurement, predictive toxicity models for freshwater, exchange resins, mock effluents, and ion imbalance toxicity with tolerant/susceptible text species. Cost-effective waste treatment control options for a facility whose effluent is toxic because of total dissolved solids (TDS) or because of specific ion(s) are scarce at best. Depending on the discharge situation, TDS toxicity may not be viewed with the same level of concern as other, more traditional, toxicants. These discharge situations often do not require the conservative safety factors required by other toxicants. Selection of the alternative regulatory solutions discussed in this paper may be beneficial, especially because they do not require potentially expensive or high-energy–using treatment options that may be ineffective control options. The information presented is intended to provide a better understanding of the role of ion imbalance in aquatic toxicity testing and to provide various recommendations that should be considered in addressing these issues.
Toxicity of glyphosate and triclopyr using the frog embryo teratogenesis assay—Xenopus
Authors: Perkins Peggy J , Boermans Herman J , Stephenson Gerald R 
Published: March 2010

Abstract
The effects of glyphosate ([N-phosphonomethyl]glycine) and triclopyr ([[3,5,6-trichloro-2-pyridinyl]oxy]acetic acid) on the embryonic development of Xenopus laevis were evaluated using Frog Embryo Teratogenesis Assay—Xenopus (FETAX). Rodeo®, the isopropylamine (ipa) salt of glyphosate formulated without a surfactant was found to be the least toxic, with a LC5 and LC50 of 3,779 and 5,407 mg acid equivalent (AE)/L, respectively. The LC5 and LC50 of Roundup®, the ipa salt of glyphosate formulated with a surfactant, was 6.4 and 9.4 mg AE/L, respectively. The surfactant component of Roundup, polyoxyethyleneamine (POEA), had a LC5 and LC50 of 2.2 and 2.7 mg/L, respectively. Garlon® 3A, the triethylamine salt of triclopyr, had a LC5 and LC50 of 119 and 162.5 mg AE/L, respectively. The LC5 and LC50 of Garlon 4®, the butoxyethyl ester of triclopyr, was 6.7 and 9.3 mg AE/L, respectively. Considering a theoretical worst case scenario when the highest rates recommended for glyphosate (12 L of Roundup/ha) or triclopyr (8 L of Garlon/ha) are applied to water 15 cm in depth, the expected environmental concentrations calculated on the basis of AE would be 2.8 and 2.6 mg AE/L, respectively. The margins of safety (LC5/expected environmental concentrations) for frog embryos exposed to these concentrations would be approximately 2, 2, 47, and 1,312 for Roundup, Garlon 4, Garlon 3A, and Rodeo, respectively.
Metal body burden and biological sensors as ecological indicators
Authors: Birge Wesley J. , Price David J , Shaw Joseph R , Spromberg Julann A , Wigginton Andrew J , Hogstrand Christer 
Published: March 2010

Abstract
Metal body burden (BB) was analyzed in three groups of organisms evaluated as sentinel monitors of metal exposure. The study site was a lotic system of moderate gradient that received effluent outfalls from an uranium enrichment plant. Metal BBs (e.g., Ag, Cd, Cr, Cu) increased in the order Cheumatopsyche spp. (caddisfly), Campostoma anomalum (central stoneroller minnow), and Stenonema spp. (mayfly). This was consistent with their classifications as metal-tolerant, moderately tolerant, and sensitive taxa, respectively. The Ag, Cd, and Cu BBs in stoneroller minnows from upstream, effluent-receiving, and downstream stations correlated strongly with macroinvertebrate bioassessment (BA) scores (r ≤ —0.95), numbers of taxa (r = —0.95), and the Ephemeroptera, Plecoptera, Trichoptera indices (r = —0.82 to —0.94). Proportional differences in metal BBs in the minnow were used to derive metal multipliers that were applied to total recoverable metal concentrations to calculate bioavailable metal. The bioavailable metal fractions correlated with BA scores and numbers of taxa (e.g., Ag, r ≤ —0.97; Cu, r = —0.95). When five metals (i.e., Ag, Cd, Cu, Cr, Pb) were included in an additive model, results also correlated with BA scores (r = —0.93) and numbers of taxa (r = —0.86). Metal BB in minnows was a strong indicator of ecological impact and provided a means of determining bioavailable metals. Also, we describe the development of the metal biosensor, which incorporates a reconstructed fish gill epithelium, the primary target of metal exposure. This in vitro biosensor should directly quantify bioreactive metals that cross the epithelium and react with a genetically engineered intracellular detector. This biosensor complements biotic ligand models based on surface binding of metals to gill epithelia.
A comparison of metal-induced lethality and behavioral responses in the nematode Caenorhabditis elegans
Authors: Dhawan Ritu , Dusenbery David B , Williams Phillip L 
Published: March 2010

Abstract
Behavioral changes are believed to be a sensitive indicator of toxicant exposure but can be very difficult to quantify. Using the free-living soil nematode Caenorhabditis elegans, a computer tracking system was used that measures several behavioral parameters for approximately 100 subjects on a real-time basis. Toxicant exposures can be performed in soil, on agar plates, or in aquatic media. Following the exposure period, the worms are transferred to a thin-layered agar slab for viewing in dark-field illumination by a video camera interfaced directly to a computer. Information can be obtained on a number of behavioral parameters including number of subjects moving, their individual rates of locomotion, and the frequency of change in direction. Exposure to five metals (Pb, Cu, Cd, Al, and Zn) were tested in this study to evaluate behavioral changes in the worm. The nematodes were exposed for 24 h to concentrations of an individual metal in aquatic medium representing the interstitial pore water within the soil. Under identical conditions, concurrent LC50 and BC50 (concentration at which movement is reduced by 50% compared with controls) values were determined for each metal tested. The results from computer tracking revealed significant changes in rate of locomotion at concentrations of less than 10% of the respective LC50 value.
Gender benders at the beach: Endocrine disruption in marine and estuarine organisms
Authors: Oberdörster Eva , Cheek Ann Oliver 
Published: March 2010

AbstractSeveral consensus definitions of the term endocrine disruptor have appeared recently, but all definitions include the important, though frequently implicit, stipulation that the animal is not distressed or in obvious discomfort. Instead, a superficially healthy animal is experiencing alterations in hormone synthesis, transport, receptor interaction, metabolism, excretion, or feedback regulation. In addition, hormone disruption may occur during sex differentiation, and its effects may not be manifested until after sexual maturation. Many cases of chemically induced reproductive impairment have been reported for both freshwater and marine species. However, reproductive impairment may not necessarily result from hormone disruption and should be considered suggestive, but not conclusive, evidence of endocrine disruption. A suite of in vivo and in vitro assays will more adequately assess whether a compound is truly endocrine disrupting. This review will cover basic endocrinology of marine and estuarine invertebrates and vertebrates, methods for detecting endocrine disruption, and examples of endocrine disruption in various species.
Phototactic behavior of Daphnia and the continuous monitoring of water quality: Interference of fish kairomones and food quality
Authors: Kieu Nhan Dang , Michels Erik , De Meester Luc 
Published: March 2010

Abstract
We carried out a laboratory study to evaluate the sensitivity of phototactic behavior of Daphnia magna to sublethal concentrations of pentachlorophenol (PCP) and copper. More specifically, we determined whether the sensitivity of a D. magna clone to those pollutants is influenced by food quality and the presence of fish kairomones. Test animals were fed either unicellular green algae (Scenedesmus acutus) or fresh baker's yeast (Saccharomyces cerevisiae) and were cultured in the presence or absence of fish kairomones. Four concentrations of PCP (0.4, 0.8, 1.2, and 1.6 mg/L PCP) and one concentration of copper (0.02 mg/L Cu2+) in International Standards Organisation (ISO, Geneva, Switzerland) standard medium were applied in the experiments. Animals were exposed for 3 h to the pollutants prior to the experiments. In the absence of fish kairomones, a strong negative relationship between the phototactic index and nominal sublethal concentrations of PCP was found in animals fed either algae or yeast. The sensitivity of the Daphnia clone to sublethal concentrations of PCP was, however, less clear cut in animals fed yeast than in animals fed algae. The detection limit was 0.4 mg/L PCP with algae as food but was as high as 1.2 mg/L PCP when yeast was used as food. The ability to detect sublethal concentrations of copper and PCP using phototactic behavior was lost when the clones were cultured in the presence of fish kairomones. At a concentration of 0.02 mg/L Cu2+ and in the absence of fish kairomones, the D. magna clone tested became significantly less positively phototactic than in the control treatment regardless of the quality of the food used to culture the test animals. These results suggest that assays using the phototactic behavior of Daphnia to monitor water quality should use genetically stable (clonal) material, positively phototactic, and insensitive to the presence of fish kairomones.
Class III metallothioneins in response to cadmium toxicity in the marine microalga Tetraselmis suecica (Kylin) Butch
Authors: Pérez-Rama Mónica , López Concepción Herrero , Alonso Julio Abalde , Vaamonde Enrique Torres 
Published: March 2010

Abstract
Microalgae are one of the most important organisms in our ecosystems being seriously affected by metal pollution. However, the microalgae Tetraselmis suecica (Kylin) Butch is tolerant to cadmium; the concentration of this metal that reduces the population growth to 50% of the control growth level is 5.8 mg/L after 96 h of exposure. In this study, class III metallothioneins were investigated for their involvement as a possible tolerance mechanism in this microalga when exposed to cadmium. A set of these molecules was purified from these microalgal cells after exposure to the metal. These polypeptides were analyzed by capillary zone electrophoresis, which is a technique that allows the length of the metallothioneins synthesized by this microalga to be known. The T. suecica cells were able to synthesize class III metallothioneins of three to six subunits of (γ-Glu-Cys). The most abundant polypeptide possessed four subunits, and (γ-Glu-Cys)6-Gly was the largest polypeptide synthesized by this microalga and detected by this technique. Tolerance to cadmium as a function of increasing polypeptide length is also discussed.
Ultimate biodegradation of alkylphenol ethoxylate surfactants and their biodegradation intermediates
Authors: Staples Charles A , Naylor Carter G , Williams James B , Gledhill William E 
Published: March 2010

Abstract
The ultimate biodegradation of the commercial products nonylphenol ethoxylates (NPE9), octylphenol ethoxylates (OPE9), and their biodegradation intermediates, NPE1.5, OPE1.5, NP, and OP, was measured using conventional methods. The extent of biodegradation was also determined by gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC) analysis of metabolites and measurement of dissolved organic carbon. Optimized pseudo–first order degradation rate constants and half-lives were calculated from these data and from previously published data, using Larson's equation for surfactant degradation kinetics. Ultimate aerobic biodegradation of alkylphenol ethoxylates and their biodegradation intermediates has now been examined using acclimated wastewater treatment plant sludge as the microbial seed, household wastewater treatment systems, and unacclimated fresh water, seawater, and soil. Ultimate biodegradation half-lives ranged from about one to four weeks and provide definitive evidence for the extensive biodegradability of alkyphenol ethoxylates (APE) surfactants and their metabolites and their lack of persistence in the environment.
Use ofUlva lactucato identify ammonia toxicity in marine and estuarine sediments
Authors: Pelletier Marguerite C , Ho Kay T , Cantwell Mark , Kuhn-Hines Anne , Jayaraman Saro , Burgess Robert M 
Published: March 2010

AbstractToxicity identification evaluation (TIE) methods are being developed for use with whole sediments. Although a phase I TIE method has been developed to characterize ammonia toxicity in aqueous samples using the marine macroalga Ulva lactuca, the relationship between amphipod and mysid mortality and uptake by U. lactuca of bedded sediment ammonia had not been explored. Additionally, it was not known how interactions in whole sediments between metal and organic contaminants with U. lactuca and ammonia would affect TIE interpretation. The current study showed that ammonia toxicity to amphipods and mysids was reduced significantly in marine sediments in the presence of U. lactuca. The alga slightly affected metal concentrations but did not alter the concentration of organic contaminants in either overlying or interstitial waters. Conversely, ammonia uptake by U. lactuca was not affected by the presence of metal or organic contaminants in the sediments. When used with other TIE manipulations, U. lactuca can be utilized in a whole-sediment, phase I TIE to remove toxicity due to ammonia.
Biomimetic solid-phase microextraction to predict body residues and toxicity of chemicals that act by narcosis
Authors: Leslie Heather A. , Oosthoek Annelies J. P. , Busser Frans J. M. , Kraak Michiel H. S. , Hermens Joop L. M. 
Published: March 2010

AbstractA biomimetic extraction technique using solid-phase microextraction (SPME) fibers has been developed for the risk assessment of contaminants with a narcotic mode of action. Our goal is to apply this technique in the future for the prediction of total baseline toxicity of environmental water and effluent samples. Validation of this method requires establishing the relationship between contaminant accumulation and toxicity in biota and accumulation in the surrogate solid phase (the SPME fiber coating). For this purpose, we determined the median lethal concentration (LC50) values for Chironomus riparius midge larvae exposed to two halogenated aromatic compounds separately and measured body residues in the exposed larvae. Solid-phase microextraction fibers with an 85-μm polyacrylate (PA) coating served as the surrogate hydrophobic phase, mimicking the uptake of the compounds by midge larvae. The toxicant concentrations in SPME fibers measured directly by gas chromatography/mass spectrometry (GCMS) or calculated from the SPME fiber—water partition coefficient, KSPME, were related to the toxicant concentrations found in midge larvae. Our results demonstrated that the biomimetic SPME method enables the estimation of body residues in biota and prediction of the degree of baseline toxicity of a water medium.