bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partitioning of copper at concentrations below the marine water quality criteria
Authors: Paulson Anthony J , Gendron James F 
Published: March 2010

Abstract
Partitioning of Cu between the aqueous and particulate phases and among their components was examined in six ambient Puget Sound, Washington State, USA, samples (6–10 nM Cu). Most of the particulate Cu (4–12% of the total Cu) was associated with particulate organic matter, and resulted in distribution coefficients (Kd) ranging between 104,55 and 105,1. For the dissolved phase, the portion of Cu extracted by C18-packed cartridges averaged 44% (+ 11%). Radioactive 64Cu was added to these samples to total stable Cu concentrations (17–33 nM). After 24 h of equilibration, the portion of 64Cu associated with the particulate matter in five of the six samples (Kd between 1047 and 1053) was an average of 70% higher than that of natural Cu in the ambient samples. In contrast, only 19 ± 7% of the 64Cu was extracted by C18-packed cartridges. The partitioning of natural Cu and 64Cu onto particles was not significantly different when the equilibria were based on dissolved Cu passing through the C18 cartridges. Further research is warranted on utilizing the hydrophilic component of the dissolved phase as a parameter on which water quality criteria are based.
Potential of activated carbon to decrease 2,4,6-trinitrotoluene toxicity and accelerate soil decontamination
Authors: Vasilyeva Galina K , Kreslavski Vladimir D , Oh Byung-Taek , Shea Patrick J 
Published: March 2010

AbstractActivated carbon can be used to decrease 2,4,6-trinitrotoluene (TNT) toxicity and promote bioremediation of highly contaminated soil. Adding activated carbon at 0.25, 0.75, and 1.0% (w/w) to Sharpsburg soil contaminated with 500, 1,000, and 2,000 mg TNT/kg decreased concentrations of TNT and its transformation products in soil solution to 5 mg/L or less, resulting in low toxicity to corn plants (Zea mays L.) and soil microorganisms. As much as 50% of the added TNT was rapidly bound to the soil-activated carbon matrix. Simultaneous accumulation of 2,4,6-trinitrobenzaldehyde (TNBAld) indicated that the activated carbon promoted oxidation of TNT. Some of the TNBAld was further oxidized to 1,3,5-trinitrobenzene, followed by reduction to 3,5-dinitroaniline. Reversibly bound TNT was gradually transformed to 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene, and both were bound to the soil-activated carbon matrix. The transformation and binding of TNT to soil were further promoted by incorporating shredded corn plants after growing for 52 d in the activated carbon–amended soil. After 120 d, these amendments reduced extractable TNT and transformation products by 91% in soil containing 2,000 mg TNT/kg, compared to 55% in unamended soil. These results demonstrate the potential use of activated carbon in combination with plants to promote in situ bioremediation of soils highly contaminated with explosives.
Abiotic processes influencing fipronil and desthiofipronil dissipation in California, USA, rice fields
Authors: Ngim Kenley K , Crosby Donald G 
Published: March 2010

Abstract
Fipronil insecticide dissipated in California rice fields, producing half-lives of 10.5 to 125h in water and 44.5 to 533 h in soil, depending on the formulation applied and the resulting differences in water solubility. The major degradation products were desthiofipronil in water and fipronil-sulfide in soil, while the sulfone and amide were less abundant. Fipronil was photolyzed rapidly to desthiofipronil in deionized water in the laboratory (t½ = 7.97–9.42 h) and even faster in the presence of H2O2 (t½ = 0.874–4.51 h). Fipronil was also hydrolyzed to amide in base (t½ = 542 h at pH 9) and volatilized slowly from water (H = 6.60 × 10−6 m3·atm/mol) properties not explaining its rapid field water dissipation. Desthiofipronil was more stable than fipronil to direct photolysis (t½ = 120–149 h), was indirectly photolyzed in the presence of H2O2 (t½ = 0.853–3.76 h), and was nonvolatile from water. The desthiofipronil observed in field water was formed photochemically from fipronil, accumulated due to slower photolysis and lack of volatility from water, but eventually dissipated.
Identification and treatment of a waste stream at a bleached-kraft pulp mill that depresses a sex steroid in the mummichog (Fundulus heteroclitus)
Authors: Dubé Monique G , MacLatchy Deborah L 
Published: March 2010

AbstractChanges to indicators of reproductive performance have been documented in fish exposed to some bleached kraft pulp mill effluents (BKPMEs). However, responses are not consistent across mill types or processes. It is not clear where the sources of the effects are within mills, what the causative compounds are, or what process changes are effective to remove these sources. Our previous studies suggested that condensates were a source of compounds that reduced plasma testosterone in the mummichog (Fundulus heteroclitus). Results also suggested that reverse osmosis (RO) treatment of condensates removed this source. The objective of this study was to use a toxicity identification evaluation approach and expose mummichog to various waste streams in the laboratory to identify the effluent source that depressed plasma testosterone in the mummichog and the effects of RO treatment. In 7- and 21-d exposures, mummichog were exposed to dilutions of RO feed condensate, RO permeate, combined mill effluent (CME), and final effluent. Results confirmed that condensates depressed plasma testosterone in mummichog. Chemical characterization of the condensate indicated that plant phytosterols were likely not the responsible compounds. Results also confirmed that RO treatment removed the potential of the condensates to depress plasma testosterone in mummichog at environmentally relevant concentrations of final mill effluent (1%).
Influence of salinity and eutrophication on bioaccumulation of 99technetium in duckweed
Authors: Hattink Jasper , Wolterbeek Hubert Th , de Goeij Jeroen J M 
Published: March 2010

Abstract
This study concerns the bioaccumulation of the long-lived nuclear waste product 99Tc in duckweed (Lemna minor L.). 99Tc was present as the oxyanion TcO4−, being the main chemical form of technetium in aerobic water systems. In contrast with terrestrial plants, bioaccumulation in duckweed proved to be independent of the nitrate concentration in the medium. However, uptake is controlled by electrostatic effects in the cell wall, which affects the bioaccumulation of 99Tc in duckweed in natural environments. These waters are characterized by a range of salinity and hardness, and this study suggests that this may result in up to a threefold difference in 99Tc accumulation. Because of screening of negative charges in the cell wall, the highest accumulation may be expected in hard, brackish water. This behavior can be described by a general model, which includes electrostatic effects and binding of cations at the cell wall. The model also explains why cationic radionuclides are preferably taken up in soft, fresh water while anionic species are concomitantly taken up in hard, chlorine-rich waters.
Whole blood concentrations of organochlorines as a dose metric for studies of the glaucous gull (Larus hyperboreus)
Authors: Bustnes Jan O , Skaare Janneche U , Erikstad Kjell E , Bakken Vidar , Mehlum Fritjof 
Published: March 2010

AbstractIn order to examine if whole blood concentrations of organochlorines (OCs) is anappropriate dosimetric parameter for use in ecotoxicological studies of free-living birds, a number of incubating glaucous gulls (Larus hyperboreus) were repeatedly sampled within and between subsequent breeding seasons. The wet weight concentrations of selected OCs, differing in persistence and fat solubility, were compared and it was assessed to what extent present concentrations could be predicted from concentrations previously measured in the individuals. There were only a few significant differences in the blood concentrations of the selected OCs within and between seasons. The most persistent compound, polychlorinated biphenyl (PCB)-153, showed a low interindividual variability, and between seasons, 70% of the variance could be explained by the level in the previous year, while changes in body condition and blood lipid percentage were of less importance. For PCB-101, the predictability of the present blood concentration from the previous concentration was lower than for PCB-153, and changes in body condition and blood lipid percentage explained a higher proportion of the variance. The present level of α-hexachlorocyclohexane (HCH) could not be predicted from the previous level. Sex did not explain any significant proportion of the variance in OC concentrations when previous level and changes in body mass and blood lipid were included in the statistical models. Thus, for the most persistent OCs, concentration in the blood of incubating glaucous gulls is representative for the interindividual differences over time and whole blood concentrations of OCs appear adequate as a dose metric in ecotoxicological studies.
Influences of metal concentration in phytoplankton and seawater on metal assimilation and elimination in marine copepods
Authors: Xu Yan , Wang Wen-Xiong , Hsieh Dennis P H 
Published: March 2010

Abstract
Radiotracer experiments were conducted to examine the influence of the concentration of Cd, Se, and Zn in ingested phytoplankton (dinoflagellate Prorocentrum minimum and diatom Thalassiosira weissflogii) and in ambient seawater on metal assimilation and elimination efficiencies of three marine copepods, Acartia spinicauda, Paracalanus aculeatus, and Calanus sinicus. The assimilation efficiencies (AEs) decreased by 1.7 to 2.0 times, 1.4 to 4.1 times, and 1.3 to 2.2 times in the copepods with an increase in metal concentration in ingested algae by 16 to 84 times, 14 times, and 45 to 153 times, for Cd, Se, and Zn, respectively. However, the physiologic turnover rate constant was relatively independent of the metal concentration in copepods. No evidence was found of any interaction between Cd and Zn in their assimilation by copepods. Assimilation efficiencies of Cd were higher in copepods feeding on the dinoflagellate P. minimum, whereas the AEs of Zn were higher in copepods feeding on the diatom T. weissflogii. Differences in metal distribution in algal cytoplasm at different ambient metal concentrations may be partially responsible for the observed influence of metal concentration in algal cells on metal assimilation in copepods. However, metal desorption within the gut of the copepod may have little influence on metal assimilation, as a result of the short gut residence time of food particles and the neutral gut pH. Our study also indicated that the ingestion rate of copepods was reduced by a higher concentration of Cd and Se, but was not affected by Zn concentration in the food particles. Consequently, partial regulation of metal trophic transfer in response to increasing metal contamination may be achieved by a change in metal assimilation efficiency and the ingestion activity of the copepod, but not by changes in metal turnover rates from the animals.
Effects of di(2-ethylhexyl) phthalate and dibutyl phthalate on the collembolan Folsomia fimetaria
Authors: Jensen John , van Langevelde Judith , Pritzl Gunnar , Krogh Paul Henning 
Published: March 2010

Abstract
Lethal and sublethal effects of di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) on adult individuals of the collembolan Folsomia fimetaria were investigated in the laboratory by the use of small microcosms. Effects of DEHP and DBP were also tested on newly hatched collembolans in a multidish system. The endpoints were juvenile mortality, growth, and development. When exposed to DEHP, adults and juveniles were unaffected at all test concentrations, that is, up to 5,000 mg/kg. However, DBP caused increased adult mortality at 250 mg/kg and juvenile mortality at 25 mg/kg. For DBP, adult reproduction was a more sensitive endpoint than was survival, with an EC10 and EC50 of 14 and 68 mg/kg, respectively. Juvenile molting frequency seems to be a sensitive parameter, because number of cuticles produced by young springtails was reduced at 1 mg/kg. Toxicity was reduced when soil spiked with DBP was stored at 20°C for a period of up to 28 d before adding the animals. Reduction in toxicity of DBP may be due a combination of degradation, evaporation, and adsorption of DBP to soil material. This was confirmed by chemical analyses, which showed a rapid initial disappearance followed by a much slower disappearance. Our results lead to the overall conclusion that significant adverse effects of phthalates on collembolans are not likely to occur as a result of normal sewage sludge application.
Amendment of sediments with a carbonaceous resin reduces bioavailability of polycyclic aromatic hydrocarbons
Authors: West Corlis W , Kosian Patricia A , Mount David R , Makynen Elizabeth A , Pasha Mumtaz S , Sibley Paul K , Ankley Gerald T 
Published: March 2010

AbstractWe evaluated the effectiveness of Amersorbb®, a carbonaceous resin, in reducing bioavailability of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments collected from the field. In laboratory studies, sediment pore-water concentrations of eight unsubstituted PAHs were significantly decreased after resin addition. Reduced PAH concentrations in oligochaete tissues from a laboratory bioaccumulation test, along with increased survival/reproduction and reduced photo-enhanced toxicity and sediment avoidance, also resulted from sediment treatment with Ambersorb. Resin amendment also decreased pore-water PAH concentrations in field deployed sediments but did not improve benthic invertebrate colonization. Prediction of partitioning of PAHs between solid and aqueous phases in the test sediments was complicated by the presence of coal and soot. However, accurate predictions of bioavailability were achieved based on pore-water chemistry. Overall, these studies show that the addition of high affinity sorbents effectively reduces pore-water PAH concentrations and bioavailability and suggests that sorbent addition may serve as an option for in situ remediation of some contaminated sediments.
Monitoring of endocrine disruptors in surface waters by the yeast recombinant assay
Authors: García-Reyero Natàlia , Grau Eulàlia , Castillo Montserrat , De Alda Maria José López , Barceló Damià , Piña Benjamin 
Published: March 2010

Abstract
Endocrine disruptors exert physiological effects at very low concentrations. Surface waters present often a mixture of high concentrations of low-potency disruptors and low amounts of very powerful ones, making their chemical analysis complicated and expensive. We developed a recombinant yeast assay (RYA) for estrogenic compounds using 96-well microtiter plates. This assay is based on three yeast strains, transformed with self-propagating plasmids. One strain contains an expression plasmid for the human estrogen hormone recéptor and an appropriate reporter; it detects estrogenic and antiestrogenic activities. The two other yeast strains, one expressing the human progesterone receptor and a second based on the yeast activator Gal4p, served to analyze the nature of antiestrogenic activities. We applied this technique to water samples from two tributaries of the Llobregat river (NE Spain) as well as from four sewage treatment plants discharging on them. Our results indicate that the efficiency of sewage treatment plants for eliminating estrogenic compounds varied notably, being in at least one case completely inefficient. We also observed a prevalence of an inhibitory activity all through the two rivers; this inhibition was hormone specific. These results were consistent to previously obtained chemical analyses of the same samples, although chemical and in vivo analyses showed rather different levels of sensitivity for some compounds. Our findings demonstrate the utility of the yeast recombinant assay for analyzing complex natural samples; at the same time, they stress the necessity of a panel of different yeast systems to adequately describe endocrine-disruptor activities.
Indirect effects of zinc on soil microbes via a keystone enchytraeid species
Authors: Salminen Janne , Anh Bui Tan , van Gestel Cornelis A M 
Published: March 2010

Abstract
Effects of Zn pollution on a keystone species of forest soils, the enchytraeid Cognettia sphagnetorum, and its consequent indirect effects on microbial biomass and activity were studied in a microcosm experiment using experimentally contaminated humic soil. Microbial growth and decomposition were enhanced in the presence of C. sphagnetorum. At high Zn concentrations (&lt;2,393 mg/kg dry soil), populations of C. sphagnetorum weht extinct, resulting in negative indirect effects on microbial activity as measured by soil respiration. Results indicate that pollution may affect species interactions in a soil food web and indirectly affect ecosystem processes such as decomposition rate. Effects of pollution on keystone organisms may radically alter soil ecosystem functioning and should be taken into account during risk-assessment procedures.
Bioaccumulation of polycyclic aromatic compounds: 2. Modeling bioaccumulation in marine organisms chronically exposed to dispersed oil
Authors: Baussant Thierry , Sanni Steinar , Skadsheim Arnfinn , Jonsson Grete , Børseth Jan Fredrik , Gaudebert Bertrand 
Published: March 2010

AbstractWithin the frame of a large environmental study, we report on a research program that investigated the potential for bioaccumulation and subsequent effect responses in several marine organisms exposed to chronic levels of dispersed crude oil. Body burden can be estimated from kinetic parameters (rate constants for uptake and elimination), and appropriate body burden-effect relationships may improve assessments of environmental risks or the potential for such outcomes following chronic discharges at sea. We conducted a series of experiments in a flow-through system to describe the bioaccumulation kinetics of polycyclic aromatic hydrocarbons (PAH) at low concentrations of dispersed crude oils. Mussels (Mytilus edulis) and juvenile turbot (Scophthalmus maximus) were exposed for periods ranging from 8 to 21 d. Postexposure, the organisms were kept for a period of 9 to 10 d in running seawater to study elimination processes. Rate constants of uptake (k1) and elimination (k2) of the PAHs during and following exposure were calculated using a first-order kinetic model that assumed a decrease of the substances in the environment over time. The estimated bioconcentration factor was calculated from the ratio of k1/k2. The kinetic parameters of two-, three-, and four-ring PAHs in mussel and fish are compared with estimates based on hydrophobicity alone, expressed by the octanol-water partition coefficient, Kow (partitioning theory). A combination of reduced bioavailability of PAHs from oil droplets and degradation processes of PAHs in body tissues seems to explain discrepancies between kinetic rates based on Kow and actual kinetic rates measured in fish. Mussels showed a pattern more in compliance with the partitioning theory.
Effects of the synthetic estrogen 17α-ethinylestradiol on the life-cycle of the fathead minnow (Pimephales promelas)
Authors: Länge Reinhard , Hutchinson Thomas H , Croudace Charlotte P , Siegmund Fred , Schweinfurth Hermann , Hampe Peter , Panter Grace H , Sumpter John P 
Published: March 2010

Abstract
A fish full life-cycle (FFLC) study was conducted for 17α-ethinylestradiol (EE2) using the fathead minnow, Pimephales promelas. Newly fertilized embryos (&lt;24 h old) were exposed to five concentrations of EE2 (0.2, 1.0, 4.0, 16, and 64 ng/L nominal) in continuous flow-through conditions for 305 d at 25 ± 1°C. Exposure concentrations were verified by 14C-EE2 radiochemistry, supported by radioimmunoassay, and mean measured values were ≥70% of nominal. For the F0 adult phase until 301 d posthatch, the no-observed-effect concentrations (NOECs) for growth, survival, and reproduction (as egg production) were all ≥ 1.0 ng/L. The NOEC values for F1 embryo hatching success and larval survival (at 28 d posthatch) were both ≥ 1.0 ng/L. While statistically detectable changes in F1 growth were evident at 0.2 ng/L, these were not considered to be biologically significant when compared with historical control data. Male fish exposed to EE2 at 4.0 ng/L failed to develop normal secondary sexual characteristics; on the other hand, assumed females exposed to this level of EE2 were able to breed when paired with males that had not been exposed to EE2. Histology of F0 control, 0.2-, and 1-ng/L exposed fish at 56 d posthatch indicated an approximate female-to-male (F:M) sex ratio of 50:50 (with no ovatestes observed in the control), while fish exposed to EE2 at 4.0 ng/L for 56 d posthatch had a F: M sex ratio of 84:5 (with ovatestes in 11% of fish). After 172 d posthatch, no testicular tissue was observed in any fish exposed to EE2 at 4.0 ng/L. At the same time point, plasma vitellogenin levels were significantly higher in fish exposed to EE2 at 16 ng/L. A lack of sexual differentiation occurred in males at concentrations ≥4.0 ng/L. Taking into account these data, the overall no-observed-adverse-effect concentration was considered to be 1.0 ng/L.
Effects ofAnabaena spiroides(cyanobacteria) aqueous extracts on the acetylcholinesterase activity of aquatic species
Authors: Monserrat José María , Yunes Joào Sarkis , Bianchini Adalto 
Published: March 2010

AbstractThe effects of aqueous extracts from a cyanobacteria species, Anabaena spiroides, on fish (Odontesthes argentinensis), crab (Callinectes sapidus), and purified eel acetylcholinesterase (AChE) activity were studied. In vitro concentrations of A. spiroides aqueous extract that inhibited 50% of enzyme activity (IC50) were 23.0, 17.2, and 45.0 mg/L of lyophilized cyanobacteria for eel, fish, and crab AChE, respectively. Eel AChE inhibition follows pseudo-first-order kinetics, the same expected for organophosphorus pesticides. Inhibition of purified eel AChE using mixtures of bioxidized malathion and aqueous extract of A. spiroides showed a competitive feature (p &lt; 0.05), suggesting that the toxin(s) could be structurally similar to an organophosphorus pesticide and that toxins present in the aqueous extract inhibit the active site of the enzyme. The inhibition recovery assays using 2-PAM (0.3 mM) showed that (1) bioxidized malathion inhibited 27.0 ± 1.1% of crab and 36.5 ± 0.1% of eel AChE activities; (2) with bioxidized malathion + 2-PAM the registered inhibition was 13.2 ± 2.1% and 3.7 ± 0.5% in crab and eel AChE, respectively; (3) the aqueous extract from A. spiroides inhibited 17.4 ± 2.2% and 59.9 ± 0.5% of crab and eel AChE activity, respectively; and (4) aqueous extract + 2-PAM inhibited 22.3 ± 2.6 and 61.5 ± 0.2% of crab and eel AChEs. The absence of enzyme activity recovery after 2-PAM exposure could imply that the enzyme aging process was extremely quick.