bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid toxicity assessment of sediments from estuarine ecosystems: A new tandem in vitro testing approach
Authors: Johnson B Thomas , Long Edward R 
Published: March 2010

Abstract
Microtox® and Mutatox® were used to evaluate the acute toxicity and genotoxicity, respectively, of organic sediment extracts from Pensacola Bay and St. Andrew Bay, two estuaries that cover about 273 and 127 km2, respectively, along the Gulf coast of Florida, USA. The sensitivity and selectivity of these two bioluminescent toxicity assays were demonstrated in validation studies with over 50 pesticides, genotoxins, and industrial pollutants, both as single compounds and in complex mixtures. The 50% effective concentration (EC50) values of insecticides, petroleum products, and polychlorinated biphenyls determined by Microtox all tended to group around the mean EC50 value of 1.2 (0.8) mg/L. The polycyclic aromatic hydrocarbon sensitivity of Mutatox was in general similar to that reported in the Ames test. Surficial sediment samples were collected, extracted with dichloromethane, evaporated and concentrated under nitrogen, dissolved in dimethyl sulfoxide, assayed for acute toxicity and genotoxicity, and compared with reference sediments. Samples with low EC50 values, and determined to be genotoxic, were detected in Massalina Bayou, Watson Bayou, East Bay, and St. Andrew Bay–East in St. Andrew Bay as well as Bayou Grande, Bayou Chico, and Bayou Texar in Pensacola Bay. An overview of these data sets analyzed by Spearman rank correlation showed a significant correlation between acute toxicity and genotoxicity (p &lt; 0.05). Microtox and Mutatox in tandem was a sensitive, cost-effective, and rapid (&lt;24 h) screening tool that identified troublesome areas of pollution and assessed the potential sediment toxicity of lipophilic contaminants in aquatic ecosystems.
Calibrating the uptake kinetics of semipermeable membrane devices using exposure standards
Authors: Booij Kees , Sleiderink Hedwig M , Smedes Foppe 
Published: March 2010

Abstract
Organic contaminant exchange kinetics between semipermeable membrane devices (SPMDs) and water were studied in two suspensions of estuarine and marine sediments under conditions of high and low turbulence over a period of 56 d. Prior to exposure, the SPMDs were spiked with a number of exposure standards not occurring in the environment. The release rate of these compounds was used as an independent measure of the exchange kinetics between the SPMD and water. The uptake rates of chlorobenzenes, polychlorinated biphenyls, (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were lower by a factor of three under conditions of low turbulence. For compounds with a log octanol–water partition coefficient (Kow) &gt; 5.5 the uptake rate was constant during the entire period. Within each compound class, uptake rate constants correlated well with log Kow. The uptake rate constants of PAHs were lower than those of PCBs and chlorobenzenes by a factor of 10, but these estimates probably are artificially low due to an overestimation of the aqueous PAH concentrations. Release rate constants of the exposure standards fell within the range of the uptake rate constants of chlorobenzenes and PCBs, although with poor precision. Suggestions for improving the measurement of exchange rate constants of exposure standards are presented. The role of triolein in the exchange kinetics is shown to be minor.
Effect of pH on complexation of Fe(III) with fulvic acids
Authors: da Silva Joaquim C G Esteves , Machado Adélio A S C , Oliveira César J S 
Published: March 2010

Abstract
The interaction of Fe(III) with two samples of fulvic acids (FAs) extracted from a pinewood soil (FA2: horizon 0–10 cm; FA3: horizon 10–25 cm) was monitored by synchronous fluorescence (SyF) spectroscopy at four pH values (3, 4, 5, and 6). Spectral data were preprocessed by SIMPLISMA, a self-modeling curve-resolution method, and from the calculated quenching profiles, equilibrium parameters for the interaction of Fe(III) and FAs were obtained (conditional stability constants [Kcs] and ligand site concentrations). The calculated log Kcs were (I = 0.1 M KNO3; standard deviation in parentheses): FA2, pH = 3, 4.9 (2), pH = 4, 4.7 (2), pH = 5, 5.1 (4), and pH = 6, 5.1 (1); FA3, pH = 3, 5.48 (1); pH = 4, 4.96 (7), pH = 5, 4.89 (1), and pH = 6, 5.1 (2), where I is the ionic strength. These results show that FA forms quite stable soluble complexes with Fe(III) in the acid pH range.
The functional integrity of northern leopard frog (Rana pipiens) and green frog (Rana clamitans) populations in orchard wetlands. I. Genetics, physiology, and biochemistry of breeding adults and young-of-the-year
Authors: Harris Megan L , Bishop Christine A , Struger John , van den Heuvel Michael R , Van Der Kraak Glen J , Dixon D George , Ripley Brian , Bogart James P 
Published: March 2010

Abstract
Northern leopard frogs (Rana pipiens) and green frogs (Rana clamitans) were evaluated at eight wetland sites, four of which were within apple orchards, to determine if environmental changes associated with orchard management affected measured biological parameters. Size, age, genetic variation, condition indices, levels of circulating steroid hormones, 7-ethoxyresorufin-O-deethylase activity (EROD), and organochlorine and organophosphorus residues in breeding males sampled at pond sites in orchards were compared to the same parameters measured in breeding males from reference sites. Also, the size and physiological condition of young-of-the-year captured in orchard and reference ponds were compared. No evidence of a reduction in genetic variation was found in populations of either species at any sites, but unexpectedly high average heterozygosity values (0.191–0.282) in concert with low overall fixation indices (0.012–0.059) in adults of both species did suggest that pond populations were interacting with neighboring populations in nonorchard habitats. Few significant differences in levels of circulating steroid hormones or condition indices of breeding males were found among sites. Significant EROD induction in male green frogs collected from one orchard site during one sampling event was the only indication that a metabolic challenge due to presence of cytochrome P450-inducing toxicants may have existed, whereas elevated concentrations of organochlorines (dichlorodiphenyltrichloroethane [DDT]- or endosulfan-related) in green frog tissues suggested that frogs at three orchard sites were taking up pesticides. Significant differences in size of equivalent-age male and juvenile leopard frogs and green frogs occupying different study sites suggested that suboptimal habitat characteristics existed at one or two of the four orchard sites. However, site-specific habitat deficiencies could not be related to orchard study sites in general, and, thus, wetlands in apple orchards appeared to provide viable breeding habitat for both northern leopard frogs and green frogs.
Reproduction and polychlorinated biphenyls inFundulus heteroclitus(Linnaeus) from new bedford harbor, massachusetts, USA
Authors: Black Dianne E , Gutjahr-Gobell Ruth , Pruell Richard J , Bergen Barbara , Mills Lesley , McElroy Anne E 
Published: March 2010

AbstractThis investigation evaluated polychlorinated biphenyl (PCB) accumulation, survival, and reproduction in Fundulus heteroclitus from four stations along a gradient of increasing sediment contamination from West Island in Buzzards Bay, Massachusetts, USA, to the most contaminated area of the New Bedford Harbor, Massachusetts, USA, Superfund site. Fish collected during their natural spawning season were held in the laboratory for 5 weeks. Liver concentrations of non-ortho- and mono-ortho-PCBs averaged 0.461, 9.48, 20.8, and 29.3 μg/g dry weight, with dioxin toxic equivalent concentrations (TEQs) of 0.006, 0.132, 0.543, and 1.56 ng/g; differences among stations were statistically significant. Females from two stations within the Superfund site had significantly greater mortality (30 and 23%) compared to those within West Island (0%), and growth was reduced. Progeny of fish from the most contaminated station exhibited significantly reduced survival (49%) and greater incidence of spinal abnormalities (26%) compared to those from West Island (70% survival, 7% spinal abnormalities). No differences in egg production or food consumption were observed. A significant residue-effect relationship was found between TEQs of liver PCBs and female mortality, consistent with that determined previously from laboratory exposures and validating TEQ as an effects indicator. Embryo and larval survival were inversely related to maternal liver TEQ.
Evaluation of log KOW and tissue lipid content as predictors of chemical partitioning to fish tissues
Authors: Bertelsen Sharon L , Hoffman Alex D , Gallinat Carol A , Elonen Colleen M , Nichols John W 
Published: March 2010

Abstract
In vitro equilibrium chemical partition coefficients were determined for six chemicals in selected tissues from four species of fish. Log-transformed values were then regressed in stepwise fashion against chemical log octanol/water partition coefficient (Kow) and the log of tissue lipid content to derive a series of linear one- and two-variable models. Equations derived for fat indicate that n-octanol is a good surrogate for nonpolar lipid in the range of chemical log Kow tested (1.46 &lt; log Kow &lt; 4.04). These equations also support the conclusion that previously developed Kow-bioconcentration factor relationships are largely a reflection of chemical accumulation in fat. Fitted slope and intercept terms for “lean” tissues differed from those expected from chemical partitioning to lipid only and were instead consistent with the suggestion that partitioning to nonlipid-nonwater cellular constituents contributes substantially to chemical accumulation. A general equation is presented for prediction of tissue/water and blood/water partitioning from chemical log Kow and tissue (or blood) lipid content. It is suggested, however, that tissue- and blood- specific equations be used to estimate the tissue/blood partitioning relationships needed for kinetic modeling efforts.
Biodegradation of resorcinol and catechol by denitrifying enrichment cultures
Authors: Milligan Peter W , Häggblom Max M 
Published: March 2010

Abstract
We examined the anaerobic degradation of catechol (1,2-dihydroxybenzene), resorcinol (1,3-dihydroxybenzene), and hydroquinone (1,4-dihydroxybenzene), which are widely used industrial reagents and central intermediates in the biodegradation of numerous aromatic compounds. Anaerobic denitrifying enrichments were established with sediments from an estuarine tidal strait in New Jersey, USA. The three dihydroxybenzene isomers were provided as a sole carbon source in separate enrichment series. Resorcinol- and catechol-degrading consortia used their respective substrates over repeated feedings. Initial loss of hydroquinone was observed, but activity could not be maintained. The degradation of resorcinol and catechol was coupled to denitrification and was dependent on nitrate or nitrite as an electron acceptor. Nitrate consumption and N2 production corresponded to the stoichiometric values predicted for the oxidation of dihydroxybenzenes to CO2.
Suppression of chlorothalonil degradation in soil after repeated application
Authors: Motonaga Kei , Takagi Kazuhiro , Matumoto Satoshi 
Published: March 2010

Abstract
Mechanisms of degradation suppression of chlorothalonil after repeated application were investigated. Under laboratory conditions, soil was treated sequentially with 40 mg/kg dry weight of chlorothalonil. This resulted in the degradation suppression of chlorothalonil and accumulation of the metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile (TPN-OH) in soil. After pretreatment with three kinds of chlorothalonil metabolite, only TPN-OH was found to suppress chlorothalonil degradation in soil. After the pretreatment of TPN-OH, residual chlorothalonil in soil at 1 week after application was 9 to 11% higher than those with pretreatment with other metabolites and control. The TPN-OH pretreatment also suppressed soil respiration and TPN-OH was more persistent in soil than chlorothalonil, indicating that toxicity of residual TPN-OH may suppress the degradation of chlorothalonil in soil.
Effects of tributyltin, linear alkylbenzenesulfonates, and nutrients (nitrogen and phosphorus) on nucleoid-containing bacteria
Authors: Prior Susanne , Riemann Bo 
Published: March 2010

Abstract
Effects of tributyltin (TBT) and linear alkylbenzenesulfonate (LAS) on the number of nucleoid-containing bacteria (NCB) were examined in 15 marine enclosures situated in Knebel Vig, Denmark. Nucleoid-containing bacteria were enumerated using a newly revised methodological approach including glutaraldehyde fixed 4′,6′ diamidino-2-phenylindole (DAPI) preparations rinsed with 2-propanol. Additions of TBT (0.0025–9.7 nM) reduced the number of NCB up to 62%, whereas additions of LAS (15 μM) increased the numbers. Total counts were not affected by the two toxicants. Values of no-observed-effect concentration, lowest-observed-effect concentration, and concentration at 30% effectiveness for TBT on NCB were 0.020, 0.16, and 0.0036 nM, respectively. These values are much lower than those previously reported by other techniques and are similar to or lower than TBT concentrations measured in harbors and coastal sea regions, suggesting that natural bacterial assemblages in many marine environments are toxified by TBT. Additions of nutrients stimulated both total counts (twofold) and NCB (fourfold), whereas addition of LAS + nutrients stimulated only NCB. Results from two diel studies demonstrated that NCB varied more on a diel scale than did total counts. Nevertheless, the effects of the two toxicants on NCB were significantly higher than the measured diel changes, suggesting that NCB can be used as a sensitive parameter to test effects of toxicants on pelagic ecosystems.
Accumulation of halogenated aromatic hydrocarbons and activities of cytochrome P450 and glutathiones-transferase in CRABS (Eriocheir japonicus) from Japanese Rivers
Authors: Ishizuka Mayumi , Sakiyama Takanori , Iwata Hisato , Fukushima Minoru , Kazusaka Akio , Fujita Shoichi 
Published: March 2010

AbstractThe hepatopancreases of freshwater crabs (Eriocheir japonicus) collected from three Japanese rivers (Barato, Shiribetsu, and Tone) were analyzed for planar halogenated aromatic hydrocarbons (HAHs), including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (PCBs). The hepatic glutathione S-transferase (GST)-dependent enzyme activities in the crab hepatopancreas were also measured to examine their potential as biomarkers for the contaminants. Crabs from the Tone River, which runs through industrial, agricultural, and urban areas, have the highest concentrations of HAHs (4,100 pg/g fat weight), followed by those from the Barato River (2,430-2,970 pg/g fat weight), whereas crabs from the Shiribetsu River were relatively less contaminated (1,350–1,800 pg/g fat weight). Identification of numerous PCDD and PCDF congeners in crabs from all three rivers provided evidence that one of the major sources of PCDDs and PCDFs was waste incineration. In addition, crabs from the Barato and Shiribetsu Rivers were notably contaminated with 1,3,6,8- and 1,3,7,9-TeCDD congeners, which suggests that a possible source was chlornitrofen, which has been extensively used in paddy fields as a herbicide. Calculation of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin toxic equivalents (TEQs) showed that the causal contaminants of higher TEQs in crabs from the Tone River (94.7 TEQ picograms per gram fat weight) were PCDDs and PCDFs, although the most important contributor to the total TEQs was coplanar PCBs (49.95%). The crab hepatopancreas appeared to have abilities to transfer glutathione to 1-chloro-2,4-nitrobenzene (CDNB) and 3,4-dichloronitrobenzene (DCNB). The crabs with the highest TEQ levels showed the highest GST activities. The current results and our previous data lead us to conclude that cytochrome P450 and GST-dependent enzyme activities (benzo[a]pyrene hydroxylation and CDNB and DCNB conjugation) in freshwater crab hepatopancreases are likely to be useful biomarkers for the contamination of planar aromatic hydrocarbons such as benzo[a]pyrene, PCDDs, PCDFs, and coplanar PCBs.
Induction of erod activity in HEPA-1 mouse hepatoma cells and estrogenicity in mcf-7 human breast cancer cells by extracts of pulp mill effluents, sludge, and sediment exposed to effluents
Authors: Koistinen Jaana , Soimasuo Markus , Tukia Kari , Oikari Aimo , Blankenship Alan , Giesy John P 
Published: March 2010

AbstractExtracts of effluents and sludges from the primary and secondary clarifiers of an activated sludge treatment plant at a Finnish bleached kraft pulp and paper mill were analyzed in two cell bioassays. Total dioxin-like activities were determined by measuring the induction of ethoxyresorufin-O-deethylase (EROD) activity in Hepa-1 mouse hepatoma cells. Estrogenicity was studied by measuring luciferase activity in MCF-7 ERE-luc, which are MCF-7 human breast cancer cells stably transfected with an estrogen-responsive element linked to a luciferase promoter. Sediments collected near the pulp mill and from other sites in Lake Saimaa as well as fillets of whitefish exposed to effluents were examined and EROD activity was determined for complex mixtures of compounds extractable with dichloromethane (DCM) from the pulp mill effluent or compounds collected by semipermeable membrane devices (SPMDs) from the same effluent. Extracts of effluents, particulates, SPMDs, and sludges all caused measurable EROD induction. Because the induction potencies of the total DCM extract and the fraction of neutral compounds were similar, it was concluded that most of the EROD induction in pulp mill effluents was due to neutral compounds. Sediment collected from the vicinity of the pulp mill had greater EROD-inducing potency compared to that of the control sites from the same lake. Induction of EROD potencies of muscle extracts of whitefish exposed to diluted effluents were not significantly greater than those of control fish exposed to dilution water only. All extracts contained some estrogen agonist activity when tested in the MCF-7 bioassay.
Use of sublethal endpoints in sediment toxicity tests with the amphipod Hyalella azteca
Authors: Ingersoll Christopher G , Brunson Eric L , Dwyer F James , Hardesty Doug K , Kemble Nile E 
Published: March 2010

Abstract
Short-term sediment toxicity tests that only measure effects on survival can be used to identify high levels of contamination but may not be able to identify marginally contaminated sediments. The objective of the present study was to develop a method for determining the potential sublethal effects of contaminants associated with sediment on the amphipod Hyalella azteca (e.g., reproduction). Exposures to sediment were started with 7- to 8-d-old amphipods. On day 28, amphipods were isolated from the sediment and placed in water-only chambers where reproduction was measured on day 35 and 42. Typically, amphipods were first in amplexus at about day 21 to 28 with release of the first brood between day 28 to 42. Endpoints measured included survival (day 28, 35, and 42), growth (as length and weight on day 28 and 42), and reproduction (number of young/female produced from day 28 to 42). This method was used to evaluate a formulated sediment and field-collected sediments with low to moderate concentrations of contaminants. Survival of amphipods in these sediments was typically &gt;85% after the 28-d sediment exposures and the 14-d holding period in water to measure reproduction. Reproduction was more variable than growth; hence, more replicates might be needed to establish statistical differences among treatments. Previous studies have demonstrated that growth of H. azteca in sediment tests often provides unique information that can be used to discriminate toxic effects of exposure to contaminants. Either length or weight can be measured in sediment tests with H. azteca. However, additional statistical options are available if length is measured on individual amphipods, such as nested analysis of variance that can account for variance in length within replicates. Ongoing water-only studies testing select contaminants will provide additional data on the relative sensitivity and variability of sublethal endpoints in toxicity tests with H. azteca.
Response of phytoplankton photosynthesis and growth to the aquatic herbicide hydrothol 191
Authors: Ruzycki Elaine M , Axler Richard P , Owen Christopher J , Martin Todd B 
Published: March 2010

Abstract
The herbicide Hydrothol 191, the amine salt of endothall, has been widely used for the control of aquatic vegetation and filamentous algae for over 30 years. Recently, it has been proposed for use in secondary wastewater stabilization ponds for control of algal-related total suspended solids (TSS) prior to and during discharge. However, published information on the effect of Hydrothol on algal growth and species-specific sensitivity is limited. We performed 96-h unialgal toxicity tests to determine effects on growth and photosynthetic activity on a number of species commonly found in these wastewater ponds. Results indicated differences in sensitivity to the herbicide between chlorophytes and cyanophytes. The 48-h 50% effective concentration (EC50) values for the blue-green Microcystis were 0.04 to 0.08 mg/L for cell growth and 0.04 to 0.22 mg/L for photosynthetic capacity; values for Phormidium were 0.05 mg/L and 0.097 mg/L for the same endpoints. The Chlorococcales greens Chlorella and Scenedesmus and the flagellated green Chlamydomonas showed much lower sensitivity to Hydrothol. The 48-h EC50 values for Chlorella were &gt;0.60 mg/L for both cell growth and photosynthetic capacity while values for Scenedesmus were &gt;0.60 mg/L and 0.23 mg/ L for the same parameters. The flagellate Chlamydomonas required 0.52 mg/L and 0.42 mg/L, respectively, to reduce cell density and photosynthetic capacity 50% below controls. These data suggest that reductions in the amount of Hydrothol needed to reduce algal-related TSS may be possible when the population is dominated by blue-greens that could be economically beneficial and allow for applications with reduced environmental concerns.
Acute toxicity of fire-retardant and foam-suppressant chemicals to early life stages of chinook salmon (Oncorhynchus tshawytscha)
Authors: Buhl Kevin J , Hamilton Steven J 
Published: March 2010

AbstractLaboratorys studies were conducted to determine the acute toxicity of three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F), and two fire-suppressant foams (Phos-Chek WD-881 and Ansul Silv-Ex) to early life stages of chinook salmon, Oncorhynchus tshawytscha, in hard and soft water. Regardless of water type, swim-up fry and juveniles (60 and 90 d posthatch) exhibited similar sensitivities to each chemical and these life stages were more sensitive than eyed eggs. Foam suppressants were more toxic to each life stage than the fire retardants in both water types. The descending rank order of toxicity for these chemicals tested with swim-up fry and juveniles (range of 96-h median lethal concentrations [LC50s]) was Phos-Chek WD-881 (7–13 mg/L) &gt; Ansul Silv-Ex (11–22 mg/L) &gt; Phos-Chek D75-F (218–305 mg/L) &gt; Fire-Trol GTS-R (218–412 mg/L) &gt; Fire-Trol LCG-R (685–1,195 mg/L). Water type had a minor effect on the toxicity of these chemicals. Comparison of acute toxicity values with recommended application concentrations indicates that accidental inputs of these chemicals into stream environments would require substantial dilution (237- to 1,429-fold) to reach concentrations equivalent to their 96-h LC50s.