bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence and fate of 2,3,4,6-tetrachlorophenol and pentachlorophenol in limnocorrals
Authors: Liber Karsten , Solomon Keith R , Carey John H 
Published: March 2010

Abstract
Three separate limnocorral experiments were conducted to assess the fate and effects of a commercial 2,3,4,6-tetrachlorophenol (TeCP) formulation (DIATOX®; 19.4% TeCP, 4.8% pentachlorophenol [PCP], 75.8% “inert” buffers) in an aquatic ecosystem. Nominal treatment concentrations for experiments 1 and 2 were 0.075 and 0.75 mg active ingredient (a.i.)/L and 0.75 and 1.50 mg a.i./L DIATOX®, respectively, with three replicates of each treatment. Pesticide was applied in the morning for experiment 1 and in the evening for experiment 2. For Experiment 3, unreplicated concentrations of 0.1, 0.25, 0.5, 1.0, 2.0, 4.0, and 7.3 mg a.i./L DIATOX® were chosen; pesticide was applied in the evening. In all three experiments, the pesticide was applied as a single, uniform surface treatment. Both TeCP and PCP dissipated rapidly from the water of treated limnocorrals. Times to 50% dissipation for TeCP and PCP in the integrated water column were generally similar within experiments but ranged from 0.4 to 1.1 d following the morning application of experiment 1 to 3.4 to 7.3 d following the evening applications of experiments 2 and 3. The faster initial dissipation of TeCP and PCP from the water following the morning application implicated photolysis as the primary degradation mechanism, as did the faster dissipation of chlorophenols from the surface layer than from other water depths during experiment 2. Aqueous dissipation rates for both compounds from the integrated water column were similar in all three experiments after the initial mixing period (1–4 d); the three-experiment average first-order rate coefficient for either compound after day 4 was 0.09/d. From a mass balance perspective, the majority of the chlorophenols remained in the water column. Neither compound accumulated in the sediments to any significant extent (&lt; 0.1% of applied mass), but sediment-associated residues did dissipate at a considerably slower rate than residues in the water column. From 97 to &gt;99% of the applied chlorophenols had dissipated from the water of treated enclosures by the end of the various experiments (42–63 d).
Toxicity and bioaccumulation of a mixture of heavy metals inChironomus tentans(Diptera: Chironomidae) in synthetic sediment
Authors: Harrahy Elisabeth A , Clements William H 
Published: March 2010

AbstractThis research investigated toxicity and bioaccumulation of a mixture of Cd, Cu, Pb, and Zn in Chironomus tentans in synthetic sediment, and compared predicted to measured steady-state bioaccumulation factors (BAFs). In a toxicity test, C. tentans were exposed to various dilutions of a base concentration (1.0 X) of a mixture of the four metals (5 μg/g Cd, 10 μg/g Cu, 70 μg/g Pb, and 300 μg/g Zn) in synthetic sediment. Mortality ranged from 17 to 100%. To measure bioaccumulation of the metals, C. tentans were exposed to 0.35 × the base concentration for a period of up to 14 d in two uptake tests. Bioaccumulation of all four metals increased over the 14-d uptake phases. Concentrations of metals in chironomids were significantly correlated with exposure time in the uptake phases. Only concentrations of copper approached background levels after 7 d depuration. Uptake rate coefficients and elimination rate constants were determined for each metal. Bioaccumulation factors were highest for Cd and lowest for Pb. With the exception of Pb, steady-state BAFs were within a factor of about two of those calculated using the first-order kinetic model. The high BAFs calculated may indicate greater bioavailability in synthetic sediment. Studies comparing toxicity and bioaccumulation of natural and synthetic sediments are necessary before the use of synthetic sediments is widely adopted.
Evidence that variability in ambient fathead minnow short-term chronic tests is due to pathogenic infection
Authors: Kszos Lynn Adams , Stewart Arthur J , Sumner James R 
Published: March 2010

Abstract
An examination of results from ambient fathead minnow subchronic toxicity tests identified a common characteristic of the tests, which manifests itself as a large among-replicate and between-test variance in survival. The unusual replicate-specific mortality in tests with ambient water appears to be due to pathogenic bacteria or fungi. This finding is based on the following facts: a comparison of survival among replicates in effluents and ambient waters showed that when mean survival was low (40-70%), among-replicate variation for ambient tests was greater than it was for the effluent tests; in 63 tests conducted at three locations over nearly 3 years, treating the water with ultraviolet (UV) light improved survival; a seasonal pattern to survival was present at ambient sites; survival was higher when minnows were separated by using 1 minnow/beaker rather than the standard system of 10 minnows/beaker; and survival tended to be higher in ambient sites contaminated with low levels of chlorine. The existence of the pathogen(s) does not mean that the test cannot be used effectively to assess toxicity of ambient waters; instead, it indicates that factors other than toxicity may need to be taken into consideration when interpreting the results.
Quantitative structure-activity relationships for weak acid respiratory uncouplers to Vibrio fisheri
Authors: Schultz T Wayne , Cronin Mark T D 
Published: March 2010

Abstract
Acute toxicity values (5- and 30-min Vibrio fisheri 50% luminescence inhibition) of 16 organic compounds thought to elicit their response via the weak acid respiratory uncoupling mechanism of toxic action were secured from the literature. Regression analysis of toxicities revealed that a measured 5-min V. fisheri potency value can be used as a surrogate for the 30-min value. Regression analysis of toxicity (30-min for potency [log pT 30−1]) versus hydrophobicity, measured as the 1-octanol/water partition coefficient (log Kow), was used to formulate a quantitative structure-activity relationship (QSAR). The equation log pT 30−1 = 0.489(log Kow) + 0.126 was found to be a highly predictive model (r2 adj. = 0.848). This V. fisheri QSAR is statistically similar to QSARs generated from weak acid uncoupler potency data for Pimephales promelas survivability and Tetrahymena pyriformis population growth impairment. This work, therefore, suggests that the weak acid respiratory uncoupling mechanism of toxic action is present in V. fisheri, and as such is not restricted to mitochondria-containing organisms.
Demonstration of a toxicological risk ranking method to correlate measures of ambient toxicity and fish community diversity
Authors: Hartwell S Ian 
Published: March 2010

Abstract
The goal of this study was to assess a new toxicological risk ranking model, field validate it with results from a battery of sediment and water column bioassays, and identify correlations of model output with fish community and population metrics. The model has five components: severity of effect, degree of response, bioassay variability, consistency, and number of measured endpoints. The model can reliably reduce an array of ambient toxicity data into a site-specific metric that is appropriate for comparisons with other metrics, such as Index of Biotic Integrity (IBI) or community diversity indices. The model is tolerant of variable amounts of data between stations. It does not generate probability limits without repeated sampling. The model can identify trends between sampling stations and document where chemical contamination is contributing to community impacts as well as where toxicological impacts are not likely to be contributing to observed population level impairment. The model was evaluated with field/laboratory data. Test sites were located in tributaries of Chesapeake Bay watersheds that are impacted by industrial, urban, and agricultural land use patterns. The toxicological risk scores correlate with fish community health metrics. The strongest correlations were between sediment toxicity risk and bottom trawl fish community diversity index.
Comparison of three marine screening tests and four Oslo and Paris commission procedures to evaluate toxicity of offshore chemicals
Authors: Weideborg Mona , Vik Eilen Arctander , Øfjord Gro Daae , Kjønnø Ocelie 
Published: March 2010

Abstract
The results from the screening toxicity tests Artemia salina, Microtox®, and Mitochondria RET test were compared with those obtained from OSPAR (Oslo and Paris Commissions)-authorized procedures for testing of offshore chemicals (Skeletonema costatum, Acartia tonsa, Abra alba, and Corophium volutator). In this study 82 test substances (26 non-water soluble) were included. The Microtox test was found to be the most sensitive of the three screening tests. Microtox and Mitochondria RET test results showed good correlation with results from Acartia and Skeletonema testing, and it was concluded that the Microtox test was a suitable screening test as a base for assessment of further testing, especially regarding water-soluble chemicals. Sensitivity of Artemia salina to the tested chemicals was too low for it to be an appropriate bioassay organism for screening testing. A very good correlation was found between the results obtained with the Skeletonema and Acartia tests. The results indicated no need for more than one of the Skeletonema or Acartia tests if the Skeletonema median effective concentration or Acartia median lethal concentration was greater than 200 mg/L. The sediment-reworker tests (A. alba or C. volutator) for chemicals that are likely to end up in the sediments (non-water soluble or surfactants) should be performed, independent of results from screening tests and other OSPAR species.
A quasi-steady-state pollutant flux methodology for determining sediment quality criteria
Authors: Valsaraj Kalliat T , Thibodeaux Louis J , Reible Danny D 
Published: March 2010

Abstract
A methodology for estimating quasi-steady-state flux of pollutants from bed sediments to water and air is presented. This is illustrated using the example case of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in a sediment bed. The rate of transport from the bed sediment was found to be important in determining the concentration of TCDD along its pathway from sediment to air. The concentration in the water column that leads to exposure to aquatic species was found to scale in proportion to the flux from the sediment and not to the pollutant concentration in the sediment. The sediment-side processes were found to provide the dominant resistance to mass transfer of pollutant. Both transport (rates) and thermodynamics (equilibrium partition constants) are shown to be important in setting sediment quality criteria. These should be incorporated in the next generation of sediment quality criteria.
A new method for simultaneous quantification of uncoupling and inhibitory activity of organic pollutants in energy-transducing membranes
Authors: Escher Beate I , Snozzi Mario , Häberli Katharina , Schwarzenbach René P 
Published: March 2010

AbstractA new, mechanistically based approach is presented for the quantitative determination of the uncoupling and inhibitory activity of compounds interfering with energy transduction. Time-resolved spectroscopy of single-turnover events in the photosystem of the photosynthetic bacterium Rhodobacter sphaeroides can quantitatively distinguish uncoupling from inhibition. The decay kinetics of the membrane potential after a single turnover flash are used as a measure of uncoupling activity, and the redox kinetics of several components of the electron transfer chain are used as indicators of specific inhibition at various potential inhibitory sites. Results are presented for 21 nitrated and chlorinated phenols, some reference uncouplers, and some anisoles. Inhibition was exclusively detected at one specific quinone binding site, the quinone reductase site Qi. For most phenols, uncoupling was observed at lower concentrations than inhibition with the exception of alkylated 2,6-dinitrophenols and 2,4,6-trichlorophenol, where both effects occurred in the same concentration range. No direct correlation was observed between the uncoupling and inhibitory activity of a given compound. The data obtained with this new method correlate well with data from various bioassays on energy-transducing systems, indicating that this method may also be well suited as a screening tool for compounds suspected to interfere with energy transduction.
Effects of piperonyl butoxide and β-naphthoflavone on cytochrome P4501A expression and activity in Atlantic salmon (Salmo salarL.)
Authors: Grøsvik Bjørn Einar , Larsen Håvard E , Goksøyr Anders 
Published: March 2010

AbstractThe effects of piperonyl butoxide (PBO) and β-naphthoflavone (BNF) on cytochrome P4501A (CYP1A) expression and activity in juvenile Atlantic salmon (Salmo salar L.) with regard to time and temperature was investigated. The time exposure study was performed at 8 °C, and the results show that PBO, although acutely functioning as a CYP1A inhibitor, is able to induce CYP1A expression in salmon liver. Both PBO and BNF give highest induction of CYP1A mRNA 48 h after intraperitoneal injection (five- and 14-fold, respectively). The mRNA levels induced by PBO and BNF were sustained during the 8 d of the experiment (four- and 11-fold, respectively). The CYP1A protein content measured by enzyme-linked immunosorbent assay demonstrated the highest induction by PBO 8 d after exposure (eightfold) and by BNF 4 d after exposure (11-fold). Activity of CYP1A measured by ethoxyresorufin-O-deethylase (EROD) demonstrated inhibition after PBO treatment the first 24 h after exposure, followed by threefold induction from 48 h and to the end of the experiment (8 d). β-Naphthoflavone strongly induced EROD activity, with the highest levels occurring 4 d after treatment (56-fold) and 8 d after treatment (22-fold). In the temperature study, the results demonstrated temperature compensation, as salmon acclimated to 7°C for 3 weeks had a significantly higher EROD activity than those acclimated to 11 and 15°C. This was not reflected in significantly higher levels of reduced nicotinamide adenine dinucleotide phosphate cytochrome c reductase activity or CYP1A protein. The inductive properties of PBO and BNF on CYP1A expression was also demonstrated in primary cultures of salmon hepatocytes.
Reductive transformation and sorption of cis- and trans-1,2-dichloroethene in a metallic iron–water system
Authors: Allen-King Richelle M , Halket Richard M , Burris David R 
Published: March 2010

Abstract
Reductive transformation kinetic and sorption coefficients were determined for both cis- and trans-1,2-dichlo-roethene (DCE) in batch systems with zero-valent iron and water. Sorption quasi-equilibrium occurred rapidly (&lt;1.1 h) for both compounds. Freundlich-type isotherms adequately described sorption over the measured concentration range. The magnitude of sorption was greater for trans-1,2-DCE than for the more soluble cis-1,2-DCE, indicating a possible influence of hydrophobicity. The trans-isomer was more reactive than the cis-isomer. The reaction order (95% confidence intervals) for trans-1,2-DCE was 1.22 (0.97–1.48), and for cis-1,2-DCE was 1.77 (0.92–2.63) and 1.64 (1.05–2.23) in relatively high and low initial concentration experiments, respectively. The fact that the reaction order for the cis-isomer could not be reduced to unity by assuming that the bulk of observed sorption was to nonreactive sorption sites suggests that either the assumption may not be valid or that a more complex process exists for this isomer. Chloride was produced by the transformation reaction and chlorine mass balances for the batch systems were 80 to 85%. Other products observed were acetylene, ethene, ethane, C3-C5 alkanes, and vinyl chloride.
Distribution of polycyclic aromatic hydrocarbons in southern Chesapeake Bay surface water: Evaluation of three methods for determining freely dissolved water concentrations
Authors: Gustafson Kurt E , Dickhut Rebecca M 
Published: March 2010

AbstractGas sparging, semipermeable-membrane devices (SPMDs), and filtration with sorption of dissolved polycyclic aromatic hydrocarbons (PAHs) to XAD-2 resin were evaluated for determining the concentrations of freely dissolved PAHs in estuarine waters of southern Chesapeake Bay at sites ranging from rural to urban and highly industrialized. Gas sparging had significant sampling artifacts due to particle scavenging by rising bubbles, and SPMDs were kinetically limited for four-ring and larger PAHs relative to short-term temporal changes in water concentrations. Filtration with sorption of the dissolved contaminant fraction to XAD-2 resin was found to be the most accurate and feasible method for determining concentrations of freely dissolved PAHs in estuarine water. Concentrations and distribution coefficients of dissolved and particulate PAHs were measured using the filtration/ XAD-2 method. Concentrations of PAHs in surface waters of southern Chesapeake Bay were higher than those reported for the northern bay; concentrations in the Elizabeth River were elevated relative to all other sites. A gradient for particulate PAHs was observed from urban to remote sites. No seasonal trends were observed in dissolved or particle-bound PAH fractions at any site. Distributions of dissolved and particulate PAHs in surface waters of the Chesapeake Bay are near equilibrium at all locations and during all seasons.
Aerobic biodegradation of (14C)-sarafloxacin hydrochloride in soil
Authors: Marengo Jose R , Kok Rebecca A , O'Brien Kelly , Velagaleti Ranga R , Stamm John M 
Published: March 2010

Abstract
The aerobic biodegradation of sarafloxacin hydrochloride, a fluoroquinolone antibiotic registered for use against poultry diseases, was tested in three soils: loam, silt loam, and sandy loam. Sarafloxacin treatment demonstrated mineralization to 14CO2 amounting to 0.58%, 0.49%, and 0.57% in loam, silt loam, and sandy loam soils, respectively, at the termination of the test. The extractability of sarafloxacin from soil in acetonitrile and water (ACN:H2O, 1:1, v/v) was less than 1% of the applied radioactivity. This was followed by extraction with pipemidic acid (a quinolone with structural similarity to sarafloxacin) and KOH (PIP:KOH), which resulted in ∼25% extractability in loam, ∼73% in silt loam, and ∼80% in sandy loam soils, with extractability increasing with decreasing organic matter content (5.8%, 2.5%, and 1.3%, respectively, for the three soils). The high-performance liquid chromatography (HPLC) analysis of ACN:H2O extractable radioactivity showed several components, all of which were less than 1% of the applied radioactivity. Hence, no attempt was made to characterize these components. The HPLC analysis of PIP:KOH extracts demonstrated two major components, one with a retention time of ∼4 to 5 min (designated polar component), the other component, sarafloxacin, with a retention time of ∼35 min. The components present in ACN:H2O or PIP:KOH extracts were not significantly different at day zero or at termination, prompting experiments that resulted in the following observations. Sarafloxacin standard exposed to extraction solvents (PIP:KOH and ACN:H2O) showed no degradation, suggesting stability of the test article in extraction solvents. Component profiles in sterile soils were similar to those in nonsterile soils, suggesting that the formation of the polar degradate component of sarafloxacin is an abiotic phenomenon. Experiments conducted with sand spiked with sarafloxacin showed very little or no transformation, suggesting that the degradation is a soil-related phenomenon. The polar component was converted to sarafloxacin when the extracts were subjected to acid hydrolysis.
Contaminants in white sturgeon (Acipenser transmontanus) from the upper Fraser River, British Columbia, Canada
Authors: MacDonald Donald D , Ikonomou Michael G , Rantalaine Anna-Lea , Rogers I Hal , Sutherland David , Van Oostdam Jay 
Published: March 2010

Abstract
Four white sturgeon were collected from the upper Fraser River near Prince George, British Columbia, Canada, in the fall of 1991 and 1992. Two additional fish were taken from the Fraser River near Williams Lake, some 250 km downstream of Prince George. Samples of white muscle, red muscle, liver, and roe were analyzed for metals, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho and mono–ortho polychlorinated biphenyls (PCBs), and chlorophenols to determine whether the tissues of this species were acceptable for human consumption. The concentrations of mercury in the white muscle and liver of several fish from the upper Fraser River exceeded the provincial tissue residue criteria for people who consumed low quantities of fish (i.e., 210 g wet weight/week). The concentrations of PCDDs, PCDFs, and coplanar PCBs (expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents) in red muscle and liver of these fish exceeded the Health Canada working guidelines for the protection of human health. By comparison, white sturgeon collected in the lower Fraser River had much lower concentrations of metals and organic contaminants. The differences in contaminant burdens in fish from the two widely separated reaches of the river reflect their proximity to or distance from known contaminant sources.
PCBS, DDE, DDT, and TCDD-EQ in two species of albatross on Sand Island, Midway Atoll, North Pacific Ocean
Authors: Auman Heidi J , Ludwig James P , Summer Cheryl L , Verbrugge David A , Froese Kenneth L , Colborn Theo , Giesy John P 
Published: March 2010

Abstract
Concentrations of total polychlorinated biphenyls (PCBs) and organochlorine insecticides, including the 1 1,1-trichloro-2, 2′-bis-p-chlorophenyl-ethane (DDT) complex, were measured in the plasma of chicks and adults and in eggs of Laysan albatrosses (Diomedea immutabilis) and black-footed albatrosses (Diomedea nigripes) in a remote area of the central North Pacific Ocean. Significant differences in total concentrations of PCBs, DDT, and 1,1-dichloro-2,2′-bis-p-chlorophenyl-ethylene (DDE) in the plasma were detected between species and among sampling periods. Current concentrations of DDE in eggs of Laysan albatrosses are well below the threshold for eggshell thinning, based on the sensitivities of other fish-eating birds, whereas concentrations of DDE in eggs of black-footed albatrosses were approximately one-half of the threshold concentrations necessary for eggshell thinning. The shells of Laysan and black-footed albatross eggs are not currently exhibiting significant thinning that is resulting in population-level effects. Current concentrations of PCBs are near those that could be having subtle population-level effects in the black-footed albatross, but not in the Laysan albatross. The hazard posed to the albatrosses by current concentrations of PCBs was assessed by calculating a hazard quotient (HQ), based on composite dose–response relationships for other species. Dioxin equivalents (TEq) based on mammalian toxic equivalency factors resulted in the greatest HQ, which was near the concentration when embryo lethality and deformities are observed in fish-eating colonial waterbirds of the North American Great Lakes. Current concentrations of both PCBs and the DDT complex were similar to those in some species of piscivorous birds of the North American Great Lakes region.