bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the input pathway on the distribution of 1,2,3,4,7-pentachlorodibenzo-p-dioxin in an aquatic mesocosm
Authors: Friesen Kenneth J. , Segstro Mark D. , Webster G.R. Barrie , Muir Derek C.G. 
Published: March 2010

Abstract
The effect of the input pathway on the distribution of 1,2,3,4,7-pentachlorodibenzo-p-dioxin (P5CDD) in small-pond mesocosms was determined by introducing 14C-labeled dioxin (468 μg) into the water sorbed to sediment particles and by a surface sprayover in a water-miscible organic solvent. Rates of clearance from the water column were rapid and unrelated to the input method in either case, with pseudo-first-order half-lives (t1/2) of 0.38 ± 0.19 d (r2 = 0.81) and 0.57 ± 0.08 d (r2 = 0.98) for the particle-sorbed and sprayover applications, respectively, over the first 24 h after input. However, redistribution pathways were strongly influenced by the route of entry of P5CDD into the ecosystem. Ponds receiving a sprayover of P5CDD showed higher concentrations of the dioxin in surface microlayers with larger amounts also collected in air above these ponds. Concentrations of P5CDD in the bottom sediments of these ponds were significantly lower (0.6 ng/g dry weight) compared to concentrations in sediments of ponds receiving a sediment slurry input (1.2 ng/g dry weight). Evaluation of the results using several fugacity-based aquatic-fate models indicated that when P5CDD entered the aquatic ecosystem in the sorbed state, sedimentation dominated its redistribution. However, with a sprayover input, film-to-water transfer, partitioning and deposition to bottom sediment, volatilization, and photolytic degradation in surface microlayers were important processes affecting the fate of P5CDD in the mesocosm.
Growth and survival of three marine invertebrate species in sediments from the hudson-raritan estuary, New York
Authors: Rice Casimir A. , Plesha Paul D. , Casillas Edmundo , Misitano David A. , Meador James P. 
Published: March 2010

AbstractSediments in the Hudson-Raritan estuary are known to contain high concentrations of anthropogenic contaminants, and marine organisms from this region exhibit numerous contaminant-related effects. To assess the pattern of sediment toxicity in depositional areas of this region, and to compare lethal and sublethal end points for different bioassay organisms, three benthic marine invertebrate species were exposed to sediments from 17 sites in the Hudson-Raritan estuary. Growth and mortality of the polychaete Armandia brevis and the sand dollar Dendraster excentricus were measured in all 17 sediments, while mortality and reburial ability of the amphipod Rhepoxinius abronius were assessed in nine sediments. Growth of polychaetes was determined by measuring the difference in weight after a 20-d exposure, whereas growth of sand dollars was assessed by measuring the difference in length and weight after a 28-d exposure. Amphipod mortality and reburial tests were conducted using the standard 10-d sediment bioassay. Significant growth reduction of polychaetes and sand dollars occurred in 11 of 17, and 3 of 17 sediments, respectively. Polychaete weight and sand dollar length correlated inversely and significantly with total sediment concentration of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and some selected elements. In contrast, significant mortality of polychaetes and amphipods occurred in 1 of 17 and 2 of 9 sediments, respectively, and impaired reburial ability of amphipods was not observed. Results of this study demonstrate that sediment contamination at depositional sites with the Hudson-Raritan estuary has potential to cause deleterious biological effects in indigenous benthic organisms. In addition, sublethal growth bioassays using polychaetes and sand dollars appear to be more sensitive in measuring the effects of sediment contamination than does the mortality-based bioassay using the amphipod Rhepoxinius abronius.
Effects of naturally weathered Exxon valdez crude oil on mallard reproduction
Authors: Stubblefield William A. , Hancock Gregg A. , Prince Harold H. , Ringer Robert K. 
Published: March 2010

Abstract
A one-generation reproductive toxicity study and a direct eggshell application toxicity study were conducted using the mallard (Anas platyrhynchos) to assess the toxicity of naturally weathered North Slope crude oil (WEVC), obtained following the Exxon Valdez spill. In the reproductive study, birds were fed diets containing 0, 200, 2,000, and 20,000 mg of WEVC/kg diet. No significant differences (p ≤ 0.05) in mortality, body weight, food consumption, reproductive parameters, or hatchling parameters were observed. Significant decreases in mean serum phosphorous, serum total protein, albumin, bilirubin, and calcium concentrations were observed in high-dose-group females; no differences were noted among males. Eggshell strength and thickness in the high-dose group were significantly reduced compared to controls. Trends toward increased liver weights and decreased spleen weights were observed in WEVC-treated birds. Applications of WEVC to developing eggs showed it to be less toxic than unweathered North Slope crude oil. Doses covering up to one-third of the shell area of developing mallard eggs (92 mg) resulted in no effects on developing embryos. Eggs treated with the control material, petrolatum, were adversely affected by applications covering approximately one-sixth of the eggshell (24 mg), suggesting inhibition of gas exchange. Neither material affected hatchling survival or growth.
Steady-state model of biota sediment accumulation factor for metals in two marine bivalves
Authors: Thomann Robert V. , Mahony John D. , Mueller Rosemarie 
Published: March 2010

Abstract
A model of the biota sediment accumulation factor (BSAF) is developed to relate the ratio of metal concentrations in two marine bivalves (Crassostrea virginica and Mytilus edulis) to sediment metal concentration. A generalized metal BSAF can be approximated by a simple relationship that is a function of sediment to water column partitioning, the bioconcentration factor (BCF), the depuration rate, the metal assimilation efficiency from food, the bivalve feeding rate, and the growth rate. Analyses of “Mussel Watch” data indicate that the median BSAF across stations varies by about three orders of magnitude from Zn, Cd, and Cu at the highest levels of BSAF = 1 to 10, while Cr has the lowest BSAF at 0.01. Total Hg is about 1.0 and Ni and Pb are approximately 0.1. Calibration of the model indicates that the food route of metal accumulation is significant for all metals but especially for Zn, Cd, Cu, and Hg where virtually all of the observed BSAF is calculated to be due to ingestion of metal from food in the overlying water. These results indicate a potential significance of the metal-binding protein metallothionein, which results in relatively high binding of metal and resulting low depuration rates.
Pilot scale validation of the river/fish bioaccumulation modeling program for nonpolar hydrophobic organic compounds using the model compounds 2,3,7,8-TCDD and 2,3,7,8-TCDF
Authors: Abbott Joan D. , Hinton Steven W. , Borton Dennis L. 
Published: March 2010

AbstractThe interactive and user-friendly PC-computer-based RIVER/FISH mechanistic modeling procedure was evaluated and found to provide credible simulations of aquatic organism bioaccumulation for nonpolar hydrophobic organic chemicals (NPHOCs) using a four-trophic-level food web calculation methodology. Model evaluation included calibration to observations of tetrachlorinated dibenzodioxin and -furan (TCDD/F) bioaccumulation in largemouth bass (Micropterus salmoides) and channel catfish (Ictalurus punctatus) that were exposed in pilot-scale experimental streams receiving biologically treated pulp mill effluent and subsequent comparison of model predictions without bioaccumulation parameter adjustment (validation) to similar but independently obtained bioaccumulation observations. When calibrated with site-specific information on NPHOC loading rates and organism feeding habits, model prediction uncertainty was within U.S. Environmental Protection Agency (EPA) established standards averaging 1.1 pg/g for the observations used for model validation, which all measured &lt; 20 pg/g. The procedure appears suitable for field-scale applications provided the site-specific feeding habits of each organism in the simulated food web can be estimated accurately, all significant chemical loadings are quantified, and the natural variability of bioaccumulation processes is considered when interpreting simulation results.
Metabolism of different PCB congeners in plant cell cultures
Authors: Wilken Annelen , Bock Claudia , Bokern Maria , Harms Hans 
Published: March 2010

Abstract
The metabolism of 10 different congeners of polychlorinated biphenyls (PCBs) was tested in cell cultures of 12 different plant species. The rate of metabolism was determined through comparison with cells inactivated by treatment with perchloric acid. The metabolism of defined PCB congeners was strongly dependent on the plant species. In particular, two Fabaceae species exhibited high capacities for metabolizing different congeners. Except for PCB 15 (4,4′-dichlorobiphenyl), it was shown that a lower chlorination grade is associated with higher metabolism rates. Also, it was shown that substitution and molecular configuration play an important role in the metabolism of PCBs in plants. In studies with 14C-PCB 1 (2-chlorobiphenyl) in soybean cultures, one dihydroxylated and six different monohydroxylated compounds were detected after acid hydrolysis of polar metabolites (conjugates). Hydrolysis of metabolites of 14C-PCB 52 (2,2′,5,5′-tetrachlorobiphenyl) in wheat cell cultures yielded four monohydroxylated and three dihydroxylated metabolites.
Survey of nine organotin compounds in the netherlands using the zebra mussel (Dreissena Polymorpha) as biomonitor
Authors: Stäb Joan A. , Frenay Michel , Freriks Ivo L. , Cofino Wim P. , Th. Brinkman Udo A. 
Published: March 2010

Abstract
In the present survey zebra mussels were used as biomonitors to evaluate concentrations of nine organotin compounds (OTs) in Dutch fresh waters. To this end mussels were sampled at 56 locations throughout the country at the end of the summer of 1992. Variations in OT concentrations in zebra mussels were studied at two locations near potato crops that were sprayed with triphenyltin (TPT) in order to estimate the integration period over which body concentrations reflect the environmental quality. Apparent depuration half-life times in the field were calculated to be 100 to 200 d for TPT, which indicates that body burdens represent the TPT water quality over a long period of time. Results from the survey showed that OTs are still ubiquitously present in the freshwater environment in The Netherlands. Despite the implementation of legislation restricting the use of tributyltin (TBT), very high TBT body concentrations can still be found. The TPT was found in very high concentrations in mussels near sources of this fungicide. It was also discovered at remote locations. Possibly the presence of TPT there is due to transport via the air. The degradation products of TBT and TPT, the di- and mono-, -butyl- and -phenyltins, were also detected in nearly all mussels analyzed. Tricyclohexyltin (TCT) and fenbutatinoxide (FBTO), which are much less used organotin pesticides, were identified only in a few cases and do not appear to pose real environmental threats. Statistical analysis by means of principal component analysis was found to be a useful tool for evaluating the sources of OTs monitored by the zebra mussels.
A method to buffer the concentrations of free Zn and Cd ions using a cation exchange resin in bacterial toxicity studies
Authors: Knight Bruce , McGrath Steve P. 
Published: March 2010

Abstract
The chemical form or species of metal present in a growth system is crucial to the toxicity of that metal. A growth medium is described in which the free metal concentration of either Zn or Cd is known. A method using a cation exchange resin as a buffer to maintain free metal ion concentrations during microbial growth is discussed. Using a buffered system, free concentrations of 3.4 μg Cd L−1 and 57 μg Zn L−1 reduced the growth rate of a sensitive isolate of Rhizobium leguminosarum biovar trifolii. The results demonstrate that to assess the true toxicity of Cd and Zn, the free ion concentration must be considered and that small free concentrations must be buffered.
Lead and cadmium in wild birds in southeastern spain
Authors: Garcia-Fernandez Antonio Juan , Sanchez-Garcia Jose Antonio , Jimenez-Montalban Pedro , Luna Aurelio 
Published: March 2010

Abstract
The main purpose of this study was to monitor exposure to lead and cadmium in wild birds in Murcia, a southeastern region of Spain on the Mediterranean coast. This region lies on one of the African-European flyways. Samples of liver, kidney, brain, bone, and whole blood from several species of wild birds were obtained during 1993. We found a clear relationship between cadmium and lead concentrations in birds and their feedings habits. Vultures (Gyps fulvus) had the highest concentrations of lead (mean 40 μg/dl in blood), and seagulls (Larus argentatus and Larus ridibundus) the highest concentrations of cadmium (mean 4.43 μg/g in kidney). Insectivores had high concentrations of both metals, and diurnal and nocturnal raptors showed the lowest tissue concentrations. The finding that tissue and blood concentrations were generally not elevated suggests environmental (rather than acute) exposure. Birds from more industrialized areas of the region studied here had higher concentrations of both lead and cadmium.
Quantum chemical approach to estimate physicochemical compound properties: Application to substituted benzenes
Authors: Schüürmann Gerrit 
Published: March 2010

Abstract
Estimation models for Henry's law constant (H), water solubility (Sw), vapor pressure (Pv), and octanol/water partition coefficient (Kow) of nonelectrolytes are derived from basic thermodynamic equations. The resultant regression equations require only two molecular descriptors, which are available from chemical structure through semiempirical quantum chemical calculations: free energy of solvation (δGs), and molecular contact surface area (CSA). Results are presented for a set of 17 benzenes with experimental data taken from literature, yielding squared correlation coefficients r2adj (adjusted for degrees of freedom) between 0.83 and 0.95. The discussion includes limitations from currently available continuum solvation models to calculate δGs, aspects of potential error compensation, and the suitability of this approach to understand macroscopic compound properties in terms of calculated quantities that represent distinct types of intermolecular interactions.
Short Communication: A comparison of the toxicity of 30 reference chemicals to Daphnia Magna and Daphnia Pulex
Authors: Lilius Henrik , Hästbacka Tom , Isomaa Boris 
Published: March 2010

Abstract
To determine whether significant differences exist in the sensitivity of different Daphnia species to toxicants, the acute toxicity of the first 30 MEIC (multicenter evaluation of in vitro cytotoxicity) reference chemicals was determined in two species of Daphnia: D. magna and D. pulex. Correlation and regression analysis of the EC50 data for immobilization showed a very good concordance (r = 0.97, slope = 1.02). A comparison between the EC50 data obtained for D. magna by two laboratories independently for the 50 MEIC chemicals also showed a good concordance (r = 0.93, slope = 0.91). In both comparisons the regression line did not differ significantly from the regression line for a 1:1 regression. We conclude that our study, including a set of reference chemicals, indicates there is no difference in the overall sensitivity of the two Daphnia species and the two clones of D. magna.
Physiological, reproductive and pathological effects of dietary bleached pulp mill effluent on mink (Mustela Vison)
Authors: Smits Judit E.G. , Wobeser Gary A. , Schiefer Bruno H. 
Published: March 2010

Abstract
In this study mink (Mustela vison) were exposed to whole bleached-kraft mill effluent (BKME) through their diets. The investigation examined clinical, biochemical, induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity, one-generational reproductive, and pathological effects on mink exposed to BKME through water containing 25% effluent, and diet containing 75% (pilot and first subchronic study) fish caught downstream of the BKME discharge point of the pulp mill. In a 6-week pilot study, no adverse effects were found on behavioral, gross pathological, histopathological, hematological, or biochemical variables tested. In an 8-month exposure study, no significant effects on these parameters, or on gestation, kit birth weight, kit survival, libido, estrus, sperm quality, or hormone levels were found. This was followed by a second 8-month study using double the number of mink (30 BKME-exposed, 30 controls), and modified dietary formulations. Whole fish was decreased to 45%, and 15% softwood-run BKME was added to the food. In this study, the liver somatic index was greater in exposed males (p = 0.068) than in control males. Hepatic EROD activity was 1.8 times greater in exposed female (p = 0.0001) and 2.0 times greater in exposed male (p = 0.0004) mink compared with controls.
Acute and chronic toxicity of ammonium nitrate fertilizer to amphibians from southern ontario
Authors: Hecnar Stephen Joseph 
Published: March 2010

Abstract
Increasing nitrate levels in surface and ground waters are of global concern. Effects of nitrates on human health are well documented, but effects on amphibians have received little attention. I exposed Bufo americanus (American toad), Pseudacris triseriata (chorus frog), Rana pipiens (leopard frog), and Rana clamitans (green frog) tadpoles to ammonium nitrate fertilizer in water. In acute tests, mortality varied among species (96-h LC50; 13.6-39.3 mg/L NO3-N) and significant weight loss occurred. In chronic tests (100 d; 0, 2.5, 5, 10 mg/L NO3-N) chorus frog and leopard frog tadpoles had significantly lower survivorship in the 10-mg/L treatments, but green frog survivorship was not affected. Number of chorus frogs metamorphosing was significantly lower in the 10-mg/L treatment, but development time was not affected. In acute exposures, reduced activity, weight loss, and physical abnormalities were observed. Toxic effects of ammonium nitrate occurred in all four species at concentrations that are commonly exceeded in agricultural areas globally. Nitrate fertilizers may play a role in the apparent global amphibian decline.
Avian exposure to organophosphorus and carbamate pesticides on a coastal South Carolina golf course
Authors: Rainwater Thomas R. , Leopold Vincent A. , Hooper Michael J. , Kendall Ronald J. 
Published: March 2010

Abstract
A field study was conducted to examine avian exposure to organophosphorus (OP) and carbamate (CA) pesticides applied to turf on a coastal South Carolina golf course. The number, distribution, and activity of birds on turfgrass were monitored from May 25 to August 27, 1993. Over 1,600 birds representing 23 species were counted on turfgrass during designated monitoring sessions and incidental observations. Most birds were observed during morning hours, on fairways, and on the back nine holes of the course. Foraging was the predominant behavior observed. Blood samples and footwashes were collected from red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and boat-tailed grackles (Quiscalus major) for measurement of plasma cholinesterase (ChE) activity and chemical residues, respectively. Reactivation of plasma ChE in 22 blood samples suggested CA exposure, but no overt signs of anti-ChE poisoning were observed in birds sampled. However, an incapacitated laughing gull discovered after an application of the CA bendiocarb (3.36 kg/ha) exhibited 87% depression of plasma ChE and displayed symptoms consistent with OP/CA intoxication. Pesticide exposure was confirmed by recovery of 50.33 μg bendiocarb in the footwash. Mole crickets (Scapteriscus spp.) that surfaced following the same chemical application contained bendiocarb residues and may have been ingested by foraging birds. Results of this study suggest a potential for avian exposure to OP and CA pesticides on the golf course, but few actual exposures and acute effects were observed.
Application of toxicity identification procedures to the echinoderm fertilization assay to identify toxicity in a municipal effluent
Authors: Bailey Howard C. , Miller Jeffrey L. , Miller Michael J. , Dhaliwai Bhupindar S. 
Published: March 2010

Abstract
Toxicity was detected in a municipal effluent with the echinoderm fertilization assay. Dendraster excentricus appeared more sensitive to the effluent than did Strongylocentrotus purpuratus. A Phase 1 toxicity identification evaluation (TIE) was conducted using procedures adapted to the echinoderm fertilization bioassay. The Phase 1 TIE implicated cationic metals as the cause of toxicity, and follow-up investigations suggested that copper was the primary cation responsible. As part of the TIE, bioassays were conducted on ammonia and several cations. No-observable-effect concentrations for D. excentricus were ≥ 13.4 μg/L (Ag), ≥9.4 μg/L (Cd), 3.8 to 13.1 μg/L (Cu), ≥0.7 μg/L (Hg), and 10 mg/L (N, as total ammonia). The data also suggested that interspecific differences in sensitivity to copper and ammonia exist between Dendraster excentricus and Strongylocentrotus purpuratus.
A residue-based toxicokinetic model for pulse-exposure toxicity in aquatic systems
Authors: Hickie Brendan E. , McCarty Lynn S. , Dixon George D. 
Published: March 2010

AbstractThis pulse-exposure model (PULSETOX) is based on the simple one-compartment first-order kinetics (1CFOK) equation. It tracks the accumulation of waterborne organic chemicals by fish and predicts acute toxicity by means of previously established relationships between whole-body residues and lethality. The predictive capabilities of the model were tested with a data set of 27 acute pulse-exposure lethality tests with larval fathead minnows (Pimephales promelas) exposed to pentachlorophenol (PCP). Tests included eight single exposures (2 to 96 h) and 19 multiple exposures, which varied in the number (2 to 15) and duration (2 to 24 h) of pulses, and time interval between pulses (6 to 24 h). Experimental work included determination of 1CFOK kinetics parameters from [14C]PCP uptake and clearance, and from time-toxicity curves. Lethality was expected in any exposure regime where the fish reaches or exceeds the critical body residue (CBR) of 0.30 mmol PCP/kg fish (sd, ±0.02; n = 11). Using the CBR endpoint, the model accounted for between 90 and 93% of variability in the observed lethality data, depending on the toxicokinetic parameters employed. Predictive power of the model was optimized by using kinetics parameters derived from the toxicity curve for pulse-toxicity tests as shown by the regression: predicted LC50 = 1.04±(observed LC50) + 0.01 (p &lt; 0.001, r2 = 0.94, n = 27).