bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytotoxicity of floodplain soils contaminated with trace metals along the Clark Fork River, Grant-Kohrs Ranch National Historic Site, Deer Lodge, Montana, USA
Authors: Rader Brian R , Nimmo Del Wayne R , Chapman Phillip L 
Published: March 2010

Abstract
Concentrations of metals in sediments and soils deposited along the floodplain of the Clark Fork River, within the Grant–Kohrs Ranch National Historic Site, Deer Lodge, Montana, USA, have exceeded maximum background concentrations in the United States for most metals tested. As a result of mining and smelting activities, portions of the Deer Lodge Valley, including the Grant–Kohrs Ranch, have received National Priority List Designation under the Comprehensive Environmental Response, Compensation and Liability Act. Using a series of plant germination tests, pH measurements, and metal analyses, this study investigated the toxicity of soils from floodplain “slicken” areas, bare spots devoid of vegetation, along the Clark Fork River. The slicken soils collected from the Grant–Kohrs Ranch were toxic to all four plant species tested. The most sensitive endpoint in the germination tests was root length and the least sensitive was emergence. Considering emergence, the most sensitive species was the resident grass species Agrostis gigantea. The sensitivities were reversed when root lengths were examined, with Echinochloa crusgalli showing the greatest sensitivity. Both elevated concentrations of metals and low pH were necessary to produce an acutely phytotoxic response in laboratory seed germination tests using slicken soils. Moreover, pH values on the Grant–Kohrs Ranch appear to be a better predictor of acutely phytotoxic conditions than total metal levels.
Comparison of azinphosmethyl toxicity to juvenile red drum (Sciaenops ocellatus) and the mummichog (Fundulus heteroclitus)
Authors: Van Dolah Robert F , Maier Philip P , Fulton Michael H , Scott Geoffrey I 
Published: March 2010

Abstract
The acute and sublethal responses of juvenile red drum (Sciaenops ocellatus) and mummichogs (Fundulus heteroclitus) were evaluated to determine the relative effects of exposure to azinphosmethyl (APM). Acute responses were based on 96-h static-renewal bioassays at salinities of 5 and 20‰. Sublethal responses were based on inhibition of brain acetylcholinesterase (AChE) activity after 24-h exposures at each salinity and by measuring behavioral and stamina (swimming ability) responses of each species. The acute toxicity tests indicated that juvenile red drum were significantly more sensitive to APM than were mummichogs (mean lethal concentration [LC50] = 6.3–7.1 μg/L versus 65–84 μg/L). No significant differences were noted in the LC50 response of either species at reduced salinities. In contrast, mummichogs were more sensitive to APM-induced inhibition of brain AChE activity than juvenile red drum (mean effective concentration [EC50] &lt; 1.0 μg/L in mummichogs and &gt;5.0 μg/L in red drum). Behavioral response tests indicated that neither species avoided pesticide-laden water, which may increase their vulnerability to APM runoff. Stamina assays indicated that juvenile red drum experienced a decreased ability to swim after a 6-h exposure to 12 μg/L APM. Mummichogs were less sensitive with respect to the effects of APM on swimming ability at concentrations as high as 24 μg/L APM (p &lt; 0.1).
Bioaccumulation of polychlorinated dibenzo-p-dioxins in sediment by oligochaetes: Influence of exposure pathway and contact time
Authors: Loonen Hélène , Muir Derek C G , Parsons John R , Govers Harry A J 
Published: March 2010

AbstractOligochaetes (Lumbriculus variegatus) were exposed simultaneously to radiolabeled [3H]2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and [14C]octachlorodibenzo-p-dioxin (OCDD) in sediment for 28 d, in order to study accumulation processes of hydrophobic substances. Elimination was studied for a further 20 d. The uptake and elimination rate constants and the bioaccumulation factors (BAFs) were determined for TCDD and OCDD in the presence and absence of sediment (overlying water). Steady-state concentrations in oligochaetes were achieved for TCDD but not for OCDD over the 28-d exposure. Biota-sediment accumulation factors (BSAFs) after a 28-d exposure were 1.6 ± 0.27 for TCDD and 0.07 ± 0.02 for OCDD. Steady-state log BAF values (lipid based) for TCDD and OCDD in oligochaetes in the overlying water were 5.9 and 5.5 L/kg, respectively. The effect of incubation time between sediment and contaminants was investigated by repeating the accumulation study after a contact period of 21 months. BSAFs of sediment-sorbed TCDD and OCDD were 1.5 to 2-fold lower for the long contact time sediment. Based on comparison of predicted accumulation from pore water and observed accumulation by sediment-exposed oligochaetes, it was concluded that 1.4-fold greater accumulation occurred due to assimilation of TCDD and OCDD from ingested sediment. This additional accumulation in the presence of sediment, not accounted for by uptake only from pore waters, was consistent with literature data for other hydrophobic organochlorines.
Subchronic effects of five di-orthoPCB congeners on survival, growth and reproduction in the fathead minnowPimephales promelas
Authors: Suedel Burton C , Dillon Tom M , Benson William H 
Published: March 2010

AbstractThe effects of five di-ortho polychlorinated biphenyl (PCB) congeners (International Union of Pure and Applied Chemists numbers 52, 101, 138, 153, 180) on survival, growth, and reproduction in the fathead minnow, Pimephales promelas, were determined. Fish were exposed to one of two nominal concentrations (2.5 μg/L [low] and 25.0 μg/L [high]) of each congener for a total of 13 weeks (7-week prespawning period plus 6-week spawning period) under flow-through conditions using methanol as a carrier solvent. At termination, P. promelas survival was high (92.6–100%) in all PCB congener treatments. PCB congeners had no significant (p &lt; 0.05) sublethal effects on reproductive success within the concentration range examined. The total number of eggs, clutch size, number of clutches, percent hatchability, and presence of terata in offspring were not significantly affected. Reproductive success was slightly but not significantly enhanced in the solvent control and high (25 μg/L) treatment concentrations for congeners 52, 101, 138, and 153. Growth expressed as wet weight was not affected for both adult males or females. Male lengths were not significantly affected but female lengths were significantly reduced when exposed to congeners 101, 138, 153, and 180. Pimephales promelas accumulated substantial amounts of all PCBs, with tissue concentrations ranging from 13 to 183 mg/kg wet weight at termination in PCB-exposed fish. These tissue residues are one to several orders of magnitude greater than those reported for these congeners in aquatic biota previously collected in industrial waterways of the Great Lakes. Several di-ortho PCB congeners frequently found in aquatic biota showed minimal adverse effects on fathead minnow survival, growth, and reproduction even though bioaccumulation of these congeners was substantial.
2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in extracts of Baltic white-tailed sea eagles
Authors: Koistinen Janna , Koivusaari Juhani , Nuuja Ismo , Vuorinen Pekka J , Paasivirta Jaakko , Giesy John P 
Published: March 2010

Abstract
Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin-(TCDD) equivalents were measured in extracts of Baltic white-tailed sea eagle tissues. Extracts of salmon, ringed seal, and grey seal were analyzed as other predatory species of the same area. Concentrations in eagle and seal tissues were greater than those in salmon. Concentrations of TCDD equivalents (TCDD-EQs) determined by the H4IIE bioassay were compared with toxic equivalents (TEQs) derived from instrumental chemical analyses in fractions containing polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) or coplanar polychlorinated biphenyls (PCBs). Toxic equivalents were calculated by use of an additive model in which the product of the concentrations of instrumentally measured individual congeners were multiplied by their TCDD equivalency factors and were summed to give a total concentration of TEQs. The TCDD-EQs were compared with TEQs to develop a mass balance to determine whether all the TCDD-like activity was accounted for. For example, the concentration of TCDD-EQs in the coplanar PCB fraction of the most contaminated eagle was 980 pg/g fresh weight (fw), and that of the PCDD/PCDF fraction was 240 pg/g fw. The TEQs determined by chemical analyses for coplanar PCBs was 770 pg/g fw, and that of PCDD/PCDFs was 270 pg/g fw in this eagle. Thus, concentrations of TCDD-EQs were approx. 20% greater than those of TEQs. The true difference in activities is probably greater because of lower recoveries and infra-additivities among congeners in the bioassay. This indicates that there are compounds present in the extracts that can contribute to the total concentrations of TCDD-EQs that were not accounted for by TEQs. The hazard quotient, calculated as the ratio of current concentrations of TCDD-EQs in white-tailed sea eagle eggs to the no-observable-adverse-effect concentration, ranged from 7.3 to 141 (mean = 52.7, SD = 43). This indicates that current concentrations of TCDD-EQs in these eggs are likely causing adverse effects in the Baltic populations of white-tailed sea eagles. This study indicated that the H4IIE bioassay is useful for monitoring the presence and biological activity of TCDD-like compounds in environmental samples like white-tailed sea eagles.
Evaluation of a first-order model for the prediction of the bioaccumulation of PCBS and DDT from sediment into the marine deposit-feeding clamMacoma nasuta
Authors: Boese Bruce L , Lee Henry , Echols Scott 
Published: March 2010

AbstractA first-order model for predicting contaminant bioaccumulation from sediments into benthic invertebrates was validated using a marine deposit-feeding clam, Macoma nasuta, exposed to polychlorobiphenyl (PCB)-spiked and dichlorodiphenyltrichloroethane (DDT)-contaminated sediments. Contaminant uptake and depuration were analyzed following short-term and long-term sediment exposures. Uptake and depuration rates were used to predict steady-state bioaccumulation factors (BAFs) and exposure times needed to attain steady state. These predictions were compared to observed steady-state BAFs. Estimating elimination and uptake rates from depuration and short-term uptake experiments was an accurate means of predicting BAFs for some PCBs (log octanol-water partition coefficient, Kow, &lt;7) but was not as accurate for predicting DDT BAFs. The exposure time need to attain steady state was poorly predicted by the model. The results demonstrated that a standard 28-d bioaccumulation test estimated steady-state tissue residues within two-fold and was a better predictor than the model for the BAFs of superlipophilic PCBs (log Kow &gt;7). Differences in contaminant bioavailability were noted between field-contaminated (DDT) and laboratory-spiked (PCB) sediments.
Estimating inhibition concentrations for different response scales using generalized linear models
Authors: Bailer A John , Oris James T 
Published: March 2010

Abstract
Legal mandates exist for the protection of aquatic life and human health from the impacts of toxins released into receiving waters. To accomplish this objective, numeric environmental quality criteria are set. Data utilized commonly in the development of such criteria include no-observed-effect concentrations (NOECs), lowest-observed-effect concentrations (LOECs) and effective concentrations (ECs). The NOEC and LOEC are design-sensitive indices and are open to strong criticism. The EC indices are often estimated through the inversion of a fitted parametric regression model. One criticism leveled against the EC estimation routines has been that one model cannot be appropriate for the variety of different biological endpoints that are studied in aquatic toxicology. These biological endpoints include survival (dichotomous response), fecundity (counts), and biomass/growth (continuous response). In the present study, generalized linear models (GLiMs) are shown to provide a general model for data commonly encountered in aquatic toxicology. The proposed EC estimator, labeled a relative inhibition or RI estimator, is derived in this GLiM framework. This estimator represents the concentration, or more generally, the exposure level to some hazard, associated with a specified level of change in the response relative to the control response. Along with the construction of this estimator, standard errors and confidence intervals are presented. This RI estimator is then applied to dichotomous, count, and continuous responses to illustrate its use.
Initial sorption of aromatic amines to surface soils
Authors: Lee Linda S , Nyman Arto K , Li Hui , Nyman Marianne C , Jafvert Chad 
Published: March 2010

AbstractSorption of aniline, α-naphthylamine, and benzidine to three silty clay loams was measured from CaCl, electrolyte solutions in single and binary solute systems after a 1-d residence time. Soils varied in pH (4.4–7.2), cation-exchange capacity (CEC, 10–30 cmolc/kg), and organic carbon content (OC, 1–3%). Plots of sorbed amine concentrations versus aqueous amine concentrations exhibited nonlinearity in the concentration range investigated. Sorption increased with decreasing soil-solution pH for all solutes. Decreases in sorption with increasing CaCl2 concentrations were greatest at low pH. In binary solute experiments, α-naphthylamine depressed the sorption of aniline and this depression increased with decreasing pH. Normalizing sorption to the cation-exchange capacity of the protonated species compensated for most of the differences observed between soils at different pH values suggesting that cation exchange is the primary process occurring during initial contact times. In selected experiments, sorbed aromatic amines were extracted from soils with different solvents after a 1-d incubation. At low initial concentrations (&lt;0.01 mM) only a few percent of each amine was extractable; whereas 85% to 98% was recoverable at higher initial concentrations (1 mM). Although initial sorption appears to be to cation-exchange sites, the inability to recover all of the sorbed amine suggests early covalent bond formation on highly reactive sites and/or sorption to high-energy sites on clays or other soil constituents.
An automated HPLC method for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans in fish tissue on a porous graphitic carbon column
Authors: Echols Kathy , Gale Robert , Tillitt Donald , Schwartz Ted , O'Laughlin Jerome 
Published: March 2010

Abstract
The Ah (aryl-hydrocarbon) hydroxylase-receptor active polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were fractionated by an automated high-performance liquid chromatography (HPLC) system using the Hypercarb™ porous graphitic carbon (PGC) column. This commercially available column was used to fractionate the di-, mono-, and non-ortho PCBs into three fractions for gas chromatography (GC)/electron capture detection analysis, and a fourth fraction containing the PCDDs/PCDFs for GC/mass spectrometry analysis. The recoveries of the PCBs ranged from 68 to 96%, and recoveries of the PCDDs/PCDFs ranged from 74 to 123%. The PGC column has the advantage of faster separations (110 min versus 446 min) and less solvent use (275 ml versus 1,100 ml) compared with automated fractionation of these compounds on activated carbon (PX-21), while still affording good separation of the classes. The PGC column may have an advantage over the pyrenyl-based HPLC method because it has a greater loading capacity (400 μg total PCBs versus 250 μg). Overall, the PGC is a standard column that provides reproducible fractionation of PCDD/PCDFs and PCBs for analytical measurement in environmental samples.
A review of concurrent ambient water column and sediment toxicity testing in the Chesapeake Bay watershed: 1990–1994
Authors: Hall Lenwood W , Alden Raymond W 
Published: March 2010

Abstract
The objectives of this study were to identify toxic ambient areas in the Chesapeake Bay watershed by using a battery of water column and sediment toxicity tests. Twenty-five ambient stations in nine river/harbors were tested during 1990 through 1994. Seasonal and annual comparisons were conducted at selected stations. Inorganic and organic contaminants were evaluated in ambient water and sediment concurrently with water column and sediment tests to assess possible causes of toxicity, although absolute causality cannot be established. Multivariate statistical analysis was used to develop a TOX-INDEX at each station for both water column and sediment toxicity data. Water column tests from the 5-year testing period showed that 43% of the time, some degree of toxicity was reported. The most toxic sites based on water column results were located in urbanized areas such as the Elizabeth River, Baltimore Harbor, and the Middle River. Water quality criteria for copper, lead, mercury, nickel, and zinc were exceeded at one or more of these sites. Some degree of sediment toxicity was reported from 70% of the tests conducted during the 5-year period. The Elizabeth River and Baltimore Harbor stations were reported as the most toxic areas based on sediment results. Sediment toxicity guidelines (Long and Morgan effects range median [ER-M] values) were exceeded for one or more of the following metals at these two locations: arsenic, cadmium, chromium, copper, lead, nickel, and zinc. At the Elizabeth River stations 9 of 16 semivolatile organics and 2 of 7 pesticides measured exceeded the ER-M values. Various semivolatile organics exceeded the ER-M values at a number of Baltimore Harbor sites; pyrene and dibenzo (a,h) anthracene were particularly high at one of the stations (Northwest Harbor).
The influence of worm age, duration of exposure and endpoint selection on bioassay sensitivity for Neanthes arenaceodentata (Annelida: Polychaeta)
Authors: Bridges Todd S , Farrar J Daniel 
Published: March 2010

Abstract
The influence of worm age, duration of exposure, and endpoint selection on bioassay sensitivity were evaluated for Neanthes arenaceodentata. Worms were exposed to contaminated sediment collected from Black Rock Harbor (BRH) near Bridgeport, Connecticut, USA. This sediment was diluted with clean control sediment to result in five experimental treatments: 0, 25, 50, 75, and 100% BRH. Three exposure scenarios were employed: (1) a 4-week exposure beginning with newly emerged juveniles (EJ–4w), (2) a 7-week exposure beginning with newly emerged juveniles (EJ–7w), and (3) a 4-week exposure beginning with 3-week-old juveniles (3WO–4w). Six measures of worm size were recorded at the conclusion of each exposure to evaluate differences among measurement endpoints. Survival was significantly reduced at the 25% BRH level for the EJ–7w scenario and at the 100% BRH level for the EJ–4w and 3WO–4w scenarios. Growth was significantly reduced at the 25% BRH level in each exposure scenario. Estimates based on the calculated minimum detectable difference indicated that considerably lower concentrations of BRH (6–10%) should be distinguishable by measuring effects on Neanthes growth. Worm size measured in terms of projected area, dry weight, and ash-free dry weight provided the most sensitive measures of effects. Increasing the length of exposure from 4 to 7 weeks and initiating exposures with emergent juveniles rather than 3-week-old worms increased the sensitivity of the bioassay. The results of this study demonstrate that N. arenaceodentata is sensitive to the presence of sediment-associated contaminants and that test animal age, duration of exposure, and choice of endpoint can have a large effect on the magnitude of the toxic response observed.
Functional responses inLeptoxis praerosato increasing metal concentration and exposure duration
Authors: Reed-Judkins Donna K , Farris Jerry L , Cherry Donald S , Heath Alan G , Cairns John 
Published: March 2010

AbstractThe protectiveness of USEPA ambient water quality criteria for copper (Cu) and zinc (Zn) was tested using the snail Leptoxis praerosa in short- and long-term artificial stream tests. Acute criteria were tested in 96-h survival tests. Chronic criteria were tested by comparing cellulolytic enzyme activity impairment, bioconcentration, and survival in 14-, 20-, 30-, and 114-d exposures. Significant Cu bioconcentration occurred within 40 d at the chronic Cu criteria concentration, followed by significant cellulolytic enzyme activity impairment within 54 d. Significant bioconcentration and enzyme activity impairment occurred within 40 and 54 d, respectively, at the chronic Zn criteria concentration, but survival was much higher than in Cu-exposed snails. Approximate additive effects were seen in combination treatments of Cu and Zn. Similar patterns of effects were seen from both increased exposure duration and concentration. This research concluded that criteria based on abbreviated chronic tests may be underprotective for some sensitive taxa when exposures are prolonged.
In vivo testing of the functional integrity of the corticosterone-producing axis in mudpuppy (amphibia) exposed to chlorinated hydrocarbons in the wild
Authors: Gendron Andrée D , Bishop Christine A , Fortin Réjean , Hontela Alice 
Published: March 2010

AbstractThe functional integrity of the hypothalamo–pituitary–interrenal (HPI) axis was tested in an aquatic salamander, the mudpuppy (Necturus maculosus), exposed in the wild to HPI axis disrupters. The response to stress challenges was compared in mudpuppies sampled at nine sites of the St. Lawrence and Ottawa rivers during winter. Polychlorinated biphenyls and organochlorine pesticides measured in gonads indicated that the exposure was highly variable among sites. Females subjected to a standardized capture and confinement stress, a treatment that induces a surge of circulating corticosterone, had significantly lower levels of corticosterone at a number of contaminated sites compared to animals from the reference areas. Among-site differences could not be distinguished in males that had very low corticosterone levels overall. The reduced corticosterone response at contaminated sites was not associated with an atrophy of the interrenal corticosterone-releasing cells. A corticotrophin (adrenocorticotrophic hormone, ACTH) challenge imposed in situ after a 24-h postcapture recovery elicited a corticosterone surge significantly lower in contaminated females and males, pointing to disruptions along the HPI axis downstream of the pituitary ACTH-secreting cells. Corticosterone levels measured after recovery were higher at the contaminated site, suggesting an increase in resting levels. Liver glycogen, whose replenishment is partly mediated by corticosterone, was significantly depleted in salamanders collected at most contaminated sites. Our results suggest xenobiotic-induced disruptions within the HPI axis of an amphibian species, but the role of alternative factors is also discussed.