bluuebunny/crossref_metadata_2025_split huggingface dataset:
Second-round interlaboratory comparison of hepatic ethoxyresorufin-O-deethylase activity in white sucker (Catostomus commersoni) exposed to bleached-kraft pulp mill effluent
Authors: van den Heuvel Michael R. , Dixon D. George , Munkittrick Kelly R. , Stegeman John J. 
Published: March 2010

AbstractLivers were collected from six male and six female white sucker (Catostomus commersoni) at both a bleached-kraft pulp mill effluent (BKME)-exposed site and a reference site during the 1992 spring spawning migration. A semistandardized methodology for 7-ethoxyresorufin-O-deethylase (EROD) analysis was proposed that featured similar physical and chemical conditions yet allowed for different instrumentation and techniques. Postmitochondrial supernatants (PMSs) were analyzed for EROD activity by 14 laboratories, and repeat EROD analyses were performed within one laboratory to estimate within-laboratory variability. All laboratories found significantly higher levels of EROD activity (approximately threefold) in males from the BKME-exposed site; only 5 of 14 laboratories found significantly higher levels in exposed females. Data from three labs were dropped from the analysis because of outlying values. The mean coefficient of variation (C.V.) for the remaining 11 laboratories was 34.7%, which was not significantly different from the C.V. determined for six analyses by one technician (28.4%). The mean C.V. for five analysts within one laboratory was significantly lower (16.4%) than either of the former values. There was no difference in absolute values or the variability of microplate and conventional EROD assay data. Analysis of Bradford and Lowry protein data showed that both assays have low variability (C.V.s = 16.8 and 17.4%, respectively); these two techniques produced very similar estimates of protein content. Immunochemical analysis demonstrated a significant correlation existed among microsomal P4501A concentration and EROD activity. Sources of commercially available resorufin standard were tested, and the mean molar extinction coefficient was 54.0 ± 1.1 cm−1 mM−1.
[3H]-2,3,7,8-TCDD uptake and elimination kinetics of medaka (Oryzias latipes)
Authors: Schmieder Patricia , Lothenbach Douglas , Tietge Joseph , Erickson Russell , Johnson Rodney 
Published: March 2010

AbstractUptake and elimination rate constants for [3H]-2,3,7,8-tetrachlorodibenzo-p-dioxin ([3H]TCDD) were estimated by exposing medaka (Oryzias latipes) to [3H]TCDD in flowing water with no solvent carriers. Uptake was determined from body burdens measured on exposure days 0, 2, 4, 6, 10, and 12. Elimination was quantified from whole fish after 28, 90, and 175 d in uncontaminated water. Medaka accumulated [3H]TCDD at a rapid rate, achieving residues 24,000 times the water concentration after 12 d, with no indication of approach to steady state. After 6 months in uncontaminated water, the pg TCDD/g decreased by 69%, much of the decrease due to growth dilution as evidenced by only a 47% decrease in the pg TCDD/fish. Uptake and elimination rate constants (2,300 ml/g/d and 0.0045/d, respectively) were estimated by fitting a one-compartment, linear, mass-balance model to the data, adjusting for growth rate. The experimental design, including solvent-free delivery of [3H]TCDD, exposure at concentrations below maximum water solubility, and measurement of fish growth and lipid content during a 6-month elimination phase, resulted in a predicted steady-state bioconcentration factor (BCF) for medaka of 510,000, a number considerably higher than previously reported for dioxin BCFs. Kinetic parameters were used to successfully predict TCDD BCF in medaka exposed independently.
Air monitoring in the arctic: Results for selected persistent organic pollutants for 1992
Authors: Fellin Phil , Dougherty Donna , Barrie Len A. , Toom Desiree , Muir Derek , Grift Norbert , Lockhart Lylie , Billeck Brian 
Published: March 2010

Abstract
The Arctic is generally considered to be a pristine environment and has few direct inputs of organochlorine compounds (OCs), including pesticides, herbicides, polychlorinated biphenyls, or polycyclic aromatic hydrocarbons (PAHs). In spite of this, airborne concentrations of persistent organic pollutants (POPs) are comparable to those in more populated and industrialized regions of North America and Europe. Atmospheric transport and condensation of compounds at low temperature conditions are important factors contributing to the presence of contaminants in the Arctic. A long-term program has been established to measure the airborne concentrations of POPs in the Arctic. The first station at Alert was established in January 1992. The concentrations measured in the first year of monitoring for 18 compounds that are representative of different compound classes are presented. Seasonal variations for PAHs are similar to those for Arctic haze and peak during winter. For example, in the coldest period, October to April, benzo[a]pyrene concentrations were found to average 20 pg/m3, whereas, in contrast, during the relatively warm May to September period, average levels were 1.0 pg/m3. For OCs, the seasonal cycle was not as pronounced as that for PAH compounds. For example, α-hexachlo-rocyclohexane was found at Alert at average concentrations of 62 and 57 pg/m3, respectively, during cold and warm periods. It is postulated that air concentrations are influenced by advection from distant source regions as well as exchange with local (Arctic Ocean) surfaces.
Quality control considerations for the determination of acid-volatile sulfide and simultaneously extracted metals in sediments
Authors: Brumbaugh William G. , Arms Jesse W. 
Published: March 2010

Abstract
The determination of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) in sediment by treatment with dilute HCl shows promise as a tool for predicting the potential for metal toxicity to sediment-dwelling organisms. Effective quality control measures must be developed if this method is to become a reliable procedure and to ensure comparability of data. However, establishing quality control measures that assess procedural errors for an operationally defined method can be problematic. For example, preextraction spikes added for assessing the accuracy of AVS and SEMs may be poorly recovered due to adsorption or reaction with sediment constituents. For a variety of sediment types, we found preextraction spikes of sulfide, mercury, and copper to be prone to variable recoveries for the AVS/SEM procedure; recoveries averaged 76.3% (SD, 20.9) for sulfide, 61.9% (39.6) for Hg, and 90.1% (12.7) for Cu. The average recovery was near 100% for preextraction spikes of sediments for Cd, Ni, Pb, and Zn, and the recoveries of preextraction blank spikes for all analytes were consistently 95 to 105%. Binding of Cu or Hg with sulfides is sufficiently strong that 1 N hydrochloric acid will not necessarily keep the spiked metal in the dissolved state. This does not mean that the SEM procedure is invalid for these metals, only that the quality control of procedural error is difficult to assess. However, Hg will generally not be detected when measured as an SEM because of its tendency to adsorb onto sulfide minerals even at extremely low pH. Some reference sediments may be useful for assessing consistency of AVS determinations; we measured 5.97 ± 0.65 μmol/g in National Institute of Standards and Technology (NIST) 1645 and 1.34 ± 0.14 μmol/g in NIST 2704 for repeated determinations conducted over the past 3 years. Apparently, some sediments may contain an oxidation-resistant sulfide component that can release low to moderate AVS when treated with dilute HCl.
Monitoring exposure of nestling songbirds to agricultural application of an organophosphorus insecticide using cholinesterase activity
Authors: McInnes Pamela F. , Andersen David E. , Hoff Dale J. , Hooper Michael J. , Kinkel Linda L. 
Published: March 2010

Abstract
In June 1992 we collected 53 blood plasma samples from nestling red-winged blackbirds (Agelaius phoeniceus), house sparrows (Passer domesticus), and brown-headed cowbirds (Molothrus ater) at five study sites in northwestern Minnesota to evaluate the feasibility of using plasma and brain cholinesterase (ChE) activity and reactivation as a means of assessing exposure of nontarget organisms to the operational use of ChE- inhibiting insecticides in an agricultural setting. Three sites were adjacent to sugar beet fields that were likely to be treated with chlorpyrifos as Lorsban® (an organophosphorus [OP] insecticide) for control of sugar beet root maggot (Tetanops myopaeformis), and two sites were distant from fields likely to be treated (reference sites). Application of chlorpyrifos in fields surrounding study plots was monitored through contact with landowners and direct observations. Cholinesterase activity levels (total cholinesterase [ChE], acetylcholinesterase [AChE], and butyrylcholinesterase [BChE]) in nestling plasma were measured and tested for reactivation (ChE and AChE) in the presence of 2–PAM, an indication of exposure to an organophosphorus insecticide. In addition, 11 nestlings were euthanatized and in these samples we measured brain ChE activity and reactivation, and we analyzed gastrointestinal tracts and carcass washes for chlorpyrifos residues. Total ChE and BChE activity were lowest in similar-aged nestlings at sites adjacent to treated beet fields (ChE, t = −2.51, d.f. = 21, p = 0.033; BChE, t = −2.56, d.f. = 21, p = 0.043). Nestlings from sites that were near fields where chlorpyrifos was applied were more likely to exhibit plasma AChE reactivation than nestlings from reference sites where OP or carbamate insecticide application was improbable (x2 = 3.805, d.f. = 1, p ∼ 0.05). The magnitude of plasma ChE reactivation was highest within 1 to 3 d of insecticide application, although significant reactivation was measured up to 11 d after application of chlorpyrifos. Plasma AChE reactivation in the presence of pyridine-2–aldoxime methochloride (2–PAM) appeared to be a more sensitive indicator of exposure to chlorpyrifos than plasma ChE or BChE activity levels.
The community conditioning hypothesis and its application to environmental toxicology
Authors: Matthews Robin A. , Landis Wayne G. , Matthews Geoffrey B. 
Published: March 2010

Abstract
In this paper we present the community conditioning hypothesis, “ecological communities retain information about events in their history.” This hypothesis, which was derived from the concept of nonequilibrium community ecology, was developed as a framework for understanding the persistence of dose-related responses in multispecies toxicity tests. We present data from three standardized aquatic microcosm (SAM) toxicity tests using the water-soluble fractions from turbine fuels (Jet-A, JP- 4, and JP-8). In all three tests, the toxicants depressed the Daphnia populations for several weeks, which resulted in algal blooms in the dosed microcosms due to lower predation rates. These effects were short-lived, and by the second and third months of the experiments, the Daphnia populations appeared to have recovered. However, multivariate analysis of the data revealed dose/response differences that reappeared during the later part of the tests, often due to differences in other consumers (rotifers, ostracods, ciliates), or algae that are not normally consumed (filamentous green algae and bluegreen “algae”). Our findings are consistent with ecological theories that describe communities as the unique product of their etiologies. The implications of this to environmental toxicology are that almost all environmental events leave lasting effects, whether or not we have observed them.
Coal and deodorizer residues in marine sediments—contaminants or pollutants?
Authors: Chapman Peter M. , Downie James , Maynard Allan , Taylor Laura A. 
Published: March 2010

AbstractSediment studies around the diffuser of a relatively untreated major marine municipal sewage discharge indicated that 1,4-dichlorobenzene (1,4-DCB) and polycyclic aromatic hydrocarbons (PAHs) were among the contaminants of concern. Subsequent investigations revealed that elevated PAH concentrations were due to the shipwreck of a collier in the 1890s and were apparently not bioavailable. Coal is a common contaminant in marine and freshwater sediments and may be responsible, in some cases, for high PAH contaminant concentrations not resulting in pollution (i.e., biological effects) and can also affect total organic carbon measurements and normalizations. Little information exists regarding 1,4-DCB, whose main source to sewage appears to be toilet block deodorizers and which appears to be a useful marker of the extent of contamination for untreated sewage discharges. Correlative analyses suggest it is a pollutant, but this remains to be confirmed by experimental testing.
Dissociation constants of chloroguaiacols in water: A comparison of measured and predicted values
Authors: Gundersen Jennifer L. , MacIntyre William G. 
Published: March 2010

Abstract
Chloroguaiacols are common components of bleached-kraft pulp mill effluent known to bioaccumulate in aquatic organisms and to sorb on particulate material and sediments. Ionization properties of the chloroguaiacols must be known in order to explain their sorptive behavior in aquatic systems. To obtain this information, thermodynamic acid dissociation constants (pKa) of guaiacol (o-methoxyphenol) and nine chloroguaiacols have been determined by spectrophotometric methods. These experimental pKa values have been compared with literature values, values predicted by the Hammett equation, and predictions by quantum chemical calculations using MOPAC 6.0 with AM1 and MNDO Hamiltonian operators. Experimental and predicted acidities were strongly correlated, and the correlation equations obtained have been used to calculate pKa values for those chloroguaiacols that were unavailable for experimental measurement.
Effects of selected reducing agents on microbiologically mediated reductive dechlorination of aroclor® 1242
Authors: McCue Joseph J. , Gauger Kennedy W. , Holsen Thomas H. , Kelly Robert L. , Cha Daniel K. 
Published: March 2010

Abstract
The effect of various chemical reducing agents on the anaerobic microbial reductive biotransformation of polychlorinated biphenyls (PCBs) was investigated using Aroclor® 1242 at a concentration of 600 μg/g soil and microorganisms eluted from Hudson River sediments. The investigation sought to determine how various reducing agents influenced PCB dechlorination rates, patterns, and acclimation periods. Three reducing agents were incorporated into culture media: amorphous ferrous sulfide, sodium sulfide with sodium thioglycollate, and sodium sulfide with amorphous ferrous sulfide. All cultures were incubated statically under methanogenic conditions and ambient incubation temperatures of about 20°C. Cultures utilizing both sodium sulfide and ferrous sulfide together demonstrated the most extensive removal of meta- and para-chlorines, the highest average dechlorination rate, the greatest dechlorination of tri- and tetrachlorinated biphenyls, and the greatest accumulation of dichlorobiphenyl homologues. Overall, treatments incorporating ferrous sulfide, alone or in combination with sodium sulfide, demonstrated the ability to more effectively dechlorinate tri-ortho-substituted tetrachlorobiphenyls and pentachlorobiphenyls which had commonly positioned chlorines. Under these same conditions, dichlorobiphenyls, which are more amenable to aerobic dechlorination conditions, increased from 25% (molar basis) initially to levels greater than 60%.
Toxicity assessment of water from lakes and wetlands receiving irrigation drain water
Authors: Dickerson Kimberly K. , Hubert Wayne A. , Bergman Harold L. 
Published: March 2010

AbstractA method for reconnaissance-level assessments of the potential toxicity of water in lakes and wetlands that receive irrigation drain water is needed. We evaluated a model that predicts toxicity to aquatic organisms due to major ionic composition as a primary means of assessing water quality. The model was used in conjunction with acute toxicity tests and trace element analyses. Mortality of Ceriodaphnia dubia and fathead minnows (Pimephales promelas) observed in acute toxicity tests was compared to mortality predicted by the model. The method was applied at 22 lakes and wetlands on federally administered lands in Colorado, Montana, Utah, and Wyoming. Fourteen of 22 locations had water that was not toxic to test organisms. Six locations had undiluted water that was toxic to C. dubia due to major ionic composition, and two locations had undiluted water that showed toxic effects caused by factors other than elevated levels of major ions. The model for C. dubia seemed to be sufficiently accurate for future application using our approach to assess lakes and wetlands receiving irrigation drain water.
Toxicity, silver accumulation and metallothionein induction in freshwater rainbow trout during exposure to different silver salts
Authors: Hogstrand Christer , Galvez Fernando , Wood Chris M. 
Published: March 2010

AbstractStatic-renewal 168-h toxicity tests of silver nitrate (AgNO3), silver chloride (AgCln), and silver thiosulfate (Ag(S2O3)n) with juvenile rainbow trout (Oncorhyncus mykiss) were performed by standard methods. Because of low solubility of AgCl(s), bioassays for AgCln were performed in two separate ways. In one test series, AgCl(s) was added to freshwater and in another, AgCln(aq) was generated by adding AgNO3 to freshwater supplemented with 50 mM NaCl. Concentrations of Ag and metallothionein (MT) were analyzed in gills and livers offish that survived the exposures. Although Ag added as AgNO3 was found to be highly toxic to rainbow trout (168-h LC50 = 9.1 μg Ag L−1), the toxicities of the other Ag salts were low. The 168-h LC50 for Ag(S2O3)n was 137,000 μg Ag L−1 and no mortality was observed in AgCln (100,000 μg Ag L−1). Exposure to AgNO3, Ag(S2O3)n, or AgCln caused accumulation of Ag and induction of MT. Highest Ag levels were found in livers of trout exposed to 164,000 μg Ag L−1 as Ag(S2O3)n. In these fish, the hepatic Ag concentration was increased 335 times from the control value. The MT levels in gills and liver increased with the water Ag concentration and the highest level of MT was found in liver of fish exposed to Ag(S2O3)n.
Effects of boron and selenium on mallard reproduction and duckling growth and survival
Authors: Stanley Thomas R. , Smith Gregory J. , Hoffman David J. , Heinz Gary H. , Rosscoe Roger 
Published: March 2010

Abstract
Boron (B) and selenium (Se) sometimes occur together in high concentrations in the environment and can accumulate in plants and invertebrates consumed by waterfowl. One hundred twenty-six pairs of breeding mallards (Anas platyrhynchos) were fed diets supplemented with B (as boric acid) at 0, 450, or 900 ppm, in combination with Se (as seleno-DL-methionine) at 0, 3.5, or 7 ppm, in a replicated factorial experiment. Ducklings produced received the same treatment combination as their parents. Boron and Se accumulated in adult liver, egg, and duckling liver. In adults, B and Se caused weight loss, and B decreased hemoglobin concentration, egg weight, and egg fertility. Both B and Se reduced hatching success and duckling weight, and B reduced duckling growth and duckling production, and caused several alterations in duckling liver biochemistry. Duckling survival was not reduced by B or Se, and neither B nor Se had histopathologic effects on adult or duckling liver, kidney, or spleen. There was little evidence of interaction between B and Se. This study demonstrated that B and Se, in the chemical forms and at the dietary levels administered in this study, can adversely affect mallard reproduction and duckling growth.
Small mammal populations in maryland meadows during four years of herbicide (brominal®) applications
Authors: Clark Donald R. , Moulton Cynthia A. , Hines James E. , Hoffman David J. 
Published: March 2010

Abstract
The herbicide Brominal® was applied at the recommended rate to one plot in each of three paired 0.6-ha plots; the other three plots were used as controls. Plots were sprayed once in the fall of 1988 and 1989 and twice in the spring of 1990 and 1991. Small mammals were trapped three times during each activity season (April-October) to obtain population estimates before and after spraying and in the spring preceding fall spraying or the fall following spring spraying. Population estimates immediately after spraying gave no evidence of direct mortality. By 1991, dicot vegetation on treated plots was suppressed and mean numbers of meadow voles (Microtus pennsylvanicus) were less than on control plots. Because meadow voles favor dicots over monocots in their diet, reduced availability of dicots may have been related to the smaller vole population estimates. Species diversity of small mammals was negatively correlated with size of vole populations, but was not different between treated and control plots. Brominal apparently induced opaque corneas in nine voles. The condition was found in two voles too small to have been conceived at the time of the last previous spray nearly 8 months earlier, suggesting exposure to residue alone.
A comparison of β-adrenoceptors and muscarinic cholinergic receptors in tissues of brown bullhead catfish (Ameiurus nebulosus) from the black river and old woman creek, Ohio
Authors: Steevens Jeffery A. , Baumann Paul C. , Jones Susan B. 
Published: March 2010

Abstract
β-Adrenoceptors (βARs) and muscarinic cholinergic receptors were measured in brain, gill, and heart tissues of brown bullhead catfish exposed to polycyclic aromatic hydrocarbons in the Black River, Ohio, USA, and were compared to values from Old Woman Creek, Ohio, a reference site. A decreased number of βARs were found in the gill from Black River fish, possibly indicating a compensatory response subsequent to chemical stress.
Evaluation of PCB and hexachlorobenzene biota-sediment accumulation factors based on ingested sediment in a deposit-feeding clam
Authors: Boese Bruce L. , Lee Ii Henry , Specht David T. , Randall Robert , Pelletier Judith 
Published: March 2010

Abstract
Contaminated sediment exposure experiments were conducted using a marine deposit-feeding clam (Macoma nasuta) to determine biota-sediment accumulation factors (BSAFs) based on ingested sediment and fecal organic carbon. Internal, or gut, BSAFs were determined for hexachlorobenzene and 13 polychlorinated biphenyl congeners and were compared to those found with the standard method of calculating BSAFs, which uses the organic carbon and contaminant concentration of the whole or external sediment. The results of these experiments indicated that gut BSAFs were consistently smaller and less variable across sediment types than the corresponding standard BSAFs. Although these results indicate that using ingested sediment concentrations and fecal total organic carbon to calculate gut BSAFs might improve the predictive ability of the standard BSAF model, the benefit is small when compared to the difficulty in measuring the contaminant concentration on ingested sediment and the organic carbon content of feces.