bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute aquatic toxicity tests with acrylamide monomer and macroinvertebrates and fish
Authors: Krautter George R. , Mast Richard W. , Alexander Howard C. , Wolf Claude H. , Friedman Marvin A. , Koschier Francis J. , Thompson Carl M. 
Published: March 2010

Abstract
Aquatic toxicity tests were conducted to determine the acute toxicity of acrylamide monomer to two species of aquatic macroinvertebrates (48-h LC50) and three species of fish (96-h LC50). The test animals were daphnids (Daphnia magna), midges (Paratanytarsus parthenogenetica), rainbow trout (Salmo gairdneri), fathead minnows (Pimephales promelas) and bluegill (Lepomis macrochirus). The organisms were exposed to five concentrations of acrylamide and a control, using intermittent-flow procedures. The proportional diluter system was calibrated and the test system equilibrated before the tests were begun. Acrylamide monomer concentrations were analytically determined at equilibration, initiation and termination of the tests.
Macroinvertebrates and fishes were observed for mortality and abnormal behavior twice daily for the duration of the tests. The calculated LC50s, based on measured concentrations of acrylamide monomer, were as follows: daphnids, 160 mg/L; midges, 410 mg/L; rainbow trout, 110 mg/L; fathead minnows, 120 mg/L; bluegill, 100 mg/L. These values were three orders of magnitude higher than those concentrations previously reported to increase invertebrate mortality under field conditions. The results demonstrated that acrylamide monomer was moderately toxic to the five aquatic organisms studied, under the test conditions utilized.
Characterization of mixed-function oxidase systems of the nestling herring gull and its implications for bioeffects monitoring
Authors: Peakall D.B. , Norstrom R.J. , Rahimtula A.D. , Butler R.D. 
Published: March 2010

Abstract
The hepatic mixed-function oxidase system was characterized in embryonic and nestling herring gulls (Larus argentatus). The activity of aminopyrine N-demethylase decreased significantly with the age of the nestlings. No consistent changes in 7-ethyoxyresorufin O-deethylase, benzo[a]pyrene 3-hydroxylase or cytochrome P450 levels with age were found. Levels of organochlorines were determined in individual livers for the 21-d-old nestlings. Correlations among organochlorine residue levels were good, and the activities of aminopyrine N-demethylase and benzo[a]pyrene 3-hydroxylase correlated with each other and with cytochrome P450 levels. No correlations were found with 7-ethoxyresorufin O-deethylase activity, and none of the enzyme levels correlated with the organochlorine residue levels. However, cytochrome P450 levels correlated with both hexachlorobenzene and oxychlordane levels. The implications for the use of the mixed-function oxidase system for environmental monitoring of exposure to organochlorines and polynuclear aromatic hydrocarbons are discussed.
Characterization of effects of copper, cadmium and nickel on the growth of Nitrosomonas Europaea
Authors: Sato Chikashi , Schnoor Jerald L. , McDonald Donald B. 
Published: March 2010

Abstract
The effects of copper, cadmium and nickel on Nitrosomonas europaea were characterized by growth response. Copper inhibition caused a decrease in the growth rate of N. europaea that occurred immediately after inoculation. Cadmium inhibition caused a sharp decrease in the growth rate that occurred after a certain time period, yielding two distinctive growth rates. Nickel inhibition was characterized by an extended lag phase. The combined effects of copper and nickel affected both growth rate and lag. Combined effects of cadmium and nickel were also observed. The combined effect of nickel and copper was antagonistic with respect to both the growth rate and the lag period. Nickel and cadmium acted synergistically to depress the specific growth rate, but the combined effect was either antagonistic or additive (depending upon substrate concentration) with respect to duration of the lag.
Acute and chronic toxicity of ammonia to freshwater fish: A site-specific study
Authors: Mayes M. A. , Alexander H. C. , Hopkins D. L. , Latvaitis P. B. 
Published: March 2010

Abstract
The toxicity of ammonia to the juvenile stages of the bluegill (Lepomis macrochirus) and the walleye (Stizostedion vitreum), and to the embryo, larval and juvenile stages of the fathead minnow (Pimephales promelas) was determined in support of the development of a site-specific water quality standard for ammonia in the Tittabawassee River at Midland, Michigan. There was little difference among the acute toxicities of ammonia (expressed as un-ionized ammonia nitrogen NH3-N) to the three species tested, with 96-h LC50 values of 1.04, 1.06 and 1.50 mg NH3-N/L for the bluegill, walleye and fathead minnow, respectively. Evaluation of the chronic data showed no concentration-related effects for hatching success and growth. However, there was a significant (α = 0.05) decrease in number of normal larvae at hatch and in larval survival at 0.26 mg NH3-N/L and higher. The maximum acceptable toxicant concentration fell between 0.17 and 0.26 mg NH3-N/L, or 0.21 mg NH3-N/L when expressed as the geometric mean of these values. Both the acute and chronic values derived during this study are similar to those reported in the literature, indicating that, in this case, Tittabawassee River water quality did not influence the toxicity of ammonia to the species tested.
Determination and genotoxicity of nitrogen heterocycles in a sediment from the black river
Authors: West W. Raymond , Smith Philip A. , Booth Gary M. , Lee Milton L. 
Published: March 2010

Abstract
The genotoxicity of nitrogen heterocycles isolated from a sediment taken from the Black River near Loraine, Ohio, in an area that received effluents from the coking ovens of a steel plant was studied. These compounds were isolated by gel permeation chromatography and silicic acid adsorption chromatography from the moderately polar fraction of an organic extract of this sediment. Two complex mixtures of secondary and tertiary nitrogen heterocycles containing three to five aromatic rings were characterized using capillary column gas chromatography with selective detection. Both mixtures induced significant unscheduled DNA synthesis in primary rat hepatocytes and accounted for essentially all of the genotoxicity of the fraction from which they were isolated.
Comparative evaluation of three rapid marine toxicity tests: Sea urchin early embryo growth test, sea urchin sperm cell toxicity test and microtox
Authors: Nacci Diane , Jackim Eugene , Walsh Raymond 
Published: March 2010

Abstract
Three rapid marine toxicity tests were evaluated to determine their potential usefulness in a toxicity testing program: early embryo growth test and sperm cell toxicity test, both using the sea urchin Arbacia punctulata, and Microtox. Toxicity values (EC50s) were derived for eight organic chemicals and five metals using each system. Results were compared with LC50 values for the same chemicals from standard aquatic tests with Pimephales romelas and Daphnia magna and for the metals with Menidia menidia and Mysidopsis bahia. The EC50 values for the sea urchin early embryo growth test for organics and the LC50 values for fish and crustaceans for organics and metals with which the rapid tests were compared were from the literature.
For organic chemicals, EC50s from rapid tests closely approximated LC50s and toxicity rankings, except that the sperm cell test was particularly sensitive to 2,4-pentanedione and 2-methyl-2,4-pentanediol. EC50s for metals were generally comparable with each other and with other tests using embryo and sperm of other sea urchins and oysters but not with LC50s for Mysidopsis and Menidia.
These results indicate the potential value of rapid tests to screen and rank substances for toxicity. Additional information on the usefulness of these tests will be gained through continuing comparisons using a broad spectrum of single substances and complex mixtures with varying modes of action.
Impact of methoxychlor on freshwater communities of plankton in limnocorrals
Authors: Stephenson Gladys L. , Kaushik Narinder K. , Solomon Keith R. , Day Kristin 
Published: March 2010

Abstract
Aquatic enclosures, or limnocorrals (5 × 5 × 5 m deep), installed in a 10-ha mesotrophic lake in southern Ontario were used to evaluate the impact of four concentrations of methoxychlor (300 and 3 μg/L in 1981, and 50 and 5 μg/L in 1982) on plankton communities. Methoxychlor was acutely toxic at 300 μg/L to both the macrozooplankton (Cladocera and Copepoda) and microzooplankton (Rotifera). No recovery in macrozooplankton numbers was observed by the end of the experiment (119 d); however, densities of microzooplankton had recovered by 52 d to levels similar to those in control corrals. Changes in species composition of the microzooplankton community were such that the replicate corrals no longer contained similar rotifer populations.
Methoxychlor at 50 μg/L was toxic to all Cladocera, copepod nauplii and copepodites, and the Chlorophyta. Even at this concentration, numbers of Cladocera did not recover to levels similar to those in the control corrals by the end of the experiment (145 d); however, nauplii and copepodites recovered by 55 and 100 d, respectively. Numbers of Chlorophyta were significantly lowered by 50 μg methoxychlor/L (p %le; 0.05). The observed numerical recovery at 41 d was due primarily to an increase in the density of Kurchneriella lunaris. The biomass of this group remained low in these treated corrals because, despite its numerical increase, K. lunaris contributed little to chlorophyte biomass.
Although 5 μg methoxychlor/L was toxic only to Cladocera and copepodites, recovery occurred within 20 d. Methoxychlor at 3 μg/L had no observable effects on density of plankton or on community structure.
The responses to methoxychlor of the various groups of plankton generally appear to be exposure-dependent, with Cladocera and Chlorophyta exhibiting the greatest sensitivity.
Bioconcentration of hydrophobic chemicals in fish: Relationship with membrane permeation
Authors: Gobas Frank A. P. C. , Opperhuizen Antoon , Hutzinger Otto 
Published: March 2010

Abstract
A model is presented for the bioconcentration in fish of nonpolar hydrophobic chemicals that are not metabolized. The model assumes that diffusion rates through membrane-diffusion layer barriers influence uptake and depuration kinetics in fish. For extremely hydrophobic (log Kd, oct &gt; 3 to 4) chemicals, uptake rate constants in fish are independent of the solute's hydrophobicity, whereas for low to moderately hydrophobic chemicals proportionality between these parameters is observed. Additionally, elimination rate constants for low to moderately hydrophobic chemicals are independent of the solute's hydrophobicity. In contrast, the elimination rate constants for extremely hydrophobic chemicals, such as polychlorobenzenes and -naphthalenes, are inversely proportional to hydrophobicity. In the model presented, this is due to the rates of release from the lipid compartments of the fish. The general relationships between bioconcentration kinetic parameters and hydrophobicity are in agreement with experimental data.
Reproduction and health of mallards fed endrin
Authors: Spann James W. , Heinz Gary H. , Hulse Craig S. 
Published: March 2010

Abstract
Concentrations of 0, 1 and 3 ppm endrin in dry duck mash were fed to mallards (Anas platyrhynchos) starting in December, and health and reproduction were measured the following spring and summer. One male fed 3 ppm endrin died with 2.0 ppm endrin (wet weight), a diagnostically lethal level, in its brain. Birds fed 1 ppm endrin reproduced as well as, if not better than, controls. Birds fed 1 ppm endrin had significantly greater hatching success of fertile eggs than did those fed 0 or 3 ppm, and their clutches hatched significantly earlier than did those of birds fed 3 ppm. Mallards fed 3 ppm endrin appeared to reproduce more poorly than controls, but this finding must be regarded with caution because the results of statistical tests often were not significant. Endrin accumulated in eggs to a mean of 1.1 and 2.9 ppm (wet weight) when fed to hens at 1 and 3 ppm. The concentration of endrin in the carcasses of adults was similar to that in eggs, but the concentration in the fat of adults was about 4 to 7 times higher than in eggs.
Use of size-dependent mortality models to estimate reductions in fish populations resulting from toxicant exposure
Authors: Logan Dennis T. 
Published: March 2010

Abstract
In populations in which the rate of early mortality depends primarily on the size of individuals, growth and size become important determinants of population dynamics. Models based on size and developed for fish populations can provide a means of integrating acute and chronic toxicological observations to predict changes in population size. These models predict population reductions resulting from lethality to eggs and larvae, reduced growth rate, reduced length at hatch and any behavioral or physiological changes that increase either size-dependent or size-independent mortality rates. The dependence of mortality rate on size may arise from developmental changes, size-selective predation, changing energy balances or a combination of these. The biological source of mortality may dictate its mathematical expression. Since the size-dependent mortality modeled here may arise from several common sources, it may be widespread. As a result, reductions in natural populations caused by sublethal toxic exposures may not be unusual. These results suggest that measuring sublethal reductions in early growth that result from toxic conditions may be a meaningful way of estimating potential risks to natural populations.
Effects of copper, nickel and zinc on three species of oregon freshwater snails
Authors: Nebeker Alan V. , Stinchfield Ann , Savonen Carol , Chapman Gary A. 
Published: March 2010

Abstract
Three snail species collected from western Oregon were exposed to metals—Juga plicifera and Lithoglyphus virens, which inhabit cool coastal streams, and Physa gyrina, which is found in Willamette Valley ponds. J. plicifera were exposed in flow-through laboratory tests to copper and nickel, L. virens were exposed to copper, and P. gyrina were exposed to nickel and zinc. J. plicifera had a 96-h LC50 (50% of the test group died) of 0.015 mg/L for copper and a no observed effect level (NOEL, mortality not significantly different from that in control groups) of 0.006 mg/L (30-d survival). J. plicifera had a 96-h LC50 for nickel of 0.237 mg/L and a NOEL of 0.124 mg/L. L. virens had a 96-h LC50 for copper of 0.008 mg/L and a NOEL of less than 0.008 mg/L. P. gyrina had a 96-h LC50 for nickel of 0.239 mg/L, a 96-h LC50 for zinc of 1.274 mg/L and a NOEL for zinc of 0.570 mg/L.
Breaking strength: An alternative indicator of toxic effects on avian eggshell quality
Authors: Carlisle J. C. , Lamb D. W. , Toll P. A. 
Published: March 2010

Abstract
A method for measuring the breaking strength of avian eggshells is presented along with a brief review of the literature relating shell strength to chlorinated hydrocarbon exposure. The effect of dietary DDE on shell strength is compared with its effect on shell thickness in the mallard duck (Anas platyrhynchos L). Shell strength was significantly reduced at a lower dietary DDE concentration than was shell thickness. The potential utility of strength measurement as an end-point in toxicology studies is discussed.
DOWANOL, an environmentally safe adjuvant
Authors: Caux P.-Y. , Weinberger Pearl , Carlisle D. B. 
Published: March 2010

Abstract
Pesticide spray formulations include a variety of adjuvants as wetting agents, surfactants or emulsifiers. DOWANOL TPM (tripropylene glycol methyl ether) is one such adjuvant in current common use in spray formulations of the insecticide fenitrothion. Unlike some other adjuvants which we have tested, DOWANOL appears to have no significant toxicity for duckweed, Lemna minor L., an environmentally important aquatic plant, which has been previously shown to be sensitive to some formulations. Four parameters were monitored, namely, biomass, photosynthetic function, adenosine triphosphate level and changes in the electrical potential of the bathing media. Reported concentrations of DOWANOL in forest pools after spraying are of the order of 1 μg ml−1. We have tested concentrations up to 956 μg ml−1. The highest concentration produced significant functional impairment in the plants, which, however, recovered within 2 d in freshwater. Lower concentrations had no measurable effects. The threshold concentration for DOWANOL toxicity to Lemna is thus about three orders of magnitude higher than observed field concentrations, and we conclude that it therefore can be judged to be a relatively environmentally safe adjuvant.
Ring test of an embryo-larval toxicity test with zebrafish (brachydanio rerio) using chromium and zinc as toxicants
Authors: Dave Göran , Damgaard Birthe , Grande Magne , Martelin Jarl Erik , Rosander Björn , Viktor Tomas 
Published: March 2010

AbstractA protocol for determination of “no-effect” concentrations on hatch and survival in the zebrafish (Brachydanio rerio) has been evaluated at five laboratories for variability using chromium (K2Cr2O7) and zinc (ZnSO4 × 7H2O) as toxicants. Repeatability (r) and reproducibility (R), expressed as C.V. (coefficient of variation), for logarithmic median survival time ranged between 1% and 9% for r and between 1% and 29% for R depending upon concentration of toxicant. Variability increased at high concentrations, especially for zinc. For logarithmic median hatching time, C.V. for r ranged from 6% to 24% and for R between 11% and 27% for the various concentrations of chromium and zinc. Estimated logarithmic “no-effect” concentrations on survival of zinc and chromium had a C.V. for r below 10% and a C.V. for R below 15% for zinc and below 25% for chromium. Zinc delayed the time to hatch at lower concentrations than those that reduced survival time, for the estimated logarithmic “no-effect” concentrations of zinc on hatch r was around 75% and R around 100%. The “no-effect” concentrations based on all nine or ten tests from the five laboratories were 15 mg Cr/L and 0.5 mg Zn/L. Because of the cumulative toxicity of chromium in fish the chronic “safe” concentration may be considerably lower, but the “no-effect” concentration of 0.5 mg Zn/L for effects on hatching time is consistent with the chronic “safe” concentration found in other species of fish at the same hardness (100 mg/L expressed as CaCO3).
Avoidance responses of schooling fathead minnows (Pimephales promelas) to a blend of metals during a 9-month exposure
Authors: Hartwell S. Ian , Cherry Donald S. , Cairns John 
Published: March 2010

Abstract
Avoidance of a blend of four metals (relative proportions: 1.00 copper, 0.54 chromium, 1.85 arsenic, 0.38 selenium) was determined in fathead minnows (Pimephales promelas) in a steepgradient, laminar-flow chamber. Avoidance responses were determined seasonally during 12 months of laboratory observation for unexposed (control) and metals-exposed fish. Unexposed fish avoided very low concentrations of the blend (29 μg/L total metals). Fish exposed to 98 μg/L total metals preferred elevated concentrations equal to three times the holding exposure concentration (294 μg/L total metals) after 3 months of exposure, mildly avoided concentrations five times the holding exposure concentration (490 μg/L total metals) after 6 months of exposure and were not responsive to concentrations approaching ten times the holding exposure level (980 μg/L total metals) after 9 months of exposure. Activity, as measured by movements per unit time in the avoidance tests, was not affected by long-term exposure or during testing.
Field validation of avoidance of elevated metals by fathead minnows (Pimephales promelas) following in situ acclimation
Authors: Hartwell S. Ian , Cherry Donald S. , Cairns John 
Published: March 2010

Abstract
Avoidance of a blend of four metals (relative proportions: 1.00 copper, 0.54 chromium, 1.85 arsenic, 0.38 selenium) was determined in schools of fathead minnows (Pimephales promelas) in an artificial stream supplied with raw river water and in a natural stream. Control (unexposed) fish were tested in spring in the artificial stream and during summer in the artificial stream and a natural stream. Fish exposed continuously for 3 months to the blend of the four metals (98 μg/L total metals) in river water were tested during summer in the artificial and natural streams. Control fish avoided 71.1 and 34.3 μg/L total metals in the artificial stream in spring and summer, respectively, and 73.5 μg/L in the natural stream. Exposed fish did not respond to metals blends as high as 1,470 or 2,940 μg/L in the artificial and natural streams, respectively. Water hardness, turbidity and physical setting are implicated as possible causative factors in differences among control fish. Results are compared with those of previously reported laboratory studies and the effects of pollution observed in the New River, Virginia.
Relationships between aqueous oxygen concentration and uptake and elimination rates during bioconcentration of hydrophobic chemicals in fish
Authors: Opperhuizen Antoon , Schrap S. Marca 
Published: March 2010

Abstract
Oxygen concentrations in ambient water do not influence the uptake and elimination rates of 2,2′,5,5′-tetra- and 2,2′,4,4′,5,5′-hexachlorobiphenyl in guppies (Poecilia reticulata) after aqueous exposure. It is concluded that both the bioconcentration kinetics and bioconcentration factors are independent of the ambient oxygen regime between 2.5 and 8.0 mg/L.
Since it can be assumed that the volume of water passing over the gills increases proportionally with decreasing aqueous oxygen concentration, it is concluded that for the bioconcentration of extremely hydrophobic chemicals, such as polychlorinated biphenyls, the uptake efficiencies rather than the uptake rate constants are dependent on the aqueous oxygen concentration. The experimental results support the concept that the rate of diffusion of the hydrophobic chemicals inside the fish, and not the ventilation volume of contaminated water passing over the gills, dominates the rates of uptake and elimination.
A steady-state fugacity-based pharmacokinetic model with simultaneous multiple exposure routes
Authors: Paterson Sally , MacKay Donald 
Published: March 2010

Abstract
A physiologically based human pharmacokinetic model of chemical intake via ingestion of food and water and inhalation of air is presented. The model takes the form of a series of algebraic equations that describe the steady state, constant exposure, transport rates and physiological distribution in arterial and venous blood, lung, fat, skin, muscle, liver, gut tissue, gut lumen and richly perfused tissues. It is assembled using the fugacity concept and is applied to a hexachlorobiphenyl and styrene. It is suggested that the model can be used to elucidate how tissue concentrations respond to these intake routes and thus should contribute to better assessment of the hazards or effects of exposure to organic chemicals on humans and other mammals.