bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of naphthalene on the hemolymph ion concentrations of Chironomus attenuatus and the possible mode of action
Authors: Harmon H. James , Sanborn Mark R. , Darville Roy G. , Wilhm Jerry L. 
Published: March 2010

Abstract
Naphthalene, a polycyclic aromatic hydrocarbon (PAH), was examined for its effect on the ionic regulation of the freshwater dipteran Chironomus attenuatus. Exposure of the fourth instar larvae to 1 mg/L naphthalene for 1 h resulted in elevated hemolymph Na+, K+ and Cl− concentrations.
After documenting the loss of ionic regulation in Chironomus exposed to naphthalene, we designed several experiments to elucidate the mode of action of naphthalene and other PAH (naphthol, phenanthrene, chrysene) on ionic regulation. Lipid vesicles were used to simulate biological membranes to test if PAH cause a loss of structural membrane integrity. Cellular membrane transport is mediated by the Na+, K+-ATPase enzyme system. Inhibition of this system was tested using cultured mammalian cells (HEp-2), which have a ouabain-sensitive Na+, K+-ATPase.
Ion leakage experiments using Na+, K+ and cytochrome c-loaded liposomes resulted in little ionic leakage, suggesting that PAH do not cause a loss of membrane integrity. Exposure of plasma membranes of cultured cells to PAH (10 mg/L) for 30 min caused inhibition of ouabain-sensitive Na+, K+-ATPase. Data indicated that as the molecular size of the PAH increased, the inhibition decreased. Thus, our data support the hypothesis that loss of ionic regulation in aquatic organisms is due to inhibition of specific enzyme systems and not to a general alteration of membrane integrity.
Effects of temperature and nutritional state on the acute toxicity of acridine to the calanoid copepod, Diaptomus clavipes schacht
Authors: Cooney John D. , Beauchamp J. , Gehrs Carl W. 
Published: March 2010

Abstract
Acute toxicity tests were performed on adult males and females of a freshwater calanoid copepod, Diaptomus clavipes Schacht, using the azaarene acridine as the test compound. Tests were performed at three temperatures (16, 21 and 26°C) and over a range of nutritional states (fed, starved and stock). Observations on mortality were made at 24-h intervals for 96 h.
Analysis of the data was based on comparisons (using different treatment combinations) of the parameters in a logistic survival function used to describe the mortality data. Median lethal concentrations (using 96-h LC50 values) were estimated from the logistic survival function as well as from the probit function, for comparative purposes. The LC50 values ranged from 1.64 to 6.70 mg/L, depending on temperature, nutritional state of the animals and sex. The LC50 values were highest for animals (fed before testing) at 16°C. As food availability decreased and temperature increased, toxicity of acridine increased up to fourfold. No significant differences in LC50 values were found between the sexes except in starved animals at 26°C, when males were more sensitive than females. This difference in toxicity between the sexes at 26°C may be due to differences in nutritional stress between the sexes (at this temperature), since control mortality at this temperature was also higher in males than in females.
Volatilization rates of selected haloforms from aqueous environments
Authors: Kaczmar Swiatoslav W. , D'Itri Frank M. , Zabik Matthew J. 
Published: March 2010

Abstract
Ratios of the gas transfer rate constants of oxygen to the haloforms CHC13, CHC12Br, CHC1Br2 and CHBr3 were measured and used to calculate an aqueous half-life range for each compound. The calculated half-lives suggest that production and release of haloforms as a result of chlorination of wastewater should not cause these materials to accumulate in the aquatic environment.
Acute toxicity of diazinon is similar for eight stocks of bobwhite
Authors: Hill Elwood F. , Camardese Michael B. , Heinz Gary H. , Spann James W. , Debevec Antonia B. 
Published: March 2010

Abstract
Nine-week-old bobwhite (Colinus virginianus) from eight different game farms were tested for their sensitivity to an acute oral exposure of technical-grade diazinon (phosphorothioic acid O,O-diethyl-O-[6-methyl-2-(l-methylethyl) -4-pyrimidinyl]ester). Extraneous variables associated with interlaboratory differences in husbandry were eliminated by incubating eggs and rearing chicks to test age for all stocks simultaneously in the same facilities at the Patuxent Wildlife Research Center. Under this single set of conditions, the responses of the eight stocks of bobwhite to diazinon were statistically inseparable, with LD50 values varying from 13 mg/kg (95% confidence interval, 8–21 mg/kg) to 17 mg/kg (95% confidence interval, 11–25 mg/kg). The pooled LD50 for the eight stocks was 14.7 mg/kg (95% confidence interval, 13.1–16.5 mg/kg).
An environmental hazard evaluation of uranium in a Rocky Mountain stream
Authors: Parkhurst Benjamin R. , Elder Robert G. , Meyer Joseph S. , Sanchez Deborah A. , Pennak Robert W. , Waller William T. 
Published: March 2010

Abstract
Uranium mining is an important industry in the Rocky Mountain region; however, little is known about the environmental hazards of uranium to fish and other aquatic organisms.
Indian Creek, a hard-water stream (200 mg/L as CaCO3) near Gunnison, Colorado, receives periodic discharges of runoff from a uranium mine. In addition, natural springs contribute uranium to the creek. As a result, uranium concentrations in the creek range up to 4 mg/L, concentrations which are potentially toxic to trout based on published toxicity data. Therefore, we conducted a series of studies to analyze the potential toxicity and bioaccumulation of uranium in Indian Creek and downstream waters.
A 60-d post-hatch, early life stage toxicity test was conducted with brook trout in water of hardness and alkalinity similar to Indian Creek. Additional tests were performed in soft and hard water (96-h acute toxicity tests) and in water of Indian Creek's quality (48-h acute toxicity tests). Trout from the 60-d test were also analyzed for uranium bioaccumulation. To confirm the results of the laboratory studies, these data were compared with on-site field study data, including surveys of fish and benthic invertebrates, and analyses of uranium levels in trout. The laboratory results indicated that the high hardness and alkalinity of the test water greatly reduced the potential toxicity of uranium to trout. Concentrations estimated to be chronically toxic from the early life stage test were greater than 9 mg/L; whereas the 48-h LC50 was 59 mg/L. Bioconcentration factors for uranium were low, ranging from 1.9 to 4.3.
Benthic invertebrate and fish studies conducted in Indian Creek confirmed that current uranium concentrations are not significantly toxic to resident aquatic biota. In-stream bioaccumulation of uranium is also very low, and is comparable to the laboratory-derived values.
Our study demonstrated that laboratory toxicity and bioaccumulation tests can accurately evaluate potential in-stream hazards of uranium. To accurately estimate in-stream toxicity and bioaccumulation of metals, it is important that laboratory tests simulate in-stream water quality.
Planimetric analysis of redear sunfish (Lepomis microlophus) hepatopancreas following selenium exposure
Authors: Sorensen Elsie M. B. , Bauer Thomas L. 
Published: March 2010

Abstract
A real ratios of pancreas cells to liver cells (P/L ratios) were determined planimetrically and compared with selenium accumulated in the hepatopancreas (liver and associated exocrine pancreas) of redear sunfish (Lepomis microlophus). Fish were collected from four locations in Martin Lake, Texas, and from a reference lake 8 km upstream in the same drainage system. Fish collected from selenium-contaminated areas in Martin Lake had significantly higher P/L ratios than did reference fish. The increase in the P/L ratios could be explained by either pancreatic cell hyperplasia or parenchymal hepatocyte necrosis and cell loss. Since a previous publication documented both central necrosis with loss of parenchymal hepatocytes and architectural disorganization and endoplasmic reticulum changes in the exocrine pancreas cells of these same redear sunfish, both changes probably occurred simultaneously. However, in this study, P/L ratios were not correlated with selenium levels in the hepatopancreas. This contrasts with published data regarding hematological changes, condition factors, and relative hepatopancreas weight for the same redear sunfish collected for this study. Relative ratios of pancreatic cells to liver cells determined in this study, therefore, were less accurate in pinpointing biological changes due to selenium than were the other parameters previously published using these same fish.
Laboratory sediment toxicity tests, sediment chemistry and distribution of benthic macroinvertebrates in sediments from the keweenaw waterway, michigan
Authors: Malueg K. W. , Schytema G. S. , Krawczy D. F. , Gakstatter J. H. 
Published: March 2010

Abstract
Acute laboratory sediment toxicity tests using the water flea Daphnia magna and the burrowing mayfly nymph Hexagenia limbata were conducted on sediments from two areas of the Keweenaw Waterway, Michigan, to determine whether the tests reflected the condition of benthic macroinvertebrate communities. The organisms were tested simultaneously in a recirculating bioassay chamber in which Daphnia were tested during the first two and last two days of a 10-d Hexagenia test. Sediment from the northern, copper-impacted portion of the waterway was generally acutely toxic to Daphnia, but not to Hexagenia, while sediment from the southern, less-impacted portion was not toxic to either organism. Positive relationships existed between organism mortality, copper content of the sediment and field distribution of macroinvertebrates.
Measurement of median lethal dose as a rapid indication of contaminant toxicity to fish
Authors: Hodson P. V. , Dixon D. G. , Kaiser K. L. E. 
Published: March 2010

Abstract
A new method was developed to rapidly measure the toxicity of contaminants to fish over 96 h. The method is the measurement of median lethal doses by intraperitoneal injection (IP-LD50). Contaminants are dissolved in 5% ethanol in saline or in cod-liver oil and injected at a rate of 1.0 ml per 100 g of fish.
The results of parallel bioassays to measure toxicity by oral intubation (OI-LD50) or aqueous exposure (LC50) were closely linked to IP-LD50 values. The coefficient of determination (r2) for a linear regression between IP-LD50 and OI-LD50 values was 0.99. In contrast, the r2 between IP-LD50 and LC50 values was lower (0.44) and the regression curvilinear. However, r2 improved to 0.82 when LD50 values were divided by the logarithm of the octanol-water partition coefficient (log P). Therefore, some of the differences in toxicity between chemicals may be due to interactions between their lipid (or water) solubilities and their rate of uptake by fish.
The IP-LD50 values of five chemicals varied with the carrier used; toxicity was lower for the oil carrier compared to injections with 5% ethanol in saline. The magnitude of the difference varied with the chemical tested, so that the two measures of toxicity did not appear to be related. However, the relationships again improved when the IP-LD50 (oil) was divided by log P.
The measurement of IP-LD50 values was faster, simpler and less expensive than traditional LC50 bioassays. The use of IP-LD50 values to screen chemicals for their relative toxicity to fish will save time and money without any real loss in the relevance of conclusions. We propose their use for research on environmental quantitative structure-activity relationships.
The acute toxicity of picloram, picloram potassium salt, and picloram triisopropanolamine salt to aquatic organisms
Authors: Mayes Monte A. , Dill D. C. 
Published: March 2010

Abstract
The toxicity of technical picloram acid (93.8% active ingredient), picloram potassium salt (43.5% active ingredient) and picloram triisopropanolamine salt (65.2% active ingredient) to aquatic organisms was evaluated in static acute toxicity tests. Species tested were the fathead minnow (Pimephales promelas Rafinesque), rainbow trout (Salmo gairdneri Richardson), bluegill (Lepomis macrochirus Rafinesque), and the daphnid (Daphnia magna Straus). The rainbow trout was the most sensitive species tested with 96-h LC50 values of 19.3, 48 and 51 mg/L for picloram acid, picloram potassium salt and picloram triisopropanolamine salt, respectively. These values are 36 × greater than the amount of picloram detected in freshwater streams following the application of picloram to experimental watersheds.
Rainbow trout bioconcentration of some halogenated aromatics from water at environmental concentrations
Authors: Oliver Barry G. , Niimi Arthur J. 
Published: March 2010

Abstract
The bioconcentration of 10 brominated and chlorinated aromatics by rainbow trout at ng/L concentrations, approaching environmental levels, has been studied. Seven of the compounds (3,4-dichlorobenzotrifluoride; 2,4,5-trichlorotoluene; 2,3,4-trichloroanisole; 1,4-dichloronapthalene; 1,3-dibromobenzene; 1,3,5-tribromobenzene; 1,2,4-tribromobenzene) reached a steady equilibrium concentration in the fish over the 90 day study period. Fish residue levels for the other three compounds (2,4-dichlorodiphenyl-ether; 1,2,4,5-tetrabromobenzene; 4,4′-dichlorobiphenyl) continued to increase over the entire study period. A good linear correlation (r2 = 0.79) between log bioconcentration factor (BCF) and log octanol-water partition coefficient (K) was found for the seven equilibrated compounds with a slope of 0.99. A good correlation between log BCF and parachor was also found for selected chemicals from this and an earlier study. Compounds that did not equilibrate plotted well below the log BCF versus log K line and had K values of &gt; 105 and parachors (surface tension corrected molar volumes) &gt; 400.
Toxicity of sediments from three metal-contaminated areas
Authors: Malueg K. W. , Schuytema G. S. , Gakstatter J. H. , Krawczyk D. F. 
Published: March 2010

Abstract
Sediments from Phillips Chain of Lakes (Wisconsin), Torch Lake (Michigan), and Little Grizzly Creek System (California) were tested for acute toxicity using the water flea, Daphnia magna, and the burrowing mayfly nymph, Hexagenia limbata. The organisms were tested simultaneously in a laboratory recirculating bioassay apparatus; Daphnia were tested during the first two (Daphnia I) and the last two (Daphnia II) days of 10-d Hexagenia tests.
Sediment from one of six sampling locations from the Phillips Chain of Lakes was toxic to Daphnia I, but not Daphnia II. None of these sediments was toxic to Hexagenia.
Contaminated sediments from Torch Lake and the Little Grizzly Creek System were highly toxic to Daphnia I and II, and Hexagenia.
In general, numbers of organisms, biomass, species diversity and dominant types of organisms correlated with metal content and acute laboratory toxicity.
Structure-activity relationship studies on the toxicities of benzene derivatives: I. An additivity model
Authors: Hall Lowell H. , Kier Lemont B. , Phipps Gary 
Published: March 2010

Abstract
A quantitative structure-activity analysis was performed on a series of substituted benzenes for which toxicity values have been obtained over 96 h in the fathead minnow. We have determined the additive contribution of several substituent groups. We have found a decreasing contribution to toxicity to be Cl &gt; Br &gt; NO2 &gt; CH3 &gt; OCH3 &gt; NH2 &gt; OH. This additivity model, expressed as an equation, yields a correlation coefficient (r) of 0.951, compared with the log of the lethal concentration (LC50). The positional dependence of substituents on benzene has been studied, as has the relationship between the substituent toxicity ranking and physical properties.
Organochlorine residues in eggs of black-crowned night herons from colorado and wyoming
Authors: McEwen Lowell C. , Stafford Charles J. , Hensler Gary L. 
Published: March 2010

Abstract
Eggs of black-crowned night-herons Nycticorax nycticorax (L.) were collected for analysis from seven nesting sites in Colorado and Wyoming in 1979. One egg was taken per nest from as many as 20 nests per site during early incubation. The nests were marked and revisited after hatching, but before fledging, to record the number of live young. DDE was detected in all of the collected eggs (total 147) at a mean concentration of 3.1 ppm, fresh basis (residue means are geometric). Mean DDE at the seven sites varied from 1.8 to 7.6 ppm. Polychlorinated biphenyls (PCBs) were detected in 81 eggs (mean 1.0 ppm); the highest mean at any site was 2.2 ppm. Twelve other organochlorines were each detected in 1 to 30 eggs, usually at a concentration of &gt; 1.0 ppm. Mean total organochlorines in the eggs from the seven sites ranged from 2.0 to 10.1 ppm and the median number of compounds per egg ranged from one to five. Eggshell thickness was negatively correlated (p &gt; 0.001, r = – 0.585) with DDE levels in the 147 eggs. Average shell thickness (0.258 ± 0.030 mm) was 8.8% lower than the average thickness (0.283 ± 0.016mm) of 40 pre-DDT eggs from this region. The nesting sites with the highest DDE and total organochlorine residues in the eggs had the thinnest shells, produced the fewest young and had more nonviable eggs and dead young. At four of the seven sites, the average number of live young per nest was &gt; 2.0, the minimum long-term mean required for population maintenance. The source of the contaminants found in the heron eggs in this study was not determined.
Toxicity of arsenite and arsenate to the marine macroalga Champia Parvula (rhodophyta)
Authors: Thursby Glen B. , Steele Richard L. 
Published: March 2010

Abstract
By a previously established test procedure that uses 4.5 μM phosphate in the medium, the marine red alga Champiaparvula (C. Agardh) Harvey was shown to be more sensitive to arsenite [As(III)] than to arsenate [As(V)]. Mature cystocarps (evidence of sexual reproduction) were formed when plants were exposed to 65 μg As(III)/L, but not when exposed to 95 μg As(III)/L. Three hundred micrograms As(III)/L was sufficient to kill C. parvula. Using the standardized test, plants grew just as well in 10,000 μg As(V)/L as they did in the controls; however, sexual reproduction did not occur at this concentration. Phosphate concentration up to 9.1 μM had little or no effect on As(III) toxicity. Arsenate toxicity, however, was inversely proportional to the amount of phosphate in the medium. In the absence of added phosphate, As(V) toxicity was similar to that of As(III), except plants were still alive at 1,076 μg As(V)/L (although they did not grow).
Behavioral effects of methyl parathion on social groups of bluegill (Lepomis macrochirus)
Authors: Henry Mary G. , Atchison Gary J. 
Published: March 2010

Abstract
The behavioral effects of three sublethal concentrations of methyl parathion on social groups of bluegill (Lepomis macrochirus) were examined. Consistently similar hierarchies were formed in all test groups, allowing for comparison both before and after toxicant administration. Significant increases in comfort movements and respiratory disruptions and decreases in aggressive behaviors were observed after methyl parathion was added to treatment tanks. Changes in the frequencies of the affected behaviors occurred primarily within the first 24 h of the treatment period. In every treatment, the most subordinate and dominant individuals were affected more pronouncedly than were intermediately ranked fish. Consequently, differential, contaminant-induced responses associated with rank should be considered when conducting bioassays and perhaps ultimately examined in the field when dealing with species which form social hierarchies. Examination of this factor could help clarify the relative roles of social stress and toxicant stress in producing an effect.
Field and laboratory evaluation of the influence of copper-diquat on apple snails in Southern Florida
Authors: Winger Parley V. , Imlay Marc J. , McMillan Wayne E. , Martin Thomas W. , Takekawa Jean , Johnson W. Waynon 
Published: March 2010

AbstractThe recent decline of apple snail (Pomacea paludosa) populations in canals surrounding Loxahatchee National Wildlife Refuge in southern Florida coincided with the use of copper-diquat for the control of the aquatic weed hydrilla (Hydrilla verticillata). Field and laboratory studies were designed to assess the effects of copper-diquat on apple snails, which are the primary food of the endangered snail kite Rostrhamus sociabilis (formerly known as the Everglade kite). Acute toxicities (96-h LC50 values) of Cutrine-Plus and Komeen (chelated formulations of copper) to immature apple snails were 22 and 24 μg/L, respectively. Diquat was toxic at a concentration of 1,800 μg/L and did not increase the toxicity of copper when the chemicals were used in combination. Evaluation of field samples indicated that copper concentrations were higher in detritus than in water, plants and mud, and that there was a gradient of copper concentration from the canal to the interior, the highest residues being in samples from the canal. Copper associated with detritus (up to 150 μg/g) had no effect on growth or survival of apple snails in field cage and tank studies. Also, field applications of copper-diquat to hydrilla had no effect on survival of caged adult and immature snails. Copper from field applications was rapidly taken out of solution by plants and organic material in the water and subsequently incorporated into the bottom detritus. Although the effects of repeated applications of copper-diquat and high body burdens of copper (accumulated during exposure to herbicidal treatment) on survival and reproduction of apple snails are not known, the information available indicates that treatment of hydrilla with copper-diquat was probably not responsible for the decline in the apple snail population. Application at recommended rates should pose no threat to these snails in the organically rich waters of southern Florida.
Toxicity of copper-spiked sediments to freshwater invertebrates
Authors: Cairns Michael A. , Nebeker Alan V. , Gakstatter Jack H. , Griffis William L. 
Published: March 2010

Abstract
Natural freshwater sediments from two Oregon sites were spiked with copper in the laboratory and two static toxicity tests were conducted with series of copper concentrations ranging from 59 to 10,600 mg/kg of dry sediment. Water (800 ml) was added to 1-liter test beakers over the sediment (200 ml) and repeatedly removed and replaced to lower the aqueous copper concentrations. When copper concentrations stabilized, i.e., attained equilibrium between water and sediment, the midge Chironomus tentans, the cladoceran Daphnia magna and the amphipods Hyalella azteca and Gammarus lacustris were introduced as test animals in solid-phase sediment toxicity bioassays. Based on dry-weight sediment copper concentrations, LC50 values (48-h for Daphnia, 10-d for other organisms) ranged from 681 to 2,296 mg/kg.
Effects of chronic exposure to coal-derived oil on freshwater ecosystems: I. Microcosms
Authors: Franco P. J. , Giddings J. M. , Herbes S. E. , Hook L. A. , Newbold J. D. , Roy W. K. , Southworth G. R. , Stewart A. J. 
Published: March 2010

Abstract
Sixteen 67-liter freshwater microcosms were treated for 8 weeks with an unrefined coal-oil in amounts ranging from 0.03 to 7 ml per week. Phenols make up 95% of the water-soluble compounds in this oil, and dissolved phenol concentrations averaged &lt;0.01 mg L−1 in the lowest dose and 10 mg L−1 in the highest. The microcosms were severely damaged at the highest treatment level; macrophytes, zooplankton and insects were eliminated, and the ecosystems became anaerobic. Microcosms did not recover to pretreatment conditions within 5 months. At lower dosages there were temporary effects on ecosystem metabolism, water chemistry and community structure. The most sensitive indices—community respiration, production/respiration ratio, pH and cladoceran zooplankton numbers—were affected at phenol concentrations below the lowest observable effect concentration of a chronic Daphnia magna bioassay.