bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of methoxychlor on zooplankton in freshwater enclosures: Influence of enclosure size and number of applications
Authors: Solomon Keith R. , Stephenson Gladys L. , Kaushik Narinder K. 
Published: March 2010

Abstract
Methoxychlor was applied to 20, 100 and 1,000 m3 enclosures at a nominal concentration of 20 μg L−1. Total dissipation was more rapid than expected in the 20 m3 enclosures (slope = −0.0288) while rates in the 100 and 1,000 m3 enclosures were similar (slope = −0.0207 and −0.0187, respectively). Effects on zooplankton were less rapid and less severe and recovery more rapid in the 20 m3 than in the larger enclosures, but little difference was observed between the 100 and 1,000 m3 enclosures. Comparison of a single application of 20 μg L−1 in 100 m3 enclosures with two applications of 10 μg L−1, 35 days apart, also in 100 m3 enclosures, showed a more rapid dissipation after the first application than after the second (slope = −0.0236 vs. −0.0161). Acute toxic effects were not observed after the second treatment, and little effect on time to recovery was noted. Selection of certain species by the second application of methoxychlor was not observed.
Dietary absorption efficiencies and elimination rates of polycyclic aromatic hydrocarbons (PAHs) in rainbow trout (salmo gairdneri)
Authors: Niimi A. J. , Dookhran G. P. 
Published: March 2010

Abstract
Dietary absorption efficiencies and elimination rates of acenaphthylene, 1-phenyl naphthalene, 2-methyl anthracene, 9-methyl anthracene, triphenylene, perylene, benzo[b]fluorene, dibenzo[a,h]anthracene, benzo [ghi]perylene and coronene were examined in rainbow trout. Subadult fish were exposed to 10 mg of each chemical over 5 d and polycyclic aromatic hydrocarbon (PAH) levels were monitored during the following 25 d. The results indicated that PAHs were not accumulated by trout through dietary exposure because of the combined effects of poor absorption efficiencies and rapid elimination rates. Phenyl naphthalene was more persistent than the other PAHs examined, with a half-life of 25 d.
Adaptation to a quaternary ammonium surfactant by suspended microbial communities in a model stream
Authors: Shimp Robert J. , Schwab Burney S. , Larson Robert J. 
Published: March 2010

Abstract
The adaptation of suspended microbial communities to a quaternary ammonium surfactant, dodecyltrimethylammonium chloride (C-12TMAC), was studied in a model stream dosed with the surfactant. Water collected at several sites downstream of the introduction of C-12TMAC was tested for the ability of the suspended microbial community to biodegrade the surfactant and several naturally occurring chemicals. At the concentrations tested, C-12TMAC had no significant impact on the total size of the microbial community or its ability to degrade natural materials (glucose or amino acids). However, the ability of the community to degrade C-12TMAC increased by 10- to 1,000-fold during exposure at all locations downstream from the dose site. After prolonged exposure, the C-12TMAC-degrading microbial community also developed a resistance to “shock loads” of the surfactant (i.e., adaptation was maintained even when input concentrations were increased to levels that previously decreased biodegradation activity). Adaptation was a stable process as long as some quantity of C-12TMAC entered the stream. However, when input of surfactant was halted, the microbial community lost its ability to rapidly degrade the material. Upon redosing the stream with a low concentration of the chemical, the microbial community rapidly regained its enhanced biodegradative activity toward C-12TMAC. These results illustrate the importance of adaptation in determining the fate of synthetic chemicals in aquatic environments.
Fate of fenthion in salt-marsh environments: II. Transport and biodegradation in microcosms
Authors: O'Neill Ellen J. , Cripe Claude R. , Mueller Leonard H. , Connolly John P. , Pritchard Parmely H. 
Published: March 2010

Abstract
The fate of fenthion was examined in laboratory microcosms to describe interaction between sediment and biodegradation in the field. A mathematical model also was calibrated to calculate distribution of fenthion in microcosms. Intact sediment cores, with and without a salt-marsh plant, Juncus roemerianus (black needlerush), were placed in microcosm vessels to simulate an undisturbed sediment bed of a salt marsh and areas containing Juncus. In a formalin-sterilized microcosm without plants, fenthion disappeared exponentially from the water column with a half-life of 105.0 h. Fenthion had a half-life of 35.5 h in a nonsterile microcosm without plants. In the nonsterile microcosm with plants, the half-life was slightly shorter, 33.2 h. The sediment was fractionated into 0.5 cm layers. Fenthion was found at greater sediment depths in nonsterile systems than predicted by diffusion and sorption in the sterile microcosm, possibly because of bioturbation. Distribution of fenthion in sediment was not appreciably different between microcosms with and without plants. Fenthion appeared to be biodegraded in the upper (1 to 7 mm) sediment layers.
PCB congeners to monitor with caged juvenile fish in the upper Hudson river
Authors: Jones Peter A. , Sloan Ronald J. , Brown Mark P. 
Published: March 2010

Abstract
A distinct pattern of consistently most abundant PCB congeners is identified in caged juvenile fish during a developmental monitoring study of bioaccumulation in the upper Hudson River, 1985. An identical qualitative congener pattern is recognized in juvenile fish after 28-d exposures in the late spring, summer and fall, even though each period is characterized by a different temperature and flow regime in the river. The same congener pattern is evident after only 3 d of exposure and persists until at least 42 d. Due to their physicochemical properties, biological half-life in fish and site-specific abundance in the upper Hudson River sediments, 1 tri-CB, 13 tetra-CBs and 3 penta-CBs (3,4,4′; 2,2′,3,4′; 2,2′,3,5′; 2,2′,4,4′; 2,2′,4,5; 2,2′,4,5′; 2,2′,5,5′; 2,3,3′,6; 2,3,4,5; 2,3′,4,4′; 2,3′,4′,5; 2,3′,5′,6; 2,4,4′,6; 2′,3,4,5; 2,2′,3,5,6; 2,2′,3,5′,6; and 2,2′,4,6,6′) are the congeners to monitor over the short term.
Fate of naphthenic hydrocarbons in the bile of rainbow trout (Salmo gairdneri)
Authors: Hellou Jocelyne , Banoub Joseph H. , Ryan Anne 
Published: March 2010

Abstract
Rainbow trout (Salmo gairdneri) were exposed orally to n-butylcyclohexane and on the sixth day after ingestion, 3 to 5% of the dose of parent compound was recovered as a metabolite in the bile. The glucuronide of cis-3-n-butylcyclohexanol was identified as the single metabolic product. Exposure of trout to t-butylcyclohexane afforded the glucuronide of 4-t-butylcyclohexanol in a much smaller amount. Comparative studies between these two small naphthenic hydrocarbons and the corresponding aromatic molecules are also reported.
Consistent inhibition of peripheral cholinesterases by neurotoxins from the freshwater cyanobacteriumAnabaena flos-aquae: Studies of ducks, swine, mice and a steer
Authors: Cook W. O. , Beasley V. R. , Lovell R. A. , Dahlem A. M. , Hooser S. B. , Mahmood N. A. , Carmichael W. W. 
Published: March 2010

AbstractFreshwater algal blooms associated with outbreaks of sudden death in ducks and swine were examined for cholinesterase (ChE)-inhibiting toxins as the possible cause of death. In both investigations, Anabaena flos-aquae was identified as the predominant alga in the bloom material. In both cases, assays on tissues from mice dosed intraperitoneally with algal extracts revealed inhibition of ChE in whole blood, plasma, diaphragm and lung, but not in brain. With algae from the field case involving ducks, toxicosis was experimentally reproduced by oral intubation in ducks and swine, but not in mice and a steer. However, the steer, as with other species, was susceptible to toxicosis induced by parenteral administration of an algal extract. Assays on tissues from affected animals revealed inhibition of ChE in whole blood, plasma, red blood cells, diaphragm, lung and pectoral muscle, but not in brain or retina. In vitro electric eel (EC 3.1.1.7) ChE assays with HPLC-purified extracts of the same alga revealed direct inhibition of acetylcholinesterase. Clinical signs in all animals were compatible with muscarinic and nicotinic cholinergic stimulation. Death of exposed animals is an apparent result of peripheral ChE inhibition.
Human serum ddt levels related to consumption of fish from the coastal waters of los angeles
Authors: Gossett Richard , Wikholm Gary , Ljubenkov John , Steinman David 
Published: March 2010

Abstract
Fish from Los Angeles County coastal waters contain high concentrations of the banned pesticide DDT, its metabolites DDE and DDD, and polychlorinated biphenyls (PCBs). The most popular sportfish caught from piers in southern California (comprising 30% of the catch), white croaker (Genyonemus lineatus), contains total DDT levels above the Federal Drug Administration guideline (5 mg/kg wet weight) in edible tissue at 7.6 mg/kg wet weight total DDT.
We quantified blood serum levels of DDTs and PCBs in 16 subjects who consumed locally caught sportfish at least three times a week for 3 years and compared them with those in nine control subjects who consumed little or no local fish. No subjects or controls had other known significant exposures to DDT and its metabolites. The consumers of locally caught sportfish had significantly higher serum levels of total DDT (mean 35 ng/ml) than did nonconsumers (mean 7 ng/ml). Within the consumer groups, serum levels of 4,4′-DDE and fish consumption history were significantly correlated.
An evaluation of the fathead minnow seven-day subchronic test for estimating chronic toxicity
Authors: Norberg-King Teresa J. 
Published: March 2010

Abstract
Renewal and flow-through subchronic tests were conducted on fathead minnows (Pime-phales promelas) with nine chemicals and the results compared to early life stage (ELS) or life cycle toxicity values for one water type. In addition, ELS tests were conducted simultaneously with four chemicals to compare 7-d and 32-d test values.
Reproducibility of the 7-d test was high. The no observable effect concentrations (NOECs) and lowest observed effect concentrations (LOECs) of the 7-d tests agreed with those of the life cycle test for 60% of the chemicals tested, similar to the agreement of the ELS tests to the life cycle tests for the same chemicals. ELS and 7-d NOECs and LOECs for seven of the nine chemicals agreed within a factor of two.
For four chemicals, embryos exposed before the 7-d renewal test did not show greater sensitivity than unexposed embryos; with carbaryl, exposed embryos were less sensitive than the unexposed fish. Renewal and flow-through tests agreed well. Growth was the most sensitive parameter for 59% of the tests and survival was the most sensitive for only 11%.
Effect of methyl parathion on food discrimination in northern bobwhite (Colinus virginianus)
Authors: Bussiere Jeanine L. , Kendall Ronald J. , Lacher Thomas E. , Bennett Richard S. 
Published: March 2010

Abstract
The effect of methyl parathion on dietary discrimination ability was assessed in two-week-old northern bobwhite (Colinus virginianus). An initial oral dose of methyl parathion (0, 3 or 6 mg/kg: O,O-dimethyl O-(4-nitrophenyl) ester) was given to two subgroups of bobwhite before a 6-d food discrimination test; one group was tested with a choice of food treated with 45 ppm methyl parathion versus normal food and the second with a choice of 90 ppm treated food versus normal food. The average discrimination ratios (i.e., amount of treated to untreated food consumed) were used to indicate the chicks' ability to discriminate and avoid contaminated food. Chicks administered 6 mg/kg methyl parathion did not discriminate between treated and untreated food at either food treatment level and initially chose treated over untreated food (ratio = 1.28; p &lt; 0.05). Brain cholinesterase activity in the 6 mg/kg groups averaged 50% of control levels, indicating high exposure to methyl parathion, which correlated with a behavioral disturbance (i.e., preference for treated food on day 1). Cholinesterase activity did not correlate with the discrimination ratios throughout the remainder of the 6-d exposure period due to the strong side preference that developed in the treated groups. This study demonstrates that feeding behavior and taste discrimination ability of bobwhite chicks was impaired due to exposure to methyl parathion.
A littoral enclosure for replicated field experiments
Authors: Brazner John C. , Heinis Larry J. , Jensen Douglas A. 
Published: March 2010

Abstract
A design for 5 × 10 m littoral enclosures that extend 10 m from the shoreline into the zone of submergent vegetation and incorporate undisturbed natural sediments for the bottom is presented and construction techniques are described. This type of enclosure was used to study the responses of caged and free-living pond biota and the physical and chemical environment to a single application of Dursban® (chlorpyrifos) during the summer of 1986 as part of the development of a field testing protocol for pesticides needed by the U.S. Environmental Protection Agency Office of Pesticide Programs. Chlorpyrifos was added to 12 littoral enclosures built within a mesotrophic, 2-ha pond near Duluth, Minnesota, at nominal concentrations of 0.0, 0.5, 5.0 or 20.0 m̈g/L. The enclosures proved to be both economical and durable and were useful for detecting direct and indirect (ecological) effects of the pesticide. Coefficients of variation (C.V.) associated with the chemical and biological response variables typically ranged from 10 to 40%. The ability to simultaneously monitor many response variables in replicate enclosures at a relatively low cost suggests that the littoral enclosure design should be useful for studying the effects of pesticide or other pollutant additions to natural aquatic systems.
Preference/avoidance testing of waste discharges on anadromous fish
Authors: Smith Edmund H. , Bailey Howard C. 
Published: March 2010

Abstract
In the laboratory, preference/avoidance behavioral testing was used to investigate the potential of both domestic and industrial waste discharges to interfere with the migration of anadromous fish. Various dilutions of the effluents were tested using the behavioral response of fish as measured by linear velocity, locational position and other factors. A video-based computerized system was used to capture and analyze the behavioral data in real time. Test species were chinook salmon, Oncorhynchus tshawytscha, striped bass, Morone saxatilis and steelhead, Salmo gairdneri. Dilution rates were established based upon dye studies and waste field dispersion modeling. Dilutions down to 1,000:1 were tested and evaluations of the potential for each discharge to affect fish migrations were made. Both attraction and avoidance responses were observed at different concentrations of the discharges studied. Test fish exhibited strong responses at levels as low as 1,000:1 of effluent. Laboratory behavioral data were compared with field surveys where possible. A discussion of behavioral testing as a tool to assess the potential effects of discharges on fish migration is presented.
Sublethal toxicant effects on fish foraging behavior: Empirical vs. mechanistic approaches
Authors: Sandheinrich Mark B. , Atchison Gary J. 
Published: March 2010

Abstract
Previous studies of toxicant effects on fish foraging behavior and predator-prey interactions have taken a strictly empirical approach. The most common observation of altered feeding behavior was cessation of feeding or reduction in the amount of artificial food consumed. Changes in the number of live prey attacked and captured, latency to feed and capture efficiency have also been documented. Predator-prey tests have placed major emphasis on toxicant effects on the ability of prey to escape predation. Several different test systems, as well as model ecosystems, have been used. It is difficult to evaluate the sensitivity of these behavioral tests in relation to standard chronic tests. There was no consistency in test design, and few studies provided information on chemical effects on reproduction or growth in conjunction with behavioral effects. These empirical studies have little basis in ecological theory and do not allow development of testable hypotheses a priori to field verification of laboratory results. Few laboratory feeding studies have been verified in the wild. A mechanistic approach to feeding studies using optimal foraging and bioenergetics models may provide sensitive tests of contaminant effects that may be readily verified in the field. Model simulations demonstrate how toxicant effects on components of fishes' predation sequence can modify the size-frequency distribution of prey in the fishes' diet and how reductions in the amount of food consumed may alter growth.
Prediction of contaminant accumulation by free-living organisms: Applications of a sigmoidal model
Authors: Brisbin I. Lehr , Newman Michael C. , McDowell Susan G. , Peters Eric L. 
Published: March 2010

Abstract
The accumulation of contaminants by free-living organisms has traditionally been determined with permutations of the deterministic model: Ct = Ce(1 – e−kt). However, studies utilizing a variety of species and exposure scenarios now suggest that significant deviations may occur from this classic form. In many cases noted to date, these deviations have involved a sigmoidal pattern of accumulation. While there may be no one single causal mechanism responsible for the expression of such a pattern in all cases studied, the application of a flexibly shaped Richards sigmoidal model can improve goodness of fit to the data relative to the classic model form. Several examples are presented for use of the Richards model: accumulation of 137Cs by free-living American coots (Fulica americana) and yellow-bellied turtles (Pseudemys scripta), and Hg accumulation by mosquitofish (Gambusia affinis).
Fate of PAH compounds in two soil types: Influence of volatilization, abiotic loss and biological activity
Authors: Park Kap S. , Sims Ronald C. , Dupont R. Ryan , Doucette William J. , Matthews John E. 
Published: March 2010

Abstract
The fate of 14 polycyclic aromatic hydrocarbon (PAH) compounds was evaluated with regard to interphase transfer potential and mechanisms of treatment in soil under unsaturated conditions. Volatilization and abiotic and biotic fate of the PAHs were determined using two soils not previously exposed to these compounds. Volatilization accounted for approximately 30 and 20% loss of naphthalene and 1-methylnaphthalene, respectively; for the remaining compounds, volatilization was negligible. Abiotic reactions accounted for approximately 2 to 20% of the reduction in concentration in solvent extracts for two- and three-ring PAH compounds; no statistically significant reduction was observed for PAH compounds containing greater than three aromatic rings. Biotic mechanisms were quantified as first-order rate constants corrected for volatilization and abiotic mechanisms. Half-life values increased from approximately 2 to 60 to more than 300 d for two-, three- and four- and five-ring PAH compounds, respectively. In general, biological degradation rates were not significantly different between the two soils. Information concerning interphase transfer potential and mechanisms of treatment provides the basis for a rational approach to remediation of soil contaminated with PAH compounds.
Benthic invertebrate bioassays with toxic sediment and pore water
Authors: Giesy John P. , Rosiu Cornell J. , Graney Robert L. , Henry Mary G. 
Published: March 2010

AbstractThe relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. The assays studied were: (a) Microtox®, a 15-min assay of Photobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magna lethality test in pore water; (c) 10-d subchronic assay of lethality to and reduction of weight gain by Chironomus tentans performed in either whole sediment or pore water; (d) 168-h acute lethality assay of Hexagenia limbata in either whole sediment or pore water. The three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. Based on lethality, H. limbata was the most sensitive organism to the toxicity of Detroit River sediment. Lethality of D. magna in pore water was similar to that of H. limbata in whole sediment and can be used to predict effects of whole sediment toxicity to H. limbata. The concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna (48-h LC50) and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. While the three dilution techniques gave similar results with some assays, they gave very different results in other assays. The dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.
Field research on aldicarb management practices for upstate New York
Authors: Porter Keith S. , Wagenet Robert J. , Jones Russell L. , Marquardt Terry E. 
Published: March 2010

Abstract
The need to develop aldicarb management practices in upstate New York potato fields, which would continue the benefits associated with the pesticide while protecting drinking water wells, led to a three-part research program conducted in 1983: Samples from 57 wells and three test holes were collected near potato fields in six counties; aldicarb residues were monitored in water from a tile-drained field near Willsboro; and a study of aldicarb residues in the unsaturated zone was conducted in a potato field near Phelps. Results show that aldicarb residues from applications made in June degrade with a half-life of about one month in surface soils. The persistence and transport of aldicarb residues from these later applications is shown to be less compared to the usual previous practice of applying aldicarb at planting. The potable well sampling indicates that where applications are made at the usual planting time in midspring, aldicarb residues may appear in drinking water wells located very near the treated fields. The results of this and other related studies confirm the soundness of later applications of aldicarb when the soils are warmer and when there is less soil water percolation. This practice is embodied in the current North Eastern regulations, which require application of aldicarb at plant emergence and prohibit applications within 150 m of drinking water wells.