bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of toxins from natural blue-green algae and unicellular cultured Microcystis aeruginosa
Authors: Jinno Hideto , Ando Masanori , Matsui Sachiko , Takeda Mitsuharu
Published: March 2010

The differences between toxins derived from natural populations and cultures of Microcystis aeruginosa and Microcystis viridis, and the toxins of harvested extracts from four strains of Microcystis were investigated using DEAE-cellulose chromatography. Toxins extracted from algal populations consisting of 75% (total Microcystis cells/ml) M. aeruginosa from Lake Kasumigaura, Japan, contained an F-II fraction determined by ion-exchange chromatography; toxins extracted from algal populations consisting of 70% M. viridis from Lake Suwa, Japan, also contained this fraction. Using an improved gradient procedure with ion-exchange chromatography to analyze crude extracts of unicellular cultures of M. aeruginosa strain PS-434, five extracted fractions — F-II, F-IV, F-V, F-VI and F-VII — were determined to contain toxic substances. These fractions were identified as toxic (intraperitoneal injection) in mouse toxicity studies. No toxic fractions were identified in cultures of M. aeruginosa strain NIES-44. Mice LD50s for the crude extracts of cultures of strain PS-434 and the extracts from Lakes Kasumigaura and Suwa were calculated as less than 89.5, 260 and 570 mg/kg, respectively. In natural populations of M. aeruginosa or M. viridis, four toxic fractions (F-IV, F-V, F-VI and F-VII) were not found.
Comparative acute toxicity of diethyleneglycol dinitrate to freshwater aquatic organisms
Authors: Fisher Daniel J. , Burton Dennis T. , Paulson Robert L.
Published: March 2010

The acute toxicity of diethyleneglycol dinitrate (DEGDN) to nine freshwater aquatic organisms was determined. Juvenile fathead minnow, bluegill, channel catfish and rainbow trout were exposed to the compound for 96 h. The invertebrates tested for 48 h included the neonate water flea, early-young amphipod, midge larva and the mayfly larva. The effect of DEGDN on the growth of the green alga Selenastrum capricornutum was also studied.

The toxicity of DEGDN was relatively low to the nine freshwater species tested. Toxicity values ranged from a 5-d EC50 (standing crop) of less than 58.4 mg/L for the alga to a 96-h LC50 of 491.4 mg/L for the fathead minnow. The most sensitive invertebrate, the daphnid, was more sensitive than the most sensitive fish, the bluegill.
Toxicity of 2-sec-butyl-4,6-dinitrophenol (dinoseb) and monosodium methanearsonate (msma), individually and in a mixture, to channel catfish (Ictalurus punctatus) and fathead minnows (pimephales promelas)
Authors: Skelley John Royal
Published: March 2010

The toxicity of technical-grade dinoseb, technical monosodium methanearsonate (MSMA), several formulations of each and a mixture of the two were tested using channel catfish (Ictalurus punctatus Rafinesque) and fathead minnows (Pimephales promelas Rafinesque) under standard conditions at 12°C in soft, reconstituted water. The 96-h LC50s for technical dinoseb were 0.058 mg/L for channel catfish and 0.088 mg/L for fathead minnows. Differences among Vertac General®, Vertac Selective®, Premerge 3®, Gebutox® and technical dinoseb did not affect dinoseb toxicity to either fish species. The 96-h LC50s for technical MSMA were 2,390 mg/L for channel catfish and 1,210 mg/L for fathead minnows. Formulation had a measurable effect on MSMA toxicity, with the Daconate® and Daconate 6® formulations nearly an order of magnitude more toxic than technical MSMA and Bueno 6® to both fish species. The mixture or joint toxicity of technical dinoseb and technical MSMA was greater than additive (synergistic), with additive toxicity indices for channel catfish and fathead minnows of 0.51 and 5.78, respectively.
Chronic effects of contaminated sediments on the urchin Lytechinus pictus
Authors: Thompson Bruce E. , Bay Steven M. , Anderson Jack W. , Laughlin Jimmy D. , Greenstein Darrin J. , Tsukada David T.
Published: March 2010

The urchin, Lytechinus pictus, one of the most abundant species on the mainland shelf off southern California, was exposed to three of the most contaminated sediment types in the region and a control (reference) sediment. Mortality, growth, gonad production and bioaccumulation were measured in the laboratory for 60 d in flow-through experiments. Significant mortality (49%) occurred in Santa Monica Bay sludge outfall sediment. Growth rates were significantly reduced in sediments from Los Angeles Harbor, Palos Verdes sewage outfall and Santa Monica Bay sludge outfall. Both male and female gonad production was significantly decreased in the Santa Monica Bay sludge and Palos Verdes outfall sediments. Gonads accumulated up to 12.6 ppm DDTs and 7.4 ppm polychlorinated biphenyls but decreased in concentrations of Zn, Cu and Cd. The biological effects measured could have been caused by several types of contaminants and were significantly correlated with many of the contaminants measured in the sediments.
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

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

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

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

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

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

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

Freshwater 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

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

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

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 < 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

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

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

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

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

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

The 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

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.
Inhibition of brain and plasma cholinesterase activity in zebra finches orally dosed with fenitrothion
Authors: Holmes Stephen B. , Boag Peter T.
Published: March 2010

Zebra finches (Poephila guttata) were given single oral doses of fenitrothion insecticide dissolved in soya bean oil. Brain and plasma cholinesterase (ChE) activities were measured periodically up to 10 d postexposure. Dosage rates of 1.04, 3.80 and 11.36 mg active ingredient/kg body weight resulted in maximum brain ChE inhibitions of 50, 70 and 75%, and maximum plasma ChE inhibitions of 78, 82 and 89%, respectively. Recovery of ChE activity in vivo followed an exponential pattern, with plasma ChE activity recovering more rapidly than brain ChE activity. At dosage rates of 1.04 and 3.80 mg/kg, plasma ChE activity recovered to normal in 1 to 2 d. Brain ChE activity was inhibited up to 10 d after dosing at 1.04 mg/kg. There was some mortality of exposed birds at the two higher dosage rates. Birds that died exhibited brain ChE inhibitions ranging from 3 to 84%.
Effect of sediment test variables on selenium toxicity to Daphnia magna
Authors: Stemmer B.L. , Burton G.A. , Leibfritz-Frederick S.
Published: March 2010

The effects of three test method variables (spiking method, sediment storage and sediment: water ratio) on solid-phase sediment toxicity of selenite-spiked sediments were investigated using Daphnia magna 48-h acute exposures. Spiking methods compared stirring and shaking of selenite with sediments followed by toxicity testing from 4 to 72 h. The two methods produced similar LC50 values; however, significant toxicity changes occurred over time. The effect of mixing spiked sediments from 0.5 to 48 h showed decreased toxicity after 24 and 48 h of shaking. Storage of selenite-spiked sediments at 4 and 25°C revealed significant differences in LC50 values between storage temperatures and with time of storage. Toxicity tended to decrease faster in sediments stored at 25°C. Sediment: water comparisons varied the volume of sediment and water used in test beakers and the sediment surface area. In general, only extreme sediment: water ratios affected survival. Varying the sediment surface area while maintaining a constant 1:4 ratio did not alter survival. An increased surface area and a decreased sediment: water ratio (1:8) decreased survival.
An in situ study on the distribution, biotransformation and flux of polycyclic aromatic hydrocarbons (pahs) in an aquatic food chain (seston-Mytilus edulis L.-Somateria mollissima L.) from the baltic: An ecotoxicological perspective
Authors: Broman Dag , Näuf Carina , Lundbergh Ivar , Zebühr Yngve
Published: March 2010

This in situ study is focusing on the distribution, biotransformation and flux of 19 polycyclic aromatic hydrocarbons (PAH19) in the food chain seston-blue mussel (Mytilus edulis L.)-common eider duck (Somateria mollissiima L.) as well as the distribution in the gallbladder, liver, adipose tissue and egg of the duck. All samples were collected within the open northern Baltic proper coastal areas. Analyses were carried out by gas chromatography/mass spectrometry with electron impact (GC-MSEI) and negative ion chemical ionization (GC-MSNICI). With a multivariate statistical method (SIMCA) a significant change in the PAH composition through the food chain was found. This change probably depends on an increasing metabolic activity with increasing trophic level, due to a selective biotransformation capacity for different PAHs. Decreasing PAH concentrations with increasing trophic level were found. The PAH concentrations in the different eider duck organs were: gallbladder > adipose tissue ≥ liver. The theoretical inhalation of air-dispersed PAHs was of no significance compared to the exposure from food. The relatively high theoretical PAH flux through the food chain did not result in increasing concentrations with increasing trophic level, which indicates that PAHs are biotransformed quite fast. However, many intermediate metabolites of PAHs have a mutagenic and carcinogenic potential, which makes it important to observe these compounds when assessing ecotoxicological risks.
Influence of digestive processes on the absorption and fate of quinoline ingested by rainbow trout (Oncorhynchus mykiss)
Authors: Dauble Dennis D. , Curtis Lawrence R.
Published: March 2010

Rainbow trout were fed pelleted food containing [14C]-quinoline to assess the relationship of digestive processes to xenobiotic pharmacokinetics. The pH of material in the stomach of rainbow trout ranged from 2.7 to 5.2 and was highly correlated (r = 0.89) with the size of the food bolus remaining. At 2 h after feeding, 67% of the quinoline was estimated to be un-ionized and available for absorption across gastric epithelium. Quinoline was >99% un-ionized in the alkaline environment of the intestine; however, relative concentrations in the intestine were about 8% of those measured in the stomach. Gastric absorption was consistent with known serum profiles and excretion patterns of dietary quinoline. Rates of gallbladder emptying appeared to exceed rates of hepatic bile secretion until about 8 h after a single feeding. Time since feeding influenced both the amount and concentration of quinoline-derived radioactivity in the bile. Consecutive feedings enhanced the movement of the food bolus and associated radioactivity from the upper and midgut regions, but had no effect on disposition of quinoline.
Effects of carbofuran, chlorpyrifos and deltamethrin on hatchability, deformity, chick size and incubation time of Japanese quail (Coturnix japonica) eggs
Authors: Martin Pamela A.
Published: March 2010

Japanese quail (Coturnix japonica) eggs were immersed in aqueous emulsions of carbofuran, chlorpyrifos and deltamethrin at three potential field concentrations and at three stages of incubation. No effects of pesticide exposure on hatchability were detected. There were no significant effects of carbofuran on rate of hatchling deformity, incubation time, chick mass or tarsus length. Eggs treated immediately prior to incubation with chlorpyrifos at two times the recommended field application level had a significantly greater rate of hatchling deformity (e.g., foot malformations and scoliosis) and a longer incubation period than controls. Eggs exposed to two times field application rates of deltamethrin at the preincubation stage had significantly longer incubation periods and eggs exposed to this rate of deltamethrin on incubation day 14 produced significantly lighter chicks than controls. Overall, effects were small and the three insecticides did not represent a significant hazard to quail embryos at conditions up to two times field levels of application.
Runoff-induced metals in Lakes Bay, New Jersey
Authors: Parrish Camille S. , Uchrin Christopher G.
Published: March 2010

Lakes Bay, an estuarine embayment located near Atlantic City, New Jersey, currently supports commercial shellfishing; however, the surrounding basin is a prime location for development. Synpotic surveys were conducted during the summer of 1986 to determine background conditions and the response to stormwater runoff inputs of three metals; copper, lead and cadmium. Background (dry weather) conditions of all three metals were found to be not significantly different than those reported for world natural waters. Significant amounts of lead and copper were found to be input to the system through a major storm water sewer that discharges to a lagoon. Sediment analysis showed that considerable sedimentation occurs in this lagoon, thus localizing the effect of this input to the system. A local stormwater retention basin was not found to be a significant source of metals. Cadmium levels were not found to be significantly different between dry and wet weather conditions. The high salinity of the system required extensive sample extraction procedures prior to analysis by atomic absorption spectrophotometry to minimize matrix interferences.
Photochemical degradation rates of tetraphenylborate and diphenylboric acid sensitized by dissolved organic matter in stream water
Authors: Mills Gary L. , Schwind Donna
Published: March 2010

The photochemical degradation of tetraphenylborate (TPB) and diphenylboric acid (DPBA) was studied in stream water and humic acid solutions. The rates of indirect photolysis of TPB and DPBA were similar and directly proportional to the concentration of stream water dissolved organic matter (DOM) and humic acid for values < 10 mg/L. Direct photolysis of both organoborates was nondetectable during a 2-h irradiation period. Indirect photolysis rates varied only slightly from pH 6.0 to 9.0, but increased markedly below pH 6.0. Removal of dissolved oxygen increased reaction rates by a factor of two, indicating that the reaction mechanism does not involve singlet oxygen oxygenation.
Humic acids reduce the photo-induced toxicity of anthracene to fish and daphnia
Authors: Oris James T. , Hall A. Tilghman , Tylka Jacqueline D.
Published: March 2010

The effects of dissolved humic materials (DHM) on the photo-induced toxicity of anthracene to fathead minnows (Pimephales promelas) and daphnia (Daphnia magna) were studied in a laboratory system under simulated sunlight. In the fathead minnow toxicity tests, four concentrations of anthracene (0, 6.6, 13.1 and 19.1 μ g/L) and five concentrations of DHM (0, 0.5, 1.0, 3.0 and 6.0 mg C/L) were achieved. In the daphnia toxicity tests, four concentrations of anthracene (0, 5.58, 10.49 and 21.03 μ g/L) and four concentrations of DHM (0, 0.8, 2.7 and 6.9 mg C/L) were achieved. DHM significantly reduced acute photo-induced toxicity in both organisms. Median lethal times (LT50) were directly related to DHM concentration and inversely related to water anthracene concentration across the tested ranges of each variable. The presence of DHM also reduced anthracene bioaccumulation, and LT50 values for both fish and daphnia were inversely related to body anthracene concentration. Findings presented in this study demonstrate that the photo-induced toxicity of anthracene is primarily a fugacity-dependent phenomenon, that selective attenuation of the active wavelengths of solar ultraviolet radiation by DHM also results in a decreased level of acute toxicity and that a common mode of acute photo-induced toxicity between fish and daphnia exists.
Multi-steady-state toxicant fate and effect in laboratory aquatic ecosystems
Authors: Burnett Kelly M. , Liss William J.
Published: March 2010

The influence of competition, exploitation and level of energy input on toxicant fate and effect in simple aquatic laboratory ecosystems was studied. Twenty-four systems composed of populations of guppies (Poecilia reticulata), snails (family Planorbidae) and various taxa of algae were maintained in 40-liter flow-through glass aquaria. Guppies and snails were competitors for a common food resource. Ecosystems were established in which guppies and snails were sympatric and allopatric. The systems were exposed to three levels of guppy exploitation and received two levels of energy input. System dynamic and near steady-state behavior were documented through monthly measurements of population biomasses. Biomasses of interacting populations were displayed on phase planes. Shifts in system structure followed chronic exposure to a sublethal concentration of dieldrin. System responses to the toxicant ranged from increased population biomass to population extinction and were influenced by level of exploitation, energy input rate and species competition. Toxicant concentrations were determined in adult female fish. Both toxicant effect and fate were influenced by system organization and environment. Quite different conclusions concerning toxicant performance in these systems could have been drawn if observation had been restricted to only one set of organizational and environmental conditions.
Henry's law constants for selected pesticides, PAHs and PCBs
Authors: Fendinger Nicholas J. , Glotfelty Dwight E.
Published: March 2010

Henry's law constants (HLCs) were determined for 12 pesticides, 9 polynuclear aromatic hydrocarbons (PAHs) and 2 polychlorinated biphenyl (PCB) congeners using a wetted-wall column (WWC) technique. The WWC equilibrates an organic solute between a thin film of water and a concurrent flow of air in a vertical column. Air and water collected from the WWC were either solvent extracted or trapped on solid phase sorbents and were analyzed by gas chromatographic methods. HLCs were calculated from analyte concentrations in air and water collected from the WWC. Results of the HLCs determined by the WWC are compared with calculated values and determinations made by other investigators using purge bottle and static equilibration techniques.
Effects of acidification on minor and trace metal chemistry in little rock lake, wisconsin
Authors: Brezonik Patrick L. , Mach Carl E. , Downing Gregg , Richardson Nancy , Brigham Mark
Published: March 2010

Little Rock Lake is a low-alkalinity (25 μeq/L, pH 6.1) seepage lake in north-central Wisconsin. The two main basins of the lake were separated by a polyvinyl barrier in 1984, and acidification of the north basin with H2SO4 began in spring 1985; the south basin is being maintained as a reference. The effects of acidification on dissolved concentrations of Al, Fe, Mn, Cd, Cu, Ni, Pb and Zn have been studied at three scales at Little Rock Lake: (A) laboratory-scale experiments with well-mixed sediments; (b) large (4- to 5-m dia) in situ enclosures maintained at pH 4.5 to 6.0; and (c) the lake itself. In general, qualitative agreement is good between the three approaches, but some differences have been observed, especially for Al and Fe. The most significant trace metal response observed in acidifying the north basin from pH 6.1 to 5.1 has been a large increase in dissolved Mn, apparently as a result of hindered oxidation of Mn2+ at lower pH. Dissolved Al and Fe also increased at pH 5.1 but not at 5.6. Water column levels of Cd, Cu, Pb and Zn have not increased at pH 5.1 in the lake, but results of lab and enclosure studies suggest that increased concentrations of Cd and Zn will occur when the lake is acidified to pH 4.6. Sediment cores and surface sediments from both basins of the lake have been collected and analyzed for Al, Fe, Mn, Cd, Cu, Hg, Ni, Pb and Zn. Similar concentrations of most metals were found in surface sediments from both basins of the lake. Near-surface sediments were enriched in Hg and Pb relative to deeper sediment layers; the enrichment is presumed to be caused by increased atmospheric inputs during the past century, not diagenetic activity. No consistent differences in the Hg content of zooplankton, periphyton and benthic invertebrates were found at pH 5.6 and 5.1 in the acidified basin compared with the pH 6.1 reference basin.
Factors affecting mercury accumulation in fish in the upper michigan peninsula
Authors: Grieb Thomas M. , Bowie George L. , Driscoll Charles T. , Gloss Steven P. , Schofield Carl L. , Porcella Donald B.
Published: March 2010

Fish were sampled from 35 drainage and seepage lakes in the upper Michigan peninsula and Wisconsin in conjunction with Phase II of the U.S. Environmental Protection Agency's Eastern Lake Survey to explore the relationship between physicochemical characteristics of lakes and mercury concentrations in fish tissue. The lakes were selected using a stratified random design weighted for low pH to assess acidification effects on mercury bioaccumulation. Muscle tissue from yellow perch (Perca flavescens), northern pike (Esox lucius), white sucker (Catostomus commersoni) and largemouth bass (Micropterus salmoides) was analyzed for total and methylmercury. Differences in mercury concentrations were found between species, and methylmercury accounted for 99% of total mercury. Relationships were examined between tissue concentrations of mercury in yellow perch and lake physicochemical variables including pH, acid neutralizing capacity (ANC), calcium, conductivity, aluminum, total phosphorus, dissolved organic carbon, color, sulfate, lake area, lake depth, watershed area, Secchi depth and elevation. Mercury concentrations were negatively correlated with pH and ANC for both seepage and drainage lakes, but correlations with other water-quality characteristics varied with lake type. Dissolved organic carbon had a negative correlation with fish mercury accumulation in seepage lakes, but not in drainage lakes. Mercury concentrations had a positive correlation with age, weight and length in yellow perch.
Human health risks from methylmercury in fish
Authors: Clarkson Thomas William
Published: March 2010

Human health risks from methylmercury in fish are evaluated in terms of dose-response relationships for both adult and prenatal human exposures. Specifically, information has become available from three independent epidemiological studies indicating that methylmercury levels in the mother during pregnancy predict the probability of adverse effects in her offspring. The mercury levels in the mother are measured as concentration in head hair which in turn is an excellent predictor of blood concentration. The adverse effects in the offspring take the form of psychomotor retardation. These dose-response relations along with a one-compartment kinetic model for methylmercury accumulation in humans will be used to estimate minimum toxic daily intakes; these are, for nonpregnant adults, 4,300 ng Hg/kg body weight/d and about 600 to 1,100 ng Hg/kg/d for pregnant adults. These values assume continuous exposure until the individual has attained steady state balance with respect to the body burden of methylmercury. This will take up to one year in most cases.
Hydrolysis of chlorostilbene oxide II. Modeling of hydrolysis in aquifer samples and in sediment-water systems
Authors: Metwally Mohammed El-Sayed , Lee Wolfe N.
Published: March 2010

The disappearance kinetics of 4-chlorostilbene oxide (CSO) were determined in aquifer samples and in sediment-water systems to derive kinetic expressions that describe heterogeneous effects. Disappearance rate constants were determined in heterolytic systems and compared with those obtained in distilled water to delineate the effect of solids on the kinetics of hydrolysis. In both neutral and acid hydrolysis studies, the sorption-desorption rates of CSO were faster than the hydrolysis rates in either the aqueous or sediment-sorbed phases. Both dissolved and sorbed CSO hydrolyzed at either neutral or acidic pHs. Above pH 5, where neutral hydrolysis dominates, the hydrolysis rate constant of CSO in sterile sediment-water systems was the same as in distilled water. This suggests that sorption neither retards nor promotes the neutral hydrolysis pathway. At pHs below 5, where acid hydrolysis dominates, the pseudo-first-order hydrolysis rate constant was lower for the sorbed fraction than the rate constant in distilled water at the same pH. This indicates that hydrolysis rate constant in the sorbed phase is slower than that in the bulk aqueous phase.

Kinetics of hydrolysis were studied in raw sediment samples and samples sterilized by heat or with formalin to distinguish between abiotic and biotic hydrolysis processes. Above pH 5, the hydrolysis rate constants were larger in nonsterile systems when compared with the rate constants in the sterile systems, suggesting that both biotic and abiotic pathways contribute to the disappearance of CSO. Below pH 5, the hydrolysis rate constants were, within experimental error, the same in the sterile and nonsterile systems. In aquifer samples, the average disappearance rate constant of CSO was 0.85 (±0.11) × 10−4 min−1, which is about the same as the rate constant in distilled water. These results suggest that there is no heterolytic enhancement of the neutral hydrolysis rate constant by the aquifer materials.