bluuebunny/crossref_metadata_2025_split huggingface dataset:
Problems induced by the use of acetone as a solvent to dose chlorpyrifos in a microecosystem
Authors: Kersting Kees 
Published: March 2010

Abstract
Recycling aquatic microecosystems consisting of three subsystems with a total volume of 7.5 L were used to study the effects of the insecticide chlorpyrifos. The poorly soluble chlorpyrifos was dosed dissolved in 0.5 ml of acetone. Acetone was found to be responsible for some of the observed effects. It caused a decrease of the pH by approximately two units. The decrease started 2 weeks after the introduction, and recovery to the pretreatment level took several months.
Concentrations, transport and biological effects of dormant spray pesticides in the San Francisco Estuary, California
Authors: Kuivila Kathryn M. , Foe Christopher G. 
Published: March 2010

Abstract
The transport and biological effects of dormant spray pesticides were examined in the San Francisco Estuary, California, by measuring dissolved-pesticide concentrations and estimating toxicity using bioassays at a series of sites in January and February 1993. Distinct pulses of pesticides, including diazinon, methidathion, and chlorpyrifos, were detected in the San Joaquin River in January and February and in the Sacramento River in February following rainfall. The higher pesticide loads in the Sacramento River compared with those in the San Joaquin River can be attributed to the greater amount of rainfall in the Sacramento Valley. The use patterns and water solubility of the pesticides can account for the observed temporal and spatial distributions in the two rivers. The pesticide pulses detected at Sacramento were followed through the northern embayment of San Francisco Estuary. In contrast, the pesticide distribution in the Sacramento-San Joaquin Delta changed from distinct pulses to steady increases in concentration over time. Seven-day bioassays indicated that Sacramento River water at Rio Vista was acutely toxic to Ceriodaphnia dubia (water flea) for 3 consecutive d and San Joaquin River water at Vernalis for 12 consecutive d. These water samples all had the highest diazinon concentrations. Examination of 96-h LC50 values (lethal concentration that kills 50% of test organisms in 96 H) indicates that measured diazinon concentrations could account for most but not all the observed toxicity. Other pesticides present could contribute to the toxicity.
The effect of malathion 60 on Gammarus pulex (L.) below watercress beds
Authors: Crane Mark , Delaney Paul , Watson Samantha , Parker Penny , Walker Colin 
Published: March 2010

Abstract
The organophosphorus insecticide Malathion 60 is used to control terrestrial arthropod pests on watercress, Rorippa nasturtium-aquaticum L. (Hayek). The use of this pesticide could damage aquatic invertebrate communities in nearby chalk streams, so an in situ experiment was undertaken with the amphipod Gammarus pulex L. to determine the extent of this risk. Caged G. pulex were placed below two selected watercress beds and their associated settling pools, and their mortality, feeding rate, and acetylcholinesterase activity measured before and after the application of Malathion 60 to the watercress crop. The differences found between prespray and postspray samples of G. pulex taken from the stations immediately below both watercress beds follow: (a) the acetylcholinesterase activity was significantly lower at both stations after spray application; (b) the mortality rate was significantly higher at one station after spray application, but not at the other; (c) there were no clear effects on feeding rates at either station. Also, there were no significant detrimental effects at either of the stations located below the settling pools. Results from this study suggest that the use of Malathion 60 on watercress beds at recommended rates presents little risk to G. pulex living in streams below watercress farms if bed effluent passes through a settling pool before release.
Minnows can acclimate to total residual chlorine
Authors: Lotts Joseph William , Stewart Arthur Jay 
Published: March 2010

Abstract
Observations in a chlorine-contaminated stream in eastern Tennessee revealed several species of fish in areas where total residual chlorine (TRC) concentrations were often great enough to be lethal, based on the results of other studies. We used in situ and laboratory experiments to test the hypothesis that minnows could acclimate to TRC. Acclimation was assessed by time-to-death for fish exposed to a single lethal regime of TRC. In in situ experiments, striped shiner and central stoneroller minnows collected from East Fork Poplar Creek at a TRC-contaminated site and a site farther downstream, where TRC was below detection, were caged at sites in the stream where TRC concentrations were either nil or great enough to be lethal. At the cage with high TRC, minnows collected from the “TRC-contaminated” site survived two to four times longer (15.8 h vs. 6.1 h) than the same species from the “TRC-free” site. In laboratory experiments, golden shiner minnows were exposed to TRC in a stepwise increasing concentration regime (0.04 mg/L during week 1, 0.08 mg/L during week 2, and 0.12 mg/L during week 3) before being challenge-tested with a lethal concentration of TRC. Minnows that had been previously exposed to TRC survived longer than controls in each test, and the magnitude of the mean time to death increased as the TRC concentration and duration of exposure increased (1.2-, 2.5-, and 3.9-fold increases for weeks 1, 2, and 3, respectively). Another experiment with golden shiner minnows showed that a 21-d exposure to TRC at a low concentration (0.04 mg/L) only slightly increased their tolerance to TRC. Thus, several minnow species apparently can acclimate, fairly rapidly, to TRC. This study may help explain why fish kills are less common than expected in TRC-contaminated streams.
Induction and characterization of hepatic metallothionein expression from cadmium-induced channel catfish (Ictalurus punctatus)
Authors: Zhang Y. S. , Schlenk Daniel 
Published: March 2010

Abstract
Two low-molecular-weight proteins of approximately 10,000 daltons (Da) were isolated from the hepatic tissue of catfish intraperitoneally injected with CdCl2 (5 mg/kg). Each protein was significantly induced following Cd treatment. Bound Cd, co-eluted from DEAE anion-exchange HPLC with rabbit hepatic metallothioneins I and II, did not possess UV absorption indicative of aromatic amino acids and corresponded to the expression of two mRNA transcripts of approximately 400 base pairs, which hybridized to a full-length cDNA probe to winter flounder metallothionein (MT). Because these data indicated that these two low molecular weight proteins were hepatic MT isoforms, induction of MT mRNA expression was studied in livers of channel catfish exposed to aqueous CdCl2 utilizing the ribonuclease protection assay. Following a 7-d exposure to 10, 50, and 100 μg/L CdCl2, expression of two MT mRNAs increased in a dose-dependent manner (MT-a, r2 = 0.95; MT-b, r2 = 0.98). Each transcript was maximally induced 48 h after exposure to 100 μg/L CdCl2 and then gradually declined to approximately 20% above controls after 96 h and maintained this level of expression for 7 d. Although MT expression is rapidly induced in channel catfish by Cd, and MT mRNA measurement is a sensitive indicator of MT induction, the use of hepatic MT of channel catfish may not be a sensitive bioindicator of short-term, low-level aqueous exposures of Cd.
Uptake and elimination of resin acids and physiological responses in rainbow trout exposed to total mill effluent from an integrated newsprint mill
Authors: Johnsen Kjell , Stuthridge Trevor R. , Mattsson Kaj , Tana Jukka , Lehtinen Karl J. , Hemming Jarl 
Published: March 2010

Abstract
The effects of thermomechanical pulping effluents from an integrated newsprint mill were tested on rainbow trout (Oncorhynchus mykiss). Continuous-flow exposures under laboratory conditions were conducted at three dilutions (1:200, 1:400, and 1:1,000) for 8 weeks, followed by a 4-week recovery period. Sublethal effects were assessed using physiological and biochemical parameters including liver histology, hematology, serum biochemistry, and hepatic enzyme assays. Exposure was verified by analyzing water column, fish bile, and fish tissues for resin-acid concentrations. The effluent was found to be lethally toxic to rainbow trout within 3 to 4 weeks at a dilution of 1:200. Resin-acid concentrations in bile, muscle, gill, and liver showed a clear-cut positive dose response. However, relatively few responses and changes in the physiological parameters analyzed were found when comparing exposed and reference fishes. The small differences in physiological parameters between the reference group and an exposure group (1:400) after a 4-week recovery period show that the observed responses were reversible. It is noteworthy that the difference between the lowest acutely toxic concentration and the concentration at which only slight physiological responses occurred was very narrow for this effluent.
Fate of octamethylcyclotetrasiloxane (OMCTS) in the atmosphere and in sewage treatment plants as an estimation of aquatic exposure
Authors: Mueller James A. , Di Toro Dominic M. , Maiello Joy A. 
Published: March 2010

Abstract
Ambient concentrations of the volatile octamethylcyclotetrasiloxane (OMCTS) in natural waters were predicted using two environmental-fate analyses: an atmospheric model and a sewage treatment plant model. The atmospheric-fate analysis utilizes a completely mixed model of the troposphere where degradation occurs by hydroxyl radical oxidation. The treatment plant analysis incorporates removal mechanisms of biodegradation, volatilization, and adsorption. The treatment train consisted of primary clarifiers followed by secondary treatment using an activated sludge process. Two estimates of influent concentration were used in the model, one based on total consumption data and the other based on measured sludge data. Because of the widely varying estimates, a sampling program was undertaken and the data were used for final effluent estimates. Measured influent OMCTS concentrations of several wastewater treatment plants indicated that less than 5% of the consumable OMCTS is received by treatment plants. From the atmospheric analysis, the predicted OMCTS concentration in the ambient water in equilibrium with the atmosphere is from 10−5 to 10−8 μg/L. Using measured influent concentrations, the sewage treatment plant analysis predicted average effluent concentrations of 0.39 to 0.66 μg/L. Both analyses predicted concentrations that were less than the lowest chronic no-observed-effect concentration (4.4 μg/L), thus providing no significant aquatic exposure.
Displaying multimedia environmental partitioning by triangular diagrams
Authors: Lee Sum Chi , Mackay Donald 
Published: March 2010

Abstract
It is suggested that equilateral triangular diagrams are a useful method of depicting the equilibrium partitioning of organic chemicals among the three primary environmental media of the atmosphere, the hydrosphere, and the “organosphere” (natural organic matter and biotic lipids and waxes). The technique is useful for grouping chemicals into classes according to their partitioning tendencies, for depicting the incremental effects of substituents such as alkyl groups and chlorine, and for showing how partitioning changes in response to changes in temperature.
Holding-time estimates for soils containing explosives residues: Comparison of fortification vs. field contamination
Authors: Grant Clarence L. , Jenkins Thomas F. , Myers Karen F. , McCormick Erika F. 
Published: March 2010

Abstract
Maximum acceptable preextraction analytical holding times (MHTs) were estimated by spiking aqueous solutions of two nitramines, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and three nitroaromatics, 1,3,5-trinitrobenzene (TNB), 2,4,6-trinitrotoluene (TNT), and 2,4-dinitrotoluene (2,4-DNT), into three soils. Nitramines were stable over an 8-week test period at all storage temperatures, but nitroaromatics, which were reasonably stable when frozen, degraded rapidly at room temperature and more slowly under refrigeration. In contrast, both nitroaromatics and nitramines were quite stable under refrigeration for four field-contaminated soils. When three of these field-contaminated soils were subsequently fortified with TNT and TNB, rapid degradation under refrigeration was again observed for the added nitroaromatics. The rates of degradation were quite different in the three soils, further emphasizing the uncertainties in MHT estimates derived from fortified soils. We conclude that fortified soils can produce very different estimates of MHTs, recoveries, treatability, etc., compared to field-contaminated soils even when spiking is done in aqueous media.
The effect of 210Pb and stable lead on the induction of menta deformities in chironomus tentans larvae and on their growth and survival
Authors: Bird Glen A. , Schwartz William J. , Joseph Dana L. 
Published: March 2010

Abstract
To determine whether menta deformities in chironomid larvae collected from Port Hope Harbour, Ontario, were the result of exposure to ionizing radiation or to heavy metals in the sediment, Chironomus tentans larvae were exposed in the laboratory to concentrations of 210Pb and stable lead representative of contaminant levels in the harbour. Exposure to 100, 1,000, and 2,000 Bq 210Pb g−1 dry sediment had no effect on larval survival, growth, or frequency of deformities. Likewise, exposure to 0.5 and 5.0 mg lead g−1 dry sediment had no effect on the larvae, but exposure to 35.0 mg lead g−1 dry sediment (the maximum levels observed in Port Hope Harbour) resulted in 100% mortality of the larvae. These results indicate that the observed mouthpart deformities in chironomid larvae of Port Hope Harbour are not the result of radiation exposure. They also indicate that heavy metals (lead) may be having an impact on the Port Hope Harbour population. Deformities were observed in all treatments and were confined mainly to the median tooth, with cleft or forked median teeth being the most common deformity. Restriction of the deformities to the median tooth is consistent with an inherited genetic effect, and we consider them to be natural abnormalities. These natural abnormalities must be considered when using chironomid mouthpart deformities as an index of environmental degradation.
Caged mussels and semipermeable membrane devices as indicators of organic contaminant uptake in dorchester and duxbury bays, Massachusetts
Authors: Peven Carole S. , Uhler Allen D. , Querzoli Francis J. 
Published: March 2010

Abstract
An experiment to measure organic contaminant depuration by the blue mussel (Mytilus edulis) was carried out by transplanting mussels in stainless steel cages from a known contaminated site in Dorchester Bay, Massachusetts to a documented clean site in Duxbury Bay, Massachusetts approximately 30 nmi south of the original collection site. A parallel contaminant uptake experiment was performed in which mussels from Duxbury Bay were collected and deployed in similar cages in Dorchester Bay. The bivalves were collected from each transplant site at set intervals over a period of 95 days to monitor the rates and selectivity of depuration and uptake, respectively, of polynuclear aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and chlorinated pesticides. In a related study, semipermeable membrane devices (SPMD: polyethylene bags) containing the lipid material triolein were deployed in Dorchester Bay and collected at the same frequency as the caged mussels to evaluate their effectiveness as models for estimating bioconcentration of target organic contaminants. At the Duxbury site, results suggest that the caged mussels depurated contaminants within 68 days to levels found in native animals at the site. At the Dorchester site, bivalves concentrated the contaminants to a level similar to the native M. edulis. PCB and DDT uptake rates were found to be similar between caged mussels and SPMDs; PAH uptake by the SPMDs was initially lower than by transplanted bivalves. PCB and PAH assemblages were noticeably different between bivalves and SPMDs deployed at the same site.
Estrogenic activity of surfactants and some of their degradation products assessed using a recombinant yeast screen
Authors: Routledge Edwin J. , Sumpter John P. 
Published: March 2010

Abstract
An estrogen-inducible screen was developed in yeast (Saccharomyces cerevisiae) in order to assess whether surfactants and their major degradation products are estrogenic. The DNA sequence of the human estrogen receptor (hER) was integrated into the yeast genome, which also contained expression plasmids carrying estrogen-responsive sequences (ERE) controlling the expression of the reporter gene lac-Z (encoding the enzyme β-galactosidase). Thus, in the presence of estrogens, β-galactosidase is synthesized and secreted into the medium, where it causes a color change from yellow to red. This recombinant strain was used to determine whether representatives of major surfactant classes and some of their principal degradation products possess estrogenic activity. The results were compared to the effects of the main natural estrogen 17β-estradiol. None of the parent surfactants tested possessed estrogenic activity. However, one class of surfactants, the alkylphenol polyethoxylates, degrade to persistent metabolites that were weakly estrogenic. Another group of degradation products, the sulfophenyl carboxylates, which are derived from the biodegradation of linear alkylbenzene sulfonates, do not appear to possess estrogenic activity.
Predicting relative toxicity and interactions of divalent metal ions: Microtox® bioluminescence assay
Authors: Newman Michael C. , McCloskey John T. 
Published: March 2010

AbstractBoth relative toxicity and interactions between paired metal ions were predicted with least-squares linear regression and various ion characteristics. Microtoxr̀ 15 min EC50s (expressed as free ion) for Ca(II), Cd(II), Cu(II), Hg(II), Mg(II), Mn(II), Ni(II), Pb(II), and Zn(II) were most effectively modeled with the constant for the first hydrolysis (KH for Mn+ + H2O → MOHn-1 + H+) although other ion characteristics were also significant in regression models. The [log KH] is correlated with metal ion affinity to intermediate ligands such as many biochemical functional groups with O donor atoms. Further, ordination of metals according to ion characteristics, e.g., [log KH], facilitated prediction of paired metal interactions. Pairing metals with strong tendencies to complex with intermediate or soft ligands such as those with O or S donor atoms resulted in strong interactions.
Effects of spatial and temporal variation of acid-volatile sulfide on the bioavailability of copper and zinc in freshwater sediments
Authors: Besser John M. , Ingersoll Christopher G. , Giesty John P. 
Published: March 2010

Abstract
Variation in concentrations of acid-volatile sulfide (AVS) in sediments from the upper Clark Fork River of Montana, USA, was associated with differences in bioaccumulation of Cu and Zn and growth of larvae of the midge, Chironomus tentans. Growth of midge larvae was significantly greater and bioaccumulation of Cu was significantly less in surface sections (0–3 cm depth) of sediment cores, which had greater concentrations of AVS and lesser ratios of simultaneously extracted metals to AVS (SEM:AVS ratios) than in subsurface sediments (6–9 cm). Concentrations of AVS were significantly less in sediments incubated with oxic overlying water for 9 weeks than in the same sediments incubated under anoxic conditions. Bioaccumulation of Cu differed significantly between incubation treatments, corresponding to differences in concentrations of AVS and SEM:AVS ratios, although midge growth did not. Bioaccumulation of Zn did not differ significantly between depth strata of sediment cores or between incubation treatments. When results from the two sets of bioassays were combined, bioaccumulation of Cu and Zn, but not growth, was significantly correlated with SEM:AVS ratios and other estimates of bioavailable metal fractions in sediments. Growth of midge larvae was significantly correlated with bioaccumulation of Zn, but not Cu, suggesting that Zn was the greater contributor to the toxicity of these sediments. Assessments of the toxicity of metal-contaminated freshwater sediments should consider the effects of spatial and temporal variation in AVS concentrations on metal bioavailability.
Toxicity and bioaccumulation of selenium to a three-trophic level food chain
Authors: Dobbs Michael G. , Cherry Donald S. , Cairns John 
Published: March 2010

Abstract
Three species, Chlorella vulgaris, Brachionus calyciflorus, and Pimephales promelas, were exposed to selenate for 25 d in a three-trophic level test system. The organisms were linked in a continuous flow-through system in separate vessels, with each organism feeding on the trophic level below it. These organisms were continually exposed for 25 d to 0, 110.3, 207.7, and 396.1 μg/L total recoverable selenium (Se) from selenate in natural creek water supplemented with nutrients to sustain algal growth. In an initial algal screening test, growth rates were reduced at 81.7 and 1,053.7 μg/L, with no effect at 8.5 μg/L. In the trophic test, algal populations showed evidence of reduced growth rates at 207.7 and 386.1 μg/L, but not at 110.3 μg/L. Rotifer population standing crop (measured as dry weight) was significantly reduced at 207.7 and 396.1 μg/L by day 4, and declined to below detection by day 7 at these treatments. Fathead minnow growth was impaired after 7 d at the 207.7 and 396.1 μg/L levels, with 100% mortality by day 16. A reduction in rotifers and fish biomass was also apparent at the 110.3 μg/L level after day 20. The amount of Se in whole organisms was measured throughout the experiment. Bioconcentration factors were found to be dependent on the species, treatment level, and length of exposure period, and they ranged between 100 and 1,000.
Sorption of an alcohol ethoxylate surfactant to natural sediments
Authors: Cano Manuel L. , Dorn Philip B. 
Published: March 2010

Abstract
U.S. consumer and industrial use of surfactants results in down the drain disposal and release after treatment in septic fields or sewage plants. Effluent may contain limited concentrations of surfactant, which may remain in receiving waters, and this residual surfactant could become associated with bottom sediments. To assess this phenomenon, we have examined the sorption of a radiolabeled alcohol ethoxylate (C15 alcohol with an average of 9 moles of ethylene oxide per mole of alcohol) to natural sediments under sterile conditions to assure that the surfactant was not biodegraded. Control experiments comparing sterilized systems with systems including 1% formalin indicated that formalin could be included in the sediment/surfactant/water mixture to prevent surfactant biodegradation yet not interfere in the sorption process. Four sediments with 0.3–2.2% organic carbon content were used in this study to determine the effect of various sediment properties on the sorption process. Equilibrium sorption was established in 2–4 h. The equilibrium sorption isotherms were determined to be nonlinear and described by the Freundlich model, and distribution ratios (ratio of surfactant concentration on sediment to aqueous concentration) at 1 mg/L surfactant ranged from 350 to 2,100 L/kg. The amount of sorption was better correlated to the percent clay content of the sediment than to the percent organic carbon content of the sediment.