bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytotoxicity studies withLactuca sativain soil and nutrient solution
Authors: Hulzebos E.M. , Dirven-Van Breemen E.M. , van Dis W.A. , Herbold H.A. , Hoekstra J.A. , Baerselman R. , van Gestel C.A.M. , Adema D.M.M. , Henzen L. 
Published: March 2010

AbstractThe toxicity of 76 priority pollutants to lettuce (Lactuca sativa) was determined in soil and in nutrient solution. In the first case a static and in the latter a semistatic exposure was established Volatile and easily degradable compounds had high EC50 values in soil (&gt; 1,000 μg/g). In nutrient solution, however, several of these compounds were rather toxic. Quantitative structure-activity relationships (QSARs) relating EC50 values to log Kow could be described for the toxicity in nutrient solution. Generally, the toxicity of the compounds increased with increasing lipophilicity. Deviations were (partly) caused by reactivity (N-containing compounds, double bonds in compounds), low lipophilicity (log Kow values &lt; 1), and EC50 values close to solubility. To relate toxicity in soil and nutrient solution, soil EC50 values were recalculated to values in the soil pore water using calculated adsorption coefficients. Estimated pore-water EC50 values showed a good correlation with values determined in nutrient solution but were not equal to these values. The differences can be attributed to differences in exposure (static vs. semistatic).
Effects of sediment-bound bifenthrin on gizzard shad and plankton in experimental tank mesocosms
Authors: Drenner Ray W. , Hoagland Kyle D. , Smith J. Durward , Barcellona Wayne J. , Johnson Philip C. , Palmieri Mark A. , Hobson James F. 
Published: March 2010

AbstractWe examined the effects of bifenthrin, a synthetic pyrethroid insecticide, on gizzard shad (Dorosoma cepedianum) and plankton in an 8-d experiment using 16 outdoor tank mesocosms (5.5 m3). The replicated design included six treatments of sediment-bound bifenthrin (0-7,750 ng/L), a sediment-free control treatment, and a fish-free control treatment (with untreated sediment). The 8-d LC50s for gizzard shad were 521 and 207 ng/L, using bifenthrin concentrations in water 1 h after addition and average concentrations during the study, respectively. In the presence of bifenthrin, gizzard shad exhibited abnormal stress behaviors, including swimming slowly, gulping near the water surface, opercle flaring, and head shaking. Bifenthrin significantly reduced copepod nauplii density and turbidity, increased rotifer density and Secchi depth, and affected chlorophyll.
Screening of isolates and strains of Rhizobium leguminosarum biovar Trifolii for heavy metal resistance using buffered media
Authors: Chaudri Amar M. , McGrath Steve P. , Giller Kenneth E. , Angle J. Scott , Chaney Rufus L. 
Published: March 2010

Abstract
The computer program GEOCHEM-PC was used to calculate the metal ion activities of Cu, Zn, Cd, and Ni in defined media amended with various metal ion buffers at pH 6.6 or 6.0 so that the lowest-observed-effect concentrations (LOECs) of these metals to isolates and strains of Rhizobium leguminosarum biovar trifohi could be determined. Strains from the U.S. Department of Agriculture (USDA) Beltsville (MD) Rhizobium culture collection were generally more tolerant of the metals than any of the isolates from the sludge-treated soil (S-isolates) and those from farmyard manure-treated soil (F-isolates), although the S- were more metal resistant than the F-isolates. All isolates and strains, however, tolerated much larger concentrations in the buffered systems than those found in the solutions of soils from which they originated. Copper toxicity, using iminodiace-tate (IDA), occurred for the F- and S-isolates and USDA strains at concentrations of 16, 47, and 430 μg ml−1, respectively, corresponding to predicted ion activities of 0.002, 0.006, and 0.06 μg ml−1, respectively. The Zn LOECs for the F- and S-isolates, without a buffer, occurred at concentrations of 47 and 207 μg ml−1, respectively, corresponding to predicted ion activities of 37 and 157 μg ml−1, respectively. No toxicity occurred when nitrilotriacetate was used for Cd up to concentrations of 356 μg ml−1 (Cd ion activity of 2.6 μg ml−1). Nickel concentrations up to 0.6 μg ml−1 had no effect with ethylene-bis(oxyethylenenitrilo)tetraacetate (EGTA; Ni ion activity of 0.006 μg ml−1) and up to 186 μg ml−1 with IDA (Ni ion activity of 11 μg ml−1).
Impact of hexazinone and metsulfuron methyl on the zooplankton community of a boreal forest lake
Authors: Thompson D.G. , Holmes S.B. , Wainio-Keizer K. , Macdonald L. , Solomon K.R. 
Published: March 2010

Abstract
The impact of hexazinone and metsulfuron methyl herbicides on the zooplankton community of a typical boreal forest lake was investigated using in situ enclosures and a replicated multiple-treatment-level experimental design. Concentration-dependent reductions of zooplankton abundance in response to hexazinone treatment were readily apparent, whereas metsulfuron methyl generated only marginal effects. Field-based, nonlinear regression estimates of EC50 (&lt;6.0 mg L−1) for hexazinone-induced reduction of zooplankton abundance suggest that abundance of various zooplankton taxa may be expected following chronic exposure to environmentally realistic concentrations of this herbicide (i.e., approximately 1 mg L−1). Time to recovery was proportional to exposure level, with definite recovery observed at the 0.01- and 0.1-mg L−1 concentrations of hexazinone. The reduced magnitude of impact, as well as the relative timing of response and recovery in the zooplankton as compared to the phytoplankton community, was consistent with the postulate that hexazinone effects were secondary in nature, resulting indirectly from reductions in phytoplankton biomass and DO. The data provide evidence to suggest that chronic exposure to hexazinone concentrations approximating 1 mg L1− or above may result in reduced primary productivity in lentic ecosystems, which may in turn cause reductions in zooplankton abundance.
Using QSAR to evaluate phenomenological models for sorption of organic compounds by soil
Authors: Brusseau Mark L. 
Published: March 2010

Abstract
The functional dependencies of equilibrium and nonequilibrium sorption parameters on solute molecular descriptors were analyzed for 29 organic compounds and two soils. Similar correlation patterns were obtained with all three evaluated size/shape descriptors (molecular surface area, van der Waals volume, molecular connectivity). The functional dependencies of equilibrium distribution coefficients on the solute molecular descriptors were analyzed for three systems used as phe-nomenological models of sorption by soil (octanol, reversed-phase HPLC packing material [RPLC], polymer). The correlation patterns exhibited by the three models were compared to those reported for the soil systems. The correlation patterns exhibited by the soil data were similar to the patterns exhibited by the polymer systems and dissimilar to those exhibited by the octanol and RPLC systems. In addition, the correlation pattern between the sorption rate coefficient and molecular connectivity was similar to that between polymer-diffusion coefficients and molecular connectivity. Hence, it appears that the polymer analog may be the most appropriate of the three models for representing both equilibrium and nonequilibrium sorption by soil. Based on these results, the polymer analog is suggested as the phenomenological model of choice for investigating and evaluating the sorption dynamics of low-polarity organic compounds in soil systems.
Degradation azo dyes by environmental microorganisms and helminths
Authors: Chung King-Thom , Stevens S. Edward 
Published: March 2010

Abstract
The degradation of azodyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number of anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascans lumbncoides and the cestode Momezia expansa have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysosporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dyes is proposed and future research needs are discussed.
Relationship between acid volatile sulfide and the toxicity of zinc, lead and copper in marine sediments
Authors: Casas Atina M. , Crecelius Eric A. 
Published: March 2010

Abstract
It has been proposed that acid volatile sulfide (AVS) is an important sediment phase for determining the toxicity of certain trace metals. By evaluating the ratio of the molar quantities of simultaneously extracted metal (SEM) to AVS, the toxicity of metals to organisms in contact with sediment can be predicted. This study examines the role of AVS in predicting the toxicity of zinc, lead, and copper in marine sediments.
Sediment samples were titrated with zinc, lead, and copper and subsequently analyzed for SEM, pore-water (PW) metal, and AVS retention. In most cases, metal was not detected in the pore waters until the AVS was exceeded, suggesting that AVS is an adequate measure of the metal-binding capacity of a sediment. The [SEM]-to-[AVS] ratios were calculated and toxicities predicted for each spiking concentration where [SEM]/[AVS] &gt; 1. A 10-d, flow-through, acute bioassay using the marine poly-chaete Capitella capitata was conducted to examine the prediction of toxicity from the metal titrations and the bioassay sediment chemistry data. In most cases, mortalities occurred as predicted. AVS and the [SEM]-to-[AVS] ratio proved useful as predictors of toxicity for zinc, lead, and perhaps copper. Another tool for predicting metal toxicity in sediments may be the [PW]/LC50 value; in every case where this ratio was &gt;1, mortalities occurred.
Hepatic cadmium, metal-binding proteins and bioaccumulation in bluegills exposed to aqueous cadmium
Authors: Cope W. Gregory , Atchison Gary J. , Wiener James G. 
Published: March 2010

AbstractWe examined sublethal responses of juvenile bluegills Lepomis macrochirus to aqueous cadmium in two 28-d tests (test I, 0.0-8.4 μg Cd per liter; test II, 0.0-32.3 μg Cd per liter) in an intermittent-flow diluter. The experimental design was completely randomized, with two replicates in each of eight treatments (seven Cd exposures and one water control with 25 fish per replicate). Cadmium did not affect the growth of test fish. The mean whole-body concentrations of Cd in exposed fish were 1.8- to 44-fold those in controls in the two tests. Mean concentrations of hepatic nonthionein cytosolic Cd (not bound by metal-binding proteins, MBP) in all Cd treatments greatly exceeded those in controls, and mean concentrations of hepatic MBP in all treatments except one (0.8 μg Cd per liter in test I) exceeded those in controls. Nonthionein cytosolic Cd, hepatic MBP, and whole-body Cd in bluegills were linearly related to exposure concentrations within the range 0 to 20 μg Cd per liter. Much of the total Cd-binding capacity of hepatic MBP per fish was occupied by Cd after the 28-d exposures, although additional Cd-binding capacity remained unoccupied by Cd in fish in all treatments. The mean total Cd-binding capacity of hepatic MBP per fish, which ranged from 1.7 to 14 nmol Cd in test I and from 0.8 to 24 nmol Cd in test II, increased in a concentration-response manner at exposure concentrations below 13 μg/L. Nonthionein cytosolic Cd was the most sensitive indicator of Cd exposure, based on an LOEC of 0.8 μg Cd per liter.
Copper intake and health threat by consuming seafood from copper-contaminated coastal environments in taiwan
Authors: Han Bor-Cheng , Jeng Woei-Lih , Hung Tsu-Chang , Jeng Ming-Shiou 
Published: March 2010

AbstractThe purpose of this paper is to describe the impact of copper pollution on the main aquaculture coast of Taiwan and the potential risk from eating the green oysters cultured along the polluted coast. Our data show that the highest average concentration of copper (2,194 ± 212 μg/g) in oysters was observed in the Erhjin Chi estuary from 1986 to 1990 (after the “green oyster” incident) The copper concentration in both the seawater and the sediment collected along the Erhjin Chi estuary was also the highest in all sampling locations. Copper concentration in oysters collected from Erhjin Chi, Hsiangshan, and Anping from 1988 to 1990 was, respectively, 61, 29, and 22 times higher than that of 10 years ago The potential risk from consuming oysters is relatively higher than that of other seafoods due to the high bioaccumulation of oysters The oysters in the Erhjin Chi estuary had an average concentration of copper of 3,075 ± 826 μg/g during the past three years (1988-1990). The average copper intake from oysters for an adult with 70 kg body weight was 12.6 mg/d The estimate indicated that the average copper intake from the oysters for female individuals is 14 times more than that of international limits. Based on the average value, long-term intake of copper through consumption of oysters cultured along the Erhjm Chi estuary could be critical, especially for some high-risk groups.
Effect of chlorpyrifos on soil microbial activity
Authors: Pozo C. , Martinez-Toledo M. V. , Salmeron V. , Rodelas B. , Gonzalez-Lopez J. 
Published: March 2010

AbstractA study of the effects of the insecticide chlorpyrifos on soil microbial activity was made. Parameters included total bacterial populations, fungi, aerobic N2-fixing bacteria, denitrifying bacteria, nitrifying bacteria, nitrogenase activity, acid and alkaline phosphatases, arylsulfatase, and dehydrogenase. The presence of 2.0, 3.5, 5.0, and 10.0 kg/ha of chlorpyrifos significantly (p &lt; 0.05) decreased aerobic dinitrogen-fixing bacteria and dinitrogen fixation, particularly after a second insecticide treatment The total number of bacteria increased significantly at concentrations of 2.0 to 10.0 kg/ha. Activities of acid and alkaline phosphatases and dehydrogenase significantly decreased initially at concentrations of 2.0 to 10.0 kg/ha, but recovered after 14 d to levels similar to those in control soil without chlorpyrifos. Fungal populations, nitrifying bacteria, and denitrifying bacteria were not affected as a consequence of the addition of the insecticide.
Chlorinated hydrocarbons in early life stages of the common snapping turtle (Chelydra serpentina serpentina) from a coastal wetland on lake Ontario, Canada
Authors: Bishop Christine A. , Lean David R S , Carey John H. , Brooks Ronald J. , Ng Peggy 
Published: March 2010

Abstract
To assess intra-clutch variation in contaminant concentrations in eggs, and to investigate the dynamics of chlorinated hydrocarbon accumulation in embryos of the common snapping turtle (Chelydra serpentina), concentrations of p,p DDE, hexachlorobenzene, trans nonachlor, cis-chlordane, and six PCB congeners were measured in eggs, embryos, and hatchhngs Samples were collected from Cootes Paradise, a wetland at the western end of Lake Ontario, Ontario, Canada The intra-clutch variation in chlorinated hydrocarbon concentrations within four snapping turtle clutches was determined by analyzing the first, last, and middle five eggs oviposited in the nest The first five eggs had the highest mean concentrations of all chlorinated hydrocarbons (wet weight basis), wet weight, and egg diameter On a lipid weight basis, the first five eggs contained the highest concentration of all compounds except total PCBs and cis chlordane The concentration of as chlordane (lipid weight basis) was the only parameter measured that was significantly different among the three sets of eggs At hatching, snapping turtles without yolk sacs contained from 55 2 to 90 5% of the absolute amount of organochlorine compounds measured in the egg at oviposition Eighteen days after hatching, the body burden of PCBs and pesticides decreased to 45 3 to 62 2% of that in the fresh egg The accumulation of organochlorine chemicals in embryonic turtles peaked at or just before hatching and then declined thereafter, which is consistent with trends reported in developing sea turtles, fish, and birds
Evaluation of screening procedures for bioconcentratable organic chemicals in effluents and sediments
Authors: Burkhard Lawrence P. , Sheedy Barbara R. 
Published: March 2010

Abstract
Screening procedures have been developed by the U.S. Environmental Protection Agency (EPA) to isolate and tentatively identify nonpolar organic chemicals in effluent and sediment samples with high potential to form chemical residues in aquatic organisms. The objective of this study was to determine if the sample components tentatively identified by the effluent-and sediment-screening procedures actually form chemical residues in aquatic organisms. This evaluation consisted of analyzing effluent and sediment samples from a field site with discharges from two coke-manufacturing facilities using the screening procedures. Effluent, sediment, crayfish (Decapoda), and sunfish (Lepomis sp.) samples from the field site were also prepared using conventional sample preparation procedures and analyzed for the tentatively identified chemicals (TIDs) reported by the screening procedures. Results of the screening procedures were then compared to the results of the analyses on the samples prepared using the conventional sample preparation procedures. For the effluent-screening procedure, 182 of 183 TIDs in Coke Plant 1 effluent and all of the 7 TIDs in Coke Plant 2 effluent were found in the crayfish, sunfish, and/or sediment samples downstream of the discharges. For the sediment-screening procedure, 92 of 93 TIDs and all of 47 TIDs in sediment samples from two sampling stations downstream of the discharges were found in the crayfish and/or sunfish samples.
Effects of storage time on toxicity of sediments from puget sound, Washington
Authors: Becker D. Scott , Ginn Thomas C. 
Published: March 2010

AbstractThe effects of sediment storage time were determined for three sediment toxicity tests: the amphipod test using Rhepoxynius abronius, the polychaete test using Neanthes sp., and the Microtoxr̀ test using Photobacterium phosphoreum. Sediments were collected from a reference area and a contaminated area in Puget Sound to determine the effects of storage time on each type of sediment. Toxicity comparisons were also made between the two kinds of sediment to simulate the manner in which the data might be analyzed in a regulatory or decision-making context. Sediments were stored at 4°C for as long as 16 weeks. Results of all three toxicity tests varied significantly with storage time for each type of sediment. Amphipod survival generally decreased with storage time, whereas luminescence in the Microtox test and polychaete biomass varied unpredictably. The significance of differences between results for the two sediments varied unpredictably with storage time for the amphipod and Microtox tests. By contrast, differences were consistently significant for all storage times for the polychaete test, primarily because of the large differences in the test response between sediments. These results suggest that effects of storage time are greater for results indicative of low to intermediate levels of toxicity than for results indicative of high levels of toxicity. It is recommended that sediments be tested as soon as possible after field collection to minimize the potential for alterations of toxicity during storage.
Biotransformation of di(2-ethylhexyl)phthalate by rainbow trout
Authors: Barron Mace G. , Albro Phillip W. , Hayton William L. 
Published: March 2010

AbstractThe biotransformation of di(2-ethylhexyl)phthalate (DEHP) was studied in rainbow trout (Oncorhynchus mykiss) following intravascular administration. Methyl-esterified metabolites were identified using rodent-derived standards and nonlinear gradient elution HPLC; metabolites were confirmed by gas chromatography. Similarities between the biotransformation of DEHP by rainbow trout and mammalian species included (a) mono-ethylhexyl phthalate (MEHP) appeared to be the obligatory first step in DEHP metabolism; (b) the phthalate ring was not oxidized; (c) phthalic acid was a minor metabolite; and (d) several metabolites contained multiple oxidations of the 2-ethylhexyl moiety of MEHP. No metabolites unique to rainbow trout were identified. However, fewer oxidized metabolites were identified in rainbow trout than in mammalian species, possibly due to limited mitochondrial metabolism of MEHP in rainbow trout. The amount of biliary MEHP glucuronide after intravascular administration of DEHP was substantially less than reported in rainbow trout exposed to DEHP via the water. Results confirmed that DEHP metabolism in rainbow trout proceeds by initial rapid formation of MEHP, followed by excretion or extensive oxidation by microsomal P450.
Aquatic toxicity variability for fresh- and saltwater species in refinery wastewater effluent
Authors: Bleckmann Charles A. , Rabe Bruce , Edgmon Sheila J. , Fillingame Drew 
Published: March 2010

Abstract
The U.S. Environmental Protection Agency (EPA) has established test requirements for toxicity reduction or toxicity identification evaluations (TR/TIE) of wastewater effluents. Interpretations of test results are complicated by factors other than toxicity when essentially freshwater wastewaters flow into estuaries and the effluent permit requires marine organisms for testing. This paper reports the results of an investigation of potential freshwater surrogate species, and Microtoxr̀, for use in such a TIE. Of the five species tested, mysid shrimp were found to be most sensitive to unidentified toxicants in petroleum refinery wastewater. No strong correlations of this sen0itivity to that of other organisms, or to several wastewater constituents, were identified. The two marine species specified in the effluent permit were more sensitive to the toxicants than were the freshwater species.