bluuebunny/crossref_metadata_2025_split huggingface dataset:
An evaluation of freshwater mussel toxicity data in the derivation of water quality guidance and standards for copper
Authors: March Ferrella A. , Dwyer F. James , Augspurger Tom , Ingersoll Christopher G. , Wang Ning , Mebane Christopher A. 
Published: September 2007

Abstract
The state of Oklahoma has designated several areas as freshwater mussel sanctuaries in an attempt to provide freshwater mussel species a degree of protection and to facilitate their reproduction. We evaluated the protection afforded freshwater mussels by the U.S. Environmental Protection Agency (U.S. EPA) hardness-based 1996 ambient copper water quality criteria, the 2007 U.S. EPA water quality criteria based on the biotic ligand model and the 2005 state of Oklahoma copper water quality standards. Both the criterion maximum concentration and criterion continuous concentration were evaluated. Published acute and chronic copper toxicity data that met American Society for Testing and Materials guidance for test acceptability were obtained for exposures conducted with glochidia or juvenile freshwater mussels. We tabulated toxicity data for glochidia and juveniles to calculate 20 species mean acute values for freshwater mussels. Generally, freshwater mussel species mean acute values were similar to those of the more sensitive species included in the U.S. EPA water quality derivation database. When added to the database of genus mean acute values used in deriving 1996 copper water quality criteria, 14 freshwater mussel genus mean acute values included 10 of the lowest 15 genus mean acute values, with three mussel species having the lowest values. Chronic exposure and sublethal effects freshwater mussel data available for four species and acute to chronic ratios were used to evaluate the criterion continuous concentration. On the basis of the freshwater mussel toxicity data used in this assessment, the hardness-based 1996 U.S. EPA water quality criteria, the 2005 Oklahoma water quality standards, and the 2007 U.S. EPA water quality criteria based on the biotic ligand model might need to be revised to afford protection to freshwater mussels.
Risk assessment of water quality in three North Carolina, USA, streams supporting federally endangered freshwater mussels (unionidae)
Authors: Ward Sara , Augspurger Tom , Dwyer F. James , Kane Cindy , Ingersoll Christopher G. 
Published: September 2007

Abstract
Water quality data were collected from three drainages supporting the endangered Carolina heelsplitter (Lasmigona decorata) and dwarf wedgemussel (Alasmidonta heterodon) to determine the potential for impaired water quality to limit the recovery of these freshwater mussels in North Carolina, USA. Total recoverable copper, total residual chlorine, and total ammonia nitrogen were measured every two months for approximately a year at sites bracketing wastewater sources and mussel habitat. These data and state monitoring datasets were compared with ecological screening values, including estimates of chemical concentrations likely to be protective of mussels, and federal ambient water quality criteria to assess site risks following a hazard quotient approach. In one drainage, the site-specific ammonia ecological screening value for acute exposures was exceeded in 6% of the samples, and 15% of samples exceeded the chronic ecological screening value; however, ammonia concentrations were generally below levels of concern in other drainages. In all drainages, copper concentrations were higher than ecological screening values most frequently (exceeding the ecological screening values for acute exposures in 65–94% of the samples). Chlorine concentrations exceeding the acute water quality criterion were observed in 14 and 35% of samples in two of three drainages. The ecological screening values were exceeded most frequently in Goose Creek and the Upper Tar River drainages; concentrations rarely exceeded ecological screening values in the Swift Creek drainage except for copper. The site-specific risk assessment approach provides valuable information (including site-specific risk estimates and ecological screening values for protection) that can be applied through regulatory and nonregulatory means to improve water quality for mussels where risks are indicated and pollutant threats persist.
Extraction and bioanalysis of the ecotoxicologically relevant fraction of contaminants in sediments
Authors: Puglisi Edoardo , Murk Albertinka J. , van den Berg Hans J. , Grotenhuis Tim 
Published: September 2007

AbstractAssessments of the risk connected to the contamination of soils and sediments should rely on a multidisciplinary approach based on both chemical and biological techniques (i.e., the sum of exposure and effects assessment). The dioxin-responsive, chemical-activated luciferase expression (DR-CALUX) bioassay is widely applied for evaluation of the toxicity of sediments after an exhaustive extraction of the contaminants, and results are used for risk assessment purposes. Approaches based on total extraction of contaminants do not take into account the importance of bioavailability and aging processes, thus leading to possible overestimations of risk. In the present work, an approach based on nonexhaustive extraction techniques in combination with an in vitro reporter gene assay was tested on sediment samples contaminated with dioxins, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and other xenobiotics. Tenax and hydroxypropyl-β-cyclodextrin (HPCD) extractions over time were carried out to determine the bioavailable fractions, whereas the residual fractions were determined by means of a microwave-assisted exhaustive extraction. For both fractions, contaminant concentrations were quantified by gas chromatography-mass spectrophotometry, and the toxic potency was determined by the DR-CALUX assay. Assessments of bioavailable fractions of PCBs by Tenax and HPCD gave comparable results and showed that after several years of aging, a considerable fraction (38–70% of the total content for different PCBs) is still available and ecotoxicologically relevant. Coupling of nonexhaustive extraction and bioanalyses leads to a more realistic and, generally, much lower estimated risk for the toxicity of the extracts as compared to commonly adopted exhaustive techniques.
Spatial and temporal evaluation of metal concentrations in soils and sediments from new orleans, louisiana, USA, following hurricanes Katrina and Rita
Authors: Abel Michael T. , Presley Steven M. , Rainwater Thomas R. , Austin Galen P. , Cox Stephen B. , McDaniel Les N. , Marsland Eric J. , Leftwich Blair D. , Anderson Todd A. , Kendall Ronald J. , Cobb George P. 
Published: September 2007

Abstract
During January 2006, soil and sediment samples from 75 sites in the New Orleans (LA, USA) area were collected and tested for 26 inorganic elements. The study design was intended to provide a spatial pattern of metal concentrations within the city following hurricanes Katrina and Rita. The sampling design included four transects that traversed the city in a north–south direction and three transects that traversed the city in an east–west direction. Contaminant concentrations were determined at multiple sites within each transect and compared to U.S. Environmental Protection Agency soil screening criteria pertaining to human health. Concentrations of Pb and As exceeded the criteria indiscriminately throughout the city. Of the 75 sites, 14 (19%) exceeded the soil screening criteria for Pb, and 73 (97%) exceeded the criteria for As. Forty-three of the 75 sites coincided with a previous sampling event in October 2005. Metal concentrations were evaluated for temporal comparisons using a pair sampled t test. Arsenic concentrations differed significantly over time, but Pb concentrations did not.
Use of the australian crimson-spotted rainbowfish (Melanotaenia fluviatilis) as a model test species for investigating the effects of endocrine disruptors
Authors: Pollino Carmel A. , Georgiades Eugene , Holdway Douglas A. 
Published: September 2007

Abstract
Few studies have investigated the potential reproductive effects of toxicants on Australian freshwater fish species. The present study uses the Australian rainbowfish (Melanotaenia fluviatilis) as a model for testing the potential effects of 17β-estradiol. Groups of reproductively active rainbowfish were exposed to waterborne 17β-estradiol (control, carrier control, and 30, 100, 300, and 1,000 ng/L) for 3- and 14-d periods. Biomarkers of both low ecological relevance (plasma estradiol and testosterone, phosphoprotein, γ-glutamyltranspeptidase [GTP]) and high ecological relevance (egg counts, hatchability, larval lengths, histopathology) were measured and the relationships between these examined. Relative to the controls, exposed female rainbowfish had a decline in plasma estradiol. An increase in phosphoprotein (vitellogenin) also was observed after exposure to 1,000 ng/L after 3 d, and histological examination of the gonads showed an increase in oocyte atresia at 1,000 ng/L on days 3 and 14. Changes in egg production were observed at 300 and 1,000 ng/L. No changes were detected to egg hatchability and larval lengths of offspring. Although there were no changes in male rainbowfish plasma testosterone or the histological organization of testes, levels of phosphoprotein increased and GTP activities were increased after 3 d of exposure at all test concentrations, but these declined at day 14. The present study demonstrated that, though measurements at the biochemical level were responsive to 17β-estradiol exposure, fewer changes were observed in markers of higher ecological relevance at the exposures concentrations and durations tested.
Can the unit world model concept be applied to hazard assessment of both organic chemicals and metal ions?
Authors: Harvey Colin , Mackay Don , Webster Eva 
Published: September 2007

AbstractA unit world model that has the potential to be used for the hazard assessment of both metal ions and organic chemicals is described and discussed, with an emphasis on the problems that arise when treating metal ions. It is based on the steady-state equilibrium criterion model that is designed to simulate the fate of organic chemicals in a 100,000-km2 region and comprises four well-mixed compartments: Air, water, soil, and sediment. To be applicable to metal ions, modifications are required. The single soil and sediment layers should be replaced by two layers to accommodate aerobic and anaerobic conditions. The more complex and variable partitioning of metals resulting from dependence on pH, redox conditions, ionic oxidation state, and presence of sulfide also must be addressed, but preferably in a separate geochemical model, because these factors can result in nonlinearity. For metals, a dynamic as well as a steady-state model is desirable. It is shown that the resulting model can be applied to both organics and metals. Rather than seeking to apply the hazard criterion of persistence to metal ions, the model can be used to deduce a critical loading that results in a defined toxic end point, thus integrating the hazard criteria of persistence, toxicity, and possibly, bioaccumulation. This approach is applied illustratively to naphthalene as a typical organic substance and to four environmentally relevant metal ions. Results are discussed and recommendations made for further development. Specifically, the absence of metal degradation can result in large, steady-state quantities in soils and sediments corresponding to residence times of many centuries. Consequently, the dynamic calculations are more relevant for fate assessments of metals over a period of years, and more focus on the aquatic environment is justified.
Validation study of the acute biotic ligand model for silver
Authors: Bielmyer Gretchen K. , Grosell Martin , Paquin Paul R. , Mathews Rooni , Wu Kuen B. , Santore Robert C. , Brix Kevin V. 
Published: September 2007

AbstractAn important final step in development of an acute biotic ligand model for silver is to validate predictive capabilities of the biotic ligand model developed for fish and invertebrates. To accomplish this, eight natural waters, collected from across North America, were characterized with respect to ionic composition, pH, dissolved organic carbon, and sulfide. Tests were conducted with the cladoceran Ceriodaphnia dubia (48-h static) and the fish Pimephales promelas (96-h static renewal) to determine the concentrations causing lethality to 50% of the organisms (LC50s) for silver in each of these waters. Overall, the biotic ligand model adequately predicted silver toxicity to C. dubia; however, in some cases, predicted LC50 values exceeded measured values. The accuracy of the biotic ligand model predictions was less convincing for silver toxicity to P. promelas with pronounced problems in low–ionic strength waters. Another issue was the use of acclimated organisms in toxicity studies because the biotic ligand model has been developed with the use of a mix of studies with acclimated and nonacclimated test organisms of varying ages and sizes. To evaluate whether effects of acclimation to test waters influence biotic ligand model predictions, a subset of the natural waters were also tested with P. promelas that had been acclimated to the natural water for 7 d before testing. These experiments revealed no differences in toxicity between acclimated and nonacclimated P. promelas. To determine the influence of organism size, which has been previously correlated to Na+ turnover and acute silver toxicity across multiple species, Na+ and Cl− influx rates were measured in P. promelas of different sizes. Our results show that Na+ and Cl− influx rates were inversely related to fish mass and positively correlated with silver sensitivity.
Dynamics of benazolin under the influence of degrading maize straw in undisturbed soil columns
Authors: Berns Anne E. , Schnitzler Frauke , Drewes Norbert , Vereecken Harry , Burauel Peter 
Published: September 2007

Abstract
The effect of organic carbon amendment on the fate of benazolin was investigated in undisturbed soil columns. The soil columns were obtained from three different soil types located in three different regions with different crop production regimes. All soils were operated in a normal crop production regime, and one of the soils was additionally operated in low and high crop production regimes. Two experimental setups were conducted, one using [14C]maize straw and nonlabeled benazolin and one using nonlabeled maize straw and [14C]benazolin. The column experiments with [14C]maize straw showed that the residual crop residues remained mainly in the top layer. Benazolin and its metabolites showed a higher retention in columns that were amended with maize straw compared to column without amendment. The production regimes of the soils did not influence the behavior of benazolin. The effect of maize straw incorporation on the translocation and degradation of benazolin could well be caused by a change in the soil microbial activity, leading to an enhanced degradation of benazolin and producing metabolites exhibiting a sorption behavior different from the parent.
An individual-based approach to model spatial population dynamics of invertebrates in aquatic ecosystems after pesticide contamination
Authors: Van den Brink Paul J. , (Hans) Baveco J. M. , Verboom Jana , Heimbach Fred 
Published: September 2007

Abstract
In the present study we present a population model (Metapopulation model for Assessing Spatial and Temporal Effects of Pesticides [MASTEP]) describing the effects on and recovery of the waterlouse Asellus aquaticus after exposure to a fast-acting, nonpersistent insecticide as a result of spray drift in pond, ditch, and stream scenarios. The model used the spatial and temporal distribution of the exposure in different treatment conditions as an input parameter. A dose–response relation derived from a hypothetical mesocosm study was used to link the exposure with the effects. The modeled landscape was represented as a lattice of 1- by 1-m cells. The model included processes of mortality of A. aquaticus, life history, random walk between cells, density dependence of population regulation, and, in the case of the stream scenario, medium-distance drift of A. aquaticus due to flow. All parameter estimates were based on expert judgment and the results of a thorough review of published information on the ecology of A. aquaticus. In the treated part of the water body, the ditch scenario proved to be the worst-case situation, due to the absence of drift of A. aquaticus. Effects in the pond scenario were smaller because the pond was exposed from one side, allowing migration from the other, less contaminated side. The results of the stream scenario showed the importance of including drift for the population recovery in the 100-m stretch of the stream that was treated. It should be noted, however, that the inclusion of drift had a negligible impact on numbers in the stream as a whole (600 m).
A noninvasive test of exposition to toxicants: Quantitative analysis of cytochrome P4501A expression in fish scales
Authors: Quirós Laia , Raldúa Demetrio , Navarro Anna , Casado Marta , Barceló Damià , Piña Benjamin 
Published: September 2007

Abstract
Elevated expression of cytochrome P4501A (CYP1A) is an established biomarker for exposition to a wide range of toxicants, particularly for dioxin and structurally similar compounds. Expression of CYP1A usually is analyzed in internal organs, which involves dissection of the specimen. To avoid unnecessary animal killing, we present here an alternative method based on the monitoring of CYP1A expression in fish scales. Using β-naphthoflavone (BNF; 50 mg/kg body wt, intraperitoneal injection) as inducer in goldfish (Carassius auratus), we monitored levels of CYP1A mRNA both in scales and liver of treated and control specimens. Treatment with BNF resulted in a similar induction of CYP1A gene in both tissues, although scales responded faster (at 8 h after treatment) than liver (between 24 and 48 h). The scale-based test has the unique advantage of allowing sequential testing in the same specimen, which facilitates analysis of the time course of CYP1A induction and allows the study of individual variability. The method implies minimal suffering of the animals, because it only requires removal of a moderate (n = 1–3) number of scales for each time point. This nondestructive, fast, and relatively inexpensive test for toxic exposure therefore is suitable for environmental monitoring and food safety control programs in which specimen preservation is required.
A control chart approach to monitoring and communicating trends in tissue selenium concentrations
Authors: Chapman Peter M. , deBruyn Adrian M. H. 
Published: September 2007

Abstract
A primary aim of monitoring programs is to determine changes relative to background conditions, which typically represent a distribution of values, not a single value, and which may be elevated naturally. Graphical inspection of the statistical distribution of background and subsequent data provides the best means to determine changes over time and the relative significance of those changes based on both their magnitude and trajectory. The control chart approach commonly used in laboratory and product testing is a useful tool that allows for such determinations in a manner that is transparent to both scientists and nonscientists. This approach can be used both with true baseline (i.e., pre-development) data and with operational baseline (i.e., post-development) data and is particularly relevant for monitoring selenium (Se) tissue concentrations.
Activated carbon amendment as a treatment for residual ddt in sediment from a superfund site in San Francisco Bay, Richmond, California, USA
Authors: Tomaszewski Jeanne E. , Werner David , Luthy Richard G. 
Published: September 2007

AbstractPesticide formulators formerly operating at Lauritzen Channel, a portion of San Francisco Bay near Richmond (CA, USA), caused contamination of sediment with dichlorodiphenyltrichloroethane (DDT). The present study evaluated the distribution of residual DDT in channel sediment six years following extensive remedial dredging. High DDT concentrations (up to 252 mg/kg) were found in Young Bay Mud sampled across the channel. Particle analyses showed most of the contamination is contained in the clay/silt sediment fraction, and desorption tests showed that availability is greater for DDT metabolites than parent DDT. The present study examined the feasibility of using activated carbon amendment to sequester DDT from sediment, including an evaluation of reactivated carbon as a less costly alternative to virgin activated carbons. Treatment success of activated carbon amendment to sediment collected from Lauritzen Channel was measured by reductions in aqueous equilibrium concentrations and uptake in semipermeable membrane devices (SPMDs). Four different activated carbons were tested and, after one month of treatment with 3.2 weight % carbon, DDT aqueous equilibrium concentrations were reduced up to 83% and SPMD uptake was reduced up to 91%. Reactivated carbon was comparable with virgin carbons in all tests. Reduction in SPMD uptake of DDT by treatment with 3.2% reactivated carbon increased to 99% after 26 months of treatment. The effectiveness of activated carbon was dependent on the type, size, dose, and contact time. The results show the potential usefulness of activated carbon amendment as a follow-up remedial technology for management of residuals after dredging contaminated sediment.
Contaminant effects on host-parasite interactions: atrazine, frogs, and trematodes
Authors: Koprivnikar Janet , Forbes Mark R. , Baker Robert L. 
Published: September 2007

Abstract
The effects of contaminants on multispecies interactions can be difficult to predict. The herbicide atrazine is commonly used in North America for corn crops, runs off into wetlands, and has been implicated in the increasing susceptibility of larval frogs to trematode parasites. Using experimental challenges with free-living stages of trematodes (cercariae), it was found that Rana sylvatica tadpoles exposed to 30 μg/L of atrazine had significantly higher intensity of parasitism than did larval frogs either not exposed or exposed to 3 μg/L of atrazine. This result could not be explained by high concentrations of atrazine diminishing antiparasite behavior of tadpoles. Furthermore, when tadpoles and cercariae both were exposed to the same concentration of atrazine, either 3 or 30 μg/L, the abundance of formed cysts was not different from the condition in which both were housed at 0 μg/L of atrazine. Atrazine appears to be debilitating to both free-living cercariae and tadpoles. Studies examining relations between parasitism and contaminant levels must account for such combined effects as well as influences on other interacting species (e.g., first intermediate snail hosts).
Nuts
Authors: Young Clyde T. ,   Updated by Staff
Published: September 2007

AbstractNuts, hard‐shelled seeds enclosing a single edible oily kernel, are generally used for human consumption. Nuts may be consumed as shelled whole nuts or, after blanching, roasted. Roasted nuts may be either eaten or ground into nut butters. Peanuts which contain excessive levels of aflatoxin are generally extracted for peanut oil. Production processes are outlined for nut salting, defatting, and the making of peanut butter. With the exception of peanuts, most commercially important nuts are borne on trees. As a whole, nuts have high oil and protein contents and a low percentage of carbohydrate. Approximate composition in terms of amino acid, fatty acid, vitamin and carbohydrate levels are tabulated for selected nuts and nut products. Because of the high oil content of nuts, rancidity is one of the first signs of deterioration in nuts. Optimal storage conditions are discussed as are coatings and antioxidants to delay the onset of rancidity. Non‐edible uses of nuts are as a source of quick drying oils, activated charcoal, dyes, and tannins. Production data are given for the principal edible nuts: almonds, cashews, Brazil nuts, English walnuts, filberts or hazelnuts, macadamia nuts, pecans, and pistachios.