bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioconcentration and depuration of avermectin B1a in the bluegill sunfish
Authors: van Den Heuvel W.J.A. , Halley B.A. , Ku C.C. , Jacob T.A. , Wislocki P.G. , Forbis A.D. 
Published: March 2010

Abstract
A dynamic 42‒d study was conducted to evaluate the bioconcentration of [3H]avermectin B1a in the bluegill sunfish (Lepomis macrochirus). A mean water concentration of 0.099 μg/L was maintained for a 28‒d exposure period. Radioassay throughout the exposure period indicated a gradual uptake of radioactivity that reached steady state at about 10 to 14 d; the day 28 tissue residue values were 6.8, 3.0, and 11 μg/kg, in whole fish, fillet, and viscera, respectively. Following this 28‒d uptake period, fish were placed in control water for 14 d to permit monitoring of elimination of radioactivity. Radioassay indicated 91 to 95% clearance, with the tissue residues dropping by day 14 of the depuration period to 0.32, 0.27, and 0.53 μg/kg, respectively. A one‒compartment kinetic model was used for analysis of the uptake‒depuration data and yielded for whole fish an uptake rate constant of 12 L kg‒1 d‒1, a depuration rate constant of 0.21 d‒1 (t½ of 3.3 d), and a steady‒state residue concentration of 5.5 μg/ kg. The corresponding bioconcentration factor (BCF) for whole fish was 56 L/kg. Uptake and depuration rate data for fillet and viscera were not significantly different (α= 0.05) than the values for whole fish. The BCF values for fillet and viscera were 28 and 84 L/kg, respectively. The data are consistent with rapid depletion of abamectin (and the structurally related anthelmintic ivermectin) from the tissues of other animals (rats, sheep, cattle). Abamectin does not strongly bioconcentrate in aquatic organisms and would not be expected to biomagnify.
Transboundary pollution: Persistent organochlorine pesticides in migrant birds of the Southwestern United States and Mexico
Authors: Mora Miguel A 
Published: March 2010

Abstract
The hypothesis that migratory birds accumulate persistent organochlorine pesticides (POPs) during the winter in Latin America has been prevalent for many years, particularly since 1,1,1-trichloro-2,2–bis(p-chlorophenyl)ethane (DDT) was banned in the United States in 1972. It has been suggested that peregrine falcons (Falco peregrinus), black-crowned night herons (Nycticorax nycticorax), white-faced ibises (Plegadis chihi), various migratory waterfowl and shorebirds, and other avian species accumulate higher concentrations of POPs while on migration or on their wintering grounds in Latin America. Nonetheless, the data obtained thus far are limited, and there is no clear pattern to suggest that such accumulation occurs on a widespread basis. In this review wildlife contaminant studies conducted along the U.S.-Mexico border and throughout Mexico are discussed. The results for the most part seem to indicate that no major accumulation of 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene) (DDE), the most persistent organochlorine compound, has occurred or been reported for most parts of Mexico. The majority of the DDE values in birds from Mexico were similar to those reported in birds from the southwestern United States during the same years. More work needs to be done, particularly in those cotton-producing areas of Mexico where DDT was applied heavily in the past (e.g., Chiapas and Michoacan). Because DDT is still used for malaria control and may still be used in agriculture in Chiapas, this state is probably the one where most migrant species would still be at a significant risk of increased accumulation of DDE and DDT.
Agrochemical use on banana plantations in Latin America: Perspectives on ecological risk
Authors: Henriques William , Jeffers Russel D , Lacher Thomas E , Kendall Ronald J 
Published: March 2010

AbstractDeveloping tropical nations have greatly expanded their agricultural production during the past decade. Substantial areas of tropical ecosystems have been altered to accommodate agriculture. Banana cultivation is responsible for much of this habitat alteration. Substantial use of agricultural chemicals is required to successfully cultivate bananas, and this has raised concern over the effects of these chemicals on workers, wildlife, and tropical environments in general. We review the practice of banana cultivation and address the major chemical inputs to plantations. Numerous cases of pesticide-related health problems in Latin American plantation workers have been documented, and most were attributable to incorrect use and handling. A review of known wildlife-related impacts of agricultural chemicals commonly used in banana plantations raises substantial concerns about the large-scale environmental impacts in tropical terrestrial and aquatic environments. We recommend the application of an environmental risk assessment process to the use of agricultural chemicals on banana plantations. The process should follow the paradigm as outlined by the U.S. Environmental Protection Agency. Such a study would create a precedent for the assessment of environmental risk in the tropics.
Impact of petroleum pollution on aquatic coastal ecosystems in Brazil
Authors: Da Silva Eduardo Mendes , Peso-Aguiar Marlene Campos , De Fátima Teixeira Navarro Maria , De Barros E Azevedo Chastinet Carla 
Published: March 2010

Abstract
Although oil activities generate numerous forms of environmental impact on biological communities, studies of these impacts on Brazilian coastal ecosystems are rare. Results of tests for the content of oil in sediments and organisms indicate a substantially high rate of degradation. Results for uptake of polycyclic aromatic hydrocarbons in bivalves suggested the recent occurrence of oil spills and that these organisms differed in their capabilities to bioconcentrate oil. The mangrove community has suffered constant inputs of oil and has responded with increased numbers of aerial roots, generation of malformed leaves and fruits by plants, and a decrease in litter production. Studies of the impact of oil on rocky shore communities and the toxicity of oil and its by-products to marine organisms have confirmed the results reported in the literature. Presently most of the available studies deal with the macroscopic effects of oil on organisms and have indicated that the nature of oil, climate characteristics, the physical environment, and the structure of the community influence the symptoms of oil contamination in organisms of coastal waters. Longterm studies should be carried out to assess changes in community structure, sublethal effects in populations, and the resilience of contaminated ecosystems.
Organic pollutants in the coastal environment off San Diego, California. 1. Source identification and assessment by compositional indices of polycyclic aromatic hydrocarbons
Authors: Zeng Eddy Y , Vista Cherrie L 
Published: March 2010

Abstract
Samples collected in January and June 1994 from the Point Loma Wastewater Treatment Plant (PLWTP) effluent, Tijuana River runoff, and microlayer, sediment trap, and surface sediment at several locations adjacent to the PLWTP outfall, mouth of the Tijuana River, and San Diego Bay were analyzed in an attempt to identify and assess the sources of hydrocarbon inputs into the coastal marine environment off San Diego. Several compositional indices of polycyclic aromatic hydrocarbons (PAHs), for example, alkyl homologue distributions, parent compound distributions, and other individual PAH ratios, were used to identify the sources of PAHs. Partially due to the decline of PAH emission from the PLWTP outfall, PAHs found in the sea surface microlayer, sediments, and water column particulates near the PLWTP outfall were predominantly derived from nonpoint sources. The sea microlayer near the mouth of the Tijuana River appeared to accumulate enhanced amounts of PAHs and total organic carbon and total nitrogen, probably discharged from the river, although they were in extremely low abundance in the sediments at the same location. Surprisingly, PAHs detected in the microlayer and sediments in San Diego Bay were mainly derived from combustion sources rather than oil spills, despite the heavy shipping activities in the area.
Contaminant concentrations and biomarker response in great blue heron eggs from 10 colonies on the upper Mississippi River, USA
Authors: Custer Thomas W , Hines Randy K , Melancon Mark J , Hoffman David J , Wickliffe Jeffrey K , Bickham John W , Martin James W , Henshel Diane S 
Published: March 2010

Abstract
In 1993, great blue heron (Ardea herodias; GBH) eggs were collected from 10 colonies on the upper Mississippi River (UMR). They were then artificially incubated until pipping and analyzed for mercury, selenium, and organochlorines. Livers of embryos were analyzed for hepatic microsomal ethoxyresorufin-O-dealkylase (EROD) activity and four measures of oxidative stress. Brains were measured for asymmetry and blood was measured for the coefficient of variation of DNA (DNA CV). Organochlorine concentrations were generally low (geometric mean DDE = 1.3 μg/g wet weight; polychlorinated biphenyl [PCB] = 3.0 μg/g; 2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD] = 11.5 pg/g). Eggshell thickness was negatively correlated with DDE concentrations. Mercury (geometric mean = 0.8 μg/g dry weight) and selenium (3.1 μg/g dry weight) concentrations in GBH eggs were within background levels. EROD activity was not correlated with total PCBs, TCDD, or toxic equivalents (TEQs), based on the relative contribution of individual PCB congeners, dibenzodioxins (PCDDs), and dibenzofurans (PCDFs) to total calculated TEQs. Three of the four measures of oxidative stress were correlated with mercury concentrations. Twenty of 43 (47%) embryo brains were asymmetrical and the embryos with asymmetrical brains had higher EROD concentrations in the liver and higher DNA CV in the blood than embryos with symmetrical brains.
Accumulation of seleno-amino acids in legume and grass plant species grown in selenium-laden soils
Authors: Wu Lin , Guo Xun , Banuelos Gary S 
Published: March 2010

Abstract
Seleno-amino acid accumulation was studied for two legume and two grass species grown in Selenium (Se)-laden soils. An antagonistic relationship was found between the tissue Se-amino acid concentration and the corresponding sulfur-amino acid concentration. This relationship demonstrates a competitive interaction between Se and sulfate at the amino acid synthesis level. The nonsulfur-containing amino acids were not substantially affected by the increase of tissue Se concentration. Sour clover (Melilotus indica L.) was able to accumulate much greater tissue Se concentration than the other three species. Tissue methionine concentration of sour clover, rabbitfoot grass (Polypogon monspeliensis L.), and tall fescue (Festuca arundinacea Schreb.) was not significantly affected by the increase of tissue selenomethionine concentration, but a highly significant negative correlation was found in alfalfa (Medicago sativa L.). This discrepancy suggests that a less antagonistic effect on sulfur-amino acids under the increase of Se-amino acid analogues in the tissue might be able to minimize Se toxicity to the plant. Both Se-methylselenocysteine (nonprotein amino acid) and selenomethionine (protein amino acid) accumulated in the plants when grown in Se-laden soils. Possible effects of these Se-amino acids accumulated by plants on animal health should be tested before the plants are used for forage supplementation.
Accumulation and toxicokinetics of fluoranthene in sediment bioassays with freshwater amphipods
Authors: Driscoll Susan Kane , Harkey Gail A , Landrum Peter F 
Published: March 2010

AbstractTwo freshwater amphipods, Hyalella azteca and Diporeia sp., were exposed to sediment spiked with radiolabeled fluoranthene at nominal concentrations of 0.1 (trace) to 1,270 nmol fluoranthene/g dry weight. In two experiments, uptake kinetics and mortality were determined over 30-d exposures. Concentrations of fluoranthene in sediment and pore water were also measured. Mean survival of H. azteca was generally high, greater than 90% after 10 or 16 d, and greater than 74% after 30 d. Mean survival was lower for Diporeia, 14% after a 30-d exposure to the highest sediment concentration in experiment 1, and 53% in experiment 2. Tissue concentrations in Diporeia were as high as 2 to 4 μmol/g wet weight, a body burden that could be expected to result in death by narcosis. Hyalella azteca did not typically accumulate more than 1 μmol/g wet weight, which is consistent with the lower observed mortality. Apparent steady-state biota–sediment accumulation factors (BSAFs, lipid- and organic-carbon-normalized) for sediment concentrations other than trace level tended to be higher for Diporeia (0.345–0.818) than for H. azteca (0.161–0.612). The BSAFs for trace levels tended to be lower for both species (0.045–0.436) in comparison to higher sediment concentrations. For both organisms, the internal concentration based on body residue was a more reliable indicator of toxicity than were equilibrium partitioning predictions.
Evaluation of the effects of dioxin and PCBs onFundulus heteroclituspopulations using a modeling approach
Authors: Munns Wayne R , Black Dianne E , Gleason Timothy R , Salomon Karen , Bengtson David , Gutjahr-Gobell Ruth 
Published: March 2010

AbstractThe U.S. Environmental Protection Agency (EPA) is reevaluating the risks associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin and related chlorinated hydrocarbons (CHCs). Most information currently available concerning CHC toxic action and biological effects focuses on the responses of individual organisms, as opposed to the potential impacts of CHCs on populations, communities, or ecosystems. In support of EPA's reevaluation, survivorship and reproduction data from two previous studies involving the estuarine fish, Fundulus heteroclitus (Linnaeus), exposed as adults to either dioxin or polychlorinated biphenyls (PCBs), were interpreted at the population level using a stage-classified model of F. heteroclitus population dynamics. The studies differed with respect to the route of exposure of the parental stock: dietary exposure to dioxin in the laboratory and natural exposure to PCBs at the New Bedford Harbor, Massachusetts marine Superfund site. The CHC effects documented in these studies were used to modify fertility and survivorship in the population model. The finite population multiplication (growth) rate, estimated using the model, was used as the measure of population-level effect. In both cases, a negative relationship was observed between CHC dose (quantified as dioxin whole-body burden and liver burden of non-ortho- and mono-ortho-substituted PCB congeners) and population growth rate. The dose-response relationships developed in this study provide useful information for assessing the ecological risks of CHCs to estuarine fish populations.
Induction of testis-ova in Japanese medaka (Oryzias latipes) exposed to p-nonylphenol
Authors: Gray Michelle A , Metcalfe Chris D 
Published: March 2010

Abstract
4-Nonylphenol (NP) is a degradation product of nonylphenol polyethoxylates, a major group of nonionic surfactants. When Japanese medaka, Oryzias latipes were exposed from hatch to 3 months of age to aqueous solutions of NP at nominal concentrations of 10, 50, and 100 μg/L, 50% of the male fish in the 50-μg/L treatment and 86% of the males in the 100-μg/L treatment developed testis-ova, an intersex condition characterized by both testicular and ovarian tissue in the gonad. The ratios of males to females in the control treatment (2:1, M:F) and the 100-μg/L NP treatment (1:2, M:F) were also significantly different. The LOAEC for induction of testis-ova at a nominal concentration of 50 μg/L NP is slightly greater than the upper range of concentrations of NP that have been reported in final effluents from municipal sewage treatment plants. Studies on the environmental fate of nonylphenol ethoxylates and degradation products in the aquatic environment are needed to assess the significance of these data in terms of potential reproductive effects in feral fish populations.
A performance assessment of source correlation and weathering indices for petroleum hydrocarbons in the environment
Authors: Whittaker Martin , Pollard Simon J T 
Published: March 2010

Abstract
The source of petroleum contaminants in the environment and the extent to which these contaminants have weathered following deposition can often be determined through an empirical evaluation of oil n-alkanes, isoprenoids (pristane and phytane), and hopane and sterane biomarkers. Common source correlation and weathering indices have been calculated for three sets of oil samples: fresh, 25% (w/w) weathered, and 50% (w/w) physically weathered diesel standards, crude oils from different sources, and a set of representative heavy oils. For the weathered diesel oils, the C18: tricyclic terpanes and n-alkanes: tricyclic terpanes indices varied most significantly with diesel weathering. Awareness of this may be important when these indices are used to assess biotic routes of contaminant dissolution. For the crude oil samples, C18: phytane demonstrated low specificity between the oils. C18: 17α(H),21β(H)-Hopane and n-alkanes: 17α(H),21 β(H)-hopane differentiated between crude oils but would be expected to vary significantly during weathering due to the microbial amenability of the alkane numerators. Pristane: phytane, phytane: 17α, 21β-hopane and tricyclic terpanes: hopanes were considered to be the indices best able to distinguish between oils from different origins, based on these results. 17α(H), 21β(H)-Hopane: 17α(H), 21β(H)-norhopane did not adequately distinguish between the respective crude oil samples. Finally, the relationship between heavy oil composition and the index value was investigated. Here, the values of n-alkanes: 17α(H), 21β(H)-hopane, phytane: 17α(H), 21β(H)-hopane, and tricyclic terpanes: hopanes decreased as the combined total of polar and asphaltene compounds within oil samples increased. This relationship may be useful in assessing the degradation status of petroleum wastes.
Terrestrial isopods—a good choice for toxicity testing of pollutants in the terrestrial environment
Authors: Drobne Damjana 
Published: March 2010

Abstract
Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the digestive glands. These responses are able to provide accurate indications of sublethal toxicity. Toxicity tests with terrestrial isopods could be much more reliable through the use of positive controls. A positive control with a reference toxicant could also be supplemented by a reference endpoint. The most suitable reference endpoint is change of food consumption rate. Toxicity testing with terrestrial isopods is a very promising method for fast, routine, and inexpensive laboratory determination of the relative toxicities of chemicals in the terrestrial environment.
Optimization and performance evaluation of the continuous algal toxicity test
Authors: Chen Chung-Yuan , Lin Kuo-Ching 
Published: March 2010

Abstract
Responses of Selenastrum capricornutum to cadmium in a chemostat are evaluated under various test conditions defined by the nitrogen to phosphorus ratio, phosphate strength, dilution rate, and ethylenediaminetetraacetic acid content. Based on the test results, these parameters were optimized to achieve superior test sensitivity. This continuous system was also modified to allow testing on a weekly basis. The performance of the modified testing technique was evaluated, employing six different metal toxicants. Compared with batch test results reported by other researchers and our own experiment, the continuous test achieved superior sensitivities and reproducibility. The test method presented in this study is believed to be an ideal technique both for research and regulatory purposes.
Biomarker sensitivity for polynuclear aromatic hydrocarbon contamination in two marine fish species collected in Galveston Bay, Texas
Authors: Willett Kristine L , McDonald Susanne J , Steinberg Michael A , Beatty Karla B , Kennicutt Mahlon C , Safe Stephen H 
Published: March 2010

Abstract
The Galveston Bay estuary exhibited a contamination gradient for polynuclear aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons, and the comparative sensitivity of various biomarkers in fish from different bay locations were determined. Two fish species, hardhead catfish (Arius felis) and Atlantic croaker (Micropogon undulatus), were collected from four stations where sediment total PAHs ranged from 68 to &gt;1,000 ng/g. The induction of cytochrome P4501A-(CYP1A-) dependent hepatic ethoxyresorufin-O-deethylase (EROD) activity, CYP1A mRNA levels, or CYP1A immunoreactive protein in hardhead catfish was highly variable in the field-collected fish and in fish dosed with up to 15 mg/kg benzo[a]pyrene (BaP). In contrast, significant differences were seen in biliary concentrations of naphthalene, phenanthrene, and BaP metabolites in hardhead catfish from polluted versus less polluted areas. In croakers taken from the same four Galveston Bay locations, EROD and glutathione S-transferase activities, immunoreactive CYP1A protein, biliary PAH metabolites, and PAH–DNA adducts were higher at the contaminated stations compared with less polluted locations. These studies suggest that the croaker is a good species for monitoring contaminants that induce CYP1A-mediated responses. Biliary PAH metabolites and PAH–DNA adducts were also sensitive indicators of exposure to PAH contamination in both species of fish.
Inhibition of mercury methylation in anoxic freshwater sediment by group VI anions
Authors: Chen Yuan , Bonzongo Jean-Claude J , Lyons W Berry , Miller Glenn C 
Published: March 2010

Abstract
The addition of group VI anions to sediment slurries resulted in the inhibition of the rate of mercury (Hg) methylation. The ranking of inhibition is as follows: tellurate (TeO 2–4) &gt; selenate (TeO 2–4) &gt; molybdate (MoO 2–4) &gt; tungstate (WO 2–4). In sediment slurries treated with TeO 2–4 and SeO 2–4, methylmercury (MeHg) formation was significantly inhibited (p &lt; 0.05) at the concentrations &gt;50 nM of TeO 2–4 and &gt;270 nM of SeO 2–4, while the significant inhibition (p &lt; 0.05) of Hg-methylation by MoO 2–4 and WO 2–4 was observed in slurries spiked at final concentrations ≥100 μM and ≥700 μM, respectively. Increasing the sulfate (SO 2–4) concentration while using fixed concentrations of inhibitors led to the partial reestablishment of some MeHg production in WO 2–4-treated slurries, whereas, no such significant change was noticed in sediment slurries treated with MoO 2–4 and TeO 2–4. These observations suggested that WO 2–4 inhibits Hg methylation by a competitive mechanism, while MoO 2–4 and TeO 2–4 are noncompetitive inhibitors. Selenate and SO 2–4 showed a qualitatively similar effect on Hg methylation at concentrations tested, in that each showed stimulation at low concentrations and inhibition at high concentrations. The depression of MeHg formation by group VI anions was not accompanied by an inhibition of general microbial activity, suggesting that only particular microorganisms, such as sulfate-reducing bacteria, are responsible for Hg methylation. Finally, in the concentration ranges encountered in most natural aquatic environments, the inhibition of MeHg production by group VI anions is unlikely, except in systems where those elements are found in anomalously high concentrations.