bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biochemical biomarkers of pollution in the clam Chamaelea gallina from South-Spanish littoral
Authors: Rodríguez-Ortega Manuel J. , Alhama José , Funes Victoria , Romero-Ruíz Antonio , Rodríguez-Ariza Antonio , López-Barea Juan 
Published: March 2010

Abstract
Fourteen biochemical pollution biomarkers were analyzed in the clam Chamaelea gallina sampled at seven South-Spanish littoral sites at different times in 1999. They included enzymes that regenerate reduced nicotinamide adenine dinucleotide phosphate (NADPH) or maintain the cytosol-reduced (glucose-6-P- and isocitrate dehydrogenases, glutathione reductase), that decompose reactive oxygen species (catalase, superoxide dismutase, glutathione peroxidase), or detoxify glutathione-reactive electrophiles (soluble and microsomal glutathione transferases, glyoxalases II and I). The levels of reduced glutathione, malondialdehyde, and metallothionein and the glutathione redox status were also determined. Clams from Huelva sites with higher contaminant loads and metallothionein levels showed higher antioxidant and glutathione-related activities and a decreased glutathione level, lower malondialdehyde content, and a less oxidized glutathione status. This suggests that clams chronically exposed to contaminants released by Huelva and Guadalquivir Estuaries are better protected from oxidative stress than reference animals. Most biomarkers showed six-month cyclicity with up to threefold amplitudes, further supporting the inverse relationship between antioxidant defenses and oxidative damages. Thus the lower antioxidant defenses in June fit to maximum oxidative damages, whereas the high antioxidant defenses found in March and September through October agree with lower lipid damages and less oxidized glutathione status. The effect of environmental or endogenous factors on this cyclic response is discussed.
Citrate-mediated increase in the uptake of weathered 2,2-bis(p-chlorophenyl)1,1-dichloroethylene residues by plants
Authors: White Jason C. , Kottler Bennett D. 
Published: March 2010

Abstract
Experiments were conducted to determine the ability of citrate to enhance the plant uptake of weathered 2,2-bis(p-chlorophenyl) 1,1-dichloroethylene (p,pǐ-DDE) from soil. Plots containing three rows of clover, mustard, hairy vetch, or rye grass were constructed in soils containing p,pǐ-DDE. On 11 occasions, the rows of each crop received water or sodium citrate (0.005 or 0.05 M). For each crop, there were significant reductions in p,pǐ-DDE concentration in the soil fractions (near root and rhizosphere) closely associated with the plant versus bulk soil. The roots of each crop accumulated 2 to 5 times more of the weathered contaminant (dry wt) than present in the bulk soil. Citrate (0.05 M) increased the concentration of p,pǐ-DDE in the roots of clover, mustard, and hairy vetch by 39% compared with vegetation that received water. In batch desorption studies, the release of weathered p,pǐ-DDE was significantly greater in the presence of 0.05 M citrate than in water. Citrate increased the extracted aqueous concentrations of five metal ions (Al, Fe, Ca, K, Mn) from soil by five- to 23-fold over distilled water. We hypothesize that citrate physically disrupts the soil through chelation of structural metal ions and release of bound humic material, facilitating p,pǐ-DDE availability and uptake by plants.
Effects of handling on heat shock protein expression in rainbow trout (Oncorhynchus mykiss)
Authors: Washburn Barbara Shayne , Moreland Jason J. , Slaughter Ann M. , Werner Inge , Hinton David E. , Sanders Brenda M. 
Published: March 2010

AbstractAs part of an effort to validate the use of heat shock proteins (HSPs) as biomarkers of exposure to and effects of contaminants, we evaluated the effect of two handling regimens on the induction of HSP 60 and 70 in rainbow trout (Oncorhynchus mykiss). Fish were acclimated to laboratory conditions for several weeks before the beginning of the experiment. Fish were then captured by net, placed in a cooler for 1 h while being transported in a truck, returned to their original tanks, then sacrificed 6 to 8 h later. Tricaine methane sulfonate (MS-222) was used during different phases of handling to reduce handling stress. Heat-stressed fish were included in the experiment as a positive control. Muscle, liver, gills, and heart were analyzed for HSP 60 and 70 by immunoblotting. We found no effect of any handling regimen on the induction of HSPs. These findings suggest that the capture and transport of fish for environmental monitoring purposes should not interfere with the use of stress proteins as biomarkers.
Sublethal effects in avocet and stilt hatchlings from selenium-contaminated sites
Authors: Hoffman David J. , Marn Carolyn M. , Marois Katherine C. , Sproul Elaine , Dunne Mary , Skorupa Joseph P. 
Published: March 2010

Abstract
Excess selenium (Se) in the aquatic food chain is embryotoxic and teratogenic to avocets, stilts, and other waterbirds. American avocet (Recurvirostra americana) and black-necked stilt (Himantopus mexicanus) eggs were collected from three sites in the Tulare Lake Basin of California, USA, and hatched in the laboratory. These sites included the Tulare Lake Drainage District-north (TLDD-N, water 2.5 ppb Se), TLDD-south (TLDD-S, water 8.6 ppb Se), and Westfarmers (WF, water 190 ppb Se). Highest egg Se concentrations occurred at WF (geometric mean 31.4 ppm dry wt for avocets and 20.5 ppm dry wt for stilts). Mean egg Se concentrations were 6.7 ppm for avocets and 8.4 ppm for stilts at TLDD-S, and 3.3 ppm for avocets and 2.3 ppm for stilts at TLDD-N. Hatching success and incidence of malformations did not differ among sites, but yolk sac-free hatching weights and bone lengths were less for avocets at the WF site, whereas liver weights and liver to body weight ratios were greater at that site. With increasing Se concentration, oxidative stress was most apparent in avocet hatchlings from WF: hepatic glutathione (GSH) peroxidase activity increased, glucose-6-phosphate dehydrogenase activity decreased, and oxidized glutathione (GSSG) concentration as well as the ratio of GSSG to reduced GSH concentration increased. In stilts, hepatic GSH concentration was lower in WF hatchlings. In conclusion, our findings of Se-impaired embryo growth and hepatotoxicity in avocet hatchlings suggest that oxidative stress observed in hatchlings may be related to these biological effects and may serve as a potential bioindicator of subsequent impaired functions.
Spatial trends and bioaccumulation of organochlorine pollutants in marine zooplankton from the Alaskan and Canadian Arctic
Authors: Hoekstra Paul F. , O'Hara Todd M. , Teixeira Camilla , Backus Sean , Fisk Aaron T. , Muir Derek C. G. 
Published: March 2010

AbstractPlanktonic copepods (Calanus glacialis and C. hyperboreus; n = 37) and water (n = 19) were collected to examine the spatial distribution and bioaccumulation of organochlorine contaminants (OCs) in the Alaskan and Canadian Arctic. The rank order of total OC (σ OC) group concentrations in Calanus samples was toxaphene ≥ σ polychlorinated biphenyls (PCBs) &gt; σ hexachlorcyclohexane (HCH). σ DDT &gt; σ chlordane-related compounds (CHLOR) &gt; σ chlorobenzenes (ClBz). The dominant analyte was α-HCH in all water and zooplankton samples. The most abundant toxaphene congener in water and zooplankton samples was the hexachlorobornane B6-923. Organochlorine contaminant group concentrations in Alaskan zooplankton and water samples were lower than those in samples collected from sites in the eastern Canadian Arctic. Comparison of PCB and toxaphene congener profiles in zooplankton and water samples suggests that biotransformation by cytochrome P-4502B isozymes is low in Calanus, and limited phase I metabolism may occur. The log relationship of bioaccumulation factor (log BAF) versus octanol-water partition coefficient (log Kow) relationship was near 1: 1 for OCs within the log Kow range of 3 to 6. A curvilinear model provided a better relationship between these two variables when OC compounds with log Kow &gt; 6 were included. These results suggest that hydrophobic OCs (log Kow 3-6) in Calanus species are at equilibrium with the water concentrations and that physical partitioning, rather than biotransformation, is the major factor governing OC profiles in marine zooplankton.
Genetic effects of mercury contamination on aquatic snail populations: Allozyme genotypes and DNA strand breakage
Authors: Benton Michael J. , Malott Michelle L. , Trybula Jan , Dean Deborah M. , Guttman Sheldon I. 
Published: March 2010

AbstractAllozyme data and DNA strand break frequencies were compared among populations of Pleurocera canaliculatum from five sites with varying mercury contamination on the North Fork Holston River (NFHR) in southwestern Virginia, USA. Allozyme genotype frequencies for four loci were significantly different between populations from the three most highly contaminated sites and those from two lesser contaminated sites. In addition, heterozygosity at three of these loci was significantly lower in the populations from the most highly contaminated sites. The DNA strand break frequency was significantly correlated to whole-body total mercury concentration in snails from three sites. These data add to the evidence supporting the use of DNA strand breakage as an indicator of chemical contamination and the use of allozyme analysis as a marker of contamination and possible selection for pollution resistance. However, the relationship between contaminant-induced changes in the genetic variation of enzymes of central metabolism and the functionalities upon which selection for resistance may act remain unclear, and mechanisms other than selection for resistance must be considered. Use of enzymes from other biochemical pathways may be appropriate for other species or for those under other chemical pollution pressures.
Environmentally relevant concentrations of ammonium perchlorate inhibit thyroid function and alter sex ratios in developing Xenopus laevis
Authors: Goleman Wanda L. , Carr James A. , Anderson Todd A. 
Published: March 2010

Abstract
Embryos and larvae of the South African frog Xenopus laevis were exposed to ammonium perchlorate (AP) or control medium for 70 d. The dosage levels (59 ppb, 14,140 ppb) bracketed a range of perchlorate concentrations measured in surface waters at the Longhorn Army Ammunition Plant (LHAAP) in Karnack, Texas, USA. The experiment also included a 28-d nontreatment recovery period to assess the reversibility of AP effects. There were no significant effects of AP on mortality or hatching success. There were no effects of AP on developmental abnormalities such as bent/asymmetric tails or edema. Ammonium perchlorate inhibited forelimb emergence, the percentage of animals completing tail resorption, and hindlimb development during the 70-d exposure period. Only the upper AP concentration reduced whole-body thyroxine content, whereas both concentrations caused significant hypertrophy of the thyroid follicular epithelium. Both concentrations of AP caused a skewed sex ratio, significantly reducing the percentage of males at metamorphosis. The effects of AP on metamorphosis and thyroid function were reversed during the 28-d nontreatment recovery period. We conclude that AP inhibits thyroid activity and alters gonadal differentiation in developing X. laevis. These effects were observed at concentrations at or below concentrations reported in surface waters contaminated with ammonium perchlorate, suggesting that this contaminant may pose a threat to normal development and growth in natural amphibian populations.
Influence of metal (Cd and Zn) waterborne exposure on radionuclide (134Cs, 110mAg, and 57Co) bioaccumulation by rainbow trout (Oncorhynchus mykiss): A field and laboratory study
Authors: Ausseil Olivier , Adam Christelle , Garnier-Laplace Jacqueline , Baudin Jean-Pierre , Casellas Claude , Porcher Jean-Marc 
Published: March 2010

AbstractField and laboratory experiments were carried out to assess the influence of Cd and Zn on the contamination levels of 110mAg, 57Co, and 134Cs in rainbow trout. During a four-week prior exposure phase, two fish groups were held in tanks in the Lot River (France) at a reference (&lt;0.05 μg Cd/L and 68 μg Zn/L) and at a polluted site (1.5 μg Cd/L and 152 μg Zn/L). During a subsequent phase, organisms were brought back to the laboratory, where the radionuclide accumulation and depuration were studied for 14 and 7 d, respectively. During this second phase, the water used in the experiments was brought back from the two sites on the Lot River in order to work under the same chemical conditions. The potential effect of chronic exposure to stable metals on several biomarkers has been explored: Plasma analysis indicated the disruption of certain variables linked to the energetic metabolism and to the maintenance of the ionic balance. In contrast, no significant disruption of the measured enzyme activities was observed. With regard to the bioaccumulation of radionuclides, concentrations in fish exposed to metals are much lower than those in fish from the control group. Various hypotheses are proposed to link fish metabolic profiles due to metal exposure to the radiocontamination of organisms.
Investigation of effects of trifluoroacetate on vernal pool ecosystems
Authors: Benesch Jody A. , Gustin Mae S. , Cramer Grant R. , Cahill Thomas M. 
Published: March 2010

Abstract
Trifluoroacetate (CH3COO-, TFA) is a breakdown product of hydrochlorofluorocarbons and hydrofluorocarbons and is released by the heating of Teflon® products. Because of its chemical properties, concentrations in evaporative wetlands are predicted to increase with time. This study focused on assessing the impact of this haloacetic acid on vernal pool soil microbial communities as well as vernal pool and wetland plant species. Microbial respiration for three vernal pool soils and an agricultural soil was not affected by TFA exposures (0, 10, 100, 1,000, and 10,000 μg/L), and degradation of TFA by microbial communities was not observed in soils incubated for three months. Trifluoroacetate accumulated in foliar tissue of wetland plant species as a function of root exposure concentration (100 and 1,000 μg/L TFA), and accumulation was found to stabilize or decrease after the second or third month of exposure. Seeds accumulated TFA as a function of root exposure concentration; however, germination success was not affected. No adverse physiological responses, including general plant health and photosynthetic and conductance rates, were observed for root exposures at the TFA concentrations used in this study. Based on the soils and plant species used in this study, predicted TFA concentrations will not adversely affect the development of soil microbial communities and vernal pool plant species.
Development of the Spray Drift Task force database for aerial applications
Authors: Hewitt Andrew J. , Johnson David R. , Fish John D. , Hermansky Clarence G. , Valcore David L. 
Published: March 2010

Abstract
This article is part of a series describing the development of the Spray Drift Task Force (SDTF) database and its application to agricultural chemical exposure risk assessment modeling. The series describes the development of a large generic database (assuming that active ingredient rate is not a factor affecting physical drift) and its use in estimating spray movement immediately following application by aerial methods. The components of the database are described. In agreement with field trials in the open literature, the database shows that the major variables affecting off-target spray deposition are droplet size, spray release position (boom height and length), and wind speed and direction. In addition, secondary parameters that can affect these variables and drift are also discussed.
Kinetics of polychlorinated biphenyl dechlorination by Hudson River, New York, USA, sediment microorganisms
Authors: Cho Young-Cheol , Sokol Roger C. , Rhee G-Yull 
Published: March 2010

Abstract
The kinetics of polychlorinated biphenyl (PCB) dechlorination by Hudson River (New York, USA) sediment microorganisms were investigated using Aroclor 1242 at 10 concentrations ranging from 0 to 900 ppm (0–11.2 μmol Cl/g sediment). The time course of PCB dechlorination and population growth were determined by congener-specific analysis and the most-probable-number technique, respectively, over a 44-week incubation period. Dechlorination rate (nmol Cl removed/g sediment/d) was a linear function of PCB concentrations similar to the dechlorination of Aroclor 1248 by sediment microorganisms from the St. Lawrence River (New York, USA). However, the rate was much slower, with the linear slope being only 24% that of the St. Lawrence River. The threshold concentration below which no dechlorination occurs was (mean ± standard deviation) 1.06 ±0.18 μmol Cl/g sediment (85±14 ppm), threefold higher than that for the dechlorination of Aroclor 1248. The maximum extent of dechlorination was greater at higher Aroclor concentrations. Dechlorinating microorganisms did not show any significant growth until late in the lag phase of dechlorination, and their maximum was greater at higher initial Aroclor 1242 concentrations. Although dechlorination rates were significantly lower with the Hudson River inoculum, when normalized to the maximum number of dechlorinating organisms, they were not significantly different from those for Aroclor 1248 by St. Lawrence River microorganisms. These results further support the idea that PCB dechlorination is tightly linked to the growth of dechlorinating microorganisms.
Metallothionein-like metal-binding protein in the biomonitor Chaoborus: Occurrence and relationship to ambient metal concentrations in lakes
Authors: Croteau Marie-Noële , Hare Landis , Campbell Peter G. C. , Couillard Yves 
Published: March 2010

Abstract
Larvae of the insect Chaoborus are used to monitor cadmium (Cd) in lakes. We set out to determine if this animal possesses a metallothionein-like protein to which its Cd could be bound and if the concentrations of such a protein are correlated with those of Cd in the insect and in lakewater. To achieve our goals, we collected water and larvae of several Chaoborus species from 10 lakes situated along an environmental Cd gradient. We found that all of the Chaoborus species possess a metallothionein-like protein and that concentrations of the protein and of Cd differed among species. Concentrations of the metallothionein-like protein were directly related to those in Chaoborus and in lakewater. These direct relationships support the use of Chaoborus larvae as a Cd biomonitor.
Effects of contact time on the sequestration and bioavailability of different classes of hydrophobic organic chemicals to benthic oligochaetes (Tubificidae)
Authors: Kraaij Rik H. , Tolls Johannes , Sijm Dick , Cornelissen Gerard , Heikens Alex , Belfroid Angelique 
Published: March 2010

AbstractDifferences in bioavailability of hydrophobic organic compounds (HOC) to benthic deposit feeders have been related to differences in sediment-HOC contact time and sequestration (formation of slowly desorbing fractions) status. As a consequence, it was postulated that contact time and/or sequestration should be incorporated into risk assessment. In the present study, we investigated the effect of contact time on the bioavailability and sequestration of different classes of HOC. For this purpose, we simultaneously measured the steady-state accumulation into benthic oligochaetes (Tubificidae) and the distribution over rapidly and slowly desorbing fractions in laboratory-contaminated sediment at different contact times. The decrease in rapidly desorbing fractions (Frap) of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and 2,2-bis (4-chlorophenyl)-1,1-dichloroe-thylene (p,p′-DDE) after a contact time of 959 d did not exceed a factor of 1.2. Similarly, the reduction in bioavailability was a factor of 2.3 at maximum, indicating that long contact times do not necessarily result in pronounced bioavailability reduction. For chlorobenzenes, the bioavailability was reduced with a factor of 5 to 18. This decrease corresponded with a pronounced reduction in Frap, which was attributed to losses of rapidly desorbing compounds. Over 75% of the variation in biota-to-sediment accumulation factors (BSAFs) of the PAHs and chlorobenzenes at the three contact times could be explained by differences in Frap. The present study provides evidence of a relationship between sequestration status and bioavailability of HOC to benthic deposit feeders.
Changes in the potential quantum yield of photosystem II and the integrity of cell membranes relative to the elemental content of the epilithic desert lichen Ramalina maciformis
Authors: Garty Jacob , Tamir Orly , Cohen Yehudith , Lehr Haya , Goren Ayana I. 
Published: March 2010

Abstract
The present study used the epilithic fruticose lichen Ramalina maciformis to investigate the occurrence of mineral elements, including heavy metals, at a distance of up to 50 km from the industrial region in Ramat Hovav in the Negev Desert, Israel. The major objective of this study was an analytical comparison of elemental content and physiological parameters of lichen vitality, apart from a test of the applicability of this specific lichen in investigations of air pollution. The Ca, Cr, Cu, K, Mg, Na, Pb, S, Sr, and Zn content of thalli from the unpolluted Tellalim site collected in August 1997, transferred to 24 biomonitoring sites, and retrieved in April 1998 was analyzed in comparison with the following parameters: The potential quantum yield of photosystem II (PSII), and the integrity of cell membranes. Transplanted thalli in several sites at Ramat Hovav accumulated large amounts of most of the elements. The K content of the transplants located in the polluted sites indicated a leakage of this element, because this content was lower than that of thalli in unpolluted sites. Calcium, Cu, Mn, and Na showed an inverse correlation with the K content of the lichen. Calcium, Cu, and Sr showed an inverse correlation with the Fv/Fm ratio expressing the potential quantum yield of PSII. Calcium, Cr, Cu, Mg, Na, S, and Sr showed a positive correlation with the electrical conductivity corresponding with cell-membrane disintegration. The present study demonstrated a meaningful connection between enlarged concentrations of certain elements and physiological phenomena. The capability of the lichen to detect air pollution was found to be satisfactory. The dispersion of airborne heavy metals was found, however, to be local and limited to a few hundred meters from the source of pollution.