bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishing the impact of acid mine drainage through metal bioaccumulation and taxa richness of benthic insects in a tropical Asian stream (the Philippines)
Authors: David Carlos Primo C. 
Published: March 2005

Abstract
The Boac-Makulapnit River (The Philippines) is contaminated with heavy metals primarily due to acid mine drainage (AMD). Heavy-metal levels in river water, sediment, and algae suggest that Cu is the primary contaminant in this system. Copper concentrations decrease longitudinally, indicating a contamination gradient away from the mine. This is also reflected in the whole-body metal concentration of the caddisfly Hydropsyche, wherein higher Cu levels are observed in upstream stations (677–980 μg/g in 2001). In 2002, AMD formation was observed in a midstream station resulting from the oxidation of mine tailings in floodplains deposited during a 1996 tailings spill event. This consequently increased heavy-metal concentrations locally in environmental media and is likewise perceived to have caused the absence of aquatic insects in the midstream reach. Copper concentrations also increased in Hydropsyche found downstream of the new AMD site during this year. Furthermore, even the lower Cu concentrations in Hydropsyche observed in downstream stations are still at least six times higher than the established regional baseline value (29.9 μg/g), which is calculated from samples from clean tributary streams. These tributary streams also showed higher taxa richness for aquatic insect community in riffle zones. Both biomonitoring tools suggest that the whole length of the river is severely impacted. Rehabilitation projects will be underway next year; therefore, such monitoring programs will truly be beneficial when gauging river habitat recovery.
The effects of metals and food availability on the behavior of Caenorhabditis elegans
Authors: Boyd Windy A. , Cole Russell D. , Anderson Gary L. , Williams Phillip L. 
Published: March 2005

Abstract
Caenorhabditis elegans, a nonparasitic soil nematode, was used to assess the combined effects of metal exposures and food availability on behavior. Movement was monitored using a computer tracking system after exposures to Cu, Pb, or Cd while feeding was measured as a change in optical density (△OD) of bacteria suspensions over the exposure period. After 24-h exposures at high and low bacteria concentrations, movement was decreased in a concentration-dependent fashion by Pb and Cd but feeding reductions were not directly proportional to exposure concentrations. Copper exposure induced concentration-dependent declines in feeding and movement regardless of bacteria concentration. The impact of 24-h metal exposures was apparently reduced by increasing food availability. Therefore, exposures were shortened to 4 h in an attempt to minimize starvation effects on movement. Although nematodes were immobilized following 24 h of food depravation, worms deprived of food during the 4-h exposure continued to feed and move after exposure. A bead-ingestion assay after 4-h exposures was also used as an additional means of assessing the effects of metals on feeding behavior. Ingestion was significantly reduced by all concentrations of metals tested, indicating its sensitivity as a sublethal assay. Feeding (△OD) during exposures exhibited similar trends as ingestion but was slightly less sensitive, while movement was the least sensitive assay of 4-h metal exposures to C. elegans. Assessment of multiple sublethal endpoints allowed for the determination of the separate and interactive effects of metals and food availability on C. elegans behavior.
Constituents within pulp mill effluent deplete retinoid stores in white sucker and bind to rainbow trout retinoic acid receptors and retinoid × receptors
Authors: Alsop Derek , Hewitt Mark , Kohli Mohan , Brown Scott , Van Der Kraak Glen 
Published: March 2005

Abstract
Wild female and male white sucker (Catostomus commersoni) inhabiting an area receiving pulp mill effluent had reduced hepatic levels of retinol, didehydroretinol, retinyl esters, and didehydroretinyl esters, while vitamin E levels were unaffected. This disruption of the retinoid system led us to test methanol and dichloromethane extracts from the effluent of 11 pulp mills from across Canada for their ability to bind to rainbow trout (Oncorhynchus mykiss) retinoic acid receptors (RARs) from the gill and retinoid × receptors (RXRs) from the liver. Concentrated extracts of the final effluent from 6 of the 11 pulp mills were able to displace greater than 25% of the receptor-bound [3H]all-trans retinoic acid (RA) or [3H]9-cis RA from trout RARs and RXRs, respectively. The ability of the extracts to displace retinoic acid did not appear to be linked to the pulping or treatment processes. Moreover, extracts with the greatest activity came from thermomechanical mills, suggesting the compounds may originate from the wood furnish. In addition, extracts prepared from wood furnish (wood chips: white spruce [50%], lodgepole pine [47%], and balsam fir [3%]) from one mill were able to displace [3H]RA from the RARs and RXRs. The 4-hydroxy RA, a metabolite of RA that has been shown to be generated in greater quantities in fish exposed to P450-inducing xenobiotics, was able to displace [3H]all-trans RA from trout RARs as effectively as unlabeled all-trans RA. These results suggest that pulp mill effluent may impact the retinoid system of fish at multiple sites, either by decreasing hepatic retinoid stores or through contributing additional ligands (from the wood furnish) that can bind to RA receptors.
Toxicity of ambient atmospheric particulate matter from the lake Michigan (USA) airshed to aquatic organisms
Authors: Sheesley Rebecca J. , Schauer James J. , Hemming Jocelyn D. , Barman Miel A. , Geis Steven W. , Tortorelli James J. 
Published: March 2005

Abstract
Short-term chronic and acute aquatic bioassays are valuable tools in screening a variety of environmental samples. However, only a limited number of studies have used these methods for testing the toxicity of atmospheric particulate matter samples. Previous studies have shown that compounds known to have adverse biological effects, such as polycyclic aromatic hydrocarbons, are deposited in significant quantities into Lake Michigan (USA); however, these compounds comprise a small portion of the total particulate matter deposition. In the present study, a method is described for using Ceriodaphnia dubia, Selenastrum capricornutum (green algae), and MitoScan™ bioassays to compare the toxicities of reconstituted hard freshwater and methylene chloride extracts of atmospheric particulate matter collected at three locations around the southern shore of Lake Michigan in August 2000. The locations include an urban/industrial site in Milwaukee (WI, USA), an urban-impacted/industrial site in Porter (IN, USA), and a rural site in Bridgman (MI, USA). The bulk chemistry, including organic and elemental carbon, sulfate, nitrate, ammonium, and chloride, shows regional similarities over the sampling event, but the toxicities vary spatially by site, by extraction solvent, and by bioassay. Thus, the bioassays are sufficiently sensitive to show differences in toxicity among the atmospheric particulate matter extracts and have significantly different responses to the samples to enable an initial comparison of toxicity from the different sites.
Methylmercury production in high arctic wetlands
Authors: Loseto Lisa L. , Siciliano Steven D. , Lean David R. S. 
Published: March 2005

Abstract
Mercury is present at elevated levels in the top predators living in High Arctic ecosystems. Because only methylmercury (MeHg) bioaccumulates in food chains, the sources need to be identified. In temperate environments, wetlands are considered to be the principal sources of MeHg, with sulfate-reducing bacteria (SRB) thought to be responsible. The present study investigated whether High Arctic wetlands produced MeHg and whether SRB were involved in MeHg formation. Frozen soil was collected from 18 High Arctic wetlands before ground thaw, and when analyzed for MeHg, values were low, averaging 0.065 ng/g. When soils were incubated for 30 and 60 d at typical summer Arctic soil temperatures (4°C and 8°C), MeHg increased up to 100-fold. These laboratory observations were consistent with field measurements of wetland surface water, where MeHg concentrations increased from near detection limits (0.02 ng/L) at the inflow to an average of 1.21 ng/L at the outflow. Both laboratory and field data showed MeHg production in High Arctic wetlands. The prevalence of SRB in soil was low, however, and DNA analysis of the dissimilatory sulfate-reductase gene specific to SRB was positive at only one site. The present study showed that wetlands in the High Arctic can produce MeHg but that SRB may not the dominant mercury methylators.
Surveys of plasma vitellogenin and intersex in male flounder (Platichthys flesus) as measures of endocrine disruption by estrogenic contamination in United Kingdom estuaries: Temporal trends, 1996 to 2001
Authors: Kirby Mark F. , Allen Yvonne T. , Dyer Robert A. , Feist Steve W. , Katsiadaki Ioanna , Matthiessen Peter , Scott Alex P. , Smith Andrew , Stentiford Grant D. , Thain John E. , Thomas Kevin V. , Tolhurst Laura , Waldock Michael J. 
Published: March 2005

Abstract
Plasma vitellogenin (VTG) concentrations and the presence of the ovo-testis (intersex) condition have been recorded in male flounder (Platichthys flesus) captured from several United Kingdom (UK) estuaries since 1996 as part of the endocrine disruption in the Marine Environment (EDMAR) project and earlier programs. It has been confirmed that plasma VTG concentrations in male flounder have remained elevated in several UK estuaries (e.g., Tees, Mersey, and Tyne) throughout the period covered by this study. However, the time-series data indicate that plasma VTG, a measure of environmental estrogen contamination, has decreased in fish captured from several estuaries, especially those of the Tyne and Mersey. Shorter time-series data sets from the Forth and Clyde estuaries also suggest a decrease in estrogen contamination at these sites. Trends associated with specific point sources of estrogenic contamination show site-specific patterns. For instance, plasma VTG levels in male flounder captured near the Howdon sewage treatment outfall (Tyne) have shown a steady decline to near baseline levels in 2001, while the plasma of male fish captured at a site adjacent to the Dabholm Gut discharge in the Tees estuary have shown little evidence of a sustained decline. The occurrence of the intersex condition was detected at a low but consistent prevalence through the study period, with the majority of cases recorded in fish captured from the Tyne and Mersey estuaries. The data set does not allow conclusions to be drawn about any temporal trends associated with this condition. The significance of the findings and possible mitigating influences are discussed in terms of the impacts on wild fish and the role of effluent treatment in reducing these.
Organochlorine contaminants in sea turtles: Correlations between whole blood and fat
Authors: Keller Jennifer M. , Kucklick John R. , Harms Craig A. , McClellan-Green Patricia D. 
Published: March 2005

Abstract
Monitoring toxic organochlorine(OC)compounds is an important aspect in wildlife studies, especially in protected species such as sea turtles. The goal of this study was to determine whether blood OC concentrations can predict those in adipose tissue of sea turtles. Blood offers many benefits for monitoring OCs. It can be collected nondestructively from live turtles and can be sampled repeatedly for continuous monitoring. Organochlorine concentrations in blood may better represent the exposure levels of target tissues, but blood concentrations may fluctuate more than those in fatty tissues following recent dietary exposure or lipid mobilization. Paired fat and blood samples were collected from 44 live, juvenile loggerhead sea turtles and 10 juvenile Kemp's ridley sea turtle carcasses. Organochlorines were analyzed using gas chromatography with electron capture detection and mass spectrometry. Lipid-normalized OC concentrations measured in the blood significantly correlated to levels found in the fat samples of both species. This result suggests that sea turtle blood is a suitable alternative to fatty tissues for measuring OCs because blood concentrations reasonably represent those observed in the paired fat samples. However, blood OC concentrations calculated on a wet-mass basis were significantly and inversely correlated to lipid content in the fat samples. Therefore, caution should be used when monitoring spatial or temporal trends, as OC levels may increase in the blood following mobilization of fat stores, such as during long migrations, breeding, or disease events.
Dynamics of estrogen biomarker responses in rainbow trout exposed to 17β-estradiol and 17α-ethinylestradiol
Authors: Thomas-Jones Emma , Thorpe Karen , Harrison Nicola , Thomas Gethin , Morris Ceri , Hutchinson Thomas , Woodhead Stuart , Tyler Charles 
Published: March 2005

Abstract
We have investigated the response dynamics of the estrogen-dependent genes vitellogenin (VTG) and the vitelline envelope proteins (VEPs) as well as circulating VTG in immature female rainbow trout (Oncorhynchus mykiss) exposed to 17β-estradiol (E2) and 17α-efhinylestradiol (EE2) for periods of 7 and 14 d. Gene responses were quantified by measurement of messenger RNA (mRNA) in liver extracts using a chemiluminescent hybridization protection assay. Circulating VTG was measured by a homologous enzyme-linked immunosorbent assay. Exposure to both E2 and EE2 induced concentration-dependent increases in all biomarkers. The data presented indicate that VEP genes may be more sensitive to estrogens than the VTG gene. The biomarker lowest-observed-effect concentrations (biomarkerLOEC) in the 14-d study with E2 were 14 ng/L (VTG protein, VTG mRNA, VEPβ, and VEPγ) or 4.8 ng/L (VEPα). The EE2 was 5- to 66-fold more potent depending on the biomarker studied. In the 7-d study, all biomarkers were elevated after 48-h exposure to E2, with biomarkerLOECs of 30 ng/L (VTG protein, VTG mRNA, and VEPγ) or 9.7 ng/L (VEPα and VEPβ). Vitellogenin mRNA was induced up to 1,000-fold above baseline, and this translated into an increase of approximately 50,000-fold in circulating VTG. In conclusion, all biomarkers responded to estrogen exposure at environmentally relevant concentrations.
Investigations on the fate of sulfadiazine in manured soil: Laboratory experiments and test plot studies
Authors: Kreuzig Robert , Höltge Sibylla 
Published: March 2005

Abstract
The fate of 14C-labeled sulfadiazine (SDZ) in manured soil has been investigated in laboratory test systems. In the first approach, stability of 14C-SDZ in liquid bovine manure has been tested. Only 1% of the initially applied radiotracer was mineralized to 14C-carbon dioxide and 82% were transferred to nonextractable residues within a 102-d incubation period. Test slurries with defined aged residues were prepared and, supplementary to standard solutions, applied to silty-clay soil samples. These tests showed the high affinity of 14C-SDZ residues to the soil matrix. In the second approach, basic data on microbial, chemical, and photoinduced degradability in soil were gathered. The data indicated the formation of nonextractable residues as the predominant process in soil, which was accelerated by the test slurry application. In the third approach, laboratory lysimeter tests were conducted to investigate leaching and degradation as simultaneously occurring processes. The 14C-SDZ residues (64%) mainly were retained in the surface layer as nonextractable residues. Although a high mobility in soil was revealed by a soil/water distribution coefficient of 2 L kg−1, percolate contamination amounted to only 3% of the initially applied 14C-SDZ. The tendencies of leaching and degradability in soil also were observed in test plot studies under field conditions.
Pour-on formulation of eprinomectin for cattle: Fecal elimination profile and effects on the development of the dung-inhabiting Diptera Neomyia cornicina (L.) (Muscidae)
Authors: Lumaret Jean-Pierre , Errouissi Faiek , Galtier Pierre , Alvinerie Michel 
Published: March 2005

Abstract
The plasma and fecal concentrations ofeprinomectin weredetermined in cattlefollowing topical administrationat a dose rate of 0.5 mg kg−1. The maximum plasma concentrations of 12.24 ng ml−1 occurred 2 d after administration, and eprinomectin remained detectable in plasma 29 d after administration (0.10 ng ml−1). The maximum dung concentration of 350 ng g−1 was observed 3 d after administration and thereafter for at least 29 d (4 ng g−1). The amount of drug recovered in dung during this period was 20.50% ± 4.31% of the total administered dose. The effects of eprinomectin against the nontarget dung-feeding Diptera Neomyia cornicina was assessed under laboratory conditions. Feces voided by cattle treated with eprinomectin were associated with high larval mortality during the first 12 d after treatment, with null emergence until day 7. The no-observed-effect concentration for N. cornicina was estimated to be close to 7 ± 5 ng g−1.
Assimilation and bioconcentration of Ag and Cd by the marine black bream after waterborne and dietary metal exposure
Authors: Long Aimin , Wang Wen-Xiong 
Published: March 2005

Abstract
We determined the aqueous uptake and dietary assimilation of Cd and Ag by the marine black bream Acanthopagrus schlegeli following one to four weeks' exposure (or conditioning) to waterborne or dietary Cd or Ag at different concentrations. The concentrations of metals and metallothioneins (MT) in different tissues also were determined. The viscera contained the highest Ag, Cd, and MT concentrations after metal exposure. After exposure to waterborne metals, the metal and MT concentrations in the gills were higher than those in the remaining tissues (mainly muscles and bones), but this pattern was reversed following exposure to dietary metals. The assimilation efficiencies (AEs) of Cd and Ag ranged from 6 to 24% and 15 to 30%, respectively. The rate constant of uptake from the dissolved phase (ku) of Cd and Ag ranged from 2.2 to 7.5 and 8.0 to 31.7 L kg−1 d−1, respectively. In all the exposure experiments, the ku and AE increased with induced MT concentration and tissue metal concentration. Increasing metal accumulation may have been due to the increased available binding sites following the induction of MT in the fish. Furthermore, the MT induced by either Cd or Ag was not specific, but was able to bind with both metals and enhance bioaccumulation. Exposure to dissolved and dietary metals may increase metal accumulation, which potentially may lead to metal toxicity, although the fish may develop a tolerance to metals due to the apparent induction of MT.
Population genetic structure of a nonmigratory estuarine fish (Fundulus heteroclitus) across a strong gradient of polychlorinated biphenyl contamination
Authors: Roark Shaun A. , Nacci Diane , Coiro Laura , Champlin Denise , Guttman Sheldon I. 
Published: March 2005

Abstract
Populations of the estuarine fish Fundulus heteroclitus indigenous to contaminated sites exhibit heritable resistance to some of the toxic effects of early life-stage exposure to polychlorinated biphenyls (PCBs). This evolved tolerance provides evidence of strong selection by PCBs, and it suggests other potential genetic effects of these stressors on resident populations. Environmental contaminants have the potential to affect the genetic structure of populations and to reduce genetic diversity, but species life-history traits, particularly patterns of migration and dispersal, also influence the distribution of genetic variation among populations. Therefore, the present was conducted to determine whether genetic diversity or genetic structure is altered in populations of F. heteroclitus indigenous to 18 sites in Massachusetts (USA) and Rhode Island (USA), representing a steep gradient of sediment PCB contamination and culminating in a Superfund site at New Bedford Harbor (NBH; MA, USA). Allele frequencies at enzymatic loci were used to assess genetic structure and diversity. Selection experiments using a highly toxic PCB congener (3,3′,4,4′,5-pentachlorobiphenyl) were conducted to determine if genetic patterns at field sites could be associated with contaminant exposures. Although allele frequencies clearly reflected a pattern of isolation by distance, the results indicated neither significant loss of genetic diversity nor alteration of allele frequencies for populations of F. heteroclitus in NBH.
Population genetic structure and tolerance to dioxin-like compounds of a migratory marine fish (Menidia menidia) at polychlorinated biphenyl–contaminated and reference sites
Authors: Roark Shaun A. , Kelble Mary A. , Nacci Diane , Champlin Denise , Coiro Laura , Guttman Sheldon I. 
Published: March 2005

Abstract
The present study was conducted to evaluate evidence of genetic adaptation to local contaminants in populations of the migratory marine fish Menidia menidia residing seasonally in reference sites or an industrial harbor contaminated with dioxin-like compounds (DLCs). For this purpose, we compared DLC sensitivity and genetic patterns of populations sampled from sites both inside and outside New Bedford Harbor (NBH; MA, USA), a U.S. Environmental Protection Agency Superfund site with extreme polychlorinated biphenyl (PCB) contamination. Offspring of M. menidia collected from NBH were significantly less sensitive regarding embryonic exposure to the dioxin-like PCB congener 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) than offspring of M. menidia from a reference site. Analysis of 10 polymorphic enzymatic loci indicated little genetic differentiation among populations in the study area. However, genotype frequencies of juveniles from both NBH and an adjacent site in Massachusetts exhibited significant deviations from Hardy–Weinberg equilibrium expectations at one locus, phosphoglucomutase (PGM*). Genetic analysis of survivors of embryonic laboratory exposure to PCB 126 indicated that genotypes atPGM* were related to survivorship. Although a relationship was identified between DLC tolerance and PGM* genotype, regional mixing of M. menidia populations during migration and absence of multigeneration exposure at contaminated sites may limit localized adaptation.
Tumor prevalence and biomarkers of exposure and response in brown bullhead (Ameiurus nebulosus) from the Anacostia River, Washington, DC and Tuckahoe River, Maryland, USA
Authors: Pinkney Alfred E. , Harshbarger John C. , May Eric B. , Reichert William L. 
Published: March 2005

Abstract
We valuated liver and skin tumor prevalence and biomarkers of exposure and response in brown bullhead (Ameiurus nebulosus) from three locations in the Anacostia River (Washington, DC, USA), a Chesapeake Bay region of concern. The Tuckahoe River (Maryland, USA) served as a reference. Each river was sampled in fall 2000 and spring 2001. In the Anacostia, prevalence of liver tumors was 50 to 68%, and prevalence of skin tumors was 13 to 23% in large (≥260 mm, age ≥3 years) bullheads. Liver and skin tumor prevalence was 10 to 17% and 0%, respectively, in small (150–225 mm, age 1–2 years) bullheads. Tuckahoe bullhead liver tumor prevalence was 0 to 3% (large) and 0% (small); none had skin tumors. Biliary polynuclear aromatic hydrocarbon (PAH)-like fluorescent metabolites and liver DNA adduct concentrations were elevated in large and small Anacostia bullheads. Mean adduct concentrations were 16 to 28 times higher than those in Tuckahoe fish. Chromatograms revealed a diagonal radioactive zone, indicating polycyclic aromatic compound (PAC)-DNA adducts. The biomarker data and the 10 to 17% liver tumor prevalence at ages 1 to 2 suggest that these year classes are likely to have a high prevalence as they reach age 3 and older. This study provides the strongest evidence to date of the role of PAHs in tumor development in Anacostia bullheads.