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Sample records for environmentally relevant levels

  1. Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development.

    PubMed

    Gillespie, Colin; Stabler, Daniel; Tallentire, Eva; Goumenaki, Eleni; Barnes, Jeremy

    2015-11-01

    A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions - pollen originating from plants raised in charcoal-Purafil(®) filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O3. The O3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O3 × CFA and CFA × O3 crossed plants. This suggests O3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol(-1) O3 (10 h d(-1)) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit - a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O3, and potentially other gaseous pollutants, on reproductive biology during 'risk assessment' exercises.

  2. Environmentally relevant microorganisms.

    PubMed

    Watanabe, K; Baker, P W

    2000-01-01

    The development of molecular microbial ecology in the 1990s has allowed scientists to realize that microbial populations in the natural environment are much more diverse than microorganisms so far isolated in the laboratory. This finding has exerted a significant impact on environmental biotechnology, since knowledge in this field has been largely dependent on studies with pollutant-degrading bacteria isolated by conventional culture methods. Researchers have thus started to use molecular ecological methods to analyze microbial populations relevant to pollutant degradation in the environment (called environmentally relevant microorganisms, ERMs), although further effort is needed to gain practical benefits from these studies. This review highlights the utility and limitations of molecular ecological methods for understanding and advancing environmental biotechnology processes. The importance of the combined use of molecular ecological and physiological methods for identifying ERMs is stressed.

  3. A metabolomic study of fipronil for the anxiety-like behavior in zebrafish larvae at environmentally relevant levels.

    PubMed

    Wang, Cui; Qian, Yi; Zhang, Xiaofeng; Chen, Fang; Zhang, Quan; Li, Zhuoyu; Zhao, Meirong

    2016-04-01

    Field residue of fipronil can interfere with the physiological characters of the domesticated fish; thus, lethal dose test and the general biomarker cannot delineate the low-level situation. Manipulating by video track, we observed an anxiety-like behavior including high speed and abnormal photoperiod accommodation after exposure to fipronil at environmental typical dose in zebrafish larvae. Examining the unbiased metabolomic profiles, we found perturbation in several metabolic pathways, including the increased contents of fatty acids and glycerol and the decreased levels of the glycine, serine, and branched amino acid. We presumed that observed enhanced fatty acid utility was in response to increase energy demands caused by anxiety like behavior. Additionally, the body burden of neurotransmitter such as glycine and L-glutamate may concurrently stimulate the swimming behavior. The insight of this study showed that integral perturbation such as metabolism helps us to further understand the risk to aquatic fish at the environmentally relevant levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Environmentally relevant level of aflatoxin B1 elicits toxic pro-inflammatory response in murine CNS-derived cells.

    PubMed

    Mehrzad, Jalil; Malvandi, Amir Mohammad; Alipour, Mohsen; Hosseinkhani, Saman

    2017-09-05

    Aflatoxin B1 (AFB1) is a well-known member of aflatoxins (AFs) that is considered among highly stable toxic contaminants of food, worldwide. The impact of AFB1 on neural cells and systems has poorly been understood. To assess the cellular effects of AFB1 on brain, we used murine pure primary astrocytes, sub ventricular zone-derived neural precursor cells (NPCs) and microglia cell line (BV2). Cells were exposed separately to environmentally relevant level (20ng/ml) of AFB1 for 1, 2, 3, 6, 12, 24 and 48h in culture. At each time points, total free radicals production measured by luminol-enhanced cellular chemiluminescence (CL) assay; cytokines production of IL-1β, IL-6, TNF-α and IL-10 were analyzed using Bioplex ELISA and a set of genes involved in the immediate response to danger such as TLR2, TLR4 and iNOS etc. were evaluated by multiplex qPCR. Upon AFB1 exposure production, of the total free radicals significantly increased only in microglial cells after 24h and slightly elevated in the other examined cells. AFB1 also induced secretion of pro-inflammatory cytokines (i.e. TNF-α and IL-6) on both microglial cells (more TNF-α) and astrocytes (more IL-6). mRNA expression of TLR2, TLR4, MyD88 and NF-κB were up-regulated with different timing and levels among cells. Immunotoxicologically, microglial cells, and astrocytes, but not NPCs, are capable of sensing a low level of AFB1. Thus, the pro-inflammatory effects of an environmentally relevant dose of AFB1 on CNS-derived cells in vitro could potentially explain the immune dysregulation in neurodegenerative disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Repository environmental parameters and models/methodologies relevant to assessing the performance of high-level waste packages in basalt, tuff, and salt

    SciTech Connect

    Claiborne, H.C.; Croff, A.G.; Griess, J.C.; Smith, F.J.

    1987-09-01

    This document provides specifications for models/methodologies that could be employed in determining postclosure repository environmental parameters relevant to the performance of high-level waste packages for the Basalt Waste Isolation Project (BWIP) at Richland, Washington, the tuff at Yucca Mountain by the Nevada Test Site, and the bedded salt in Deaf Smith County, Texas. Guidance is provided on the identify of the relevant repository environmental parameters; the models/methodologies employed to determine the parameters, and the input data base for the models/methodologies. Supporting studies included are an analysis of potential waste package failure modes leading to identification of the relevant repository environmental parameters, an evaluation of the credible range of the repository environmental parameters, and a summary of the review of existing models/methodologies currently employed in determining repository environmental parameters relevant to waste package performance. 327 refs., 26 figs., 19 tabs.

  6. Zebrafish exposure to environmentally relevant concentration of depleted uranium impairs progeny development at the molecular and histological levels

    PubMed Central

    Gombeau, Kewin; Murat El Houdigui, Sophia; Floriani, Magali; Camilleri, Virginie; Cavalie, Isabelle; Adam-Guillermin, Christelle

    2017-01-01

    parental exposure to an environmentally relevant concentration of DU could impair the progeny development with significant effects observed both at the molecular level and on the histological ultrastructure of organs. This study provides a comprehensive transcriptomic dataset useful for ecotoxicological studies on other fish species at the molecular level. It also provides a key DU responsive gene, egr1, which may be a candidate biomarker for monitoring aquatic pollution by heavy metals. PMID:28531178

  7. Cadmium toxicity investigated at the physiological and biophysical levels under environmentally relevant conditions using the aquatic model plant Ceratophyllum demersum.

    PubMed

    Andresen, Elisa; Kappel, Sophie; Stärk, Hans-Joachim; Riegger, Ulrike; Borovec, Jakub; Mattusch, Jürgen; Heinz, Andrea; Schmelzer, Christian E H; Matoušková, Šárka; Dickinson, Bryan; Küpper, Hendrik

    2016-06-01

    Cadmium (Cd) is an important environmental pollutant and is poisonous to most organisms. We aimed to unravel the mechanisms of Cd toxicity in the model water plant Ceratophyllum demersum exposed to low (nM) concentrations of Cd as are present in nature. Experiments were conducted under environmentally relevant conditions, including nature-like light and temperature cycles, and a low biomass to water ratio. We measured chlorophyll (Chl) fluorescence kinetics, oxygen exchange, the concentrations of reactive oxygen species and pigments, metal binding to proteins, and the accumulation of starch and metals. The inhibition threshold concentration for most parameters was 20 nM. Below this concentration, hardly any stress symptoms were observed. The first site of inhibition was photosynthetic light reactions (the maximal quantum yield of photosystem II (PSII) reaction centre measured as Fv /Fm , light-acclimated PSII activity ΦPSII , and total Chl). Trimers of the PSII light-harvesting complexes (LHCIIs) decreased more than LHC monomers and detection of Cd in the monomers suggested replacement of magnesium (Mg) by Cd in the Chl molecules. As a consequence of dysfunctional photosynthesis and energy dissipation, reactive oxygen species (superoxide and hydrogen peroxide) appeared. Cadmium had negative effects on macrophytes at much lower concentrations than reported previously, emphasizing the importance of studies applying environmentally relevant conditions. A chain of inhibition events could be established. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  8. AN APPROACH TO THE DEVELOPMENT OF MODELS TO QUANTITATIVELY ASSESS THE EFFECTS OF EXPOSURE TO ENVIRONMENTALLY RELEVANT LEVELS OF ENDOCRINE DISRUPTORS

    EPA Science Inventory

    An approach to the development of quantitative models to assess the effects of exposure to environmentally relevant levels of endocrine disruptors on homeostasis in adults.

    Ben-Jonathan N, Cooper RL, Foster P, Hughes CL, Hoyer PB, Klotz D, Kohn M, Lamb DJ, Stancel GM.
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  9. Determination of environmentally relevant aromatic amines in the ppt levels by cation selective exhaustive injection-sweeping-micellar electrokinetic chromatography.

    PubMed

    Quirino, J P; Iwai, Y; Otsuka, K; Terabe, S

    2000-08-01

    Environmentally important aromatic amines are determined by micellar electrokinetic chromatography (MEKC) with UV detection. Using a combination of field-enhanced sample injection in the capillary zone electrophoresis format (performed for a longer period than usual, e.g., 200 s at high voltages; cation selective exhaustive injection) and sweeping in the MEKC format, from 10(4)- to 10(5)-fold improvements in detector response are achieved for all positively chargeable test analytes. Preliminary results indicate that limits of detection for the positively chargeable aromatic amines are in the parts per trillion (ppt) levels.

  10. Perinatal Exposure to Environmentally Relevant Levels of Bisphenol A Decreases Fertility and Fecundity in CD-1 Mice

    PubMed Central

    Cabaton, Nicolas J.; Wadia, Perinaaz R.; Rubin, Beverly S.; Zalko, Daniel; Schaeberle, Cheryl M.; Askenase, Michael H.; Gadbois, Jennifer L.; Tharp, Andrew P.; Whitt, Gregory S.; Sonnenschein, Carlos; Soto, Ana M.

    2011-01-01

    Background Perinatal exposure to low-doses of bisphenol A (BPA) results in alterations in the ovary, uterus, and mammary glands and in a sexually dimorphic region of the brain known to be important for estrous cyclicity. Objectives We aimed to determine whether perinatal exposure to environmentally relevant doses of BPA alters reproductive capacity. Methods Female CD-1 mice that were exposed to BPA at 0, 25 ng, 250 ng, or 25 μg/kg body weight (BW)/day or diethylstilbestrol (DES) at 10 ng/kg BW/day (positive control) from gestational day 8 through day 16 of lactation were continuously housed with proven breeder males for 32 weeks starting at 2 months of age. At each delivery, pups born to these mating pairs were removed. The cumulative number of pups, number of deliveries, and litter size were recorded. The purity of the BPA used in this and our previous studies was assessed using HPLC, mass spectrometry, and nuclear magnetic resonance. Results The forced breeding experiment revealed a decrease in the cumulative number of pups, observed as a nonmonotonic dose–response effect, and a decline in fertility and fecundity over time in female mice exposed perinatally to BPA. The BPA was 97% pure, with no evidence of contamination by other phenolic compounds. Conclusions Perinatal exposure to BPA leads to a dose-dependent decline in the reproductive capacity of female mice. The effects on the cumulative number of pups are comparable to those previously reported in mice developmentally exposed to DES, a compound well known to impair reproduction in women. This association suggests the possibility that early BPA exposure may also affect reproductive capacity in women. PMID:21126938

  11. Effects of biopellets composed of microalgae and fungi on cadmium present at environmentally relevant levels in water.

    PubMed

    Bodin, Hristina; Asp, Håkan; Hultberg, Malin

    2017-05-04

    Removal of cadmium (Cd) present at low levels (1 µg L(-1)) in water was investigated using three different microorganism treatments: the microalga Chlorella vulgaris, the fungus Aspergillus niger, and for the first time biopellets composed of C. vulgaris and A. niger. After 5 days, all microorganism treatments resulted in significantly lower Cd concentrations compared with the control. Biopellets treatment resulted in significantly lower pH values than other microorganism treatments, indicating that the biopellets should be investigated further for their water treatment capacity, since pH is a factor affecting the fate of numerous pollutants in water. Use of biopellets as a method to simplify harvesting of microalgae from water is also suggested.

  12. COMPARING ENVIRONMENTALLY RELEVANT PCBS TO TCDD

    EPA Science Inventory

    COMPARING ENVIRONMENTALLY RELEVANT PCBS TO TCDD. D E Burgin1, J J Diliberto2 and L S Birnbaum3.1UNC, Chapel Hill, NC, USA; 2USEPA/ORD/NHEERL, ETD, RTP, NC, USA

    Environmental exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) always occur as part of a complex mixture. ...

  13. COMPARING ENVIRONMENTALLY RELEVANT PCBS TO TCDD

    EPA Science Inventory

    COMPARING ENVIRONMENTALLY RELEVANT PCBS TO TCDD. D E Burgin1, J J Diliberto2 and L S Birnbaum3.1UNC, Chapel Hill, NC, USA; 2USEPA/ORD/NHEERL, ETD, RTP, NC, USA

    Environmental exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) always occur as part of a complex mixture. ...

  14. Environmentally relevant levels of λ-cyhalothrin, fenvalerate, and permethrin cause developmental toxicity and disrupt endocrine system in zebrafish (Danio rerio) embryo.

    PubMed

    Zhang, Quan; Zhang, Yi; Du, Jie; Zhao, Meirong

    2017-10-01

    Synthetic pyrethroids (SPs) are one of the most widely used pesticides and frequently detected in the aquatic environment. Previous studies have shown that SPs posed high aquatic toxicity, but information on the developmental toxicity and endocrine disruption on zebrafish (Danio rerio) at environmentally relevant concentrations is limited. In this study, zebrafish embryos were employed to examine the adverse effects of λ-cyhalothrin (LCT), fenvalerate (FEN), and permethrin (PM) at 2.5, 10, 25, 125, 500 nM for 96 h. The results showed these 3 SPs caused dose-dependent mortality, malformation rate, and hatching rate. Thyroid hormone triiodothyronine (T3) levels were significantly decreased after exposure to LCT and FEN. Quantitative real-time PCR analysis was then performed on a series of nuclear receptors (NRs) genes involved in the hypothalamic-pituitary-gonadal (HPG), hypothalamic-pituitary-thyroid (HPT), hypothalamic-pituitary-adrenocortical (HPA) axes, and oxidative-stress-related system. Our results showed that LCT, FEN, and PM downregulated AR expression while upregulated ER1 expression, and caused alteration to ER2a and ER2b expression. As for the expression of TRα and TRβ, they were both decreased following exposure to the 3 SPs. LCT and PM downregulated the MR expression and FEN induced MR expression. In addition, the expression of GR was increased after treating with LCT, while it was suppressed after exposure to FEN and PM. The 3 SPs also caused various alterations to the expression of genes including AhRs, PPARα, and PXR. These findings suggest that these 3 SPs may cause developmental toxicity to zebrafish larvae by disrupting endocrine signaling at environmentally relevant concentrations. Copyright © 2017. Published by Elsevier Ltd.

  15. Quantification of (226)Ra at environmental relevant levels in natural waters by ICP-MS: Optimization, validation and limitations of an extraction and preconcentration approach.

    PubMed

    Lagacé, François; Foucher, Delphine; Surette, Céline; Clarisse, Olivier

    2017-05-15

    Radium (Ra) at environmental relevant levels in natural waters was determined by ICP-MS after an off-line pre-concentration procedure. The latter consisted of Ra selective elution from potential interfering elements (i.e. other alkaline earth cations: Ba(2+), Sr(2+), Ca(2+), Mg(2+)) on a series of two different ion exchange resins (AG50W-X8 and Sr-resin). The overall analytical method was optimized according to the instrumental performance, the volume of water sample loaded on resins, and the sample salinity. Longer acquisition time (up to 150 s) was required to ensure stable measurement of Ra by ICP-MS at ultra trace level (1.0pgL(-1)). For a synthetic groundwater spiked with Ra at 10.0pgL(-1), the analytical procedure demonstrated efficient separation of the analyte from its potential interfering elements and a complete recovery, independent of the sample volume tested from 10 up to 100mL. For synthetic seawater spiked at a level of 10.0pgL(-1) of Ra, the total load of salts on the two resins should not exceed 0.35g in order to ensure a complete separation and recovery of Ra. The method was validated on natural waters (i.e. groundwater, freshwater and seawater samples) spiked with Ra at different levels (0.0, 0.5, 1.0 and 5.0pgL(-1)). Absolute Ra detection limits were determined at 0.020pgL(-1) (0.73mBqL(-1)) and 0.12pgL(-1) (4.4mBqL(-1)) respectively for 60.0mL of freshwater sample and for 10.0mL of seawater. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Exposure of silver carp (Hypophthalmichthys molitrix) to environmentally relevant levels of cadmium: hematology, muscle physiology, and implications for stock enhancement in the Xiangjiang River (Hunan, China).

    PubMed

    Zhang, Ting; Zhang, Yu; Li, DeLiang; Xiao, TiaoYi; Li, Jie

    2013-01-01

    Cadmium is a non-essential metal with a wide distribution that has severe toxic effects on aquatic animals. Changes in hematology and muscle physiology were examined in silver carp (Hypophthalmichthys molitrix) exposed to environmentally relevant levels of cadmium (0.01 mg L(-1)) for 96 h. Cadmium exposure induced significant increases in the red blood cell count, and in the plasma concentrations of cortisol, glucose, and lactate. This suggests that the dose of cadmium was sufficient to cause stress, possibly associated with impaired gas exchange at the gills. There were no changes in hemoglobin concentration or plasma protein concentration. Significant decreases in muscle energy fuels (ATP and glycogen), and increases in muscle lactate persisted until the end of the exposure period, respectively. The changes in muscle lactate and protein in silver carp differed from those observed in response to exposure of fish to cadmium and heavy metals in other studies. The study highlights the importance of selecting unpolluted release sites with suitable water conditions for the survival of newly released individuals for stock enhancement of the Xiangjiang River.

  17. Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation.

    PubMed

    Birch, Heidi; Hammershøj, Rikke; Comber, Mike; Mayer, Philipp

    2017-10-01

    Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng-μg/L levels. Automated Headspace Solid Phase Microextraction coupled to GC-MS was applied directly to these test systems to determine substrate depletion relative to abiotic controls. Lag phases were generally less than 8 days. First order rate constants were within one order of magnitude for each hydrocarbon in four of the five waters but lower in water from a rural lake. The sequence of degradation between the 9 hydrocarbons showed similar patterns in the five waters indicating the potential for using selected hydrocarbons for benchmarking between biodegradation tests. Degradation half-times were shorter than or within one order of magnitude of BioHCwin predictions for 8 of 9 hydrocarbons. These results showed that location choice is important for biodegradation kinetics and can provide a relevant input to aquatic exposure and fate models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Environmental Factors Impacting Bone-Relevant Chemokines

    PubMed Central

    Smith, Justin T.; Schneider, Andrew D.; Katchko, Karina M.; Yun, Chawon; Hsu, Erin L.

    2017-01-01

    Chemokines play an important role in normal bone physiology and the pathophysiology of many bone diseases. The recent increased focus on the individual roles of this class of proteins in the context of bone has shown that members of the two major chemokine subfamilies—CC and CXC—support or promote the formation of new bone and the remodeling of existing bone in response to a myriad of stimuli. These chemotactic molecules are crucial in orchestrating appropriate cellular homing, osteoblastogenesis, and osteoclastogenesis during normal bone repair. Bone healing is a complex cascade of carefully regulated processes, including inflammation, progenitor cell recruitment, differentiation, and remodeling. The extensive role of chemokines in these processes and the known links between environmental contaminants and chemokine expression/activity leaves ample opportunity for disruption of bone healing by environmental factors. However, despite increased clinical awareness, the potential impact of many of these environmental factors on bone-related chemokines is still ill defined. A great deal of focus has been placed on environmental exposure to various endocrine disruptors (bisphenol A, phthalate esters, etc.), volatile organic compounds, dioxins, and heavy metals, though mainly in other tissues. Awareness of the impact of other less well-studied bone toxicants, such as fluoride, mold and fungal toxins, asbestos, and chlorine, is also reviewed. In many cases, the literature on these toxins in osteogenic models is lacking. However, research focused on their effects in other tissues and cell lines provides clues for where future resources could be best utilized. This review aims to serve as a current and exhaustive resource detailing the known links between several classes of high-interest environmental pollutants and their interaction with the chemokines relevant to bone healing. PMID:28261155

  19. Ligand Exchange Kinetics of Environmentally Relevant Metals

    SciTech Connect

    Panasci, Adele Frances

    2014-07-15

    The interactions of ground water with minerals and contaminants are of broad interest for geochemists but are not well understood. Experiments on the molecular scale can determine reaction parameters (i.e. rates of ligand exchange, activation entropy, activation entropy, and activation volume) that can be used in computations to gain insight into reactions that occur in natural groundwaters. Experiments to determine the rate of isotopic ligand exchange for three environmentally relevant metals, rhodium (Rh), iron (Fe), and neptunium (Np), are described. Many environmental transformations of metals (e.g. reduction) in soil occur at trivalent centers, Fe(III) in particular. Contaminant ions absorb to mineral surfaces via ligand exchange, and the reversal of this reaction can be dangerous, releasing contaminants into the environment. Ferric iron is difficult to study spectroscopically because most of its complexes are paramagnetic and are generally reactive toward ligand exchange; therefore, Rh(III), which is diamagnetic and less reactive, was used to study substitution reactions that are analogous to those that occur on mineral oxide surfaces. Studies on both Np(V) and Np(VI) are important in their own right, as 237Np is a radioactive transuranic element with a half-life of 2 million years.

  20. Low environmentally relevant levels of bioactive xenobiotics and associated degradation products cause cryptic perturbations of metabolism and molecular stress responses in Arabidopsis thaliana.

    PubMed

    Serra, Anne-Antonella; Nuttens, Andréïna; Larvor, Vanessa; Renault, David; Couée, Ivan; Sulmon, Cécile; Gouesbet, Gwenola

    2013-07-01

    Anthropic changes and chemical pollution confront wild plant communities with xenobiotic combinations of bioactive molecules, degradation products, and adjuvants that constitute chemical challenges potentially affecting plant growth and fitness. Such complex challenges involving residual contamination and mixtures of pollutants are difficult to assess. The model plant Arabidopsis thaliana was confronted by combinations consisting of the herbicide glyphosate, the fungicide tebuconazole, the glyphosate degradation product aminomethylphosphonic acid (AMPA), and the atrazine degradation product hydroxyatrazine, which had been detected and quantified in soils of field margins in an agriculturally intensive region. Integrative analysis of physiological, metabolic, and gene expression responses was carried out in dose-response experiments and in comparative experiments of varying pesticide combinations. Field margin contamination levels had significant effects on plant growth and metabolism despite low levels of individual components and the presence of pesticide degradation products. Biochemical and molecular analysis demonstrated that these less toxic degradation products, AMPA and hydroxyatrazine, by themselves elicited significant plant responses, thus indicating underlying mechanisms of perception and transduction into metabolic and gene expression changes. These mechanisms may explain observed interactions, whether positive or negative, between the effects of pesticide products (AMPA and hydroxyatrazine) and the effects of bioactive xenobiotics (glyphosate and tebuconazole). Finally, the metabolic and molecular perturbations induced by low levels of xenobiotics and associated degradation products were shown to affect processes (carbon balance, hormone balance, antioxidant defence, and detoxification) that are likely to determine environmental stress sensitivity.

  1. Effects of Environmentally Relevant Levels of Perfluorooctane Sulfonate on Clinical Parameters and Immunological Functions in B6C3F1 Mice

    PubMed Central

    Fair, Patricia A.; Driscoll, Erin; Mollenhauer, Meagan A. M.; Bradshaw, Sarah G.; Yun, Se Hun; Kannan, Kurunthachalam; Bossart, Gregory D.; Keil, Deborah E.; Peden-Adams, Margie M.

    2012-01-01

    In the first part of a series of studies to account for perfluoroocatane sulfonate (PFOS)-induced sheep red blood cell (SRBC)-specific IgM antibody suppression in mice, a survey of clinical and immunotoxicological endpoints were examined. Adult female B6C3F1 mice were exposed orally for 28 days to a total administered dose of 0, 0.1, 0.5, 1, or 5 mg PFOS/kg. Uterus wet weight was significantly decreased compared to control at the 5 mg/kg dose. No indication of wasting syndrome, malnutrition, alteration of thyroid homeostasis, or signs of overt toxicity were observed. Numbers of splenic CD19+/CD21−, CD19+/CD21+, B220+/CD40+, CD4+/CD154−, CD4+/CD154+, and MHC-II+ cells were not altered. Additionally, ex vivo IL-4, IL-5, and IL-6 production by in vitro anti-CD3- or phorbol myristate acetate-stimulated CD4+ T-cells were not affected. Ex vivo IL-6 production by B-cells was significantly increased by in vitro stimulation with either anti-CD40 or lipopolysaccharide. Increased IL-6 production by B-cells was the most sensitive endpoint assessed resulting in alterations at the lowest dose tested (0.1 mg/kg TAD) following anti-CD40 stimulation. Further studies are required to characterize effects on inflammatory markers such as IL-6 at environmentally relevant concentrations of PFOS and to determine the key events associated with PFOS-induced IgM suppression to address potential human health risks. PMID:21261439

  2. Developing an Environmental Currency Relevant to People

    EPA Science Inventory

    EPA (and others worldwide) wanted to more fully include environmental attributes in decision making but there was no systematic approach that defined and organized the environment to identify and potentially quantify those environmental attributes that humans required, valued, or...

  3. Developing an Environmental Currency Relevant to People

    EPA Science Inventory

    EPA (and others worldwide) wanted to more fully include environmental attributes in decision making but there was no systematic approach that defined and organized the environment to identify and potentially quantify those environmental attributes that humans required, valued, or...

  4. Environmental Service Learning: Relevant, Rewarding, and Responsible

    ERIC Educational Resources Information Center

    Leege, Lissa; Cawthorn, Michelle

    2008-01-01

    At Georgia Southern University (GSU), a regional university of 17,000 students, environmental science is a required introductory course for all students. Consequently, environmental-biology class sizes are large, often approaching 1,000 students each semester in multiple sections of up to 250 students. To improve students' learning and sense of…

  5. Health, growth and reproductive success of mice exposed to environmentally relevant levels of Ra-226 via drinking water over multiple generations.

    PubMed

    Walsh, Stephanie; Satkunam, Meloja; Su, Ben; Festarini, Amy; Bugden, Michelle; Peery, Harry; Mothersill, Carmel; Stuart, Marilyne

    2015-07-01

    To assess health, growth and reproductive success of mammals exposed for multiple generations to levels of radium-226 known to occur in environments surrounding uranium mines and mills in Canada. The study consisted of a control group and four treatment groups each containing 40 mice (20 males and 20 females) of the CBA/CaJ strain that were continuously exposed to a range of radium-226 levels via drinking water. Breeding was at 8-10 weeks of age and the study was concluded after three breeding cycles. When compared to control mice, constant consumption of drinking water containing 0.012, 0.076, 0.78 and 8.0 Bq/l of radium-226 over four generations of mice did not demonstrably affect physical condition, weight, pregnancy rate, number of pups per litter, sex ratio and bodyweight gain of pups. Between generations, the observed differences in pregnancy rates that were noted in all groups, including controls, seemed to directly correlate with the weight and age of the females at breeding. Based on the endpoints measured on four generations of mice, there is no indication that the consumption of radium-226 via drinking water (at activity concentrations up to 8.0 Bq/l) affects health, growth and reproductive fitness.

  6. HUMAN BIOMONITORING TO LINK ENVIRONMENTAL EXPOSURE TO BIOLOGICALLY RELEVANT DOSE

    EPA Science Inventory

    The abstract and presentation on Human Biomonitoring to Link Environmental Exposure to Biologically Relevant Dose describes the use of biomarkers of exposure, biomarkers of current health state, and biomarker measurements. The abstract and presentation focuses on how biomarkers ...

  7. A Critical Urban Environmental Pedagogy: Relevant Urban Environmental Education for and by Youth

    ERIC Educational Resources Information Center

    Bellino, Marissa E.; Adams, Jennifer D.

    2017-01-01

    This article reimagines environmental education (EE), moving away from traditional models of EE rooted in nature studies and pro-environmental behaviors. Using the pedagogical praxis and intent of critical pedagogy and participatory methodologies, this critical urban environmental pedagogy (CUEP) investigates relevant socioenvironmental issues…

  8. Mobility of capped silver nanoparticles under environmentally relevant conditions.

    PubMed

    Thio, Beng Joo Reginald; Montes, Milka O; Mahmoud, Mahmoud A; Lee, Dong-Woog; Zhou, Dongxu; Keller, Arturo A

    2012-07-03

    The mobility and deposition of capped silver (Ag) nanoparticles (NPs) on silica surfaces were characterized over a wide range of pH and ionic strength (IS) conditions, including seawater and freshwater. Two common organic capping agents (citrate and PVP) were evaluated. Both the capped Ag NPs and the silica surfaces were negatively charged under these environmentally relevant conditions, resulting in net repulsive electrostatics under most conditions. The steric repulsion introduced by the capping agents significantly reduced aggregation and deposition. In addition, the presence of natural organic matter in solution further decreased the deposition of either Ag NP on silica. Ag NPs were found to be highly mobile under these environmentally relevant conditions, with little or no deposition.

  9. Environmentally relevant concentrations of microplastic particles influence larval fish ecology.

    PubMed

    Lönnstedt, Oona M; Eklöv, Peter

    2016-06-03

    The widespread occurrence and accumulation of plastic waste in the environment have become a growing global concern over the past decade. Although some marine organisms have been shown to ingest plastic, few studies have investigated the ecological effects of plastic waste on animals. Here we show that exposure to environmentally relevant concentrations of microplastic polystyrene particles (90 micrometers) inhibits hatching, decreases growth rates, and alters feeding preferences and innate behaviors of European perch (Perca fluviatilis) larvae. Furthermore, individuals exposed to microplastics do not respond to olfactory threat cues, which greatly increases predator-induced mortality rates. Our results demonstrate that microplastic particles operate both chemically and physically on larval fish performance and development.

  10. Towards policy relevant environmental modeling: contextual validity and pragmatic models

    USGS Publications Warehouse

    Miles, Scott B.

    2000-01-01

    "What makes for a good model?" In various forms, this question is a question that, undoubtedly, many people, businesses, and institutions ponder with regards to their particular domain of modeling. One particular domain that is wrestling with this question is the multidisciplinary field of environmental modeling. Examples of environmental models range from models of contaminated ground water flow to the economic impact of natural disasters, such as earthquakes. One of the distinguishing claims of the field is the relevancy of environmental modeling to policy and environment-related decision-making in general. A pervasive view by both scientists and decision-makers is that a "good" model is one that is an accurate predictor. Thus, determining whether a model is "accurate" or "correct" is done by comparing model output to empirical observations. The expected outcome of this process, usually referred to as "validation" or "ground truthing," is a stamp on the model in question of "valid" or "not valid" that serves to indicate whether or not the model will be reliable before it is put into service in a decision-making context. In this paper, I begin by elaborating on the prevailing view of model validation and why this view must change. Drawing from concepts coming out of the studies of science and technology, I go on to propose a contextual view of validity that can overcome the problems associated with "ground truthing" models as an indicator of model goodness. The problem of how we talk about and determine model validity has much to do about how we perceive the utility of environmental models. In the remainder of the paper, I argue that we should adopt ideas of pragmatism in judging what makes for a good model and, in turn, developing good models. From such a perspective of model goodness, good environmental models should facilitate communication, convey—not bury or "eliminate"—uncertainties, and, thus, afford the active building of consensus decisions, instead

  11. Environmentally Relevant Inoculum Concentrations Improve the Reliability of Persistent Assessments in Biodegradation Screening Tests.

    PubMed

    Martin, Timothy J; Snape, Jason R; Bartram, Abigail; Robson, Aidan; Acharya, Kishor; Davenport, Russell J

    2017-03-07

    Standard OECD biodegradation screening tests (BSTs) have not evolved at the same rate as regulatory concerns, which now place an increased emphasis on environmental persistence. Consequently, many chemicals are falsely assigned as being potentially persistent based on results from BSTs. The present study increased test duration and increased inoculum concentrations to more environmentally relevant levels to assess their impact on biodegradation outcome and intratest replicate variability for chemicals with known environmental persistence. Chemicals were assigned to potential persistence categories based on existing degradation data. These more environmentally relevant BSTs (erBSTs) improved the reliability of persistence assignment by reducing the high variability associated with these tests and the occurrence of failures at low inoculum concentrations due to the exclusion of specific degraders. Environmental fate was determined using a reference set of (14)C-labeled compounds with a range of potential environmental persistences, and full mass balance data were collated. The erBST correctly assigned five reference chemicals of known biodegradabilities to their appropriate persistence category in contrast to a standard OECD Ready Biodegradation Test (RBTs, P < 0.05). The erBST was significantly more reproducible than an OECD RBT (ANOVA, P < 0.05), with more consistent rates and extent of biodegradation observed in the erBST.

  12. The effects of space relevant environmental factors on halophilic Archaea

    NASA Astrophysics Data System (ADS)

    Leuko, Stefan; Moeller, Ralf; Rettberg, Petra

    Within the last 50 years, space technology has provided tools for transporting terrestrial (microbial) life beyond Earth's protective shield in order to study its responses to selected conditions of space. Microorganisms are ubiquitous and can be found in almost every environment on Earth. They thrive and survive in a broad spectrum of environments and are true masters in adapting to rapidly changing external conditions. Although microorganisms cannot actively grow under the harsh conditions of outer space or other known planets, some microorganisms might be able to survive for a time in space or other planets as dormant, inactive spores or in similar desiccation-resistant resting states, e.g., enclosed in halite crystals or biofilms. Halite crystals are the realm of halophilic Archaea as they have adapted to life at extreme salt concentrations. They can stay entrapped in such crystals for millions of years without losing viability and therefore the family Halobacteriaceae belongs to the group of microorganisms which may survive space travel or may even be found on other planets. Several members of this family have been utilized in space relevant experiments where they were exposed to detrimental environmental conditions such as UV-C radiation, vacuum, temperature cycles (+60(°) C and -25(°) C) and heavy iron bombardment (150 MeV He, 500 MeV Ar and 500 MeV Fe ions). The viability was evaluated by colony forming unit (cfu) counts as well as with the LIFE/DEAD kit. Results revealed that UV-C radiation (up to 1.000 J/m (2) ) has a considerable effect on the viability, whereas the other tested parameters inflict little damage onto the organisms. Repair of UV-C inflicted damage is efficient and several DNA damage repair genes are up-regulated following exposure. Halophilic archaea display a strong resistance against heavy iron bombardment, with dosages of up to 2.000 Gy 500 MeV Fe ions needed to establish a visible effect on the vitality. Genomic integrity after

  13. Environmental Conservation for Development and the Relevant Role of Education.

    ERIC Educational Resources Information Center

    Budowski, Gerardo

    Environmental education must be shaped to generate universal involvement in environmental aspects of life, in all political systems. It is absurd for political systems to attempt to adapt ecological factors to fit the underlying political assumptions; political philosophy must become consistent with ecological truths. In the developing nations it…

  14. Environmental Perception as a Diagnostic Probe of Environmental Complexity Levels

    ERIC Educational Resources Information Center

    Freitas, Mirlaine R.; Macedo, Renato L. G.; Freitas, Matheus P.; Nunes, Cleiton A.; Venturin, Nelson

    2015-01-01

    Purpose: Educational methods to diagnose and improve the level of environmental conception are required. The present work reports a methodology based on studies about the environmental perception of a university public, divided into general students and those related to the forest sciences, who are involved with disciplines and researches related…

  15. Environmental Perception as a Diagnostic Probe of Environmental Complexity Levels

    ERIC Educational Resources Information Center

    Freitas, Mirlaine R.; Macedo, Renato L. G.; Freitas, Matheus P.; Nunes, Cleiton A.; Venturin, Nelson

    2015-01-01

    Purpose: Educational methods to diagnose and improve the level of environmental conception are required. The present work reports a methodology based on studies about the environmental perception of a university public, divided into general students and those related to the forest sciences, who are involved with disciplines and researches related…

  16. Internationalisation and Standardisation of European Environmental Assessment. Relevance to India

    ERIC Educational Resources Information Center

    Gazzola, Paola; Jha-Thakur, Urmila

    2009-01-01

    This paper discusses the rationale underlying "PENTA", an EU funded Erasmus Mundus project. In doing so, it explores the challenges of internationalising and standardising European environmental assessment (EA) practice and education to a third country audience, looking at India as a case study. It is argued that the EU EA Directives are…

  17. Internationalisation and Standardisation of European Environmental Assessment. Relevance to India

    ERIC Educational Resources Information Center

    Gazzola, Paola; Jha-Thakur, Urmila

    2009-01-01

    This paper discusses the rationale underlying "PENTA", an EU funded Erasmus Mundus project. In doing so, it explores the challenges of internationalising and standardising European environmental assessment (EA) practice and education to a third country audience, looking at India as a case study. It is argued that the EU EA Directives are…

  18. Averaging underwater noise levels for environmental assessment of shipping.

    PubMed

    Merchant, Nathan D; Blondel, Philippe; Dakin, D Tom; Dorocicz, John

    2012-10-01

    Rising underwater noise levels from shipping have raised concerns regarding chronic impacts to marine fauna. However, there is a lack of consensus over how to average local shipping noise levels for environmental impact assessment. This paper addresses this issue using 110 days of continuous data recorded in the Strait of Georgia, Canada. Probability densities of ~10(7) 1-s samples in selected 1/3 octave bands were approximately stationary across one-month subsamples. Median and mode levels varied with averaging time. Mean sound pressure levels averaged in linear space, though susceptible to strong bias from outliers, are most relevant to cumulative impact assessment metrics.

  19. Biodegradation of nanocrystalline cellulose by two environmentally-relevant consortia.

    PubMed

    Singh, Gargi; Chandoha-Lee, Cody; Zhang, Wei; Renneckar, Scott; Vikesland, Peter J; Pruden, Amy

    2016-11-01

    Nanocellulose is growing in popularity due to its versatile properties and applications. However, there is a void of knowledge regarding the environmental fate of nanocellulose and the response of environmental microbial communities that are historically adapted to non-nano cellulose forms. Given its distinction in terms of size and chemical and physical properties, nanocellulose could potentially resist biodegradation and/or pose a xenobiotic influence on microbial communities during wastewater treatment or in receiving environments. In this study, biodegradation of H2SO4 hydrolyzed nanocrystalline cellulose (HNC) was compared with that of microcrystalline cellulose using two distinct anaerobic cellulose-degrading microbial consortia initially sourced from anaerobic digester (AD) and wetland (W) inocula. Equivalent cellulose masses were dosed and monitored with time by measurement of liberated glucose. HNC biodegraded at slightly faster rate than microcrystalline cellulose (1st order decay constants: 0.62 ± 0.08 wk(-1) for HNC versus 0.39 ± 0.05 wk(-1) for microcrystalline cellulose for the AD consortium; 0.69 ± 0.04 wk(-1)for HNCversus 0.58 ± 0.05 wk(-1) for microcrystalline cellulose for the W consortium). 16S rRNA (total bacteria) and cel48 (glycoside hydrolase gene family 48, indicative of cellulose-degrading potential) genes were observed to be more enriched in the HNC condition for both consortia. According to Illumina amplicon sequencing of 16S rRNA genes, the composition of the consortia underwent distinct shifts in concert with HNC versus microcrystalline cellulose degradation. This study demonstrates that the biodegradation of cellulose is not inhibited in the nano-size range, particularly in the crystalline form, though the microbes and pathways involved likely differ. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Environmentally relevant concentrations of nitrate increase plasma testosterone concentrations in female American alligators (Alligator mississippiensis).

    PubMed

    Hamlin, Heather J; Edwards, Thea M; McCoy, Jessica; Cruze, Lori; Guillette, Louis J

    2016-11-01

    Anthropogenic nitrogen is a ubiquitous environmental contaminant that is contributing to the degradation of freshwater, estuarine, and coastal ecosystems worldwide. The effects of environmental nitrate, a principal form of nitrogen, on the health of aquatic life is of increasing concern. We exposed female American alligators to three concentrations of nitrate (0.7, 10 and 100mg/L NO3-N) for a duration of five weeks and five months from hatch. We assessed growth, plasma sex steroid and thyroid hormone concentrations, and transcription levels of key genes involved in steroidogenesis (StAR, 3β-HSD, and P450scc) and hepatic clearance (Cyp1a, Cyp3a). Exposure to 100mg/L NO3-N for both five weeks and five months resulted in significantly increased plasma testosterone (T) concentrations compared with alligators in the reference treatment. No differences in 17β-estradiol, progesterone, or thyroid hormones were observed, nor were there differences in alligator weight or the mRNA abundance of steroidogenic or hepatic genes. Plasma and urinary nitrate concentrations increased with increasing nitrate treatment levels, although relative plasma concentrations of nitrate were significantly lower in five month, versus five week old animals, possibly due to improved kidney function in older animals. These results indicate that environmentally relevant concentrations of nitrate can increase circulating concentrations of T in young female alligators. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Mixtures of environmentally relevant endocrine disrupting chemicals affect mammary gland development in female and male rats.

    PubMed

    Mandrup, Karen Riiber; Johansson, Hanna Katarina Lilith; Boberg, Julie; Pedersen, Anne Stilling; Mortensen, Mette Sidsel; Jørgensen, Jennifer Solgaard; Vinggaard, Anne Marie; Hass, Ulla

    2015-07-01

    Estrogenic chemicals are able to alter mammary gland development in female rodents, but little is known on the effects of anti-androgens and mixtures of endocrine disrupting chemicals (EDCs) with dissimilar modes of action. Pregnant rat dams were exposed during gestation and lactation to mixtures of environmentally relevant EDCs with estrogenic, anti-androgenic or dissimilar modes of action (TotalMix) of 100-, 200- or 450-fold high end human intake estimates. Mammary glands of prepubertal and adult female and male offspring were examined. Oestrogens increased mammary outgrowth in prepubertal females and the mRNA level of matrix metalloproteinase-3, which may be a potential biomarker for increased outgrowth. Mixtures of EDCs gave rise to ductal hyperplasia in adult males. Adult female mammary glands of the TotalMix group showed morphological changes possibly reflecting increased prolactin levels. In conclusion both estrogenic and anti-androgenic chemicals given during foetal life and lactation affected mammary glands in the offspring.

  2. Transport of Fluorescently Labeled Hydroxyapatite Nanoparticles in Saturated Granular Media at Environmentally Relevant Concentrations of Surfactants

    EPA Science Inventory

    Little is known about the mobility of engineered nanoparticles (ENPs) in granular media at environmentally relevant concentration of surfactant, which represents a critical knowledge gap in employing ENPs for in-situ remediation of contaminated groundwater. In this study, transpo...

  3. Considerations of Environmentally Relevant Test Conditions for Improved Evaluation of Ecological Hazards of Engineered Nanomaterials

    EPA Science Inventory

    Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant ...

  4. Transport of Fluorescently Labeled Hydroxyapatite Nanoparticles in Saturated Granular Media at Environmentally Relevant Concentrations of Surfactants

    EPA Science Inventory

    Little is known about the mobility of engineered nanoparticles (ENPs) in granular media at environmentally relevant concentration of surfactant, which represents a critical knowledge gap in employing ENPs for in-situ remediation of contaminated groundwater. In this study, transpo...

  5. Considerations of Environmentally Relevant Test Conditions for Improved Evaluation of Ecological Hazards of Engineered Nanomaterials

    EPA Science Inventory

    Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant ...

  6. Designing a Quantitative Structure-Activity Relationship for the Intrinsic Metabolic Clearance of Environmentally Relevant Chemicals

    EPA Science Inventory

    Toxicokinetic models serve a vital role in risk assessment by bridging the gap between chemical exposure and potentially toxic endpoints. While intrinsic metabolic clearance rates have a strong impact on toxicokinetics, limited data is available for environmentally relevant chemi...

  7. Designing a Quantitative Structure-Activity Relationship for the Intrinsic Metabolic Clearance of Environmentally Relevant Chemicals

    EPA Science Inventory

    Toxicokinetic models serve a vital role in risk assessment by bridging the gap between chemical exposure and potentially toxic endpoints. While intrinsic metabolic clearance rates have a strong impact on toxicokinetics, limited data is available for environmentally relevant chemi...

  8. Effects of environmentally-relevant antibiotic mixtures on marine microalgal growth.

    PubMed

    Teixeira, Jaclyn R; Granek, Elise F

    2017-02-15

    As of 2008, approximately 48% of Americans use prescription drugs within any given 30-day period. Many pharmaceutical compounds are not fully metabolized by the human body, nor fully removed by wastewater treatment systems, before release into the environment. As a result, a vast array of pharmaceuticals has been detected in marine and freshwater organisms, sediments, and waters, with unintended effects on non-target organisms, and limited studies of environmental effects. The antibiotics sulfamethoxazole (SMX), and trimethoprim (TRI), often prescribed together to treat bacterial infections, have been detected worldwide in marine and estuarine environments at concentrations up to 765-870ng/L each. Little research has examined sub-lethal effects of antibiotic mixtures at environmentally-relevant concentrations on marine organisms. We examined the effects of mixtures of these two antibiotics on three marine microalgal species with wide geographic ranges: Isochrysis galbana, Chaetoceros neogracile, and Nannochloropsis oculata. In separate simulations using a temperature/light-controlled set-up, we measured the growth response for each species to environmentally-relevant levels of SMX and TRI. N. oculata growth was significantly reduced by mixture treatments of both drugs (p<0.05), by TRI (p<0.001), and by SMX (p<0.001), whereas only aggregated SMX levels significantly reduced growth for the other two species (p<0.005). The exposure time at which growth rates were affected varied across species, with significant reduction in growth focused in the latter half of the experimental period for C. neogracile and N. oculata (Days 15 and 6 respectively), and midway through the experimental period for I. galbana (by Day 3). This study finds that important marine primary producers respond to the presence of SMX and TRI in the water, offering an understanding of environmental consequences of anthropogenic pharmaceuticals contaminants, and specifically the suite of antibiotics

  9. The progestin levonorgestrel affects sex differentiation in zebrafish at environmentally relevant concentrations.

    PubMed

    Hua, Jianghuan; Han, Jian; Guo, Yongyong; Zhou, Bingsheng

    2015-09-01

    Synthetic progestins have become widespread environmental contaminants and may cause adverse effects on fish. In the present study, we investigated the effects of levonorgestrel (LNG) on sex differentiation in zebrafish (Danio rerio). Embryos were exposed to LNG at environmentally relevant concentrations (0, 1, 10, 33, and 100ng/L) and allowed to develop until sexual maturity. Histological examination at 63 days post fertilization (dpf) caused complete sex reversal and 100% males were observed in the 10, 33 and 100ng/L treatments; gross morphological and histological examination of gonads at 142dpf further confirmed 100% males at these exposure concentrations. The results indicate androgenic activity of LNG, and masculinization during zebrafish gonadal differentiation. The mRNA expression levels of genes involved in fish sex differentiation and gonadal development were examined at 28 and 42dpf. Down-regulation of the mRNA expression of aromatase (e.g., cyp19a1a, cyp19a1b), the forkhead transcription factor gene L2 (foxl2) and the Fushi tarazu factor-1d (nr5a1b) were observed. In contrast, transcription of the doublesex and mab-3-related transcription factor 1 (dmrt1) gene was up-regulated. Androgen receptor (ar) mRNA expression was significantly down-regulated at 28 and 42dpf. Co-exposure to flutamide (an androgen antagonist) and LNG, led to a decrease in the sex inversion potency of LNG. Our study has demonstrated that environmentally relevant concentrations of LNG could alter sex differentiation and gonadal development in zebrafish. Our results also suggest a potentially high ecological risk of LNG to fish populations in LNG-contaminated aquatic environments. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Toxicological responses in halophyte Suaeda salsa to mercury under environmentally relevant salinity.

    PubMed

    Wu, Huifeng; Liu, Xiaoli; Zhao, Jianmin; Yu, Junbao

    2012-11-01

    Mercury is a highly risky heavy metal contaminant in intertidal zones in the Yellow River Delta (YRD). Suaeda salsa is a native halophyte in the YRD. In this work, we investigated the toxicological effects of mercury (20μgL(-1)) in S. salsa under environmentally relevant salinity (500mM). The metabolic responses included the increased amino acids and decreased succinate, fructose, glucose, fumarate and ferulate in above-ground part of S. salsa exposed to mercury. The expression levels of INPS, CMO, BADH, CAT and GPx were elevated in above-ground part of S. salsa after combined Hg and salinity exposure. Increased activities of antioxidant enzymes including SOD, POD and CAT were uniquely observed in salinity-treated samples. Our results indicated potential oxidative stresses and disturbances in protein bio-degradation and energy metabolism induced by mercury in S. salsa. Additionally, both synergistic and antagonistic effects were observed in S. salsa exposed to combined mercury and salinity.

  11. Ecological relevance of Sentinels' biomarker responses: a multi-level approach.

    PubMed

    Seabra Pereira, Camilo D; Abessa, Denis M S; Choueri, Rodrigo B; Almagro-Pastor, Victor; Cesar, Augusto; Maranho, Luciane A; Martín-Díaz, María Laura; Torres, Ronaldo J; Gusso-Choueri, Paloma K; Almeida, João E; Cortez, Fernando S; Mozeto, Antonio A; Silbiger, Helcy L N; Sousa, Eduinetty C P M; Del Valls, Tommas Angel; Bainy, Afonso C D

    2014-05-01

    In response to the need for more sensitive and rapid indicators of environmental quality, sublethal effects on the lowest levels of biological organization have been investigated. The ecological relevance of these responses assumes a prevailing role to assure effectiveness as indicator of ecological status. This study aimed to investigate the linkages between biomarker responses of caged bivalves and descriptive parameters of macrobenthic community structure. For this purpose a multi-level environmental assessment of marine and estuarine zones was performed in São Paulo coast, Brazil. Multivariate analysis was applied to identify linkages between biological responses and ecological indices, as well as to characterizing the studied stations. Individuals of the marine mussel Perna perna caged along Santos Bay showed signs of oxidative stress, lysosomal membrane destabilization, histological alterations and reduced embryonic development. The estuarine oyster Crassostrea rhizophorae caged along Santos Port Channel showed alterations on biotransformation enzymes and antioxidant system, DNA damage and lysosomal membrane destabilization. The benthic community analysis showed reduced richness and diversity in the same areas of the Santos bay and estuary where biomarker responses were altered. Our results revealed that xenobiotics are inducing physiological stress, which may lead to changes of the benthic community structure and deterioration of the ecological status over time. Integrating biomarker responses and ecological indexes improved certainty that alterations found at community level could be related to xenobiotic as stressors, which was very useful to improve the discriminatory power of the environmental assessment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Ranking initial environmental and human health risk resulting from environmentally relevant nanomaterials.

    PubMed

    O'Brien, Niall; Cummins, Enda

    2010-01-01

    As nanomaterials find increased application in commercial and industrial products and processes so too the potential for release of these novel materials into the environment increases. The characteristics of these materials also may result in novel toxicological actions related to their nanoscale, which will have implications on their ecotoxicological and toxicological limits of exposure and eventual regulation. A framework for nanomaterial risk assessment on regulatory, ecotoxicological and toxicological bases developed from recent exposure and toxicity studies is presented. The release of nanoscale TiO(2), Ag and CeO(2) to the atmosphere and surface waters is assessed against provisional toxicological bench mark doses (BMDs) and critical effect doses (CEDs) developed from best available data. Predicted levels of nanomaterial release to surface waters and the atmosphere resulted in regulatory risk rankings of moderate concern based on worst case provisional regulatory limits. Inhalation and ingestion risk rankings were of very low concern based on the provisional inhalation and ingestion toxicity BMDLs and CEDLs determined for the nanomaterials in question. More toxicological data is needed on nanoscale CeO(2) inhalation to develop a true dose response as in vitro cytotoxicity studies yielded an inhalation risk ranking of lower concern. The moderate to high ecotoxicological risk rankings posed by the release of nanoscale TiO(2) and Ag to surface waters highlights the need for guidance and restriction on the usage and disposal of commercial products containing nanomaterial. The risk rankings presented in this assessment give a first indication of the relative risks posed by the usage and release of these materials into the environment and indicate what materials require further investigation into their nano-specific toxicological actions. As more nano-relevant toxicity studies are published, end-points and risk levels related to nano-specific toxicity actions may

  13. Intergenerational equity and environmental restoration cleanup levels.

    SciTech Connect

    Hocking, E. K.; Environmental Assessment

    2001-01-01

    The United States Department of Energy environmental restoration program faces difficult decisions about the levels of cleanup to be achieved at its many contaminated sites and has acknowledged the need for considering intergenerational equity in its decision making. Intergenerational equity refers to the fairness of access to resources across generations. Environmental restoration cleanup levels can have unintended and unfair consequences for future generations access to resources. The potentially higher costs associated with using low, non-risk-based cleanup levels for remediation may divert funding from other activities that could have a greater beneficial impact on future generations. Low, non-risk-based cleanup levels could also result in more damage to the nation's resources than would occur if a higher cleanup level were used. The loss or impairment of these resources could have an inequitable effect on future generations. However, intergenerational inequity could arise if sites are not completely restored and if access to and use of natural and cultural resources are unfairly limited as a result of residual contamination. In addition to concerns about creating possible intergenerational inequities related to selected cleanup levels, the tremendous uncertainties associated with sites and their restoration can lead site planners to rely on stewardship by default. An ill-conceived stewardship program can contribute to intergenerational inequity by limiting access to resources while passing on risks to future generations and not preparing them for those risks. This paper presents a basic model and process for designing stewardship programs that can achieve equity among generations.

  14. Considerations of Environmentally Relevant Test Conditions for Improved Evaluation of Ecological Hazards of Engineered Nanomaterials.

    PubMed

    Holden, Patricia A; Gardea-Torresdey, Jorge L; Klaessig, Fred; Turco, Ronald F; Mortimer, Monika; Hund-Rinke, Kerstin; Cohen Hubal, Elaine A; Avery, David; Barceló, Damià; Behra, Renata; Cohen, Yoram; Deydier-Stephan, Laurence; Ferguson, P Lee; Fernandes, Teresa F; Herr Harthorn, Barbara; Henderson, W Matthew; Hoke, Robert A; Hristozov, Danail; Johnston, John M; Kane, Agnes B; Kapustka, Larry; Keller, Arturo A; Lenihan, Hunter S; Lovell, Wess; Murphy, Catherine J; Nisbet, Roger M; Petersen, Elijah J; Salinas, Edward R; Scheringer, Martin; Sharma, Monita; Speed, David E; Sultan, Yasir; Westerhoff, Paul; White, Jason C; Wiesner, Mark R; Wong, Eva M; Xing, Baoshan; Steele Horan, Meghan; Godwin, Hilary A; Nel, André E

    2016-06-21

    Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant concentrations-where observing outcomes is difficult-versus higher ENM doses, where responses are observable. What exposure conditions are typically used in assessing ENM hazards to populations? What conditions are used to test ecosystem-scale hazards? What is known regarding actual ENMs in the environment, via measurements or modeling simulations? How should exposure conditions, ENM transformation, dose, and body burden be used in interpreting biological and computational findings for assessing risks? These questions were addressed in the context of this critical review. As a result, three main recommendations emerged. First, researchers should improve ecotoxicology of ENMs by choosing test end points, duration, and study conditions-including ENM test concentrations-that align with realistic exposure scenarios. Second, testing should proceed via tiers with iterative feedback that informs experiments at other levels of biological organization. Finally, environmental realism in ENM hazard assessments should involve greater coordination among ENM quantitative analysts, exposure modelers, and ecotoxicologists, across government, industry, and academia.

  15. Toxicity of a dissolved pyrethroid mixture to Hyalella azteca at environmentally relevant concentrations.

    PubMed

    Brander, Susanne M; Werner, Inge; White, J Wilson; Deanovic, Linda A

    2009-07-01

    Use of pyrethroid pesticides, which are highly toxic to aquatic organisms, has increased substantially over the past decade. In 2006, the pyrethroid pesticides cyfluthrin and permethrin were measured in Sacramento-San Joaquin (SSJ) Delta (CA, USA) water at 5 and 24 ng/L (pptr), respectively. To elucidate any interactions between the two pyrethroids, a 10-d laboratory exposure was performed with 7- to 14-d-old amphipods (Hyalella azteca). Cyfluthrin and permethrin were tested singly and in combination at detected levels and also at half and twice the detected levels, both with and without the addition of 25 ppb of piperonyl butoxide (PBO). Mortality in all treatments was significantly higher than in controls, with the median lethal concentration (LC50) for permethrin with PBO (13.9 ng/L) and the LC50s with and without PBO for cyfluthrin (5.7 and 2.9 ng/L, respectively) at or below levels measured in SSJ Delta water samples. The LC50 for permethrin alone was estimated to be 48.9 ng/L. To evaluate combined toxicity, logistic regression models containing terms for concentrations of cyfluthrin, permethrin, and PBO, as well as models containing all possible combinations of these terms and interactions, were run and compared using Akaike's information criterion. The most parsimonious set of models indicated slight antagonism between cyfluthrin and permethrin. Results indicate that a dissolved mixture of cyfluthrin and permethrin is toxic at environmentally relevant concentrations in the water column.

  16. Behavioural and physiological responses of birds to environmentally relevant concentrations of an antidepressant

    PubMed Central

    Bean, Tom G.; Boxall, Alistair B. A.; Lane, Julie; Herborn, Katherine A.; Pietravalle, Stéphane; Arnold, Kathryn E.

    2014-01-01

    Many wildlife species forage on sewage-contaminated food, for example, at wastewater treatment plants and on fields fertilized with sewage sludge. The resultant exposure to human pharmaceuticals remains poorly studied for terrestrial species. On the basis of predicted exposure levels in the wild, we administered the common antidepressant fluoxetine (FLUOX) or control treatment via prey to wild-caught starlings (Sturnus vulgaris) for 22 weeks over winter. To investigate responses to fluoxetine, birds were moved from their group aviaries into individual cages for 2 days. Boldness, exploration and activity levels showed no treatment effects but controls and FLUOX birds habituated differently to isolation in terms of the concentration of corticosterone (CORT) metabolites in faeces. The controls that excreted higher concentrations of CORT metabolites on day 1 lost more body mass by day 2 of isolation than those which excreted lower levels of CORT metabolites. CORT metabolites and mass loss were unrelated in FLUOX birds. When we investigated the movements of birds in their group aviaries, we found the controls made a higher frequency of visits to food trays than FLUOX birds around the important foraging periods of sunrise and sunset, as is optimal for wintering birds. Although individual variability makes interpreting the sub-lethal endpoints measured challenging, our data suggest that fluoxetine at environmentally relevant concentrations can significantly alter behaviour and physiology. PMID:25405964

  17. LINK BETWEEN LOW-DOSE ENVIRONMENTALLY RELEVANT CADMIUM EXPOSURES AND ASTHENOZOOSPERMIA IN A RAT MODEL

    PubMed Central

    Benoff, Susan; Auborn, Karen; Marmar, Joel L.; Hurley, Ian R.

    2008-01-01

    Objective To define the mechanism(s) underlying an association between asthenozoospermia and elevated blood, seminal plasma and testicular cadmium levels in infertile human males using a rat model of environmentally relevant cadmium exposures. Setting University medical center andrology research laboratory. Animals Male Wistar rats (n = 60), documented to be sensitive to the testicular effects of cadmium. Interventions Rats were given ad libitum access to water supplemented with 14% sucrose and 0, 5, 50 or 100 mg/L cadmium for 1, 4 or 8 weeks being at puberty. Main outcome measure(s) Testicular cadmium levels were determined by atomic absorption, cauda epididymal sperm motility by visual inspection, and testicular gene expression by DNA microarray hybridization. Results Chronic, low dose cadmium exposures produced a time- and dose-dependent reduction in sperm motility. Transcription of genes regulated by calcium and expression of L-type voltage-dependent calcium channel mRNA splicing variants were altered by cadmium exposure. Expression of calcium binding proteins involved in modulation of sperm motility was unaffected. Conclusions A causal relationship between elevated testicular cadmium and asthenozoospermia was identified. Aberrrant sperm motility was correlated with altered expression of L-type voltage-dependent calcium channel isoforms found on the sperm tail, which regulate calcium and cadmium influx. PMID:18308070

  18. More than a Museum: Natural History is Relevant in 21st Century Environmental Science

    NASA Astrophysics Data System (ADS)

    Hernandez, R. R.; Murphy-Mariscal, M. L.; Barrows, C. W.

    2015-12-01

    In the Anthropocene, the relevancy of natural history in environmental science is challenged and marginalized today more than ever. We tested the hypothesis that natural history is relevant to the fields of environmental science and ecology by assessing the values, needs, and decisions related to natural history of graduate students and environmental science professionals across 31 universities and various employers, respectively, in California. Graduate students surveyed (93.3%) agreed that natural history was relevant to science, approximately 70% believed it "essential" for conducting field-based research; however, 54.2% felt inadequately trained to teach a natural history course and would benefit from additional training in natural history (> 80%). Of the 185 professionals surveyed, all felt that natural history was relevant to science and "essential" or "desirable" in their vocation (93%). Our results indicate a disconnect between the value and relevancy of natural history in 21st century ecological science and opportunities for gaining those skills and knowledge through education and training.

  19. Physiological relevance of plant 2-Cys peroxiredoxin overoxidation level and oligomerization status.

    PubMed

    Cerveau, Delphine; Ouahrani, Djelloul; Marok, Mohamed Amine; Blanchard, Laurence; Rey, Pascal

    2016-01-01

    Peroxiredoxins are ubiquitous thioredoxin-dependent peroxidases presumed to display, upon environmental constraints, a chaperone function resulting from a redox-dependent conformational switch. In this work, using biochemical and genetic approaches, we aimed to unravel the factors regulating the redox status and the conformation of the plastidial 2-Cys peroxiredoxin (2-Cys PRX) in plants. In Arabidopsis, we show that in optimal growth conditions, the overoxidation level mainly depends on the availability of thioredoxin-related electron donors, but not on sulfiredoxin, the enzyme reducing the 2-Cys PRX overoxidized form. We also observed that upon various physiological temperature, osmotic and light stress conditions, the overoxidation level and oligomerization status of 2-Cys PRX can moderately vary depending on the constraint type. Further, no major change was noticed regarding protein conformation in water-stressed Arabidopsis, barley and potato plants, whereas species-dependent up- and down-variations in overoxidation were observed. In contrast, both 2-Cys PRX overoxidation and oligomerization were strongly induced during a severe oxidative stress generated by methyl viologen. From these data, revealing that the oligomerization status of plant 2-Cys PRX does not exhibit important variation and is not tightly linked to the protein redox status upon physiologically relevant environmental constraints, the possible in planta functions of 2-Cys PRX are discussed. © 2015 John Wiley & Sons Ltd.

  20. Review of Antimicrobial Resistance in the Environment and Its Relevance to Environmental Regulators.

    PubMed

    Singer, Andrew C; Shaw, Helen; Rhodes, Vicki; Hart, Alwyn

    2016-01-01

    The environment is increasingly being recognized for the role it might play in the global spread of clinically relevant antibiotic resistance. Environmental regulators monitor and control many of the pathways responsible for the release of resistance-driving chemicals into the environment (e.g., antimicrobials, metals, and biocides). Hence, environmental regulators should be contributing significantly to the development of global and national antimicrobial resistance (AMR) action plans. It is argued that the lack of environment-facing mitigation actions included in existing AMR action plans is likely a function of our poor fundamental understanding of many of the key issues. Here, we aim to present the problem with AMR in the environment through the lens of an environmental regulator, using the Environment Agency (England's regulator) as an example from which parallels can be drawn globally. The issues that are pertinent to environmental regulators are drawn out to answer: What are the drivers and pathways of AMR? How do these relate to the normal work, powers and duties of environmental regulators? What are the knowledge gaps that hinder the delivery of environmental protection from AMR? We offer several thought experiments for how different mitigation strategies might proceed. We conclude that: (1) AMR Action Plans do not tackle all the potentially relevant pathways and drivers of AMR in the environment; and (2) AMR Action Plans are deficient partly because the science to inform policy is lacking and this needs to be addressed.

  1. Review of Antimicrobial Resistance in the Environment and Its Relevance to Environmental Regulators

    PubMed Central

    Singer, Andrew C.; Shaw, Helen; Rhodes, Vicki; Hart, Alwyn

    2016-01-01

    The environment is increasingly being recognized for the role it might play in the global spread of clinically relevant antibiotic resistance. Environmental regulators monitor and control many of the pathways responsible for the release of resistance-driving chemicals into the environment (e.g., antimicrobials, metals, and biocides). Hence, environmental regulators should be contributing significantly to the development of global and national antimicrobial resistance (AMR) action plans. It is argued that the lack of environment-facing mitigation actions included in existing AMR action plans is likely a function of our poor fundamental understanding of many of the key issues. Here, we aim to present the problem with AMR in the environment through the lens of an environmental regulator, using the Environment Agency (England’s regulator) as an example from which parallels can be drawn globally. The issues that are pertinent to environmental regulators are drawn out to answer: What are the drivers and pathways of AMR? How do these relate to the normal work, powers and duties of environmental regulators? What are the knowledge gaps that hinder the delivery of environmental protection from AMR? We offer several thought experiments for how different mitigation strategies might proceed. We conclude that: (1) AMR Action Plans do not tackle all the potentially relevant pathways and drivers of AMR in the environment; and (2) AMR Action Plans are deficient partly because the science to inform policy is lacking and this needs to be addressed. PMID:27847505

  2. Impairment of the reproductive potential of male fathead minnows by environmentally relevant exposures to 4-nonylphenolf

    USGS Publications Warehouse

    Schoenfuss, H.L.; Bartell, S.E.; Bistodeau, T.B.; Cediel, R.A.; Grove, K.J.; Zintek, L.; Lee, K.E.; Barber, L.B.

    2008-01-01

    The synthetic organic compound 4-nonylphenol (NP) has been detected in many human-impacted surface waters in North America. In this study, we examined the ability of NP to alter reproductive competence in male fathead minnows after a 28 day flow-through exposure in a range of environmentally relevant concentrations bracketing the U.S. Environmental Protection Agency toxicity-based NP chronic exposure criterion of 6.1 ??g NP/L. Exposure to NP at and above the EPA chronic exposure criterion resulted in an induction of plasma vitellogenin (VTG) within 14 days. However, 7 days after the cessation of exposure, VTG concentrations had dropped more than 50% and few males expressed VTG above the detection threshold. All of the morphological endpoints, including gonadosomatic index, hepatosomatic index, secondary sexual characters, and histopathology, were unaltered by all NP treatments. However, when NP-exposed male fish were allowed to compete with control males for access to nest sites and females, most treatments altered the reproductive competence of exposed males. At lower NP concentrations, exposed males out-competed control males, possibly by being primed through the estrogenic NP exposure in a fashion similar to priming by pheromones released from female fathead minnows. At higher NP exposure concentrations, this priming effect was negated by the adverse effects of the exposure and control males out-competed treated males. Results of this study indicate the complexity of endocrine disrupting effects and the need for multiple analysis levels to assess the effects of these compounds on aquatic organisms. ?? 2007 Elsevier B.V. All rights reserved.

  3. Organismal climatology: analyzing environmental variability at scales relevant to physiological stress.

    PubMed

    Helmuth, Brian; Broitman, Bernardo R; Yamane, Lauren; Gilman, Sarah E; Mach, Katharine; Mislan, K A S; Denny, Mark W

    2010-03-15

    Predicting when, where and with what magnitude climate change is likely to affect the fitness, abundance and distribution of organisms and the functioning of ecosystems has emerged as a high priority for scientists and resource managers. However, even in cases where we have detailed knowledge of current species' range boundaries, we often do not understand what, if any, aspects of weather and climate act to set these limits. This shortcoming significantly curtails our capacity to predict potential future range shifts in response to climate change, especially since the factors that set range boundaries under those novel conditions may be different from those that set limits today. We quantitatively examine a nine-year time series of temperature records relevant to the body temperatures of intertidal mussels as measured using biomimetic sensors. Specifically, we explore how a 'climatology' of body temperatures, as opposed to long-term records of habitat-level parameters such as air and water temperatures, can be used to extrapolate meaningful spatial and temporal patterns of physiological stress. Using different metrics that correspond to various aspects of physiological stress (seasonal means, cumulative temperature and the return time of extremes) we show that these potential environmental stressors do not always occur in synchrony with one another. Our analysis also shows that patterns of animal temperature are not well correlated with simple, commonly used metrics such as air temperature. Detailed physiological studies can provide guidance to predicting the effects of global climate change on natural ecosystems but only if we concomitantly record, archive and model environmental signals at appropriate scales.

  4. Designing at Scale: Lessons in Relevance, Quality, and Equity from ChangeScale, a Bay Area environmental education collaborative

    NASA Astrophysics Data System (ADS)

    Babcock, E.

    2015-12-01

    The best environmental education equips people with the know-how and drive to create healthy communities and a healthy planet. While there are many wonderful organizations providing environmental learning, ensuring quality, cultural relevance and equity of access remains an elusive goal--especially if environmental education organizations work in isolation. Organizations across 12 counties in the Bay Area have come together to create a different model. They have founded ChangeScale, a regional collaborative dedicated to providing high quality environmental education to hundreds of thousands of youth---by working together. ChangeScale's work involves setting up school district-level partnerships, providing technical assistance to local environmental education networks, and training environmental educators across the region. In this talk, the presenter, who is a founding member and steering committee chair for ChangeScale, will outline the challenges of working at a regional scale with dozens of organizations. She will share the processes ChangeScale has used to develop a business plan and build membership. She will conclude by sharing the short term and long term potential impacts of working collectively for environmental literacy in the Bay Area.

  5. Bioconcentration pattern and induced apoptosis of bisphenol A in zebrafish embryos at environmentally relevant concentrations.

    PubMed

    Wu, Minghong; Pan, Chenyuan; Chen, Zhong; Jiang, Lihui; Lei, Penghui; Yang, Ming

    2017-03-01

    Bisphenol A (BPA) is a well-known endocrine-disrupting chemical that is ubiquitously present in the environment. In the present study, 4-h post-fertilization (hpf) zebrafish embryos were exposed to various environmentally relevant concentrations of BPA (0.1, 1, 10, 100, and 1000 μg/L) until 72 and 168 hpf, and the accumulation pattern of BPA and its potential to induce toxicity through apoptosis were determined. Compared to BPA concentrations in larvae at 168 hpf, BPA concentrations in embryos exposed until 72 hpf were at relatively higher levels (p < 0.05) with higher bioconcentration factor (BCF) values. The nonlinear fitting analysis indicated that the BCF values of BPA in fish embryos/larvae were significantly correlated to the log10-transformed BPA exposure concentrations in water in an inverse concentration-dependent manner. Fish accumulated more BPA as the exposure concentrations increased; however, their accumulation capacity of BPA declined and tended to be saturated in the high exposure groups of BPA. Moreover, caspase-3 activity was significantly induced upon BPA exposure at 0.1, 1, 10, and 100 μg/L BPA at 72 hpf, and also at 10 and 100 μg/L BPA at 168 hpf. Correspondingly, exposure to 10 and 100 μg/L of BPA significantly increased the DNA fragmentation in the extracted DNA at 168 hpf as determined by DNA ladder analysis. In addition, the expression patterns of four genes related to apoptosis including caspase-3, bax, p53, and c-jun were significantly up-regulated (p < 0.05) in fish embryos/larvae upon BPA exposure at 72 and 168 hpf. Our results revealed that low and environmentally relevant concentrations of BPA could be significantly accumulated in zebrafish and induced apoptosis with involvement of the regulation of caspase-3 and other apoptosis-related genes.

  6. Responses of laboratory exposed catfish (Clarias gariepinus) to environmentally relevant concentrations of p,p'-DDT.

    PubMed

    Brink, Kerry; van Vuren, Johan; Bornman, Riana

    2012-11-01

    Technical grade DDT is annually sprayed for malaria control in many under developed countries world wide. Despite the controversy surrounding the use of DDT, minimal research concerning the effects on indigenous fish species in these areas has been conducted. In this study, the objectives were to identify some of the effects of sprayed p,p'-DDT on the common African sharptooth catfish species (Clarias gariepinus) under laboratory conditions. The effects were assessed by exposing specimens to three environmentally relevant concentrations of p,p'-DDT (0.66, 1.36 and 2.72 μg/l) for 21 days and analysing a suite of biomarkers in the plasma, gonads and body morphometrics. The biomarkers were specifically selected based on their practicality in developing countries, which could potentially be utilised for continued monitoring, and included alkali-labile phosphate (ALP), calcium, magnesium and zinc as the indirect measures of vitellogenin, gonadosomatic index, gonad mass manipulated using analysis of covariance, and condition factor. The results showed no significant (p<0.05) dose-dependent changes in the plasma, gonads and body condition of C. gariepinus, indicating that these species were not responsive to the p,p'-DDT concentrations when exposed sub-chronically. This lack of a response suggested that mature C. gariepinus are tolerant to 21 days exposure of low levels of p,p'-DDT.

  7. Metformin exposure at environmentally relevant concentrations causes potential endocrine disruption in adult male fish.

    PubMed

    Niemuth, Nicholas J; Jordan, Renee; Crago, Jordan; Blanksma, Chad; Johnson, Rodney; Klaper, Rebecca D

    2015-02-01

    Pharmaceuticals and personal care products (PPCPs) are emerging contaminants that have been found ubiquitously in wastewater and surface waters around the world. A major source of these compounds is incomplete metabolism in humans and subsequent excretion in human waste, resulting in discharge into surface waters by wastewater treatment plant (WWTP) effluent. One pharmaceutical found in particularly high abundance in recent WWTP effluent and surface water studies is metformin, one of the world's most widely prescribed antidiabetic drugs. Interactions between insulin signaling and steroidogenesis suggest potential endocrine-disrupting effects of metformin found in the aquatic environment. Adult fathead minnows (Pimephales promelas) were chronically exposed to metformin for 4 wk, at 40 µg/L, a level similar to the average found in WWTP effluent in Milwaukee, Wisconsin, USA. Genetic endpoints related to metabolism and endocrine function as well as reproduction-related endpoints were examined. Metformin treatment induced significant up-regulation of messenger ribonucleic acid (mRNA) encoding the egg-protein vitellogenin in male fish, an indication of endocrine disruption. The present study, the first to study the effects of environmentally relevant metformin exposure in fathead minnows, demonstrates the need for further study of the endocrine-disrupting effects of metformin in aquatic organisms.

  8. Metformin Exposure at Environmentally Relevant Concentrations Causes Potential Endocrine Disruption in Adult Male Fish

    PubMed Central

    Niemuth, Nicholas J; Jordan, Renee; Crago, Jordan; Blanksma, Chad; Johnson, Rodney; Klaper, Rebecca D

    2015-01-01

    Pharmaceuticals and personal care products (PPCPs) are emerging contaminants that have been found ubiquitously in wastewater and surface waters around the world. A major source of these compounds is incomplete metabolism in humans and subsequent excretion in human waste, resulting in discharge into surface waters by wastewater treatment plant (WWTP) effluent. One pharmaceutical found in particularly high abundance in recent WWTP effluent and surface water studies is metformin, one of the world's most widely prescribed antidiabetic drugs. Interactions between insulin signaling and steroidogenesis suggest potential endocrine-disrupting effects of metformin found in the aquatic environment. Adult fathead minnows (Pimephales promelas) were chronically exposed to metformin for 4 wk, at 40 µg/L, a level similar to the average found in WWTP effluent in Milwaukee, Wisconsin, USA. Genetic endpoints related to metabolism and endocrine function as well as reproduction-related endpoints were examined. Metformin treatment induced significant up-regulation of messenger ribonucleic acid (mRNA) encoding the egg-protein vitellogenin in male fish, an indication of endocrine disruption. The present study, the first to study the effects of environmentally relevant metformin exposure in fathead minnows, demonstrates the need for further study of the endocrine-disrupting effects of metformin in aquatic organisms. Environ Toxicol Chem 2014;9999:1–6. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of SETAC. PMID:25358780

  9. Altered pairing behaviour and reproductive success in white ibises exposed to environmentally relevant concentrations of methylmercury

    PubMed Central

    Frederick, Peter; Jayasena, Nilmini

    2011-01-01

    Methylmercury (MeHg) is the most biologically available and toxic form of mercury, and can act as a powerful teratogen, neurotoxin and endocrine disruptor in vertebrates. However, mechanisms of endocrine impairment and net effects on demography of biota are poorly understood. Here, we report that experimental exposure of an aquatic bird over 3 years to environmentally relevant dietary MeHg concentrations (0.05–0.3 ppm wet weight) resulted in dose-related increases in male–male pairing behaviour (to 55% of males), and decreases in egg productivity (to 30%). Dosed males showed decreased rates of key courtship behaviours, and were approached less by courting females in comparison to control males. Within dosed groups, homosexual males showed a similar reduction when compared with dosed heterosexual males. We found an average 35 per cent decrease in fledgling production in high-dose birds over the study duration. These results are of interest because (i) MeHg exposure is experimentally tied to demographically important reproductive deficits, (ii) these effects were found at low, chronic exposure levels commonly experienced by wildlife, and (iii) effects on reproductive behaviour and sexual preference mediated by endocrine disruption represent a novel and probably under-reported mechanism by which contaminants may influence wild populations of birds. PMID:21123262

  10. Effects of glyphosate at environmentally relevant concentrations on the growth of and microcystin production by Microcystis aeruginosa.

    PubMed

    Zhang, Quan; Zhou, Hang; Li, Zhe; Zhu, Jianqiang; Zhou, Cong; Zhao, Meirong

    2016-11-01

    The use of glyphosate, which is a well-known sterilant herbicide, has been growing rapidly because the area under the cultivation of genetically modified crops that are tolerant to this herbicide has increased. Glyphosate can enter into aquatic systems through many different ways. However, information on the potential risks of glyphosate at environmentally relevant levels to aquatic systems is still limited. In this study, we selected the cyanobacterium Microcystis aeruginosa FACHB-905 (M. aeruginosa) as a model organism to evaluate the effects of glyphosate at environmentally relevant concentrations on the former's growth and microcystin (MC) production. Our results show that low levels of glyphosate stimulate the growth of M. aeruginosa. Subsequently, there was significant increase in the total MC-LR and intracellular MC-LR, but not in extracellular MC-LR, after exposure to 0.1-2 mg/L of glyphosate. The increase in total MC-LR is mainly due to the effects of glyphosate on the cell density of M. aeruginosa. The data provided here show that low level of glyphosate in a water body is a potential environmental risk factor that stimulates the growth and enhances MC production in M. aeruginosa, which should arouse great concern.

  11. Potential CERCLA reauthorization issues relevant to US DOE`s Environmental Restoration Program

    SciTech Connect

    Siegel, M.R.; McKinney, M.D.; Jaksch, J.A.; Dailey, R.L.

    1993-02-01

    The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) is currently scheduled to be reauthorized in 1994. The US Department of Energy (DOE) has a significant stake in CERCLA reauthorization. CERCLA, along with its implementing regulation, the National Contingency Plan (NCP), is the principal legal authority governing DOE`s environmental restoration program. The manner in which CERCLA-related issues are identified, evaluated, and dispatched may have a substantial impact on DOE`s ability to conduct its environmental restoration program. A number of issues that impact DOE`s environmental restoration program could be addressed through CERCLA reauthorization. These issues include the need to (1) address how the National Environmental Policy Act (NEPA) should be integrated into DOE CERCLA actions, (2) facilitate the streamlining of the Superfund process at DOE sites, (3) address the conflicts between the requirements of CERCLA and the Resource Conservation and Recovery Act (RCRA) that are especially relevant to DOE, (4) examine the criteria for waiving applicable or relevant and appropriate requirements (ARARs) at DOE sites, and (5) delineate the appropriate use of institutional controls at DOE sites.

  12. Environmentally relevant exposure to 17α-ethinylestradiol affects the telencephalic proteome of male fathead minnows

    PubMed Central

    Martyniuk, Christopher J.; Kroll, Kevin J.; Doperalski, Nicholas J.; Barber, David S.; Denslow, Nancy D.

    2010-01-01

    Estrogens are key mediators of neuronal processes in vertebrates. As such, xenoestrogens present in the environment have the potential to alter normal central nervous system (CNS) function. The objectives of the present study were 1) to identify proteins with altered expression in the male fathead minnow telencephalon as a result of low level exposure to 17α-ethinylestradiol (EE2), and 2) to better understand the underlying mechanisms of 17β-estradiol (E2) feedback in this important neuroendocrine tissue. Male fathead minnows exposed to a measured concentration of 5.4 ng EE2/L for 48 hours showed decreased plasma E2 levels of approximately 2-fold. Of 77 proteins that were quantified statistically, 14 proteins were down-regulated after EE2 exposure, including four histone proteins, ATP synthase, H+ transporting subunits, and metabolic proteins (lactate dehydrogenase B4, malate dehydrogenase 1b). Twelve proteins were significantly induced by EE2 including microtubule-associated protein tau (MAPT), astrocytic phosphoprotein, ependymin precursor, and calmodulin. MAPT showed an increase in protein abundance but a decrease in mRNA expression after EE2 exposure, suggesting there may be a negative feedback response in the telencephalon to decrease mRNA transcription with increasing MAPT protein abundance. These results demonstrate that a low, environmentally relevant exposure to EE2 can rapidly alter the abundance of proteins involved in cell differentiation and proliferation, neuron network morphology, and long term synaptic potentiation. Together, these findings provide a better understanding of the molecular responses underlying E2 feedback in the brain and demonstrate that quantitative proteomics can be successfully used in ecotoxicology to characterize affected cellular pathways and endocrine physiology. PMID:20381887

  13. Relevance of Bt toxin interaction studies for environmental risk assessment of genetically modified crops.

    PubMed

    De Schrijver, Adinda; De Clercq, Patrick; de Maagd, Ruud A; van Frankenhuyzen, Kees

    2015-12-01

    In recent years, different Bacillus thuringiensis (Bt) toxin-encoding genes have been combined or 'stacked' in genetically modified (GM) crops. Synergism between Bt proteins may occur and thereby increase the impact of the stacked GM event on nontarget invertebrates compared to plants expressing a single Bt gene. On the basis of bioassay data available for Bt toxins alone or in combination, we argue that the current knowledge of Bt protein interactions is of limited relevance in environmental risk assessment (ERA).

  14. Studies of the surface reactivity of metal oxyhydroxides and sulfides with relevance to environmental chemistry

    NASA Astrophysics Data System (ADS)

    Pierre-Louis, Andro-Marc

    With the benefits of an ever increasing advance of industrialization around the globe come formidable environmental problems. Three environmental problems that have relevance to the research described in this thesis are the 1) buildup of atmospheric CO2 gas through the burning of fossil fuels, 2) eutrophication of aquatic systems, and 3) the acidification of environments from acid mine drainage (AMD) resulting from coal-mining activities. In particular research is presented in this thesis that investigated the surface chemistry of CO2 and phosphate (PO43-) on a suite of environmentally relevant iron oxyhydroxide materials and the chemistry of phospholipid molecules on environmentally relevant iron sulfide surfaces to suppress AMD. To develop a microscopic understanding of the surface chemistry of the different systems, an array of experimental and computational techniques were used in the research. Techniques included X-ray photoelectron spectroscopy, atomic adsorption, X-ray diffraction, scanning transmission microscopy with electron dispersive X-ray spectroscopy (STEM/EDS), ion chromatography (IC), and attenuated total reflectance Fourier transform Infrared (ATR-FTIR). Results from the latter technique were interpreted with the aid of density function theory (DFT) calculations. Iron oxyhydroxides, which consisted of ferrihydrite (FeOOH), goethite (α-FeOOH), ferrimagnetic ferrihydrite (FerriFh), and aluminum-doped iron oxyhydroxide (content from 0-100 mol%) were synthesized and studied before and after exposure to gaseous CO2, CO32-, and PO43- species. FeOOH and mixed Al/Fe oxyhydroxide surfaces showed high affinities for the formation of carbonate and bicarbonate species upon exposure to gaseous CO2. Within the Al/Fe oxyhydroxide circumstance, a low Al level of incorporation in the iron oxyhydroxide structure caused a slight increase in surface area and increase in the amount of oxyanion (e.g., CO32- or PO43-) adsorption up to an Al level of 30 mol%. Significant

  15. Environmentally relevant concentrations of a common insecticide increase predation risk in a freshwater gastropod.

    PubMed

    Salice, Christopher J; Kimberly, David A

    2013-01-01

    Ecological receptors are faced with a multitude of stressors that include abiotic and biotic factors creating a challenge for assessing risk of chemical exposure. Of particular interest and importance are the effects of contaminants on inter-species interactions such as competition and predator-prey relationships. The objective of this study was to determine whether environmentally relevant concentrations of the commonly used insecticide, malathion, would alter predator avoidance behavior in a freshwater gastropod that could translate to increased predation risk. We exposed adult Physa pomilia snails to 0, 0.25, or 1.0 mg/L malathion for 2, 24, or 48 h and evaluated predator avoidance using a behavioral assay in which snails were exposed to cues from predatory crayfish. We found a significant reduction in predator avoidance in snails exposed to both concentrations of malathion after 48 h of exposure. To evaluate whether observed effects of malathion on predator avoidance actually increased susceptibility of snails to predators, we conducted a predator challenge experiment. Snails exposed to 0.25 mg/L malathion for 48 h were significantly more susceptible to predation. That increased predation risk was evident 48 h after initial malathion exposures is a unique result because most studies have evaluated behavioral responses soon after (<12 h) initiation of pesticide exposure. The extent to which the observed interactions affect natural populations, and the mechanisms through which they are mediated are largely unexplored. However, our study is the first to show that a commonly used insecticide decreases predator avoidance and may actually increase predation susceptibility in gastropods at concentrations several orders of magnitude below acute toxicity levels.

  16. Base-catalyzed reactions of environmentally relevant N-chloro-piperidines. A quantum-chemical study.

    PubMed

    Šakić, Davor; Zipse, Hendrik; Vrček, Valerije

    2011-06-07

    Electronic structure methods have been applied to calculate the gas and aqueous phase reaction energies for base-induced rearrangements of N-chloropiperidine, N-chloro-3-(hydroxymethyl)piperidine, and N-chloro-4-(4-fluorophenyl)-3-(hydroxymethyl)piperidine. These derivatives have been selected as representative models for studying the chemical fate of environmentally relevant chloramines. The performance of different computational methods (MP2, MP4, QCISD, B3LYP and B2PLYP) for calculating the thermochemistry of rearrangement reactions was assessed. The latter method produces energies similar to those obtained at G3B3(+) level, which themselves have been tested against experimental results. Experimental energy barriers and enthalpies for ring inversion, nitrogen inversion and dehydrochlorination reactions in N-chloropiperidine have been accurately reproduced when solvent effects have been included. It was also found that the combined use of continuum solvation models (e.g. CPCM) and explicit consideration of a single water molecule is sufficient to properly describe the water-assisted rearrangement of N-chlorinated compounds in basic media. In the case of N-chloro-4-(4-fluorophenyl)-3-(hydroxymethyl)piperidine, which represents the chlorinated metabolite of the antidepressant paroxetine, several different reactions (intramolecular addition, substitution, and elimination reactions) have been investigated. Transition state structures for these processes have been located together with minimum energy structures of conceivable products. Imine 4A is predicted to be the most stable reaction product, closely followed by imine 4B and oxazinane 8, while formation of isoxazolidine 7 is much less favourable. Calculated reaction barriers in aqueous solution are quite similar for all four processes, the lowest barrier being predicted for the formation of imine 4A.

  17. Effects of an Environmentally Relevant Phthalate Mixture on Cultured Mouse Antral Follicles.

    PubMed

    Zhou, Changqing; Flaws, Jodi A

    2017-03-01

    Phthalates are used in building materials, medical devices, and personal care products. Most studies on phthalates have focused on single phthalates, but it is important to study mixtures of phthalates because humans are exposed to such mixtures daily. We tested the hypothesis that phthalate mixture exposure decreases antral follicle growth, compromises steroidogenic capacity, and induces atresia. Antral follicles from adult CD-1 mice were cultured with vehicle control or phthalate mixture (1-500 µg/ml) for 96 h. The mixture was made of 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% diisononyl phthalate, 8% diisobutyl phthalate, and 5% benzylbutyl phthalate. During culture, antral follicle diameters were measured every 24 h to monitor growth. After culture, media were subjected to measurements of sex steroid hormones and follicles were subjected to evaluation of gene expression and atresia. The phthalate mixture (100 and 500 µg/ml) decreased antral follicle growth starting at 24 h compared to controls. The mixture at 10, 100, and 500 µg/ml also decreased androstenedione, testosterone, estrone, and estradiol levels compared to control. The mixture (10, 100, and 500 µg/ml) reduced atresia rating, but it induced more oocyte fragmentation compared to control. The phthalate mixture at different doses adversely affected cell cycle regulators, antioxidant enzymes, apoptotic factors, steroidogenic enzymes, and receptors. Collectively, these data indicate that exposure to an environmentally relevant phthalate mixture reduces antral follicle growth, induces oocyte fragmentation, and decreases hormone production by adversely affecting the expression of cell cycle regulators, apoptotic factors, steroidogenic enzymes, and receptors. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Enabling multi-level relevance feedback on PubMed by integrating rank learning into DBMS

    PubMed Central

    2010-01-01

    Background Finding relevant articles from PubMed is challenging because it is hard to express the user's specific intention in the given query interface, and a keyword query typically retrieves a large number of results. Researchers have applied machine learning techniques to find relevant articles by ranking the articles according to the learned relevance function. However, the process of learning and ranking is usually done offline without integrated with the keyword queries, and the users have to provide a large amount of training documents to get a reasonable learning accuracy. This paper proposes a novel multi-level relevance feedback system for PubMed, called RefMed, which supports both ad-hoc keyword queries and a multi-level relevance feedback in real time on PubMed. Results RefMed supports a multi-level relevance feedback by using the RankSVM as the learning method, and thus it achieves higher accuracy with less feedback. RefMed "tightly" integrates the RankSVM into RDBMS to support both keyword queries and the multi-level relevance feedback in real time; the tight coupling of the RankSVM and DBMS substantially improves the processing time. An efficient parameter selection method for the RankSVM is also proposed, which tunes the RankSVM parameter without performing validation. Thereby, RefMed achieves a high learning accuracy in real time without performing a validation process. RefMed is accessible at http://dm.postech.ac.kr/refmed. Conclusions RefMed is the first multi-level relevance feedback system for PubMed, which achieves a high accuracy with less feedback. It effectively learns an accurate relevance function from the user’s feedback and efficiently processes the function to return relevant articles in real time. PMID:20406504

  19. Chronic ZnO-NPs exposure at environmentally relevant concentrations results in metabolic and locomotive toxicities in Caenorhabditis elegans.

    PubMed

    Huang, Chi-Wei; Li, Shang-Wei; Hsiu-Chuan Liao, Vivian

    2017-01-01

    ZnO nanoparticles (ZnO-NPs) are emerging contaminants that raise the concerns of potential risk in the aquatic environment. It has been estimated that the environmental ZnO-NPs concentration is 76 μg/l in the aquatic environment. Our aim was to determine the aquatic toxicity of ZnO-NPs with chronic exposure at environmentally relevant concentrations using the nematode Caenorhabditis elegans. Two simulated environmentally relevant mediums-moderately hard reconstituted water (EPA water) and simulated soil pore water (SSPW)-were used to represent surface water and pore water in sediment, respectively. The results showed that the ZnO-NPs in EPA water has a much smaller hydrodynamic diameter than that in SSPW. Although the ionic release of Zn ions increased time-dependently in both mediums, the Zn ions concentrations in EPA water increased two-fold more than that in SSPW at 48 h and 72 h. The ZnO-NPs did not induce growth defects or decrease head thrashes in C. elegans in either media. However, chronic exposure to ZnO-NPs caused a significant reduction in C. elegans body bends in EPA water even with a relatively low concentration (0.05 μg/l); similar results were not observed in SSPW. Moreover, at the same concentrations (50 and 500 μg/l), body bends in C. elegans were reduced more severely in ZnO-NPs than in ZnCl2 in EPA water. The ATP levels were consistently and significantly decreased, and ROS was induced after ZnO-NPs exposure (50 and 500 μg/l) in EPA water. Our results provide evidences that chronic exposure to ZnO-NPs under environmentally relevant concentrations causes metabolic and locomotive toxicities implicating the potential ecotoxicity of ZnO-NPs at low concentrations in aquatic environments.

  20. An integrated proteomic and metabolomic study on the chronic effects of mercury in Suaeda salsa under an environmentally relevant salinity.

    PubMed

    Liu, Xiaoli; Wu, Huifeng; Ji, Chenglong; Wei, Lei; Zhao, Jianmin; Yu, Junbao

    2013-01-01

    As an environmental contaminant, mercury is of great concern due to its high risk to environmental and human health. The halophyte Suaeda salsa is the dominant plant in the intertidal zones of the Yellow River Delta (YRD) where has been contaminated by mercury in some places. This study aimed at evaluating the chronic effects of mercury (Hg(2+), 20 µg L(-1)) and the influence of an environmentally relevant salinity (NaCl, 500 mM) on mercury-induced effects in S. salsa. A total of 43 protein spots with significant changes were identified in response to Hg(2+), salinity and combined Hg(2+) and salinity. These proteins can be categorized into diverse functional classes, related to metabolic processes, photosynthesis, stress response, protein fate, energy metabolism, signaling pathways and immunosuppression. Metabolic responses demonstrated that Hg(2+) could disturb protein and energy metabolisms in S. salsa co-exposed with or without salinity. In addition, both antagonistic and synergistic effects between Hg(2+) and salinity were confirmed by differential levels of proteins (magnesium-chelatase and ribulose-l,5-bisphosphate carboxylase/oxygenase) and metabolites (valine, malonate, asparagine, glycine, fructose and glucose) in S. salsa. These findings suggest that a combination of proteomics and metabolomics can provide insightful information of environmental contaminant-induced effects in plants at molecular levels.

  1. An Integrated Proteomic and Metabolomic Study on the Chronic Effects of Mercury in Suaeda salsa under an Environmentally Relevant Salinity

    PubMed Central

    Liu, Xiaoli; Wu, Huifeng; Ji, Chenglong; Wei, Lei; Zhao, Jianmin; Yu, Junbao

    2013-01-01

    As an environmental contaminant, mercury is of great concern due to its high risk to environmental and human health. The halophyte Suaeda salsa is the dominant plant in the intertidal zones of the Yellow River Delta (YRD) where has been contaminated by mercury in some places. This study aimed at evaluating the chronic effects of mercury (Hg2+, 20 µg L−1) and the influence of an environmentally relevant salinity (NaCl, 500 mM) on mercury-induced effects in S. salsa. A total of 43 protein spots with significant changes were identified in response to Hg2+, salinity and combined Hg2+ and salinity. These proteins can be categorized into diverse functional classes, related to metabolic processes, photosynthesis, stress response, protein fate, energy metabolism, signaling pathways and immunosuppression. Metabolic responses demonstrated that Hg2+ could disturb protein and energy metabolisms in S. salsa co-exposed with or without salinity. In addition, both antagonistic and synergistic effects between Hg2+ and salinity were confirmed by differential levels of proteins (magnesium-chelatase and ribulose-l,5-bisphosphate carboxylase/oxygenase) and metabolites (valine, malonate, asparagine, glycine, fructose and glucose) in S. salsa. These findings suggest that a combination of proteomics and metabolomics can provide insightful information of environmental contaminant-induced effects in plants at molecular levels. PMID:23696864

  2. Manipulating Sensory and Phytochemical Profiles of Greenhouse Tomatoes Using Environmentally Relevant Doses of Ultraviolet Radiation.

    PubMed

    Dzakovich, Michael P; Ferruzzi, Mario G; Mitchell, Cary A

    2016-09-14

    Fruits harvested from off-season, greenhouse-grown tomato plants have a poor reputation compared to their in-season, garden-grown counterparts. Presently, there is a gap in knowledge with regard to the role of UV-B radiation (280-315 nm) in determining greenhouse tomato quality. Knowing that UV-B is a powerful elicitor of secondary metabolism and not transmitted through greenhouse glass and some greenhouse plastics, we tested the hypothesis that supplemental UV-B radiation in the greenhouse will impart quality attributes typically associated with garden-grown tomatoes. Environmentally relevant doses of supplemental UV-B radiation did not strongly affect antioxidant compounds of fruits, although the flavonol quercetin-3-O-rutinoside (rutin) significantly increased in response to UV-B. Physicochemical metrics of fruit quality attributes and consumer sensory panels were used to determine if any such differences altered consumer perception of tomato quality. Supplemental UV-A radiation (315-400 nm) pre-harvest treatments enhanced sensory perception of aroma, acidity, and overall approval, suggesting a compelling opportunity to environmentally enhance the flavor of greenhouse-grown tomatoes. The expression of the genes COP1 and HY5 were indicative of adaptation to UV radiation, which explains the lack of marked effects reported in these studies. To our knowledge, these studies represent the first reported use of environmentally relevant doses of UV radiation throughout the reproductive portion of the tomato plant life cycle to positively enhance the sensory and chemical properties of fruits.

  3. Oil Recovery from Water under Environmentally Relevant Conditions Using Magnetic Nanoparticles.

    PubMed

    Mirshahghassemi, Seyyedali; Lead, Jamie R

    2015-10-06

    Large oil spills and oily wastewater discharges from ships and industrial activities can have serious impacts on the environment with potentially major economic impacts. Current oil remediation techniques are inefficient and may have deleterious environmental consequences. However, nanotechnology offers a new route to potentially remediate oil pollution. In this study, a cheap and facile hydrothermal method was developed to synthesize polyvinylpyrrolidone-coated magnetite nanoparticles to separate a reference MC252 oil from oil-water mixture under environmentally relevant conditions. Fluorescence and Proton nuclear magnetic resonance spectroscopy results showed near 100% oil removal from oil-water mixture in the ultrapure water under optimum condition. Based on gas chromatography-mass spectrometry data, approximately 100% of lower molecular mass alkanes (C9-C21) were removed within 10 min of magnetic separation and by increasing the separation time to 40 min, greater than 67% of C22-25 alkanes were removed. Moreover, nanoparticles removed near 100% oil from synthetic seawater solutions in the presence and absence of fulvic acid showing excellent oil removal capacity of the nanoparticles under different conditions. Results show that these nanoparticles can be utilized to remove oil over a short time with a high removal efficiency under environmentally relevant conditions.

  4. An aggregate analysis of personal care products in the environment: Identifying the distribution of environmentally-relevant concentrations.

    PubMed

    Hopkins, Zachary R; Blaney, Lee

    2016-01-01

    Over the past 3-4 decades, per capita consumption of personal care products (PCPs) has steadily risen, resulting in increased discharge of the active and inactive ingredients present in these products into wastewater collection systems. PCPs comprise a long list of compounds employed in toothpaste, sunscreen, lotions, soaps, body washes, and insect repellants, among others. While comprehensive toxicological studies are not yet available, an increasing body of literature has shown that PCPs of all classes can impact aquatic wildlife, bacteria, and/or mammalian cells at low concentrations. Ongoing research efforts have identified PCPs in a variety of environmental compartments, including raw wastewater, wastewater effluent, surface water, wastewater solids, sediment, groundwater, and drinking water. Here, an aggregate analysis of over 5000 reported detections was conducted to better understand the distribution of environmentally-relevant PCP concentrations in, and between, these compartments. The distributions were used to identify whether aggregated environmentally-relevant concentration ranges intersected with available toxicity data. For raw wastewater, wastewater effluent, and surface water, a clear overlap was present between the 25th-75th percentiles and identified toxicity levels. This analysis suggests that improved wastewater treatment of antimicrobials, UV filters, and polycyclic musks is required to prevent negative impacts on aquatic species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Lessons from the Navajo: Assistance with Environmental Data Collection Ensures Cultural Humility and Data Relevance

    PubMed Central

    deLemos, Jamie; Rock, Tommy; Brugge, Doug; Slagowski, Naomi; Manning, Thomas; Lewis, Johnnye

    2008-01-01

    Background The Navajo Nation suffers from a legacy of environmental pollution from historical uranium mining activities, resulting in adverse public health outcomes and continuous exposure. Objective Partner with a Navajo graduate student and community members in a field campaign to characterize the spatial distribution and geochemistry of uranium for a multipathway uranium exposure assessment under development by the Dine Network for Environmental Health (DiNEH) project. Methods Attend community meetings, acquire Navajo language skills, and integrate local knowledge into sampling approach of sediment, water, and vegetation. Results Navajo participation (1) helped to foster trust in research efforts during community interactions, (2) taught aspects of Navajo culture and language to maintain positive and respectful relations, and (3) conveyed information on Navajo culture that would impact sampling strategies. Conclusions Community engagement helps to sustain equitable partnerships and aids in culturally appropriate, relevant data collection. PMID:19655034

  6. The effect of environmentally relevant conditions on PVP stabilised gold nanoparticles.

    PubMed

    Hitchman, Adam; Smith, Gregory H Sambrook; Ju-Nam, Yon; Sterling, Mark; Lead, Jamie R

    2013-01-01

    Nanoparticles are a major product from the nanotechnology industry and have been shown to have a potentially large environmental exposure and hazard. In this study, sterically stabilised polyvinyl pyrrolidone (PVP) 7 nm gold nanoparticles (NPs) were produced and characterised as prepared by surface plasmon resonance (SPR), size and aggregation, morphology and surface charge. Changes in these properties with changes in environmentally relevant conditions (pH, ionic strength, Ca concentration and fulvic acid presence) were quantified. These sterically stabilised NPs showed no aggregation with changes in pH or inorganic ions, even under high (0.1 M) Ca concentrations. In addition, the presence of fulvic acid resulted in no observable changes in SPR, size, aggregation or surface chemistry, suggesting limited interaction between the PVP stabilised nanoparticles and fulvic acid. Due to the lack of aggregation and interaction, these NPs are expected to be highly mobile and potentially bioavailable in the environment.

  7. Supramolecular Chemistry of Selective Anion Recognition for Anions of Environmental Relevance

    SciTech Connect

    Bowman-James, K.; Wilson, G.; Moyer, B. A.

    2004-12-11

    This project involves the design and synthesis of receptors for oxoanions of environmental importance, including emphasis on high level and low activity waste. Target anions have included primarily oxoanions and a study of the basic concepts behind selective binding of target anions. A primary target has been sulfate because of its deleterious influence on the vitrification of tank wastes

  8. Prenatal exposure to an environmentally relevant phthalate mixture disrupts reproduction in F1 female mice.

    PubMed

    Zhou, Changqing; Gao, Liying; Flaws, Jodi A

    2017-03-01

    Phthalates are used in a large variety of products, such as building materials, medical devices, and personal care products. Most previous studies on the toxicity of phthalates have focused on single phthalates, but it is also important to study the effects of phthalate mixtures because humans are exposed to phthalate mixtures. Thus, we tested the hypothesis that prenatal exposure to an environmentally relevant phthalate mixture adversely affects female reproduction in mice. To test this hypothesis, pregnant CD-1 dams were orally dosed with vehicle (tocopherol-stripped corn oil) or a phthalate mixture (20 and 200μg/kg/day, 200 and 500mg/kg/day) daily from gestational day 10 to birth. The mixture was based on the composition of phthalates detected in urine samples from pregnant women in Illinois. The mixture included 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% diisononyl phthalate, 8% diisobutyl phthalate, and 5% benzylbutyl phthalate. Female mice born to the exposed dams were subjected to tissue collections and fertility tests at different ages. Our results indicate that prenatal exposure to the phthalate mixture significantly increased uterine weight and decreased anogenital distance on postnatal days 8 and 60, induced cystic ovaries at 13months, disrupted estrous cyclicity, reduced fertility-related indices, and caused some breeding complications at 3, 6, and 9months of age. Collectively, our data suggest that prenatal exposure to an environmentally relevant phthalate mixture disrupts aspects of female reproduction in mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Marble wastes and pig slurry improve the environmental and plant-relevant properties of mine tailings.

    PubMed

    Kabas, S; Faz, A; Acosta, J A; Arocena, J M; Zornoza, R; Martínez-Martínez, S; Carmona, D M

    2014-02-01

    Poor soil fertility is often the biggest challenge to the establishment of vegetation in mine wastes deposits. We conducted field trials in the El Gorguel and El Lirio sites in SE Spain, two representative tailing ponds of similar properties except for pH, to understand the environmental and plant-relevant benefits of marble waste (MW) and pig slurry (PS) applications to mine tailings. Low pH (5.4) tailings (El Lirio) exhibit reduction of up to fourfold in bio-availability of metals as shown by the DTPA-Zn, Pb, water-soluble Zn, Pb and up to 3× for water-soluble Cd. Tailings in El Gorguel have high pH (7.4) and did not exhibit significant trends in the reductions of water-extractable Zn, Pb, Cd and Cu. Improvements to the edaphic (plant-relevant) properties of tailings after the amendments are not as sensitive to pH compared to the environmental characteristics. The two sites had increases in aggregate stability, organic matter (total N and organic C) although total N is higher in the El Gorguel (up to 212 μg N kg(-1)) than the El Lirio (up to 26 μg N kg(-1)). However, cation exchange capacities are similar in both sites at 15.2 cmol(+) kg(-1). We conclude that the characteristics, especially pH, of tailing materials significantly influence the fate of metals but not improvements to plant-relevant properties such as cation exchange capacity and aggregate stability 1 year after the application of MW and PS amendments.

  10. Improving landscape-level environmental impact evaluations.

    SciTech Connect

    Walston, L.J.; LaGory, K.E.; Vinikour, W.; Van Lonkhuyzen, R.L.; Cantwell, B.

    2012-04-01

    New spatial data and advancements in GIS tools allow much more comprehensive and quantitative analyses of the large datasets required when making programmatic evaluations of the ecological effects of proposed activities that cover a large area or region. Understanding the environmental impacts of proposed human developments is critical to making appropriate siting decisions and designing mitigation strategies to reduce impacts on important resources. Impact analyses conducted under the National Environmental Policy Act (NEPA) in Environmental Impact Statements (EISs) or Environmental Assessments (EAs) are intended to determine the resource-specific impacts of proposed activities of federal agencies and their alternatives using the best available information. Impacts to ecological resources are often a primary focus of these analyses. Information used in NEPA analyses include some measure of the known or probable presence of plants and wildlife in the project area, with special emphasis placed on threatened, endangered, and other special-status species. Site-specific information pertaining to ecological resources is usually easier to obtain for small-scale activities such as a local facility, road, or transmission upgrade project, where the ability to conduct fieldwork is more often feasible. However, site-specific data is more difficult-and sometimes impossible-to obtain for proposed activities that could affect a large area or region. These types of analyses often are considered in programmatic NEPA documents, in which a federal agency evaluates the implementation of a broad program or plan. Under these programmatic evaluations, the exact location and size of developments are often not known. Because obtaining quantitative information for ecological resources at such large spatial scales is difficult, programmatic impact evaluations typically rely on sketchy or partial information such as recorded species occurrences, species ranges, and general habitat

  11. LFERs for soil organic carbon-water distribution coefficients (Koc) at environmentally relevant sorbate concentrations.

    PubMed

    Endo, Satoshi; Grathwohl, Peter; Haderlein, Stefan B; Schmidt, Torsten C

    2009-05-01

    Organic carbon-water distribution coefficients, Koc, for organic compounds at environmentally relevant, low sorbate concentrations may substantially differ from those at higher concentrations due to nonlinear sorption to soil organic matter. However, prediction methods for Koc such as linear free energy relationships (LFERs) are currently only available for high sorbate concentrations (i.e., near solubility limits), reflecting the lack of a set of consistent experimental data in an environmentally more relevant concentration range (i.e., orders of magnitude lower than solubilities). In this study, we determined Koc for two model sorbents of soil organic matter, peat and lignite, at sorbate concentrations of 4.3 and 19 mg/kg-organic-carbon, respectively, in batch suspensions. The measured Koc values for organic sorbates (51 for peat, 58 for lignite) of varying sizes and polarities were modeled successfully with polyparameter linear free energy relationships (PP-LFERs). The resulting PP-LFER for peat was significantly different from the PP-LFERs in the literature determined at near aqueous solubility limits of sorbates. The literature PP-LFERs were found to underestimate the measured Koc values for peat at the low concentration by up to 1 order of magnitude. The extent of underestimation highly depends on the sorbate properties and can be explained by differing sorption nonlinearities of the sorbates as predicted by a reported empirical relationship between the nonlinearity in peat and the sorbate dipolarity/polarizability parameter S. Lignite appearsto be a stronger sorbent toward many sorbates than typical soil organic matter irrespective of the concentration range and thus may not be representative for organic matter with regard to the magnitude of Koc. The present study offers the first PP-LFER equation for log Koc in soil organic matter at typical environmental sorbate concentrations.

  12. CHANGES IN GENE EXPRESSION PROFILE FOLLOWING SHORT-TERM EXPOSURE TO AN ENVIRONMENTALLY RELEVANT MIXTURE OF PHAHS

    EPA Science Inventory

    Changes in gene expression profile following short-term exposure to an environmentally relevant mixture of PHAHs
    Polyhalogenated aromatic hydrocarbons (PHAH) including, polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDS) and polychlorinated dibenzofurans...

  13. Human health and the environment: Predicting plasma protein binding and metabolic clearance rates of environmentally relevant chemicals.

    EPA Science Inventory

    In silico methods provide a rapid, inexpensive means of screening a wide array of environmentally relevant pollutants, pesticides, fungicides and consumer products for further toxicity testing. Physiologically based pharmacokinetic (PBPK) models bridge the gap between in vitro as...

  14. CHANGES IN GENE EXPRESSION PROFILE FOLLOWING SHORT-TERM EXPOSURE TO AN ENVIRONMENTALLY RELEVANT MIXTURE OF PHAHS

    EPA Science Inventory

    Changes in gene expression profile following short-term exposure to an environmentally relevant mixture of PHAHs
    Polyhalogenated aromatic hydrocarbons (PHAH) including, polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDS) and polychlorinated dibenzofurans...

  15. Human health and the environment: Predicting plasma protein binding and metabolic clearance rates of environmentally relevant chemicals.

    EPA Science Inventory

    In silico methods provide a rapid, inexpensive means of screening a wide array of environmentally relevant pollutants, pesticides, fungicides and consumer products for further toxicity testing. Physiologically based pharmacokinetic (PBPK) models bridge the gap between in vitro as...

  16. Mapping Environmental Inequalities Relevant for Health for Informing Urban Planning Interventions—A Case Study in the City of Dortmund, Germany

    PubMed Central

    Flacke, Johannes; Schüle, Steffen Andreas; Köckler, Heike; Bolte, Gabriele

    2016-01-01

    Spatial differences in urban environmental conditions contribute to health inequalities within cities. The purpose of the paper is to map environmental inequalities relevant for health in the City of Dortmund, Germany, in order to identify needs for planning interventions. We develop suitable indicators for mapping socioeconomically-driven environmental inequalities at the neighborhood level based on published scientific evidence and inputs from local stakeholders. Relationships between socioeconomic and environmental indicators at the level of 170 neighborhoods were analyzed continuously with Spearman rank correlation coefficients and categorically applying chi-squared tests. Reclassified socioeconomic and environmental indicators were then mapped at the neighborhood level in order to determine multiple environmental burdens and hotspots of environmental inequalities related to health. Results show that the majority of environmental indicators correlate significantly, leading to multiple environmental burdens in specific neighborhoods. Some of these neighborhoods also have significantly larger proportions of inhabitants of a lower socioeconomic position indicating hotspots of environmental inequalities. Suitable planning interventions mainly comprise transport planning and green space management. In the conclusions, we discuss how the analysis can be used to improve state of the art planning instruments, such as clean air action planning or noise reduction planning towards the consideration of the vulnerability of the population. PMID:27420090

  17. Mapping Environmental Inequalities Relevant for Health for Informing Urban Planning Interventions-A Case Study in the City of Dortmund, Germany.

    PubMed

    Flacke, Johannes; Schüle, Steffen Andreas; Köckler, Heike; Bolte, Gabriele

    2016-07-13

    Spatial differences in urban environmental conditions contribute to health inequalities within cities. The purpose of the paper is to map environmental inequalities relevant for health in the City of Dortmund, Germany, in order to identify needs for planning interventions. We develop suitable indicators for mapping socioeconomically-driven environmental inequalities at the neighborhood level based on published scientific evidence and inputs from local stakeholders. Relationships between socioeconomic and environmental indicators at the level of 170 neighborhoods were analyzed continuously with Spearman rank correlation coefficients and categorically applying chi-squared tests. Reclassified socioeconomic and environmental indicators were then mapped at the neighborhood level in order to determine multiple environmental burdens and hotspots of environmental inequalities related to health. Results show that the majority of environmental indicators correlate significantly, leading to multiple environmental burdens in specific neighborhoods. Some of these neighborhoods also have significantly larger proportions of inhabitants of a lower socioeconomic position indicating hotspots of environmental inequalities. Suitable planning interventions mainly comprise transport planning and green space management. In the conclusions, we discuss how the analysis can be used to improve state of the art planning instruments, such as clean air action planning or noise reduction planning towards the consideration of the vulnerability of the population.

  18. Heteroaggregation of titanium dioxide nanoparticles with model natural colloids under environmentally relevant conditions.

    PubMed

    Praetorius, Antonia; Labille, Jérôme; Scheringer, Martin; Thill, Antoine; Hungerbühler, Konrad; Bottero, Jean-Yves

    2014-09-16

    The heteroaggregation of engineered nanoparticles (ENPs) with natural colloids (NCs), which are ubiquitous in natural surface waters, is a crucial process affecting the environmental transport and fate of ENPs. Attachment efficiencies for heteroaggregation, α hetero, are required as input parameters in environmental fate models to predict ENP concentrations and contribute to ENP risk assessment. Here, we present a novel method for determining α hetero values by using a combination of laser diffraction measurements and aggregation modeling based on the Smoluchowski equation. Titanium dioxide nanoparticles (TiO2 NPs, 15 nm) were used to demonstrate this new approach together with larger silicon dioxide particles (SiO2, 0.5 μm) representing NCs. Heteroaggregation experiments were performed at different environmentally relevant solution conditions. At pH 5 the TiO2 NPs and the SiO2 particles are of opposite charge, resulting in α hetero values close to 1. At pH 8, where all particles are negatively charged, α hetero was strongly affected by the solution conditions, with α hetero ranging from <0.001 at low ionic strength to 1 at conditions with high NaCl or CaCl2 concentrations. The presence of humic acid stabilized the system against heteroaggregation.

  19. Toxicological effects of environmentally relevant lead and zinc in halophyte Suaeda salsa by NMR-based metabolomics.

    PubMed

    Wu, Huifeng; Liu, Xiaoli; Zhao, Jianmin; Yu, Junbao; Pang, Qiuying; Feng, Jianghua

    2012-11-01

    Lead (Pb) and zinc (Zn) are two typical metal contaminants with high levels in both seawater and sediment in the intertidal zones of the Bohai Sea. Suaeda salsa is the pioneer halophyte plant in the intertidal zones of the Bohai Sea. In the present work, the short (1 week) and long term (1 month) toxicological effects of environmentally relevant concentrations of Pb and Zn were characterized in S. salsa using NMR-based metabolomics combined with antioxidant enzyme activities. After metal exposure for 1 week, no significant metabolic responses were detected in root tissues of S. salsa. The significant metabolic responses included the increase of isocaproate, glucose and fructose, and decrease of malate, citrate and sucrose in root tissues of S. salsa exposed to Pb for 1 month. The increased phosphocholine and betaine, and decreased choline were uniquely found in Zn-exposed samples. The metabolic changes including decreased malate, citrate and sucrose were detected in both Pb and Zn-exposed groups. These metabolic biomarkers revealed that both Pb and Zn exposures could induce osmotic stress and disturbances in energy metabolism in S. salsa after exposures for 1 month. Overall, this work demonstrates that metabolomics can be used to elucidate toxicological effects of environmentally relevant metal contaminants using halophyte S. salsa as the bioindicator.

  20. Physiological responses and gene expression changes in the western mosquitofish (Gambusia affinis) exposed to progesterone at environmentally relevant concentrations.

    PubMed

    Hou, Liping; Xu, Hongyan; Ying, Guangguo; Yang, Yang; Shu, Hu; Zhao, Jianliang; Cheng, Xuemei

    2017-09-14

    Progesterone (P4) is a natural and synthetic steroid, widely distributed in the aquatic environments. It can lead to adverse effects on the endocrine system in aquatic organisms. This study investigated the toxicological effects of exposure to environmentally relevant concentrations (4, 44, and 410ng/L) of progesterone for 42 d on adult female mosquitofish, Gambusia affinis. We performed morphological and histological analyses on gonads, anal fins, liver, and gills after the exposure of mosquito fish to P4. The expression levels of genes (vtg, er, and ar isoforms) related to fish reproduction and detoxification (cyp1a) in the liver were quantified by quantitative real-time polymerase chain reaction. The results showed that the progesterone exposure induced slight masculinization in female mosquitofish, influenced the oocyte maturation as revealed by histology of the ovaries, and caused severe damages to the liver and gills of adult female mosquitofish. It also suppressed the mRNAs expression of vtg, er, cyp1a, and significantly enhanced the expression of ar mRNA in the liver. This study reveals the molecular and physiological effects of progesterone at environmentally relevant concentrations, which might further be translated to alterations in the reproduction of mosquitofish. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. BEST: Bilingual environmental science training: Kindergarten level

    SciTech Connect

    1996-03-01

    This booklet is one of a series of bilingual guides to environmental-science learning activities for students to do at home. Lesson objectives, materials required, procedure, vocabulary, and subjects integrated into the lesson are described in English for each lesson. A bilingual glossary, alphabetized by English entries, with Spanish equivalents in both English and Spanish, follows the lesson descriptions, and is itself followed by a bibliography of English-language references. This booklet includes descriptions of six lessons covering the senses of touch and sight, the sense of smell, how to distinguish living and non-living things, cell structures, the skeletal system, and the significance of food groups. 8 figs.

  2. Linking feeding inhibition with reproductive impairment in Gammarus confirms the ecological relevance of feeding assays in environmental monitoring.

    PubMed

    Coulaud, Romain; Geffard, Olivier; Vigneron, Amandine; Quéau, Hervé; François, Adeline; Chaumot, Arnaud

    2015-05-01

    The in situ feeding bioassay in Gammarus fossarum is recognized as a reliable tool for monitoring the toxicity of freshwater contamination. However, whether recorded feeding inhibitions can potentially provoke population-level adverse outcomes remains an open question. In the present study, the authors present an experimental study in G. fossarum, which contributes to the quantitative description of the links between feeding inhibitions and impacts on female reproductive performance. The authors studied the impacts of food deprivation on reproductive endpoints (i.e., fecundity, fertility, molt cycle) during 2 successive molting cycles. Among the main results, the authors found that food deprivation triggered a slowdown of the molting process and a reduction in fertility but no alteration to embryonic development. These reproductive impairments appeared for feeding inhibition values usually recorded in monitoring programs of environmental pollution. Using a population model translating Gammarus life-history, the authors predicted that the observed reproductive alterations predict a strong degradation of population dynamics. The present study underlines the importance of feeding inhibition in population-level risk assessment and discusses how establishing upscaling schemes based on quantitative mechanistic links between impacts at different levels of biological organization can be applied in environmental monitoring to propose an ecotoxicological assessment of water quality, which would be sensitive, specific, and ecologically relevant. © 2015 SETAC.

  3. The design of an environmentally relevant mixture of persistent organic pollutants for use in in vivo and in vitro studies.

    PubMed

    Berntsen, Hanne Friis; Berg, Vidar; Thomsen, Cathrine; Ropstad, Erik; Zimmer, Karin Elisabeth

    2017-08-30

    Amongst the substances listed as persistent organic pollutants (POP) under the Stockholm Convention on Persistent Organic Pollutants (SCPOP) are chlorinated, brominated, and fluorinated compounds. Most experimental studies investigating effects of POP employ single compounds. Studies focusing on effects of POP mixtures are limited, and often conducted using extracts from collected specimens. Confounding effects of unmeasured substances in such extracts may bias the estimates of presumed causal relationships being examined. The aim of this investigation was to design a model of an environmentally relevant mixture of POP for use in experimental studies, containing 29 different chlorinated, brominated, and perfluorinated compounds. POP listed under the SCPOP and reported to occur at the highest levels in Scandinavian food, blood, or breast milk prior to 2012 were selected, and two different mixtures representing varying exposure scenarios constructed. The in vivo mixture contained POP concentrations based upon human estimated daily intakes (EDIs), whereas the in vitro mixture was based upon levels in human blood. In addition to total in vitro mixture, 6 submixtures containing the same concentration of chlorinated + brominated, chlorinated + perfluorinated, brominated + perfluorinated, or chlorinated, brominated or perfluorinated compounds only were constructed. Using submixtures enables investigating the effect of adding or removing one or more chemical groups. Concentrations of compounds included in feed and in vitro mixtures were verified by chemical analysis. It is suggested that this method may be utilized to construct realistic mixtures of environmental contaminants for toxicity studies based upon the relative levels of POP to which individuals are exposed.

  4. Systematic testing of Gaussian and complete basis set methods with dispersion corrections for environmentally relevant clusters

    NASA Astrophysics Data System (ADS)

    Lemke, Kono H.

    2014-11-01

    Results are presented demonstrating the ability of CBS-x and Gn theory to predict energies for non-covalently bound complexes, both uncorrected and upon implementation of dispersion-sensitive DFT. CBS-QCI/APNO performs best among uncorrected methods (MUE 0.88 kcal mol-1), while G4 (MUE 1.05 kcal mol-1) and CBS-QB3 (MUE 1.13 kcal mol-1) provide energies close to that of CBS-QCI/APNO, but at a reduced cost. Inclusion of B2PLYP-D and B97-D as well as M0N-2X type functionals into G4 and CBS-QB3 results in improved binding energies. From a comparison with CCSD(T)/CBS results, M05-2X/CBS-QB3 structures and binding energies provide a cost-effective and accurate description of environmentally relevant non-covalent interactions.

  5. Campylobacter species in animal, food, and environmental sources, and relevant testing programs in Canada.

    PubMed

    Huang, Hongsheng; Brooks, Brian W; Lowman, Ruff; Carrillo, Catherine D

    2015-10-01

    Campylobacter species, particularly thermophilic campylobacters, have emerged as a leading cause of human foodborne gastroenteritis worldwide, with Campylobacter jejuni, Campylobacter coli, and Campylobacter lari responsible for the majority of human infections. Although most cases of campylobacteriosis are self-limiting, campylobacteriosis represents a significant public health burden. Human illness caused by infection with campylobacters has been reported across Canada since the early 1970s. Many studies have shown that dietary sources, including food, particularly raw poultry and other meat products, raw milk, and contaminated water, have contributed to outbreaks of campylobacteriosis in Canada. Campylobacter spp. have also been detected in a wide range of animal and environmental sources, including water, in Canada. The purpose of this article is to review (i) the prevalence of Campylobacter spp. in animals, food, and the environment, and (ii) the relevant testing programs in Canada with a focus on the potential links between campylobacters and human health in Canada.

  6. Micro hot plate-based sensor array system for the detection of environmentally relevant gases.

    PubMed

    Graf, M; Frey, U; Taschini, S; Hierlemann, A

    2006-10-01

    A monolithic stand-alone gas sensor system is presented, which includes on a single chip an array of three metal oxide-coated micro hot plates with integrated MOS-transistor heaters, as well as a specifically designed digital system architecture. An octagonal-shaped micro hot plate design with MOS-transistor heaters has been adopted for the three gas sensors. The integrated circuitry includes a programmable digital temperature regulation, digital sensor readout units, and a standard serial interface. The programmable digital temperature controllers enable individual regulation of the micro hot plate temperatures in constant or dynamic mode. Nanocrystalline tin oxide thick films with different Pd dopings (undoped, 0.2 and 3 wt %) were used. Gas test measurements for environmentally relevant gases were carried out and evidenced detection limits of less than 1 ppm for carbon monoxide, or 100 ppm for methane, both at 40% relative humidity. Temperature modulation techniques were successfully applied for improved analyte discrimination.

  7. Clobetasol propionate causes immunosuppression in zebrafish (Danio rerio) at environmentally relevant concentrations.

    PubMed

    Hidasi, Anita O; Groh, Ksenia J; Suter, Marc J-F; Schirmer, Kristin

    2017-04-01

    Synthetic glucocorticoids (GCs) are potential endocrine disrupting compounds that have been detected in the aquatic environment around the world in the low ng/L (nanomolar) range. GCs are used as immunosuppressants in medicine. It is of high interest whether clobetasol propionate (CP), a highly potent GC, suppresses the inflammatory response in fish after exposure to environmentally relevant concentrations. Bacterial lipopolysaccharide (LPS) challenge was used to induce inflammation and thus mimic pathogen infection. Zebrafish embryos were exposed to ≤1000nM CP from ~1h post fertilization (hpf) to 96 hpf, and CP uptake, survival after LPS challenge, and expression of inflammation-related genes were examined. Our initial experiments were carried out using 0.001% DMSO as a solvent vehicle, but we observed that DMSO interfered with the LPS challenge assay, and thus masked the effects of CP. Therefore, DMSO was not used in the subsequent experiments. The internal CP concentration was quantifiable after exposure to ≥10nM CP for 96h. The bioconcentration factor (BCF) of CP was determined to be between 16 and 33 in zebrafish embryos. CP-exposed embryos showed a significantly higher survival rate in the LPS challenge assay after exposure to ≥0.1nM in a dose dependent manner. This effect is an indication of immunosuppression. Furthermore, the regulation pattern of several genes related to LPS challenge in mammals supported our results, providing evidence that LPS-mediated inflammatory pathways are conserved from mammals to teleost fish. Anxa1b, a GC-action related anti-inflammatory gene, was significantly down-regulated after exposure to ≥0.05nM CP. Our results show for the first time that synthetic GCs can suppress the innate immune system of fish at environmentally relevant concentrations. This may reduce the chances of fish to survive in the environment, as their defense against pathogens is weakened.

  8. Pollen Contaminated With Field-Relevant Levels of Cyhalothrin Affects Honey Bee Survival, Nutritional Physiology, and Pollen Consumption Behavior.

    PubMed

    Dolezal, Adam G; Carrillo-Tripp, Jimena; Miller, W Allen; Bonning, Bryony C; Toth, Amy L

    2016-02-01

    Honey bees are exposed to a variety of environmental factors that impact their health, including nutritional stress, pathogens, and pesticides. In particular, there has been increasing evidence that sublethal exposure to pesticides can cause subtle, yet important effects on honey bee health and behavior. Here, we add to this body of knowledge by presenting data on bee-collected pollen containing sublethal levels of cyhalothrin, a pyrethroid insecticide, which, when fed to young honey bees, resulted in significant changes in lifespan, nutritional physiology,and behavior. For the first time, we show that when young, nest-aged bees are presented with pollen containing field-relevant levels of cyhalothrin, they reduce their consumption of contaminated pollen. This indicates that, at least for some chemicals, young bees are able to detect contamination in pollen and change their behavioral response, even if the contamination levels do not prevent foraging honey bees from collecting the contaminated pollen.

  9. Antidepressants at environmentally relevant concentrations affect predator avoidance behavior of larval fathead minnows (Pimephales promelas).

    USGS Publications Warehouse

    Furlong, Edward T.; Barber, Larry B.; Meghan R. McGee,; Megan A. Buerkley,; Matthew L. Julius,; Vajda, Alan M.; Heiko L. Schoenfuss,; Schultz, Melissa M.; Norris, David O.

    2009-01-01

    The effects of embryonic and larval exposure to environmentally relevant (ng/L) concentrations of common antidepressants, fluoxetine, sertraline, venlafaxine, and bupropion (singularly and in mixture) on C-start escape behavior were evaluated in fathead minnows (Pimephales promelas). Embryos (postfertilization until hatching) were exposed for 5 d and, after hatching, were allowed to grow in control well water until 12 d old. Similarly, posthatch fathead minnows were exposed for 12 d to these compounds. High-speed (1,000 frames/s) video recordings of escape behavior were collected and transferred to National Institutes of Health Image for frame-by- frame analysis of latency periods, escape velocities, and total escape response (combination of latency period and escape velocity). When tested 12 d posthatch, fluoxetine and venlafaxine adversely affected C-start performance of larvae exposed as embryos. Conversely, larvae exposed for 12 d posthatch did not exhibit altered escape responses when exposed to fluoxetine but were affected by venlafaxine and bupropion exposure. Mixtures of these four antidepressant pharmaceuticals slowed predator avoidance behaviors in larval fathead minnows regardless of the exposure window. The direct impact of reduced C-start performance on survival and, ultimately, reproductive fitness provides an avenue to assess the ecological relevance of exposure in an assay of relatively short duration.

  10. Antidepressants at environmentally relevant concentrations affect predator avoidance behavior of larval fathead minnows (Pimephales promelas)

    USGS Publications Warehouse

    Painter, M.M.; Buerkley, M.A.; Julius, M.L.; Vajda, A.M.; Norris, D.O.; Barber, L.B.; Furlong, E.T.; Schultz, M.M.; Schoenfuss, H.L.

    2009-01-01

    The effects of embryonic and larval exposure to environmentally relevant (ng/L) concentrations of common antidepressants, fluoxetine, sertraline, venlafaxine, and bupropion (singularly and in mixture) on C-start escape behavior were evaluated in fathead minnows (Pimephales promelas). Embryos (postfertilization until hatching) were exposed for 5 d and, after hatching, were allowed to grow in control well water until 12 d old. Similarly, posthatch fathead minnows were exposed for 12 d to these compounds. High-speed (1,000 frames/s) video recordings of escape behavior were collected and transferred to National Institutes of Health Image for frame-by-frame analysis of latency periods, escape velocities, and total escape response (combination of latency period and escape velocity). When tested 12 d posthatch, fluoxetine and venlafaxine adversely affected C-start performance of larvae exposed as embryos. Conversely, larvae exposed for 12 d posthatch did not exhibit altered escape responses when exposed to fluoxetine but were affected by venlafaxine and bupropion exposure. Mixtures of these four antidepressant pharmaceuticals slowed predator avoidance behaviors in larval fathead minnows regardless of the exposure window. The direct impact of reduced C-start performance on survival and, ultimately, reproductive fitness provides an avenue to assess the ecological relevance of exposure in an assay of relatively short duration. ?? 2009 SETAC.

  11. A guideline for the identification of environmentally relevant, ionizable organic molecule species.

    PubMed

    Schaffer, Mario; Licha, Tobias

    2014-05-01

    An increasing number of organic compounds detected today in the aquatic environment are ionizable and, therefore, partially or permanently charged (ionic) under the pH conditions encountered in these systems. For evaluating their environmental behavior, which strongly depends on the charge state, the identification of functional groups together with their correct assignment of the respective acidic or basic dissociation constants (pKa) is essential. Despite the growing concern and increasing awareness for ionizable compounds, contradicting and/or confusing information regarding their acid/base properties can be regularly found in the literature, especially when complex structures are encountered. Therefore, we provide a simplified, general, and comprehensive guideline for the identification of ionizable functional groups in organic compounds combined with the correct assignment of their respective pKa values. Beside the explicit definition of basic terms, several tables with more than 30 of the most frequently encountered ionizable compound classes, including their typical pKa value ranges are the centerpiece of the proposed procedure. The straight forward application of the guideline is successfully shown for several environmentally relevant compounds as example. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Sublethal health effects in laboratory rodents from environmentally relevant exposures to oil sands contaminants.

    PubMed

    Rodríguez-Estival, Jaime; North, Michelle A; Smits, Judit E G

    2015-12-01

    Increasing activity of oil sands extraction and processing in northern Alberta is marked by ongoing controversy about the nature and extent of associated environmental impacts. Bitumen contains a mixture of toxic chemicals, including metals and residual polycyclic aromatic hydrocarbons (PAHs), whose release into the environment poses a distinct risk to the surrounding environment, plus wildlife and human health. In the present study, the authors evaluated several subclinical biomarkers of exposure and effect to mixtures of metals (Pb, Cd, and Hg) and/or PAHs (3 alkylated forms) at environmentally relevant concentrations (100-fold and 10-fold higher than the maximum dissolved concentrations found in snow, to simulate a worst-case scenario), using laboratory mice as a model for future studies of small mammals in the wild. Both metals and alkyl-PAHs exposure were associated with 1) increased relative liver, kidney, and spleen size; 2) alterations in the homeostasis of the antioxidant vitamins A and E in liver; and 3) compromised glutathione redox status in testes, with results also indicating synergistic interactions from co-exposure. The combination of morphometric and oxidative stress biomarkers provide reliable and sensitive measures of the response to contaminant exposure in a mammalian model, suggesting associated physiological costs. Based on the present experimental study, the authors propose that wild small mammals will prove to be valuable sentinel species reflecting sublethal health effects from oil sands-related contaminants. The present study's results also present a basis for the interpretation of future field data. © 2015 SETAC.

  13. Model Organisms Retain an “Ecological Memory” of Complex Ecologically Relevant Environmental Variation

    PubMed Central

    Beer, Karlyn D.; Wurtmann, Elisabeth J.; Pinel, Nicolás

    2014-01-01

    Although tractable model organisms are essential to characterize the molecular mechanisms of evolution and adaptation, the ecological relevance of their behavior is not always clear because certain traits are easily lost during long-term laboratory culturing. Here, we demonstrate that despite their long tenure in the laboratory, model organisms retain “ecological memory” of complex environmental changes. We have discovered that Halobacterium salinarum NRC-1, a halophilic archaeon that dominates microbial communities in a dynamically changing hypersaline environment, simultaneously optimizes fitness to total salinity, NaCl concentration, and the [K]/[Mg] ratio. Despite being maintained under controlled conditions over the last 50 years, peaks in the three-dimensional fitness landscape occur in salinity and ionic compositions that are not replicated in laboratory culturing but are routinely observed in the natural hypersaline environment of this organism. Intriguingly, adaptation to variations in ion composition was associated with differential regulation of anaerobic metabolism genes, suggesting an intertwined relationship between responses to oxygen and salinity. Our results suggest that the ecological memory of complex environmental variations is imprinted in the networks for coordinating multiple cellular processes. These coordination networks are also essential for dealing with changes in other physicochemically linked factors present during routine laboratory culturing and, hence, retained in model organisms. PMID:24413600

  14. Toxicological hazard induced by sucralose to environmentally relevant concentrations in common carp (Cyprinus carpio).

    PubMed

    Saucedo-Vence, Karinne; Elizalde-Velázquez, Armando; Dublán-García, Octavio; Galar-Martínez, Marcela; Islas-Flores, Hariz; SanJuan-Reyes, Nely; García-Medina, Sandra; Hernández-Navarro, María Dolores; Gómez-Oliván, Leobardo Manuel

    2017-01-01

    Sucralose (SUC) is an artificial sweetener that is now widely used in North American and Europe; it has been detected in a wide variety of aquatic environments. It is considered safe for human consumption but its effects in the ecosystem have not yet been studied in depth, since limited ecotoxicological data are available in the peer-reviewed literature. This study aimed to evaluate potential SUC-induced toxicological hazard in the blood, brain, gill, liver and muscle of Cyprinus carpio using oxidative stress biomarkers. Carps were exposed to two different environmentally relevant concentrations (0.05 and 155μgL(-1)) for different exposure times (12, 24, 48, 72 and 96h). The following biomarkers were evaluated: lipid peroxidation (LPX), hydroperoxide content (HPC) and protein carbonyl content (PCC), as well as the activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). SUC was determined by high pressure liquid chromatography tandem mass spectrometry techniques (HPLC)-MS/MS. Results show a statically significant increase in LPX, HPC, PCC (P<0.05) especially in gill, brain and muscle, as well as significant changes in the activity of antioxidant enzymes in gill and muscle. Furthermore, the biomarkers employed in this study are useful in the assessment of the environmental impact of this agent on aquatic species. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Bisphenol A exposure at an environmentally relevant dose induces meiotic abnormalities in adult male rats.

    PubMed

    Liu, Chuan; Duan, Weixia; Zhang, Lei; Xu, Shangcheng; Li, Renyan; Chen, Chunhai; He, Mindi; Lu, Yonghui; Wu, Hongjuan; Yu, Zhengping; Zhou, Zhou

    2014-01-01

    Whether environmental exposure to bisphenol A (BPA) may induce reproductive disorders is still controversial but certain studies have reported that BPA may cause meiotic abnormalities in C. elegans and female mice. However, little is known about the effect of BPA on meiosis in adult males. To determine whether BPA exposure at an environmentally relevant dose could induce meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 20 μg/kg body weight (bw)/day for 60 consecutive days. We found that BPA significantly increased the proportion of stage VII seminiferous epithelium and decreased the proportion of stage VIII. Consequently, spermiation was inhibited and spermatogenesis was disrupted. Further investigation revealed that BPA exposure delayed meiosis initiation in the early meiotic stage and induced the accumulation of chromosomal abnormalities and meiotic DNA double-strand breaks (DSBs) in the late meiotic stage. The latter event subsequently activated the phosphatidylinositol 3-kinase-related protein kinase (ATM). Our results suggest that long-term exposure to BPA may lead to continuous meiotic abnormalities and ultimately put mammalian reproductive health at risk.

  16. Sublethal effects on wood frogs chronically exposed to environmentally relevant concentrations of two neonicotinoid insecticides.

    PubMed

    Robinson, Stacey A; Richardson, Sarah D; Dalton, Rebecca L; Maisonneuve, France; Trudeau, Vance L; Pauli, Bruce D; Lee-Jenkins, Stacey S Y

    2017-04-01

    Neonicotinoids are prophylactically used globally on a variety of crops, and there is concern for the potential impacts of neonicotinoids on aquatic ecosystems. The intensive use of pesticides on crops has been identified as a contributor to population declines of amphibians, but currently little is known regarding the sublethal effects of chronic neonicotinoid exposure on amphibians. The objective of the present study was to characterize the sublethal effect(s) of exposure to 3 environmentally relevant concentrations (1 μg/L, 10 μg/L, and 100 μg/L) of 2 neonicotinoids on larval wood frogs (Lithobates sylvaticus) using outdoor mesocosms. We exposed tadpoles to solutions of 2 commercial formulations containing imidacloprid and thiamethoxam, and assessed survival, growth, and development. Exposure to imidacloprid at 10 μg/L and 100 μg/L increased survival and delayed completion of metamorphosis compared with controls. Exposure to thiamethoxam did not influence amphibian responses. There was no significant effect of any treatment on body mass or size of the metamorphs. The results suggest that current usage of imidacloprid and thiamethoxam does not pose a threat to wood frogs. However, further assessment of both direct and indirect effects on subtle sublethal endpoints, and the influence of multiple interacting stressors at various life stages, is needed to fully understand the effects of neonicotinoids on amphibians. Environ Toxicol Chem 2017;36:1101-1109. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

  17. Environmentally relevant concentrations of citalopram partially inhibit feeding in the three-spine stickleback (Gasterosteus aculeatus).

    PubMed

    Kellner, M; Porseryd, T; Porsch-Hällström, I; Hansen, S H; Olsén, K H

    2015-01-01

    Selective Serotonin Re-uptake Inhibitors (SSRI) are mood-altering, psychotropic drugs commonly used in the treatment of depression and other psychological illnesses. Many of them are poorly degraded in sewage treatment plants and enter the environment unaltered. In laboratory studies, they have been demonstrated to affect a wide range of behaviours in aquatic organisms. In this study we investigated the effect of a three-week exposure to 0.15 and 1.5 μg/l of the SSRI citalopram dissolved in the ambient water on the feeding behaviour in three-spine stickleback (Gasterosteus aculeatus). Feeding, measured as the number of attacks performed on a piece of frozen bloodworms during a 10-min period, was reduced by 30-40% in fish exposed to both 0.15 and 1.5 μg/l citalopram. The effects of the environmentally relevant concentration 0.15 μg/l on feeding, an important fitness characteristic, suggests that the ecological significance of environmental SSRI exposure may be pronounced. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. More than inorganic copper is bioavailable to aquatic mosses at environmentally relevant concentrations.

    PubMed

    Ferreira, Daniel; Tousset, Nicolas; Ridame, Céline; Tusseau-Vuillemin, Marie-Hélène

    2008-10-01

    The present study investigates how dissolved organic matter (DOM) alters copper bioavailability at environmentally relevant concentrations (1-5 microg/L of dissolved copper, 1-4 mg/L of dissolved organic copper). A methodology combining two biological endpoints (short-term and steady-state bioaccumulation of copper by the aquatic moss Fontinalis antipyretica) and a sampling of labile copper with diffusion gradient in thin films (DGT) is proposed for batch experiments conducted with mineral water and various DOM, ethylenediaminetetra-acetic acid (EDTA), humic acid, and natural Seine River (France) extracts (hydrophobic and transphilic fractions). All types of DOM reduce the bioavailability of copper to aquatic mosses, and this reduction was more pronounced for the short-term biological endpoint, which was taken as being representative for environmental exposure. Labile copper sampled with DGT made it possible to estimate short-term bioaccumulation in the case of EDTA and natural Seine River extracts. With humic acid solutions, however, labile copper was lower than bioavailable copper. This result suggests that at realistic metal concentrations and with certain types of natural DOM, bioavailable copper might comprise not only inorganic copper but also some weak organic complexes. Hence, labile copper, in situ sampled with DGT, might not systematically overestimate bioavailable copper, as suggested previously on the basis of in vitro toxicity studies.

  19. Assessing the potential risks to zebrafish posed by environmentally relevant copper and silver nanoparticles.

    PubMed

    Chio, Chia-Pin; Chen, Wei-Yu; Chou, Wei-Chun; Hsieh, Nan-Hung; Ling, Min-Pei; Liao, Chung-Min

    2012-03-15

    The manufacture of large quantities of engineered nanomaterials (NMs) may lead to unintended contamination of aquatic ecosystems. Biologically based monitoring techniques need to be developed to detect these emerging NMs. The purpose of this study was to develop a risk-based probability model to predict the potential hazards of nanoecotoxicity toward aquatic organisms posed by waterborne copper and silver nanoparticles (Cu/Ag NPs). Published experimental evidence based on Cu/Ag NP-zebrafish (Danio rerio) systems was adopted as the study data. A Hill model was used to reconstruct a concentration-mortality response profile. A cumulative Weibull predictive model was employed to estimate exposure thresholds. The derived probabilistic model can predict the potential risk of environmentally relevant Cu/Ag NPs for major Taiwanese rivers with predicted environmental concentrations of 0.06 (95% confidence interval (CI): 0.01-0.92) mgL(-1) for Cu NPs and 0.04 (0.01-0.11) mgL(-1) for Ag NPs. The results indicated that estimated thresholds were 0.10-0.48mgL(-1) (95% CI) for Cu NPs and 2.69-2.73mgL(-1) for Ag NPs. The probabilities of a risk quotient (RQ) of >1 ranged 17%-81% for zebrafish exposed to Cu NPs. This study found that Ag NP exposure scenarios posed no significant risks to zebrafish (RQ≪0.1).

  20. Environmentally relevant concentrations of ammonium perchlorate inhibit development and metamorphosis in Xenopus laevis.

    PubMed

    Goleman, Wanda L; Urquidi, Lina J; Anderson, Todd A; Smith, Ernest E; Kendall, Ronald J; Carr, James A

    2002-02-01

    We determined whether environmentally relevant concentrations of ammonium perchlorate alter development and metamorphosis in Xenopus laevis. Eggs and larvae were exposed to varying concentrations of ammonium perchlorate or control medium for 70 d. Most treatment-related mortality was observed within 5 d after exposure and was due in large part to reduced hatching success. The 5- and 70-d median lethal concentrations (LC50s) were 510 +/- 36 mg ammonium perchlorate/L and 223 +/- 13 mg ammonium perchlorate/L, respectively. Ammonium perchlorate did not cause any concentration-related developmental abnormalities at concentrations below the 70-d LC50. Ammonium perchlorate inhibited metamorphosis in a concentration-dependent manner as evident from effects on forelimb emergence, tail resorption, and hindlimb growth. These effects were observed after exposure to ammonium perchlorate concentrations in the parts-per-billion range, at or below concentrations reported in surface waters contaminated with ammonium perchlorate. Ammonium perchlorate significantly inhibited tail resorption after a 14-d exposure in the U.S. Environmental Protection Agency (U.S. EPA) Endocrine Disruptor Screening and Testing Committee (EDSTAC) Tier I frog metamorphosis assay for thyroid disruption in amphibians. We believe that ammonium perchlorate may pose a threat to normal development and growth in natural amphibian populations.

  1. An environmentally relevant organochlorine mixture impairs sperm function and embryo development in the porcine model.

    PubMed

    Campagna, Céline; Guillemette, Christine; Paradis, René; Sirard, Marc-André; Ayotte, Pierre; Bailey, Janice L

    2002-07-01

    We evaluated the effects of an environmentally relevant mixture of more than 15 organochlorines on the development of pig oocytes and sperm during in vitro fertilization (IVF). Oocytes were cocultured with sperm in IVF medium containing increasing concentrations of an organochlorine mixture, similar to that found in women of highly exposed populations. Exposure to the organochlorine mixture diminished oocyte penetration rates and polyspermy in a linear manner. The mixture did not affect rates of cleavage nor development to multicell embryos. However, rates of development to the blastocyst stage were lower at the highest concentration at which oocyte penetration was observed. The same experiment was performed using oocytes that were preexposed during in vitro maturation. This greater exposure to the mixture also reduced penetration in a dose-response manner and affected polyspermy. Frozen-thawed pig sperm were also cultured in IVF medium containing the same organochlorine concentrations. Sperm motility parameters were immediately reduced in a dose-dependent manner by the organochlorines, followed by diminished viability 2 h later. From these results, it appears that reduced sperm quality would account for decreases in fertilization, polyspermy, and blastocyst formation. These results suggest that exposing porcine oocytes and sperm to an environmentally pertinent organochlorine mixture in vitro disrupts the oocyte block to polyspermy, sperm fertility, and further embryonic development, and supports recent concerns that such pollutants harm reproductive health in humans and other species.

  2. Photooxidation of the Antimicrobial, Nonribosomal Peptide Bacitracin A by Singlet Oxygen under Environmentally Relevant Conditions.

    PubMed

    Lundeen, Rachel A; Chu, Chiheng; Sander, Michael; McNeill, Kristopher

    2016-08-16

    Bacitracin is a mixture of nonribosomal peptides (NRPs) that is extensively used as an antibiotic in both human and veterinary medicine. Despite its widespread use over the past six decades, very few studies have addressed the environmental fate of bacitracin and zinc-bacitracin complexes. In this study, the photochemical transformation of bacitracin components (i.e., cyclic dodecapeptides) in the aquatic environment was investigated. A high resolution mass spectrometry (HRMS)-based approach enabled monitoring of the photochemical degradation kinetics of individual bacitracin components, investigation of the relative contribution of reactive oxygen species (e.g., singlet oxygen, (1)O2) in dissolved organic matter-sensitized photoreactions, and identification of oxidative modifications in bacitracin photoproducts. The results of this study support the hypothesis that indirect photochemical oxidation of the histidine (His) residue by (1)O2 is a major degradation pathway for bacitracin A, the most potent congener of the mixture. Furthermore, the photooxidation rate of bacitracin A with (1)O2 decreased upon bacitracin A coordination with Zn(2+), demonstrating that the photochemistry of metal-bound His is different from that of metal-free His. Overall, these results provide insight into the fate of bacitracin components in the aquatic environment and highlight the potential of utilizing this HRMS-based methodology to study transformations of other environmentally relevant NRPs.

  3. Feasibility and relevance of level I substation node counts in oropharyngeal carcinoma.

    PubMed

    Rassekh, Christopher H; O'Malley, Bert W; Bewley, Arnaud F; Montone, Kathleen T; Livolsi, Virginia A; Weinstein, Gregory S

    2016-08-01

    The inclusion of level I in neck dissections for oropharyngeal carcinoma remains controversial. Our objectives were to evaluate the feasibility and relevance of substation node counts in level I of the neck dissection and to determine the specific substation location of metastases in level I in oropharyngeal carcinoma. Sixty specimens were retrospectively analyzed after an orientation using a new paradigm of demarcating level I specimens into 8 substations. Three of the specimens (5%) in this study showed nodal metastasis in level I, one each in 3 different substations. All positive nodes in level I were associated with N+ disease in level II with 2 being radiographically occult (3.3%). Average total node count for level I was 8.1 (range, 2-19). In oropharyngeal carcinoma, substation level I node quantification is feasible and relevant. This study shows a 5% risk to level I with metastasis in 3 different substations. © 2016 Wiley Periodicals, Inc. Head Neck 38:1194-1200, 2016. © 2016 Wiley Periodicals, Inc.

  4. Relemed: sentence-level search engine with relevance score for the MEDLINE database of biomedical articles

    PubMed Central

    Siadaty, Mir S; Shu, Jianfen; Knaus, William A

    2007-01-01

    Background Receiving extraneous articles in response to a query submitted to MEDLINE/PubMed is common. When submitting a multi-word query (which is the majority of queries submitted), the presence of all query words within each article may be a necessary condition for retrieving relevant articles, but not sufficient. Ideally a relationship between the query words in the article is also required. We propose that if two words occur within an article, the probability that a relation between them is explained is higher when the words occur within adjacent sentences versus remote sentences. Therefore, sentence-level concurrence can be used as a surrogate for existence of the relationship between the words. In order to avoid the irrelevant articles, one solution would be to increase the search specificity. Another solution is to estimate a relevance score to sort the retrieved articles. However among the >30 retrieval services available for MEDLINE, only a few estimate a relevance score, and none detects and incorporates the relation between the query words as part of the relevance score. Results We have developed "Relemed", a search engine for MEDLINE. Relemed increases specificity and precision of retrieval by searching for query words within sentences rather than the whole article. It uses sentence-level concurrence as a statistical surrogate for the existence of relationship between the words. It also estimates a relevance score and sorts the results on this basis, thus shifting irrelevant articles lower down the list. In two case studies, we demonstrate that the most relevant articles appear at the top of the Relemed results, while this is not necessarily the case with a PubMed search. We have also shown that a Relemed search includes not only all the articles retrieved by PubMed, but potentially additional relevant articles, due to the extended 'automatic term mapping' and text-word searching features implemented in Relemed. Conclusion By using sentence-level

  5. County-level cumulative environmental quality associated with cancer incidence.

    PubMed

    Jagai, Jyotsna S; Messer, Lynne C; Rappazzo, Kristen M; Gray, Christine L; Grabich, Shannon C; Lobdell, Danelle T

    2017-08-01

    Individual environmental exposures are associated with cancer development; however, environmental exposures occur simultaneously. The Environmental Quality Index (EQI) is a county-level measure of cumulative environmental exposures that occur in 5 domains. The EQI was linked to county-level annual age-adjusted cancer incidence rates from the Surveillance, Epidemiology, and End Results (SEER) Program state cancer profiles. All-site cancer and the top 3 site-specific cancers for male and female subjects were considered. Incident rate differences (IRDs; annual rate difference per 100,000 persons) and 95% confidence intervals (CIs) were estimated using fixed-slope, random intercept multilevel linear regression models. Associations were assessed with domain-specific indices and analyses were stratified by rural/urban status. Comparing the highest quintile/poorest environmental quality with the lowest quintile/best environmental quality for overall EQI, all-site county-level cancer incidence rate was positively associated with poor environmental quality overall (IRD, 38.55; 95% CI, 29.57-47.53) and for male (IRD, 32.60; 95% CI, 16.28-48.91) and female (IRD, 30.34; 95% CI, 20.47-40.21) subjects, indicating a potential increase in cancer incidence with decreasing environmental quality. Rural/urban stratified models demonstrated positive associations comparing the highest with the lowest quintiles for all strata, except the thinly populated/rural stratum and in the metropolitan/urbanized stratum. Prostate and breast cancer demonstrated the strongest positive associations with poor environmental quality. We observed strong positive associations between the EQI and all-site cancer incidence rates, and associations differed by rural/urban status and environmental domain. Research focusing on single environmental exposures in cancer development may not address the broader environmental context in which cancers develop, and future research should address cumulative environmental

  6. Complex mixtures: relevance of combined exposure to substances at low dose levels.

    PubMed

    Leeman, Winfried R; Krul, Lisette; Houben, Geert F

    2013-08-01

    Upon analysis of chemically complex food matrices a forest of peaks is likely to be found. Identification of these peaks and concurrent determination of the toxicological relevance upon exposure is very time consuming, expensive and often requires animal studies. Recently, a safety assessment framework based on the Threshold of Toxicological Concern (TTC) was published to assess the safety of chemically complex matrices more efficiently. In this safety assessment framework, the toxicological relevance of exposure to unidentified substances in chemically complex food matrices can be related to the Cramer class III TTC threshold, currently set at 90 μg/day. However, possible additive or synergistic effects of combined exposure is not covered. The current evaluation describes the relevance of combined low dose exposure to unidentified substances in chemically complex food matrices. It is concluded that to some extent cumulative effects at exposure levels for each substance at or below the Cramer class III TTC threshold, being present in a complex mixture including food, might occur. However the health relevance of possible cumulative effects at this dose level is considered to be that low that a need for a correction factor to cover possible cumulative effects is very low to absent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Environmental Education Inservice Training Packet for the Intermediate Level.

    ERIC Educational Resources Information Center

    Upper Mississippi River ECO-Center, Thomson, IL.

    The inservice teacher training packet, developed with help from the environmental education program of the Upper Mississippi River ECO-Center, is designed to help intermediate-level teachers develop teaching skills which will enable them to introduce environmental or outdoor education to their students and develop those concepts, attitudes, and…

  8. County-level environmental quality and associations with cancer incidence

    EPA Science Inventory

    Cancer has been associated with individual ambient environmental exposures such as PM2.5 and arsenic. However, the role of the overall ambient environment is not well-understood. A novel county-level Environmental Quality Index (EQI) was developed for all U.S. counties (n=3,141)...

  9. Environmental Education Inservice Training Packet for the Intermediate Level.

    ERIC Educational Resources Information Center

    Upper Mississippi River ECO-Center, Thomson, IL.

    The inservice teacher training packet, developed with help from the environmental education program of the Upper Mississippi River ECO-Center, is designed to help intermediate-level teachers develop teaching skills which will enable them to introduce environmental or outdoor education to their students and develop those concepts, attitudes, and…

  10. County-level environmental quality and associations with cancer incidence

    EPA Science Inventory

    Cancer has been associated with individual ambient environmental exposures such as PM2.5 and arsenic. However, the role of the overall ambient environment is not well-understood. A novel county-level Environmental Quality Index (EQI) was developed for all U.S. counties (n=3,141)...

  11. Susceptibility of Alloy 22 to Environmentally Assisted Cracking in Yucca Mountain Relevant Environments

    SciTech Connect

    Estill, J C; King, K J; Fix, D V; Spurlock, D G; Hust, G A; Gordon, S R; McCright, R D; Rebak, R B; Gordon, G M

    2002-01-30

    In its current design, the high level nuclear waste containers will include an external layer of Alloy 22 (Ni-22Cr-13Mo-3W-3Fe). Since over their life-time the containers may be exposed to multi-ionic aqueous environments, a potential degradation mode of the outer layer could be environmental assisted cracking (EAC). The objective of the current research work was to quantify the susceptibility of Alloy 22 to EAC in a several environmental conditions including solution composition, temperature and electrochemical potential. The susceptibility to EAC was evaluated using the constant deformation technique, the compact specimen--low cycle fatigue method and the slow strain rate test (SSRT). The alloy was tested in the wrought mill annealed (MA) and in the as-welded conditions. Results show that Alloy 22 was extremely resistant to EAC in a wide range of environmental conditions. Using SSRT, Alloy 22 was found susceptible to EAC in one electrolyte at one temperature and at one electrochemical potential.

  12. Aquatic toxicity of sertraline to Pimephales promelas at environmentally relevant surface water pH.

    PubMed

    Valenti, Theodore W; Perez-Hurtado, Pilar; Chambliss, C Kevin; Brooks, Bryan W

    2009-12-01

    Researchers recognize that ionization state may influence the biological activity of weak acids and bases. Dissociation in aqueous solutions is controlled by the pKa of a compound and the pH of the matrix. Because many pharmaceuticals are implicitly designed as ionizable compounds, site-specific variability in pH of receiving waters may introduce uncertainty to ecological risk assessments. The present study employed 48-h and 7-d toxicity tests with Pimephales promelas exposed to the model weak base pharmaceutical sertraline over a gradient of environmentally relevant surface water pHs. The 48-h experiments were completed in triplicate, and the average lethal concentration values were 647, 205, and 72 microL sertraline at pH 6.5, 7.5, and 8.5, respectively. Survivorship, growth, and feeding rate (a nontraditional endpoint linked by other researchers to sertraline's specific mode of action) were monitored during the 7-d experiment. Adverse effects were more pronounced when individuals were exposed to sertraline at pH 8.5 compared to pH 7.5 and 6.5. The pH-dependent toxicological relationships from these studies were related to in-stream pH data for two streams in the Brazos River basin of central Texas, USA. This predictive approach was taken because of the scarcity of environmental analytical data for sertraline. The results of this study emphasized temporal variability associated with in-stream pH linked to seasonal differences within and between these spatially related systems. Relating site-specific pH variability of surface waters to ionization state may allow researchers to reduce uncertainty during ecological risk assessment of pharmaceuticals by improving estimates of biological effects associated with exposure.

  13. Sex reversal effects on Caiman latirostris exposed to environmentally relevant doses of the xenoestrogen bisphenol A.

    PubMed

    Stoker, C; Rey, F; Rodriguez, H; Ramos, J G; Sirosky, P; Larriera, A; Luque, E H; Muñoz-de-Toro, M

    2003-10-01

    Exposure to environmental contaminants known as endocrine disruptors (EDs) alters the development and function of reproductive organs in several species. Bisphenol A (BPA) is an estrogenic chemical that leaches from dental materials and plastic food and beverage containers. BPA has been found in sewage, surface and drinking water, and therefore poses a potentially significant risk for human and wildlife. Prenatal exposure of rodents to environmentally relevant doses of BPA alters the development of the reproductive organs of male and female offspring. Species with temperature dependent sex determination (TSD) could act as sentinels of ecosystem health by providing sensitive biomarkers of endocrine disruptor's effects. We selected Caiman latirostris as an animal model to study endocrine disruption caused by BPA. The aim of this study was to determine whether exposure in ovum to BPA could cause estrogen-like effects on the reproductive system of C. latirostris. Sex determination and gonadal histoarchitecture were the endpoints evaluated after in ovum exposure to different doses of BPA and 17beta-estradiol (E(2)). We confirmed that C. latirostris is a species with TSD and additionally demonstrated that BPA causes estrogen-like developmental effects by reversing gonadal sex and altering gonadal histoarchitecture. Differences in responses to BPA and E(2) in our in vivo system were on the order of 100-fold. In contrast published in vitro studies have reported differences on the order of 10,000x or more. These results support the utility of C. latirostris, a species in which sex determination is temperature dependent, as a tool in assessing estrogenic activity in vivo and as a sentinel to monitor EDs in aquatic environment.

  14. Sublethal genotoxicity and cell alterations by organophosphorus pesticides in MCF-7 cells: implications for environmentally relevant concentrations.

    PubMed

    Ukpebor, Justina; Llabjani, Valon; Martin, Francis L; Halsall, Crispin J

    2011-03-01

    Organophosphorus pesticide (OPP) toxicity is believed to be mediated through inhibition of acetylcholinesterase (AChE). Given their widespread distribution in aquatic systems and their ability to undergo chemical transformation, their environmental impacts at sublethal concentrations in nontarget organisms have become an important question. We conducted a number of mammalian-cell genotoxic and gene expression assays and examined cellular biochemical changes that followed low-dose exposure of MCF-7 cells to fenitrothion, diazinon, and the aqueous degradate of diazinon, 2-isopropyl-6-methyl-4-pyrimidinol (IMP). After exposure to the OPPs at low concentrations (10(-12) M to 10(-8) M), greater than twofold elevations in micronucleus formation were noted in MCF-7 cell cultures that went on to exhibit greater than 75% clonogenic survival; these levels of chromosomal damage were comparable to those induced by 10(-6) M benzo[a]pyrene, a known genotoxic agent. At this low concentration range, a fenitrothion-induced twofold elevation in B-cell leukemia/lymphoma-2 (BCL-2) and cytochrome P450 isoenzyme (CYP1A1) gene expressions was observed. Principal component analysis-linear discriminant analysis (PCA-LDA) of derived infrared (IR) spectra of vehicle control (nonexposed) and OPP-exposed cells highlighted that both fenitrothion and diazinon induced marked biochemical alterations in the lipid, protein, and DNA/RNA absorbance regions. Our findings demonstrate that the two OPP parent chemicals and IMP degradate can mediate a number of toxic effects or cellular alterations at very low concentrations. These are independent of just selective inhibition of AChE, with potential consequences for nontarget organisms exposed at environmentally relevant concentrations. Further assays on relevant aquatic organism cell lines are now recommended to understand the mechanistic low-dose toxicity of these chemicals present in aquatic systems. Copyright © 2011 SETAC.

  15. Nitrite- and Nitrate-Dependent Methanotrophs - Environmental Detection and Relevance in Freshwater Ecosystems

    NASA Astrophysics Data System (ADS)

    Ettwig, K. F.

    2014-12-01

    Humans continue to have an enormous impact on global C and N cycles. While a clear stimulation of methane emissions through human activities is evident, the role of also increasingly released nitrogenous compounds as electron acceptors for microbial methane oxidation is not well constrained. We have developed diverse methods for environmental detection of nitrate(NO3-)- and - predominantly - nitrite(NO2-)-dependent methanotrophs, which have been applied to several freshwater environments. In contrast to most metabolically flexible heterotrophic denitrifiers, the microorganisms responsible for methane-dependent nitrate/nitrite reduction seem to be specialized to use methane only, grow slowly and employ pathways different from each other and from model organisms, which necessitate new approaches for the assessment of their environmental relevance. Nitrite-dependent methane oxidation is carried out by bacteria of the NC10 phylum, whereas nitrate-dependent methane oxidizers are close relatives of methanogenic archaea and sulfate-dependent anaerobic methanotrophs (ANME-2). Laboratory enrichment cultures of the nitrite-reducing methanotroph Methylomirabilis oxyfera (NC10 phylum) have formed the basis for its genetic and physiological characterization and the development of several independent methods for its sensitive detection. M. oxyfera differs from all known microorganisms by encoding an incomplete denitrification pathway, in which the last 2 steps, the reduction of NO via N2O to N2, apparently is replaced by the dismutation of NO to N2 and O2. The intracellularly produced O2 is used for methane oxidation via a methane monooxygenase, analogously to the phylogenetically unrelated proteobacterial methanotrophs. But unlike in proteobacteria, C is not assimilated from methane, but rather CO2, with important consequences for the interpretation of environmental isotope labelling studies. In addition, M. oxyfera is characterized by a distinct PLFA profile, including

  16. Exposure to an environmentally relevant mixture of brominated flame retardants affects fetal development in Sprague-Dawley rats.

    PubMed

    Berger, Robert G; Lefèvre, Pavine L C; Ernest, Sheila R; Wade, Michael G; Ma, Yi-Qian; Rawn, Dorothea F K; Gaertner, Dean W; Robaire, Bernard; Hales, Barbara F

    2014-06-05

    Brominated flame retardants are incorporated into a wide variety of consumer products and are known to enter into the surrounding environment, leading to human exposure. There is accumulating evidence that these compounds have adverse effects on reproduction and development in humans and animal models. Animal studies have generally characterized the outcome of exposure to a single technical mixture or congener. Here, we determined the impact of exposure of rats prior to mating and during gestation to a mixture representative of congener levels found in North American household dust. Adult female Sprague-Dawley rats were fed a diet containing 0, 0.75, 250 or 750mg/kg of a mixture of flame retardants (polybrominated diphenyl ethers, hexabromocyclododecane) from two weeks prior to mating to gestation day 20. This formulation delivered nominal doses of 0, 0.06, 20 and 60mg/kg body weight/day. The lowest dose approximates high human exposures based on house dust levels and the dust ingestion rates of toddlers. Litter size and resorption sites were counted and fetal development evaluated. No effects on maternal health, litter size, fetal viability, weights, crown rump lengths or sex ratios were detected. The proportion of litters with fetuses with anomalies of the digits (soft tissue syndactyly or malposition of the distal phalanges) was increased significantly in the low (0.06mg/kg/day) dose group. Skeletal analysis revealed a decreased ossification of the sixth sternebra at all exposure levels. Thus, exposure to an environmentally relevant mixture of brominated flame retardants results in developmental abnormalities in the absence of apparent maternal toxicity. The relevance of these findings for predicting human risk is yet to be determined.

  17. Effects of environmentally relevant mixtures of major ions on a freshwater mussel.

    PubMed

    Ciparis, Serena; Phipps, Andrew; Soucek, David J; Zipper, Carl E; Jones, Jess W

    2015-12-01

    The Clinch and Powell Rivers (Virginia, USA) support diverse mussel assemblages. Extensive coal mining occurs in both watersheds. In large reaches of both rivers, major ion concentrations are elevated and mussels have been extirpated or are declining. We conducted a laboratory study to assess major ion effects on growth and survival of juvenile Villosa iris. Mussels were exposed to pond water and diluted pond water with environmentally relevant major ion mixtures for 55 days. Two treatments were tested to mimic low-flow concentrations of Ca(2+), Mg(2+), [Formula: see text] , [Formula: see text] , K(+) and Cl(-) in the Clinch and Powell Rivers, total ion concentrations of 419 mg/L and 942 mg/L, respectively. Mussel survival (>90%) and growth in the two treatments showed little variation, and were not significantly different than in diluted pond water (control). Results suggest that major ion chronic toxicity is not the primary cause for mussel declines in the Clinch and Powell Rivers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. TLR4 is a target of environmentally relevant concentration of lead.

    PubMed

    Luna, Ana L; Acosta-Saavedra, Leonor C; Martínez, Marcela; Torres-Avilés, Nallely; Gómez, Rocío; Calderón-Aranda, Emma S

    2012-11-15

    Lead (Pb) alters the susceptibility to different pathogens suggesting that macrophage-mediated defense mechanisms, through activation of toll-like receptors (TLRs), may be affected by Pb. The aim of this study was to test whether activation of TLR4 is a targeted molecule to the effect of environmentally relevant Pb concentrations (0.05, 0.5 and 5μg/dL). The function of macrophages activated through TLR4 was evaluated using as TLR4 ligand lipopolysaccharides (LPSs) from two different pathogens: Escherichia coli and Salmonella typhimurium. Pb induced proliferation, increased the NO(-) baseline, IL-1β and IL-6 secretion. Interestingly, Pb exposure induced differential effects on cells stimulated with the two LPS used: in macrophages stimulated with LPS from E. coli, Pb caused an early decrease in proliferation, increase NO(-) production, and decrease IL-6 and TNF-α secretion; in macrophages stimulated with LPS from S. typhimurium, Pb decreased proliferation after 36h, induced a biphasic effect on NO(-) production, and enhance the secretion of IL-1β, IL-6 and TNF-α. Results suggest that TLR4 is a target for the Pb effect, which up to 5.0μg/dL affect immune competence against pathogens, dependent on the bacterial species. This effect may be attributable to structural differences that determine LPS affinity for TLR4.

  19. Effects of tributyltin (TBT) on Xenopus tropicalis embryos at environmentally relevant concentrations.

    PubMed

    Guo, Suzhen; Qian, Lijuan; Shi, Huahong; Barry, Terence; Cao, Qinzhen; Liu, Junqi

    2010-04-01

    Tributyltin (TBT) has been widely used as a biocide in antifouling paints and is a known endocrine disrupting chemical. In this paper, we exposed embryos of Xenopus tropicalis to 50-400ngL(-1) tributyltin chloride. TBT significantly decreased the survival rate, reduced the body length and retarded the development of embryos after 24, 36 and 48h of exposure. These effects of TBT were concentration- and time-dependent. Embryos treated with TBT showed multiple malformations. The most obvious alterations were abnormal eyes, enlarged proctodaeum, narrow fins, and skin hypopigmentation. Enlarged proctodaeum and narrow fins were mainly observed after 36 and 48h of exposure. The loss of eye pigmentation or the absence of external eyes occurred after 24 and 36h of exposure, while extended lenses or edemas of eyes were more commonly observed after 48h of exposure. Additional malformations included: small anterior region of heads, pericardial edemas, enlarged trunks, and bent tails. These results suggested that TBT is very toxic to X. tropicalis embryos at environmentally relevant concentrations.

  20. Ru(III) catalyzed permanganate oxidation of aniline at environmentally relevant pH.

    PubMed

    Zhang, Jing; Zhang, Ying; Wang, Hui; Guan, Xiaohong

    2014-07-01

    Ru(III) was employed as catalyst for aniline oxidation by permanganate at environmentally relevant pH for the first time. Ru(III) could significantly improve the oxidation rate of aniline by 5-24 times with its concentration increasing from 2.5 to 15 μmol/L. The reaction of Ru(III) catalyzed permanganate oxidation of aniline was first-order with respect to aniline, permanganate and Ru(III), respectively. Thus the oxidation kinetics can be described by a third-order rate law. Aniline degradation by Ru(III) catalyzed permanganate oxidation was markedly influenced by pH, and the second-order rate constant (ktapp) decreased from 643.20 to 2.67 (mol/L)⁻¹sec⁻¹ with increasing pH from 4.0 to 9.0, which was possibly due to the decrease of permanganate oxidation potential with increasing pH. In both the uncatalytic and catalytic permanganate oxidation, six byproducts of aniline were identified in UPLC-MS/MS analysis. Ru(III), as an electron shuttle, was oxidized by permanganate to Ru(VI) and Ru(VII), which acted the co-oxidants for decomposition of aniline. Although Ru(III) could catalyze permanganate oxidation of aniline effectively, dosing homogeneous Ru(III) into water would lead to a second pollution. Therefore, efforts would be made to investigate the catalytic performance of supported Ru(III) toward permanganate oxidation in our future study.

  1. The attachment of colloidal particles to environmentally relevant surfaces and the effect of particle shape.

    PubMed

    McNew, Coy P; Kananizadeh, Negin; Li, Yusong; LeBoeuf, Eugene J

    2017-02-01

    Despite the prevalence of nonspherical colloidal particles, the role of particle shape in the transport of colloids is largely understudied. This study investigates the attachment of colloidal particles onto environmentally relevant surfaces while varying particle shape and ionic strength. Using quartz crystal microbalance and atomic force microscopy measurements, the role of particle shape was elucidated and possible mechanisms discussed. The attachment of both spherical and stretched polystyrene colloidal particles onto a smooth alginate-coated silica surface showed qualitative agreement with DLVO theory. Attachment onto a Harpeth humic acid (HHA) surface, however, significantly deviated from DLVO theory due to its high surface heterogeneity and extended confirmation from the silica surface. This extended confirmation provided increased potential for spherical particle entanglement, while the enlarged major axis of the stretched particles hindered their ability to attach. As ionic strength increased, the HHA layer condensed and provided less potential for spherical particle entanglement and therefore the selectivity for spherical particle attachment vanished. The findings presented in this study suggest that colloidal particle shape may play a complex and important role in predicting the transport of colloidal particles, especially in the presence of natural organic matter-coated surfaces. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Environmentally relevant concentrations of pharmaceuticals influence the initial adhesion of bacteria.

    PubMed

    Schreiber, Frank; Szewzyk, Ulrich

    2008-05-30

    Pharmaceuticals are abundant at low concentrations (i.e. ng L(-1); microg L(-1)) in natural aquatic systems. However, very little is known about their effects on microorganisms. This study investigated the influence of the pharmaceuticals phenazone, amoxicillin and erythromycin, at low, non-toxic concentrations (i.e. 0.5-50 microg L(-1)), on the initial adhesion of bacteria to uncoated and iron-coated polystyrene. The influence of the pharmaceuticals on the initial adhesion of bacterial pure cultures (Escherichia coli, Aquabacterium commune, Bacillus subtilis) isolated from natural aquatic systems, was investigated with a plate assay. Initial adhesion of the pure cultures depended on the selected pharmaceutical, its concentration, the bacterial strain and the adhesion surface. Different combinations of these parameters resulted in inhibition, enhancement or had no effect on initial adhesion. In addition, a continuous flow system was used to investigate the influence of the pharmaceuticals on the initial adhesion of a drinking water microbial community. The drinking water community showed decreased adhesion in the presence of the pharmaceuticals regardless of adhesion surface. The results show that pharmaceuticals at environmentally relevant concentrations can influence the initial adhesion of bacteria. Thus, pharmaceutical compounds that are introduced to natural aquatic systems are able to exert subtle effects on bacteria.

  3. Clinical Relevance of Environmental Factors in the Pathogenesis of Autoimmune Thyroid Disease

    PubMed Central

    2016-01-01

    Genetic factors contribute for about 70% to 80% and environmental factors for about 20% to 30% to the pathogenesis of autoimmune thyroid disease (AITD). Relatives of AITD patients carry a risk to contract AITD themselves. The 5-year risk can be quantified by the so-called Thyroid Events Amsterdam-score, based on serum thyroid-stimulating hormone, thyroid peroxidase (TPO)-antibodies and family history. Subjects at risk may ask what they can do to prevent development of AITD. This review summarizes what is known about modulation of exposure to environmental factors in terms of AITD prevention. To stop smoking decreases the risk on Graves disease but increases the risk on Hashimoto disease. Moderate alcohol intake provides some protection against both Graves and Hashimoto disease. Low selenium intake is associated with a higher prevalence of thyroid autoimmunity, but evidence that selenium supplementation may lower TPO antibodies and prevent subclinical hypothyroidism remains inconclusive. Low serum vitamin D levels are associated with a higher prevalence of TPO antibodies, but intervention studies with extra vitamin D have not been done yet. Stress may provoke Graves hyperthyroidism but not Hashimoto thyroiditis. Estrogen use have been linked to a lower prevalence of Graves disease. The postpartum period is associated with an increased risk of AITD. Taking together, preventive interventions to diminish the risk of AITD are few, not always feasible, and probably of limited efficacy. PMID:27184015

  4. Mechanism of toxicity of pesticides acting at complex I: relevance to environmental etiologies of Parkinson's disease.

    PubMed

    Sherer, Todd B; Richardson, Jason R; Testa, Claudia M; Seo, Byoung Boo; Panov, Alexander V; Yagi, Takao; Matsuno-Yagi, Akemi; Miller, Gary W; Greenamyre, J Timothy

    2007-03-01

    Parkinson's disease (PD) has been linked to mitochondrial dysfunction and pesticide exposure. The pesticide rotenone (ROT) inhibits complex I and reproduces features of PD in animal models, suggesting that environmental agents that inhibit complex I may contribute to PD. We have previously demonstrated that ROT toxicity is dependent upon complex I inhibition and that oxidative stress is the primary mechanism of toxicity. In this study, we examined the in vitro toxicity and mechanism of action of several putative complex I inhibitors that are commonly used as pesticides. The rank order of toxicity of pesticides to neuroblastoma cells was pyridaben > rotenone > fenpyroximate > fenazaquin > tebunfenpyrad. A similar order of potency was observed for reduction of ATP levels and competition for (3)H-dihydrorotenone (DHR) binding to complex I, with the exception of pyridaben (PYR). Neuroblastoma cells stably expressing the ROT-insensitive NADH dehydrogenase of Saccharomyces cerevisiae (NDI1) were resistant to these pesticides, demonstrating the requirement of complex I inhibition for toxicity. We further found that PYR was a more potent inhibitor of mitochondrial respiration and caused more oxidative damage than ROT. The oxidative damage could be attenuated by NDI1 or by the antioxidants alpha-tocopherol and coenzyme Q(10). PYR was also highly toxic to midbrain organotypic slices. These data demonstrate that, in addition to ROT, several commercially used pesticides directly inhibit complex I, cause oxidative damage, and suggest that further study is warranted into environmental agents that inhibit complex I for their potential role in PD.

  5. Clinical Relevance of Environmental Factors in the Pathogenesis of Autoimmune Thyroid Disease.

    PubMed

    Wiersinga, Wilmar M

    2016-06-01

    Genetic factors contribute for about 70% to 80% and environmental factors for about 20% to 30% to the pathogenesis of autoimmune thyroid disease (AITD). Relatives of AITD patients carry a risk to contract AITD themselves. The 5-year risk can be quantified by the so-called Thyroid Events Amsterdam-score, based on serum thyroid-stimulating hormone, thyroid peroxidase (TPO)-antibodies and family history. Subjects at risk may ask what they can do to prevent development of AITD. This review summarizes what is known about modulation of exposure to environmental factors in terms of AITD prevention. To stop smoking decreases the risk on Graves disease but increases the risk on Hashimoto disease. Moderate alcohol intake provides some protection against both Graves and Hashimoto disease. Low selenium intake is associated with a higher prevalence of thyroid autoimmunity, but evidence that selenium supplementation may lower TPO antibodies and prevent subclinical hypothyroidism remains inconclusive. Low serum vitamin D levels are associated with a higher prevalence of TPO antibodies, but intervention studies with extra vitamin D have not been done yet. Stress may provoke Graves hyperthyroidism but not Hashimoto thyroiditis. Estrogen use have been linked to a lower prevalence of Graves disease. The postpartum period is associated with an increased risk of AITD. Taking together, preventive interventions to diminish the risk of AITD are few, not always feasible, and probably of limited efficacy.

  6. The environmental behaviour of polychlorinated phenols and its relevance to cork forest ecosystems: a review.

    PubMed

    McLellan, Iain; Carvalho, Mariana; Silva Pereira, Cristina; Hursthouse, Andrew; Morrison, Calum; Tatner, Paul; Martins, Isabel; San Romão, M Vitória; Leitão, Maria

    2007-10-01

    Pentachlorophenol (PCP) has been used as a herbicide, biocide and preservative worldwide since the 1930s and as a result, extensive and prolonged contamination exists. The environmental impact increases when its many degradation products are taken into consideration. A number of chloroanisols and their related chlorophenols have been found in cork slabs collected from Portuguese oak tree forests before stopper manufacturing, and contamination by PCP and polychlorinated anisole (PCA) has been detected in Canadian forests. It is suggested that the use of polychlorinated phenols, in particular PCP, is thought to be a cause of the cork taint problem in wine, a major socio-economic impact not only for industry but on sensitive and highly biodiverse ecosystems. It also highlights particular issues relating to the regional regulation of potentially toxic chemicals and global economics world wide. To fully understand the impact of contamination sources, the mechanisms responsible for the fate and transport of PCP and its degradation products and assessment of their environmental behaviour is required. This review looks at the current state of knowledge of soil sorption, fate and bioavailability and identifies the challenges of degradation product identification and the contradictory evidence from field and laboratory observations. The need for a systematic evaluation of PCP contamination in relation to cork forest ecosystems and transfer of PCP between trophic levels is emphasised by discrepancies in bioaccumulation and toxicity. This is essential to enable long term management of not only transboundary contaminants, but also the sustainable management of socially and economically important forest ecosystems.

  7. β-Cyclodextrin Polymer Network Sequesters Perfluorooctanoic Acid at Environmentally Relevant Concentrations.

    PubMed

    Xiao, Leilei; Ling, Yuhan; Alsbaiee, Alaaeddin; Li, Chenjun; Helbling, Damian E; Dichtel, William R

    2017-06-14

    Per- and poly fluorinated alkyl substances (PFASs), notably perfluorooctanoic acid (PFOA), contaminate many ground and surface waters and are environmentally persistent. The performance limitations of existing remediation methods motivate efforts to develop effective adsorbents. Here we report a β-cyclodextrin (β-CD)-based polymer network with higher affinity for PFOA compared to powdered activated carbon, along with comparable capacity and kinetics. The β-CD polymer reduces PFOA concentrations from 1 μg L(-1) to <10 ng L(-1), at least 7 times lower than the 2016 U.S. EPA advisory level (70 ng L(-1)), and was regenerated and reused multiple times by washing with MeOH. The performance of the polymer is unaffected by humic acid, a component of natural organic matter that fouls activated carbons. These results are promising for treating PFOA-contaminated water and demonstrate the versatility of β-CD-based adsorbents.

  8. Antioxidant responses in Meretrix meretrix exposed to environmentally relevant doses of tributyltin.

    PubMed

    Huang, Zhouying; Chen, Yixin; Zhao, Yang; Zuo, Zhenghong; Chen, Mei; Wang, Chonggang

    2005-07-01

    The effects on reduced glutathione (GSH) levels, glutathione-S-transferases (GST) and glutathione peroxidase (GPx) activities of digestive gland in Meretrix meretrix exposed to tributyltin (TBT) at environmental levels (0.1, 1, 10ng/L as Sn), in experimental condition, were evaluated. The GST activities in 0.1ng/L groups were significantly elevated after exposure for 2 days, and were significantly inhibited after exposure to 10ng/L TBT for 8 and 20 days. The GPx activities were mainly induced by TBT exposure, except the GPx activities in 10ng/L groups were significantly inhibited after exposure for 2 days. The GSH content was significantly decreased with prolonged exposure. The GSH content, GST and GPx activities in all exposure groups, transferred to clean recovery tanks for 20 days, were recovered to the level corresponding to that of the control group. Taken together, our present studies indicate that exposure to TBT may induce strong production of reactive oxygen species in the clams.

  9. Mycobacteria in Municipal Wastewater Treatment and Reuse: Microbial Diversity for Screening the Occurrence of Clinically and Environmentally Relevant Species in Arid Regions.

    PubMed

    Amha, Yamrot M; Anwar, M Zohaib; Kumaraswamy, Rajkumari; Henschel, Andreas; Ahmad, Farrukh

    2017-03-07

    With accumulating evidence of pulmonary infection via aerosolized nontuberculous mycobacteria (NTM), it is important to characterize their persistence in wastewater treatment, especially in arid regions where treated municipal wastewater is extensively reused. To achieve this goal, microbial diversity of the genus Mycobacterium was screened for clinically and environmentally relevant species using pyrosequencing. Analysis of the postdisinfected treated wastewater showed the presence of clinically relevant slow growers like M. kansasii, M. szulgai, M. gordonae, and M. asiaticum; however, in these samples, rapid growers like M. mageritense occurred at much higher relative abundance. M. asiaticum and M. mageritense have been isolated in pulmonary samples from NTM-infected patients in the region. Diversity analysis along the treatment train found environmentally relevant organisms like M. poriferae and M. insubricum to increase in relative abundance across the chlorine disinfection step. A comparison to qPCR results across the chlorine disinfection step saw no significant change in slow grower counts at CT disinfection values ≤90 mg·min/L; only an increase to 180 mg·min/L in late May brought slow growers to below detection levels. The study confirms the occurrence of clinically and environmentally relevant mycobacteria in treated municipal wastewater, suggesting the need for vigilant monitoring of treated wastewater quality and disinfection effectiveness prior to reuse.

  10. Transport of fluorescently labeled hydroxyapatite nanoparticles in saturated granular media at environmentally relevant concentrations of surfactants

    SciTech Connect

    Wang, Dengjun; Su, Chuming; Liu, Chongxuan; Zhou, Dongmei

    2014-05-01

    Hydroxyapatite nanoparticle (nHAP) is being used to remediate soils and aquifers contaminated with metals and radionuclides; however, the mobility of nHAP is still poorly understood in subsurface granular environments. In this study, transport and retention kinetics of alizarin red S (ARS)-labeled nHAP were investigated in water-saturated quartz sand at low concentrations of surfactants: sodium dodecyl benzene sulfonate (SDBS, an anionic surfactant, 0–50 mg L–1) and cetyltrimethylammonium bromide (CTAB, a cationic surfactant, 0–5 mg L–1). Both surfactants were found to have a marked effect on the electrokinetic properties of ARS-nHAP and, consequently, on their transport and retention behaviors. Transport of nanoparticles (NPs) increased significantly with increasing SDBS concentration, largely because of enhanced colloidal stability and reduced aggregate size arising from enhanced electrostatic, osmotic, and elastic-steric repulsions between ARS-nHAP and sand grains. Conversely, transport decreased significantly in the presence of increasing CTAB concentrations due to reduced surface charge and consequential enhanced aggregation of the NPs. Osmotic and elastic-steric repulsions played only a minor role in enhancing the colloidal stability of ARS-nHAP in the presence of CTAB. Retention profiles of ARS-nHAP exhibited hyperexponential-shapes (decreasing rates of retention with increasing distance) for all conditions tested, and became more pronounced as CTAB concentration increased. The phenomenon was attributed to the aggregation and ripening of ARS-nHAP in the presence of surfactants, particularly CTAB. Overall, the present study suggests that surfactants at environmentally relevant concentrations may be an important consideration in employing nHAP for engineered in-situ remediation of certain metals and radionuclides in contaminated soils and aquifers.

  11. Short-term effects of environmentally relevant concentrations of EDC mixtures on Mytilus galloprovincialis digestive gland.

    PubMed

    Canesi, Laura; Borghi, Cristina; Ciacci, Caterina; Fabbri, Rita; Lorusso, Lucia Cecilia; Vergani, Laura; Marcomini, Antonio; Poiana, Giulio

    2008-05-30

    Endocrine disrupting compounds (EDCs), including both natural estrogens and estrogenic chemicals, are almost ubiquitous in the aquatic environment. In the marine bivalve Mytilus galloprovincialis different estrogenic compounds, both individually and in mixtures, were shown to affect the immune function both in vitro and in vivo. Moreover, individual estrogens, the natural estrogen 17beta-estradiol (E(2)) and the xenoestrogen bisphenol A (BPA), have been recently demonstrated to alter functional parameters and gene expression in mussel digestive gland, a tissue that plays a central role in metabolism and in nutrient distribution to the gonad during gamete maturation, with possible consequences on gametogenesis. In this work, the possible effects of a synthetic mixture of EDCs on the digestive gland were evaluated. The mixture contained seven estrogenic chemicals (17beta-estradiol, 17alpha-ethynyl estradiol, mestranol (MES), nonylphenol, nonylphenol monoethoxylate carboxylate (NP1EC), BPA, benzophenone (BP)), in proportions similar to those previously found in water samples of a coastal lagoon. Mussels were injected with different concentrations of the mixture (approximate nominal concentrations of total EDCs: 0.0177, 0.177, 1.77 and 177 ng/g dw) and tissues sampled 24 h post-injection. The mixture induced significant changes in lysosomal biomarkers (lysosomal membrane stability (LMS), neutral lipid (NL) and lipofuscin (LF) accumulation) as well as in the activities of catalase, glutathione transferase (GST), and of the glycolytic enzymes phosphofructokinase (PFK) and pyruvate kinase (PK). Moreover, downregulation of the gene transcription for the Mytilus estrogen receptor MeER1 isoform and for catalase, as evaluated by quantitative RT-PCR, were observed. Significant changes in lysosomal biomarkers, enzyme activities and gene transcription were also recorded at 72 h post-injection. The results demonstrate that short-term exposure to environmentally relevant

  12. Gestational and Early Postnatal Exposure to an Environmentally Relevant Mixture of Brominated Flame Retardants: General Toxicity and Skeletal Variations.

    PubMed

    Tung, Emily W Y; Yan, Han; Lefèvre, Pavine L C; Berger, Robert G; Rawn, Dorothea F K; Gaertner, Dean W; Kawata, Alice; Rigden, Marc; Robaire, Bernard; Hales, Barbara F; Wade, Michael G

    2016-06-01

    Brominated flame retardants (BFRs) are stable environmental contaminants known to exert endocrine-disrupting effects. Developmental exposure to polybrominated diphenyl ethers (PBDEs) is correlated with impaired thyroid hormone signaling, as well as estrogenic and anti-androgenic effects. As previous studies have focused on a single congener or technical mixture, the purpose of the current study was to examine the effects of gestational and early postnatal exposure to an environmentally relevant mixture of BFRs designed to reflect house dust levels of PBDEs and hexabromocyclododecane on postnatal developmental outcomes. Pregnant Sprague-Dawley rats were exposed to the PBDE mixture from preconception to weaning (PND 21) through the diet containing 0, 0.75, 250, and 750 mg mixture/kg diet. BFR exposure induced transient reductions in body weight at PND 35 in male and from PND 30-45 in female offspring (250 and 750 mg/kg). Liver weights (PND 21) and xenobiotic metabolizing enzyme activities (PND 21 and 46) were increased in both male and female offspring exposed to 250 and 750 mg/kg diets. Furthermore, serum T4 levels were reduced at PND 21 in both,male and female offspring (250 and 750 mg/kg). At PND 21, Serum alkaline phosphatase (ALP) was decreased in males exposed to 750 mg/kg dietat, and females exposed to 250 and 750 mg/kg diets. At PND 46 ALP was significantly elevated in males (250 and 750 mg/kg). Variations in the cervical vertebrae and phalanges were observed in pups at PND 4 (250 and 750 mg/kg). Therefore, BFR exposure during gestation through to weaning alters developmental programming in the offspring. The persistence of BFRs in the environment remains a cause for concern with regards to developmental toxicity.

  13. Exposure of Female Rats to an Environmentally Relevant Mixture of Brominated Flame Retardants Targets the Ovary, Affecting Folliculogenesis and Steroidogenesis.

    PubMed

    Lefèvre, Pavine L C; Berger, Robert G; Ernest, Sheila R; Gaertner, Dean W; Rawn, Dorothea F K; Wade, Michael G; Robaire, Bernard; Hales, Barbara F

    2016-01-01

    Brominated flame retardants (BFRs) are incorporated into various consumer products to prevent flame propagation. These compounds leach into the domestic environment, resulting in chronic exposure and contamination. Pregnancy failure is associated with high levels of BFRs in human follicular fluid, raising serious questions regarding their impact on female reproductive health. The goal of this study is to elucidate the effects of an environmentally relevant BFR mixture on female rat ovarian functions (i.e., folliculogenesis and steroidogenesis). A BFR dietary mixture formulated to mimic the relative BFR congener levels in North American house dust was administered to adult female Sprague-Dawley rats from 2 to 3 wk before mating until Gestational Day 20; these diets were designed to deliver nominal doses of 0, 0.06, 20, or 60 mg/kg/day of the BFR mixture. Exposure to BFRs triggered an approximately 50% increase in the numbers of preantral and antral follicles and an enlargement of the antral follicles in the ovaries of the dams. A significant reduction in the expression of catalase, an antioxidant enzyme, and downregulation of the expression of insulin-like factor 3 (Insl3) and 17alpha-hydroxylase (Cyp17a1) were observed in the ovary. In addition, BFR exposure affected steroidogenesis; we observed a significant decrease in circulating 17-hydroxypregnenolone and an increase in testosterone concentrations in BFR-exposed dams. Thus, BFRs target ovarian function in the rat, adversely affecting both folliculogenesis and steroidogenesis.

  14. DNA methylation pyrosequencing assay is applicable for the assessment of epigenetic active environmental or clinical relevant chemicals.

    PubMed

    Florea, Ana-Maria

    2013-01-01

    Exposure of cells and organisms to stressors might result in epigenetic changes. Here it is shown that investigation of DNA methylation using pyrosequencing is an alternative for in vitro and in vivo toxicological testing of epigenetic effects induced by chemicals and drugs. An in vitro evaluation of global and CpG site specific DNA methylation upon treatment of cells with chemicals/drugs is shown. Bisulfite genomic sequencing of methylation controls showed high methylation of LINE1 in methylation positive control and low methylation in the negative controls. The CpG sites within the LINE1 element are methylated at different levels. In vitro cell cultures show a methylation level ranging from 56% to 49%. Cultures of drug resistant tumor cells show significant hypomethylation as compared with the originating nonresistant tumor cells. The in vitro testing of epigenetically active chemicals (5-methyl-2'-deoxycytidine and trichostatin A) revealed a significant change of LINE1 methylation status upon treatment, while specific CpG sites were more prone to demethylation than others (focal methylation). In conclusion, DNA methylation using pyrosequencing might be used not only for testing epigenetic toxins/drugs but also in risk assessment of drugs, food, and environmental relevant pollutants.

  15. Cumulative toxicity of an environmentally relevant mixture of nine regulated disinfection by-products in a multigenerational rat reproductive bioassay

    EPA Science Inventory

    CUMULATIVE TOXICITY OF AN ENVIRONMENTALLY RELEVANT MIXTURE OF NINE REGULATED DISINFECTION BY-PRODUCTS IN A MULTIGENERATIONAL RAT REPRODUCTIVE BIOASSAY J E Simmons, GR. Klinefelter, JM Goldman, AB DeAngelo, DS Best, A McDonald, LF Strader, AS Murr, JD Suarez, MH George, ES Hunte...

  16. Cumulative toxicity of an environmentally relevant mixture of nine regulated disinfection by-products in a multigenerational rat reproductive bioassay

    EPA Science Inventory

    CUMULATIVE TOXICITY OF AN ENVIRONMENTALLY RELEVANT MIXTURE OF NINE REGULATED DISINFECTION BY-PRODUCTS IN A MULTIGENERATIONAL RAT REPRODUCTIVE BIOASSAY J E Simmons, GR. Klinefelter, JM Goldman, AB DeAngelo, DS Best, A McDonald, LF Strader, AS Murr, JD Suarez, MH George, ES Hunte...

  17. Development of a Heuristic Knowledge Base for the Selection of Applicable or Relevant and Appropriate Environmental Requirements

    DTIC Science & Technology

    1992-09-01

    RELEVANT AND APPROPRIATE ENVIRONMENTAL REQUIREMENTS THESIS Scott J. Borg, Captain, USAF Gerald B. Puetz, Captain. USAF AFIT/GEE/CEC/92S-5 v , 93-04104...66 V . Conclusions and Recommendations ......................... 67 Overview ........................................ 67 Summary of...Bibliography ................................................ 89 V ita ....................................................... 95 v Figure Page 1. Nine

  18. A Study of the Environmental Risk Perceptions and Environmental Awareness Levels of High School Students

    ERIC Educational Resources Information Center

    Anilan, Burcu

    2014-01-01

    This descriptive research was conducted to determine the levels of environmental risk perceptions and environmental awareness of high school students in Eskisehir. High school students in the towns Tepebasi and Odunpazari in the 2010-2011 school years constitute the universe of the research. The sample of the research is composed of 413 high…

  19. Environmental Studies and Environmental Science at GCE '0' and 'A' Level.

    ERIC Educational Resources Information Center

    Gayford, Christopher G.

    1983-01-01

    Reports on environmental studies/science at General Certificate of Examination (GCE) ordinary ("0") and advanced ("A") levels. Questionnaires were used to survey teachers (focusing on their professional training and why they teach environmental studies/science courses) and to determine the relationship between environmental…

  20. A Study of the Environmental Risk Perceptions and Environmental Awareness Levels of High School Students

    ERIC Educational Resources Information Center

    Anilan, Burcu

    2014-01-01

    This descriptive research was conducted to determine the levels of environmental risk perceptions and environmental awareness of high school students in Eskisehir. High school students in the towns Tepebasi and Odunpazari in the 2010-2011 school years constitute the universe of the research. The sample of the research is composed of 413 high…

  1. Environmental influence on trace element levels in human hair

    SciTech Connect

    Limic, N.; Valkovic, V.

    1986-12-01

    Trace element content of human hair depends on many factors. It has been shown by a large number of investigators that environmental factors play an important role. Elements from air particulates, water, shampoo or other media get incorporated into the hair structure. Here a model is proposed in which different contributions to trace element levels in human hair are factorized and the environmental contribution to the radial and longitudinal concentration profiles can be calculated. With the proper understanding of environmental contamination, hair analysis has better chances of being used as a diagnostic tool.

  2. Clinical relevance of β₂-glycoprotein-I plasma levels in antiphospholipid syndrome (APS).

    PubMed

    Banzato, Alessandra; Pengo, Vittorio

    2014-06-01

    Antiphospholipid syndrome (APS) is characterized by the presence of antiphospholipid (aPL) antibodies associated with thrombosis or pregnancy morbidity. The antibodies mainly involved in this disorder are directed against β2-glycoprotein I (β2-GPI). β2-GPI plasma level is usually not reported in studies on APS, because it is not regarded as relevant to the diagnosis and prognosis of APS. Nevertheless its measurement may be important for understanding the pathophysiology of the syndrome. This review summarizes available data from the literature on plasma concentrations of β2-GPI in patients with different antibody profiles.

  3. Free and Open Source GIS Tools: Role and Relevance in the Environmental Assessment Community

    EPA Science Inventory

    The presence of an explicit geographical context in most environmental decisions can complicate assessment and selection of management options. These decisions typically involve numerous data sources, complex environmental and ecological processes and their associated models, ris...

  4. Free and Open Source GIS Tools: Role and Relevance in the Environmental Assessment Community

    EPA Science Inventory

    The presence of an explicit geographical context in most environmental decisions can complicate assessment and selection of management options. These decisions typically involve numerous data sources, complex environmental and ecological processes and their associated models, ris...

  5. Environmental management systems at the industrial park level in China.

    PubMed

    Geng, Yong; Côté, Raymond

    2003-06-01

    Environmental management systems (EMSs), such as International Organization for Standardization (ISO) 14001, can be used as a tool in China by industrial park managers to improve their environmental performance. This article uses the case of the Dalian Economic and Technological Development Zone (DETDZ) to show how to establish a comprehensive environmental management system (CEMS) according to the ISO 14001 standard at the industrial park level by considering local realities. The particularly interesting feature of this case study is the use of a CEMS (in this case, ISO 14001) by the administrative group of the DETDZ to develop a more comprehensive approach to the wide range of environmental issues that they face in running the zone. In essence the goal is to address many of the issues at the level of the zone. The incentives, benefits, and barriers associated with implementing ISO 14001 are described. However, implementation of an EMS should not be thought of as the ultimate objective for an industrial park's environmental management. The next steps include encouraging further public participation and taking an integrated approach leading to an industrial ecosystem, which can realize better environmental performance at the industrial park level.

  6. Polychlorinated Biphenyl Sources, Emissions and Environmental Levels in School Buildings

    EPA Science Inventory

    Characterize levels of PCBs in air, dust, soil and on surfaces at six schoolsApply an exposure model for estimating children’s exposures to PCBs in schoolsEvaluate which routes of exposure are likely to be the most importantProvide information relevant for developing manage...

  7. Polychlorinated Biphenyl Sources, Emissions and Environmental Levels in School Buildings

    EPA Science Inventory

    Characterize levels of PCBs in air, dust, soil and on surfaces at six schoolsApply an exposure model for estimating children’s exposures to PCBs in schoolsEvaluate which routes of exposure are likely to be the most importantProvide information relevant for developing manage...

  8. Determination of carbon-14 in environmental level, solid reference materials.

    PubMed

    Blowers, Paul; Caborn, Jane; Dell, Tony; Gingell, Terry; Harms, Arvic; Long, Stephanie; Sleep, Darren; Stewart, Charlie; Walker, Jill; Warwick, Phil E

    2011-10-01

    An intercomparison exercise to determine the (14)C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing (14)C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  9. Regulatory standards applicable or relevant to the independent Hanford environmental surveillance and oversight program

    SciTech Connect

    King, S.E.; Hendrickson, P.L.; Siegel, M.R.; Woodruff, M.G. ); Belfiglio, J.; Elliott, R.W. )

    1990-03-01

    The authors reviewed federal and state statutes and regulations, as well as Department of Energy (DOE) orders and other guidance material, for potential applicability to the environmental surveillance program conducted for the Hanford site by the Pacific Northwest Laboratory (PNL). There are no federal or state statutes or regulations which are directly applicable to the environmental surveillance program. However, other regulatory schemes, while not directly applicable to the environmental surveillance program, are important insofar as they are indicative of regulatory concern and direction. Because of the evolving nature of environmental regulations, this area needs to be closely monitored for future impact on environmental surveillance activities. 9 refs.,

  10. In utero exposure to environmentally relevant concentrations of PCB 153 and PCB 118 disrupts fetal testis development in sheep.

    PubMed

    Krogenæs, Anette K; Ropstad, Erik; Gutleb, Arno C; Hårdnes, Nina; Berg, Vidar; Dahl, Ellen; Fowler, Paul A

    2014-01-01

    Polychlorinated biphenyls (PCB) are environmental pollutants linked to adverse health effects including endocrine disruption and disturbance of reproductive development. This study aimed to determine whether exposure of pregnant sheep to three different mixtures of PCB 153 and PCB 118 affected fetal testis development. Ewes were treated by oral gavage from mating until euthanasia (d 134), producing three groups of fetuses with distinct adipose tissue PCB levels: high PCB 153/low PCB 118 (n = 13), high PCB 118/low PCB 153 (n = 14), and low PCB 153/low PCB 118 (n = 14). Fetal testes and blood samples were collected for investigation of testosterone, testis morphology, and testis proteome. The body weight of the offspring was lower in the high PCB compared to the low PCB group, but there were no significant differences in testis weight between groups when corrected for body weight. PCB exposure did not markedly affect circulating testosterone. There were no significant differences between groups in number of seminiferous tubules, Sertoli cell only tubules, and ratio between relative areas of seminiferous tubules and interstitium. Two-dimensional (2D) gel-based proteomics was used to screen for proteomic alterations in the high exposed groups relative to low PCB 153/low PCB 118 group. Twenty-six significantly altered spots were identified by liquid chromatography (LC)-mass spectroscopy (MS)/MS. Changes in protein regulation affected cellular processes as stress response, protein synthesis, and cytoskeleton regulation. The study demonstrates that in utero exposure to different environmental relevant PCB mixtures exerted subtle effects on developing fetal testis proteome but did not significantly disturb testis morphology and testosterone production.

  11. Nanoparticle dispersion in environmentally relevant culture media: a TiO2 case study and considerations for a general approach

    NASA Astrophysics Data System (ADS)

    Horst, Allison M.; Ji, Zhaoxia; Holden, Patricia A.

    2012-08-01

    Nanoparticle exposure in toxicity studies requires that nanoparticles are bioavailable by remaining highly dispersed in culture media. However, reported dispersion approaches are variable, mostly study-specific, and not transferable owing to their empirical basis. Furthermore, many published approaches employ proteinaceous dispersants in rich laboratory media, both of which represent end members in environmental scenarios. Here, a systematic approach was developed to disperse initially agglomerated TiO2 nanoparticles (Aeroxide® TiO2 P25, Evonik, NJ; primary particle size range 6.4-73.8 nm) in oligotrophic culture medium for environmentally relevant bacterial toxicity studies. Based on understanding particle-particle interactions in aqueous media and maintaining environmental relevance, the approach involves (1) quantifying the relationship between pH and zeta potential to determine the point of zero charge of select nanoparticles in water; (2) nominating, then testing and selecting, environmentally relevant stabilizing agents; and (3) dispersing via "condition and capture" whereby stock dry powder nanoparticles are sonicated in pre-conditioned (with base, or acid, plus stabilizing agent) water, then diluted into culture media. The "condition and capture" principle is transferable to other nanoparticle and media chemistries: simultaneously, mechanically and electrostatically, nanoparticles can be dispersed with surrounding stabilizers that coat and sterically hinder reagglomeration in the culture medium.

  12. Environmentally relevant dose of arsenic interferes in functions of human monocytes derived dendritic cells.

    PubMed

    Bahari, Abbas; Salmani, Vahid

    2017-06-05

    Arsenic is a major environmental pollutant and highly hazardous toxin to human health, which well established as carcinogen and immune deregulatory properties. Dendritic cells (DCs) have a pivotal role in cell-mediated immunity for T-cell activation and antigen presentation. In this study, T cell activation, some key functional genes expression, cell stability and phagocytosis capacity of human monocytes derived DCs (MDDCs) were analyzed after in vitro exposure to very low dose of arsenic for 12 and 24h. Arsenic decreased continually phagocytosis capacity of MDDCs. Furthermore, down-regulation of the cell-surface expression of the co-stimulatory molecule CD40 after 24h post treatment with arsenic, confirmed arsenic interferers in the phagocytosis process. Pro inflammatory cytokines, IL1β and TNFα were more expressed in arsenic-treated MDDCs while IL6 transiently was down regulated. In general, our novel findings here strongly suggest that low level of arsenic dysregulates four fundamental immune processes of DCs. Mechanistically; this could explain the observed immunodeficiency activity of Arsenic, and give direction for comprehension the pathogenesis of Arsenic-induced diseases. Copyright © 2017. Published by Elsevier B.V.

  13. Bringing policy relevance and scientific discipline to environmental risk assessment for genetically modified crops.

    PubMed

    Herman, Rod A; Garcia-Alonso, Monica; Layton, Raymond; Raybould, Alan

    2013-09-01

    Although public opinion is important in deciding what is valued by society, governments have determined that scientific expertise is required to evaluate potential environmental effects of genetically modified (GM) crops. We suggest how to evaluate rigorously the environmental effects of GM crops in the context of a scientific investigation. Following a disciplined scientific approach to environmental risk assessment (ERA) for GM crops should help resolve controversy in identifying and addressing risk.

  14. Using environmental heterogeneity to plan for sea-level rise.

    PubMed

    Hunter, Elizabeth A; Nibbelink, Nathan P

    2017-02-27

    Environmental heterogeneity is increasingly being used to select conservation areas that will provide for future biodiversity under a variety of climate scenarios. This approach, termed conserving nature's stage (CNS), assumes environmental features respond to climate change more slowly than biological communities, but will CNS be effective if the stage were to change as rapidly as the climate? We tested the effectiveness of using CNS to select sites in salt marshes for conservation in coastal Georgia (U.S.A.), where environmental features will change rapidly as sea level rises. We calculated species diversity based on distributions of 7 bird species with a variety of niches in Georgia salt marshes. Environmental heterogeneity was assessed across six landscape gradients (e.g., elevation, salinity, and patch area). We used 2 approaches to select sites with high environmental heterogeneity: site complementarity (environmental diversity [ED]) and local environmental heterogeneity (environmental richness [ER]). Sites selected based on ER predicted present-day species diversity better than randomly selected sites (up to an 8.1% improvement), were resilient to areal loss from SLR (1.0% average areal loss by 2050 compared with 0.9% loss of randomly selected sites), and provided habitat to a threatened species (0.63 average occupancy compared with 0.6 average occupancy of randomly selected sites). Sites selected based on ED predicted species diversity no better or worse than random and were not resilient to SLR (2.9% average areal loss by 2050). Despite the discrepancy between the 2 approaches, CNS is a viable strategy for conservation site selection in salt marshes because the ER approach was successful. It has potential for application in other coastal areas where SLR will affect environmental features, but its performance may depend on the magnitude of geological changes caused by SLR. Our results indicate that conservation planners that had heretofore excluded low

  15. Environmental Education at University Level: Trends and Data.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France). Centre for Educational Research and Innovation.

    This report is based, in part, on the results of a workshop on Environmental Education at the University Level convened by the Centre for Educational Research and Innovation (CERI) in Tours, France. During this workshop, participants from the Organization for Economic Cooperation and Development (OECD) countries analyzed the serious, urgent need…

  16. Environmental Studies. The Construction of an 'A' Level Syllabus.

    ERIC Educational Resources Information Center

    Carson, S. McB.

    In response to the increasing social concern for the quality of the environment and its conservation, and the need to ensure that all pupils in their final years of schooling be brought to share that concern, teachers in Hertfordshire, England, have constructed an 'A' level curriculum or syllabus of environmental studies for the sixth form. Based…

  17. County-level environmental quality and associations with individual - and county-level preterm birth

    EPA Science Inventory

    Human health is influenced by simultaneous exposure to stressors and amenities, but research usually considers single exposures. We constructed a county-level Environmental Quality Index (EQI) using principal components analysis with data from five domains (air, water, land, buil...

  18. Nanoscale zerovalent iron (nZVI) at environmentally relevant concentrations induced multigenerational reproductive toxicity in Caenorhabditis elegans.

    PubMed

    Yang, Ying-Fei; Chen, Pei-Jen; Liao, Vivian Hsiu-Chuan

    2016-05-01

    Nanoscale zerovalent iron (nZVI) is widely used with large scale for environmental remediation for in situ or ex situ applications. The potential impact of nZVI on biota at environmentally relevant concentrations needs to be elucidated. In this study, the reproductive toxicities of three irons species: carboxymethyl cellulose (CMC)-stabilized nZVI, nanoscale iron oxide (nFe3O4), and ferrous ion (Fe(II)aq) in the soil-dwelling nematode Caenorhabditis elegans were examined. In addition, the generational transfer of reproductive toxicity of CMC-nZVI on C. elegans was investigated. The results showed that CMC-nZVI, nFe3O4, and Fe(II)aq did not cause significant mortality after 24 h exposure at the examined concentrations. Reproductive toxicity assays revealed that CMC-nZVI, nFe3O4, and Fe(II)aq significantly decreased offsprings in parental generation (F0) in accompany with the increased intracellular reactive oxygen species (ROS). Furthermore, the reproductive toxicity of CMC-nZVI at environmentally relevant concentrations was transferrable from the F0 to the F1 and F2 generations, but then recovered in the F3 and F4 generations. Further evidence showed that total irons were accumulated in the F0 and F1 generations of C. elegans after CMC-nZVI parental exposure. This study demonstrated that environmentally relevant concentrations of CMC-nZVI induced multigenerational reproductive toxicity which can be ascribed to its high production of ROS in F0 generation, toxicity of Fe(II)aq, and iron accumulation in C. elegans. Since nZVI is widely used for environmental remediation, considering the multigenerational toxicity, this study thus implicates a potential environmental risk of nZVI-induced nanotoxicity in the environment.

  19. META-ANALYSIS OF THE LIFE STYLE FACTORS RELEVANT TO ENVIRONMENTAL HAZARDS FOR THE AGING POPULATION

    EPA Science Inventory

    The goal of this U.S. Environmental Protection Agency (EPA) study is to characterize activity patterns, physiological changes, and environmental exposures for the aging population. Meta analysis was performed on more than 2000 reviewed articles to evaluate the lifestyle factors ...

  20. META-ANALYSIS OF THE LIFE STYLE FACTORS RELEVANT TO ENVIRONMENTAL HAZARDS FOR THE AGING POPULATION

    EPA Science Inventory

    The goal of this U.S. Environmental Protection Agency (EPA) study is to characterize activity patterns, physiological changes, and environmental exposures for the aging population. Meta analysis was performed on more than 2000 reviewed articles to evaluate the lifestyle factors ...

  1. Naphthalene Mothballs: Emerging and Recurring Issues and their Relevance to Environmental Health.

    PubMed

    Sudakin, Daniel L; Stone, David L; Power, Laura

    2011-01-01

    Naphthalene is a polycyclic aromatic hydrocarbon that is commonly encountered in indoor and outdoor environments. There is growing awareness of the environmental health risks associated with inhalation exposure to naphthalene in the indoor environment. While there are numerous potential sources of naphthalene indoors, the use of mothballs can be a significant contributor to ambient concentrations. This review article describes recurring and emerging environmental health issues relating to mothballs containing naphthalene. The toxicology and health effects of naphthalene exposure are reviewed, with discussion of high-risk populations and risk mitigation strategies. Environmental health professionals should be aware of mothball use in the home, and recognize risks associated with accidental exposure and misuse.

  2. Environmentally relevant impacts of nano-TiO2 on abiotic degradation of bisphenol A under sunlight irradiation.

    PubMed

    Wu, Wei; Shan, Guoqiang; Wang, Shanfeng; Zhu, Lingyan; Yue, Longfei; Xiang, Qian; Zhang, Yinqing; Li, Zhuo

    2016-09-01

    Understanding the effects of nano-TiO2 particles on the environmental behaviors of organic pollutants in natural aquatic environments is of paramount importance considering that large amount of nano-TiO2 is being released in the environment. In this study, the effect of nano-TiO2 on the degradation of bisphenol A (BPA) in water was investigated under simulated solar light irradiation. The results indicated that nano-TiO2 at environmentally relevant concentration (1 mg/L) could significantly facilitate the abiotic degradation of BPA (also at low concentration) under mild solar light irradiation, with the pseudo first-order rate constant (kobs) for BPA degradation raised by 1-2 orders of magnitude. As reflected by the inhibition experiments, hydroxyl radicals (OHs) and superoxide radical species were the predominant active species responsible for BPA degradation. The reaction was affected by water pH, and the degradation rate was higher at acidic or alkaline conditions than that at neutral condition. Humic acid (HA) also affected the reaction rate, depending on its concentration. At lower concentration (the mass ratio of HA/nano-TiO2 was 0.1:1), HA improved the dispersion and stability of nano-TiO2 in aquatic environment. As a result, the yield of OHs by nano-TiO2 under sunlight irradiation increased and BPA degradation was facilitated. When the HA concentration increased, a coating of HA formed on the surface of nano-TiO2. Although nano-TiO2 became more stable, the light absorption by nano-TiO2 was significantly reduced due to the strong light absorption of the HA coated on the surface. As a consequence, the yield of OH decreased and BPA degradation was depressed. The results imply that nano-TiO2 at low concentration may distinctly mediate BPA degradation, and can contribute to the natural attenuation of some organic pollutants in aquatic environment with low level of HA. However, this process would be significantly reduced in the presence of high level of HA.

  3. The Effects of Relevance and Confidence Strategies on Writing Apprehension, Motivational Levels, and Writing Performance on Undergraduate Composition Students

    ERIC Educational Resources Information Center

    Spain, Linda Monk

    2009-01-01

    This study investigated writing apprehension, motivational levels, and writing performance of 68 undergraduates enrolled in four freshman composition courses during one semester. Participants in the treatment groups received relevance, confidence, or a combination of relevance and confidence motivational strategies based on Keller's ARCS model. In…

  4. Postnatal testosterone levels and disorder relevant behavior in the second year of life.

    PubMed

    Saenz, Janet; Alexander, Gerianne M

    2013-09-01

    The objective of the current study was to investigate the relationship between testosterone collected at 3-4 months of age and sex-linked disorder-relevant behaviors in the second year of life. Eighty-four children participated at 3-4 (when salivary testosterone levels were obtained and second to fourth digit ratios were measured) and 18-24 months of age (when behavioral ratings of aggression and verbal ability were coded from two 8-min play sessions). Parents also completed the Brief Infant-Toddler Social and Emotional Assessment, and the four subscales (Internalizing, Externalizing, Dysregulation, and Autism Spectrum Disorder) were used to indicate child specific problems. Greater postnatal testosterone levels in early infancy were predictive of more male-typical behaviors in the second year of life (i.e., more autism spectrum behaviors, less time vocalizing, and more Internalizing Problems). These results support the hypothesis that early infancy may be another critical period for the development of gender-linked behavior.

  5. International safeguards relevant to geologic disposal of high-level wastes and spent fuels

    SciTech Connect

    Pillay, K.K.S.; Picard, R.R.

    1989-01-01

    Spent fuels from once-through fuel cycles placed in underground repositories have the potential to become attractive targets for diversion and/or theft because of their valuable material content and decreasing radioactivity. The first geologic repository in the US, as currently designed, will contain approximately 500 Mt of plutonium, 60,000 Mt of uranium and a host of other fissile and strategically important elements. This paper identifies some of the international safeguards issues relevant to the various proposed scenarios for disposing of the spent fuel. In the context of the US program for geologic disposal of spent fuels, this paper highlights several issues that should be addressed in the near term by US industries, the Department of Energy, and the Nuclear Regulatory Commission before the geologic repositories for spent fuels become a reality. Based on US spent fuel discharges, an example is presented to illustrate the enormity of the problem of verifying spent fuel inventories. The geologic disposal scenario for high-level wastes originating from defense facilities produced a practicably irrecoverable'' waste form. Therefore, safeguards issues for geologic disposal of high-level waste now in the US are less pressing. 56 refs. , 2 figs.

  6. Omics of the marine medaka (Oryzias melastigma) and its relevance to marine environmental research.

    PubMed

    Kim, Bo-Mi; Kim, Jaebum; Choi, Ik-Young; Raisuddin, Sheikh; Au, Doris W T; Leung, Kenneth M Y; Wu, Rudolf S S; Rhee, Jae-Sung; Lee, Jae-Seong

    2016-02-01

    In recent years, the marine medaka (Oryzias melastigma), also known as the Indian medaka or brackish medaka, has been recognized as a model fish species for ecotoxicology and environmental research in the Asian region. O. melastigma has several promising features for research, which include a short generation period (3-4 months), daily spawning, small size (3-4 cm), transparent embryos, sexual dimorphism, and ease of mass culture in the laboratory. There have been extensive transcriptome and genome studies on the marine medaka in the past decade. Such omics data can be useful in understanding the signal transduction pathways of small teleosts in response to environmental stressors. An omics-integrated approach in the study of the marine medaka is important for strengthening its role as a small fish model for marine environmental studies. In this review, we present current omics information about the marine medaka and discuss its potential applications in the study of various molecular pathways that can be targets of marine environmental stressors, such as chemical pollutants. We believe that this review will encourage the use of this small fish as a model species in marine environmental research.

  7. Factors influencing environmental attitude: The relationship between environmental attitude defensibility and cognitive reasoning level

    NASA Astrophysics Data System (ADS)

    Yount, James R.; Horton, Phillip B.

    The purpose of this study was to investigate the relationship between factors believed to contribute to the formation of environmental attitudes by college nonscience majors. Key relationships addressed were the effects of a university environmental studies course on (a) environmental attitudes, (b) the amount of factual information that is brought to bear on an environmental attitude decision (defensibility), and (c) the linkages between the affective and the cognitive domains of freshman and sophomore students. When compared to the control group, the students who attended an environmental studies class did not significantly change their attitudes, but they did exhibit increases in their total [F(3, 132) = 5.91, p < 0.01] and count [F(3, 132) = 4.86, p < 0.01] levels of defensibility. These findings corroborate work performed by Kinsey (1978) and Kinsey and Wheatley (1980, 1984). In addition, students in the environmental studies course who had higher cognitive reasoning scores were more prone to increase defensibility [F(6, 129) = 3.78, p < 0.01]. These data imply a linkage between cognitive and affective domains in the environmental attitude decision-making process.

  8. Environmental factors associated with blood lead levels in Venezuelan children.

    PubMed

    Rojas, M; Squillante, G; Medina, E; de Rojas, O; Sarmiento, A

    2000-06-01

    A preliminary study explored the relative contribution of residential sources of lead exposure on mentally challenged children who attend "special education" institutions (GI) compared to a group of age and sex matched school children (G2). We captured descriptive information and analyzed demographic variables, personal and household information, medical effects, environmental exposure factors, and children habits. Home paint, dust, soil, and water sampling was conducted and blood lead (BPb) levels determined. Eighteen G1 and 20 G2 children were studied. The mean G1 BPb was 16.9 +/- 7.9 microg/dl and was significantly higher than that in G2. Fifty percent of G1 children had PbB >20 microg/dl and 72.2% were >10 microg/dl. Low muscular strength, decreased osteotendinose reflexes, fine and gross motricity, deficient equilibrium, and hipotonic muscular tone coincided with >18 microg/dl BPb levels. In 61.1% of G1 homes paint lead levels were higher than permissible levels and 33.3% had dust lead exceeding that level. The high BPb levels in G1 probably resulted from ingestion of household paint, dust, and soil via "hand-to-mouth" activity. Environmental exposure to lead can be an important source of lead intake by infants and children and could affect neurological development. This study provides new insights currently unavailable for these children in Venezuela.

  9. Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

    NASA Astrophysics Data System (ADS)

    Singer, Brett C.; Hodgson, Alfred T.; Nazaroff, William W.

    Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m 3 furnished room over a 3-h period 6-7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h -1. Organic gas concentrations were measured every few days over 4-h "smoking", 10-h "post-smoking" and 10-h "background" periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by ˜50% for 3-EP, and by 2-3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds

  10. Effects of an environmentally-relevant mixture of pyrethroid insecticides on spontaneous activity in primary cortical networks on microelectrode arrays.

    PubMed

    Johnstone, Andrew F M; Strickland, Jenna D; Crofton, Kevin M; Gennings, Chris; Shafer, Timothy J

    2017-05-01

    Pyrethroid insecticides exert their insecticidal and toxicological effects primarily by disrupting voltage-gated sodium channel (VGSC) function, resulting in altered neuronal excitability. Numerous studies of individual pyrethroids have characterized effects on mammalian VGSC function and neuronal excitability, yet studies examining effects of complex pyrethroid mixtures in mammalian neurons, especially in environmentally relevant mixture ratios, are limited. In the present study, concentration-response functions were characterized for five pyrethroids (permethrin, deltamethrin, cypermethrin, β-cyfluthrin and esfenvalerate) in an in vitro preparation containing cortical neurons and glia. As a metric of neuronal network activity, spontaneous mean network firing rates (MFR) were measured using microelectorde arrays (MEAs). In addition, the effect of a complex and exposure relevant mixture of the five pyrethroids (containing 52% permethrin, 28.8% cypermethrin, 12.9% β-cyfluthrin, 3.4% deltamethrin and 2.7% esfenvalerate) was also measured. Data were modeled to determine whether effects of the pyrethroid mixture were predicted by dose-addition. At concentrations up to 10μM, all compounds except permethrin reduced MFR. Deltamethrin and β-cyfluthrin were the most potent and reduced MFR by as much as 60 and 50%, respectively, while cypermethrin and esfenvalerate were of approximately equal potency and reduced MFR by only ∼20% at the highest concentration. Permethrin caused small (∼24% maximum), concentration-dependent increases in MFR. Effects of the environmentally relevant mixture did not depart from the prediction of dose-addition. These data demonstrate that an environmentally relevant mixture caused dose-additive effects on spontaneous neuronal network activity in vitro, and is consistent with other in vitro and in vivo assessments of pyrethroid mixtures. Published by Elsevier B.V.

  11. Changes in the growth, but not the survival, of American kestrels (Falco sparverius) exposed to environmentally relevant polybrominated diphenyl ethers.

    PubMed

    Fernie, Kim J; Laird Shutt, J; Ritchie, Ian J; Letcher, Robert J; Drouillard, Ken; Bird, David M

    2006-08-01

    Polybrominated diphenyl ether (PBDEs) concentrations are increasing exponentially in biota. We studied the growth of American kestrel (Falco sparverius) nestlings exposed in ovo and during development to environmentally relevant PBDE congeners and concentrations. Eggs within each clutch, divided between groups by laying sequence, were injected into the air cell at 19 days of incubation with safflower oil or penta-BDE congeners BDE-47, -99, -100, and -153 dissolved in safflower oil (18.7 microg total sigmaPBDEs/egg), approximating current levels in Great Lakes herring gulls. The measured proportions of BDE congeners found in the dosing oil were 56.4% of BDE-47; 27.2% of BDE-99; 24.8% of BDE-100; and 0.6% of BDE-153. For 29 days, nestlings were orally gavaged daily with the same sigmaPBDE mixture (15.6 +/- 0.3 ng/g body weight/day). Relative congener abundances in the dosing mixture compared to the carcasses suggest biotransformation of BDE-47; BDE-183 was also detected. PBDE exposure did not affect hatching or fledging success. PBDE-exposed nestlings were larger (weight, bones, feathers) as they gained weight more quickly and ate more food, the latter in association with their SigmaPBDE body burdens. BDE-100 was most influential on nestling growth, being positively associated with size, weight gain, and food consumption. Increasing concentrations of BDE-183 and -153 were related to longer bones, and BDE-99 to longer feathers. The larger size of the PBDE-exposed birds may be detrimental to their bone structure and have excessive energetic costs. The repeated relationships with BDE-100 and growth may be important for wild Falconidae, since this is the predominant penta-BDE congener in these raptors.

  12. Relevant role of efflux pumps in high levels of rifaximin resistance in Escherichia coli clinical isolates.

    PubMed

    Gomes, C; Ruiz, L; Pons, M J; Ochoa, T J; Ruiz, J

    2013-09-01

    Enteropathogens have shown a high level of resistance against commonly used antibacterial drugs in Peru and it is necessary to explore alternative treatments. The aim of this study was to analyse the in vitro activity of rifaximin against diarrhoeagenic and commensal Escherichia coli in children less than 2 years of age. The minimal inhibitory concentration (MIC) to rifampicin and rifaximin was determined for 210 strains in the presence and absence of phenyl-arginine-β-naphthylamide (PAβN) and the mechanisms of resistance were investigated. The MIC levels ranged between 8 and >256 mg/litre and the predominant mechanism of resistance to rifaximin was the efflux pumps inhibited by PAβN in 95.2% of the isolates. The present MIC values are higher than those observed in other studies. Efflux pumps inhibited by PAβN were the cause of the rifaximin resistance in the majority of cases and suggest the presence of an environmental selective pressure. Consequently, rifaximin should be used with caution in the treatment of diarrhoea in Peru.

  13. The effects of environmental enrichment on depressive- and anxiety-relevant behaviors in socially isolated prairie voles

    PubMed Central

    Grippo, Angela J.; Ihm, Elliott; Wardwell, Joshua; McNeal, Neal; Scotti, Melissa-Ann L.; Moenk, Deirdre A.; Chandler, Danielle L.; LaRocca, Meagan A.; Preihs, Kristin

    2014-01-01

    Objectives Social isolation is associated with depression, anxiety and negative health outcomes. Environmental enrichment, including environmental and cognitive stimulation with inanimate objects and opportunities for physical exercise, may be an effective strategy to include in treatment paradigms for affective disorders as a function of social isolation. In a rodent model – the socially monogamous prairie vole – we investigated the hypothesis that depression- and anxiety-related behaviors following social isolation would be prevented and remediated with environmental enrichment. Methods Experiment 1 investigated the preventive effects of environmental enrichment on negative affective behaviors when administered concurrently with social isolation. Experiment 2 investigated the remediating effects of enrichment on negative affective behaviors when administered following a period of isolation. Behaviors were measured in 3 operational tests: open field; forced swim test; and elevated plus maze. Results In isolated prairie voles, enrichment prevented depression- (immobility in FST, group × housing interaction, P=0.049) and anxiety-relevant behaviors (exploration in open field, group × housing interaction, P=0.036; exploration in elevated plus maze, group × housing interaction, P=0.049). Delayed enrichment also remediated these behaviors in isolated animals (immobility in forced swim test, main effect of housing, P=0.001; exploration in open field, main effect of housing, P=0.047; exploration in elevated plus maze, main effect of housing, P=0.001), and was slightly more effective than physical exercise alone in remediating anxiety-relevant behaviors. Conclusions These findings provide insight into the beneficial effects of an enriched environment on depression- and anxiety-relevant behaviors using a translational rodent model of social isolation. PMID:24804886

  14. NT-ProBNP Levels in Saliva and Its Clinical Relevance to Heart Failure

    PubMed Central

    Foo, Jared Yong Yang; Wan, Yunxia; Kostner, Karam; Arivalagan, Alicia; Atherton, John; Cooper-White, Justin; Dimeski, Goce; Punyadeera, Chamindie

    2012-01-01

    Background Current blood based diagnostic assays to detect heart failure (HF) have large intra-individual and inter-individual variations which have made it difficult to determine whether the changes in the analyte levels reflect an actual change in disease activity. Human saliva mirrors the body’s health and well being and ∼20% of proteins that are present in blood are also found in saliva. Saliva has numerous advantages over blood as a diagnostic fluid which allows for a non-invasive, simple, and safe sample collection. The aim of our study was to develop an immunoassay to detect NT-proBNP in saliva and to determine if there is a correlation with blood levels. Methods Saliva samples were collected from healthy volunteers (n = 40) who had no underlying heart conditions and HF patients (n = 45) at rest. Samples were stored at −80°C until analysis. A customised homogeneous sandwich AlphaLISA(R) immunoassay was used to quantify NT-proBNP levels in saliva. Results Our NT-proBNP immunoassay was validated against a commercial Roche assay on plasma samples collected from HF patients (n = 37) and the correlation was r2 = 0.78 (p<0.01, y = 1.705× +1910.8). The median salivary NT-proBNP levels in the healthy and HF participants were <16 pg/mL and 76.8 pg/mL, respectively. The salivary NT-proBNP immunoassay showed a clinical sensitivity of 82.2% and specificity of 100%, positive predictive value of 100% and negative predictive value of 83.3%, with an overall diagnostic accuracy of 90.6%. Conclusion We have firstly demonstrated that NT-proBNP can be detected in saliva and that the levels were higher in heart failure patients compared with healthy control subjects. Further studies will be needed to demonstrate the clinical relevance of salivary NT-proBNP in unselected, previously undiagnosed populations. PMID:23119023

  15. Dosimetric analysis of fathead minnow (Pimephales promelas, Rafinesque, 1820) exposed via ingestion to environmentally relevant activities of Ra-226 for two years.

    PubMed

    Mothersill, Carmel; Larivière, Dominic; Smith, Richard W; Thompson, Manuela P; Byun, Soo H; Prestwich, William; Seymour, Colin B

    2014-02-01

    To assess the dosimetry of Ra-226 in a two-year chronic ingestion study in laboratory maintained fathead minnow fed environmentally relevant levels of the isotope known to occur in gut contents of fish from a uranium mining area. Fish were established on reconstituted commercial fish food containing 10 mBq-10 Bq Ra-226.g(- 1) dry food. The fish were sampled at 1, 6, 18 and 24 months and the Ra-226 levels in the whole fish were directly determined using measurement performed using inorganic mass spectrometry. Pilot experiments using higher doses were also done during development of a liquid scintillation detection system which support some data. The data show that after 1 month the levels of accumulation in the fish were below detection. At 6 months there was an activity dependent accumulation which was relatively higher in the low activity groups. By 18 and 24 months the radium was very low in all groups - well below 6 month levels suggesting considerable loss of radium from the fish. These data were confirmed in a small and shorter study using higher dietary activities. The highest dose calculated for any measurement point was 16 μGy.h(- 1) in the 6-month-old fish fed the diet containing 10 Bq.g(- 1). We conclude that environmentally relevant levels of Ra-226 have a maximum impact at early time-points when the fish are still growing. After that they appear to depurate accumulated radium. In terms of environmental impact, the maximum accumulation peaks at the age where fish could be spawning but is extremely low leading to μGy.year(- 1) doses even after exposure to the high activity diets.

  16. Inter-Neighborhood Migration, Race, and Environmental Hazards: Modeling Micro-Level Processes of Environmental Inequality

    PubMed Central

    Crowder, Kyle; Downey, Liam

    2009-01-01

    This study combines data from the Panel Study of Income Dynamics with neighborhood-level industrial hazard data from the Environmental Protection Agency to examine the extent and sources of environmental inequality at the individual level. Results indicate that profound racial and ethnic differences in proximity to industrial pollution persist when differences in individual education, household income, and other micro-level characteristics are controlled. Examination of underlying migration patterns further reveals that black and Latino householders move into neighborhoods with significantly higher hazard levels than do comparable whites, and that racial differences in proximity to neighborhood pollution are maintained more by these disparate mobility destinations than by differential effects of pollution on the decision to move. PMID:20503918

  17. Genes, epigenetic regulation and environmental factors: which is the most relevant in developing autoimmune diseases?

    PubMed

    Costenbader, Karen H; Gay, Steffen; Alarcón-Riquelme, Marta E; Iaccarino, Luca; Doria, Andrea

    2012-06-01

    Autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis and inflammatory bowel disease, have complex pathogeneses and likely multifactorial etiologies. The current paradigm for understanding their development is that the disease is triggered in genetically-susceptible individuals by exposure to environmental factors. Some of these environmental factors have been specifically identified, while others are hypothesized and not yet proven, and it is likely that most have yet to be identified. One interesting hypothesis is that environmental effects on immune responses could be mediated by changes in epigenetic regulation. Major mechanisms of epigenetic gene regulation include DNA methylation and histone modification. In these cases, gene expression is modified without involving changes in DNA sequence. Epigenetics is a new and interesting research field in autoimmune diseases. We review the roles of genetic factors, epigenetic regulation and the most studied environmental risk factors such as cigarette smoke, crystalline silica, Epstein-Barr virus, and reproductive hormones in the pathogenesis of autoimmune disease. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Effects of Environmentally Relevant Concentrations of Bisphenol A on the Fathead Minnow

    EPA Science Inventory

    Bisphenol A (BPA) is a wide-spread environmental contaminant of concern due, in part, to possible effects on the vertebrate hypothalamic-pituitary-gonadal (HPG) axis, including activation of the estrogen receptor (ER). There is a reasonable amount of toxicological information fo...

  19. Environmental issues relevant to the preparation of USAID/Mozambique`s country program strategic plan

    SciTech Connect

    1994-01-01

    The present moment offers a unique opportunity to address Mozambique`s environmental problems, according to this assessment of Mozambique`s natural and environmental resources. Conducted to help USAID/M prepare its Country Program Strategic Plan (CPSP), the assessment covers: (1) the status of Mozambique`s natural resources (soil and land, water, vegetative cover, wildlife/biodiversity and nonrenewable resources), with emphasis on conservation and management of biological diversity and tropical forests; (2) shortcomings in the knowledge and management of these resources; (3) the efforts of other donors and NGOs to address natural resources degradation; and (4) recommendations. According to the report, while all three of the CPSP`s focus areas -- income generation, social services, the democratic governance -- can contribute notably to sustainable use of the environment, the income focus will have the most impact, as families who are struggling to survive often turn to destructive patterns of land use. The report cautions USAID/M not to neglect, in its emphasis on NGOs, the state agencies that will be responsible for guaranteeing security in areas such as land rights. In particular, the Mission should promote the policymaking and enforcement role of the National Commission for the Environment (CNA) and should involve the CNA in Mission environmental assessments. Appendices include a summary of donor environmental activities in Mozambique; a tabulated portrait of Mozambique`s forest resources and forestry sector; and a list of state agencies with responsibilities in Mozambique`s coastal zone.

  20. A Selected Bibliography on the Relevance of Environmental Education to Secondary School Curricula.

    ERIC Educational Resources Information Center

    Cunningham, Michael C., Comp.; Cunningham, Cheryl Bond, Comp.

    The intent of this bibliography is to provide resources for the secondary school teacher concerning (1) substantive information about the environment and (2) means and methods of communicating that information in the classroom. It deals primarily with the man-made environment rather than with environmental resources and has an urban bias - not one…

  1. A Culturally Relevant Agricultural and Environmental Course for K-12 Teachers in Hawaii

    ERIC Educational Resources Information Center

    Sylva, Traci; Chinn, Pauline; Kinoshita, Charles

    2010-01-01

    A Hawaiian cultural-based agricultural and environmental science professional development course was transformed based on the precepts of situated learning in communities of practice, and offered to K-12 teachers. In this article we describe the format and content of the transformed course based on lessons learned from previous years offered to…

  2. Roles of Heat Shock Factor 1 in neuronal response to fetal environmental risks and its relevance to brain disorders

    PubMed Central

    Hashimoto-Torii, Kazue; Torii, Masaaki; Fujimoto, Mitsuaki; Nakai, Akira; Fatimy, Rachid El; Mezger, Valerie; Ju, Min J.; Ishii, Seiji; Chao, Shih-hui; Brennand, Kristen J; Gage, Fred H; Rakic, Pasko

    2014-01-01

    Prenatal exposure of the developing brain to various environmental challenges increases susceptibility to late-onset of neuropsychiatric dysfunction; still the underlying mechanisms remain obscure. Here we show that exposure of embryos to a variety of environmental factors such as alcohol, methylmercury and maternal seizure activates HSF1 in cerebral cortical cells. Furthermore, Hsf1 deficiency in the mouse cortex exposed in utero to subthreshold levels of these challenges causes structural abnormalities and increases seizure susceptibility after birth. In addition, we found that human neural progenitor cells differentiated from induced pluripotent stem cells derived from schizophrenia patients show higher variability in the levels of HSF1 activation induced by environmental challenges compared to controls. We propose that HSF1 plays a crucial role in the response of brain cells to prenatal environmental insults and may be a key component in the pathogenesis of late–onset neuropsychiatric disorders. PMID:24726381

  3. County-level environmental quality and associations with cancer incidence#

    EPA Science Inventory

    Background: Cancer risk is affected by a combination of behavioral, genetic, and environmental factors. Individual environmental exposures have been associated with cancer development; however, a variety of environmental exposures may occur simultaneously. The Environmental Quali...

  4. Isotopes in geobiochemistry: tracing metabolic pathways in microorganisms of environmental relevance with stable isotopes.

    PubMed

    Adrian, Lorenz; Marco-Urrea, Ernest

    2016-10-01

    Stable isotopes are flexibly used as tracers to investigate environmental processes, microorganisms responsible for environmental transformations, syntrophic relationships in consortia, and metabolic pathways. With the advent of widely accessible high-resolution, highly accurate and sensitive mass spectrometers connected to liquid chromatography (LC-MS/MS) and the explosion of microbial genome sequence information the options to apply stable isotope tracers to geobiochemical topics have multiplied. With methods at hand to analyze biochemical pathways and enzymatic functions of yet-uncultivated microorganisms even in mixed cultures, a wide field of new discoveries can be expected. Applications rely both on the high sensitivity to detect trace amounts of biological material in slow or non-growing cultures and on the high multi-dimensional resolution of LC-MS/MS to allow the separation of complex samples and to retrieve phylogenetic information. Challenges and examples of stable isotope applications to describe geobiochemical processes are reviewed. Overall, the potential is not yet sufficiently deployed.

  5. Relevance of lipopolysaccharide levels in HIV-associated neurocognitive impairment: the Neuradapt study.

    PubMed

    Vassallo, Matteo; Dunais, Brigitte; Durant, Jacques; Carsenti-Dellamonica, Helene; Harvey-Langton, Alexandra; Cottalorda, Jacqueline; Ticchioni, Michel; Laffon, Muriel; Lebrun-Frenay, Christine; Dellamonica, Pierre; Pradier, Christian

    2013-08-01

    Contributory factors to HIV-associated neurocognitive disorders (HAND) have been shown to include age, co-morbid infections, medication toxicity, virological, genetic and vascular mechanisms, as well as microbial translocation of lipopolysaccharide (LPS), which is suspected to trigger monocyte activation and increase trafficking of infected cells into the brain. In this study, our aim was to assess the degree of neurocognitive impairment in a group of randomly selected HIV-infected patients and investigate potential risk factors, including LPS plasma levels. Furthermore, we evaluated the relevance of LPS as a potential marker for screening patients with mild neurocognitive impairment. LPS plasma levels were compared among patients with HAND and those with no HAND. As LPS has also been shown to be elevated in hepatitis C co-infection, the analysis was stratified according to the presence or not of hepatitis C virus (HCV) co-infection. Differences between groups were evaluated using chi-square tests and Kruskal-Wallis non-parametric tests. Stepwise logistic regression was performed to identify independent risk factors for HAND in the subgroups of HCV-positive and negative patients. A p value <0.05 was considered significant. Analyses were conducted using SPSS® software. From December 2007 to July 2009, 179 patients were tested (mean age 44, 73 % male, 87 % on treatment, 30 % HCV co-infected, median CD4 504/ml and 67 % with viral load below 40 copies/ml). HAND was identified in 40/179 patients (22 %), the majority displaying asymptomatic neurocognitive impairment or mild neurocognitive disorder. Univariate analysis showed that age, illicit drug use, hepatitis C co-infection, prior AIDS-defining events, CD4/CD8 ratio and LPS plasma levels were significantly associated with HAND. The median LPS level was 98.2 pg/ml in the non-HAND group versus 116.1 pg/ml in the HAND group (p < 0.014). No differences were found in LPS values between subgroups of impairment. There was a

  6. A Response to Scott's Concerns about the Relevance of Environmental Education Research: Applying Social-Ecological Systems Thinking and Consilience to Defining Research Goals

    ERIC Educational Resources Information Center

    Krasny, Marianne E.

    2009-01-01

    In William Scott's plenary address at the World Environmental Education Conference, he expressed concerns about the relevance of environmental education research in a world facing global environmental and demographic change. In responding to Scott's concerns, I argue that addressing challenges related to development and the environment requires…

  7. A Response to Scott's Concerns about the Relevance of Environmental Education Research: Applying Social-Ecological Systems Thinking and Consilience to Defining Research Goals

    ERIC Educational Resources Information Center

    Krasny, Marianne E.

    2009-01-01

    In William Scott's plenary address at the World Environmental Education Conference, he expressed concerns about the relevance of environmental education research in a world facing global environmental and demographic change. In responding to Scott's concerns, I argue that addressing challenges related to development and the environment requires…

  8. Environmental monitoring of low-level radioactive waste disposal facility

    SciTech Connect

    Shum, E.Y.; Starmer, R.J.; Young, M.H.

    1989-12-01

    This branch technical position (BTP) paper on the environmental monitoring program for a low-level radioactive waste disposal facility provides general guidance on what is required by Section 61.53 of Title 10 of the Code of Federal Regulations (10 CFR) of applicants submitting a license application for such a facility. In general, the environmental monitoring program consists of three phases: preoperational, operational, and postoperational. Each phase of the monitoring program should be designed to fulfill the specific objectives defined in the BTP paper. During the preoperational phase, the objectives of the program are to provide site characterization information, to demonstrate site suitability and acceptability, to obtain background or baseline information, and to provide a record for public information. During the operational phase, the emphasis on measurement shifts. Monitoring data are obtained to provide early warning of releases and to document compliance with regulations, the dose limits of 10 CFR Part 61, or applicable standards of the US Environmental Protection Agency. Data are also used to update important pathway parameters to improve predictions of site performance and to provide a record of performance for public information. The postoperational environmental monitoring program emphasizes measurements to demonstrate compliance with the site-closure requirements and continued compliance with the performance objective in regard to the release of radionuclides to the environment. The data are used to support evaluation of long-term effects on the general public and for public information. Guidance is also provided in the BTP paper on the choice of which constituents to measure, setting action levels, relating measurements to appropriate actions in a corrective action plan, and quality assurance.

  9. Effects of dissolved organic matter (DOM) at environmentally relevant carbon concentrations on atrazine degradation by Chelatobacter heintzii SalB.

    PubMed

    Cheyns, Karlien; Calcoen, Jasper; Martin-Laurent, Fabrice; Bru, David; Smolders, Erik; Springael, Dirk

    2012-09-01

    The dissolved organic matter (DOM) is the term used for organic components of natural origin present in the soil solution and is probably the most available C-source that primes microbial activity in subsoils. Contrasting effects of organic C components on pesticide degradation have been reported; however, most studies have used model organic compounds with compositions and concentrations which differ substantially from those found in the environment. Degradation of atrazine (AT) by Chelatobacter heintzii SalB was monitored in liquid batch assays in the absence or presence of well-defined model C compounds (glucose, gluconate and citrate) as model DOM (mDOM) or complex, less-defined, environmental DOM solutions (eDOM: isolated humic substances, soil and plant residue extracts) at environmentally relevant concentrations. Glucose significantly increased AT degradation rate by more than a factor of 8 at and above 2.5 mg C L( - 1). Optical density measurements showed that this stimulation is related to microbial growth. Gluconate and citrate had no effects unless at non-relevant concentrations (1,000 mg DOC L( - 1)) at which stimulations (gluconate) or inhibitions (citrate) were found. The effects of eDOM added at 10 mg DOC L( - 1) on AT degradation were generally small. The AT degradation time was reduced by factors 1.4-1.9 in the presence of humic acids and eDOM from soils amended with plant residues; however, no effects were found for fulvic acids or eDOM from a soil leachate solution or extracted from unamended peat or forest soil. In conclusion, DOM supplied as both mDOM and eDOM did not inhibit AT degradation at environmentally relevant concentrations, and stimulation can be found for selected DOM samples and this is partly related to its effect on growth.

  10. Low impact of exposure to environmentally relevant doses of 226Ra in Atlantic cod (Gadus morhua) embryonic cells.

    PubMed

    Olsvik, Pål A; Berntssen, Marc H G; Hylland, Ketil; Eriksen, Dag Ø; Holen, Elisabeth

    2012-07-01

    The aim of this study was to investigate whether (226)Ra, a radionuclide present in produced water from oil platforms in the North Sea and other offshore drilling areas, could affect vulnerable early life stages of Atlantic cod (Gadus morhua). Blastula-stage embryonic cells (EC) from fertilized eggs of Atlantic cod were isolated and exposed to environmental relevant concentrations of (226)Ra and transcription of selected genes quantified. The results showed a weak, but significant up-regulation of GPx3 and HSP70 transcripts after 48 h of exposure to 2.11 Bq/L. In EC exposed to three (226)Ra concentrations (2.11, 23 and 117 Bq/L) for 12 h, metallothionein, HSP90AA, thioredoxin and caspase 8 were significantly up-regulated in cells exposed to 117 Bq/L, whereas thioredoxin was also significantly up-regulated in EC exposed to 23 Bq/L. When EC were exposed to the same (226)Ra concentrations for 48 h, only heme oxygenase was significantly up-regulated in the 23 Bq/L exposure group. The results suggest that environmentally relevant activities of (226)Ra may induce oxidative stress and apoptosis in fish ECs. Exposure of Atlantic cod EC to Cd, selected as a model toxicant, supported the ability of EC around blastula stage to respond to toxicants by altered transcription. Due to dilution, environmentally relevant concentrations of radionuclides present in produced water would be expected to pose a minor threat to early life stages of fish. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance. Environmental Restoration Program

    SciTech Connect

    Etnier, E.L.; Eaton, L.A.

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms ``applicable`` and ``relevant and appropriate`` is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed.

  12. Environmental tobacco smoke and canine urinary cotinine level

    SciTech Connect

    Bertone-Johnson, Elizabeth R. Procter-Gray, Elizabeth; Gollenberg, Audra L.; Ryan, Michele B.; Barber, Lisa G.

    2008-03-15

    Epidemiologic studies of companion animals such as dogs have been established as models for the relationship between exposure to environmental tobacco smoke (ETS) and cancer risk in humans. While results from these studies are provocative, pet owner report of a dog's ETS exposure has not yet been validated. We have evaluated the relationship between dog owner's report of household smoking by questionnaire and dog's urinary cotinine level. Between January and October 2005, dog owners presenting their pet for non-emergency veterinary care at the Foster Hospital for Small Animals at Cummings School of Veterinary Medicine, Tufts University, were asked to complete a 10-page questionnaire measuring exposure to household ETS in the previous 24 h and other factors. A free-catch urine sample was also collected from dogs. Urinary cotinine level was assayed for 63 dogs, including 30 whose owners reported household smoking and 33 unexposed dogs matched on age and month of enrollment. Urinary cotinine level was significantly higher in dogs exposed to household smoking in the 24 h before urine collection compared to unexposed dogs (14.6 ng/ml vs. 7.4 ng/ml; P=0.02). After adjustment for other factors, cotinine level increased linearly with number of cigarettes smoked by all household members (P=0.004). Other canine characteristics including age, body composition and nose length were also associated with cotinine level. Findings from our study suggest that household smoking levels as assessed by questionnaire are significantly associated with canine cotinine levels.

  13. Characterizing photochemical transformation of aqueous nC60 under environmentally relevant conditions.

    PubMed

    Hwang, Yu Sik; Li, Qilin

    2010-04-15

    Engineered nanomaterials may undergo transformation upon interactions with various environmental factors. In this study, photochemical transformation of aqueous nC60 was investigated under UVA irradiation. nC60 underwent photochemical transformation in the presence of dissolved O2, resulting in surface oxygenation and hydroxylation as demonstrated by XPS and ATR-FTIR analyses. The reaction followed a pseudo-first order rate law with the apparent reaction rate constant of 2.2 x 10(-2) h(-1). However, the core of the nanoparticles remained intact over 21 days of irradiation. Although no mineralization or dissolution of nC60 was observed, experiments using fullerol as a reference fullerene derivative suggested likely dissolution and partial mineralization of nC60 under long-term UVA exposure. Aquatic humic acid reduced nC60 transformation kinetics presumably due to scavenging of reactive oxygen species. Results from this study imply that photochemical transformation is an important factor controlling nC60 physical and chemical properties as well as its fate and transport in the natural aqueous environment. In addition, changes in nC60 surface chemistry drastically reduced C60 extraction efficiency by toluene, suggesting that the existing analytical method for C60 may not be applicable to environmental samples.

  14. Using Magnetically Responsive Tea Waste to Remove Lead in Waters under Environmentally Relevant Conditions

    PubMed Central

    Yeo, Siang Yee; Choi, Siwon; Dien, Vivian; Sow-Peh, Yoke Keow; Qi, Genggeng; Hatton, T. Alan; Doyle, Patrick S.; Thio, Beng Joo Reginald

    2013-01-01

    We report the use of a simple yet highly effective magnetite-waste tea composite to remove lead(II) (Pb2+) ions from water. Magnetite-waste tea composites were dispersed in four different types of water–deionized (DI), artificial rainwater, artificial groundwater and artificial freshwater–that mimic actual environmental conditions. The water samples had varying initial concentrations (0.16–5.55 ppm) of Pb2+ ions and were mixed with the magnetite-waste tea composite for at least 24 hours to allow adsorption of the Pb2+ ions to reach equilibrium. The magnetite-waste tea composites were stable in all the water samples for at least 3 months and could be easily removed from the aqueous media via the use of permanent magnets. We detected no significant leaching of iron (Fe) ions into the water from the magnetite-waste tea composites. The percentage of Pb adsorbed onto the magnetite-waste tea composite ranged from ∼70% to 100%; the composites were as effective as activated carbon (AC) in removing the Pb2+ ions from water, depending on the initial Pb concentration. Our prepared magnetite-waste tea composites show promise as a green, inexpensive and highly effective sorbent for removal of Pb in water under environmentally realistic conditions. PMID:23818955

  15. Using magnetically responsive tea waste to remove lead in waters under environmentally relevant conditions.

    PubMed

    Yeo, Siang Yee; Choi, Siwon; Dien, Vivian; Sow-Peh, Yoke Keow; Qi, Genggeng; Hatton, T Alan; Doyle, Patrick S; Thio, Beng Joo Reginald

    2013-01-01

    We report the use of a simple yet highly effective magnetite-waste tea composite to remove lead(II) (Pb(2+)) ions from water. Magnetite-waste tea composites were dispersed in four different types of water-deionized (DI), artificial rainwater, artificial groundwater and artificial freshwater-that mimic actual environmental conditions. The water samples had varying initial concentrations (0.16-5.55 ppm) of Pb(2+) ions and were mixed with the magnetite-waste tea composite for at least 24 hours to allow adsorption of the Pb(2+) ions to reach equilibrium. The magnetite-waste tea composites were stable in all the water samples for at least 3 months and could be easily removed from the aqueous media via the use of permanent magnets. We detected no significant leaching of iron (Fe) ions into the water from the magnetite-waste tea composites. The percentage of Pb adsorbed onto the magnetite-waste tea composite ranged from ∼70% to 100%; the composites were as effective as activated carbon (AC) in removing the Pb(2+) ions from water, depending on the initial Pb concentration. Our prepared magnetite-waste tea composites show promise as a green, inexpensive and highly effective sorbent for removal of Pb in water under environmentally realistic conditions.

  16. Glucocorticoid activity detected by in vivo zebrafish assay and in vitro glucocorticoid receptor bioassay at environmental relevant concentrations.

    PubMed

    Chen, Qiyu; Jia, Ai; Snyder, Shane A; Gong, Zhiyuan; Lam, Siew Hong

    2016-02-01

    Glucocorticoids are pharmaceutical contaminants of emerging concern due to their incomplete removal during wastewater treatment, increased presence in aquatic environment and their biological potency. The zebrafish is a popular model for aquatic toxicology and environmental risk assessment. This study aimed to determine if glucocorticoids at environmental concentrations would perturb expression of selected glucocorticoid-responsive genes in zebrafish and to investigate their potentials as an in vivo zebrafish assay in complementing in vitro glucocorticoid receptor bioassay. The relative expression of eleven glucocorticoid-responsive genes in zebrafish larvae and liver of adult male zebrafish exposed to three representative glucocorticoids (dexamethasone, prednisolone and triamcinolone) was determined. The expression of pepck, baiap2 and pxr was up-regulated in zebrafish larvae and the expression of baiap2, pxr and mmp-2 was up-regulated in adult zebrafish exposed to glucocorticoids at concentrations equivalent to total glucocorticoids reported in environmental samples. The responsiveness of the specific genes were sufficiently robust in zebrafish larvae exposed to a complex environmental sample detected with in vitro glucocorticoid activity equivalent to 478 pM dexamethasone (DEX-EQ) and confirmed to contain low concentration (0.2 ng/L or less) of the targeted glucocorticoids, and possibly other glucocorticoid-active compounds. The findings provided in vivo relevance to the in vitro glucocorticoid activity and suggested that the environmental sample can perturb glucocorticoid-responsive genes in its original, or half the diluted, concentration as may be found in the environment. The study demonstrated the important complementary roles of in vivo zebrafish and in vitro bioassays coupled with analytical chemistry in monitoring environmental glucocorticoid contaminants.

  17. Target-Specific Capture of Environmentally Relevant Gaseous Aldehydes and Carboxylic Acids with Functional Nanoparticles.

    PubMed

    Campbell, McKenzie L; Guerra, Fernanda D; Dhulekar, Jhilmil; Alexis, Frank; Whitehead, Daniel C

    2015-10-12

    Aldehyde and carboxylic acid volatile organic compounds (VOCs) present significant environmental concern due to their prevalence in the atmosphere. We developed biodegradable functional nanoparticles comprised of poly(d,l-lactic acid)-poly(ethylene glycol)-poly(ethyleneimine) (PDLLA-PEG-PEI) block co-polymers that capture these VOCs by chemical reaction. Polymeric nanoparticles (NPs) preparation involved nanoprecipitation and surface functionalization with branched PEI. The PDLLA-PEG-PEI NPs were characterized by using TGA, IR, (1) H NMR, elemental analysis, and TEM. The materials feature 1°, 2°, and 3° amines on their surface, capable of capturing aldehydes and carboxylic acids from gaseous mixtures. Aldehydes were captured by a condensation reaction forming imines, whereas carboxylic acids were captured by acid/base reaction. These materials reacted selectively with target contaminants obviating off-target binding when challenged by other VOCs with orthogonal reactivity. The NPs outperformed conventional activated carbon sorbents.

  18. Supramolecular chemistry of selective anion recognition for anions of environmental relevance. 1998 annual progress report

    SciTech Connect

    Bowman-James, K.; Wilson, G.S.; Kuczera, K.; Moyer, B.

    1998-06-01

    'This project has as its focus the design and synthesis of polyammonium macrocyclic receptors for oxoanions of environmental importance. The basic research aspects of this project involve: (1) synthesis (and the search for improved synthetic methods); (2) solid state structure determination and thermodynamics studies (to ascertain structural criteria for and strength of anion binding); and (3) molecular dynamics simulations (to assess solution characteristics of the interactions between anions and their receptors). Applications-oriented goals include the fabrication of more selective anion-selective electrodes and the use of these compounds in liquid-liquid separations. The latter goal comprises the subcontract with Dr. Bruce Moyer at Oak Ridge National Laboratory. This report summarizes work after 1 year and 7 months of a 3-year project. To date, the authors have focussed on the design and synthesis of selective receptors for nitrate and phosphate.'

  19. Isotopically modified silver nanoparticles to assess nanosilver bioavailability and toxicity at environmentally relevant exposures

    USGS Publications Warehouse

    Croteau, Marie-Noële; Dybowska, Agnieszka D.; Luoma, Samuel N.; Misra, Superb K.; Valsami-Jones, Eugenia

    2014-01-01

    A major challenge in understanding the environmental implications of nanotechnology lies in studying nanoparticle uptake in organisms at environmentally realistic exposure concentrations. Typically, high exposure concentrations are needed to trigger measurable effects and to detect accumulation above background. But application of tracer techniques can overcome these limitations. Here we synthesised, for the first time, citrate-coated Ag nanoparticles using Ag that was 99.7 % 109Ag. In addition to conducting reactivity and dissolution studies, we assessed the bioavailability and toxicity of these isotopically modified Ag nanoparticles (109Ag NPs) to a freshwater snail under conditions typical of nature. We showed that accumulation of 109Ag from 109Ag NPs is detectable in the tissues of Lymnaea stagnalis after 24-h exposure to aqueous concentrations as low as 6 ng L–1 as well as after 3 h of dietary exposure to concentrations as low as 0.07 μg g–1. Silver uptake from unlabelled Ag NPs would not have been detected under similar exposure conditions. Uptake rates of 109Ag from 109Ag NPs mixed with food or dispersed in water were largely linear over a wide range of concentrations. Particle dissolution was most important at low waterborne concentrations. We estimated that 70 % of the bioaccumulated 109Ag concentration in L. stagnalis at exposures –1 originated from the newly solubilised Ag. Above this concentration, we predicted that 80 % of the bioaccumulated 109Ag concentration originated from the 109Ag NPs. It was not clear if agglomeration had a major influence on uptake rates.

  20. Applicable or Relevant and Appropriate Requirements (ARARs) for Remedial Action at the Oak Ridge Reservation: A compendium of major environmental laws. Environmental Restoration Program

    SciTech Connect

    Etnier, E.L.; McDonald, E.P.; Houlberg, L.M.

    1993-07-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances must comply with applicable or relevant and appropriate requirements (ARARS) or standards under federal and state environmental laws. The US Department of Energy (DOE) Oak Ridge Reservation (ORR) was placed on the National Priorities List by the US Environmental Protection Agency (EPA) on November 21, 1989, effective December 21, 1989. As a result of this listing, DOE, EPA, and the Tennessee Department of Environment and Conservation have signed a Federal Facility Agreement (FFA) for the environmental restoration of the ORR. Section XXI(F) of the FFA calls for the preparation of a draft listing of all ARARs as mandated by CERCLA {section}121. This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at the ORR. A description of the terms ``applicable`` and ``relevant and appropriate`` is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Tennessee are listed in tables. In addition, the major provisions of the Resource Conservation and Recovery Act, the Safe Drinking Water Act, the Clean Water Act, the Clean Air and other acts, as they apply to hazardous waste cleanup, are discussed. In the absence of ARARS, CERCLA {section}121 provides for the use of nonpromulgated federal criteria, guidelines, and advisories in evaluating the human risk associated with remedial action alternatives. Such nonpromulgated standards are classified as ``to-be-considered`` (TBC) guidance. A ion of available guidance is given; summary tables fist the available federal standards and guidance information. In addition, the substantive contents of the DOE orders as they apply to remediation of radioactively contaminated sites are discussed as TBC guidance.

  1. Chronic toxicity of an environmentally relevant mixture of pharmaceuticals to three aquatic organisms (alga, daphnid, and fish).

    PubMed

    Watanabe, Haruna; Tamura, Ikumi; Abe, Ryoko; Takanobu, Hitomi; Nakamura, Ataru; Suzuki, Toshinari; Hirose, Akihiko; Nishimura, Tetsuji; Tatarazako, Norihisa

    2016-04-01

    Principles of concentration addition and independent action have been used as effective tools to predict mixture toxicity based on individual component toxicity. The authors investigated the toxicity of a pharmaceutical mixture composed of the top 10 detected active pharmaceutical ingredients (APIs) in the Tama River (Tokyo, Japan) in a relevant concentration ratio. Both individual and mixture toxicities of the 10 APIs were evaluated by 3 short-term chronic toxicity tests using the alga Pseudokirchneriella subcapitata, the daphnid Ceriodaphnia dubia, and the zebrafish Danio rerio. With the exception of clarithromycin toxicity to alga, the no-observed-effect concentration of individual APIs for each test species was dramatically higher than the highest concentration of APIs found in the environment. The mixture of 10 APIs resulted in toxicity to alga, daphnid, and fish at 6.25 times, 100 times, and 15,000 times higher concentrations, respectively, than the environmental concentrations of individual APIs. Predictions by concentration addition and independent action were nearly identical for alga, as clarithromycin was the predominant toxicant in the mixture. Both predictions described the observed mixture toxicity to alga fairly well, whereas they slightly underestimated the observed mixture toxicity in the daphnid test. In the fish embryo test, the observed toxicity fell between the predicted toxicity by concentration addition and independent action. These results suggested that the toxicity of environmentally relevant pharmaceutical mixtures could be predicted by individual toxicity using either concentration addition or independent action. © 2015 SETAC.

  2. Effects of environmentally-relevant mixtures of four common organophosphorus insecticides on the honey bee (Apis mellifera L.).

    PubMed

    Al Naggar, Yahya; Wiseman, Steve; Sun, Jianxian; Cutler, G Christopher; Aboul-Soud, Mourad; Naiem, Elsaied; Mona, Mohamed; Seif, Amal; Giesy, John P

    2015-11-01

    We assessed whether exposure to environmentally-relevant mixtures of four organophosphorus insecticides (OPs) exerted adverse effects on honey bees. Adult and worker bees were orally exposed for five days under laboratory conditions to mixtures of four insecticides, diazinon, malathion, profenofos and chlorpyrifos at two concentrations. Concentration in the mixtures tested were equivalent to the median and 95th centile concentrations of the OPs in honey, as reported in the literature. Effects on survival, behavior, activity of acetylcholinesterase (AChE), and expression of genes important in detoxification of xenobiotics and immune response were examined. Survival of worker bees was not affected by exposure to median or 95th centile concentrations of the OPs. Activity of AChE was significantly greater in worker bees exposed to the 95th centile concentration mixture of OPs compared to the median concentration mixture. Expression of genes involved in detoxification of xenobiotics was not affected by treatment, but the abundance of transcripts of the antimicrobial peptide hymenoptaecin was significantly greater in worker honey bees exposed to the median concentration mixture. Results suggest that short-term exposure to environmentally relevant concentrations of a mixture of OPs do not adversely affect worker honey bees.

  3. Ecologically relevant geomorphic attributes of streams are impaired by even low levels of watershed effective imperviousness

    NASA Astrophysics Data System (ADS)

    Vietz, Geoff J.; Sammonds, Michael J.; Walsh, Christopher J.; Fletcher, Tim D.; Rutherfurd, Ian D.; Stewardson, Michael J.

    2014-02-01

    Urbanization almost inevitably results in changes to stream morphology. Understanding the mechanisms for such impacts is a prerequisite to minimizing stream degradation and achieving restoration goals. However, investigations of urban-induced changes to stream morphology typically use indicators of watershed urbanization that may not adequately represent degrading mechanisms and commonly focus on geomorphic attributes such as channel dimensions that may be of little significance to the ecological goals for restoration. We address these shortcomings by testing if a measure characterizing urban stormwater drainage system connections to streams (effective imperviousness, EI) is a better predictor of change to ecologically relevant geomorphic attributes than a more general measure of urban density (total imperviousness, TI). We test this for 17 sites in independent watersheds across a gradient of urbanization. We found that EI was a better predictor of all geomorphic variables tested than was TI. Bank instability was positively correlated with EI, while width/depth (a measure of channel incision), bedload sediment depth, and frequency of bars, benches, and large wood were negatively correlated. Large changes in all geomorphic variables were detected at very low levels of EI (< 2-3%). Excess urban stormwater runoff, as represented by EI, drives geomorphic change in urban streams, highlighting the dominant role of the stormwater drainage system in efficiently transferring stormwater runoff from impervious surfaces to the stream, as found for ecological indicators. It is likely that geomorphic condition of streams in urbanizing watersheds, particularly those attributes of ecological relevance, can only be maintained if excess urban stormwater flows are kept out of streams through retention and harvesting. The extent to which EI can be reduced within urban and urbanizing watersheds, through techniques such as distributed stormwater harvesting and infiltration, and the

  4. Primary hepatocytes from Arctic char (Salvelinus alpinus) as a relevant Arctic in vitro model for screening contaminants and environmental extracts.

    PubMed

    Petersen, Karina; Hultman, Maria T; Tollefsen, Knut Erik

    2017-06-01

    Contaminants find their way to the Arctic through long-range atmospheric transport, transport via ocean currents, and through increased anthropogenic activity. Some of the typical pollutants reaching the Arctic (PAHs, PCBs) are known to induce cytochrome P450 1a (CYP1A) protein expression and ethoxyresorufin-O-deethylase (EROD) activity through the aryl hydrocarbon receptor (AhR). In addition, some endocrine disrupting chemicals (EDCs) such as estrogen mimics (xenoestrogens) have been documented in Arctic areas and they may interfere with natural sexual development and reproduction. In vitro assays that are capable of detecting effects of such pollutants, covering multiple endpoints, are generally based on mammalian or temperate species and there are currently no well-characterized cell-based in vitro assays for effect assessment from Arctic fish species. The present study aimed to develop a high-throughput and multi-endpoint in vitro assay from Arctic char (Salvelinus alpinus) to provide a non-animal (alternative) testing method for an ecologically relevant Arctic species. A method for isolation and exposure of primary hepatocytes from Arctic char for studying the toxic effects and mode of action (MoA) of pollutants was applied and validated. The multi-versatility of the bioassay was assessed by classical biomarker responses such as cell viability (membrane integrity and metabolic activity), phase I detoxification (CYP1A protein expression, EROD activity) and estrogen receptor (ER) mediated vitellogenin (Vtg) protein expression using a selection of model compounds, environmental pollutants and an environmental extract containing a complex mixture of pollutants. Primary hepatocytes from Arctic char were successfully isolated and culture conditions optimized to identify the most optimal assay conditions for covering multiple endpoints. The hepatocytes responded with concentration-dependent responses to all of the model compounds, most of the environmental pollutants

  5. The Ivory Tower and the Community: A New Approach to Emphasizing the Relevance of Environmental Science Research

    NASA Astrophysics Data System (ADS)

    Cuff, K. E.; Corazza, L.

    2006-12-01

    Over the past eight years we have developed and implemented several U.C. Berkeley-based outreach programs that provide opportunities for grades nine through eleven students in the East San Francisco Bay Area to gain skills and understandings that increase their capacity to enroll and perform successfully in science, technology, engineering, and mathematics (STEM) courses in the future, which enhances their capacity to decide to pursue STEM careers. A common element of these programs is the opportunity they provide participants to engage in environmental science research projects that are directly linked to relevant, real-world environmental problems and issues facing their communities. Analysis of evidence gleaned from questionnaires, interviews and specific assessment instruments indicates that these programs have consistently achieved a high degree of success in that they have: significantly increased participants' understanding of the process and nature of science; enhanced their intellectual self-confidence with regard to STEM; developed deeper appreciation of how scientific research can contribute to the maintenance of healthy local environments; developed a greater interest in participating in STEM-related courses of study and after school programs; and improved attitudes toward STEM. These results corroborate recent research studies that indicate a close relationship between educational activities that promote the perception of STEM as being relevant and the ability to foster development of deeper conceptual understandings among teens. Moreover, they support the notion that providing opportunities for students to develop personal connections with particular issues discussed, and real-world STEM experiences that make STEM more relevant and interesting can help to bring about changes in attitude, which is a key component in improving STEM learning and understanding particularly among urban youth. Overall, our work suggests that in order for a given STEM

  6. Monensin is not toxic to aquatic macrophytes at environmentally relevant concentrations.

    PubMed

    McGregor, Erin B; Solomon, K R; Hanson, M L

    2007-11-01

    Monensin, a common livestock feed additive, has been detected in surface waters around areas of intensive agriculture. The effect of this ionophore antibiotic on floating (Lemna gibba) and submersed (Myriophyllum spicatum, Elodea canadensis, Egeria densa) freshwater macrophytes was investigated under seminatural field conditions using 12,000 l of outdoor microcosms. Exposure concentrations of 0, 12, 25, 50, and 100 mug/l (n = 3) were evaluated over a 35-day period. Submersed plants were grown individually in 115-ml plastic "cone-tainers" and assessed for various growth and pigment end points. E. canadensis and M. spicatum also were grown in assemblages to represent model populations and two-species communities. Few statistically significant differences from control organisms were observed for any of the monitored end points. Overall, monensin is deemed unlikely to cause toxicity in freshwater macrophytes at current environmental concentrations. However, the ability to characterize toxicity in macrophytes is based partially on the relative growth rates (RGRs) of the plants. The greater the RGR, the more sensitive the assay may be to contaminants. The RGRs of E. canadensis and M. spicatum grown in model populations and communities were found to be significantly higher than the RGRs of plants grown individually. This implies that the "cone-tainer" method, although simple and easy to perform, may underestimate toxicity in simulated field studies.

  7. Low-Temperature Magnetic Properties of Environmentally Relevant Iron Oxyhydroxides and Their Alteration Products

    NASA Astrophysics Data System (ADS)

    Guyodo, Y. J.; Lagroix, F.; Ona-Nguema, G.; Bonville, P.

    2011-12-01

    Iron oxyhydroxides such as ferrihydrite or lepidocrocite are weakly magnetic mineral that are thought to be, in some environments, precursors of more magnetic phases such as magnetite or maghemite. Deciphering the alteration pathways of these minerals, and others, should allow quantified interpretations of sediment magnetic properties in terms of climate and environmental change in various natural settings. At this meeting, we will present recent low temperature magnetic properties acquired on synthetic iron oxyhydroxides. Comparison of these low-temperature data with other characterizations (e.g., HR-TEM, Mossbauer, XMCD) point to the complex nature of the magnetism of these minerals, which can no longer be considered as simple antiferromagnets. Results from alteration experiments using these minerals as starting material will also be presented. Several experimental approaches have been used for these alterations, including bio-reduction using Shewanella putrefaciens and solid-state reduction (or oxidation) by slow heating in CO/CO2 (or in air). The low-temperature magnetic properties of the resulting materials actually help in building conceptual structural/compositional models explaining the unusual low-temperature magnetic behavior of the initial iron oxyhydroxides.

  8. Environmentally relevant concentrations of aminopolycarboxylate chelating agents mobilize Cd from humic acid.

    PubMed

    North, Ashley E; Sarpong-Kumankomah, Sophia; Bellavie, Andrew R; White, Wade M; Gailer, Jürgen

    2017-07-01

    Although Cd is a pollutant of public health relevance, many dietary sources from which it can be absorbed into human tissues remain unknown. While it is well established that the biogeochemical cycle of Cd involves its complexation with environment-derived ligands (e.g., humic acids, HAs) and anthropogenic ones (e.g., chelating agents, CAs), the interaction of Cd with both of these ligands is less well understood. To gain insight, a HA-Cd complex was injected on a size-exclusion chromatography (SEC) column coupled on-line with a flame atomic absorption spectrometer (FAAS) using 10mmol/L Tris buffer (pH8.0) as the mobile phase. This approach allowed us to observe the intact HA-Cd complex and the retention behavior of Cd as a function of 2-20μmol/L concentrations of ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) or methylglycinediacetic acid (MGDA) that were added to the mobile phase. An increase of the retention time of Cd was indicative of a partial or complete abstraction of Cd from HA. Our results revealed that all CAs abstracted Cd from the HA-Cd complex at concentrations of 5μmol/L, while MGDA and DTPA were effective at 2μmol/L. The bioavailability of some of the on-column formed CA-Cd complexes explains the previously reported increased accumulation of Cd in periphyton in the ecosystem downstream of wastewater treatment plants. In addition, our results imply that the use of effluents which contain CAs and Cd for the irrigation of food crops can introduce Cd into the food supply and compromise food safety. Copyright © 2017. Published by Elsevier B.V.

  9. Transcriptional response of the archaeal ammonia oxidizer Nitrosopumilus maritimus to low and environmentally relevant ammonia concentrations.

    PubMed

    Nakagawa, Tatsunori; Stahl, David A

    2013-11-01

    The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopumilus maritimus SCM1 growing at two ammonia concentrations, as measured by combined ammonia and ammonium, one well above the Km for ammonia oxidation (∼500 μM) and the other well below the Km (<10 nM). Transcript levels were generally immediately and differentially repressed when cells transitioned from ammonia-replete to ammonia-limiting conditions. Transcript levels for ammonia oxidation, CO2 fixation, and one of the ammonia transport genes were approximately the same at high and low ammonia availability. Transcripts for all analyzed genes decreased with time in the complete absence of ammonia, but with various rates of decay. The new steady-state mRNA levels established are presumably more reflective of the natural physiological state of ammonia-oxidizing archaea and offer a reference for interpreting message abundance patterns in the natural environment.

  10. Transcriptional Response of the Archaeal Ammonia Oxidizer Nitrosopumilus maritimus to Low and Environmentally Relevant Ammonia Concentrations

    PubMed Central

    Stahl, David A.

    2013-01-01

    The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopumilus maritimus SCM1 growing at two ammonia concentrations, as measured by combined ammonia and ammonium, one well above the Km for ammonia oxidation (∼500 μM) and the other well below the Km (<10 nM). Transcript levels were generally immediately and differentially repressed when cells transitioned from ammonia-replete to ammonia-limiting conditions. Transcript levels for ammonia oxidation, CO2 fixation, and one of the ammonia transport genes were approximately the same at high and low ammonia availability. Transcripts for all analyzed genes decreased with time in the complete absence of ammonia, but with various rates of decay. The new steady-state mRNA levels established are presumably more reflective of the natural physiological state of ammonia-oxidizing archaea and offer a reference for interpreting message abundance patterns in the natural environment. PMID:23995944

  11. Incubation of solid state C60 fullerene under UV irradiation mimicking environmentally relevant conditions.

    PubMed

    Carboni, Andrea; Helmus, Rick; Parsons, John R; Kalbitz, Karsten; de Voogt, Pim

    2017-05-01

    Carbon-based nanomaterials, such as C60 fullerenes, are expected to accumulate in soil due to direct release and deposition from the atmosphere. However, little is known about the environmental fate of these nanoparticles which may be susceptible to photochemical and microbial degradation. In the present work, C60 was incubated for a period of 28 days and irradiated with UVA light. Three experiments were carried out where the fullerenes were either spiked onto a glass surface or added to quartz sand or sandy soil samples. At specific time intervals the samples were extracted and analysed by liquid chromatography coupled to UV or high resolution mass spectrometric (HRMS) detection. The fullerenes were degraded in all the treatments and the decay followed a pseudo-first-order rate law. In absence of a solid matrix, the half-life (t1⁄2) of the C60 was 13.1 days, with an overall degradation of 45.1% that was accompanied by the formation of functionalized C60-like structures. Furthermore, mass spectrometric analysis highlighted the presence of a large number of transformation products that were not directly related to the irradiation and presented opened cage and oxidized structures. When C60 was spiked into solid matrices the degradation occurred at a faster rate (t1⁄2 of 4.5 and 0.8 days for quartz sand and sandy soil, respectively). Minor but consistent losses were found in the non-irradiated samples, presumably due to biotic or chemical processes occurring in these samples. The results of this study suggest that light-mediated transformation of the fullerenes will occur in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Features of Microglia and Neuroinflammation Relevant to Environmental Exposure and Neurotoxicity

    PubMed Central

    Kraft, Andrew D.; Harry, G. Jean

    2011-01-01

    Microglia are resident cells of the brain involved in regulatory processes critical for development, maintenance of the neural environment, injury and repair. They belong to the monocytic-macrophage lineage and serve as brain immune cells to orchestrate innate immune responses; however, they are distinct from other tissue macrophages due to their relatively quiescent phenotype and tight regulation by the CNS microenvironment. Microglia actively survey the surrounding parenchyma and respond rapidly to changes such that any disruption to neural architecture or function can contribute to the loss in regulation of the microglia phenotype. In many models of neurodegeneration and neurotoxicity, early events of synaptic degeneration and neuronal loss are accompanied by an inflammatory response including activation of microglia, perivascular monocytes, and recruitment of leukocytes. In culture, microglia have been shown to be capable of releasing several potentially cytotoxic substances, such as reactive oxygen intermediates, nitric oxide, proteases, arachidonic acid derivatives, excitatory amino acids, and cytokines; however, they also produce various neurotrophic factors and quench damage from free radicals and excitotoxins. As the primary source for pro-inflammatory cytokines, microglia are implicated as pivotal mediators of neuroinflammation and can induce or modulate a broad spectrum of cellular responses. Neuroinflammation should be considered as a balanced network of processes whereby subtle modifications can shift the cells toward disparate outcomes. For any evaluation of neuroinflammation and microglial responses, within the framework of neurotoxicity or degeneration, one key question in determining the consequence of neuroinflammation is whether the response is an initiating event or the consequence of tissue damage. As examples of environmental exposure-related neuroinflammation in the literature, we provide an evaluation of data on manganese and diesel exhaust

  13. Selective uptake and biological consequences of environmentally relevant antidepressant pharmaceutical exposures on male fathead minnows

    USGS Publications Warehouse

    Schultz, M.M.; Painter, M.M.; Bartell, S.E.; Logue, A.; Furlong, E.T.; Werner, S.L.; Schoenfuss, H.L.

    2011-01-01

    Antidepressant pharmaceuticals have been reported in wastewater effluent at the nanogram to low microgram-per-liter range, and include bupropion (BUP), fluoxetine (FLX), sertraline (SER), and venlafaxine (VEN). To assess the effects of antidepressants on reproductive anatomy, physiology, and behavior, adult male fathead minnows (Pimephales promelas) were exposed for 21 days either to a single concentration of the antidepressants FLX, SER, VEN, or BUP, or to an antidepressant mixture. The data demonstrated that exposure to VEN (305. ng/L and 1104. ng/L) and SER (5.2. ng/L) resulted in mortality. Anatomical alterations were noted within the testes of fish exposed to SER and FLX, both modulators of the neurotransmitter serotonin. Additionally, FLX at 28. ng/L induced vitellogenin in male fish-a common endpoint for estrogenic endocrine disruption. Significant alterations in male secondary sex characteristics were noted with single exposures. Effects of single compound exposures neither carried over, nor became additive in the antidepressant mixtures, and reproductive behavior was not affected. Analysis of brain tissues from the exposed fish suggested increased uptake of FLX, SER and BUP and minimal uptake of VEN when compared to exposure water concentrations. Furthermore, the only metabolite detected consistently in the brain tissues was norfluoxetine. Similar trends of uptake by brain tissue were observed when fish were exposed to antidepressant mixtures. The present study demonstrates that anatomy and physiology, but not reproductive behavior, can be disrupted by exposure to environmental concentrations of some antidepressants. The observation that antidepressant uptake into fish tissues is selective may have consequences on assessing the mode-of-action and effects of these compounds in future studies. ?? 2011 Elsevier B.V.

  14. Selective uptake and biological consequences of environmentally relevant antidepressant pharmaceutical exposures on male fathead minnows

    USGS Publications Warehouse

    Schultz, Melissa M.; Painter, Meghan M.; Bartell, Stephen E.; Logue, Amanda; Furlong, Edward T.; Werner, Stephen L.; Schoenfuss, Heiko L.

    2011-01-01

    Antidepressant pharmaceuticals have been reported in wastewater effluent at the nanogram to low microgram-per-liter range, and include bupropion (BUP), fluoxetine (FLX), sertraline (SER), and venlafaxine (VEN). To assess the effects of antidepressants on reproductive anatomy, physiology, and behavior, adult male fathead minnows (Pimeplwles promelas) were exposed for 21 days either to a single concentration of the antidepressants FLX, SER, VEN, or BUP, or to an antidepressant mixture. The data demonstrated that exposure to VEN (305 ng/L and 1104 ng/L) and SER (5.2 ng/L) resulted in mortality. Anatomical alterations were noted within the testes of fish exposed to SER and FLX, both modulators of the neurotransmitter serotonin. Additionally, FLX at 28 ng/L induced vitellogenin in male fish—a common endpoint for estrogenic endocrine disruption. Significant alterations in male secondary sex characteristics were noted with single exposures. Effects of single compound exposures neither carried over, nor became additive in the antidepressant mixtures, and reproductive behavior was not affected. Analysis of brain tissues from the exposed fish suggested increased uptake of FLX, SER and BUP and minimal uptake of VEN when compared to exposure water concentrations. Furthermore, the only metabolite detected consistently in the brain tissues was norfluoxetine. Similar trends of uptake by brain tissue were observed when fish were exposed to antidepressant mixtures. The present study demonstrates that anatomy and physiology, but not reproductive behavior, can be disrupted by exposure to environmental concentrations of some antidepressants. The observation that antidepressant uptake into fish tissues is selective may have consequences on assessing the mode-of-action and effects of these compounds in future studies.

  15. Enrofloxacin at environmentally relevant concentrations enhances uptake and toxicity of cadmium in the earthworm Eisenia fetida in farm soils.

    PubMed

    Li, Yinsheng; Tang, Hao; Hu, Yingxiu; Wang, Xiuhong; Ai, Xiaojie; Tang, Li; Matthew, Cory; Cavanagh, Jo; Qiu, Jiangping

    2016-05-05

    Individual and combined effects of enrofloxacin (EF) and cadmium (Cd) on the earthworm Eisenia fetida at environmentally relevant concentrations were investigated. EF is a veterinary antibiotic; Cd is an impurity in phosphatic fertiliser. For both, residues may accumulate in farm soils. In laboratory tests, over 98% of spiked EF was adsorbed by farm soils, with a half-life >8 weeks. However, earthworms absorbed less than 20% of spiked EF. Earthworms in soil with EF concentration 10 mg kg(-1) soil experienced transient oxidative stress and exhibited reduced burrowing activity and respiration after an 8-week exposure; EF at 0.1 and 1.0 mg kg(-1) soil did not elicit toxicity symptoms. When both were added, Cd did not affect EF uptake, but each increment of spiked EF increased Cd bioaccumulation and associated oxidative stress of earthworms, and also caused decreased burrow length and CO2 production. However, metallothionein induction was not affected. The enhanced toxicity of Cd to earthworms in the presence of EF at low environmental concentrations may have implications for the health and reproductive success of earthworm populations and highlights the importance of understanding effects of antibiotic contamination of farm soils, and of awareness of environmental effects from interaction between multiple contaminants.

  16. Environmentally relevant xenoestrogen tissue concentrations correlated to biological responses in mice.

    PubMed Central

    Ulrich, E M; Caperell-Grant, A; Jung, S H; Hites, R A; Bigsby, R M

    2000-01-01

    The effects of xenoestrogens have been extensively studied in rodents, generally under single, high-dose conditions. Using a continuous-release, low-dose system in ovariectomized mice, we correlated the estrogenic end points of uterine epithelial height (UEH) and vaginal epithelial thickness (VET) with concentrations of two organochlorine pesticide isomers in fat and blood. Silastic capsules containing a range of doses of either ss-hexachlorocyclohexane (ss-HCH) or o, p'-dichlorodiphenyltrichloroethane (o,p'-DDT) were implanted subcutaneously, and animals were killed after 1 week. Average blood levels achieved by the various doses were 4.2-620 ng/mL for o,p'-DDT and 5.0-300 ng/mL for ss-HCH. Fat concentrations of o,p'-DDT and ss-HCH correlated linearly to blood levels (o,p'-DDT, r(2) = 0.94; ss-HCH, r(2) = 0.83). Fat concentrations (nanograms per gram of tissue) were higher than blood concentrations (nanograms per milliliter) by 90 +/- 5- and 120 +/- 9-fold (mean +/- SE) for o, p'-DDT and ss-HCH, respectively. The VET ranged from 12 +/- 0.9 microm in controls to 114 +/- 8 microm in treated animals, and was correlated to blood levels of either treatment compound. The UEH ranged from an average of 7.7 +/- 0.3 microm in controls to 26 +/- 2 microm in high-dose o,p'-DDT-treated animals. The UEH was also correlated with ss-HCH concentration, but it plateaued at approximately 11 microm at the highest doses. The lowest blood concentrations that produced statistically significant increases in VET or UEH were 18 +/- 2 ng/mL o,p'-DDT and 42 +/- 4 ng/mL ss-HCH. These values are within the same order of magnitude of blood concentrations found in some human subjects from the general population, suggesting that human blood concentrations of these organochlorines may reach estrogenic levels. PMID:11049819

  17. Estradiol and endocrine disrupting compounds adversely affect development of sea urchin embryos at environmentally relevant concentrations.

    PubMed

    Roepke, Troy A; Snyder, Mark J; Cherr, Gary N

    2005-01-26

    Environmental endocrine disrupting compounds (EDCs) are a wide variety of chemicals that typically exert effects, either directly or indirectly, through receptor-mediated processes, thus mimicking endogenous hormones and/or inhibiting normal hormone activities and metabolism. Little is known about the effects of EDCs on echinoderm physiology, reproduction and development. We exposed developing sea urchin embryos (Strongylocentrotus purpuratus and Lytechinus anamesus) to two known EDCs (4-octylphenol (OCT), bisphenol A (BisA)) and to natural and synthetic reproductive hormones (17beta-estradiol (E2), estrone (E1), estriol (E3), progesterone (P4) and 17alpha-ethynylestradiol (EE2)). In addition, we studied two non-estrogenic EDCs, tributyltin (TBT) and o,p-DDD. Successful development to the pluteus larval stage (96 h post-fertilization) was used to define EDC concentration-response relationships. The order of compound potency based on EC50 values for a reduction in normal development was as follows: TBT(L. anamesus)>OCT>TBT(S. purpuratus)>E2>EE2>DDD>BisA>P4>E1>E3. The effect of TBT was pronounced even at concentrations substantially lower than those commonly reported in heavily contaminated areas, but the response was significantly different in the two model species. Sea urchin embryos were generally more sensitive to estrogenic EDCs and TBT than most other invertebrate larvae. Stage-specific exposure experiments were conducted to determine the most sensitive developmental periods using blastula, gastrula and post-gastrula (pluteus) stages. The stage most sensitive to E2, OCT and TBT was the blastula stage with less overall sensitivity in the gastrula stage, regardless of concentration. Selective estrogen receptor modulators (SERMs) were added to the experiments individually and in combination with estrogenic EDCs to interfere with potential receptor-mediated actions. Tamoxifen, a partial ER agonist, alone inhibited development at concentrations as low as 0.02 ng

  18. Considerations for Architecture Level Trade Studies for Environmental Sensors

    NASA Technical Reports Server (NTRS)

    Peterson, Craig

    2010-01-01

    Comparisons of key characteristics of environmental sensors such as technology readiness levels, mass, power, volume, and detection capabilities are essential for initial trade studies to determine likely candidates for further development and evaluation. However, these trade studies only provide part of the information necessary to make selection decisions. Ultimately, the sensors must be judged based on the overall system architectures and operational scenarios for which they are intended. This means that additional characteristics, such as architectural needs for redundancy, operational lifetime, ability to maintain calibration, and repair and replacement strategies, among others, must also be considered. Given that these characteristics can be extremely time-consuming and costly to obtain, careful planning is essential to minimize the effort involved. In this paper, an approach is explored for determining an effective yet comprehensive set of architecture level trades which is minimally impacted by the inevitable changes in operational (mission) scenarios. The approach will also identify and integrate the various facilities and opportunities required to obtain the desired architecture level trade information.

  19. The Relevance of Social Theory in the Practice of Environmental Management.

    PubMed

    Meissner, Richard

    2016-10-01

    In this paper I argue that the dominance of certain paradigms and theories on policies can have an influence on the value added by impact assessments. A link exists between paradigms and theories and policies and consequently the practices humans develop to tackle real world problems. I also argue that different types of thinking (contained in paradigms and theories) need to be integrated, at least at the scientific level, to enhance our understanding of social phenomena. This in turn can have a positive influence on policy processes that follow impact assessment recommendations. I am not arguing for the adoption of theoretical positions by practitioners, Instead, I contend that if impact assessments are informed by a variety of paradigms and theories, the policy practitioner might have a better understanding of the issue and the moral choices he or she needs to make. I will highlight the connection between theory and policies with practical examples from the social impact assessment of the De Hoop Dam, which was constructed on the Steelpoort River. I also argue for an integration of different theories to give a deeper understanding of real world problems.

  20. Genomic and proteomic responses to environmentally relevant exposures to dieldrin: indicators of neurodegeneration?

    PubMed

    Martyniuk, Christopher J; Kroll, Kevin J; Doperalski, Nicholas J; Barber, David S; Denslow, Nancy D

    2010-09-01

    Dieldrin is a persistent organochlorine pesticide that induces neurotoxicity in the vertebrate central nervous system and impairs reproductive processes in fish. This study examined the molecular events produced by subchronic dietary exposures to 2.95 mg dieldrin/kg feed in the neuroendocrine brain of largemouth bass, an apex predator. Microarrays, proteomics, and pathway analysis were performed to identify genes, proteins, and cell processes altered in the male hypothalamus. Fifty-four genes were induced, and 220 genes were reduced in steady-state levels (p < 0.001; fold change greater than +/- 1.5). Functional enrichment analysis revealed that the biological gene ontology categories of stress response, nucleotide base excision repair, response to toxin, and metabolic processes were significantly impacted by dieldrin. Using isobaric tagging for relative and absolute quantitation, 90 proteins in the male hypothalamus were statistically evaluated for changes in protein abundance. Several proteins altered by dieldrin are known to be associated with human neurodegenerative diseases, including apolipoprotein E, microtubule-associated tau protein, enolase 1, stathmin 1a, myelin basic protein, and parvalbumin. Proteins altered by dieldrin were involved in oxidative phosphorylation, differentiation, proliferation, and cell survival. This study demonstrates that a subchronic exposure to dieldrin alters the abundance of messenger RNAs and proteins in the hypothalamus that are associated with cell metabolism, cell stability and integrity, stress, and DNA repair.

  1. Genomic and Proteomic Responses to Environmentally Relevant Exposures to Dieldrin: Indicators of Neurodegeneration?

    PubMed Central

    Martyniuk, Christopher J.; Kroll, Kevin J.; Doperalski, Nicholas J.; Barber, David S.; Denslow, Nancy D.

    2010-01-01

    Dieldrin is a persistent organochlorine pesticide that induces neurotoxicity in the vertebrate central nervous system and impairs reproductive processes in fish. This study examined the molecular events produced by subchronic dietary exposures to 2.95 mg dieldrin/kg feed in the neuroendocrine brain of largemouth bass, an apex predator. Microarrays, proteomics, and pathway analysis were performed to identify genes, proteins, and cell processes altered in the male hypothalamus. Fifty-four genes were induced, and 220 genes were reduced in steady-state levels (p < 0.001; fold change greater than ± 1.5). Functional enrichment analysis revealed that the biological gene ontology categories of stress response, nucleotide base excision repair, response to toxin, and metabolic processes were significantly impacted by dieldrin. Using isobaric tagging for relative and absolute quantitation, 90 proteins in the male hypothalamus were statistically evaluated for changes in protein abundance. Several proteins altered by dieldrin are known to be associated with human neurodegenerative diseases, including apolipoprotein E, microtubule-associated tau protein, enolase 1, stathmin 1a, myelin basic protein, and parvalbumin. Proteins altered by dieldrin were involved in oxidative phosphorylation, differentiation, proliferation, and cell survival. This study demonstrates that a subchronic exposure to dieldrin alters the abundance of messenger RNAs and proteins in the hypothalamus that are associated with cell metabolism, cell stability and integrity, stress, and DNA repair. PMID:20584760

  2. Alkoxyresorufin metabolism in white-footed mice at relevant environmental concentrations of Aroclor 1254

    SciTech Connect

    Simmons, G.J.; McKee, M.J. )

    1992-10-01

    Recent investigations have detected polychlorinated biphenyl (PCB) body burdens in wild white-footed mice (Peromyscus leucopus) captured at hazardous waste sites. Insufficient information is currently available to interpret the toxicological significance of these body burdens. In an effort to provide this information, we investigated hepatic changes and PCB body burdens in white-footed mice following a 21-day dietary exposure to a PCB mixture, Aroclor 1254. Dietary concentrations tested were 0, 2.5, 25, 50, and 100 mg Aroclor 1254/kg diet (reported as ppm). Liver weights were significantly increased at all concentrations except 2.5 ppm. Ethoxyresorufin O-dealkylase (EROD) activity, an aryl hydrocarbon hydroxylase-type substrate, was significantly increased at all PCB concentrations, but the dose-response tended to plateau above 25 ppm. Pentoxyresorufin O-dealkylase (PROD) activity, a putative phenobarbital-type substrate, was significantly increased in a dose-dependent manner at 25 ppm PCB and above, with no plateau response. Pentobarbital sleep time was significantly decreased at 25 ppm, but not at 2.5 ppm. Results indicate white-footed mice undergo a mixed-type induction pattern following exposure to Aroclor 1254, with EROD the most sensitive indicator of PCB exposure. This investigation identified a no observed effect concentration for liver weights and PROD activity at 2.5 ppm in the diet which is equivalent to a body burden of 2.0 mg Aroclor 1254/kg wet wt of mice; the no observed effect concentration for EROD is below these levels. These results support the use of EROD, PROD, and liver weight as biomarkers of PCB exposure in field-captured rodents.

  3. Chronic exposure to environmentally relevant concentrations of PCB causes reproductive toxicity in mink

    SciTech Connect

    Brunstroem, B.; Oerberg, J.; Lund, B.O.; Athanasiadou, M.

    1995-12-31

    Female mink (Mustela vison) were exposed to the technical PCB preparation Clophen A50 (0.3 or 0.1 mg/animal/day) in the feed for 18 months, including two reproduction seasons. Isomer-specific PCB-analysis of the technical mixture was made and the concentrations of toxic equivalents (TEQs) in the feed were calculated. In addition, Clophen A50 was separated into two fractions, one containing the non and mono-ortho-chlorinated PCB congeners (planar fraction) and the other containing congeners with 2-4 chlorines in ortho-position (non-planar fraction). Animals in two separate groups were exposed daily to these individual fractions extracted from 0.3 mg Clophen A50. No effect on the reproduction outcome was observed during the first reproduction season. However, reduced birth weights were noted in the kits born to animals treated with 0.3 mg Clophen A50 per day. The reproductive performance was seriously affected in the second season. Only 39% of the females exposed to 0.3 mg Clophen A50 per day whelped, compared with 93% in the control group. All whelps in the group exposed to the high dose of Clophen A50 died within 1 day after birth. Kit survival and growth were reduced also in the group treated with the low dose of Clophen A50. Treatment with the non and mono-orthochlorinated PCB congeners strongly reduced kit survival and body weight gain. Only 8% of the kits survived until 2 weeks of age. It is concluded that the non and monoortho-chlorinated PCB congeners were responsible for the major part of the reproductive toxicity caused by Clophen A50. PCB residue concentrations in the mink, determined at the end of the experiment, were within the range of the levels that have been observed in wild mink in Sweden.

  4. ACUTE EXPOSURE TO AN ENVIRONMENTALLY-RELEVANT CONCENTRATION OF DICLOFENAC ELICITS OXIDATIVE STRESS IN THE CULTURALLY IMPORTANT GALAXIID FISH, GALAXIAS MACULATUS.

    PubMed

    Mcrae, Nicole K; Glover, Chris N; Burket, S Rebekah; Brooks, Bryan W; Gaw, Sally

    2017-08-12

    Diclofenac is a non-steroidal anti-inflammatory drug of growing concern in aquatic environments worldwide, yet knowledge of its effects on aquatic biota are restricted to a few model species and mechanisms of impact. In the current study, diclofenac accumulation, its effects on metabolic rate, ionoregulation, and oxidative stress were examined at environmentally-relevant (0.17 μg L-1) and elevated (763 μg L-1) concentrations in a culturally and economically important galaxiid fish, inanga (Galaxias maculatus), from the Southern Hemisphere. This species is among the most widespread freshwater fish in the world, yet its sensitivity to emerging contaminants is unknown. Following an acute 96 h exposure, bioconcentration of diclofenac was measured in inanga whole body, resulting in an estimated bioconcentration factor of 87 for the 0.17 μg L-1 exposure concentration, approaching values where transfer through the food chain should be considered. Lipid peroxidation in the liver was significantly elevated at both 0.17 and 763 μg L-1 exposure concentrations, but lipid peroxidation in kidney and gill decreased after diclofenac exposure. Catalase activity was also elevated in the liver of inanga, but activity decreased in the gill. There were no effects of diclofenac on metabolic rate or ion (sodium and calcium) influx rates. These data indicate toxicologically-relevant adverse outcomes and bioconcentration of diclofenac at environmentally-relevant levels warrant additional study in this important fish. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Environmentally relevant concentrations of ethynylestradiol cause female-biased sex ratios in Xenopus tropicalis and Rana temporaria.

    PubMed

    Pettersson, Irina; Berg, Cecilia

    2007-05-01

    The susceptibility of Xenopus (Silurana) tropicalis and Rana temporaria to ethynylestradiol (EE2), a potent estrogenic pharmaceutical and environmental pollutant, was investigated. Larval EE2 exposure caused female-biased sex ratios at concentrations as low as 0.06 nM, which is comparable to levels found in the environment. The susceptibility of the two frog species to EE2 was comparable, supporting the use of X. tropicalis as a model organism for research on developmental reproductive toxicity of estrogenic pollutants.

  6. Environmental relevant concentrations of a chlorpyrifos commercial formulation affect two neotropical fish species, Cheirodon interruptus and Cnesterodon decemmaculatus.

    PubMed

    Bonifacio, Alejo Fabian; Ballesteros, María Laura; Bonansea, Rocío Inés; Filippi, Iohanna; Amé, María Valeria; Hued, Andrea Cecilia

    2017-12-01

    The increase of cultivated areas together with the intensive use of pesticides have greatly contributed to impair the quality of aquatic systems along different areas of South America. The main goal of the present study was to assess the effects of a commercial formulation of chlorpyrifos at environmentally relevant concentrations on two native fish species, Cheirodon interruptus and Cnesterodon decemmaculatus. Adult individuals were exposed during 48 h to the following concentrations: 0.084 nl/l (Ci-Cf 1) and 0.84 nl/l (Ci-CF 2) in C. interruptus (Ci) of Clorfox (CF), and 0.84 nl/l (Cd-CF 1) and 8.4 nl/l (Cd-CF 2) in C. decemmaculatus (Cd). Fish behavior was evaluated through locomotor activity and space usage variables. The activity of acetylcholinesterase (AChE) in brain and muscle, catalase (CAT) and glutathione-S-transferase (GST) in brain, liver, muscle and gills, and aspartate amino-transferase (AST), alanine amino-transferase (ALT), AST/ALT ratio and alkaline phosphatase (ALP) in liver, were measured. Both locomotor activity and space usage varied between the two species studied and between CF treatments. The enzyme activities showed significant variations in CAT for C. interruptus and in CAT, GST, AChE, AST, and AST/ALT for C. decemmaculatus under the exposure conditions. Given that both species responded to CF and the concentrations we tested are environmentally relevant, the presence of this pesticide in freshwater systems could impose a risk for populations of both native fish studied at field. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Environmental awareness and level-dependent hearing protection devices.

    PubMed

    Lindley, G A; Palmer, C V; Goldstein, H; Pratt, S

    1997-02-01

    The effect of level-dependent hearing protection devices (HPDs) on subjects' ability to identify real-life environmental sounds was investigated. Eighteen subjects with no hunting experience attempted to identify sounds (crow, duck, turkey, deer, owl, goose, and person) recorded at various distances in the presence of the SoundScope and Sonic II level-dependent HPDs as well as in an open ear condition. Knowles Electronic's Manikin for Auditory Research was employed in making the experimental recordings. The Sonic II accomplishes level-dependent attenuation via a passive mechanism, whereas the SoundScope employs active circuitry that attenuates loud sounds while providing a small amount of high frequency amplification for soft sounds. Both devices are commercially available and are advertised for hunters/shooters. Sound identification scores (SISs) were determined for each condition. Mean SISs differed significantly among the three earplug conditions, collapsed over type of sound and distance, with the best SIS obtained under the open ear condition (96.43%) and the worst under the Sonic II condition (84.13%). Further analysis revealed that the listening conditions differed significantly only at the 100 yard distance. Auditory awareness was not maintained by either device investigated during the 100 yard condition. However, auditory awareness was maintained by both devices at a distance of 75 yards or closer. These devices may be appropriate for use in certain hunting/shooting situations depending on several factors including type of game being hunted, environment, and shooting range of the weapon. Further support also is provided for the usage of level-dependent HPDs during recreational shooting activities (i.e., at a shooting range).

  8. Effects of environmentally relevant concentrations of metallic compounds on the flatfish Scophthalmus maximus: biomarkers of neurotoxicity, oxidative stress and metabolism.

    PubMed

    Nunes, Bruno; Brandão, Fátima; Sérgio, Tânia; Rodrigues, Sara; Gonçalves, Fernando; Correia, Alberto Teodorico

    2014-06-01

    Flatfish species, such as the turbot (Scophthalmus maximus), are common targets for toxic effects, since they are exposed through the food chain (ingestion of contaminated preys) and are in direct contact with the waterborne contaminant and sediments. Furthermore, these fish species live in close proximity to interstitial water that frequently dissolves high amounts of contaminants, including metals. Despite this significant set of characteristics, the present knowledge concerning flatfish contamination and toxicity by metals is still scarce. To attain the objective of assessing the effects of metals on a flatfish species, S. maximus specimens were chronically exposed to lead, copper and zinc, at ecologically relevant concentrations, and biochemical (oxidative stress: catalase and glutathione S-transferases activities, and lipid peroxidation; neurotoxicity: cholinesterase activity) parameters were assessed on selected tissues (gills and liver). Copper had no significant effects on all tested parameters; lead was causative of significant increases in liver GSTs activities and also in lipoperoxidation of gill tissue; exposure to zinc caused a significant increase in catalase activity of gill tissue. None of the tested metals elicited noteworthy effects in terms of neurotoxicity. The obtained results showed that only the metal lead is of some environmental importance, since it was able to cause deleterious modifications of oxidative nature at relevant concentrations.

  9. Effect of relevant environmental stresses on survival of enterohemorrhagic Escherichia coli in dry-fermented sausage.

    PubMed

    McLeod, Anette; Måge, Ingrid; Heir, Even; Axelsson, Lars; Holck, Askild L

    2016-07-16

    Dry-fermented sausages (DFSs) have been linked to several serious foodborne outbreaks of enterohemorrhagic Escherichia coli (EHEC). The ability of pathogens to utilize adaptive responses to different stressful conditions intended to control their growth in foods, food preparation and production processes may enhance their survival. In certain cases, induced tolerance to one type of stress may lead to enhanced resistance to the applied stress as well as to other stresses. We exposed two EHEC strains, MF3582 of serotype O157:H- and MF5554 of serogroup O145, to different stresses commonly encountered during a production process. The two EHEC strains, previously shown to have different abilities to survive DFS production process conditions, were subjected to low temperatures (4°C and 12°C), 5% NaCl or 1% lactic acid for 6days prior to being added to sausage batters. Survival of EHEC was recorded in salami of two recipes, fermented at two temperatures (20°C and 30°C). The results showed that recipe type had the largest impact on EHEC reductions where Moderate recipe (MR) salami batters containing increased levels of NaCl, glucose and NaNO2 provided enhanced EHEC reductions in salami (2.6 log10) compared to Standard recipe (SR) salami (1.7 log10). Effects of pre-exposure stresses were dependent both on strain and recipe. While acid adaptation of MF5554 provided enhanced log10 reductions from 2.0 to 3.0 in MR sausages, adaptation to a combination of acid and salt stress showed the opposite effect in SR sausages with reductions of only 1.1 log10 as compared to the average of 1.8 log10 for the other SR sausages. Otherwise, the salt and acid adaptation single stresses had relatively small effects on EHEC survival through the DFS production process and subsequent storage and freeze/thaw treatments. Growing cells and cells frozen in batter survived poorly in MR sausages with an average reduction of 3.4 and 3.2 log10, respectively. The reductions of EHEC after storage of

  10. Streptococcus pneumoniae folate biosynthesis responds to environmental CO2 levels.

    PubMed

    Burghout, Peter; Zomer, Aldert; van der Gaast-de Jongh, Christa E; Janssen-Megens, Eva M; Françoijs, Kees-Jan; Stunnenberg, Hendrik G; Hermans, Peter W M

    2013-04-01

    Although carbon dioxide (CO2) is known to be essential for Streptococcus pneumoniae growth, it is poorly understood how this respiratory tract pathogen adapts to the large changes in environmental CO2 levels it encounters during transmission, host colonization, and disease. To identify the molecular mechanisms that facilitate pneumococcal growth under CO2-poor conditions, we generated a random S. pneumoniae R6 mariner transposon mutant library representing mutations in 1,538 different genes and exposed it to CO2-poor ambient air. With Tn-seq, we found mutations in two genes that were involved in S. pneumoniae adaptation to changes in CO2 availability. The gene pca, encoding pneumococcal carbonic anhydrase (PCA), was absolutely essential for S. pneumoniae growth under CO2-poor conditions. PCA catalyzes the reversible hydration of endogenous CO2 to bicarbonate (HCO3(-)) and was previously demonstrated to facilitate HCO3(-)-dependent fatty acid biosynthesis. The gene folC that encodes the dihydrofolate/folylpolyglutamate synthase was required at the initial phase of bacterial growth under CO2-poor culture conditions. FolC compensated for the growth-phase-dependent decrease in S. pneumoniae intracellular long-chain (n > 3) polyglutamyl folate levels, which was most pronounced under CO2-poor growth conditions. In conclusion, S. pneumoniae adaptation to changes in CO2 availability involves the retention of endogenous CO2 and the preservation of intracellular long-chain polyglutamyl folate pools.

  11. Vintage-level energy and environmental performance of manufacturing establishments

    SciTech Connect

    Boyd, G.A.; Bock, M.J.; Neifer, M.J.; Karlson, S.H.; Ross, M.H.

    1994-05-01

    This report examines the relationship between an industrial plant`s vintage and its energy and environmental performance. Basic questions related to defining vintage and measuring the effects of the manufacturing industry`s vintage distribution of plant-level capacity and energy intensity are explored in general for six energy-intensive sectors (paper, chlorine, nitrogenous fertilizer, aluminum, steel, and cement) at the four-digit standard industrial classification (SIC) level and in detail for two sectors (steel and cement). Results show that greenfield (i.e., newly opened) plants in the paper, steel, and cement industries exhibit low fossil fuel intensities. These results are consistent with expectations. New plants in the paper and steel industries, where processes are undergoing electrification, exhibit high electricity intensities. An analysis of a subsector of the steel industry -- minimills that use scrap-based, electric arc furnaces -- reveals a decline in electricity intensity of 6.2 kilowatt-hours per ton for each newer year of installed vintage. This estimate is consistent with those of engineering studies and raises confidence that analyses of vintage effects in other industries could be conducted. When a vintage measure is assigned on the basis of investment data rather than trade association data, the vintage/performance relationship results for the cement industry are reasonably robust; thus, the analysis of vintage and performance could be extended to sectors for which only US Bureau of the Census data are available.

  12. Environmental bacteriophages active on biofilms and planktonic forms of toxigenic Vibrio cholerae: Potential relevance in cholera epidemiology.

    PubMed

    Naser, Iftekhar Bin; Hoque, M Mozammel; Abdullah, Ahmed; Bari, S M Nayeemul; Ghosh, Amar N; Faruque, Shah M

    2017-01-01

    Phages isolated from environmental waters in Bangladesh were tested for their host specificity towards V. cholerae O1 and O139, and the ability to disperse V. cholerae biofilms formed in the laboratory. Representative phages were further characterized by electron microscopy and whole genome sequencing. Selected phages were then introduced in various combinations to biofilms of toxigenic V. cholerae added to samples of river water, and the dispersion of biofilms as well as the growth kinetics of V. cholerae and the phages were monitored. A phage cocktail composed of three different phages isolated from surface waters in Bangladesh and designated as JSF7, JSF4, and JSF3 could significantly influence the distribution and concentration of the active planktonic form and biofilm associated form of toxigenic V. cholerae in water. While JSF7 showed a biofilm degrading activity and dispersed cells from both V. cholerae O1 and O139 derived biofilms thus increasing the concentration of planktonic V. cholerae in water, JSF4 and JSF3 showed strong bactericidal activity against V. cholerae O1 and O139 respectively. A mixture of all three phages could effectively reduce both biofilm-associated and planktonic V. cholerae in river water microcosms. Besides potential applicability in phage-mediated control of cholera, our results have relevance in appreciating possible intricate role of diverse environmental phages in the epidemiology of the disease, since both biofilms and phages influence the prevalence and infectivity of V. cholerae in a variety of ways.

  13. Investigation of coatings of natural organic matter on silver nanoparticles under environmentally relevant conditions by surface-enhanced Raman scattering.

    PubMed

    Kühn, Melanie; Ivleva, Natalia P; Klitzke, Sondra; Niessner, Reinhard; Baumann, Thomas

    2015-12-01

    The widespread use of engineered inorganic nanoparticles (EINP) leads to a growing risk for an unintended release into the environment. Despite the good characterization of EINP in regard to their function scale and the application areas, there is still a gap of knowledge concerning their behaviour in the different environmental compartments. Due to their high surface to volume ratio, surface properties and existence or development of a coating are of high importance for their stability and transport behaviour. However, analytical methods to investigate organic coatings on nanoparticles in aqueous media are scarce. We used Raman microspectroscopy in combination with surface-enhanced Raman scattering (SERS) to investigate humic acid coatings on silver nanoparticles under environmentally relevant conditions and in real world samples. This setup is more challenging than previous mechanistic studies using SERS to characterize the humic acids in tailored settings where only one type of organic matter is present and the concentrations of the nanoparticles can be easily adjusted to the experimental needs. SERS offers the unique opportunity to work with little sample preparation directly with liquid samples, thus significantly reducing artefacts. SERS spectra of different natural organic matter brought into contact with silver nanoparticles indicate humic acid in close proximity to the nanoparticles. This coating was also present after several washing steps by centrifugation and resuspension in deionized water and after an increase in ionic strength. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 77 FR 58416 - Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... COMMISSION Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste... Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste Spent Ion Exchange Resins from... Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste Spent Ion...

  15. Assessing the aggregation behaviour of iron oxide nanoparticles under relevant environmental conditions using a multi-method approach.

    PubMed

    Chekli, Laura; Phuntsho, Sherub; Roy, Maitreyee; Lombi, Enzo; Donner, Erica; Shon, Ho Kyong

    2013-09-01

    Iron nanoparticles are becoming increasingly popular for the treatment of contaminated soil and groundwater; however, their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Assessing their stability under environmental conditions is crucial for determining their environmental fate. A multi-method approach (including different size-measurement techniques and the DLVO theory) was used to thoroughly characterise the behaviour of iron oxide nanoparticles (Fe2O3NPs) under environmentally relevant conditions. Although recent studies have demonstrated the importance of using a multi-method approach when characterising nanoparticles, the majority of current studies continue to use a single-method approach. Under some soil conditions (i.e. pH 7, 10 mM NaCl and 2 mM CaCl2) and increasing particle concentration, Fe2O3NPs underwent extensive aggregation to form large aggregates (>1 μm). Coating the nanoparticles with dissolved organic matter (DOM) was investigated as an alternative "green" solution to overcoming the aggregation issue instead of using the more commonly proposed polyelectrolytes. At high concentrations, DOM effectively covered the surface of the Fe2O3NPs, thereby conferring negative surface charge on the particles across a wide range of pH values. This provided electrostatic stabilisation and considerably reduced the particle aggregation effect. DOM-coated Fe2O3NPs also proved to be more stable under high ionic strength conditions. The presence of CaCl2, however, even at low concentrations, induced the aggregation of DOM-coated Fe2O3NPs, mainly via charge neutralisation and bridging. This has significant implications in regards to the reactivity and fate of these materials in the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Circulating and Brain BDNF Levels in Stroke Rats. Relevance to Clinical Studies

    PubMed Central

    Béjot, Yannick; Mossiat, Claude; Giroud, Maurice; Prigent-Tessier, Anne; Marie, Christine

    2011-01-01

    Background Whereas brain-derived neurotrophic factor (BDNF) levels are measured in the brain in animal models of stroke, neurotrophin levels in stroke patients are measured in plasma or serum samples. The present study was designed to investigate the meaning of circulating BDNF levels in stroke patients. Methods and Results Unilateral ischemic stroke was induced in rats by the injection of various numbers of microspheres into the carotid circulation in order to mimic the different degrees of stroke severity observed in stroke patients. Blood was serially collected from the jugular vein before and after (4 h, 24 h and 8 d) embolization and the whole brains were collected at 4, 24 h and 8 d post-embolization. Rats were then selected from their degree of embolization, so that the distribution of stroke severity in the rats at the different time points was large but similar. Using ELISA tests, BDNF levels were measured in plasma, serum and brain of selected rats. Whereas plasma and serum BDNF levels were not changed by stroke, stroke induced an increase in brain BDNF levels at 4 h and 24 h post-embolization, which was not correlated with stroke severity. Individual plasma BDNF levels did not correlate with brain levels at any time point after stroke but a positive correlation (r = 0.67) was observed between individual plasma BDNF levels and stroke severity at 4 h post-embolization. Conclusion Circulating BDNF levels do not mirror brain BDNF levels after stroke, and severe stroke is associated with high plasma BDNF in the very acute stage. PMID:22195050

  17. Burial Level Change Defines a High Energetic Relevance for Protein Binding Interfaces.

    PubMed

    Li, Zhenhua; He, Ying; Wong, Limsoon; Li, Jinyan

    2015-01-01

    Protein-protein interfaces defined through atomic contact or solvent accessibility change are widely adopted in structural biology studies. But, these definitions cannot precisely capture energetically important regions at protein interfaces. The burial depth of an atom in a protein is related to the atom's energy. This work investigates how closely the change in burial level of an atom/residue upon complexation is related to the binding. Burial level change is different from burial level itself. An atom deeply buried in a monomer with a high burial level may not change its burial level after an interaction and it may have little burial level change. We hypothesize that an interface is a region of residues all undergoing burial level changes after interaction. By this definition, an interface can be decomposed into an onion-like structure according to the burial level change extent. We found that our defined interfaces cover energetically important residues more precisely, and that the binding free energy of an interface is distributed progressively from the outermost layer to the core. These observations are used to predict binding hot spots. Our approach's F-measure performance on a benchmark dataset of alanine mutagenesis residues is much superior or similar to those by complicated energy modeling or machine learning approaches.

  18. Ultra Low Level Environmental Neutron Measurements Using Superheated Droplet Detectors

    SciTech Connect

    Fernandes, A.C.; Felizardo, M.; Girard, T.A.; Kling, A.; Ramos, A.R.; Marques, J.G.; Prudencio, M.I.; Marques, R.; Carvalho, F.P.

    2015-07-01

    Through the application of superheated droplet detectors (SDDs), the SIMPLE project for the direct search for dark matter (DM) reached the most restrictive limits on the spin-dependent sector to date. The experiment is based on the detection of recoils following WIMP-nuclei interaction, mimicking those from neutron scattering. The thermodynamic operation conditions yield the SDDs intrinsically insensitive to radiations with linear energy transfer below ∼150 keVμm{sup -1} such as photons, electrons, muons and neutrons with energies below ∼40 keV. Underground facilities are increasingly employed for measurements in a low-level radiation background (DM search, gamma-spectroscopy, intrinsic soft-error rate measurements, etc.), where the rock overburden shields against cosmic radiation. In this environment the SDDs are sensitive only to α-particles and neutrons naturally emitted from the surrounding materials. Recently developed signal analysis techniques allow discrimination between neutron and α-induced signals. SDDs are therefore a promising instrument for low-level neutron and α measurements, namely environmental neutron measurements and α-contamination assays. In this work neutron measurements performed in the challenging conditions of the latest SIMPLE experiment (1500 mwe depth with 50-75 cm water shield) are reported. The results are compared with those obtained by detailed Monte Carlo simulations of the neutron background induced by {sup 238}U and {sup 232}Th traces in the facility, shielding and detector materials. Calculations of the neutron energy distribution yield the following neutron fluence rates (in 10{sup -8} cm{sup -2}s{sup -1}): thermal (<0.5 eV): 2.5; epithermal (0.5 eV-100 keV): 2.2; fast (>1 MeV): 3.9. Signal rates were derived using standard cross sections and codes routinely employed in reactor dosimetry. The measured and calculated neutron count rates per unit of active mass were 0.15 ct/kgd and 0.33 ct/kg-d respectively. As the major

  19. Low-level (submicromole) environmental 14C metrology

    NASA Astrophysics Data System (ADS)

    Currie, L. A.; Kessler, J. D.; Marolf, J. V.; McNichol, A. P.; Stuart, D. R.; Donoghue, J. C.; Donahue, D. J.; Burr, G. S.; Biddulph, D.

    2000-10-01

    Accelerator mass spectrometry (AMS) measurements of environmental 14C have been employed during the past decade at the several micromole level (tens of μg carbon), but advanced research in the atmospheric and marine sciences demands still higher (μg) sensitivity, an extreme example being the determination of 14C in elemental or "black" carbon (BC) at levels of 2-10 μg per kg of Greenland snow and ice (Currie et al., 1998). A fundamental limitation for 14C AMS is Poisson counting statistics, which sets in at about 1 μg modern-C. Using the small sample (25 μg) AMS target preparation facility at NOSAMS (Pearson et al., 1998), and the microsample combustion-dilution facility at NIST, we have demonstrated an intrinsic modern-C quantification limit ( mQ) of ca. 0.9 μg, based on a 1-parameter fit to the empirical AMS variance function. (For environmental 14C, the modern carbon quantification limit is defined as that mass ( mQ) corresponding to 10% relative standard deviation (rsd) for the fraction of modern carbon, σ( fM)/ fM.) Stringent control, required for quantitative dilution factors (DL), is achieved with the NIST on-line manometric/mass spectrometry facility that compensates also for unsuspected trace impurities from vigorous chemical processing (e.g., acid digestion). Our current combustion blank is trivial (mean: 0.16 ± 0.02 μg C, n=13) but lognormally distributed (dispersion [σ]: 0.07 ± 0.01 μg). An iterative numerical expression is introduced to assess the quantitative impacts of fossil and modern carbon blank components on mQ; and a new "clean chemistry" BC processing system is described for the minimization of such blanks. For the assay of soot carbon in Greenland snow/ice, the overall processing blank has been reduced from nearly 7 μg total carbon to less than 1 μg, and is undetectable for BC.

  20. [Characteristics of blood lipids levels and relevant factor analysis during pregnancy].

    PubMed

    Jiang, H Q; Chen, H; Yang, J

    2016-03-08

    To study the characteristics of blood lipids levels' change during pregnancy, and to discuss the relationships between the blood lipid level and the age, gestational hypertension, gestational diabetes and other pregnancy complications. From January to September 2015, we enrolled 2 907 pregnant women admitted to our hospital for regular checks as control group, 190 cases in gestational hypertension group, 258 cases in gestational diabetes mellitus group. The control group was divided into first trimester (≤12 w) second trimester (20 to 26 w) and third trimester (≥28 w) groups; in second trimester group, patients were further divided into the certain age group (<35years old) and elderly group (≥35 years old); blood lipid levels including serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) were detected in all groups. (1) Blood lipids levels varied as pregnancy proceeded. TG level increased most significantly, followed by TC, LDL-C level. However, HDL-C level slightly decreased in third trimester comparing with first and second trimester stage, the difference was statistically significant (P< 0.05); (2) serum TC, TG and LDL-C level in second trimester were significantly higher in the certain age group than in the elder group (P< 0.05); (3) in gestational diabetes mellitus group, serum TC, TG, LDL-C levels were significantly higher in first and second trimester than those in the control group (P< 0.05); (4) in gestational hypertension group, serum TC, TG, LDL-C levels were significantly higher in third trimester than those in the control group (P< 0.05); HDL-C level was lower in the gestational hypertension group than in the control group, and there was statistically significant difference (P<0.05). The blood lipid levels in pregnancy increase gradually as the gestational weeks increase, which can be explained as a normal physiological phenomenon. Elder pregnancy

  1. Ecologically relevant levels of multiple, common marine stressors suggest antagonistic effects.

    PubMed

    Lange, Rolanda; Marshall, Dustin

    2017-07-24

    Stressors associated with global change will be experienced simultaneously and may act synergistically, so attempts to estimate the capacity of marine systems to cope with global change requires a multi-stressor approach. Because recent evidence suggests that stressor effects can be context-dependent, estimates of how stressors are experienced in ecologically realistic settings will be particularly valuable. To enhance our understanding of the interplay between environmental effects and the impact of multiple stressors from both natural and anthropogenic sources, we conducted a field experiment. We explored the impact of multiple, functionally varied stressors from both natural and anthropogenic sources experienced during early life history in a common sessile marine invertebrate, Bugula neritina. Natural spatial environmental variation induced differences in conspecific densities, allowing us to test for density-driven context-dependence of stressor effects. We indeed found density-dependent effects. Under high conspecific density, individual survival increased, which offset part of the negative effects of experiencing stressors. Experiencing multiple stressors early in life history translated to a decreased survival in the field, albeit the effects were not as drastic as we expected: our results are congruent with antagonistic stressor effects. We speculate that when individual stressors are more subtle, stressor synergies become less common.

  2. Measurement and evaluation of the environmental noise levels in the urban areas of the city of Nis (Serbia).

    PubMed

    Prascevic, Momir R; Mihajlov, Darko I; Cvetkovic, Dragan S

    2014-02-01

    The environmental noise level represents one of the key factors of life quality in urban areas of modern cities. A continuous monitoring of the noise levels and the analysis of results have become a necessity when we discuss a possible recovery of those areas with high levels of noise pollution, and particularly, those zones which were designed for specific activities, e.g., areas around hospitals and schools. The city of Nis, Serbia, owing to the permanent long-term noise monitoring, possesses a database containing figures related to the noise levels at relevant locations in the city, which can serve as a basis for an analysis of the change of conditions, their tendencies in the future, and recognizing factors which influence the danger of noise pollution. The paper involves an analysis of the environmental noise level collected during the previous years.

  3. Immunosuppressive effects and associated compensatory responses in zebrafish after full life-cycle exposure to environmentally relevant concentrations of cadmium.

    PubMed

    Guo, Sai-Nan; Zheng, Jia-Lang; Yuan, Shuang-Shuang; Zhu, Qing-Ling; Wu, Chang-Wen

    2017-07-01

    In natural environments, fish survive in polluted water by cadmium (Cd) throughout their whole life cycle. However, little information is available on Cd toxicity considering a life cycle assessment. The present study investigated effects of environmental levels of cadmium (0, 2.5, and 5μg/L) on immune responses in liver and spleen of zebrafish for 15 weeks, from embryos to sexually maturity. Nitric oxide (NO) levels and iNOS activity declined in liver and spleen of zebrafish exposed to 5μg/L Cd, suggesting an immunosuppressive effect. The result was further supported by the decreased transcriptional levels of proinflammatory cytokines by Cd, such as interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-1β (IL-1β), and tumour necrosis factor-α (TNF-α) in liver. However, a sharp increase in the mRNA levels of these cytokines was observed in spleen of zebrafish exposed to Cd. The increased mRNA expression of these proinflammatory cytokines may be the secondary effect following immunosuppression and just reflect a compensatory mechanism for coping with the decreased immunity, which may explain an increase in mRNA levels and a decrease in iNOS activity in spleen of zebrafish exposed to Cd. In liver, the down-regulated mRNA levels of iNOS paralleled with the decreased iNOS activity, suggesting a synchronous response from a molecular level to a biochemical level. Positive correlations between mRNA expression levels of nuclear transcription factor κB (NF-κB) and proinflammatory cytokines were also observed, suggesting that NF-κB might be required for the protracted induction of inflammatory genes. The corresponding changes in the mRNA levels of the inhibitor of κBα (IκBαa and IκBαb) may form a feedback loop to restore transcriptional activity of NF-κB. Furthermore, splenic ROS levels were increased by 5μg/L Cd, possibly activating NF-κB pathway. Taken together, immunosuppressive effects and tissue-dependent compensatory responses were demonstrated in

  4. Remote sensing of landscape-level coastal environmental indicators.

    PubMed

    Klemas, V V

    2001-01-01

    Advances in technology and decreases in cost are making remote sensing (RS) and geographic information systems (GIS) practical and attractive for use in coastal resource management. They are also allowing researchers and managers to take a broader view of ecological patterns and processes. Landscape-level environmental indicators that can be detected by Landsat Thematic Mapper (TM) and other remote sensors are available to provide quantitative estimates of coastal and estuarine habitat conditions and trends. Such indicators include watershed land cover, riparian buffers, shoreline and wetland changes, among others. With the launch of Landsat 7, the cost of TM imagery has dropped by nearly a factor of 10, decreasing the cost of monitoring large coastal areas and estuaries. New satellites, carrying sensors with much finer spatial (1-5 m) and spectral (200 narrow bands) resolutions are being launched, providing a capability to more accurately detect changes in coastal habitat and wetland health. Advances in the application of GIS help incorporate ancillary data layers to improve the accuracy of satellite land-cover classification. When these techniques for generating, organizing, storing, and analyzing spatial information are combined with mathematical models, coastal planners and managers have a means for assessing the impacts of alternative management practices.

  5. Chronic exposure to environmental levels of tribromophenol impairs zebrafish reproduction

    SciTech Connect

    Deng Jun; Liu Chunsheng; Yu Liqin; Zhou Bingsheng

    2010-02-15

    Tribromophenol (2,4,6-TBP) is ubiquitously found in aquatic environments and biota. In this study, we exposed zebrafish embryos (F{sub 0}; 2'''' days post-fertilization, dpf) to environmental concentration (0.3 mug/L) and a higher concentration (3.0 mug/L) of TBP and assessed the impact of chronic exposure (120 dpf) on reproduction. TBP exposure did not cause a significant increase in the malformation and reduction in the survival in the F{sub 0}-generation fish. After TBP exposure, the plasma testosterone and estradiol levels significantly increased in males and decreased in females. The transcription of steroidogenic genes (3beta-HSD, 17beta-HSD, CYP17, CYP19A, CYP19B) was significantly upregulated in the brain and testes in males and downregulated in the brain and ovary in females. TBP exposure significantly downregulated and upregulated the expression of VTG in the liver of female and male fish, respectively. Meanwhile, TBP exposure altered the sex ratio toward a male-dominant state. The F{sub 1}-generation larvae exhibited increased malformation, reduced survival, and retarded growth, suggesting that TBP in the aquatic environment has significant adverse effects on fish population.

  6. Level of environmental threat posed by horticultural trade in Cactaceae.

    PubMed

    Novoa, Ana; Le Roux, Johannes J; Richardson, David M; Wilson, John R U

    2017-10-01

    Ornamental horticulture has been identified as an important threat to plant biodiversity and is a major pathway for plant invasions worldwide. In this context, the family Cactaceae is particularly challenging because it is considered the fifth most threatened large taxonomic group in the world; several species are among the most widespread and damaging invasive species; and Cactaceae is one of the most popular horticultural plant groups. Based on the Convention on International Trade in Endangered Species of Wild Flora and Fauna and the 11 largest online auction sites selling cacti, we documented the international cactus trade. To provide an in-depth look at the dynamics of the industry, we surveyed the businesses involved in the cactus trade in South Africa (a hotspot of cactus trade and invasions). We purchased seeds of every available species and used DNA barcoding to identify species to the genus level. Although <20% of this trade involved threatened species and <3% involved known invasive species, many species were identified by a common name. However, only 0.02% of the globally traded cacti were collected from wild populations. Despite a large commercial network, all South African imports (of which 15% and 1.5% were of species listed as threatened and invasive, respectively) came from the same source. With DNA barcoding, we identified 24% of the species to genus level. Based on our results, we believe that if trade restrictions are placed on the small proportion of cacti that are invasive and there is no major increase in harvesting of native populations, then the commercial trade in cactus poses a negligible environmental threat. However, there are currently no effective methods for easily identifying which cacti are traded, and both the illicit harvesting of cacti from the wild and the informal trade in invasive taxa pose on-going conservation challenges. © 2017 Society for Conservation Biology.

  7. A Study on Environmental Knowledge Level of Primary Students in Turkey

    ERIC Educational Resources Information Center

    Gökdere, Murat

    2005-01-01

    The education system in Turkey has responded promptly to the need for environmental education (EE). However, the existing lack of relevant research may limit the functionality of EE programs in Turkey. In this study, the goal was to develop an environmental conscious database that would allow effective planning of EE. Specifically, the study was…

  8. A Study on Environmental Knowledge Level of Primary Students in Turkey

    ERIC Educational Resources Information Center

    Gökdere, Murat

    2005-01-01

    The education system in Turkey has responded promptly to the need for environmental education (EE). However, the existing lack of relevant research may limit the functionality of EE programs in Turkey. In this study, the goal was to develop an environmental conscious database that would allow effective planning of EE. Specifically, the study was…

  9. Relevance of Education and Intelligence at the National Level for the Economic Welfare of People

    ERIC Educational Resources Information Center

    Rindermann, Heiner

    2008-01-01

    Cognitive abilities are important for the economic and non-economic success of individuals and societies. For international analyses, the collection of IQ-measures from Lynn and Vanhanen was supplemented and meliorated by data from international student assessment studies (IEA-Reading, TIMSS, PISA, PIRLS). The cognitive level of a nation is highly…

  10. Relevance of Education and Intelligence at the National Level for the Economic Welfare of People

    ERIC Educational Resources Information Center

    Rindermann, Heiner

    2008-01-01

    Cognitive abilities are important for the economic and non-economic success of individuals and societies. For international analyses, the collection of IQ-measures from Lynn and Vanhanen was supplemented and meliorated by data from international student assessment studies (IEA-Reading, TIMSS, PISA, PIRLS). The cognitive level of a nation is highly…

  11. Structural characterization of environmentally relevant ternary uranyl citrate complexes present in aqueous solutions and solid state materials.

    PubMed

    Basile, Madeline; Unruh, Daniel K; Flores, Erin; Johns, Adam; Forbes, Tori Z

    2015-02-14

    Organic acids are important metal chelators in environmental systems and tend to form soluble complexes in aqueous solutions, ultimately influencing the transport and bioavailability of contaminants in surface and subsurface waters. This is particularly true for the formation of uranyl citrate complexes, which have been utilized in advanced photo- and bioremediation strategies for soils contaminated with nuclear materials. Given the complexity of environmental systems, the formation of ternary or heterometallic uranyl species in aqueous solutions are also expected, particularly with Al(iii) and Fe(iii) cations. These ternary forms are reported to be more stable in aqueous solutions, potentially enhancing contaminant mobility and uptake by organisms, but the exact coordination geometries of these soluble molecular complexes have not been elucidated. To provide insight into the nature of these species, we have developed a series of geochemical model compounds ([(UO(2))(2)Al(2)(C(6)H(4)O(7))(4)](6-) (U(2)Al(2)), [(UO(2))(2)Fe(2)(C(6)H(4)O(7))(4)](6-) (U(2)Fe(2)-1) and [(UO(2))(2)Fe(2)(C(6)H(4)O(7))(4)(H(2)O)(2)](6-) (U(2)Fe(2)-2) and [(UO(2))(2)Fe(4)(OH)(4)(C(6)H(4)O(7))(4)](8-) (U(2)Fe(4))) that were characterized by single-crystal X-ray diffraction and vibrational spectroscopy. Mass spectroscopy was then employed to compare the model compounds to species present in aqueous solutions to provide an enhanced understanding of the ternary uranyl citrate complexes that could be relevant in natural systems.

  12. Quantitative analysis of receptor tyrosine kinase-effector coupling at functionally relevant stimulus levels.

    PubMed

    Li, Simin; Bhave, Devayani; Chow, Jennifer M; Riera, Thomas V; Schlee, Sandra; Rauch, Simone; Atanasova, Mariya; Cate, Richard L; Whitty, Adrian

    2015-04-17

    A major goal of current signaling research is to develop a quantitative understanding of how receptor activation is coupled to downstream signaling events and to functional cellular responses. Here, we measure how activation of the RET receptor tyrosine kinase on mouse neuroblastoma cells by the neurotrophin artemin (ART) is quantitatively coupled to key downstream effectors. We show that the efficiency of RET coupling to ERK and Akt depends strongly on ART concentration, and it is highest at the low (∼100 pM) ART levels required for neurite outgrowth. Quantitative discrimination between ERK and Akt pathway signaling similarly is highest at this low ART concentration. Stimulation of the cells with 100 pM ART activated RET at the rate of ∼10 molecules/cell/min, leading at 5-10 min to a transient peak of ∼150 phospho-ERK (pERK) molecules and ∼50 pAkt molecules per pRET, after which time the levels of these two signaling effectors fell by 25-50% while the pRET levels continued to slowly rise. Kinetic experiments showed that signaling effectors in different pathways respond to RET activation with different lag times, such that the balance of signal flux among the different pathways evolves over time. Our results illustrate that measurements using high, super-physiological growth factor levels can be misleading about quantitative features of receptor signaling. We propose a quantitative model describing how receptor-effector coupling efficiency links signal amplification to signal sensitization between receptor and effector, thereby providing insight into design principles underlying how receptors and their associated signaling machinery decode an extracellular signal to trigger a functional cellular outcome.

  13. Quantitative Analysis of Receptor Tyrosine Kinase-Effector Coupling at Functionally Relevant Stimulus Levels*♦

    PubMed Central

    Li, Simin; Bhave, Devayani; Chow, Jennifer M.; Riera, Thomas V.; Schlee, Sandra; Rauch, Simone; Atanasova, Mariya; Cate, Richard L.; Whitty, Adrian

    2015-01-01

    A major goal of current signaling research is to develop a quantitative understanding of how receptor activation is coupled to downstream signaling events and to functional cellular responses. Here, we measure how activation of the RET receptor tyrosine kinase on mouse neuroblastoma cells by the neurotrophin artemin (ART) is quantitatively coupled to key downstream effectors. We show that the efficiency of RET coupling to ERK and Akt depends strongly on ART concentration, and it is highest at the low (∼100 pm) ART levels required for neurite outgrowth. Quantitative discrimination between ERK and Akt pathway signaling similarly is highest at this low ART concentration. Stimulation of the cells with 100 pm ART activated RET at the rate of ∼10 molecules/cell/min, leading at 5–10 min to a transient peak of ∼150 phospho-ERK (pERK) molecules and ∼50 pAkt molecules per pRET, after which time the levels of these two signaling effectors fell by 25–50% while the pRET levels continued to slowly rise. Kinetic experiments showed that signaling effectors in different pathways respond to RET activation with different lag times, such that the balance of signal flux among the different pathways evolves over time. Our results illustrate that measurements using high, super-physiological growth factor levels can be misleading about quantitative features of receptor signaling. We propose a quantitative model describing how receptor-effector coupling efficiency links signal amplification to signal sensitization between receptor and effector, thereby providing insight into design principles underlying how receptors and their associated signaling machinery decode an extracellular signal to trigger a functional cellular outcome. PMID:25635057

  14. POPTOX: Population-level responses of an amphipod to contaminated marine sediments and other environmental stresses

    SciTech Connect

    DeWitt, T.H. |

    1994-12-31

    Experimental measurements of population-level responses are useful to environmental management in two ways: (1) to estimate the fitness of populations in an ecological-risk study, and (2) to evaluate the ecological relevance of shorter-term acute and chronic toxicity tests that use the same test species. An experimental system was developed for modeling the population-level responses of the burrowing, estuarine amphipod, Leptocheirus plumulosus, to environmental stresses, including chemical contamination. Replicate cohorts of newborn amphipods were exposed to natural and anthropogenic (PAH-contaminated sediment) stresses under static-renewal conditions over periods varying up to their full life-span. The amphipods were periodically removed from the sediment, censused, measured, and returned alive to the exposure chamber; the resulting life-history data were used to develop age-based, matrix-algebraic, population-projection models. Preliminary experiments revealed that an exposure period of 12 weeks with a sampling frequency of 2 weeks was sufficient to model the population dynamics of this amphipod. This experimental system may also be,used to study the interaction between anthropogenic stresses and ecological stresses under controlled and long-term exposures.

  15. Cork stoppers as an effective sorbent for water treatment: the removal of mercury at environmentally relevant concentrations and conditions.

    PubMed

    Lopes, Cláudia B; Oliveira, Joana R; Rocha, Luciana S; Tavares, Daniela S; Silva, Carlos M; Silva, Susana P; Hartog, Niels; Duarte, Armando C; Pereira, E

    2014-02-01

    The technical feasibility of using stopper-derived cork as an effective biosorbent towards bivalent mercury at environmentally relevant concentrations and conditions was evaluated in this study. Only 25 mg/L of cork powder was able to achieve 94 % of mercury removal for an initial mercury concentration of 500 μg/L. It was found that under the conditions tested, the efficiency of mercury removal expressed as equilibrium removal percentage does not depend on the amount of cork or its particle size, but is very sensitive to initial metal concentration, with higher removal efficiencies at higher initial concentrations. Ion exchange was identified as one of the mechanisms involved in the sorption of Hg onto cork in the absence of ionic competition. Under ionic competition, stopper-derived cork showed to be extremely effective and selective for mercury in binary mixtures, while in complex matrices like seawater, moderate inhibition of the sorption process was observed, attributed to a change in mercury speciation. The loadings achieved are similar to the majority of literature values found for other biosorbents and for other metals, suggesting that cork stoppers can be recycled as an effective biosorbent for water treatment. However, the most interesting result is that equilibrium data show a very rare behaviour, with the isotherm presenting an almost square convex shape to the concentration axis, with an infinite slope for an Hg concentration in solution around 25 μg/L.

  16. Standardized toxicity testing may underestimate ecotoxicity: Environmentally relevant food rations increase the toxicity of silver nanoparticles to Daphnia.

    PubMed

    Stevenson, Louise M; Krattenmaker, Katherine E; Johnson, Erica; Bowers, Alexandra J; Adeleye, Adeyemi S; McCauley, Edward; Nisbet, Roger M

    2017-05-29

    Daphnia in the natural environment experience fluctuations in algal food supply, with periods when algal populations bloom and seasons when Daphnia have very little algal food. Standardized chronic toxicity tests, used for ecological risk assessment, dictate that Daphnia must be fed up to 400 times more food than they would experience in the natural environment (outside of algal blooms) for a toxicity test to be valid. This disconnect can lead to underestimating the toxicity of a contaminant. We followed the growth, reproduction, and survival of Daphnia exposed to 75 and 200 µg/L silver nanoparticles (AgNPs) at 4 food rations for up to 99 d and found that AgNP exposure at low, environmentally relevant food rations increased the toxicity of AgNPs. Exposure to AgNP at low food rations decreased the survival and/or reproduction of individuals, with potential consequences for Daphnia populations (based on calculated specific population growth rates). We also found tentative evidence that a sublethal concentration of AgNPs (75 µg/L) caused Daphnia to alter energy allocation away from reproduction and toward survival and growth. The present findings emphasize the need to consider resource availability, and not just exposure, in the environment when estimating the effect of a toxicant. Environ Toxicol Chem 2017;9999:1-11. © 2017 SETAC. © 2017 SETAC.

  17. The Effect of Microplastic on the Uptake of Chemicals by the Lugworm Arenicola marina (L.) under Environmentally Relevant Exposure Conditions

    PubMed Central

    2017-01-01

    It has been hypothesized that ingestion of microplastic increases exposure of aquatic organisms to hydrophobic contaminants. To date, most laboratory studies investigated chemical transfer from ingested microplastic without taking other exposure pathways into account. Therefore, we studied the effect of polyethylene (PE) microplastic in sediment on PCB uptake by Arenicola marina as a model species, quantifying uptake fluxes from all natural exposure pathways. PCB concentrations in sediment, biota lipids (Clip) and porewater measured with passive samplers were used to derive lipid-normalized bioaccumulation metrics Clip, Biota sediment accumulation factor (BSAF), Bioaccumulation factor (BAF) and the Biota plastic accumulation factor (BPAF). Small effects of PE addition were detected suggesting slightly increased or decreased bioaccumulation. However, the differences decreased in magnitude dependent on the metric used to assess bioaccumulation, in the order: Clip > BSAF > BPAF > BAF, and were nonsignificant for BAF. The fact that BAF, that is, normalization of Clip on porewater concentration, largely removed all effects of PE, shows that PE did not act as a measurable vector of PCBs. Biodynamic model analysis confirmed that PE ingestion contributed marginally to bioaccumulation. This work confirmed model-based predictions on the limited relevance of microplastic for bioaccumulation under environmentally realistic conditions, and illustrated the importance of assessing exposure through all media in microplastic bioaccumulation studies. PMID:28682597

  18. Biological effects of environmentally relevant concentrations of the pharmaceutical Triclosan in the marine mussel Perna perna (Linnaeus, 1758).

    PubMed

    Cortez, Fernando Sanzi; Seabra Pereira, Camilo Dias; Santos, Aldo Ramos; Cesar, Augusto; Choueri, Rodrigo Brasil; Martini, Gisela de Assis; Bohrer-Morel, Maria Beatriz

    2012-09-01

    Triclosan (5-Chloro-2-(2,4-dichlorophenoxy) phenol) is an antibacterial compound widely employed in pharmaceuticals and personal care products. Although this emerging compound has been detected in aquatic environments, scarce information is found on the effects of Triclosan to marine organisms. The aim of this study was to evaluate the toxicity of a concentration range of Triclosan through fertilization assay (reproductive success), embryo-larval development assay (early life stage) and physiological stress (Neutral Red Retention Time assay - NRRT) (adult stage) in the marine sentinel organism Perna perna. The mean inhibition concentrations for fertilization (IC(50) = 0.490 mg L(-1)) and embryo-larval development (IC(50) = 0.135 mg L(-1)) tests were above environmental relevant concentrations (ng L(-1)) given by previous studies. Differently, significant reduction on NRRT results was found at 12 ng L(-1), demonstrating the current risk of the continuous introduction of Triclosan into aquatic environments, and the need of ecotoxicological studies oriented by the mechanism of action of the compound. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. DNA alterations triggered by environmentally relevant polymetallic concentrations in marine clams Ruditapes philippinarum and polychaete worms Hediste diversicolor.

    PubMed

    Dedeh, Amina; Ciutat, Aurélie; Tran, Damien; Bourdineaud, Jean-Paul

    2014-11-01

    We exposed marine clams (Ruditapes philippinarum) and aquatic worms (Hediste diversicolor) to environmentally relevant concentrations of two metal mixtures each containing three divalent metals [(C₁ in µg/L) cadmium (Cd) 1, mercury (Hg) 0.1, and lead (Pb) 4] and [C₂ in µg/L) Cd 17, Hg 1.1, and Pb 55]. Animals collected in the Arcachon Bay were exposed for 8 days in microcosms made up of a mixed biotope consisting of a water column and natural marine sediment both taken up from the Arcachon Bay. Bioaccumulation analysis showed a significant increase of Cd, Hg, and Pb in clams, particularly at C₂ concentration in the water column reaching, in soft body, 2.3 ± 0.3 µg Cd/g, 0.7 ± 0.2 µg Hg/g, and 45 µg Pb/g dry weight (dw). DNA alterations and upregulation of the cox1 mitochondrial gene were also observed in clam gill after exposure to the metal blend. For worms exposed to the C₂ metal blend, DNA alterations and significant increase of Cd and Hg concentrations were observed reaching 0.5 ± 0.1 µg Cd/g and 2 ± 0.6 µg Hg/g dw.

  20. Sublethal effects of the beta-blocker sotalol at environmentally relevant concentrations on the New Zealand mudsnail Potamopyrgus antipodarum.

    PubMed

    Feiner, Mona; Laforsch, Christian; Letzel, Thomas; Geist, Juergen

    2014-11-01

    Monitoring sublethal effects of pharmaceuticals on nontarget species in aquatic environments has become an important topic in ecotoxicology, yet few studies have been conducted concerning the effects of beta-blockers on aquatic organisms. The present study investigated the effects of the beta-blocker sotalol (SOT) at 3 environmentally relevant concentrations on life-history traits of the New Zealand mudsnail Potamopyrgus antipodarum. Based on the pharmacodynamic properties of SOT, the authors hypothesized reduced numbers of embryos in the brood pouches, decelerated growth of adult snails, and smaller size of neonates, but no effect on mortality rates of adults. Contrary to the hypothesis, the total number of embryos was significantly higher after 56 d of exposure at nominal concentrations of 0.05 µg/L and 1.0 µg/L by 107% and 73%, respectively. No differences in embryo numbers were observed at earlier time-points. Therefore, the mode of action seems to be an extension of the reproductive period rather than an increase of the embryo production. Furthermore, our results indicate a hormetic dose-response relationship, because no effects were observed at the highest test-concentration (6.5 µg/L). Mortality, growth of adult snails, and neonate sizes were not affected by the beta-blocker. Given the strong influence on reproduction, the effects of sublethal concentrations of SOT and other beta-blockers deserve better consideration in ecotoxicological risk assessment.

  1. Influence of size and aggregation on the reactivity of an environmentally and industrially relevant nanomaterial (PbS).

    PubMed

    Liu, Juan; Aruguete, Deborah M; Murayama, Mitsuhiro; Hochella, Michael F

    2009-11-01

    Rarely observed nanoparticle dissolution rate data have been collected and explained for an environmentally and industrially relevant nanomaterial (PbS, the mineral galena) as a function of its particle size and aggregation state using high-resolution transmission electron microscopy (HRTEM) and solution analysis. Under identical anoxic acidic conditions (pH 3 HCl), it has been determined that the dissolution rate of PbS galena varies by at least 1 order of magnitude simply as a function of particle size, and also due to the aggregation state of the particles (dissolution rates measured are 4.4 x 10(-9) mol m(-2) s(-1) for dispersed 14 nm nanocrystals; 7.7 x 10(-10) mol m(-2) s(-1) for dispersed 3.1 microm microcrystals; and 4.7 x 10(-10) mol m(-2) s(-1) for aggregated 14 nm nanocrystals). The dissolution rate difference between galena microparticles and nanoparticles is due to differences in nanotopography and the crystallographic faces present. Aggregate vs. dispersed dissolution rates are related to transport inhibition in the observed highly confined spaces between densely packed, aggregated nanocrystals, where self-diffusion coefficients of water and ions decrease dramatically. This study shows that factors at the nanometer scale significantly influence the release rate of aqueous, highly toxic and bioavailable Pb in natural or industrial environments during galena dissolution.

  2. Is the OECD acute worm toxicity test environmentally relevant? The effect of mineral form on calculated lead toxicity.

    PubMed

    Davies, Nicola A; Hodson, Mark E; Black, Stuart

    2003-01-01

    In a series of experiments the toxicity of lead to worms in soil was determined following the draft OECD earthworm reproduction toxicity protocol except that lead was added as solid lead nitrate, carbonate and sulphide rather than as lead nitrate solution as would normally be the case. The compounds were added to the test soil to give lead concentrations of 625-12 500 microg Pb g(-1) of soil. Calculated toxicities of the lead decreased in the order nitrate> carbonate> sulphide, the same order as the decrease in the solubility of the metal compounds used. The 7-day LC50 (lethal concentration when 50% of the population is killed) for the nitrate was 5321+/-275 microg Pb g(-1) of soil and this did not change with time. The LC50 values for carbonate and sulphide could not be determined at the concentration ranges used. The only parameter sensitive enough to distinguish the toxicities of the three compounds was cocoon (egg) production. The EC50s for cocoon production (the concentration to produce a 50% reduction in cocoon production) were 993, 8604 and 10246 pg Pb g(-1) of soil for lead nitrate, carbonate and sulphide, respectively. Standard toxicity tests need to take into account the form in which the contaminant is present in the soil to be of environmental relevance.

  3. Effects of Cd & Ni toxicity to Ceratophyllum demersum under environmentally relevant conditions in soft & hard water including a German lake.

    PubMed

    Andresen, Elisa; Opitz, Judith; Thomas, George; Stärk, Hans-Joachim; Dienemann, Holger; Jenemann, Kerstin; Dickinson, Bryan C; Küpper, Hendrik

    2013-10-15

    Even essential trace elements are phytotoxic over a certain threshold. In this study, we investigated whether heavy metal concentrations were responsible for the nearly complete lack of submerged macrophytes in an oligotrophic lake in Germany. We cultivated the rootless aquatic model plant Ceratophyllum demersum under environmentally relevant conditions like sinusoidal light and temperature cycles and a low plant biomass to water volume ratio. Experiments lasted for six weeks and were analysed by detailed measurements of photosynthetic biophysics, pigment content and hydrogen peroxide production. We established that individually non-toxic cadmium (3 nM) and slightly toxic nickel (300 nM) concentrations became highly toxic when applied together in soft water, severely inhibiting photosynthetic light reactions. Toxicity was further enhanced by phosphate limitation (75 nM) in soft water as present in many freshwater habitats. In the investigated lake, however, high water hardness limited the toxicity of these metal concentrations, thus the inhibition of macrophytic growth in the lake must have additional reasons. The results showed that synergistic heavy metal toxicity may change ecosystems in many more cases than estimated so far. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Different biosorption mechanisms of Uranium(VI) by live and heat-killed Saccharomyces cerevisiae under environmentally relevant conditions.

    PubMed

    Wang, Tieshan; Zheng, Xinyan; Wang, Xiaoyu; Lu, Xia; Shen, Yanghao

    2017-02-01

    Uranium adsorption mechanisms of live and heat-killed Saccharomyces cerevisiae in different pH values and biomass concentrations were studied under environmentally relevant conditions. Compared with live cells, the adsorption capacity of heat-killed cells is almost one order of magnitude higher in low biomass concentration and highly acidic pH conditions. To explore the mesoscopic surface interactions between uranium and cells, the characteristic of uranium deposition was investigated by SEM-EDX, XPS and FTIR. Biosorption process of live cells was considered to be metabolism-dependent. Under stimulation by uranyl ions, live cells could gradually release phosphorus and reduce uranium from U(VI) to U(IV) to alleviate uranium toxicity. The uranyl-phosphate complexes were formed in scale-like shapes on cell surface. The metabolic detoxification mechanisms such as reduction and "self-protection" are of significance to the migration of radionuclides. In the metabolism-independent biosorption process of heat-killed cells: the cells cytomembrane was damaged by autoclaving which led to the free diffusion of phosphorous from intracellular, and the rough surface and nano-holes indicated that the dead cells provided larger contact area to precipitate U(VI) as spherical nano-particles. The high biosorption capacity of heat-killed cells makes it become a suitable biological adsorbent for uranium removal.

  5. Environmentally Relevant Concentrations of Atrazine and Ametrine Induce Micronuclei Formation and Nuclear Abnormalities in Erythrocytes of Fish.

    PubMed

    Botelho, R G; Monteiro, S H; Christofoletti, C A; Moura-Andrade, G C R; Tornisielo, V L

    2015-11-01

    A rapid and sensitive method using liquid chromatography coupled with mass spectrometry triple quadrupole direct aqueous injection for analysis of atrazine and ametrine herbicides in surface waters was developed. According to the validation method, water samples from six different locations in the Piracicaba River were collected monthly from February 2011 to January 2012 and injected into a liquid chromatographer/dual mass spectrometer without the need for sample extraction. The method was validated and shown to be precise and accurate; limits of detection and quantification were 0.07 and 0.10 µg L(-1) for atrazine and 0.09 and 0.14 µg L(-1) for ametrine. During the sampling period, concentrations of atrazine ranged from 0.11 to 1.92 µg L(-1) and ametrine from 0.25 to 1.44 µg L(-1). After analysis of the herbicides, Danio rerio were exposed a range of concentrations found in the river water to check the induction of micronuclei and nuclear abnormalities (NAs) in erythrocytes. Concentrations of atrazine and ametrine >1.0 and 1.5 µg L(-1), respectively, induced MN formation in D. rerio. Ametrine was shown to be more genotoxic to D. rerio because a greater incidence of NAs was observed compared with atrazine. Therefore, environmentally relevant concentrations of atrazine and ametrine found in the Piracicaba River are dangerous to the aquatic biota.

  6. Environmentally relevant concentrations of DE-71 and HBCD alter eggshell thickness and reproductive success of American kestrels.

    PubMed

    Fernie, Kim J; Shutt, J Laird; Letcher, Robert J; Ritchie, Ian J; Bird, David M

    2009-03-15

    Polybrominated diphenyl ethers (PBDEs) and total alpha-hexabromocyclododecane (HBCD) are flame-retardant additives that are commonly used in household and commercial applications. PBDE congeners, which are comprised of technical mixtures such as DE-71, are globally persistent and their concentrations are increasing in many species. Captive American kestrels (Falco sparverius) were exposed by diet to vehicle (safflower oil), or one of two environmentally relevant concentrations of DE-71 and unintentionally to HBCD. This exposure resulted in the birds laying eggs that contain PBDE and HBCD concentrations currently found in wild herring gull (Larus argentatus) and peregrine falcon (F. peregrinus) eggs, and compared to control kestrels, resulted in delayed egg laying and smaller eggs being laid, caused thinner eggshells and differential weight loss during embryonic development, and reduced fertility and reproductive success. The thickness of the eggshell declined as the concentrations of all measured PBDE and the total amount of a-HBCD congeners (except BDE-183 and BDE-209) increased; increasing concentrations of BDE-153, BDE-154, BDE-28, BDE-17, delayed egg laying, reduced eggshell mass (plus sigmaPBDEs), and reduced fledging success (BDE-153 and BDE-154 only). BDE-153 is the dominant congener recently found in peregrine eggs. The results of this study are consistent with the PBDE-associated brood reduction in wild European peregrines and may partially explain the decline of kestrels in North America.

  7. The Effects of Mothers' Educational Levels on University Students' Environmental Protection Commitments and Environmental Behaviors

    ERIC Educational Resources Information Center

    Saraçli, Sinan; Yilmaz, Veysel; Arslan, Talha

    2014-01-01

    Problem Statement: The damage caused by recent environmental problems has led to increased environmental concerns and the development of environment-friendly consumption behaviours in almost every society. Environment-friendly consumption involves the consideration of environmental benefits by minimizing any damage done to the environment at all…

  8. Inland waterway ports nodal attraction indices relevant in development strategies on regional level

    NASA Astrophysics Data System (ADS)

    Dinu, O.; Burciu, Ş.; Oprea, C.; Ilie, A.; Rosca, M.

    2016-08-01

    Present paper aims to propose a set of ranking indices and related criteria, concerning mainly spatial analysis, for the inland waterway port, with special view on inland ports of Danube. Commonly, the attraction potential of a certain transport node is assessed by its spatial accessibility indices considering both spatial features of the location provided by the networks that connect into that node and its economic potential defining the level of traffic flows depending on the economic centers of its hinterland. Paper starts with a overview of the critical needs that are required for potential sites to become inland waterway ports and presents nodal functions that coexist at different levels, leading to a port hierarchy from the points of view of: capacity, connection to hinterland, traffic structure and volume. After a brief review of the key inland waterway port ranking criterion, a selection of nodal attraction measures is made. Particular considerations for the Danube inland port case follows proposed methodology concerning indices of performance for network scale and centrality. As expected, the shorter the distance from an inland port to the nearest access point the greater accessibility. Major differences in ranking, dependent on selected criterion, were registered.

  9. Environmental Radioxenon Levels in Europe: a Comprehensive Overview

    NASA Astrophysics Data System (ADS)

    Saey, Paul R. J.; Schlosser, Clemens; Achim, Pascal; Auer, Matthias; Axelsson, Anders; Becker, Andreas; Blanchard, Xavier; Brachet, Guy; Cella, Luis; de Geer, Lars-Erik; Kalinowski, Martin B.; Le Petit, Gilbert; Peterson, Jenny; Popov, Vladimir; Popov, Yury; Ringbom, Anders; Sartorius, Hartmut; Taffary, Thomas; Zähringer, Matthias

    2010-05-01

    Activity concentration data from ambient radioxenon measurements in ground level air, which were carried out in Europe in the framework of the International Noble Gas Experiment (INGE) in support of the development and build-up of a radioxenon monitoring network for the Comprehensive Nuclear-Test-Ban Treaty verification regime are presented and discussed. Six measurement stations provided data from 5 years of measurements performed between 2003 and 2008: Longyearbyen (Spitsbergen, Norway), Stockholm (Sweden), Dubna (Russian Federation), Schauinsland Mountain (Germany), Bruyères-le-Châtel and Marseille (both France). The noble gas systems used within the INGE are designed to continuously measure low concentrations of the four radioxenon isotopes which are most relevant for detection of nuclear explosions: 131mXe, 133mXe, 133Xe and 135Xe with a time resolution less than or equal to 24 h and a minimum detectable concentration of 133Xe less than 1 mBq/m3. This European cluster of six stations is particularly interesting because it is highly influenced by a high density of nuclear power reactors and some radiopharmaceutical production facilities. The activity concentrations at the European INGE stations are studied to characterise the influence of civilian releases, to be able to distinguish them from possible nuclear explosions. It was found that the mean activity concentration of the most frequently detected isotope, 133Xe, was 5-20 mBq/m3 within Central Europe where most nuclear installations are situated (Bruyères-le-Châtel and Schauinsland), 1.4-2.4 mBq/m3 just outside that region (Stockholm, Dubna and Marseille) and 0.2 mBq/m3 in the remote polar station of Spitsbergen. No seasonal trends could be observed from the data. Two interesting events have been examined and their source regions have been identified using atmospheric backtracking methods that deploy Lagrangian particle dispersion modelling and inversion techniques. The results are consistent with known

  10. Developmental and lactational exposure to environmentally relevant concentrations of dieldrin does not alter pregnancy outcome and mammary gland morphology in BALB/c mice.

    PubMed

    Foster, Warren G; Mirshokraei, Pezhman; Holloway, Alison C; Zhang, Bingjun

    2008-09-01

    The objectives of this study were to: (1) determine the dosing range necessary to produce serum levels of dieldrin in mice representative of human body burdens; and (2) define the effect of developmental exposure to environmentally relevant concentrations of dieldrin on mammary gland development. Sexually mature female BALB/c mice (n=140) were randomly assigned to receive vehicle, 0.45, 2.25, 4.5, and 22.5 microg dieldrin/g body weight (BW)/day. Serum levels of dieldrin were quantified by gas chromatography in pooled samples (n=4/treatment group). Target levels of 10-30 ng/ml were achieved in 0.45 and 2.25 microg/g dose groups by the end of 2 weeks of treatment. Vehicle or dieldrin (0.45, 2.25, and 4.5 microg/g BW) was administered weekly to sexually mature female BALB/c mice (n=48) throughout mating, pregnancy, and lactation. Treatments had no effect on fertility parameters in dams or mammary gland morphology at sexual maturity. Developmental exposure to dieldrin has no effect on mammary gland development in aged BALB/c mice.

  11. Measuring parvalbumin levels in fish muscle tissue: relevance of muscle locations and storage conditions.

    PubMed

    Lee, Poi-Wah; Nordlee, Julie A; Koppelman, Stef J; Baumert, Joseph L; Taylor, Steve L

    2012-11-15

    Fish is an allergenic food capable of provoking severe anaphylactic reactions. Parvalbumin is the major allergen identified in fish and frog muscles. Antibodies against fish and frog parvalbumin have been used to quantify parvalbumin levels from fish. However, these antibodies react variably with parvalbumin from different fish species. Several factors might be responsible for this variation including instability of parvalbumin in fish muscle as a result of frozen storage and differential parvalbumin expression in muscles from various locations within the whole fish. We aimed to investigate whether these factors contribute to the previously observed variable immunoreactivity of the anti-parvalbumin antibodies. Results showed the detection of parvalbumin by these antibodies was unaffected by frozen storage of muscles for 112 days. However, the parvalbumin content decreased in fish muscles from anterior to posterior positions. This factor may partially explain for the inconsistent reactivity of anti-parvalbumin antibodies to different fish species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. [Low level of physical fitness in Spanish adolescents. Relevance for future cardiovascular health (AVENA study)].

    PubMed

    Ortega, Francisco B; Ruiz, Jonatan R; Castillo, Manuel J; Moreno, Luis A; González-Gross, Marcela; Wärnberg, Julia; Gutiérrez, Angel

    2005-08-01

    Several studies have demonstrated that physical fitness in childhood and adolescence is related to cardiovascular risk in adulthood. Current data on the physical fitness of Spanish adolescents are not available. Therefore, the aims of this study were: a) to assess the physical fitness of Spanish adolescents and establish reference values for use in health and educational settings as indicators of cardiovascular health, and b) to determine the percentage of Spanish adolescents below the minimum level of aerobic fitness needed to guarantee future cardiovascular health. The modified EUROFIT battery of tests was used to assess physical fitness in a representative sample of Spanish adolescents (n=2859; 1357 boys and 1502 girls) taking part in the AVENA (Alimentación y Valoración del Estado Nutricional de los Adolescentes) study. Standard parameters for the physical condition of Spanish adolescents are reported in this study. The 5th percentile for maximum aerobic capacity (Course Navette test) ranged from 2.0-3.3 palier in boys and from 1.4-1.9 palier in girls. The findings indicate that, on the basis of aerobic fitness, approximately 20% of Spanish adolescents have an increased risk of future cardiovascular disease. This subgroup also performed poorly in all other tests of physical fitness used. The results reported in this study enable the level of physical fitness in adolescents to be interpreted as an indicator of future cardiovascular health. They also indicate that the physical fitness of Spanish adolescents must be improved to help protect against cardiovascular disease in adulthood.

  13. The Materials Used and the Pupils Involved in Environmental Studies and Environmental Science at GCE 'O' and 'A' Level.

    ERIC Educational Resources Information Center

    Gayford, Christopher

    1984-01-01

    Discusses types of students and materials and resources used in O- and A-level environmental studies and environmental science courses. Indicates that these subjects are very susceptable to the attitudes of teachers (as shown by their willingness to produce satisfactory materials) and by the motivation of students. (JN)

  14. Longevity-relevant regulation of autophagy at the level of the acetylproteome.

    PubMed

    Mariño, Guillermo; Morselli, Eugenia; Bennetzen, Martin V; Eisenberg, Tobias; Megalou, Evgenia; Schroeder, Sabrina; Cabrera, Sandra; Bénit, Paule; Rustin, Pierre; Criollo, Alfredo; Kepp, Oliver; Galluzzi, Lorenzo; Shen, Shensi; Malik, Shoaib A; Maiuri, Maria Chiara; Horio, Yoshiyuki; López-Otín, Carlos; Andersen, Jens S; Tavernarakis, Nektarios; Madeo, Frank; Kroemer, Guido

    2011-06-01

    The acetylase inhibitor, spermidine and the deacetylase activator, resveratrol, both induce autophagy and prolong life span of the model organism Caenorhabditis elegans in an autophagydependent fashion. Based on these premises, we investigated the differences and similarities in spermidine and resveratrol-induced autophagy. The deacetylase sirtuin 1 (SIRT1) and its orthologs are required for the autophagy induction by resveratrol but dispensable for autophagy stimulation by spermidine in human cells, Saccharomyces cerevisiae and C. elegans. SIRT1 is also dispensable for life-span extension by spermidine. Mass spectrometry analysis of the human acetylproteome revealed that resveratrol and/or spermidine induce changes in the acetylation of 560 peptides corresponding to 375 different proteins. Among these, 170 proteins are part of the recently elucidated human autophagy protein network. Importantly, spermidine and resveratrol frequently affect the acetylation pattern in a similar fashion. In the cytoplasm, spermidine and resveratrol induce convergent protein de-acetylation more frequently than convergent acetylation, while in the nucleus, acetylation is dominantly triggered by both agents. We surmise that subtle and concerted alterations in the acetylproteome regulate autophagy at multiple levels.

  15. Toxic effects of pesticide mixtures at a molecular level: their relevance to human health.

    PubMed

    Hernández, Antonio F; Parrón, Tesifón; Tsatsakis, Aristidis M; Requena, Mar; Alarcón, Raquel; López-Guarnido, Olga

    2013-05-10

    Pesticides almost always occur in mixtures with other ones. The toxicological effects of low-dose pesticide mixtures on the human health are largely unknown, although there are growing concerns about their safety. The combined toxicological effects of two or more components of a pesticide mixture can take one of three forms: independent, dose addition or interaction. Not all mixtures of pesticides with similar chemical structures produce additive effects; thus, if they act on multiple sites their mixtures may produce different toxic effects. The additive approach also fails when evaluating mixtures that involve a secondary chemical that changes the toxicokinetics of the pesticide as a result of its increased activation or decreased detoxification, which is followed by an enhanced or reduced toxicity, respectively. This review addresses a number of toxicological interactions of pesticide mixtures at a molecular level. Examples of such interactions include the postulated mechanisms for the potentiation of pyrethroid, carbaryl and triazine herbicides toxicity by organophosphates; how the toxicity of some organophosphates can be potentiated by other organophosphates or by previous exposure to organochlorines; the synergism between pyrethroid and carbamate compounds and the antagonism between triazine herbicides and prochloraz. Particular interactions are also addressed, such as those of pesticides acting as endocrine disruptors, the cumulative toxicity of organophosphates and organochlorines resulting in estrogenic effects and the promotion of organophosphate-induced delayed polyneuropathy.

  16. Relevance and clinical significance of serum resistin level in obese T2DM rhesus monkey models.

    PubMed

    Qi, S-D; He, Z-L; Chen, Y; Ma, J; Yu, W-H; Li, Y-Y; Yang, F-M; Wang, J-B; Chen, L-X; Zhao, Y; Lu, S-Y

    2015-09-01

    Resistin is a type of hormone-like adipocytokines, which is secreted specifically by adipocytes. It may be a key factor in the development of type 2 diabetes mellitus (T2DM) from obesity- associated insulin resistance due to results that show that it has a close relationship with insulin resistance in rodents. We utilized the rhesus monkeys as study objects to preliminarily test the association with glucose metabolism and to conduct a correlation analysis for clinical parameters and serum resistin levels in obese rhesus monkey models of T2DM. The results suggested that resistin was significantly increased in T2DM monkeys (P <0.01), and that resistin had a positive correlation respectively with total cholesterol (TC), low-density lipoprotein (LDL-C), fasting plasma glucose (FPG), fasting insulin (FPI) and glycated hemoglobin (HbA1c), Insulin resistance index (HOA-IR), but a negative correlation with islet β-cell function (HOMA-β). In the course of glucose metabolism, reverse release change of resistin and insulin in T2DM monkeys occurred, but the phenomenon that was not observed in the control group, these findings indicated that resistin negatively regulated and interfered with carbohydrate metabolism in T2DM monkey models. The character of the releasing change of resistin might be a unique process in T2DM. Therefore, all of the results could provide references for clinical diagnostic criteria for human cases of T2DM, and could have clinical significance for obese T2DM diagnosis and degree of insulin resistance. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Characterization and environmental relevance of oil water preparations of fresh and weathered MC-252 Macondo oils used in toxicology testing.

    PubMed

    Sandoval, Kathia; Ding, Yan; Gardinali, Piero

    2017-01-15

    results from high-energy preparations needs to be further evaluated. When the TPAHs concentrations of all preparations at all loadings were compared with the publicly available water-column data for samples analyzed during and after the DWH incident response they all ranked above the vast majority of the 10,828 samples reported. Until a better characterization of all the available DWH water column individual-component chemistry data is produced the question of environmental relevance and the pursuit of toxicological studies under more realistic conditions continues to be a significant challenge that should be further explored.

  18. New techniques of low level environmental radiation monitoring at JLab

    SciTech Connect

    P. Degtiarenko, V. Popov

    2010-07-01

    We present the first long-term environmental radiation monitoring results obtained using the technique of pulse mode readout for the industry-standard Reuter-Stokes RSS-1013 argon-filled high pressure ionization chambers (HPIC). With novel designs for the front-end electronics readout and customized signal processing algorithms, we are capable of detecting individual events of gas ionization in the HPIC, caused by interactions of gammas and charged particles in the gas. The technique provides enough spectroscopic information to distinguish between several different types of environmental and man-made radiation. The technique also achieves a high degree of sensitivity and stability of the data, allowing long-term environmental radiation monitoring with unprecedented precision.

  19. Immunomodulation of Mytilus hemocytes by individual estrogenic chemicals and environmentally relevant mixtures of estrogens: in vitro and in vivo studies.

    PubMed

    Canesi, Laura; Lorusso, Lucia Cecilia; Ciacci, Caterina; Betti, Michele; Rocchi, Marco; Pojana, Giulio; Marcomini, Antonio

    2007-02-15

    Endocrine disrupting compounds (EDCs) are almost ubiquitous in the aquatic environment. In the marine bivalve Mytilus the natural estrogen 17beta-estradiol (E2) and different EDCs have been recently demonstrated to affect the function of the immune cells, the hemocytes. The effects were Tamoxifen-sensitive and were mediated by rapid modulation of kinase-mediated transduction pathways. In this work we compared the in vitro effects of individual estrogenic chemicals (E2, EE: 17alpha-ethynyl estradiol; MES: mestranol; NP: nonylphenol; NP1EC: nonylphenol monoethoxylate carboxylate; BPA: bisphenol A; BP: benzophenone) on hemocyte parameters: lysosomal membrane stability (LMS), phagocytosis, lysozyme release. LMS was the most sensitive effect parameter, showing a decreasing trend at increasing concentrations of estrogens. EC50 values obtained from LMS data were utilized to calculate the estradiol equivalency factor (EEF) for each compound; these EEFs allowed for an estimation of the estrogenic potential of a synthetic mixture with a composition very similar to that previously found in waters of the Venice lagoon. Concentrated mixtures significantly affected hemocyte parameters in vitro and the effects were prevented by Tamoxifen. Significant effects of the mixture were also observed in vivo, at longer exposure times and at concentrations comparable with environmental exposure levels. The results indicate that Mytilus immune parameters can be suitably utilized to evaluate the estrogenic potential of environmental samples.

  20. 24 CFR 35.1225 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intervention blood lead level. 35.1225 Section 35.1225 Housing and Urban Development Office of the Secretary... STRUCTURES Tenant-Based Rental Assistance § 35.1225 Child with an environmental intervention blood lead level... as having an environmental intervention blood lead level, the designated party shall complete a...

  1. 24 CFR 35.1225 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intervention blood lead level. 35.1225 Section 35.1225 Housing and Urban Development Office of the Secretary... STRUCTURES Tenant-Based Rental Assistance § 35.1225 Child with an environmental intervention blood lead level... as having an environmental intervention blood lead level, the designated party shall complete a...

  2. 24 CFR 35.730 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intervention blood lead level. 35.730 Section 35.730 Housing and Urban Development Office of the Secretary... STRUCTURES Project-Based Assistance § 35.730 Child with an environmental intervention blood lead level. (a... subpart applies has been identified as having an environmental intervention blood lead level, the...

  3. 24 CFR 35.730 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intervention blood lead level. 35.730 Section 35.730 Housing and Urban Development Office of the Secretary... STRUCTURES Project-Based Assistance § 35.730 Child with an environmental intervention blood lead level. (a... subpart applies has been identified as having an environmental intervention blood lead level, the...

  4. 24 CFR 35.1225 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intervention blood lead level. 35.1225 Section 35.1225 Housing and Urban Development Office of the Secretary... STRUCTURES Tenant-Based Rental Assistance § 35.1225 Child with an environmental intervention blood lead level... as having an environmental intervention blood lead level, the designated party shall complete a...

  5. 24 CFR 35.325 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intervention blood lead level. 35.325 Section 35.325 Housing and Urban Development Office of the Secretary... environmental intervention blood lead level. If a child less than 6 years of age living in a federally assisted dwelling unit has an environmental intervention blood lead level, the owner shall immediately conduct...

  6. 24 CFR 35.325 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intervention blood lead level. 35.325 Section 35.325 Housing and Urban Development Office of the Secretary... environmental intervention blood lead level. If a child less than 6 years of age living in a federally assisted dwelling unit has an environmental intervention blood lead level, the owner shall immediately conduct...

  7. 24 CFR 35.1130 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intervention blood lead level. 35.1130 Section 35.1130 Housing and Urban Development Office of the Secretary... STRUCTURES Public Housing Programs § 35.1130 Child with an environmental intervention blood lead level. (a... been identified as having an environmental intervention blood lead level, the PHA shall complete a...

  8. 24 CFR 35.325 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intervention blood lead level. 35.325 Section 35.325 Housing and Urban Development Office of the Secretary... environmental intervention blood lead level. If a child less than 6 years of age living in a federally assisted dwelling unit has an environmental intervention blood lead level, the owner shall immediately conduct...

  9. 24 CFR 35.1130 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intervention blood lead level. 35.1130 Section 35.1130 Housing and Urban Development Office of the Secretary... STRUCTURES Public Housing Programs § 35.1130 Child with an environmental intervention blood lead level. (a... been identified as having an environmental intervention blood lead level, the PHA shall complete a...

  10. 24 CFR 35.1130 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intervention blood lead level. 35.1130 Section 35.1130 Housing and Urban Development Office of the Secretary... STRUCTURES Public Housing Programs § 35.1130 Child with an environmental intervention blood lead level. (a... been identified as having an environmental intervention blood lead level, the PHA shall complete a...

  11. 24 CFR 35.730 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intervention blood lead level. 35.730 Section 35.730 Housing and Urban Development Office of the Secretary... STRUCTURES Project-Based Assistance § 35.730 Child with an environmental intervention blood lead level. (a... subpart applies has been identified as having an environmental intervention blood lead level, the...

  12. 24 CFR 35.325 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intervention blood lead level. 35.325 Section 35.325 Housing and Urban Development Office of the Secretary... environmental intervention blood lead level. If a child less than 6 years of age living in a federally assisted dwelling unit has an environmental intervention blood lead level, the owner shall immediately conduct...

  13. 24 CFR 35.1225 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intervention blood lead level. 35.1225 Section 35.1225 Housing and Urban Development Office of the Secretary... STRUCTURES Tenant-Based Rental Assistance § 35.1225 Child with an environmental intervention blood lead level... as having an environmental intervention blood lead level, the designated party shall complete a...

  14. 24 CFR 35.1130 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intervention blood lead level. 35.1130 Section 35.1130 Housing and Urban Development Office of the Secretary... STRUCTURES Public Housing Programs § 35.1130 Child with an environmental intervention blood lead level. (a... been identified as having an environmental intervention blood lead level, the PHA shall complete a...

  15. 24 CFR 35.730 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intervention blood lead level. 35.730 Section 35.730 Housing and Urban Development Office of the Secretary... STRUCTURES Project-Based Assistance § 35.730 Child with an environmental intervention blood lead level. (a... subpart applies has been identified as having an environmental intervention blood lead level, the...

  16. 24 CFR 35.325 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intervention blood lead level. 35.325 Section 35.325 Housing and Urban Development Office of the Secretary... environmental intervention blood lead level. If a child less than 6 years of age living in a federally assisted dwelling unit has an environmental intervention blood lead level, the owner shall immediately conduct...

  17. 24 CFR 35.1225 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intervention blood lead level. 35.1225 Section 35.1225 Housing and Urban Development Office of the Secretary... STRUCTURES Tenant-Based Rental Assistance § 35.1225 Child with an environmental intervention blood lead level... as having an environmental intervention blood lead level, the designated party shall complete a...

  18. 24 CFR 35.730 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intervention blood lead level. 35.730 Section 35.730 Housing and Urban Development Office of the Secretary... STRUCTURES Project-Based Assistance § 35.730 Child with an environmental intervention blood lead level. (a... subpart applies has been identified as having an environmental intervention blood lead level, the...

  19. 24 CFR 35.1130 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intervention blood lead level. 35.1130 Section 35.1130 Housing and Urban Development Office of the Secretary... STRUCTURES Public Housing Programs § 35.1130 Child with an environmental intervention blood lead level. (a... been identified as having an environmental intervention blood lead level, the PHA shall complete a...

  20. Gene expression profiling to identify the toxicities and potentially relevant human disease outcomes associated with environmental heavy metal exposure.

    PubMed

    Korashy, Hesham M; Attafi, Ibraheem M; Famulski, Konrad S; Bakheet, Saleh A; Hafez, Mohammed M; Alsaad, Abdulaziz M S; Al-Ghadeer, Abdul Rahman M

    2017-02-01

    Heavy metals are the most commonly encountered toxic substances that increase susceptibility to various diseases after prolonged exposure. We have previously shown that healthy volunteers living near a mining area had significant contamination with heavy metals associated with significant changes in the expression of some detoxifying genes, xenobiotic metabolizing enzymes, and DNA repair genes. However, alterations of most of the molecular target genes associated with diseases are still unknown. Thus, the aims of this study were to (a) evaluate the gene expression profile and (b) identify the toxicities and potentially relevant human disease outcomes associated with long-term human exposure to environmental heavy metals in mining area using microarray analysis. For this purpose, 40 healthy male volunteers who were residents of a heavy metal-polluted area (Mahd Al-Dhahab city, Saudi Arabia) and 20 healthy male volunteers who were residents of a non-heavy metal-polluted area were included in the study. Total RNA was isolated from whole blood using PAXgene Blood RNA tubes and then reversed transcribed and hybridized to the gene array using the Affymetrix U219 GeneChip. Microarray analysis showed about 2129 genes were identified and differentially altered, among which a shared set of 425 genes was differentially expressed in the heavy metal-exposed groups. Ingenuity pathway analysis revealed that the most altered gene-regulated diseases in heavy metal-exposed groups included hematological and developmental disorders and mostly renal and urological diseases. Quantitative real-time polymerase chain reaction closely matched the microarray data for some genes tested. Importantly, changes in gene-related diseases were attributed to alterations in the genes encoded for protein synthesis. Renal and urological diseases were the diseases that were most frequently associated with the heavy metal-exposed group. Therefore, there is a need for further studies to validate these

  1. Assessing the effects of the antidepressant venlafaxine to fathead minnows exposed to environmentally relevant concentrations over a full life cycle.

    PubMed

    Parrott, Joanne L; Metcalfe, Chris D

    2017-10-01

    Venlafaxine is an antidepressant drug that has been detected in municipal wastewater effluents at low μg/L concentrations. To assess the potential of this compound to affect the survival, development and reproductive capacity of fish, we exposed fathead minnow (Pimephales promelas) over a full lifecycle in a flow-through system to nominal venlafaxine concentrations of 0.88, 8.8, and 88 μg/L. Mean measured venlafaxine concentrations in these treatments were 1.0, 9.3 and 75 μg/L. During the 167-168 d exposure, no significant changes were observed in survival, or the weights and lengths of fathead minnows. At maturity, there were no significant differences relative to controls in condition factor, liver-somatic index, or secondary sex characteristics in the venlafaxine exposed male or female fish. Fathead minnows from the highest venlafaxine treatment (i.e. 88 μg/L) produced 46% more eggs per female than control fish (p = 0.031). Egg quality, % fertilization, % hatching, and % deformities in F1 fry were unaffected by exposure of the parent fish to venlafaxine at any of the test concentrations. Venlafaxine exposure at environmentally relevant concentrations (i.e. 0.88 and 8.8 μg/L) caused no adverse effects in fathead minnows. This study is the first to assess the potential for effects in fish exposed to the antidepressant venlafaxine over a full lifecycle. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  2. Effects of the boscalid fungicide Filan® on the marine amphipod Allorchestes compressa at environmentally relevant concentrations.

    PubMed

    Vu, Hung T; Keough, Michael J; Long, Sara M; Pettigrove, Vincent J

    2016-05-01

    Fungicides are widely used in agriculture to control fungal diseases. After application, fungicides can be transported offsite to surface and groundwater and ultimately enter estuarine and marine environments. The presence of fungicides in the marine environment may pose risks to marine organisms, but little is known about fungicide effects on these organisms, especially invertebrates. The present study investigated the effects of the commonly used boscalid fungicide Filan® on life history traits, feeding rate, and energy reserves (lipid, glycogen, and protein content) of the marine amphipod Allorchestes compressa over 6 wk under laboratory conditions. Amphipods were exposed to 3 concentrations of Filan (1 μg, 10 μg, and 40 μg active ingredient [a.i.]/L), with 5 replicates per treatment. Lipid content and reproduction were the most sensitive measures of effect, with lipid content reduced by 53.8% at the highest concentration. Survival, growth, and other energy reserves of amphipods were also negatively affected by Filan, and the effects were concentration dependent. Antennal deformities were incidentally observed on the amphipods at a concentration of 40 μg a.i./L. The results of the present study indicate comprehensive effects of the boscalid fungicide Filan on A. compressa at environmentally relevant concentrations. The decline or absence of A. compressa in marine ecosystems could impair the ecosystem function because of their important role in trophic transfer and nutrient recycling. The authors' results suggest that even though the use of fungicides is often regarded as posing only a minor risk to aquatic organisms, the assessment of their long-term effects is critical. © 2015 SETAC.

  3. First evidences of PAMAM dendrimer internalization in microorganisms of environmental relevance: A linkage with toxicity and oxidative stress.

    PubMed

    Gonzalo, Soledad; Rodea-Palomares, Ismael; Leganés, Francisco; García-Calvo, Eloy; Rosal, Roberto; Fernández-Piñas, Francisca

    2015-01-01

    This article reports novel results on the toxic mechanisms of action of amine- and hydroxyl-terminated poly(amidoamine) (PAMAM) dendrimers toward microorganisms of environmental relevance, namely a cyanobacterium of the genus Anabaena and the green alga Chlamydomonas reinhardtii. We used PAMAM ethylenediamine core dendrimers from generations G2 to G4, which displayed a positive charge, measured as ζ-potential, in culture media. All amine-terminated and most remarkably the G4 hydroxyl-terminated dendrimer inhibited the growth of both microorganisms. The effect on the growth of the green alga was significantly higher than that on the cyanobacterium. With concentrations expressed in terms of molarity, there was a clear relationship between dendrimer generation and toxicity, with higher toxicity for higher generation. Hormesis was observed for hydroxyl-terminated dendrimers at low concentrations. The cationic dendrimers and G4-OH significantly increased the formation of reactive oxygen species (ROS) in both organisms. ROS formation was not related with the chloroplast or photosynthetic membranes and photosystem II photochemistry was unaffected. Cell damage resulted in cytoplasm disorganization and cell deformities and was associated to an increase in ROS formation and lipid peroxidation in mitochondria in the green alga; cell wall and membrane disruption with apparent loss of cytoplasmic contents was found in the cyanobacterium. It was determined for the first time that cationic PAMAM dendrimers were quickly and largely internalized by both organisms. These results warn against the generalization of the use of dendrimers, which may pose significant risk for the environment and particularly for primary producers which are determinant for the health of natural ecosystems.

  4. Single and combined toxicity of pharmaceuticals at environmentally relevant concentrations in Daphnia magna--a multigenerational study.

    PubMed

    Dietrich, Sabine; Ploessl, Florian; Bracher, Franz; Laforsch, Christian

    2010-03-01

    Pharmaceuticals are continuously discharged into the environment, resulting in the chronic exposure of aquatic organisms to these compounds. In this multigenerational study, we examined the influence of four pharmaceuticals (carbamazepine (CBZ), diclofenac (DIC), 17alpha-ethinylestradiol (EE2) and metoprolol (MET)) as single substances and as a drug mixture at environmentally relevant concentrations on life-history and morphological parameters over six generations of the cladoceran Daphnia magna. Detectable effects of the used pharmaceuticals occured in the first observed generation, followed by an acclimation period and a recurrence of drug effects in later generations: daphnids exposed to MET were affected by the pharmaceutical, resulting in a decreased body length at first reproduction in the generations F0, F3 and F4 and in a reduced number of offspring in the generations F0 and F4. Similar effects were observed in daphnids exposed to EE2. DIC delayed age at first reproduction in the F0 and F2 generations and increased the body length of neonates in the generations F1 and F5. Daphnids exposed to CBZ showed a delay in the age at first reproduction for the F0 generation only. The drug mixture reduced the age at first reproduction of daphnids in the F0 and F2 generation and increased the body length at first reproduction in the generations F0 and F3. Neither the single drugs nor the pharmaceutical mixture influenced the successive generations of D. magna in a steady way. Thus, multigenerational studies are necessary to prevent insufficient assessments on the impact of pharmaceuticals in aquatic ecosystems.

  5. Preservice Teachers' Perception Levels Concerning Consumer Environmental Consciousness

    ERIC Educational Resources Information Center

    Dikmenli, Yurdal

    2017-01-01

    People who strive to prevent harm to the environment while utilizing it and to maintain a livable environment is related to educational and cultural values. If we want the next generation to live in an environment as undisturbed as we live in now, environmentally friendly products should be consumed and waste should be prevented. Thus, raising an…

  6. Teacher Candidates' Attitudes, Knowledge Levels and Sensitivities towards Environmental Problems

    ERIC Educational Resources Information Center

    Akman, Ozkan

    2017-01-01

    "A people without children would face a hopeless future; a country without trees is almost as helpless" (Theodore Roosevelt). Humans both have been affected by environmental events and have affected their environments by a variety of activities since man has been on earth. However, because of the lack of population for a long time and…

  7. Chronic exposure by ingestion of environmentally relevant doses of (226)Ra leads to transient growth perturbations in fathead minnow (Pimephales promelas, Rafinesque, 1820).

    PubMed

    Mothersill, Carmel; Smith, Richard; Lariviere, Dominic; Seymour, Colin

    2013-11-01

    To assess the impact of environmentally relevant levels of ingested (226)Ra on a common freshwater fish species. Fathead minnow (Pimephales promelas, Rafinesque) were obtained at the first feeding stage and established on a commercial fish food diet containing (226)Ra in the activity range 10 mBq/g(-1), -10,000 mBq/g(-1). They remained on this diet for 24 months and were sampled invasively at 1,6,18 and 24 months to assess growth, biochemical indices and accumulated dose and non-invasively also at 12 and 15 months to assess growth. Fish fed 10 and 100 mBq/g(-1) diet showed a small transitory deregulation of growth at 6 and 12 months. Fish fed higher activities showed less significant or insignificant effects. There was a trend at 18 months which was stronger at 24 months for the population distribution to change in all of the (226)Ra fed groups so that smaller fish were smaller and bigger fish were bigger than the controls. There were also significant differences in the ratios of protein:DNA at 24 months which were seen as a trend but were not significant at earlier time points. Fish fed a radium diet for 2 years show a small and transitory growth dysregulation at 6 and 12 months. The effects predominate at the lower activities suggesting hormetic or homeostatic adjustments. There was no effect on growth of exposure to the high activities (226)Ra. This suggests that radium does not have a serious impact on the ecology of the system and the level of radium that would be transferred to humans is very low. The results may be important in the assessment of long-term environmental impacts of (226)Ra exposure.

  8. Exposure of Female Rats to an Environmentally Relevant Mixture of Brominated Flame Retardants Targets the Ovary, Affecting Folliculogenesis and Steroidogenesis1

    PubMed Central

    Lefèvre, Pavine L.C.; Berger, Robert G.; Ernest, Sheila R.; Gaertner, Dean W.; Rawn, Dorothea F.K.; Wade, Michael G.; Robaire, Bernard; Hales, Barbara F.

    2015-01-01

    Brominated flame retardants (BFRs) are incorporated into various consumer products to prevent flame propagation. These compounds leach into the domestic environment, resulting in chronic exposure and contamination. Pregnancy failure is associated with high levels of BFRs in human follicular fluid, raising serious questions regarding their impact on female reproductive health. The goal of this study is to elucidate the effects of an environmentally relevant BFR mixture on female rat ovarian functions (i.e., folliculogenesis and steroidogenesis). A BFR dietary mixture formulated to mimic the relative BFR congener levels in North American house dust was administered to adult female Sprague-Dawley rats from 2 to 3 wk before mating until Gestational Day 20; these diets were designed to deliver nominal doses of 0, 0.06, 20, or 60 mg/kg/day of the BFR mixture. Exposure to BFRs triggered an approximately 50% increase in the numbers of preantral and antral follicles and an enlargement of the antral follicles in the ovaries of the dams. A significant reduction in the expression of catalase, an antioxidant enzyme, and downregulation of the expression of insulin-like factor 3 (Insl3) and 17alpha-hydroxylase (Cyp17a1) were observed in the ovary. In addition, BFR exposure affected steroidogenesis; we observed a significant decrease in circulating 17-hydroxypregnenolone and an increase in testosterone concentrations in BFR-exposed dams. Thus, BFRs target ovarian function in the rat, adversely affecting both folliculogenesis and steroidogenesis. PMID:26607716

  9. Studies of Corrosion Resistant Materials Being Considered for High-Level Nuclear Waste Containment in Yucca Mountain Relevant Environments

    SciTech Connect

    McCright, R.D.; Ilevbare, G.; Estill, J.; Rebak, R.

    2001-12-09

    Containment of spent nuclear fuel and vitrified forms of high level nuclear waste require use of materials that are highly corrosion resistant to all of the anticipated environmental scenarios that can occur in a geological repository. Ni-Cr-Mo Alloy 22 (UNS N60622) is proposed for the corrosion resistant outer barrier of a two-layer waste package container at the potential repository site at Yucca Mountain. A range of water compositions that may contact the outer barrier is under consideration, and a testing program is underway to characterize the forms of corrosion and to quantify the corrosion rates. Results from the testing support models for long term prediction of the performance of the container. Results obtained to date indicate a very low general corrosion rate for Alloy 22 and very high resistance to all forms of localized and environmentally assisted cracking in environments tested to date.

  10. An Explorative Study on Environmental Literacy among the Secondary Level Students in Bangladesh

    ERIC Educational Resources Information Center

    Sarkar, Md. Mahbub Alam; Ara, Quazi Afroz Jahan; Raihan, Jahir; Ozaki, Koji

    2008-01-01

    This study was intended to explore the environmental literacy among the secondary level students of Bangladesh. Specifically, it was designed to: i) determine environmental knowledge of the secondary students, ii) explore their environmental attitude, iii) find out their environment related practices, and iv) explore school's environment-friendly…

  11. Cardiovascular actions of cadmium at environmental exposure levels

    SciTech Connect

    Kopp, S.J.; Glonek, T.; Perry, H.M. Jr.; Erlanger, M.; Perry, E.F.

    1982-08-27

    A low intake of dietary cadmium induces specific dose-dependent functional and biochemical changes in the cardiovascular tissues of rats. Maximum changes occur when the cadmium intake is 10 to 20 micrograms per kilogram of body weight per day. The changes reflect the accumulation of critical concentrations of cadmium in the cardiovascular tissues. The biologic activity of cadmium is demonstrated for intakes that approach those of the average American adult exposed to the usual environmental concentrations of the element but not to industrial concentrations. The sensitivity of the cardiovascular system to low doses of cadmium could not be anticipated by extrapolation from data on exposure to high concentrations of cadmium. The data support the hypothesis that ingested or inhaled environmental cadmium may contribute to essential hypertension in humans.

  12. Environmental levels of the antidepressant venlafaxine impact the metabolic capacity of rainbow trout.

    PubMed

    Best, Carol; Melnyk-Lamont, Nataliya; Gesto, Manuel; Vijayan, Mathilakath M

    2014-10-01

    The antidepressant venlafaxine is detected at parts per billion levels in tertiary-treated municipal wastewater effluent. However, the impact of this serotonin-norepinephrine reuptake inhibitor (SNRI) on non-target aquatic animals is poorly understood. We tested the hypothesis that environmentally relevant levels of venlafaxine disrupt the highly conserved cortisol and glucose response to stress in rainbow trout (Oncorhynchus mykiss). Juvenile trout were exposed to venlafaxine (0, 0.2 and 1.0 μg/L) in a static system with daily renewal for seven days. The fish were then subjected to an acute handling disturbance and sampled either prior to (0 h) or 1, 4 and 24h after stressor exposure. Venlafaxine exposure did not affect the handling disturbance-mediated transient elevation in plasma cortisol levels or target tissue glucocorticoid receptor expression. The drug exposure disrupted the interrenal steroidogenic capacity, including altered handling stressor-mediated changes in mRNA abundances of steroidogenic acute regulatory protein and cytochrome P450 side chain cleavage. The handling stressor-induced transient elevations in plasma glucose levels were significantly reduced in the venlafaxine-exposed fish. This was not accompanied by changes in liver glycogen content, glucose transporter 2 mRNA abundance or the glycolytic capacity, whereas the capacity for gluconeogenesis and amino acid catabolism were enhanced. Venlafaxine also brought about changes in the gill of trout, including enhanced lactate dehydrogenase activity and Na(+)-K(+) ATPase protein expression, while the Na(+)-K(+) ATPase enzyme activity was reduced. Collectively, our results demonstrate that venlafaxine at levels detected in the aquatic environment impacts tissue metabolic capacities and may compromise the adaptive responses to an acute stressor in rainbow trout. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Evaluation of diagnostic relevance of mRNA levels in peripheral blood: predictive value for mortality in hemodialysis patients.

    PubMed

    Füth, Reiner; Herder, Christian; Förster, Stefan; Müller-Scholze, Sylvia; Kruse, Niels; Rieckmann, Peter; Heinig, Antonia; Koenig, Wolfgang; Scherbaum, Werner A; Kolb, Hubert; Martin, Stephan

    2004-09-21

    In clinical practice, diagnosis and risk prediction are usually based on the analysis of serum or plasma proteins whereas gene expression analysis is not used on a routine basis. In order to compare the diagnostic and predictive relevance of serum protein and peripheral blood mRNA levels, we determined cytokine levels of end-stage renal failure patients undergoing hemodialysis. These patients face a high mortality mainly due to acceleration of atherosclerosis and subsequent severe vascular events. mRNA expression of the pro-inflammatory cytokine TNF alpha was significantly elevated in hemodialysis patients and further increased after 2 h of dialysis treatment. In contrast, gene expression of the anti-inflammatory cytokine TGF beta was significantly decreased. Patients who died during the observation period of 36 months had significantly increased mRNA levels of TNF alpha and decreased TGF beta mRNA expression at baseline. Survival analysis indicated that increased TNF alpha mRNA levels (P < 0.02) and TNF alpha/TGF beta mRNA ratios (P < 0.001) predict mortality. The corresponding cytokines in serum showed some association with disease, but serum concentrations neither changed during hemodialysis nor predicted mortality. This study shows that gene expression patterns of circulating leukocytes may present an important new diagnostic tool to predict clinical outcome in patients with inflammatory vascular diseases.

  14. Effects of chronic exposure to an environmentally relevant mixture of brominated flame retardants on the reproductive and thyroid system in adult male rats.

    PubMed

    Ernest, Sheila R; Wade, Michael G; Lalancette, Claudia; Ma, Yi-Qian; Berger, Robert G; Robaire, Bernard; Hales, Barbara F

    2012-06-01

    Brominated flame retardants (BFRs) are incorporated into a wide variety of consumer products, are readily released into home and work environments, and are present in house dust. Studies using animal models have revealed that exposure to polybrominated diphenyl ethers (PBDEs) may impair adult male reproductive function and thyroid hormone physiology. Such studies have generally characterized the outcome of acute or chronic exposure to a single BFR technical mixture or congener but not the impact of environmentally relevant BFR mixtures. We tested whether exposure to the BFRs found in house dust would have an adverse impact on the adult male rat reproductive system and thyroid function. Adult male Sprague Dawley rats were exposed to a complex BFR mixture composed of three commercial brominated diphenyl ethers (52.1% DE-71, 0.4% DE-79, and 44.2% decaBDE-209) and hexabromocyclododecane (3.3%), formulated to mimic the relative congener levels in house dust. BFRs were delivered in the diet at target doses of 0, 0.02, 0.2, 2, or 20 mg/kg/day for 70 days. Compared with controls, males exposed to the highest dose of BFRs displayed a significant increase in the weights of the kidneys and liver, which was accompanied by induction of CYP1A and CYP2B P450 hepatic drug-metabolizing enzymes. BFR exposure did not affect reproductive organ weights, serum testosterone levels, testicular function, or sperm DNA integrity. The highest dose caused thyroid toxicity as indicated by decreased serum thyroxine (T4) and hypertrophy of the thyroid gland epithelium. At lower doses, the thickness of the thyroid gland epithelium was reduced, but no changes in hormone levels (T4 and thyroid-stimulating hormone) were observed. Thus, exposure to BFRs affected liver and thyroid physiology but not male reproductive parameters.

  15. Formation of environmentally relevant brominated dioxins from 2,4,6,-tribromophenol via bromoperoxidase-catalyzed dimerization.

    PubMed

    Arnoldsson, Kristina; Andersson, Patrik L; Haglund, Peter

    2012-07-03

    Polybrominated dibenzo-p-dioxins (PBDD) are emerging environmental pollutants with structural similarities to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. The geographical and temporal variations of PBDD in biota samples from the Baltic Sea do not display features that are normally related to anthropogenic sources such as incineration, and therefore the natural formation of PBDDs has been suggested. This study of the bromoperoxidase mediated oxidative coupling of 2,4,6-tribromophenol (an abundant substance that is naturally formed in marine systems) identified the formation of ppb-level yields of 1,3,6,8-tetrabromodibenzo-p-dioxin (1,3,6,8-TeBDD) through direct condensation. Additional TeBDDs (1,3,7,9-TeBDD, 1,2,4,7-TeBDD, and/or 1,2,4,8-TeBDD) and tri-BDDs (1,3,7-TrBDD and 1,3,8-TrBDD) were frequently formed but at lower yields. The formation of these TeBDDs probably proceeds via bromine shifts or Smiles rearrangements, whereas the TrBDDs may result from subsequent debromination processes. Because all of the congeners formed by oxidative coupling and subsequent reactions are also found in Baltic Sea biota, the results support the theory that PBDDs are formed from natural precursors.

  16. Recent progress in the genetics and epigenetics of paraoxonase: why it is relevant to children’s environmental health

    PubMed Central

    Holland, N; Lizarraga, D; Huen, K

    2015-01-01

    Purpose of review Children are more susceptible to exposures in utero and during early childhood that may result in developmental problems and chronic diseases. Novel discoveries in the field of molecular epidemiology which can help explain susceptibility to exposures and disease will be demonstrated using the multifunctional enzyme paraoxonase (PON1) as an example. Recent findings The broad PON1 variability in humans, partly due to differences in genetics and age, can confer differential susceptibility because this enzyme can detoxify organophosphate pesticides and has antioxidant properties. Epigenetics plays a significant role in the mediation of the effects of environmental exposure on human health and is hypothesized to be a major contributing factor to the early-life origins of adult disease. Studies highlighted in this review demonstrate the relationship of PON1 polymorphisms with microRNA binding in addition to a link between DNA methylation in the transcriptional regulatory region with changes in PON1 enzyme levels. Other important methodologies such as ancestry informative markers and lactonase activity can enhance studies involving PON1. Summary This PON1 model demonstrates that integrating genetic and epigenetic factors as well as other novel methodologies can improve our understanding of important susceptibility factors linked to pediatric disease. PMID:25635583

  17. Recent progress in the genetics and epigenetics of paraoxonase: why it is relevant to children's environmental health.

    PubMed

    Holland, Nina; Lizarraga, Daneida; Huen, Karen

    2015-04-01

    Children are more susceptible to exposures in utero and during early childhood that may result in developmental problems and chronic diseases. Novel discoveries in the field of molecular epidemiology that can help explain susceptibility to exposures and disease will be demonstrated using the multifunctional enzyme paraoxonase 1 (PON1) as an example. The broad PON1 variability in humans, partly due to differences in genetics and age, can confer differential susceptibility because this enzyme can detoxify organophosphate pesticides and has antioxidant properties. Epigenetics plays a significant role in the mediation of the effects of environmental exposure on human health and is hypothesized to be a major contributing factor to the early-life origins of adult disease. Studies highlighted in this review demonstrate the relationship of PON1 polymorphisms with microRNA binding in addition to a link between DNA methylation in the transcriptional regulatory region with changes in PON1 enzyme levels. Other important methodologies such as ancestry informative markers and lactonase activity can enhance studies involving PON1. This PON1 model demonstrates that integrating genetic and epigenetic factors, as well as other novel methodologies, can improve our understanding of important susceptibility factors linked to pediatric disease.

  18. Behavioral response of manatees to variations in environmental sound levels

    USGS Publications Warehouse

    Miksis-Olds, J. L.; Wagner, T.

    2011-01-01

    Florida manatees (Trichechus manatus latirostris) inhabit coastal regions because they feed on the aquatic vegetation that grows in shallow waters, which are the same areas where human activities are greatest. Noise produced from anthropogenic and natural sources has the potential to affect these animals by eliciting responses ranging from mild behavioral changes to extreme aversion. Sound levels were calculated from recordings made throughout behavioral observation periods. An information theoretic approach was used to investigate the relationship between behavior patterns and sound level. Results indicated that elevated sound levels affect manatee activity and are a function of behavioral state. The proportion of time manatees spent feeding and milling changed in response to sound level. When ambient sound levels were highest, more time was spent in the directed, goal-oriented behavior of feeding, whereas less time was spent engaged in undirected behavior such as milling. This work illustrates how shifts in activity of individual manatees may be useful parameters for identifying impacts of noise on manatees and might inform population level effects. ?? 2010 by the Society for Marine Mammalogy.

  19. Genetic and environmental impacts on DNA methylation levels in twins.

    PubMed

    Yet, Idil; Tsai, Pei-Chien; Castillo-Fernandez, Juan E; Carnero-Montoro, Elena; Bell, Jordana T

    2016-01-01

    Epigenetics describes the study of cellular modifications that can modify the expression of genes without changing the DNA sequence. DNA methylation is one of the most stable and prevalent epigenetic mechanisms. Twin studies have been a valuable model for unraveling the genetic and epigenetic epidemiology of complex traits, and now offer a potential to dissect the factors that impact DNA methylation variability and its biomedical significance. The twin design specifically allows for the study of genetic, environmental and lifestyle factors, and their potential interactions, on epigenetic profiles. Furthermore, genetically identical twins offer a unique opportunity to assess nongenetic impacts on epigenetic profiles. Here, we summarize recent findings from twin studies of DNA methylation profiles across tissues, to define current knowledge regarding the genetic and nongenetic factors that influence epigenetic variation.

  20. Dental enamel as biomarker for environmental contaminants in relevant industrialized estuary areas in São Paulo, Brazil.

    PubMed

    de Oliveira, Vera Lucia Ferreira; Gerlach, Raquel Fernanda; Martins, Lourdes Conceição; de Souza Guerra, Carolina; Frazão, Paulo; Braga, Alfésio Luis Ferreira; Pereira, Luiz Alberto Amador

    2017-06-01

    Heavy metal contamination is a long-standing and very well-known public health problem, and its exposure can cause damage to several organs of human body, especially on the central nervous system of young children and teenagers. The aim of this article is to evaluate lead, cadmium, and manganese contamination in 125 children from 6 to 13 years old living in contaminated areas during the period from 2006 to 2009 (São Vicente, Cubatão Downtown, Bertioga and Cubatão Pilões/Água Fria). This estuary area is the most important example of environmental degradation by chemicals from industrial sources. This is a cross-sectional study through clinical examinations and dental enamel tests. All mothers from these children lived in the area since before the pregnancy. Lead, cadmium, and manganese levels (μg/g) were measured on dental enamel samples through graphite furnace atomic absorption spectrometry, searching for the occurrence of heavy metals. The mean lead concentrations were 139.48 μg/g in Cubatão Pilões/Água Fria, 170.45 μg/g in Cubatão Downtown, 213.52 μg/g in São Vicente, and 151.89 μg/g in Bertioga. The mean cadmium concentrations were 10.83 μg/g in Cubatão Pilões/Água Fria, 12.58 μg/g in Cubatão Downtown, 10.92 μg/g in São Vicente, and 14.57 μg/g in Bertioga. The mean manganese concentrations were 23.49 μg/g in Cubatão Pilões/Água Fria, 30.90 μg/g in Cubatão Downtown, 41.46 μg/g in São Vicente, and 42.00 μg/g in Bertioga. Dental surface enamel may be used as an efficient biomarker of past environmental exposure to lead, manganese, and cadmium which are associated to well-known sources of heavy metal contamination. The results suggest that the evaluated children were exposed to sources of lead, cadmium, and manganese since before their conceptions. Although Bertioga initially was chosen as a control area of this study, it was also was verified to have heavy metal contamination on examined children.

  1. Clinically Relevant Levels of 4-Aminopyridine Strengthen Physiological Responses in Intact Motor Circuits in Rats, Especially After Pyramidal Tract Injury.

    PubMed

    Sindhurakar, Anil; Mishra, Asht M; Gupta, Disha; Iaci, Jennifer F; Parry, Tom J; Carmel, Jason B

    2017-04-01

    4-Aminopyridine (4-AP) is a Food and Drug Administration-approved drug to improve motor function in people with multiple sclerosis. Preliminary results suggest the drug may act on intact neural circuits and not just on demyelinated ones. To determine if 4-AP at clinically relevant levels alters the excitability of intact motor circuits. In anesthetized rats, electrodes were placed over motor cortex and the dorsal cervical spinal cord for electrical stimulation, and electromyogram electrodes were inserted into biceps muscle to measure responses. The motor responses to brain and spinal cord stimulation were measured before and for 5 hours after 4-AP administration both in uninjured rats and rats with a cut lesion of the pyramidal tract. Blood was collected at the same time as electrophysiology to determine drug plasma concentration with a goal of 20 to 100 ng/mL. We first determined that a bolus infusion of 0.32 mg/kg 4-AP was optimal: it produced on average 61.5 ± 1.8 ng/mL over the 5 hours after infusion. This dose of 4-AP increased responses to spinal cord stimulation by 1.3-fold in uninjured rats and 3-fold in rats with pyramidal tract lesion. Responses to cortical stimulation also increased by 2-fold in uninjured rats and up to 4-fold in the injured. Clinically relevant levels of 4-AP strongly augment physiological responses in intact circuits, an effect that was more robust after partial injury, demonstrating its broad potential in treating central nervous system injuries.

  2. (CALIFORNIA) META-ANALYSIS OF THE LIFE STYLE FACTORS RELEVANT TO ENVIRONMENTAL HAZARDS FOR THE AGING POPULATION

    EPA Science Inventory

    The goal of this U.S. Environmental Protection Agency (EPA) Aging Initiative study is to characterize activity patterns, physiological changes, and environmental exposures for the aging population. Meta-analysis was performed on more than 2000 reviewed articles to evaluate the l...

  3. (CALIFORNIA) META-ANALYSIS OF THE LIFE STYLE FACTORS RELEVANT TO ENVIRONMENTAL HAZARDS FOR THE AGING POPULATION

    EPA Science Inventory

    The goal of this U.S. Environmental Protection Agency (EPA) Aging Initiative study is to characterize activity patterns, physiological changes, and environmental exposures for the aging population. Meta-analysis was performed on more than 2000 reviewed articles to evaluate the l...

  4. Environmentalism and low-level waste-the aftermath

    SciTech Connect

    Pastorelle, P.J.

    1995-05-01

    Radical Environmentalists, anxious to shut down nuclear power, are directing efforts against the disposal of low-level radioactive wastes (contaminated coveralls, tools, paper, plastic, glass, etc.). The rationals is that if nuclear power facilities cannot dispose of their waste streams, eventually they may have to stop operating. This article discusses the political and practical issues surrounding this approach.

  5. [Relevance between single nucleotide polymorphisms in nicotinic acetylcholine receptor genes and DNA damage levels in coke oven workers].

    PubMed

    Tu, Yi-xiao; Guo, Huan; Wu, Tang-chun

    2011-10-01

    To investigate the relevance between single nucleotide polymorphisms (SNPs) in CHRNA3-CHRNB4-CHRNA5 gene cluster and DNA damage levels in the coke oven workers. A total of 309 male subjects from a steel plant in Northern China were divided into high exposure group (154 workers) and low exposure group (155 workers) according to the concentrations of plasma benzoapyrene-r-7, t-8, t-9, c-10-tetrahydrotetrol-albumin (BPDE-Alb) adducts. DNA damage levels of peripheral blood lymphocytes were examined by comet assay. Allelic discrimination of SNPs in CHRNA3-CHRNB4-CHRNA5 gene cluster were detected using Matrix-assisted laser desorption/ionization mass spectrometry. The Olive tail moment (OTM) (1.23 ± 1.05) of peripheral blood lymphocytes in the high exposure group was significantly higher than that (0.80 ± 1.07) in the low exposure group (P < 0.01). In the high exposure group, OTM (1.64 ± 0.17) of subjects with rs667282CC genotype was significantly higher than those (0.95 ± 0.13 or 1.09 ± 0.11) of subjects with rs667282CT genotype or rs667282TT + CT genotype (P < 0.01); OTM (1.60 ± 0.17) of subjects with GG genotype at rs12910984 site was significantly higher than those (0.92 ± 0.13 or 1.07 ± 0.10) of subjects with AG genotype or AG + AA genotype (P < 0.01); OTM (1.35 ± 0.17 or 1.64 ± 0.17) of the TA/TA or CG/CG diplotype carriers was significantly higher than that (0.89 ± 0.13) of TA/CG diplotype carriers (P < 0.05). However, the relevance between genotypes of these SNPs and the DNA damage levels was not found in the low exposure group. The rs667282CC genotype and rs12910984GG genotype on CHRNA3-CHRNB4-CHRNA5 gene cluster are associated with increased DNA damage levels in the high PAHs exposure group.

  6. Delayed-Type Hypersensitivity to Metals of Environmental Burden in Patients with Takotsubo Syndrome – Is There a Clinical Relevance?

    PubMed Central

    Manousek, Jan; Stejskal, Vera; Kubena, Petr; Jarkovsky, Jiri; Nemec, Petr; Lokaj, Petr; Dostalova, Ludmila; Zadakova, Andrea; Pavlusova, Marie; Benesova, Klara; Kala, Petr; Miklik, Roman; Spinar, Jindrich; Parenica, Jiri

    2016-01-01

    Objective Takotsubo syndrome (TS) is a heart condition characterised by a sudden transient left ventricular dysfunction; its pathophysiology is probably associated with elevated levels of catecholamines but the exact mechanism is not known as yet. Literature and clinical experience suggest that TS affects persons with various comorbidities. This pilot work aims to evaluate the frequency of comorbidities with potential pathological immune reactivity, and to evaluate the potential association between TS and hypersensitivity to metals assessed by LTT-MELISA®. Methodology, Results A total of 24 patients (23 women, 1 man) with a history of TS attack and 27 healthy controls were evaluated. Hypersensitivity was evaluated by a lymphocyte transformation test (LTT-MELISA®); a questionnaire of environmental burden was used to select evaluated metals. A total of 19 patients (79%) had at least one condition that might potentially be associated with pathological immune reactivity (autoimmune thyroid disease, drug allergy, bronchial asthma, cancer, contact dermatitis, rheumatoid arthritis). Hypersensitivity to metals was identified significantly more frequently in TS patients than in healthy controls (positive reaction to at least one metal was identified in 95.8% of TS patients and in 59.3% of controls; p = 0.003); the difference was statistically significant for mercury (45.8% and 14.8%, respectively; p = 0.029). Conclusion Our work shows that conditions with pathological immune reactivity occur frequently in TS patients, and our data suggest a possible association between TS and hypersensitivity to metals (mercury in particular) evaluated by LTT-MELISA®. We also suggest that apart from the triggering stress factor, potential existence of other serious conditions should be considered when taking medical history of TS patients. PMID:27824862

  7. Effects of nanomolar copper on water plants--comparison of biochemical and biophysical mechanisms of deficiency and sublethal toxicity under environmentally relevant conditions.

    PubMed

    Thomas, George; Stärk, Hans-Joachim; Wellenreuther, Gerd; Dickinson, Bryan C; Küpper, Hendrik

    2013-09-15

    Toxicity and deficiency of essential trace elements like Cu are major global problems. Here, environmentally relevant sub-micromolar concentrations of Cu (supplied as CuSO4) and simulations of natural light- and temperature cycles were applied to the aquatic macrophyte Ceratophyllum demersum. Growth was optimal at 10nM Cu, while PSII activity (Fv/Fm) was maximal around 2 nM Cu. Damage to the PSII reaction centre was the first target of Cu toxicity, followed by disturbed regulation of heat dissipation (NPQ). Only after that, electron transport through PSII (ΦPSII) was inhibited, and finally chlorophylls decreased. Copper accumulation in the plants was stable until 10nM Cu in solution, but strongly increased at higher concentrations. The vein was the main storage site for Cu up to physiological concentrations (10nM). At toxic levels it was also sequestered to the epidermis and mesophyll until export from the vein became inhibited, accompanied by inhibition of Zn uptake. Copper deficiency led to a complete stop of growth at "0"nM Cu after 6 weeks. This was accompanied by high starch accumulation although electron flow through PSII (ΦPSII) decreased from 2 weeks, followed by decrease in pigments and increase of non photochemical quenching (NPQ). Release of Cu from the plants below 10nM Cu supply in the nutrient solution indicated lack of high-affinity Cu transporters, and on the tissue level copper deficiency led to a re-distribution of zinc. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Environmentally relevant concentration of arsenic trioxide and humic acid promoted tumor progression of human cervical cancer cells: In vivo and in vitro studies.

    PubMed

    Tsai, Min-Ling; Yen, Cheng-Chieh; Lu, Fung-Jou; Ting, Hung-Chih; Chang, Horng-Rong

    2016-09-01

    In a previous study, treatment at higher concentrations of arsenic trioxide or co-exposure to arsenic trioxide and humic acid was found to be inhibited cell growth of cervical cancer cells (SiHa cells) by reactive oxygen species generation. However, treatment at lower concentrations slightly increased cell viability. Here, we investigate the enhancement of progression effects of environmentally relevant concentration of humic acid and arsenic trioxide in SiHa cell lines in vitro and in vivo by measuring cell proliferation, migration, invasion, and the carcinogenesis-related protein (MMP-2, MMP-9, and VEGF-A) expressions. SiHa cells treated with low concentrations of humic acid and arsenic trioxide alone or in co-exposure significantly increased reactive oxygen species, glutathione levels, cell proliferation, scratch wound-healing activities, migration abilities, and MMP-2 expression as compared to the untreated control. In vivo the tumor volume of either single drug (humic acid or arsenic trioxide) or combined drug-treated group was significantly larger than that of the control for an additional 45 days after tumor cell injection on the back of NOD/SCID mice. Levels of MMP-2, MMP-9, and VEGF-A, also significantly increased compared to the control. Histopathologic effects of all tumor cells appeared round in cell shape with high mitosis, focal hyperkeratosis and epidermal hyperplasia in the skin, and some tumor growth in the muscle were observed. Our results may indicate that exposure to low concentrations of arsenic trioxide and humic acid is associated with the progression of cervical cancer. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1121-1132, 2016. © 2015 Wiley Periodicals, Inc.

  9. Toxicity of CeO₂ nanoparticles on a freshwater experimental trophic chain: A study in environmentally relevant conditions through the use of mesocosms.

    PubMed

    Bour, Agathe; Mouchet, Florence; Cadarsi, Stéphanie; Silvestre, Jérôme; Verneuil, Laurent; Baqué, David; Chauvet, Eric; Bonzom, Jean-Marc; Pagnout, Christophe; Clivot, Hugues; Fourquaux, Isabelle; Tella, Marie; Auffan, Mélanie; Gauthier, Laury; Pinelli, Eric

    2016-01-01

    The toxicity of CeO2 NPs on an experimental freshwater ecosystem was studied in mesocosm, with a focus being placed on the higher trophic level, i.e. the carnivorous amphibian species Pleurodeles waltl. The system comprised species at three trophic levels: (i) bacteria, fungi and diatoms, (ii) Chironomus riparius larvae as primary consumers and (iii) Pleurodeles larvae as secondary consumers. NP contamination consisted of repeated additions of CeO2 NPs over 4 weeks, to obtain a final concentration of 1 mg/L. NPs were found to settle and accumulate in the sediment. No effects were observed on litter decomposition or associated fungal biomass. Changes in bacterial communities were observed from the third week of NP contamination. Morphological changes in CeO2 NPs were observed at the end of the experiment. No toxicity was recorded in chironomids, despite substantial NP accumulation (265.8 ± 14.1 mg Ce/kg). Mortality (35.3 ± 6.8%) and a mean Ce concentration of 13.5 ± 3.9 mg/kg were reported for Pleurodeles. Parallel experiments were performed on Pleurodeles to determine toxicity pathways: no toxicity was observed by direct or dietary exposures, although Ce concentrations almost reached 100 mg/kg. In view of these results, various toxicity mechanisms are proposed and discussed. The toxicity observed on Pleurodeles in mesocosm may be indirect, due to microorganism's interaction with CeO2 NPs, or NP dissolution could have occurred in mesocosm due to the structural complexity of the biological environment, resulting in toxicity to Pleurodeles. This study strongly supports the importance of ecotoxicological assessment of NPs under environmentally relevant conditions, using complex biological systems.

  10. Multigenerational effects of tris(1,3-dichloro-2-propyl) phosphate on the free-living ciliate protozoa Tetrahymena thermophila exposed to environmentally relevant concentrations and after subsequent recovery.

    PubMed

    Li, Jing; Ma, Xufa; Su, Guanyong; Giesy, John P; Xiao, Yuan; Zhou, Bingsheng; Letcher, Robert J; Liu, Chunsheng

    2016-11-01

    Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is considered a re-emerging environmental pollutant, and exposure to environmentally relevant concentrations has been shown to cause individual developmental toxicity in zebrafish and the water flea (Daphnia magna). However, multigenerational effects during exposure to TDCIPP and after subsequent recovery were unknown. In the present study, individuals of a model aquatic organism, the ciliated protozoan, T. thermophila were exposed to environmentally-relevant concentrations of TDCIPP (0, 300 or 3000 ng/L) for 60 days (e.g., theoretically 372 generations) followed by a 60-day period of recovery, during which T. thermophila were not exposed to TDCIPP. During exposure and after exposure, effects at the molecular, histological, individual and population levels were examined. Multigenerational exposure to 300 or 3000 ng TDCIPP/L for 60 days significantly decreased numbers of individuals, sizes of individuals, expressed as length and width of bodies, number of cilia, and depth and diameter of basal bodies of cilia, and up-regulated expressions of genes related to assembly and maintenance of cilia. Complete or partial recoveries of theoretical sizes of populations as well as sizes of individuals and expressions of genes were observed during the 60-day recovery period. Effects on number of cilia and depth and diameter of basal body of cilia were not reversible and could still be observed long after cease of TDCIPP exposure. Collectedly, and shown for the first time, multigenerational effects to T. thermophila were caused by exposure to environmentally relevant concentrations of TDCIPP. Also, there were multi-generational effects at the population level that were not caused by carry-over exposure to TDCIPP. The "permanent" alterations and their potential significance are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Effects of Tris(1,3-dichloro-2-propyl) Phosphate on Growth, Reproduction, and Gene Transcription of Daphnia magna at Environmentally Relevant Concentrations.

    PubMed

    Li, Han; Su, Guanyong; Zou, Ming; Yu, Liqin; Letcher, Robert J; Yu, Hongxia; Giesy, John P; Zhou, Bingsheng; Liu, Chunsheng

    2015-11-03

    The synthetic flame retardant tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) has been frequently detected in natural waters, and its maximum concentration ever reported is 377 ng/L. However, information on the adverse effects of environmentally relevant concentrations of TDCIPP on aquatic organisms are totally unknown. In this study, <12-h old water fleas, D. magna, were exposed to concentrations of 0, 65±7.1, 550±33, or 6500±1400 ng/L TDCIPP, and dose- and time-dependent effects on reproduction and development were evaluated. Sequences of genes of D. magna were obtained from the National Center for Biotechnology Information and were used to develop PCR arrays for D. magna. Arrays were then used to study transcriptional responses of D. magna to TDCIPP. Exposure to environmentally relevant concentrations of TDCIPP significantly decreased fecundity as well as length of F0 and F1 generations. Transcriptional responses showed that, of the 155 genes tested, expressions of 57 genes were significantly changed, and some changes occurred following exposure to environmentally relevant concentrations (i.e., 65±7.1 and 550±23 ng/L). Furthermore, pathways related to protein synthesis and metabolism and endocytosis were considered to be significantly affected in a dose- and time-dependent manner and might be responsible for TDCIPP-induced reproductive and developmental toxicities.

  12. Human-relevant levels of added sugar consumption increase female mortality and lower male fitness in mice.

    PubMed

    Ruff, James S; Suchy, Amanda K; Hugentobler, Sara A; Sosa, Mirtha M; Schwartz, Bradley L; Morrison, Linda C; Gieng, Sin H; Shigenaga, Mark K; Potts, Wayne K

    2013-01-01

    Consumption of added sugar has increased over recent decades and is correlated with numerous diseases. Rodent models have elucidated mechanisms of toxicity, but only at concentrations beyond typical human exposure. Here we show that comparatively low levels of added sugar consumption have substantial negative effects on mouse survival, competitive ability, and reproduction. Using Organismal Performance Assays--in which mice fed human-relevant concentrations of added sugar (25% kcal from a mixture of fructose and glucose, modeling high fructose corn syrup) and control mice compete in seminatural enclosures for territories, resources and mates--we demonstrate that fructose/glucose-fed females experience a twofold increase in mortality while fructose/glucose-fed males control 26% fewer territories and produce 25% less offspring. These findings represent the lowest level of sugar consumption shown to adversely affect mammalian health. Clinical defects of fructose/glucose-fed mice were decreased glucose clearance and increased fasting cholesterol. Our data highlight that physiological adversity can exist when clinical disruptions are minor, and suggest that Organismal Performance Assays represent a promising technique for unmasking negative effects of toxicants.

  13. Study of genetic damage in the Japanese oyster induced by an environmentally-relevant exposure to diuron: evidence of vertical transmission of DNA damage.

    PubMed

    Barranger, A; Akcha, F; Rouxel, J; Brizard, R; Maurouard, E; Pallud, M; Menard, D; Tapie, N; Budzinski, H; Burgeot, T; Benabdelmouna, A

    2014-01-01

    Pesticides represent a major proportion of the chemical pollutants detected in French coastal waters and hence a significant environmental risk with regards to marine organisms. Commercially-raised bivalves are particularly exposed to pollutants, among them pesticides, as shellfish farming zones are subject to considerable pressure from agricultural activities on the mainland. The aims of this study were to determine (1) the genotoxic effects of diuron exposure on oyster genitors and (2) the possible transmission of damaged DNA to offspring and its repercussions on oyster fitness. To investigate these points, oysters were exposed to concentrations of diuron close to those detected in the Marennes-Oleron Basin (two 7-day exposure pulses at 0.4 and 0.6 μg L(-1)) during the gametogenesis period. Genomic abnormalities were characterized using two complementary approaches. The Comet assay was applied for the measurement of early and reversible primary DNA damage, whereas flow cytometry was used to assess the clastogenic and aneugenic effect of diuron exposure. Polar Organic Chemical Integrative Samplers (POCIS) were used in exposed and assay tanks to confirm the waterborne concentration of diuron reached during the experiment. The results obtained by the Comet assay clearly showed a higher level of DNA strand breaks in both the hemocytes and spermatozoa of diuron-exposed genitors. The transmission of damaged genetic material to gamete cells could be responsible for the genetic damage measured in offspring. Indeed, flow cytometry analyses showed the presence of DNA breakage and a significant decrease in DNA content in spat from diuron-exposed genitors. The transmission of DNA damage to the offspring could be involved in the negative effects observed on offspring development (decrease in hatching rate, higher level of larval abnormalities, delay in metamorphosis) and growth. In this study, the vertical transmission of DNA damage was so highlighted by subjecting oyster

  14. Estimating population health risk from low-level environmental radon

    SciTech Connect

    Fisher, D.R.

    1980-01-01

    Although incidence of respiratory cancer is directly related to inhalation of radon and radon daughters, the magnitude of the actual risk is uncertain for members of the general population exposed for long periods to low-level concentrations. Currently, any such estimate of the risk must rely on data obtained through previous studies of underground-miner populations. Several methods of risk analysis have resulted from these studies. Since the breathing atmospheres, smoking patterns, and physiology are different between miners and the general public, overestimates of lung cancer risk to the latter may have resulted. Strong evidence exists to support the theory of synergistic action between alpha radiation and other agents, and therefore a modified relative risk model was developed to predict lung cancer risks to the general public. The model considers latent period, observation period, age dependency, and inherent risks from smoking or geographical location. A test of the model showed excellent agreement with results of the study of Czechoslovakian uranium miners, for which the necessary time factors were available. The risk model was also used to predict lung cancer incidence among residents of homes on reclaimed Florida phosphate lands, and results of this analysis indicate that over the space of many years, the increased incidence of lung cancer due to elevated radon levels may be indisgtinguishable from those due to other causes.

  15. Developing a Successful State-Level Environmental Education Organization: A Nationwide Assessment

    ERIC Educational Resources Information Center

    Smaldone, David; Dey, Shannon E.

    2010-01-01

    The purpose of this study was to conduct a nationwide assessment of state-level environmental education (EE) organizations to determine the components that are essential to the establishment and success of these organizations. E-mail surveys were used to collect data from North American Association for Environmental Education state affiliates, and…

  16. Impact of a University-Level Environmental Studies Class on Students' Values

    ERIC Educational Resources Information Center

    McMillan, Emily E.; Wright, Tarah; Beazley, Karen

    2004-01-01

    This study evaluates the impact of an introductory university-level environmental studies class on the environmental values of students. Interviews and questionnaires were used to determine whether values changed or developed after taking the class. Three stage unstructured interviews were conducted throughout the academic year. Questionnaires…

  17. The Influence of Outdoor Schoolyard Experiences on Students' Environmental Knowledge, Attitudes, Behaviors, and Comfort Levels

    ERIC Educational Resources Information Center

    Martin, Sarah Carrier

    2003-01-01

    This study was designed to examine the effects of participation in regular outdoor schoolyard environmental education activities on environmental knowledge, attitudes, behaviors, and comfort levels of fourth- and fifth-grade students. Results showed that the fifth-grade treatment group showed statistically significant differences in the measures…

  18. Impact of a University-Level Environmental Studies Class on Students' Values

    ERIC Educational Resources Information Center

    McMillan, Emily E.; Wright, Tarah; Beazley, Karen

    2004-01-01

    This study evaluates the impact of an introductory university-level environmental studies class on the environmental values of students. Interviews and questionnaires were used to determine whether values changed or developed after taking the class. Three stage unstructured interviews were conducted throughout the academic year. Questionnaires…

  19. Developing a Successful State-Level Environmental Education Organization: A Nationwide Assessment

    ERIC Educational Resources Information Center

    Smaldone, David; Dey, Shannon E.

    2010-01-01

    The purpose of this study was to conduct a nationwide assessment of state-level environmental education (EE) organizations to determine the components that are essential to the establishment and success of these organizations. E-mail surveys were used to collect data from North American Association for Environmental Education state affiliates, and…

  20. Polychlorinated biphenyls (PCBs) in Africa: a review of environmental levels.

    PubMed

    Gioia, Rosalinda; Akindele, Abidemi James; Adebusoye, Sunday Adekunle; Asante, Kwadwo Ansong; Tanabe, Shinsuke; Buekens, Alfons; Sasco, Annie J

    2014-05-01

    Several studies have shown an increase in PCB sources in Africa due to leakage and wrongly disposed transformers, continuing import of e-waste from countries of the North, shipwreck, and biomass burning. Techniques used in the recycling of waste such as melting and open burning to recover precious metals make PCBs contained in waste and other semivolatile organic substances prone to volatilization, which has resulted in an increase of PCB levels in air, blood, breast milk, and fish in several regions of Africa. Consequences for workers performing these activities without adequate measures of protection could result in adverse human health effects. Recent biodegradation studies in Africa have revealed the existence of exotic bacterial strains exhibiting unique and unusual PCB metabolic capability in terms of array of congeners that can serve as carbon source and diversity of congeners attacked, marking considerable progress in the development of effective bioremediation strategies for PCB-contaminated matrices such as sediments and soils in tropical regions. Action must be taken to find and deal with the major African sources of these pollutants. The precise sources of the PCB plume should be pinned down and used to complete the pollutant inventories of African countries. These nations must then be helped to safely dispose of the potentially dangerous chemicals.

  1. Fast responsive, optical trace level ammonia sensor for environmental monitoring

    PubMed Central

    2012-01-01

    Background Ammonia is a ubiquitous chemical substance which is created in technical and biological processes and harmful to many different organisms. One specific problem is the toxicity of ammonia in fish at levels of 25 μg/l - a very common issue in today’s aqua culture. In this study we report a development of a fast responsive, optical ammonia sensor for trace concentrations. Results Different hydrogels have been investigated as host polymers for a pH based sensing mechanism based on fluorescent dyes. A porous hydrophobic fluoropolymer membrane was used as an ion barrier cover layer to achieve a good ammonia permeability. The sensor’s sensitivity towards ammonia as well as crosssensitivity towards pH-value and salinity, and the temperature dependency have been determined. Two different methods to reference fluorescence signals have been employed to eliminate intensity-based measurement drawbacks. Conclusion The presented sensor features high sensitivity and a fast response even at concentrations near 1 ppb. No cross sensitivity towards pH and salinity could be observed and temperature dependency was determined as compensateable. Both referencing approaches prove themselves to be able to provide a simple use of the sensor for in-field applications. PMID:23101725

  2. A review of occupational safety and health issues relevant to the Environmental Restoration Program: Selected case histories and associated issues

    SciTech Connect

    Lesperance, A.M.; Siegel, M.R.; McKinney, M.C.

    1994-08-01

    Since the 1940s, US Department of Energy (DOE) sites have been used for nuclear materials processing and production, warhead testing, and weapons research and development. These activities have resulted in extensive environmental contamination. DOE has established a goal to cleanup and restore the groundwater, soils, sediments, and surface water at its facilities across the nation. To achieve this goal, many workers will be needed to conduct the cleanup. These workers will need training and will be required to follow occupational safety and health (OSH) regulations and guidelines. Compliance with the OSH regulations and guidelines will have an anomous influence on the schedule, money, and technology needed for environmental restoration. Therefore, one area that must be considered in the early stages of long-term planning is the impact of OSH issues on the environmental restoration process. The DOE Office of Environmental Restoration and Waste Management has requested that the Pacific Northwest Laboratory (PNL) investigate the impact of these issues on the environmental restoration process.

  3. OCCURRENCE OF HIGH-LEVEL AMINOGLYCOSIDE RESISTANCE IN ENVIRONMENTAL ISOLATES OF ENTEROCOCCI

    EPA Science Inventory

    High-level resistance fo aminoglycosides was observed in environmental isolates of enterococci. Various aquatic habitats, including agricultural runoff, creeks, rivers, wastewater, and wells, were analyzed. Strains of Enterococcus faecalis, e.faecium, E. gallinarum, and other Ent...

  4. OCCURRENCE OF HIGH-LEVEL AMINOGLYCOSIDE RESISTANCE IN ENVIRONMENTAL ISOLATES OF ENTEROCOCCI

    EPA Science Inventory

    High-level resistance fo aminoglycosides was observed in environmental isolates of enterococci. Various aquatic habitats, including agricultural runoff, creeks, rivers, wastewater, and wells, were analyzed. Strains of Enterococcus faecalis, e.faecium, E. gallinarum, and other Ent...

  5. The Delivery System of Environmental Education at the Tertiary Level in the Asia-Pacific Region.

    ERIC Educational Resources Information Center

    Sato, Masahisa; Bhandari, Bishnu; Abe, Osamu

    2001-01-01

    Analyzes the delivery system of environmental education at the tertiary level in relation to higher education attendance rate. Describes the characteristics of the delivery system in countries such as China, India, Australia, Japan, South Korea, and Indonesia. (Author/MM)

  6. Co-operation in Environmental Education at the Tertiary Level in the Asia-Pacific Region.

    ERIC Educational Resources Information Center

    Sato, Masahisa; Bhandari, Bishnu; Abe, Osamu

    2001-01-01

    Analyzes the co-operation in environmental education at the tertiary level with regard to sub-regions, which include North-East Asia, South-East Asia, South Asia, and the South Pacific. (Contains 17 references.) (YDS)

  7. 24 CFR 35.830 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intervention blood lead level. 35.830 Section 35.830 Housing and Urban Development Office of the Secretary... intervention blood lead level. (a) Risk assessment. Within 15 days after being notified by a public health... an environmental intervention blood lead level, HUD shall complete a risk assessment of the...

  8. 24 CFR 35.830 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intervention blood lead level. 35.830 Section 35.830 Housing and Urban Development Office of the Secretary... intervention blood lead level. (a) Risk assessment. Within 15 days after being notified by a public health... an environmental intervention blood lead level, HUD shall complete a risk assessment of the...

  9. 24 CFR 35.830 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intervention blood lead level. 35.830 Section 35.830 Housing and Urban Development Office of the Secretary... intervention blood lead level. (a) Risk assessment. Within 15 days after being notified by a public health... an environmental intervention blood lead level, HUD shall complete a risk assessment of the...

  10. 24 CFR 35.830 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intervention blood lead level. 35.830 Section 35.830 Housing and Urban Development Office of the Secretary... intervention blood lead level. (a) Risk assessment. Within 15 days after being notified by a public health... an environmental intervention blood lead level, HUD shall complete a risk assessment of the...

  11. 24 CFR 35.830 - Child with an environmental intervention blood lead level.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intervention blood lead level. 35.830 Section 35.830 Housing and Urban Development Office of the Secretary... intervention blood lead level. (a) Risk assessment. Within 15 days after being notified by a public health... an environmental intervention blood lead level, HUD shall complete a risk assessment of the...

  12. Handheld Device Adapted to Smartphone Cameras for the Measurement of Sodium Ion Concentrations at Saliva-Relevant Levels via Fluorescence

    PubMed Central

    Lipowicz, Michelle; Garcia, Antonio

    2015-01-01

    The use of saliva sampling as a minimally-invasive means for drug testing and monitoring physiology is a subject of great interest to researchers and clinicians. This study describes a new optical method based on non-axially symmetric focusing of light using an oblate spheroid sample chamber. The device is simple, lightweight, low cost and is easily attached to several different brands/models of smartphones (Apple, Samsung, HTC and Nokia) for the measurement of sodium ion levels at physiologically-relevant saliva concentrations. The sample and fluorescent reagent solutions are placed in a specially-designed, lightweight device that excludes ambient light and concentrates 470-nm excitation light, from a low-power photodiode, within the sample through non-axially-symmetric refraction. The study found that smartphone cameras and post-image processing quantitated sodium ion concentration in water over the range of 0.5–10 mM, yielding best-fit regressions of the data that agree well with a data regression of microplate luminometer results. The data suggest that fluorescence can be used for the measurement of salivary sodium ion concentrations in low-resource or point-of-care settings. With further fluorescent assay testing, the device may find application in a variety of enzymatic or chemical assays.

  13. p,p'-DDE Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with o,p'-DDT.

    PubMed

    Sun, Jianxian; Wang, Chen; Peng, Hui; Zheng, Guomao; Zhang, Shiyi; Hu, Jianying

    2016-01-05

    Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations.

  14. The Interface of Environmental and Humane Education as an Emerging and Relevant Dialogue: A Point of View from Brazil

    ERIC Educational Resources Information Center

    Castellano, Maria; Quirino de Luca, Andrea; Sorrentino, Marcos

    2011-01-01

    This article addresses the interface between environmental and humane education, as a theoretical and practical emerging field in Brazil. We begin by presenting conceptual similarities that, in our view, underpin and justify the need for a growing connection between the two fields of research and educational practice. We then describe an…

  15. DETERMINATION OF PHENOLS IN ENVIRONMENTALLY RELEVANT MATRICES WITH THE USE OF LIQUID CHROMATOGRAPHY WITH AN ENZYME ELECTRODE DETECTOR

    EPA Science Inventory

    A simple and rapid assay using HPLC with a tyrosinase-containing carbon paste electrode (Tyr-CPE) detector is demonstrated for the detection of phenol, p-cresol, p-methoxyphenol, and p-chlorophenol in environmental matrices. These compounds were measured in contaminated aqueous...

  16. DETERMINATION OF PHENOLS IN ENVIRONMENTALLY RELEVANT MATRICES WITH THE USE OF LIQUID CHROMATOGRAPHY WITH AN ENZYME ELECTRODE DETECTOR

    EPA Science Inventory

    A simple and rapid assay using HPLC with a tyrosinase-containing carbon paste electrode (Tyr-CPE) detector is demonstrated for the detection of phenol, p-cresol, p-methoxyphenol, and p-chlorophenol in environmental matrices. These compounds were measured in contaminated aqueous...

  17. How relevant is environmental quality to per capita health expenditures? Empirical evidence from panel of developing countries.

    PubMed

    Yahaya, Adamu; Nor, Norashidah Mohamed; Habibullah, Muzafar Shah; Ghani, Judhiana Abd; Noor, Zaleha Mohd

    2016-01-01

    Developing countries have witnessed economic growth as their GDP keeps increasing steadily over the years. The growth led to higher energy consumption which eventually leads to increase in air pollutions that pose a danger to human health. People's healthcare demand, in turn, increase due to the changes in the socioeconomic life and improvement in the health technology. This study is an attempt to investigate the impact of environmental quality on per capital health expenditure in 125 developing countries within a panel cointegration framework from 1995 to 2012. We found out that a long-run relationship exists between per capita health expenditure and all explanatory variables as they were panel cointegrated. The explanatory variables were found to be statistically significant in explaining the per capita health expenditure. The result further revealed that CO2 has the highest explanatory power on the per capita health expenditure. The impact of the explanatory power of the variables is greater in the long-run compared to the short-run. Based on this result, we conclude that environmental quality is a powerful determinant of health expenditure in developing countries. Therefore, developing countries should as a matter of health care policy give provision of healthy air a priority via effective policy implementation on environmental management and control measures to lessen the pressure on health care expenditure. Moreover more environmental proxies with alternative methods should be considered in the future research.

  18. Level 1 environmental assessment of cupola emissions at the Tioga Foundry

    SciTech Connect

    Menzies, K.T.; Adams, J.W.; Thrun, K.E.

    1984-01-01

    Sampling and analysis was undertaken to characterize and quantify particulate, organic and inorganic chemical concentrations in gaseous effluents downstream of an afterburner (AFB) or stack air addition (SAA) system in a cupola at the Tioga Casting Company in Owego, New York. The US Environmental Protection Agency/Industrial Environmental Research Laboratory (EPA/IERL) Level 1 environmental assessment procedures were used to determine if the level of pollutants present differed when using the AFB versus the SAA control device for reduction of carbon monoxide (CO) concentrations.

  19. Carboxylic acid functionalization prevents the translocation of multi-walled carbon nanotubes at predicted environmentally relevant concentrations into targeted organs of nematode Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Nouara, Abdelli; Wu, Qiuli; Li, Yinxia; Tang, Meng; Wang, Haifang; Zhao, Yuliang; Wang, Dayong

    2013-06-01

    Carboxyl (-COOH) surface modified multi-walled carbon nanotubes (MWCNTs-COOH) can be used for targeted delivery of drugs and imaging. However, whether MWCNTs-COOH at environmentally relevant concentrations exert certain toxic effects on multicellular organisms and the underlying mechanisms are still largely unclear. In the present study, we applied the nematode Caenorhabditis elegans to evaluate the properties of MWCNTs-COOH at environmentally relevant concentrations by comparing the effects of MWCNTs and MWCNTs-COOH exposure on C. elegans from L1-larvae to adult at concentrations of 0.001-1000 μg L-1. Exposure to MWCNTs could potentially damage the intestine (primary targeted organ) at concentrations greater than 0.1 μg L-1 and functions of neurons and reproductive organ (secondary targeted organs) at concentrations greater than 0.001 μg L-1. Carboxyl modification prevented the toxicity of MWCNTs on the primary and the secondary targeted organs at concentrations less than 100 μg L-1, suggesting that carboxyl modification can effectively prevent the adverse effects of MWCNTs at environmentally relevant concentrations. After exposure, MWCNTs-COOH (1 mg L-1) were translocated into the spermatheca and embryos in the body through the primary targeted organs. However, MWCNTs-COOH (10 μg L-1) were not observed in spermatheca and embryos in the body of nematodes. Moreover, relatively high concentrations of MWCNTs-COOH exposed nematodes might have a hyper-permeable intestinal barrier, whereas MWCNTs-COOH at environmentally relevant concentrations effectively sustained the normally permeable state for the intestinal barrier. Therefore, we elucidated the cellular basis of carboxyl modification to prevent toxicity of MWCNTs at environmentally relevant concentrations. Our data highlights the key role of biological barriers in the primary targeted organs to block toxicity formation from MWCNTs, which will be useful for the design of effective prevention strategies against

  20. Factors affecting the bioavailability of soy isoflavones in humans after ingestion of physiologically relevant levels from different soy foods.

    PubMed

    Cassidy, Aedin; Brown, Jonathan E; Hawdon, Anne; Faughnan, Marian S; King, Laurence J; Millward, Joe; Zimmer-Nechemias, Linda; Wolfe, Brian; Setchell, Kenneth D R

    2006-01-01

    The precise role that isoflavones play in the health-related effects of soy foods, and their potential for adverse effects are controversial. This may be due in part to a lack of basic knowledge regarding their bioavailability and metabolism, particularly as it relates to the soy source. To date, there is little information concerning possible differences in the bioavailability of isoflavones derived from natural soy foods consumed at physiologically relevant intakes and whether age- or gender-related differences influence that bioavailability. In the current study of healthy adults [premenopausal (n = 21) and postmenopausal (n = 17) women and a group of men (n = 21)], we examined the effect of age, gender, and the food matrix on the bioavailability of isoflavones for both the aglycon and glucoside forms that are naturally present in 3 different soy foods, soy milk, textured vegetable protein, and tempeh. The study was designed as a random crossover trial so that all individuals received each of the 3 foods. The dose of isoflavones administered to each individual as a single bolus dose was 0.44 mg/kg body weight. Pharmacokinetic parameters were normalized to mg of each isoflavone ingested per kilogram body weight to account for differences in daidzein and genistein content between the diets. Serum isoflavone concentrations in all individuals and groups increased rapidly after the ingestion of each soy food; as expected, genistein concentrations exceeded daidzein concentrations in serum. In this small study, gender differences in peak concentrations of daidzein were observed, with higher levels attained in women. Consumption of tempeh (mainly isoflavone aglycon) resulted in higher serum peak levels of both daidzein (P < 0.001) and genistein (P < 0.01) and the associated area under the curve (P < 0.001 and P < 0.03, respectively) compared with textured vegetable protein (predominantly isoflavone glucosides). However, soy milk was absorbed faster and peak levels of

  1. Blood lead and cadmium levels and relevant factors among children from an e-waste recycling town in China

    SciTech Connect

    Zheng Liangkai; Wu Kusheng; Li Yan; Qi Zongli; Han Dai; Zhang Bao; Gu Chengwu; Chen Gangjian; Liu Junxiao; Chen Songjian; Xu Xijin; Huo Xia

    2008-09-15

    Background: Primitive electronic waste (e-waste) recycling is ongoing in Guiyu, and thus toxic heavy metals may keep on threatening to the health of local children. Some related factors may contribute to the elevation of blood lead levels (BLLs) or blood cadmium levels (BCLs). Objective: To investigate the children's BLLs and BCLs in Guiyu and Chendian as compare to discuss the effects of primitive e-waste recycling activities on children's health. Methods: Two hundred and seventy-eight children less than 8 years who lived in Guiyu and Chendian were observed, and their BLLs and BCLs were determined by graphite atomizer absorption spectrophotometer. Questionnaire survey for risk factors was also performed and data were analyzed using spearman correlation analyses and logistic regression analyses. Results: Children living in Guiyu had significantly higher BLLs and BCLs as compared with those living in Chendian (p<0.01). In Guiyu, 70.8% of children (109/154) had BLLs>10 {mu}g/dL, and 20.1% of children (31/154) had BCLs>2 {mu}g/L, compared with 38.7% of children (48/124) had BLLs>10 {mu}g/dL and 7.3% of children (9/124) had BCLs>2 {mu}g/L in Chendian (p<0.01, respectively). We also observed a significant increasing trend in BLLs with increasing age in Guiyu (p<0.01). Mean height of children in Guiyu was significantly lower than that in Chendian (p<0.01). The risk factors related to children's BLLs and BCLs mainly included father's engagement in the work related to e-waste, children's residence in Guiyu and the amount of time that children played outside near the road everyday. Conclusions: There are close relationships between the BLLs, BCLs in children and the primitive e-waste recycling activities in Guiyu. Environmental pollution, especially lead pollution, has threatened the health of children living around e-waste recycling site.

  2. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    SciTech Connect

    Etnier, E.L.; Eaton, L.A. )

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms applicable'' and relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed.

  3. Environmental levels of Linear alkylbenzene Sulfonates (LAS) in sediments from the Tagus estuary (Portugal): environmental implications.

    PubMed

    Hampel, M; Canário, J; Branco, V; Vale, C; Blasco, J

    2009-02-01

    Sediments from the Tagus estuary (Portugal) were collected at 40 stations in July and December 2004. Total LAS concentrations ranged between 0.03 and 17.76 mg LAS.kg(-1) dry weight in July, and between 0.09 and 9.57 mg LAS.kg(-1) in December. Highest LAS concentrations were found at the upper northern part of the estuary, coincident with the localisation of an important waste water treatment station. According to the Predicted No Effect Concentration (PNEC) of 8.1 mg.kg(-1) derived for this compound, Environmental Risk Assessment (ERA) identified a hazard for the ecosystem at the station with the highest LAS concentration, and similar results are obtained by Equilibrium Partitioning Method (EPM). Nevertheless, LAS concentrations decreased significantly between samplings in the stations with the highest LAS concentrations in July, whereas increased LAS concentrations at adjacent stations were found in December. In the remaining stations, LAS concentrations were up to three orders of magnitude lower, representing no hazard for the sediment community.

  4. Bringing Sharper Focus to Environmental Education at the State Level in the Reauthorization of the National Environmental Education Act.

    ERIC Educational Resources Information Center

    Lefebvre, Guy N.

    The National Environmental Education Act became law on November 16, 1990. The major sections of this law establish a national environmental education office, an environmental education and training program, environmental education grants, environmental internships and fellowships, environmental education awards, and an environmental education…

  5. Skill acquisition while operating in-vehicle information systems: interface design determines the level of safety-relevant distractions.

    PubMed

    Jahn, Georg; Krems, Josef F; Gelau, Christhard

    2009-04-01

    This study tested whether the ease of learning to use human-machine interfaces of in-vehicle information systems (IVIS) can be assessed at standstill. Assessing the attentional demand of IVIS should include an evaluation of ease of learning, because the use of IVIS at low skill levels may create safety-relevant distractions. Skill acquisition in operating IVIS was quantified by fitting the power law of practice to training data sets collected in a driving study and at standstill. Participants practiced manual destination entry with two route guidance systems differing in cognitive demand. In Experiment 1, a sample of middle-aged participants was trained while steering routes of varying driving demands. In Experiment 2, another sample of middle-aged participants was trained at standstill. In Experiment 1, display glance times were less affected by driving demands than by total task times and decreased at slightly higher speed-up rates (0.02 higher on average) than task times collected at standstill in Experiment 2. The system interface that minimized cognitive demand was operated more quickly and was easier to learn. Its system delays increased static task times, which still predicted 58% of variance in display glance times compared with even 76% for the second system. The ease of learning to use an IVIS interface and the decrease in attentional demand with training can be assessed at standstill. Fitting the power law of practice to static task times yields parameters that predict display glance times while driving, which makes it possible to compare interfaces with regard to ease of learning.

  6. Effects of eye rubbing on the levels of protease, protease activity and cytokines in tears: relevance in keratoconus.

    PubMed

    Balasubramanian, Sivaraman A; Pye, David C; Willcox, Mark D P

    2013-03-01

    Proteases, protease activity and inflammatory molecules in tears have been found to be relevant in the pathogenesis of keratoconus. We sought to determine the influence of eye rubbing on protease expression, protease activity and concentration of inflammatory molecules in tears. Basal tears were collected from normal volunteers before and after 60 seconds of experimental eye rubbing. The total amount of matrix metalloproteinase (MMP)-13 and inflammatory molecules interleukin (IL)-6 and tumour necrosis factor (TNF)-α in the tear samples were measured using specific enzyme-linked immunosorbent assays (ELISA). Tear collagenase activity was investigated using a specific activity assay. The concentrations of MMP-13 (51.9 ± 34.3 versus 63 ± 36.8 pg/ml, p = 0.006), IL-6 (1.24 ± 0.98 versus 2.02 ± 1.52 pg/ml, p = 0.004) and TNF-α (1.16 ± 0.74 versus 1.44 ± 0.66 pg/ml, p = 0.003) were significantly increased in normal subjects after eye rubbing. The experimental eye rub did not alter significantly the collagenase activity (5.02 ± 3 versus 7.50 ± 3.90 fluorescent intensity units, p = 0.14) of tears. Eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-α in normal study subjects. This increase in protease, protease activity and inflammatory mediators in tears after eye rubbing may be exacerbated even further during persistent and forceful eye rubbing seen in people with keratoconus and this in turn may contribute to the progression of the disease. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

  7. High Environmental Ozone Levels Lead to Enhanced Allergenicity of Birch Pollen

    PubMed Central

    Beck, Isabelle; Jochner, Susanne; Gilles, Stefanie; McIntyre, Mareike; Buters, Jeroen T. M.; Schmidt-Weber, Carsten; Behrendt, Heidrun; Ring, Johannes; Menzel, Annette; Traidl-Hoffmann, Claudia

    2013-01-01

    Background Evidence is compelling for a positive correlation between climate change, urbanisation and prevalence of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergenic effect of anthropogenic factors on susceptible individuals. Objectives To evaluate the impact of urbanisation and climate change on pollen allergenicity. Methods Catkins were sampled from birch trees from different sites across the greater area of Munich, pollen were isolated and an urbanisation index, NO2 and ozone exposure were determined. To estimate pollen allergenicity, allergen content and pollen-associated lipid mediators were measured in aqueous pollen extracts. Immune stimulatory and modulatory capacity of pollen was assessed by neutrophil migration assays and the potential of pollen to inhibit dendritic cell interleukin-12 response. In vivo allergenicity was assessed by skin prick tests. Results The study revealed ozone as a prominent environmental factor influencing the allergenicity of birch pollen. Enhanced allergenicity, as assessed in skin prick tests, was mirrored by enhanced allergen content. Beyond that, ozone induced changes in lipid composition and chemotactic and immune modulatory potential of the pollen. Higher ozone-exposed pollen was characterised by less immune modulatory but higher immune stimulatory potential. Conclusion It is likely that future climate change along with increasing urbanisation will lead to rising ozone concentrations in the next decades. Our study indicates that ozone is a crucial factor leading to clinically relevant enhanced allergenicity of birch pollen. Thus, with increasing temperatures and increasing ozone levels, also symptoms of pollen allergic patients may increase further. PMID:24278250

  8. NEA Research and Environmental Surveillance Programme related to sea disposal of low-level radioactive waste

    SciTech Connect

    Ruegger, B.; Templeton, W.L.; Gurbutt, P.

    1983-05-01

    Sea dumping operations of certain types of packaged low and medium-level radioactive wastes have been carried out since 1967 in the North-East Atlantic under the auspices of the OECD Nuclear Energy Agency. On the occasion of the 1980 review of the continued suitability of the North-East Atlantic site used for the disposal of radioactive waste, it was recommended that an effort should be made to increase the scientific data base relating to the oceanographic and biological characteristics of the dumping area. In particular, it was suggested that a site specific model of the transfer of radionuclides in the marine environment be developed, which would permit a better assessment of the potential radiation doses to man from the dumping of radioactive waste. To fulfill these objectives a research and environmental surveillance programme related to sea disposal of radioactive waste was set up in 1981 with the participation of thirteen Member countries and the International Laboratory for Marine Radioactivity of the IAEA in Monaco. The research program is focused on five research areas which are directly relevant to the preparation of more site-specific assessments in the future. They are: model development; physical oceanography; geochemistry; biology; and radiological surveillance. Promising results have already been obtained and more are anticipated in the not too distant future. An interim description of the NEA dumping site has been prepared which provides an excellent data base for this area (NEA 1983).It includes data in bathymetry, isopycnal topography, local and larger scale currents, sediment distribution and sedimentary processes, hydrochemistry, deep ocean biology and results of radiochemical analyses of sea water, sediments and biological materials. The modelling work is also well advanced allowing comparison of results obtained from different codes. After integration of the models, sensitivity analyses will provide indications for future research needs.

  9. The Relationship between Pre-Service Teachers' Awareness Levels of Electromagnetic Pollution and Other Environmental Problems

    ERIC Educational Resources Information Center

    Koklukaya, Ayse Nesibe; Guven Yildirim, Ezgi; Selvi, Mahmut

    2017-01-01

    Purpose: The purpose of this study is to find out the relationship between the awareness level of preservice science teachers' conscious use of technological devices, which cause electromagnetic pollution, and their awareness level of related environmental problems. Research Methods: In this study, a mixed design method was used. A relational…

  10. Impact of TiO₂ and ZnO nanoparticles at predicted environmentally relevant concentrations on ammonia-oxidizing bacteria cultures under ammonia oxidation.

    PubMed

    Luo, Zhuanxi; Qiu, Zhaozheng; Chen, Zheng; Du Laing, Gijs; Liu, Aifen; Yan, Changzhou

    2015-02-01

    Increased application of titanium dioxide and zinc oxide nanoparticles (nano-TiO2 and nano-ZnO) raises concerns related to their environmental impacts. The effects that such nanoparticles have on environmental processes and the bacteria that carry them out are largely unknown. In this study, ammonia-oxidizing bacteria (AOB) enrichment cultures, grown from surface sediments taken from an estuary wetland in Fujian Province, China, were spiked with nano-TiO2 and nano-ZnO (with an average size of 32 and 43 nm, respectively) at predicted environmentally relevant concentrations (≤2 mg L(-1)) to determine their impacts on ammonia oxidation and the mechanisms involved. Results showed that higher nano-TiO2 concentrations significantly inhibited ammonia oxidation in enrichment cultures. It is noteworthy that the average ammonia oxidation rate was significantly correlated to the Shannon index, the Simpson's index, and AOB abundance. This suggested that ammonia oxidation inhibition primarily resulted from a reduction of AOB biodiversity and abundance. However, AOB biodiversity and abundance as well as the average ammonia oxidation rate were not inhibited by nano-ZnO at predicted environmentally relevant concentrations. Accordingly, an insignificant correlation was established between biodiversity and abundance of the AOB amoA gene and the average ammonia oxidation rate under nano-ZnO treatments. AOB present in samples belonged to the β-Proteobacteria class with an affinity close to Nitrosospira and Nitrosomonas genera. This suggested that identified impacts of nano-TiO2 and nano-ZnO on ammonia oxidation processes can be extrapolated to some extent to natural aquatic environments. Complex impacts on AOB may result from different nanomaterials present in aquatic environments at various ambient conditions. Further investigation on how and to what extent different nanomaterials influence AOB diversity and abundance and their subsequent ammonia oxidation processes is therefore

  11. Xanthan Exopolysaccharide: Cu(2+) Complexes Affected from the pH-Dependent Conformational State; Implications for Environmentally Relevant Biopolymers.

    PubMed

    Causse, Benjamin; Spadini, Lorenzo; Sarret, Géraldine; Faure, Adeline; Travelet, Christophe; Madern, Dominique; Delolme, Cécile

    2016-04-05

    The conformational impact of environmental biopolymers on metal sorption was studied through Cu sorption on xanthan. The apparent Cu(2+) complexation constant (logK; Cu(2+) + L(-) ↔ CuL(+)) decreased from 2.9 ± 0.1 at pH 3.5 to 2.5 ± 0.1 at pH 5.5 (ionic strength I = 0.1). This behavior is in apparent contradiction with basic thermodynamics, as usually the higher the pH the more cations bind. Our combined titration, circular dichroism and dynamic light scattering study indicated that the change observed in Cu bond strength relates to a conformational change of the structure of xanthan, which generates more chelating sites at pH 3.5 than at pH 5.5. This hypothesis was validated by the fact that the Cu sorption constants on xanthan were always higher than those measured on a mixture of pyruvic and glucuronic acids (logK = 2.2), which are the two constitutive ligands present in the xanthan monomer. This study shows the role of the structural conformation of natural biopolymers in metal bond strength. This finding may help to better predict the fate of Cu and other metals in acidic environmental settings such as aquatic media affected by acid mine drainage, as well as peats and acidic soils, and to better define optimal conditions for bioremediation processes.

  12. Inhibition of cholinesterase activity by soil extracts and predicted environmental concentrations (PEC) to select relevant pesticides in polluted soils.

    PubMed

    Meza, Juan C Sanchez; Perez, Pedro Avila; Salin, Manuel Borja; Salazar, Victor F Pacheco; Lapoint, Tom

    2010-04-01

    The correlation of predicted environmental concentrations (PEC) with cholinesterase activity inhibition detected in soil extracts was determined. PEC was derived from organophosphate (OP) and carbamate (CA) compounds applied to a flower crop area. Samples of surface soil (0 - 30 cm in depth) and subsurface soil (30 to 60 cm in depth) were taken from a flower crop area in which OP pesticides such as acephate ((RS)-N-[methoxy(methylthio)phosphinoyl]acetamide), dimethoate (2-dimethoxyphosphinothioylthio-N-methylacetamide) and methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate), and CA pesticides such as carbendazim (methyl benzimidazol-2-ylcarbamate), carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) and methomyl (S-methyl (EZ)-N-(methylcarbamoyloxy) thioacetimidate) were applied for two years. Weekly loads of these pesticides were registered to estimate the annual load of each compound. Physicochemical analysis and relative inhibition of cholinesterasic activity were measured for each soil sample. PEC values were estimated with Pesticide Analytical Model (PESTAN), a leach model, for each pesticide using soil sample data obtained from physicochemical analysis. From all pesticides tested, only acephate and methomyl showed a significant correlation (p < 0.01) between PEC values and inhibition cholinesterase activity of soil extracts. These results suggest that inhibition of cholinesterase activity observed in soil extracts is produced mainly by these two pesticides. Further studies could be developed to measure acephate and methomyl concentrations to reduce their environmental impact.

  13. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems.

  14. A relevant exposure to a food matrix contaminated environmentally by polychlorinated biphenyls induces liver and brain disruption in rats.

    PubMed

    Ounnas, Fayçal; Privé, Florence; Lamarche, Fréderic; Salen, Patricia; Favier-Hininger, Isabelle; Marchand, Philippe; Le Bizec, Bruno; Venisseau, Anais; Batandier, Cécile; Fontaine, Eric; de Lorgeril, Michel; Demeilliers, Christine

    2016-10-01

    Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants present in dietary fats. Most studies evaluating PCB effects have been conducted with a single compound or a mixture of PCBs given as a single acute dose. The purpose of this study was to evaluate in vivo PCB toxicity in a realistic model of exposure: a low daily dose of PCBs (twice the tolerable daily intake (TDI)), chronically administered (8 weeks) to rats in contaminated goat milk. Liver and brain PCB toxicities were investigated by evaluating oxidative stress status and mitochondrial function. PCB toxicity in the liver was also estimated by transaminase enzymatic activity. This study shows that even at low doses, chronic PCB exposure resulted in a statistically significant reduction of mitochondrial function in liver and brain. In the liver, oxygen consumption in the condition of adenosine triphosphate (ATP) production (state 3) decreased by 22-29% (p < 0.01), according to the respiratory substrates. In the brain, respiratory chain complexes II and III were reduced by 24% and 39%, respectively (p < 0.005). The exposed rats presented higher lipid peroxidation status (+20%, p < 0.05) and transaminase activity (+30%, p < 0.05) in the blood. Thus, our study showed that exposure of rats to a daily realistic dose of PCBs (twice the TDI in a food complex mixture of environmental origin) resulted in multiple disruptions in the liver and brain.

  15. The relevance of large scale environmental research infrastructures from the point of view of Ethics: the case of EMSO

    NASA Astrophysics Data System (ADS)

    Favali, Paolo; Beranzoli, Laura; Best, Mairi; Franceschini, PierLuigi; Materia, Paola; Peppoloni, Silvia; Picard, John

    2014-05-01

    EMSO (European Multidisciplinary Seafloor and Water Column Observatory) is a large-scale European Research Infrastructure (RI). It is a geographically distributed infrastructure composed of several deep-seafloor and water-column observatories, which will be deployed at key sites in European waters, spanning from the Arctic, through the Atlantic and Mediterranean, to the Black Sea, with the basic scientific objective of real-time, long-term monitoring of environmental processes related to the interaction between the geosphere, biosphere and hydrosphere. EMSO is one of the environmental RIs on the ESFRI roadmap. The ESRFI Roadmap identifies new RIs of pan-European importance that correspond to the long term needs of European research communities. EMSO will be the sub-sea segment of the EU's large-scale Earth Observation program, Copernicus (previously known as GMES - Global Monitoring for Environment and Security) and will significantly enhance the observational capabilities of European member states. An open data policy compliant with the recommendations being developed within the GEOSS initiative (Global Earth Observation System of Systems) will allow for shared use of the infrastructure and the exchange of scientific information and knowledge. The processes that occur in the oceans have a direct impact on human societies, therefore it is crucial to improve our understanding of how they operate and interact. To encompass the breadth of these major processes, sustained and integrated observations are required that appreciate the interconnectedness of atmospheric, surface ocean, biological pump, deep-sea, and solid-Earth dynamics and that can address: • natural and anthropogenic change; • interactions between ecosystem services, biodiversity, biogeochemistry, physics, and climate; • impacts of exploration and extraction of energy, minerals, and living resources; • geo-hazard early warning capability for earthquakes, tsunamis, gas-hydrate release, and slope

  16. Technical approach to finalizing sensible soil cleanup levels at the Fernald Environmental Management Project

    SciTech Connect

    Carr, D.; Hertel, B.; Jewett, M.; Janke, R.; Conner, B.

    1996-02-01

    The remedial strategy for addressing contaminated environmental media was recently finalized for the US Department of Energy`s (DOE) Fernald Environmental Management Project (FEMP) following almost 10 years of detailed technical analysis. The FEMP represents one of the first major nuclear facilities to successfully complete the Remedial Investigation/Feasibility Study (RI/FS) phase of the environmental restoration process. A critical element of this success was the establishment of sensible cleanup levels for contaminated soil and groundwater both on and off the FEMP property. These cleanup levels were derived based upon a strict application of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulations and guidance, coupled with positive input from the regulatory agencies and the local community regarding projected future land uses for the site. The approach for establishing the cleanup levels was based upon a Feasibility Study (FS) strategy that examined a bounding range of viable future land uses for the site. Within each land use, the cost and technical implications of a range of health-protective cleanup levels for the environmental media were analyzed. Technical considerations in driving these cleanup levels included: direct exposure routes to viable human receptors; cross- media impacts to air, surface water, and groundwater; technical practicality of attaining the levels; volume of affected media; impact to sensitive environmental receptors or ecosystems; and cost. This paper will discuss the technical approach used to support the finalization of the cleanup levels for the site. The final cleanup levels provide the last remaining significant piece to the puzzle of establishing a final site-wide remedial strategy for the FEMP, and positions the facility for the expedient completion of site-wide remedial activities.

  17. Improving environmental performance through unit-level organizational citizenship behaviors for the environment: A capability perspective.

    PubMed

    Alt, Elisa; Spitzeck, Heiko

    2016-11-01

    Organizational citizenship behaviors for the environment (OCBEs) are increasingly advocated as a means of complementing formal practices in improving environmental performance. Adopting a capability perspective, we propose that a firm's employee involvement capability translates into environmental performance through the manifestation of unit-level OCBEs, and that this relationship is amplified by a shared vision capability. In a cross-country and multi-industry sample of 170 firms, we find support for our hypotheses, shedding light on contextual determinants of OCBEs, and on how firms may engender a positive relationship between top-down environmental initiatives and bottom-up behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. A review of occupational safety and health issues relevant to the environmental restoration program: Selected case histories and associated issues

    SciTech Connect

    Lesperance, A.M.; Siegel, M.R.; McKinney, M.D.

    1992-10-01

    This report describes a study conducted by Pacific Northwest Laboratory (PNL) to determine the impact of occupational safety and health (OSH) issues on the environmental restoration process at US Department of Energy sites. PNL selected three remediation projects to study: (1) the 618-9 Burial Ground Expedited Removal Action at the Hanford Site, (2) the Chemical Consolidation Interim Response Action at the Weldon Spring Site, (3) and the 200 West Area Carbon Tetrachloride Expedited Removal Action and VOC-Arid Integration Demonstration at the Hanford Site. The first two case studies involve sites where a remediation activity has been complete. The third case study involves a remediation activity in its early stages of development. This study identifies OSH issues related to actual cleanup, time, documentation, training, and technology development. These issues need to be considered by DOE before making long-term planning efforts. Section 4.0 of this report describes recommendations for addressing these issues.

  19. Annotated bibliography of environmentally relevant investigations of uranium mining and milling in the Grants Mineral Belt, northwestern New Mexico

    USGS Publications Warehouse

    Otton, James K.

    2011-01-01

    Studies of the natural environment in the Grants Mineral Belt in northwestern New Mexico have been conducted since the 1930s; however, few such investigations predate uranium mining and milling operations, which began in the early 1950s. This report provides an annotated bibliography of reports that describe the hydrology and geochemistry of groundwaters and surface waters and the geochemistry of soils and sediments in the Grants Mineral Belt and contiguous areas. The reports referenced and discussed provide a large volume of information about the environmental conditions in the area after mining started. Data presented in many of these studies, if evaluated carefully, may provide much basic information about the baseline conditions that existed over large parts of the Grants Mineral Belt prior to mining. Other data may provide information that can direct new work in efforts to discriminate between baseline conditions and the effects of the mining and milling on the natural environment.

  20. Radiological background levels found on glass fiber filters used for low-level environmental surveillance air sampling

    SciTech Connect

    Althouse, P. E.

    1998-09-16

    Environmental surveillance of low-level radioactive particles in air requires a thorough understanding of low-level techniques and air sample collection media. High-volume air sampling for radioactive particles around Lawrence Livermore National Laboratory (LLNL) employs glass-fiber filters that are analyzed for gross alpha and gross beta activity and for specific isotopes. This study was conducted to determine the activities of radionuclides contained in blank glass-fiber filters. Data from this study provided a partial explanation of differences between current reported concentrations of radionuclides in air and those reported historically when cellulose filters were used in the LLNL monitoring effort.

  1. Assessing environmental impacts of genetically modified plants on non-target organisms: The relevance of in planta studies.

    PubMed

    Arpaia, Salvatore; Birch, A Nicholas E; Kiss, Jozsef; van Loon, Joop J A; Messéan, Antoine; Nuti, Marco; Perry, Joe N; Sweet, Jeremy B; Tebbe, Christoph C

    2017-04-01

    In legal frameworks worldwide, genetically modified plants (GMPs) are subjected to pre-market environmental risk assessment (ERA) with the aim of identifying potential effects on the environment. In the European Union, the EFSA Guidance Document introduces the rationale that GMPs, as well as their newly produced metabolites, represent the potential stressor to be evaluated during ERA. As a consequence, during several phases of ERA for cultivation purposes, it is considered necessary to use whole plants or plant parts in experimental protocols. The importance of in planta studies as a strategy to address impacts of GMPs on non-target organisms is demonstrated, to evaluate both effects due to the intended modification in plant phenotype (e.g. expression of Cry proteins) and effects due to unintended modifications in plant phenotype resulting from the transformation process (e.g. due to somaclonal variations or pleiotropic effects). In planta tests are also necessary for GMPs in which newly expressed metabolites cannot easily be studied in vitro. This paper reviews the scientific literature supporting the choice of in planta studies as a fundamental tool in ERA of GMPs in cultivation dossiers; the evidence indicates they can realistically mimic the ecological relationships occurring in their receiving environments and provide important insights into the biology and sustainable management of GMPs.

  2. Effect of environmentally-relevant concentrations of nonylphenol on sexual differentiation in zebrafish: a multi-generational study

    NASA Astrophysics Data System (ADS)

    Sun, Dong; Chen, Qi; He, Ning; Diao, Pan-Pan; Jia, Li-Xing; Duan, Shun-Shan

    2017-02-01

    Nonylphenol (NP) is a persistent environmental chemical that can disrupt the organism’s endocrine system, and is detected in the surface water and sea. In this study, we investigated whether NP can alter transcriptional expression of sexual differentiation-related genes. Three generations of zebrafish were exposed to 0, 2, 20 and 200 μg·L‑1 of NP, and transcriptional expression of sexual differentiation genes were assessed in 10, 20 and 40 dpf in the F1 and F2 generations. Growth of zebrafish exposed to 200 μg·L‑1 of NP was inhibited at 125 dpf in the F1 generation. 20 μg·L‑1 of NP resulted in 80% females in the F1 generation, but had no effect on the F2 generation. In terms of the sexual differentiation genes, the transcriptional expression of cyp19a1a and esr1 genes were upregulated in 20 μg·L‑1 of NP in the F1 generation. But expression of the sexual differentiation genes were not affected in the F2 generation. Overall, NP could affect sexual differentiation and gene transcriptional expression in the F1 generation. The tolerance of contaminant in the offsprings was improved at low concentration.

  3. A protocol to assess the enzymatic release of dissolved organic phosphorus species in waters under environmentally relevant conditions.

    PubMed

    Monbet, Phil; McKelvie, Ian D; Saefumillah, Asep; Worsfold, Paul J

    2007-11-01

    A protocol to assess the potential release of dissolved reactive phosphorus (DRP) by enzymatic hydrolysis of dissolved organic phosphorus (DOP) in waters (sediment porewater and sewage liquors in this study) under environmental conditions is presented. This protocol enables the quantification of different classes of DOP compounds using a variety of phosphatase enzymes, i.e., alkaline phosphatase, phosphodiesterase, and phytase. All experiments were carried out within the pH range of most natural waters, i.e., at neutral (pH 7) or slightly alkaline pH (pH 9). Tri-sodium citrate and sodium dodecyl sulfate (SDS) were used in the assays to prevent interferences due to adsorption processes in the presence of multivalent metallic cations and to minimize protein binding. Applying this protocol revealed that labile phosphate monoesters always represented the largest fraction of enzymatically hydrolyzed P in sewage liquors and sediment porewater. Total enzymatically hydrolyzable P (EHP) represented only 16% of the TDP in the sediment porewater but up to 43% in sewage liquors. Because most of the enzymes used in this study are likely to exist in aquatic ecosystems, the EHP fraction might represent a source of potentially bioavailable P of similar magnitude to DRP.

  4. Effect of environmentally-relevant concentrations of nonylphenol on sexual differentiation in zebrafish: a multi-generational study

    PubMed Central

    Sun, Dong; Chen, Qi; He, Ning; Diao, Pan-pan; Jia, Li-xing; Duan, Shun-shan

    2017-01-01

    Nonylphenol (NP) is a persistent environmental chemical that can disrupt the organism’s endocrine system, and is detected in the surface water and sea. In this study, we investigated whether NP can alter transcriptional expression of sexual differentiation-related genes. Three generations of zebrafish were exposed to 0, 2, 20 and 200 μg·L−1 of NP, and transcriptional expression of sexual differentiation genes were assessed in 10, 20 and 40 dpf in the F1 and F2 generations. Growth of zebrafish exposed to 200 μg·L−1 of NP was inhibited at 125 dpf in the F1 generation. 20 μg·L−1 of NP resulted in 80% females in the F1 generation, but had no effect on the F2 generation. In terms of the sexual differentiation genes, the transcriptional expression of cyp19a1a and esr1 genes were upregulated in 20 μg·L−1 of NP in the F1 generation. But expression of the sexual differentiation genes were not affected in the F2 generation. Overall, NP could affect sexual differentiation and gene transcriptional expression in the F1 generation. The tolerance of contaminant in the offsprings was improved at low concentration. PMID:28230098

  5. Differential binding of cytokines to environmentally relevant particles: a possible source for misinterpretation of in vitro results?

    PubMed

    Kocbach, A; Totlandsdal, A I; Låg, M; Refsnes, M; Schwarze, P E

    2008-01-30

    Inflammation is considered as a key event in adverse health effects associated with exposure to ambient particulate matter. The inflammatory potential of particles is often compared using in vitro cell systems, where the particle-induced release of pro-inflammatory cytokines is measured. A major concern in these assays is the potential of particles to bind cytokines, which may lead to an underestimation of the inflammatory potential. We therefore investigated the cytokine binding to a selection of particle samples, including particles collected from outdoor sources (wood combustion, traffic) and particles commonly used to model environmental sources (ultrafine carbon black, diesel, quartz), for a range of pro-inflammatory cytokines (TNF-alpha, IL-1beta, IL-6, IL-8). Furthermore, the influence of serum proteins and particle- and cytokine concentrations on the cytokine binding was studied. Cytokines primarily bound to carbonaceous particles (up to 85%), not to mineral particles. Furthermore, depending on the type of cytokine, the cytokine binding could be reduced partly or completely by adding serum proteins to the cell growth medium or particle suspensions. Based on these observations we recommend either to adjust culturing and exposure conditions to prevent cytokine binding, or to adjust the measured cytokine release by application of correction factors obtained from cytokine binding experiments.

  6. Impaired maturation, fertilization, and embryonic development of porcine oocytes following exposure to an environmentally relevant organochlorine mixture.

    PubMed

    Campagna, C; Sirard, M A; Ayotte, P; Bailey, J L

    2001-08-01

    The reproductive health risks related to exposure to persistent organic pollutants in the environment remain controversial. This debate is partly because most studies have investigated only one or two chemicals at a time, whereas populations are exposed to a large spectrum of persistent chemicals in their environment. Using the pig as a toxicological model, we hypothesized that exposing immature cumulus-oocyte complexes to an organochlorine mixture during in vitro maturation (IVM) would adversely affect oocyte maturation, fertilization, and subsequent embryo development. This organochlorine mixture mimics that which contaminates the Arctic marine food chain. Cumulus-oocyte complexes were cultured in IVM medium containing increasing concentrations of the organochlorine mixture, similar to that found in women of highly exposed populations. Organochlorines reduced the quality of cumulus expansion and the viability of cumulus cells in a dose-response manner. The proportion of apoptotic cumulus cells also increased due to organochlorine exposure. Half of the oocytes were fixed after insemination, and the remainders were cultured for 8 days. Concentrations of organochlorines did not affect the rates of oocyte degeneration, sperm penetration, and development to morula. However, incidence of incompletely matured oocytes increased and polyspermy rate decreased, both in a dose-response manner with increasing organochlorine concentrations. Blastocyst formation and number of cells per blastocyst declined with organochlorine concentration. Exposing porcine cumulus-oocyte complexes to an environmentally pertinent organochlorine mixture during IVM disturbs oocyte development, supporting recent concerns that such pollutants harm reproductive health in humans and other mammalian species.

  7. Measurements of activation induced by environmental neutrons using ultra low-level gamma-ray spectrometry.

    PubMed

    Martínez Canet, M J; Hult, M; Köhler, M; Johnston, P N

    2000-03-01

    The flux of environmental neutrons is being studied by activation of metal discs of selected elements. Near the earth's surface the total neutron flux is in the order of 10(-2) cm(-2)s(-1), which gives induced activities of a few mBq in the discs. Initial results from this technique, involving activation at ground level for several materials (W, Au, Ta, In, Re, Sm, Dy and Mn) and ultra low-level gamma-ray spectrometry in an underground laboratory located at 500 m.w.e., are presented. Diffusion of environmental neutrons in water is also measured by activation of gold at different depths.

  8. Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects.

    PubMed

    Zas, R; Sampedro, L

    2015-01-01

    Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent-offspring regression using several common garden tests established in contrasting environments to separate G, E and G × E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h(2)=0.55-0.74). SW showed no apparent G × E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW.

  9. Prenatal Exposure to Bisphenol A at Environmentally Relevant Doses Adversely Affects the Murine Female Reproductive Tract Later in Life

    PubMed Central

    Newbold, Retha R.; Jefferson, Wendy N.; Padilla-Banks, Elizabeth

    2009-01-01

    Background Exposure to endocrine-disrupting chemicals during critical developmental periods causes adverse consequences later in life; an example is prenatal exposure to the pharmaceutical diethylstilbestrol (DES). Bisphenol A (BPA), an environmental estrogen used in the synthesis of plastics, is of concern because its chemical structure resembles that of DES, and it is a “high-volume production” chemical with widespread human exposure. Objectives In this study we investigated whether prenatal BPA causes long-term adverse effects in female reproductive tissues in an experimental animal model previously shown useful in studying effects of prenatal DES. Methods Timed pregnant CD-1 mice were treated on days 9–16 of gestation with BPA (0.1, 1, 10, 100, or 1,000 μg/kg/day). After delivery, pups were held for 18 months; reproductive tissues were then evaluated. Results Ovarian cysts were significantly increased in the 1-μg/kg BPA group; ovarian cyst-adenomas were seen in the other three BPA-treated groups but not in corn-oil controls. We observed increased progressive proliferative lesions of the oviduct after BPA treatment, similar to those described in response to DES. Further, although not statistically different from the controls, prominent mesonephric (Wolffian) remnants and squamous metaplasia of the uterus, as well as vaginal adenosis, were present in BPA-treated mice, similar to lesions reported following DES treatment. More severe pathologies observed in some BPA-treated animals included atypical hyperplasia and stromal polyps of the uterus; sarcoma of the uterine cervix; and mammary adenocarcinoma. We did not observe these lesions in controls. Conclusions These data suggest that BPA causes long-term adverse reproductive and carcinogenic effects if exposure occurs during critical periods of differentiation. PMID:19590677

  10. Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects

    PubMed Central

    Zas, R; Sampedro, L

    2015-01-01

    Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent–offspring regression using several common garden tests established in contrasting environments to separate G, E and G × E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h2=0.55–0.74). SW showed no apparent G × E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW. PMID:25160045

  11. Relevance of F-Specific RNA Bacteriophages in Assessing Human Norovirus Risk in Shellfish and Environmental Waters

    PubMed Central

    Hartard, C.; Banas, S.; Loutreul, J.; Rincé, A.; Benoit, F.; Boudaud, N.

    2016-01-01

    ABSTRACT Human noroviruses (HuNoVs) are the main cause of shellfish-borne gastroenteritis outbreaks. In the absence of routine technical approaches allowing infectious particles to be detected, this viral pathogen is currently targeted by genome research, leading to difficult interpretations. In this study, we investigated the potential of F-specific RNA bacteriophages (FRNAPH) as fecal and viral contamination indicators in shellfish and water from a local harvesting area. FRNAPH were also used as microbial source tracking tools. Constraints imposed by detection limits are illustrated here by the detection of infectious FRNAPH in several samples in the absence of FRNAPH genomes. The opposite situation was also observed, likely explained by the persistence of the genomes being greater than infectivity. Similar considerations may be applied to HuNoVs, suggesting that HuNoV genome targeting is of limited relevance in assessing infectious risks. While FRNAPH did not provide any benefits compared to Escherichia coli as fecal pollution indicators in water, novel observations were made in shellfish: contrary to E. coli, a seasonal trend of infectious FRNAPH concentrations was observed. These concentrations were higher than those found in water, confirming bioaccumulation in shellfish. This study also underlines a relationship between the presence of HuNoV genomes and those of human-specific FRNAPH subgroup II (FRNAPH-II) in shellfish collected throughout Europe. Further research should be undertaken to evaluate FRNAPH potential as an indicator of the presence of infectious HuNoVs. To this end, shellfish involved in HuNoV-caused gastroenteritis outbreaks should be analyzed for the presence of infectious FRNAPH-II. IMPORTANCE This work provides new data about the use of F-specific RNA phages (FRNAPH) as a tool for evaluating fecal or viral contamination, especially in shellfish. In our case study, FRNAPH did not provide any benefits compared to E. coli as fecal pollution

  12. Utilizing platforms for the observation of chemical transformations to surface-bound noble metal nanoparticles in environmentally relevant conditions

    NASA Astrophysics Data System (ADS)

    Glover, Richard David

    Nanoparticles are increasingly incorporated into consumer products because of their unique, size-dependent properties. Although these properties are commercially appealing, data are lacking regarding the fate and reactivity of nanoparticles once incorporated into materials. This information gap prevents accurate assessment of hazards that these materials potentially present to consumers and the environment. To address this concern, new research is needed to investigate the reactivity and transformations of nanoparticles. This dissertation describes the use of an electron transparent characterization platform to observe nanoparticle transformations. Nanoparticles were tethered to the surface of an analysis platform, exposed to a variety of conditions, and evaluated for reactivity and response. The characterization of silver nanoparticles revealed the generation of new daughter nanoparticles on surfaces in ambient humid conditions. Our observations showed that the transport of material is highly dependent on relative humidity and that pH equilibria drives the deposition of new particles and degradation. We discovered, by applying these findings to macro-silver objects, that bulk silver generates new nanoparticles on surfaces. This illuminated the possibility of other, yet undiscovered, naturally occurring nanoparticles. In the second model system, 1.5 nm gold nanoparticles were tethered by a robust metal oxide bond from the terminal group of the stabilizing ligand. This strategy facilitated precise control over thiol ligand removal using a dilute ozone oxidation. Tracking particle oxidation over time allowed us to gain unprecedented control over core exposure, size maintenance, and surface tethering. This platform was also utilized as a proof-of-concept for direct observation of transformations in complex media. Ligand and core transformations were monitored in a variety of biologically relevant conditions using tethered nanoparticles. Morphological and chemical

  13. Influence of environmentally relevant concentrations of vinclozolin on quality, DNA integrity, and antioxidant responses of sterlet Acipenser ruthenus spermatozoa.

    PubMed

    Gazo, Ievgeniia; Linhartova, Pavla; Shaliutina, Anna; Hulak, Martin

    2013-04-25

    The effects of vinclozolin (VIN), an anti-androgenic fungicide, on quality, oxidative stress, DNA integrity, and ATP level of sterlet (Acipenser ruthenus) spermatozoa were investigated in vitro. Fish spermatozoa were incubated with different concentrations of vinclozolin (0.5, 2, 10, 15, 20 and 50 μg/l) for 2 h. A dose-dependent reduction in spermatozoa motility and velocity was observed at concentrations of 2-50 μg/l. A dramatic increase in DNA fragmentation was recorded at concentrations 10 μg/l and above. After 2 h exposure at higher test concentrations (10-50 μg/l), oxidative stress was apparent, as reflected by significantly higher levels of protein and lipid oxidation and significantly greater superoxide dismutase activity. Intracellular ATP content of spermatozoa decreased with increasing concentrations of VIN. The results demonstrated that VIN can induce reactive oxygen species stress in fish spermatozoa, which could impair the sperm quality, DNA integrity, ATP content, and the antioxidant defense system. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Quantitative PCR assays to survey the bovine adenovirus levels in environmental samples.

    PubMed

    Wong, K; Xagoraraki, I

    2010-08-01

    Previous studies suggested bovine adenoviruses (BAdVs) could be used as cattle faecal indicators. The main aim of this study was to survey the levels of BAdV in environmental samples using quantitative polymerase chain reaction (qPCR). Two qPCR assays were developed to identify and quantify BAdVs in environmental samples. BAdVs were detected in all dairy manure, and in most cases, the sample concentrations were around 10(3)-10(4) copies ml(-1). Farm tile drainage samples were also detected, but the concentrations were about 1-3 log(10) lower than the BAdV concentrations in the manure samples. The genome equivalent copy (GEC) levels of BAdV and the phage forming unit (PFU) levels of somatic phage in manure samples were comparable. Four of twenty individual cattle faeces were positive with concentrations similar to that found in the manure samples. Sequencing results confirmed the presence of BAdV in the environmental samples, and phylogenetic analysis indicated that BAdV 2 and 4 were the most prevalent serotypes in all the manure samples tested. The qPCR assays developed in this study showed higher sensitivity in detecting BAdV 1 and 2 than the previous published nested assay. The high levels of BAdV in the environmental samples may suggest it could be used for bovine faecal indicator. The significant levels of BAdV in the drainage samples may indicate the potential of surface water pollution by the manure applied to farm fields. This is the first study that reports the quantitative level of BAdV in environmental samples. These results could be useful when it comes to determining whether BAdV could be utilized as a bovine faecal indicator.

  15. Circulating levels of environmental contaminants are associated with dietary patterns in older adults.

    PubMed

    Ax, Erika; Lampa, Erik; Lind, Lars; Salihovic, Samira; van Bavel, Bert; Cederholm, Tommy; Sjögren, Per; Lind, P Monica

    2015-02-01

    Food intake contributes substantially to our exposure to environmental contaminants. Still, little is known about our dietary habits' contribution to exposure variability. The aim of this study was to assess circulating levels of environmental contaminants in relation to predefined dietary patterns in an elderly Swedish population. Dietary data and serum concentrations of environmental contaminants were obtained from 844 70-year-old Swedish subjects (50% women) in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Dietary data from 7-day food records was used to assess adherence to a Mediterranean-like diet, a low carbohydrate-high protein diet and the WHO dietary recommendations. Circulating levels of 6 polychlorinated biphenyl markers, 3 organochlorine pesticides, 1 dioxin and 1 polybrominated diphenyl ether, the metals cadmium, lead, mercury and aluminum and serum levels of bisphenol A and 4 phthalate metabolites were investigated in relation to dietary patterns in multivariate linear regression models. A Mediterranean-like diet was positively associated with levels of several polychlorinated biphenyls (118, 126, 153, and 209), trans-nonachlor and mercury. A low carbohydrate-high protein diet was positively associated with polychlorinated biphenyls 118 and 153, trans-nonachlor, hexachlorobenzene and p, p'-dichlorodiphenyldichloroethylene, mercury and lead. The WHO recommended diet was negatively related to levels of dioxin and lead, and borderline positively to polychlorinated biphenyl 118 and trans-nonachlor. Dietary patterns were associated in diverse manners with circulating levels of environmental contaminants in this elderly Swedish population. Following the WHO dietary recommendations seems to be associated with a lower burden of environmental contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Environmentally relevant concentrations of galaxolide (HHCB) and tonalide (AHTN) induced oxidative and genetic damage in Dreissena polymorpha.

    PubMed

    Parolini, Marco; Magni, Stefano; Traversi, Irene; Villa, Sara; Finizio, Antonio; Binelli, Andrea

    2015-03-21

    Synthetic musk compounds (SMCs) are extensively used as fragrances in several personal care products and have been recognized as emerging aquatic pollutants. Among SMCs, galaxolide (HHCB) and tonalide (AHTN) are extensively used and have been measured in aquatic ecosystems worldwide. However, their potential risk to organisms remains largely unknown. The aim of this study was to investigate whether 21-day exposures to HHCB and AHTN concentrations frequently measured in aquatic ecosystems can induce oxidative and genetic damage in Dreissena polymorpha. The lipid peroxidation (LPO) and protein carbonyl content (PCC) were measured as oxidative stress indexes, while the DNA precipitation assay and the micronucleus test (MN test) were applied to investigate genetic injuries. HHCB induced significant increases in LPO and PCC levels, while AHTN enhanced only protein carbonylation. Moreover, significant increases in DNA strand breaks were caused by exposure to the highest concentrations of HHCB and AHTN tested in the present study, but no fixed genetic damage was observed.

  17. Lifestyle/environmental factors and blood cadmium levels in hypertensive and normotensive individuals.

    PubMed

    Fontana, S A; Boulos, B M

    1986-12-01

    Cadmium is a non-essential trace metal presently found at environmental concentration far exceeding its natural occurrence, to which human populations are exposed form diverse sources. Animals exposed chronically to subtoxic cadmium levels develop hypertension, yet human studies are inconclusive. In the present study, the relationship between lifestyle/environment factors and blood cadmium levels was investigated. Black females aged 50-75 years were chosen from university clinics and community settings (30 normotensives and 32 hypertensives). Questionnaires giving environmental, lifestyle and other date were collected. Cadmium blood levels were determined by atomic absorption spectophotometry; and results indicated a high degree of precision and accuracy for the cadmium analytical technique which was used. No significant differences were found in cadmium blood levels between groups.

  18. An Environmental Chemistry Experiment: The Determination of Radon Levels in Water.

    ERIC Educational Resources Information Center

    Welch, Lawrence E.; Mossman, Daniel M.

    1994-01-01

    Describes a radiation experiment developed to complement a new environmental chemistry laboratory curriculum. A scintillation counter is used to measure radon in water. The procedure relies on the fact that toluene will preferentially extract radon from water. Sample preparation is complete in less than 90 minutes. Because the level of…

  19. Can Eco-Schools Improve Elementary School Students' Environmental Literacy Levels?

    ERIC Educational Resources Information Center

    Ozsoy, Sibel; Ertepinar, Hamide; Saglam, Necdet

    2012-01-01

    This study was conducted to investigate the effects of eco-schools on elementary school students' environmental literacy levels. Data of the study were gathered from 316 students enrolled to two elementary schools. One of the schools was determined as experimental group (n = 156) and students attending this school received eco-school application.…

  20. Can Eco-Schools Improve Elementary School Students' Environmental Literacy Levels?

    ERIC Educational Resources Information Center

    Ozsoy, Sibel; Ertepinar, Hamide; Saglam, Necdet

    2012-01-01

    This study was conducted to investigate the effects of eco-schools on elementary school students' environmental literacy levels. Data of the study were gathered from 316 students enrolled to two elementary schools. One of the schools was determined as experimental group (n = 156) and students attending this school received eco-school application.…

  1. Validating Performance Level Descriptors (PLDs) for the AP® Environmental Science Exam

    ERIC Educational Resources Information Center

    Reshetar, Rosemary; Kaliski, Pamela; Chajewski, Michael; Lionberger, Karen

    2012-01-01

    This presentation summarizes a pilot study conducted after the May 2011 administration of the AP Environmental Science Exam. The study used analytical methods based on scaled anchoring as input to a Performance Level Descriptor validation process that solicited systematic input from subject matter experts.

  2. Probing the Natural World, Level III, Student Guide: Environmental Science. Intermediate Science Curriculum Study.

    ERIC Educational Resources Information Center

    Bonar, John R., Ed.; Hathway, James A., Ed.

    This is the student's edition of one of the Intermediate Science Curriculum Study (ISCS) units for level III students (grade 9). The chapters contain basic information about environmental pollution and hazards, activities related to the subject, and optional excursions. A section on introductory notes to the student discusses how to use the book…

  3. Probing the Natural World, Level III, Teacher's Edition: Environmental Science. Intermediate Science Curriculum Study.

    ERIC Educational Resources Information Center

    Bonar, John R., Ed.; Hathway, James A., Ed.

    This is the teacher's edition of one of the eight units of the Intermediate Science Curriculum Study (ISCS) for level III students (grade 9). This unit and its activities focuses on environmental pollution and hazards. Optional excursions are suggested for students who wish to study an area in greater depth. An introduction describes the problem…

  4. An Environmental Chemistry Experiment: The Determination of Radon Levels in Water.

    ERIC Educational Resources Information Center

    Welch, Lawrence E.; Mossman, Daniel M.

    1994-01-01

    Describes a radiation experiment developed to complement a new environmental chemistry laboratory curriculum. A scintillation counter is used to measure radon in water. The procedure relies on the fact that toluene will preferentially extract radon from water. Sample preparation is complete in less than 90 minutes. Because the level of…

  5. Nature of Environmental Education in Bangladesh: A School Level Assessment with Reference to the National Curriculum

    ERIC Educational Resources Information Center

    Chowdhury, M. A. Taiyeb

    2014-01-01

    This paper attempts to identify the nature of formal environmental education in Bangladesh at school level with particular reference to the national curriculum. The main objective of the study is to assess the contents of the school textbooks for each standard, and to see whether the diversified themes covered are a good representation of…

  6. Differential sensitivities of bone marrow, spleen and thymus to genotoxicity induced by environmentally relevant concentrations of arsenite.

    PubMed

    Xu, Huan; McClain, Shea; Medina, Sebastian; Lauer, Fredine T; Douillet, Christelle; Liu, Ke Jian; Hudson, Laurie G; Stýblo, Miroslav; Burchiel, Scott W

    2016-11-16

    It is known in humans and mouse models, that drinking water exposures to arsenite (As(+3)) leads to immunotoxicity. Previously, our group showed that certain types of immune cells are extremely sensitive to arsenic induced genotoxicity. In order to see if cells from different immune organs have differential sensitivities to As(+3), and if the sensitivities correlate with the intracellular concentrations of arsenic species, male C57BL/6J mice were dosed with 0, 100 and 500ppb As(+3)via drinking water for 30d. Oxidation State Specific Hydride Generation- Cryotrapping- Inductively Coupled Plasma- Mass Spectrometry (HG- CT- ICP- MS) was applied to analyze the intracellular arsenic species and concentrations in bone marrow, spleen and thymus cells isolated from the exposed mice. A dose-dependent increase in intracellular monomethylarsonous acid (MMA(+3)) was observed in both bone marrow and thymus cells, but not spleen cells. The total arsenic and MMA(+3) levels were correlated with an increase in DNA damage in bone marrow and thymus cells. An in vitro treatment of 5, 50 and 500nM As(+3) and MMA(+3) revealed that bone marrow cells are most sensitive to As(+3) treatment, and MMA(+3) is more genotoxic than As(+3). These results suggest that the differential sensitivities of the three immune organs to As(+3) exposure are due to the different intracellular arsenic species and concentrations, and that MMA(+3) may play a critical role in immunotoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Environmentally relevant concentrations of ammonium perchlorate inhibit thyroid function and alter sex ratios in developing Xenopus laevis.

    PubMed

    Goleman, Wanda L; Carr, James A; Anderson, Todd A

    2002-03-01

    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.

  8. Response of phytochelatins and their relationship with cadmium toxicity in a floating macrophyte Pistia stratiotes L. at environmentally relevant concentrations.

    PubMed

    Wang, C; Wang, L Y; Sun, Q

    2010-02-01

    An indoor experiment was undertaken to investigate the response of phytochelatins and their relationship to cadmium toxicity in Pistia stratiotes L., a free-floating macrophyte, exposed to low concentrations of cadmium typically found in realistic environments. Cadmium concentrations of 0.01 to 0.08 microM had no toxic effects on the growth of this plant, as indicated by no significant changes in the fresh weights of leaves and roots and the slight induction of phytochelatins in plant tissues, whereas cadmium concentrations of 0.16 to 1 microM were toxic, and cadmium toxicity increased with the increase of cadmium concentrations in solutions, accompanied by the dramatic production of phytochelatins in plant tissues, especially in roots. There was a positive correction between root phytochelatin levels and cadmium toxicity, as measured by the growth inhibition rate of the root fresh weight. The results suggested that phytochelatins in aquatic macrophytes can serve as sensitive biomarkers for heavy metal toxicity in a moderately polluted water environment.

  9. p,p′-DDE activates CatSper and compromises human sperm function at environmentally relevant concentrations

    PubMed Central

    Tavares, Renata S.; Mansell, Steven; Barratt, Christopher L.R.; Wilson, Stuart M.; Publicover, Stephen J.; Ramalho-Santos, João

    2013-01-01

    STUDY QUESTION Is the environmental endocrine disruptor p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) able to induce non-genomic changes in human sperm and consequently affect functional sperm parameters? SUMMARY ANSWER p,p′-DDE promoted Ca2+ flux into human sperm by activating CatSper channels even at doses found in human reproductive fluids, ultimately compromising sperm parameters important for fertilization. WHAT IS KNOWN ALREADY p,p′-DDE may promote non-genomic actions and interact directly with pre-existing signaling pathways, as already observed in other cell types. However, although often found in both male and female reproductive fluids, its effects on human spermatozoa function are not known. STUDY DESIGN, SIZE, DURATION Normozoospermic sperm samples from healthy individuals were included in this study. Samples were exposed to several p,p′-DDE concentrations for 3 days at 37°C and 5% CO2 in vitro to mimic the putative continuous exposure to this toxicant in the female reproductive tract in vivo. Shorter p,p′-DDE incubation periods were also performed in order to monitor sperm rapid Ca2+ responses. All experiments were repeated on a minimum of five sperm samples from different individuals. PARTICIPANTS/MATERIALS, SETTING, METHODS All healthy individuals were recruited at the Biosciences School, University of Birmingham, the Medical Research Institute, University of Dundee and in the Human Reproduction Service at University Hospitals of Coimbra. Intracellular Ca2+ concentration ([Ca2+]i) was monitored by imaging single spermatozoa loaded with Oregon Green BAPTA-1AM and further whole-cell patch-clamp recordings were performed to validate our results. Sperm viability and acrosomal integrity were assessed using the LIVE/DEAD sperm vitality kit and the acrosomal content marker PSA-FITC, respectively. MAIN RESULTS AND THE ROLE OF CHANCE p,p′-DDE rapidly increased [Ca2+]i (P < 0.05) even at extremely low doses (1 pM and 1 nM), with magnitudes of

  10. The effects of antibiotic cocktails at environmentally relevant concentrations on the community composition and acetate biodegradation kinetics of bacterial biofilms.

    PubMed

    Wunder, David B; Tan, David T; LaPara, Timothy M; Hozalski, Raymond M

    2013-02-01

    Antibiotics and antibacterials are present in water bodies worldwide but little is known about their effects on the biological processes often used to treat water. In this research, the effect of antibiotics on bacterial activity and community structure was investigated by growing biofilms in the presence and absence of a mixture of three compounds (sulfamethoxazole, erythromycin, and ciprofloxacin) in a continuous-flow rotating annular bioreactor fed acetate as a carbon and energy source. Steady-state, surface area-normalized substrate utilization rates for all antibiotic treatments (all at 0.33 μg L(-1), all at 3.33 μg L(-1), and 1 at 3.33 μg L(-1) with the other 2 at 0.33 μg L(-1)) were similar to the control experiments. Higher attached biomass levels in the experiments with ciprofloxacin at 3.33 μg L(-1) resulted in lower steady-state biomass-normalized substrate utilization rates in comparison to other runs. Microbial community analyses via automated ribosomal intergenic spacer analysis revealed significant shifts in community structure for the experiments dosed with the highest concentrations of ciprofloxacin, suggesting that the antibiotic selected for more resistant bacterial strains. The results of this research also suggest that mixtures of antibiotics at the sub-μg L(-1) concentrations typically observed in surface waters are unlikely to affect biological process performance, at least in terms of the degradation of easily assimilable compounds. Conversely, changes to community structure and biofilm quantity might be expected with ciprofloxacin at μg L(-1) concentrations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Short and long term bystander effect induction by fathead minnows (Pimephales promelas, Rafinesque, 1820) injected with environmentally relevant whole body doses of 226Ra.

    PubMed

    Smith, Richard W; Seymour, Colin B; Mothersill, Carmel E

    2013-12-01

    Bystander effect induction by fathead minnows injected with environmentally relevant doses of (226)Ra was investigated. Twenty four h and 6 months after injection with a single dose of 21, 210 or 2100 μBq, fin tissue samples emitted a pro-apoptotic signal, which reduced the clonogenic survival of an apoptosis sensitive reporter cell line. Twenty four h and 10 weeks after injection explants from non-injected bystander fish, swum with the injected fish, also emitted a pro-apoptotic signal. However 6 months after injection the bystander fish to 21 and 210 μBq injected fish emitted an anti-apoptotic signal. This demonstrates that extremely low dose irradiation can have effects outside of the irradiated fish. This has implications for population and ecosystem responses to contamination. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Maternal exposure to an environmentally relevant dose of triclocarban results in perinatal exposure and potential alterations in offspring development in the mouse model.

    PubMed

    Enright, Heather A; Falso, Miranda J S; Malfatti, Michael A; Lao, Victoria; Kuhn, Edward A; Hum, Nicholas; Shi, Yilan; Sales, Ana Paula; Haack, Kurt W; Kulp, Kristen S; Buchholz, Bruce A; Loots, Gabriela G; Bench, Graham; Turteltaub, Kenneth W

    2017-01-01

    Triclocarban (TCC) is among the top 10 most commonly detected wastewater contaminants in both concentration and frequency. Its presence in water, as well as its propensity to bioaccumulate, has raised numerous questions about potential endocrine and developmental effects. Here, we investigated whether exposure to an environmentally relevant concentration of TCC could result in transfer from mother to offspring in CD-1 mice during gestation and lactation using accelerator mass spectrometry (AMS). 14C-TCC (100 nM) was administered to dams through drinking water up to gestation day 18, or from birth to post-natal day 10. AMS was used to quantify 14C-concentrations in offspring and dams after exposure. We demonstrated that TCC does effectively transfer from mother to offspring, both trans-placentally and via lactation. TCC-related compounds were detected in the tissues of offspring with significantly higher concentrations in the brain, heart and fat. In addition to transfer from mother to offspring, exposed offspring were heavier in weight than unexposed controls demonstrating an 11% and 8.5% increase in body weight for females and males, respectively. Quantitative real-time polymerase chain reaction (qPCR) was used to examine changes in gene expression in liver and adipose tissue in exposed offspring. qPCR suggested alterations in genes involved in lipid metabolism in exposed female offspring, which was consistent with the observed increased fat pad weights and hepatic triglycerides. This study represents the first report to quantify the transfer of an environmentally relevant concentration of TCC from mother to offspring in the mouse model and evaluate bio-distribution after exposure using AMS. Our findings suggest that early-life exposure to TCC may interfere with lipid metabolism and could have implications for human health.

  13. Maternal exposure to an environmentally relevant dose of triclocarban results in perinatal exposure and potential alterations in offspring development in the mouse model

    DOE PAGES

    Enright, Heather A.; Falso, Miranda J. S.; Malfatti, Michael A.; ...

    2017-08-09

    Triclocarban (TCC) is among the top 10 most commonly detected wastewater contaminants in both concentration and frequency. Its presence in water, as well as its propensity to bioaccumulate, has raised numerous questions about potential endocrine and developmental effects. Here in this paper, we investigated whether exposure to an environmentally relevant concentration of TCC could result in transfer from mother to offspring in CD-1 mice during gestation and lactation using accelerator mass spectrometry (AMS). 14C-TCC (100 nM) was administered to dams through drinking water up to gestation day 18, or from birth to post-natal day 10. AMS was used to quantifymore » 14C-concentrations in offspring and dams after exposure. We demonstrated that TCC does effectively transfer from mother to offspring, both trans-placentally and via lactation. TCC-related compounds were detected in the tissues of offspring with significantly higher concentrations in the brain, heart and fat. In addition to transfer from mother to offspring, exposed offspring were heavier in weight than unexposed controls demonstrating an 11% and 8.5% increase in body weight for females and males, respectively. Quantitative real-time polymerase chain reaction (qPCR) was used to examine changes in gene expression in liver and adipose tissue in exposed offspring. qPCR suggested alterations in genes involved in lipid metabolism in exposed female offspring, which was consistent with the observed increased fat pad weights and hepatic triglycerides. This study represents the first report to quantify the transfer of an environmentally relevant concentration of TCC from mother to offspring in the mouse model and evaluate bio-distribution after exposure using AMS. Our findings suggest that early-life exposure to TCC may interfere with lipid metabolism and could have implications for human health.« less

  14. Vulnerability-Based Spatial Sampling Stratification for the National Children’s Study, Worcester County, Massachusetts: Capturing Health-Relevant Environmental and Sociodemographic Variability

    PubMed Central

    Downs, Timothy J.; Ogneva-Himmelberger, Yelena; Aupont, Onesky; Wang, Yangyang; Raj, Ann; Zimmerman, Paula; Goble, Robert; Taylor, Octavia; Churchill, Linda; Lemay, Celeste; McLaughlin, Thomas; Felice, Marianne

    2010-01-01

    Background The National Children’s Study is the most ambitious study ever attempted in the United States to assess how environmental factors impact child health and development. It aims to follow 100,000 children from gestation until 21 years of age. Success requires breaking new interdisciplinary ground, starting with how to select the sample of > 1,000 children in each of 105 study sites; no standardized protocol exists for stratification of the target population by factoring in the diverse environments it inhabits. Worcester County, Massachusetts, like other sites, stratifies according to local conditions and local knowledge, subject to probability sampling rules. Objectives We answer the following questions: How do we divide Worcester County into viable strata that represent its health-relevant environmental and sociodemographic heterogeneity, subject to sampling rules? What potential does our approach have to inform stratification at other sites? Results We developed a multivariable, vulnerability-based method for spatial sampling consisting of two descriptive indices: a hazards/stressors exposure index (comprising three proxy variables), and an adaptive capacity/sociodemographic character index (five variables). Multivariable, health-relevant stratification at the start of the study may improve detection power for environment–child health associations down the line. Eighteen strata capture countywide heterogeneity in the indices and have optimal relative homogeneity within each. They achieve comparable expected birth counts and conform to local concepts of space. Conclusion The approach offers moderate to high potential to inform other sites, limited by intersite differences in data availability, geodemographics, and technical capacity. Energetic community engagement from the start promotes local stratification coherence, plus vital researcher–community trust and co-ownership for sustainability. PMID:20211802

  15. Effects of chronic exposure to environmentally relevant concentrations of waterborne depleted uranium on the digestive tract of zebrafish, Danio rerio.

    PubMed

    Augustine, Starrlight; Pereira, Sandrine; Floriani, Magali; Camilleri, Virginie; Kooijman, Sebastiaan A L M; Gagnaire, Béatrice; Adam-Guillermin, Christelle

    2015-04-01

    Uranium is a naturally occurring element, but activities linked to the nuclear fuel cycle can increase background levels in the surrounding waters. For this reason it is important to understand how this affects organisms residing in the water column. The objective of this study was to assess histopathological effects of uranium on the gut wall of a widely used model organism: zebrafish, Danio rerio. To this end we exposed zebrafish to 84 and 420 nM depleted uranium for over a month and then examined the histology of intestines of exposed individuals compared to controls. The gut wall of individuals exposed to 84 and 420 nM of uranium had large regions of degraded mucosa. Using transmission electron microscopy (TEM) coupled to energy-dispersive X-ray spectroscopy microanalysis (EDX) we found that uranium induced a decrease in the amount of calcium containing mitochondrial matrix granules per mitochondria. This is suggestive of perturbations to cellular metabolism and more specifically to cellular calcium homeostasis. TEM-EDX of the gut wall tissue further showed that some uranium was internalized in the nucleus of epithelial cells in the 420 nM treatment. Fluorescent in situ hybridization using specific probes to detect all eubacteria was performed on frozen sections of 6 individual fish in the 84 nM and 420 nM treatments. Bacterial colonization of the gut of individuals in the 420 nM seemed to differ from that of the controls and 84 nM individuals. We suggest that host-microbiota interactions are potentially disturbed in response to uranium induced stress. The damage induced by waterborne uranium to the gut wall did not seem to depend on the concentration of uranium in the media. We measure whole body residues of uranium at the end of the experiment and compute the mean dose rate absorbed for each condition. We discuss why effects might be uncoupled from external concentration and highlight that it is not so much the external concentration but the dynamics of

  16. Australia’s first national level quantitative environmental justice assessment of industrial air pollution

    NASA Astrophysics Data System (ADS)

    Chakraborty, Jayajit; Green, Donna

    2014-04-01

    This study presents the first national level quantitative environmental justice assessment of industrial air pollution in Australia. Specifically, our analysis links the spatial distribution of sites and emissions associated with industrial pollution sources derived from the National Pollution Inventory, to Indigenous status and social disadvantage characteristics of communities derived from Australian Bureau of Statistics indicators. Our results reveal a clear national pattern of environmental injustice based on the locations of industrial pollution sources, as well as volume, and toxicity of air pollution released at these locations. Communities with the highest number of polluting sites, emission volume, and toxicity-weighted air emissions indicate significantly greater proportions of Indigenous population and higher levels of socio-economic disadvantage. The quantities and toxicities of industrial air pollution are particularly higher in communities with the lowest levels of educational attainment and occupational status. These findings emphasize the need for more detailed analysis in specific regions and communities where socially disadvantaged groups are disproportionately impacted by industrial air pollution. Our empirical findings also underscore the growing necessity to incorporate environmental justice considerations in environmental planning and policy-making in Australia.

  17. Momentum sequence and environmental climate influence levels of perceived psychological momentum within a sport competition.

    PubMed

    Briki, Walid; Markman, Keith D; Coudevylle, Guillaume; Sinnapah, Stéphane; Hue, Olivier

    2016-01-01

    The present study examined the influence of momentum sequence (positive vs. negative) and environmental climate (hot-wet vs. neutral) on supporters' (i.e. virtual observers') reported levels of perceived psychological momentum (PM) during a simulated cycling competition. Participants supported one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall. The race scenario was manipulated so that the supported cyclist appeared to undergo either a positive or negative momentum sequence. In addition, participants were either exposed to a hot-wet environmental climate or to a neutral environmental climate while observing the race scenario. According to the results, reported levels of PM were higher in the positive momentum sequence condition than in the negative momentum sequence condition, consistent with the notion that supporters' PM is influenced by a positivity bias, and reported levels of PM were also found to be higher in the hot-wet climate condition than in the neutral climate condition, consistent with the notion that environmental climate is a contextual factor that influences PM through the operation of a causal augmenting mechanism.

  18. Impact of Individual-, Environmental-, and Policy-Level Factors on Health Care Utilization Among US Farmworkers

    PubMed Central

    Mayer, Joni A.; Gabbard, Susan; Kronick, Richard G.; Roesch, Scott C.; Malcarne, Vanessa L.; Zuniga, Maria L.

    2011-01-01

    Objectives. We examined individual-, environmental-, and policy-level correlates of US farmworker health care utilization, guided by the behavioral model for vulnerable populations and the ecological model. Methods. The 2006 and 2007 administrations of the National Agricultural Workers Survey (n = 2884) provided the primary data. Geographic information systems, the 2005 Uniform Data System, and rurality and border proximity indices provided environmental variables. To identify factors associated with health care use, we performed logistic regression using weighted hierarchical linear modeling. Results. Approximately half (55.3%) of farmworkers utilized US health care in the previous 2 years. Several factors were independently associated with use at the individual level (gender, immigration and migrant status, English proficiency, transportation access, health status, and non-US health care utilization), the environmental level (proximity to US–Mexico border), and the policy level (insurance status and workplace payment structure). County Federally Qualified Health Center resources were not independently associated. Conclusions. We identified farmworkers at greatest risk for poor access. We made recommendations for change to farmworker health care access at all 3 levels of influence, emphasizing Federally Qualified Health Center service delivery. PMID:21330594

  19. Low-level waste management alternatives and analysis in DOE`s programmatic environmental impact statement

    SciTech Connect

    Gerstein, J.S.

    1993-03-01

    The Department of Energy is preparing a Programmatic Environmental Impact Statement (PEIS) for the Environmental Restoration and Waste Management Program. The PEIS has been divided into an Environmental Restoration section and a Waste Management section. Each section has a unique set of alternatives. This paper will focus on the waste management alternatives and analysis. The set of alternatives for waste management has been divided into waste categories. These categories are: high-level waste, transuranic waste, low-level waste, low-level mixed waste, greater-than-class C and low-level waste from commercial sources, hazardous waste, and spent nuclear fuel. This paper will discuss the alternatives and analytical approach that will be used to evaluate these alternatives for the low-level waste section. Although the same alternatives will be considered for all waste types, the analysis will be performed separately for each waste type. In the sections that follow, information will be provided on waste management configurations, the analysis of waste management alternatives, waste types and locations, facility and transportation activities, the facility and transportation impacts assessment, and the compilation of impacts.

  20. Ecological performance of red drum (Sciaenops ocellatus) larvae exposed to environmental levels of the insecticide malathion.

    PubMed

    Del Carmen Alvarez, Maria; Fuiman, Lee A

    2006-05-01

    Malathion is a highly soluble organophosphate insecticide that is widely used in agriculture and mosquito eradication campaigns. Fish species, such as red drum (Sciaenops ocellatus), that use seagrass beds as nursery areas could be affected by runoff waters contaminated with malathion. We exposed red drum larvae at the size they reach in estuarine nursery areas to environmentally realistic and sublethal levels of malathion (0, 1, and 10 microg/L). We evaluated the effects of such exposure on ecologically significant behaviors (routine swimming and predator evasion), growth, and resting metabolism. Malathion exposure to relatively low but ecologically realistic concentrations did not affect routine behavior, escape behavior, resting metabolic rate, or growth, indicating that reported environmental levels may be safe for young fishes. However, a recent substantial increase in the use of malathion may elevate surface-water concentrations to levels above those tested in the present study.

  1. Relevance of Education and Intelligence at the National Level for Health: The Case of HIV and AIDS

    ERIC Educational Resources Information Center

    Rindermann, Heiner; Meisenberg, Gerhard

    2009-01-01

    Studies at the individual level have shown a negative effect of education and intelligence on risky behavior. The same has been demonstrated for risky sexual behavior and for HIV-infection rates in sub-Saharan Africa. In path analyses at the country data level, cognitive abilities (seen as depending on education) show a strong negative effect on…

  2. Relevance of Education and Intelligence at the National Level for Health: The Case of HIV and AIDS

    ERIC Educational Resources Information Center

    Rindermann, Heiner; Meisenberg, Gerhard

    2009-01-01

    Studies at the individual level have shown a negative effect of education and intelligence on risky behavior. The same has been demonstrated for risky sexual behavior and for HIV-infection rates in sub-Saharan Africa. In path analyses at the country data level, cognitive abilities (seen as depending on education) show a strong negative effect on…

  3. Environmental Assessment Idaho National Engineering Laboratory, low-level and mixed waste processing

    SciTech Connect

    Not Available

    1994-06-01

    The Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0843, for the Idaho National Engineering Laboratory (INEL) low-level and mixed waste processing. The original proposed action, as reviewed in this EA, was (1) to incinerate INEL`s mixed low-level waste (MLLW) at the Waste Experimental Reduction Facility (WERF); (2) reduce the volume of INEL generated low-level waste (LLW) through sizing, compaction, and stabilization at the WERF; and (3) to ship INEL LLW to a commercial incinerator for supplemental LLW volume reduction.

  4. Rapid Identification of Clinically Relevant Nocardia Species to Genus Level by 16S rRNA Gene PCR

    PubMed Central

    Laurent, Frederic J.; Provost, Frederique; Boiron, Patrick

    1999-01-01

    Two regions of the gene coding for 16S rRNA in Nocardia species were selected as genus-specific primer sequences for a PCR assay. The PCR protocol was tested with 60 strains of clinically relevant Nocardia isolates and type strains. It gave positive results for all strains tested. Conversely, the PCR assay was negative for all tested species belonging to the most closely related genera, including Dietzia, Gordona, Mycobacterium, Rhodococcus, Streptomyces, and Tsukamurella. Besides, unlike the latter group of isolates, all Nocardia strains exhibited one MlnI recognition site but no SacI restriction site. This assay offers a specific and rapid alternative to chemotaxonomic methods for the identification of Nocardia spp. isolated from pathogenic samples. PMID:9854071

  5. Detection and Quantification of Silver Nanoparticles at Environmentally Relevant Concentrations Using Asymmetric Flow Field??Flow Fractionation Online with Single Particle Inductively Coupled Plasma Mass Spectrometry

    EPA Pesticide Factsheets

    The presence of silver nanoparticles (AgNPs) in aquatic environments could potentially cause adverse impacts on ecosystems and human health. However, current understanding of the environmental fate and transport of AgNPs is still limited because their properties in complex environmental samples cannot be accurately determined. In this study, the feasibility of using asymmetric flow field-flow fractionation (AF4) connected online with single particle inductively coupled plasma mass spectrometry (spICPMS) to detect and quantify AgNPs at environmentally relevant concentrations was investigated. The AF4 channel had a thickness of 350 00b5m and its accumulation wall was a 10 kDa regenerated cellulose membrane. A 0.02 % FL-70 surfactant solution was used as an AF4 carrier. With 1.2 mL/min AF4 cross flow rate, 1.5 mL/min AF4 channel flow rate, and 5 ms spICPMS dwell time, the AF4??spICPMS can detect and quantify 40 ?? 80 nm AgNPs, as well as Ag-SiO2 nanoparticles (51.0 nm diameter Ag core and 21.6 nm SiO2 shell), with good recovery within 30 min. This system was not only effective in differentiating and quantifying different types of AgNPs with similar hydrodynamic diameters, such as in mixtures containing Ag-SiO2 core-shell nanoparticles and 40 ?? 80 nm AgNPs, but also suitable for differentiating between 40 nm AgNPs and elevated dissolved Ag content. The study results indicate that AF4??spICPMS is capable of detecting and quantifying AgNPs and other engineered

  6. The Association between Exposure to Environmental Bisphenol A and Gonadotropic Hormone Levels among Men

    PubMed Central

    Chen, Jianping; Shi, Huijuan; Zhu, Jiang; Liu, Xiaoqin; Wang, Jian; Miao, Maohua; Yuan, Wei

    2017-01-01

    Bisphenol A (BPA) is an extensively used chemical with endocrine disrupting properties. Although animal and in vivo studies have suggested possible effects of BPA on levels of gonadotropic hormones, human studies are limited and inconclusive. The study examined whether environmental BPA exposure was associated with gonadotropic hormones levels in men. A total of 560 men aged 18–55 years were recruited from Sandu County, Guizhou Province, China. We collected urine samples for measurement of BPA, and blood samples for measurement of reproductive hormones. We examined serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone (T). Relative risk (RR) was obtained by log-binominal regression to explore the association between urinary BPA level and hormone levels. BPA was detected in 70.4% of urine samples, with a geometric mean of 0.50 μg/gCr. Men with detectable levels of BPA had a 1.52-fold increased risk of having a high LH level (>75th percentile) when compared with men with undetectable levels of BPA, after adjustment for potential confounders (95% confidence interval (CI): 1.04–2.21). The association persisted and slightly intensified among current smokers (adjusted RR (aRR) = 1.76, 95%CI: 1.05–2.95), while it weakened among non-smokers (aRR = 1.17, 95%CI: 0.69–1.96). Urinary BPA level was associated with an increased FSH level among smokers (aRR = 1.64, 95%CI: 1.01–2.67). Urinary BPA level was inversely associated with total T level among males with body max index (BMI) ≥25 kg/m2 although this association was of borderline significance (aRR = 0.52, 95%CI: 0.26–1.05). In conclusion, environmental exposure to BPA was associated with increased serum levels of LH and FSH in male smokers, along with decreased serum levels of total T in men with BMI≥25 kg/m2. These findings suggest that the effects of environmental BPA exposure on hormone levels might be modified by smoking and BMI. PMID:28085949

  7. Geoecology: a county-level environmental data base for the conterminous United States

    SciTech Connect

    Olson, R.J.; Emerson, C.J.; Nungesser, M.K.

    1980-09-01

    The Geoecology Data Base represents a unique compilation of computerized environmental data for research and development needs. Environmental assessment and planning for energy development require rapid access to data at appropriate spatial and temporal scales. In the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL), we have developed an integrated data base of diverse environmental resource information from extant sources. Data are stored at the county level of resolution for the conterminous United States with some data available for subcounty units within larger, more diverse eastern counties. The Geoecology Data Base contains selected data on terrain and soils, water resources, forestry, vegetation, agriculture, land use, wildlife, air quality, climate, natural areas, and endangered species. Basic files on human population are also included to complement the environmental files. Data are stored in metric-SI units. The Geoecology Data Base is currently fulfilling diverse ongoing research needs while it is being expanded and updated as needs and new data are identified. This report is both a documentation and a user's guide to the Geoecology Data Base. It describes the Data Base design, illustrates applications, provides examples of accessing the Data Base, and gives general information on the data set contents.

  8. Will environmental interventions affect the level of mastery motivation among children with disabilities? A preliminary study.

    PubMed

    Waldman-Levi, Amiya; Erez, Asnat Bar-Haim

    2015-03-01

    Children with developmental disabilities tend to demonstrate lower levels of mastery motivation in comparison with typically developing children. The goal of this study was to investigate the effect of physical and social environmental interventions on the mastery motivation of children with disabilities. Participants included 19 children (from two classes) with disabilities between the ages of 2-4 years from an educational rehabilitation centre. The Individualized Assessment of Mastery Motivation was used to assess the level of mastery motivation; the Early Childhood Environment Rating Scale - Revised and the Teacher-Child Interaction Observation were used to assess the physical and social environments. A counterbalance study design was used such that the children from the two classes received two phases of intervention, social and physical environmental interventions. The study's results point to the advantage of the social intervention, over the physical one, in improving the child's mastery motivation. However, the results lend support for the efficacy of using both aspects of environmental changes to the overall persistent score. The study findings, although preliminary, demonstrate the efficacy of providing both social and physical environmental interventions to improve mastery motivation.

  9. How environmental conditions affect canopy leaf-level photosynthesis in four deciduous tree species

    SciTech Connect

    Bassow, S.L.; Bazzaz, F.A.

    1998-12-01

    Species composition of temperate forests vary with successional age and seems likely to change in response to significant global climate change. Because photosynthesis rates in co-occurring tree species can differ in their sensitivity to environmental conditions, these changes in species composition are likely to alter the carbon dynamics of temperate forests. To help improve their understanding of such atmosphere-biosphere interactions, the authors explored changes in leaf-level photosynthesis in a 60--70 yr old temperate mixed-deciduous forest in Petersham, Massachusetts (USA). Diurnally and seasonally varying environmental conditions differentially influenced in situ leaf-level photosynthesis rates in the canopies of four mature temperate deciduous tree species: red oak (Quercus rubra), red maple (Acer rubrum), white birch (Betula papyrifera), and yellow birch (Betula alleghaniensis). The authors measured in situ photosynthesis at two heights within the canopies through a diurnal time course on 7 d over two growing seasons. They simultaneously measured a suite of environmental conditions surrounding the leaf at the time of each measurement. The authors used path analysis to examine the influence of environmental factors on in situ photosynthesis in the tree canopies.

  10. Environmental radiation monitoring of low-level wastes by the State of Washington

    SciTech Connect

    Conklin, A.W.; Mooney, R.R.; Erickson, J.L.

    1989-11-01

    The Washington State Department of Health, as the state`s regulatory agency for radiation, monitors several forms of low-level radioactive wastes. The monitoring is done to assess the potential impact on the environment and on public health. The emphasis of the monitoring program is placed on the solid and liquid wastes from defense activities on the Hanford Reservation, commercial wastes at the site located on leased land at Hanford and uranium mill tailings in Northeastern Washington. Although not classified as low-level waste, monitoring is also periodically conducted at selected landfills and sewage treatment facilities and other licensees, where radioactive wastes are known or suspected to be present. Environmental pathways associated with waste disposal are monitored independently, and/or in conjunction with the waste site operators to verify their results and evaluate their programs. The Department also participates in many site investigations conducted by site operators and other agencies, and conducts it`s own special investigations when deemed necessary. Past investigations and special projects have included allegations of adverse environmental impact of I-129, uranium in ground water, impacts of wastes on the agricultural industry, radioactivity in seeps into the Columbia River from waste sites, identifying lost waste sites at Hanford, differentiating groundwater contamination from defense versus commercial sources, and radioactivity in municipal landfills and sewers. The state`s environmental radiation monitoring program has identified and verified a number of environmental problems associated with radioactive waste disposal, but has, to date, identified no adverse offsite impacts to public health.

  11. Clinical Relevance of Cytokines Gene Polymorphisms and Protein Levels in Gingival Cervical Fluid from Chronic Periodontitis Patients.

    PubMed

    Lavu, Vamsi; Venkatesan, Vettriselvi; Venugopal, Priyanka; Lakkakula, Bhaskar Venkata Kameswara Subrahmanya; Paul, Solomon Franklin Durairaj; Peria, Kumarasamy; Rao, Suresh Ranga

    2017-03-01

    Cytokines are suggested to play a role in periodontitis. To determine and compare the levels of Interleukin-1 beta (IL-1β) and Tumor necrosis factor alpha (TNF-α) in gingival crevicular fluid (GCF) samples amongst healthy individuals and those with chronic periodontitis. Further to compare the GCF cytokine levels in three genotype classes defined by the respective gene polymorphisms. The study was conducted on 41 chronic periodontitis patients and 40 healthy volunteers. IL-1β and TNF-α were quantified in GCF by cytometric bead array. DNA was extracted from peripheral blood samples and genotyping of IL1B +3954C/T (rs1143634) IL1B -511G/A (rs16944), TNFA -1031T/C (rs1799964) and TNFA -863C/A (rs1800630) polymorphisms were performed using Sanger sequencing and Taqman SNP genotyping assays methods. Both IL-1β and TNF-α levels were significantly higher in chronic periodontitis group compared to the controls. IL-1β and TNF-α levels did not significantly differ in genotype classes of the respective polymorphism (IL1B -511G/A, TNFA -1031T/C and TNFA -863C/A). However, individuals with CT genotype of IL1B +3954C/T showed higher levels of IL-1β in the gingival crevicular fluid (ANOVA p<0.05). The results of this study revealed the presence of higher levels of IL-1β and TNF-α in subjects with periodontitis and genetic control of IL-1β levels in our samples of Indians.

  12. The environmental light influences the circulatory levels of retinoic acid and associates with hepatic lipid metabolism.

    PubMed

    Pang, Wenqiang; Li, Chunying; Zhao, Yue; Wang, Shiming; Dong, Wei; Jiang, Pengjiu; Zhang, Jianfa

    2008-12-01

    Environmental light is involved in the regulation of photochemical reaction in mouse retina. It remains unclear whether light-mediated increase in all-trans retinoic acid (ATRA) synthesis in retina will result in altering the circulatory levels of ATRA and regulating downstream gene expression and physiological function. Here we showed circulatory levels of ATRA decreased in mice under constant darkness and elevated by light exposure. Fat gene pancreatic lipase-related protein 2 (mPlrp2) and its partner procolipase (mClps), but not hepatic lipase (mHl), activated in livers for responding to lack of light illuminating. Light-triggered alterations in circulatory ATRA levels regulated ecto-5'-nucleotidase gene expression by retinoic acid receptor retinoic acid receptor-alpha and modulated 5'-AMP levels in blood and were associated with mPlrp2 and mClps expression in the livers. Mice deficient in adenosine receptors displayed mPlrp2 and mClps expression in livers under 12-h light, 12-h dark cycles. Caffeine blocked adenosine receptors and induced hepatic mPlrp2 and mClps expression in wild-type mice. Mice activated in hepatic mPlrp2 and mClps expression lowered hepatic and serum lipid levels and markedly elevated circulatory levels of all-trans retinol. Our results suggest environmental light influence hepatic lipid homeostasis by light-modulated retinoic acid signaling associated with mPlrp2 and mClps gene expression in livers.

  13. Training Tomorrow's Environmental Journalists: Assessing the Extent of Environmental-Themed Training in College-Level Journalism Programs

    ERIC Educational Resources Information Center

    Schmidt, Hans C.

    2017-01-01

    While the scale of the environmental problems facing the planet mean that effective environmental journalism is now more important than ever, the environmental beat can be extremely challenging for journalists. One way to address this is by providing specialized training for future journalists. This study involves an investigation of the extent to…

  14. Establishing the Biological Relevance of Dipentyl Phthalate Reductions in Fetal Rat Testosterone Production and Plasma and Testis Testosterone Levels

    EPA Science Inventory

    Phthalate esters (PEs) constitute a large class of compounds that are used for many consumer product applications. Many of the C2-C7 di-ortho PEs reduce fetal testicular hormone and gene expression levels in rats resulting in adverse effects seen later in life but it appears that...

  15. Establishing the Biological Relevance of Dipentyl Phthalate Reductions in Fetal Rat Testosterone Production and Plasma and Testis Testosterone Levels

    EPA Science Inventory

    Phthalate esters (PEs) constitute a large class of compounds that are used for many consumer product applications. Many of the C2-C7 di-ortho PEs reduce fetal testicular hormone and gene expression levels in rats resulting in adverse effects seen later in life but it appears that...

  16. Environmental urban lead exposure and blood lead levels in children of Mexico City.

    PubMed Central

    Romieu, I; Carreon, T; Lopez, L; Palazuelos, E; Rios, C; Manuel, Y; Hernandez-Avila, M

    1995-01-01

    Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics. PMID:8605853

  17. Environmental variables and levels of exhaled carbon monoxide and carboxyhemoglobin in elderly people taking exercise.

    PubMed

    Salicio, Marcos Adriano; Mana, Viviane Aparecida Martins; Fett, Waléria Christiane Rezende; Gomes, Luciano Teixeira; Botelho, Clovis

    2016-04-01

    This article aims to analyze levels of exhaled carbon monoxide, carboxyhemoglobinand cardiopulmonary variables in old people practicing exercise in external environments, and correlate them with climate and pollution factors. Temporal ecological study with118 active elderly people in the city of Cuiabá, in the state of Mato Grosso, Brazil. Data were obtained on use of medication, smoking, anthropometric measurements, spirometry, peak flow, oxygen saturation, heart rate, exhaled carbon monoxide, carboxyhemoglobin, climate, number of farm fires and pollution. Correlations were found between on the one hand environmental temperature, relative humidity of the air and number of farmers' fires, and on the other hand levels of carbon monoxide exhaled and carboxyhemoglobin (p < 0.05).There was a correlation between heart rate and changes in environmental temperature, time of exposure to the sun and relative humidity (p < 0.05). In elderly people, environmental factors influence levels of exhaled carbon monoxide, carboxyhemoglobin and heart rate. There is thus a need for these to be monitored during exercise. The use of a carbon monoxide monitor to evaluate exposure to pollutants is suggested.

  18. Environmental urban lead exposure and blood lead levels in children of Mexico City.

    PubMed

    Romieu, I; Carreon, T; Lopez, L; Palazuelos, E; Rios, C; Manuel, Y; Hernandez-Avila, M

    1995-11-01

    Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics.

  19. [THE STUDY OF MANIFESTATIONS OF ENVIRONMENTAL HAZARDS AT THE REGIONAL LEVEL].

    PubMed

    Shmandiy, V M; Kharlamova, E V; Rugas, T E

    2015-01-01

    Elaborated methodological approaches to the monitoring of the state of ecological safety are based on the use of systems analysis of conditions and consistent patterns of the formation of the ecological danger search for effective means and methods of safety management. Ecological hazard is considered as a hierarchical structure, consisting of types, classes, species and subsubspecies. In industrially developed regions the most significant are technogenic and sociogenic classes. The sociogenic class of danger was proved to be primary in its formation, as the level of environmental awareness is largely determined by the degree of impact on human health and environment, manifestations of the danger of other classes are depend on it. When analyzing the state of danger there was applied the anthropocentric approach. There was used an assembly of characteristics considering the health status of the population of the certain territory under the influence of factors of environmental hazard. On the base of the colligation of literature data and the results of own observations there was suggested a generalized index of the state of the population'S health in socio-economic areas, there were selected zones with differing level of the technogenic loads and also rural areas beyond objects of technogenic impact. On results of studies there was proved the relationship between the level of the environmental hazard and state of the population's in various socio-economic zones.

  20. Effects of high CO2 levels on dynamic photosynthesis: carbon gain, mechanisms, and environmental interactions.

    PubMed

    Tomimatsu, Hajime; Tang, Yanhong

    2016-05-01

    Understanding the photosynthetic responses of terrestrial plants to environments with high levels of CO2 is essential to address the ecological effects of elevated atmospheric CO2. Most photosynthetic models used for global carbon issues are based on steady-state photosynthesis, whereby photosynthesis is measured under constant environmental conditions; however, terrestrial plant photosynthesis under natural conditions is highly dynamic, and photosynthetic rates change in response to rapid changes in environmental factors. To predict future contributions of photosynthesis to the global carbon cycle, it is necessary to understand the dynamic nature of photosynthesis in relation to high CO2 levels. In this review, we summarize the current body of knowledge on the photosynthetic response to changes in light intensity under experimentally elevated CO2 conditions. We found that short-term exposure to high CO2 enhances photosynthetic rate, reduces photosynthetic induction time, and reduces post-illumination CO2 burst, resulting in increased leaf carbon gain during dynamic photosynthesis. However, long-term exposure to high CO2 during plant growth has varying effects on dynamic photosynthesis. High levels of CO2 increase the carbon gain in photosynthetic induction in some species, but have no significant effects in other species. Some studies have shown that high CO2 levels reduce the biochemical limitation on RuBP regeneration and Rubisco activation during photosynthetic induction, whereas the effects of high levels of CO2 on stomatal conductance differ among species. Few studies have examined the influence of environmental factors on effects of high levels of CO2 on dynamic photosynthesis. We identified several knowledge gaps that should be addressed to aid future predictions of photosynthesis in high-CO2 environments.

  1. Integrated analysis of transcript-level regulation of metabolism reveals disease-relevant nodes of the human metabolic network.

    PubMed

    Galhardo, Mafalda; Sinkkonen, Lasse; Berninger, Philipp; Lin, Jake; Sauter, Thomas; Heinäniemi, Merja

    2014-02-01

    Metabolic diseases and comorbidities represent an ever-growing epidemic where multiple cell types impact tissue homeostasis. Here, the link between the metabolic and gene regulatory networks was studied through experimental and computational analysis. Integrating gene regulation data with a human metabolic network prompted the establishment of an open-sourced web portal, IDARE (Integrated Data Nodes of Regulation), for visualizing various gene-related data in context of metabolic pathways. Motivated by increasing availability of deep sequencing studies, we obtained ChIP-seq data from widely studied human umbilical vein endothelial cells. Interestingly, we found that association of metabolic genes with multiple transcription factors (TFs) enriched disease-associated genes. To demonstrate further extensions enabled by examining these networks together, constraint-based modeling was applied to data from human preadipocyte differentiation. In parallel, data on gene expression, genome-wide ChIP-seq profiles for peroxisome proliferator-activated receptor (PPAR) γ, CCAAT/enhancer binding protein (CEBP) α, liver X receptor (LXR) and H3K4me3 and microRNA target identification for miR-27a, miR-29a and miR-222 were collected. Disease-relevant key nodes, including mitochondrial glycerol-3-phosphate acyltransferase (GPAM), were exposed from metabolic pathways predicted to change activity by focusing on association with multiple regulators. In both cell types, our analysis reveals the convergence of microRNAs and TFs within the branched chain amino acid (BCAA) metabolic pathway, possibly providing an explanation for its downregulation in obese and diabetic conditions.

  2. Integrated analysis of transcript-level regulation of metabolism reveals disease-relevant nodes of the human metabolic network

    PubMed Central

    Galhardo, Mafalda; Sinkkonen, Lasse; Berninger, Philipp; Lin, Jake; Sauter, Thomas; Heinäniemi, Merja

    2014-01-01

    Metabolic diseases and comorbidities represent an ever-growing epidemic where multiple cell types impact tissue homeostasis. Here, the link between the metabolic and gene regulatory networks was studied through experimental and computational analysis. Integrating gene regulation data with a human metabolic network prompted the establishment of an open-sourced web portal, IDARE (Integrated Data Nodes of Regulation), for visualizing various gene-related data in context of metabolic pathways. Motivated by increasing availability of deep sequencing studies, we obtained ChIP-seq data from widely studied human umbilical vein endothelial cells. Interestingly, we found that association of metabolic genes with multiple transcription factors (TFs) enriched disease-associated genes. To demonstrate further extensions enabled by examining these networks together, constraint-based modeling was applied to data from human preadipocyte differentiation. In parallel, data on gene expression, genome-wide ChIP-seq profiles for peroxisome proliferator-activated receptor (PPAR) γ, CCAAT/enhancer binding protein (CEBP) α, liver X receptor (LXR) and H3K4me3 and microRNA target identification for miR-27a, miR-29a and miR-222 were collected. Disease-relevant key nodes, including mitochondrial glycerol-3-phosphate acyltransferase (GPAM), were exposed from metabolic pathways predicted to change activity by focusing on association with multiple regulators. In both cell types, our analysis reveals the convergence of microRNAs and TFs within the branched chain amino acid (BCAA) metabolic pathway, possibly providing an explanation for its downregulation in obese and diabetic conditions. PMID:24198249

  3. Structured Multi-level Data Fusion and Modelling of Heterogeneous Environmental Data for Future Internet Applications

    NASA Astrophysics Data System (ADS)

    Sabeur, Zoheir; Chakravarthy, Ajay; Bashevoy, Maxim; Modafferi, Stefano

    2013-04-01

    The rapid increase in environmental observations which are conducted by Small to Medium Enterprise communities and volunteers using affordable in situ sensors at various scales, in addition to the more established observatories set up by environmental and space agencies using airborne and space-borne sensing technologies is generating serious amounts of BIG data at ever increasing speeds. Furthermore, the emergence of Future Internet technologies and the urgent requirements for the deployment of specific enablers for the delivery of processed environmental knowledge in real-time with advanced situation awareness to citizens has reached paramount importance. Specifically, it has become highly critical now to build and provide services which automate the aggregation of data from various sources, while surmounting the semantic gaps, conflicts and heterogeneity in data sources. The early stage aggregation of data will enable the pre-processing of data from multiple sources while reconciling the temporal gaps in measurement time series, and aligning their respective a-synchronicities. This low level type of data fusion process needs to be automated and chained to more advanced level of data fusion services specialising in observation forecasts at spaces where sensing is not deployed; or at time slices where sensing has not taken place yet. As a result, multi-level fusion services are required among the families of specific enablers for monitoring environments and spaces in the Future Internet. These have been intially deployed and piloted in the ongoing ENVIROFI project of the FI-PPP programme [1]. Automated fusion and modelling of in situ and remote sensing data has been set up and the experimentation successfully conducted using RBF networks for the spatial fusion of water quality parameters measurements from satellite and stationary buoys in the Irish Sea. The RBF networks method scales for the spatial data fusion of multiple types of observation sources. This

  4. Association of Campylobacter spp. levels between chicken grow-out environmental samples and processed carcasses.

    PubMed

    Schroeder, Matthew W; Eifert, Joseph D; Ponder, Monica A; Schmale, David G

    2014-03-01

    Campylobacter spp. have been isolated from live poultry, production environments, processing facilities, and raw poultry products. Environmental sampling in a poultry grow-out house, combined with carcass rinse sampling from the same flock, may provide a relative relationship between pre- and postharvest Campylobacter contamination. Air samples, fecal/litter samples, and feed/drink line samples were collected from 4 commercial chicken grow-out houses in western Virginia between September 2011 and January 2012. Birds from each sampled house were the first flock slaughtered the following day and were then sampled by postchill carcass rinses. Campylobacter, from postenrichment samples, was detected in 27% (32/120) of house environmental samples and 37.5% (45/120) of carcass rinse samples. All environmental sample types from each house included at least one positive sample except the house 2 air samples. The sponge sample method was found to have a significantly higher (P < 0.05) proportion of Campylobacter-positive samples (45%) than the fecal/litter samples (20%) and air samples (15%) when sample types of all the houses were compared. The proportion positive for the fecal/litter samples postenrichment, for each flock, had the highest correlation (0.85) to the proportion of positive carcass rinse samples for each flock. Environmental samples from house 1 and associated carcass rinses accounted for the largest number of Campylobacter positives (29/60). The fewest number of Campylobacter positives, based on both house environmental (4/30) and carcass rinse samples (8/30), was detected from flock B. The results of this study suggest that environmental sampling in a poultry grow-out house, combined with carcass rinse sampling from the same flock, have the potential to provide an indication of Campylobacter contamination and transmission. Campylobacter qualitative levels from house and processing plant samples may enable the scheduled processing of flocks with lower

  5. Expression levels of the ABCG2 multidrug transporter in human erythrocytes correspond to pharmacologically relevant genetic variations.

    PubMed

    Kasza, Ildikó; Várady, György; Andrikovics, Hajnalka; Koszarska, Magdalena; Tordai, Attila; Scheffer, George L; Németh, Adrienn; Szakács, Gergely; Sarkadi, Balázs

    2012-01-01

    We have developed a rapid, simple and reliable, antibody-based flow cytometry assay for the quantitative determination of membrane proteins in human erythrocytes. Our method reveals significant differences between the expression levels of the wild-type ABCG2 protein and the heterozygous Q141K polymorphic variant. Moreover, we find that nonsense mutations on one allele result in a 50% reduction in the erythrocyte expression of this protein. Since ABCG2 polymorphisms are known to modify essential pharmacokinetic parameters, uric acid metabolism and cancer drug resistance, a direct determination of the erythrocyte membrane ABCG2 protein expression may provide valuable information for assessing these conditions or for devising drug treatments. Our findings suggest that erythrocyte membrane protein levels may reflect genotype-dependent tissue expression patterns. Extension of this methodology to other disease-related or pharmacologically important membrane proteins may yield new protein biomarkers for personalized diagnostics.

  6. Expression Levels of the ABCG2 Multidrug Transporter in Human Erythrocytes Correspond to Pharmacologically Relevant Genetic Variations

    PubMed Central

    Kasza, Ildikó; Várady, György; Andrikovics, Hajnalka; Koszarska, Magdalena; Tordai, Attila; Scheffer, George L.; Németh, Adrienn; Szakács, Gergely; Sarkadi, Balázs

    2012-01-01

    We have developed a rapid, simple and reliable, antibody-based flow cytometry assay for the quantitative determination of membrane proteins in human erythrocytes. Our method reveals significant differences between the expression levels of the wild-type ABCG2 protein and the heterozygous Q141K polymorphic variant. Moreover, we find that nonsense mutations on one allele result in a 50% reduction in the erythrocyte expression of this protein. Since ABCG2 polymorphisms are known to modify essential pharmacokinetic parameters, uric acid metabolism and cancer drug resistance, a direct determination of the erythrocyte membrane ABCG2 protein expression may provide valuable information for assessing these conditions or for devising drug treatments. Our findings suggest that erythrocyte membrane protein levels may reflect genotype-dependent tissue expression patterns. Extension of this methodology to other disease-related or pharmacologically important membrane proteins may yield new protein biomarkers for personalized diagnostics. PMID:23166586

  7. Sex Differences in Macrophage Functions in Middle-Aged Rats: Relevance of Estradiol Level and Macrophage Estrogen Receptor Expression.

    PubMed

    Ćuruvija, Ivana; Stanojević, Stanislava; Arsenović-Ranin, Nevena; Blagojević, Veljko; Dimitrijević, Mirjana; Vidić-Danković, Biljana; Vujić, Vesna

    2017-06-01

    The aim of this study was to examine the influence of sex on age-related changes in phenotype and functional capacity of rat macrophages. The potential role of estradiol as a contributing factor to a sex difference in macrophage function with age was also examined. Thioglycollate-elicited peritoneal macrophages derived from the young (2 months old) and the naturally senescent intact middle-aged (16 months old) male and female rats were tested for cytokine secretion and antimicrobial activity (NO and H2O2 production and myeloperoxidase activity). Serum concentration of estradiol and the expression of estrogen receptor (ER)α and ERβ on freshly isolated peritoneal macrophages were also examined. Decreased secretion of IL-1β and IL-6 by macrophages from middle-aged compared to the young females was accompanied with the lesser density of macrophage ERα expression and the lower systemic level of estradiol, whereas the opposite was true for middle-aged male rats. Macrophages in the middle-aged females, even with the diminished circulating estradiol levels, produce increased amount of IL-6, and comparable amounts of IL-1β, TNF-α, and NO to that measured in macrophages from the middle-aged males. Age-related changes in macrophage phenotype and the antimicrobial activity were independent of macrophage ERα/ERβ expression and estradiol level in both male and female rats. Although our study suggests that the sex difference in the level of circulating estradiol may to some extent contribute to sex difference in macrophage function of middle-aged rats, it also points to more complex hormonal regulation of peritoneal macrophage activity in females.

  8. Experimental exposure of juvenile savannah monitors (Varanus exanthematicus) to an environmentally relevant mixture of three contaminants: effects and accumulation in tissues.

    PubMed

    Ciliberti, Alexandre; Martin, Samuel; Ferrandez, Eric; Belluco, Sara; Rannou, Benoit; Dussart, Céline; Berny, Philippe; de Buffrenil, Vivian

    2013-05-01

    Using varanids as indicators of pollution in African continental wetlands was previously proposed. The present study aimed at understanding experimentally how monitors absorb and accumulate pollutants and how they are affected. The relevance of non-destructive sampling was also evaluated. Savannah monitors (Varanus exanthematicus) were orally exposed during 6 months to a mixture of lead, 4,4'-dichlorodiphenyltrichloroethane (4,4'-DDT) and chlorpyrifos-ethyl (CPF) or to the vehicle only. Proportionally to their mass, exposed monitors received the same dose: 20 then 10 mg lead kg(-1), 2 then 0.5 mg CPF kg(-1) and 4 mg 4,4'-DDT kg(-1). Individuals surviving contamination were euthanized after 4 or 6 months of experiment. Tissues were analysed for lead by atomic absorption spectrophotometry and for DDT and CPF by gas chromatography. Exposed monitors absorbed all three pollutants but only lead (essentially in bone, tail tips and phalanxes) and 4,4'-DDT plus its main metabolites (essentially in fat and liver) accumulated. CPF killed ten individuals. Clear correlations occurred between the total quantity of lead or 4,4'-DDT administered and concentrations in tissues. Tail tips and skin samples are recommended non-destructive indicators for lead and organochlorine pesticides contamination, respectively. This work confirms that monitors can be used as relevant indicators of environmental pollution by lead and organochlorine pesticides. Although varanids withstand heavy lead and DDT contamination, our results suggest that CPF can be lethal at very low doses to the herpetofauna and emphasize the importance of considering all taxa in impact assessment studies, including reptiles.

  9. Grade-Level Differences in Future-Oriented Self-Concept During Early Adolescence: Potential Relevance to School Nursing.

    PubMed

    Stoddard, Sarah A; Pierce, Jennifer; Schmidt, Carissa J

    2016-12-01

    The middle school and early high school years are a time of significant development, including an increasing ability to envision oneself in the future. Little is known about how adolescents' future-oriented self-concept (i.e., possible selves) differs across grade levels, although this knowledge may aid in establishing rapport with students and building effective health promotion and risk reduction interventions. Therefore, this study explored grade-level differences in hoped for and feared possible selves in a sample of sixth- to ninth-grade students (n = 2,498; M age = 12.72, SD = 1.15; 51.3% female). Findings suggest that adolescents list a variety of possible selves, and the content differs according to grade level. These findings offer helpful insight for intervention work aimed at improving student outcomes and preventing risk behavior. Understanding what adolescents hope and fear for themselves in the future may be particularly beneficial for school nurses in identifying the unique challenges students experience and tailoring health promotion efforts. © The Author(s) 2016.

  10. Environmental noise levels affect the activity budget of the Florida manatee

    NASA Astrophysics Data System (ADS)

    Miksis-Olds, Jennifer L.; Donaghay, Percy L.; Miller, James H.; Tyack, Peter L.

    2005-09-01

    Manatees inhabit coastal bays, lagoons, and estuaries because they are dependent on the aquatic vegetation that grows in shallow waters. Food requirements force manatees to occupy the same areas in which human activities are the greatest. Noise produced from human activities has the potential to affect these animals by eliciting responses ranging from mild behavioral changes to extreme aversion. This study quantifies the behavioral responses of manatees to both changing levels of ambient noise and transient noise sources. Results indicate that elevated environmental noise levels do affect the overall activity budget of this species. The proportion of time manatees spend feeding, milling, and traveling in critical habitats changed as a function of noise level. More time was spent in the directed, goal-oriented behaviors of feeding and traveling, while less time was spent milling when noise levels were highest. The animals also responded to the transient noise of approaching vessels with changes in behavioral state and movements out of the geographical area. This suggests that manatees detect and respond to changes in environmental noise levels. Whether these changes legally constitute harassment and produce biologically significant effects need to be addressed with hypothesis-driven experiments and long-term monitoring. [For Animal Bioacoustics Best Student Paper Award.

  11. Editor's Highlight: Interactive Genotoxicity Induced by Environmentally Relevant Concentrations of Benzo(a)Pyrene Metabolites and Arsenite in Mouse Thymus Cells.

    PubMed

    Xu, Huan; Lauer, Fredine T; Liu, Ke Jian; Hudson, Laurie G; Burchiel, Scott W

    2016-11-01

    Arsenic and polycyclic aromatic hydrocarbon (PAH) exposures affect many people worldwide leading to cancer and other diseases. Arsenite (As(+3)) and certain PAHs are known to cause genotoxicity. However, there is limited information on the interactions between As(+3) and PAHs at environmentally relevant concentrations. The thymus is the primary immune organ for T cell development in mammals. Our previous studies showed that environmentally relevant concentrations of As(+3) induce genotoxicity in mouse thymus cells through Poly(ADP-ribose) polymerase (PARP) inhibition. Certain PAHs, such as the metabolites of benzo(a)pyrene (BaP), are known to cause DNA damage by forming DNA adducts. In the present study, primary mouse thymus cells were examined for DNA damage following 18 hr in vitro treatments with 5 or 50 nM As(+3) and 100 nM BaP, benzo[a]pyrene-7,8-dihydrodiol (BP-Diol), or benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). An interactive increase in genotoxicity and apoptosis were observed following treatments with 5 nM As (+)  (3 )+( )100 nM BP-diol and 50 nM As (+)  (3 )+( )100 nM BPDE. We attribute the increase in DNA damage to inhibition of PARP inhibition leading to decreased DNA repair. To further support this hypothesis, we found that a PARP inhibitor, 3,4-dihydro-5[4-(1-piperindinyl) butoxyl]-1(2H)-isoquinoline (DPQ), also interacted with BP-diol to produce an increase in DNA damage. Interestingly, we also found that As(+3) and BP-diol increased CYP1A1 and CYP1B1 expression, suggesting that increased PAH metabolism may also contribute to genotoxicity. In summary, these results show that the suppression of PARP activity and induction of CYP1A1/CYP1B1 may act together to increase DNA damage produced by As(+3) and PAHs.

  12. Low-Volatility Model Demonstrates Humidity Affects Environmental Toxin Deposition on Plastics at a Molecular Level.

    PubMed

    Hankett, Jeanne M; Collin, William R; Yang, Pei; Chen, Zhan; Duhaime, Melissa

    2016-02-02

    Despite the ever-increasing prevalence of plastic debris and endocrine disrupting toxins in aquatic ecosystems, few studies describe their interactions in freshwater environments. We present a model system to investigate the deposition/desorption behaviors of low-volatility lake ecosystem toxins on microplastics in situ and in real time. Molecular interactions of gas-phase nonylphenols (NPs) with the surfaces of two common plastics, poly(styrene) and poly(ethylene terephthalate), were studied using quartz crystal microbalance and sum frequency generation vibrational spectroscopy. NP point sources were generated under two model environments: plastic on land and plastic on a freshwater surface. We found the headspace above calm water provides an excellent environment for NP deposition and demonstrate significant NP deposition on plastic within minutes at relevant concentrations. Further, NP deposits and orders differently on both plastics under humid versus dry environments. We attributed the unique deposition behaviors to surface energy changes from increased water content during the humid deposition. Lastly, nanograms of NP remained on microplastic surfaces hours after initial NP introduction and agitating conditions, illustrating feasibility for plastic-bound NPs to interact with biota and surrounding matter. Our model studies reveal important interactions between low-volatility environmental toxins and microplastics and hold potential to correlate the environmental fate of endocrine disrupting toxins in the Great Lakes with molecular behaviors.

  13. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels.

    PubMed

    Ragettli, Martina S; Goudreau, Sophie; Plante, Céline; Perron, Stéphane; Fournier, Michel; Smargiassi, Audrey

    2015-12-29

    There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels-LAeq24h and day-evening-night equivalent noise levels-Lden) for each study participant was determined using a statistical noise model (land use regression-LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07-1.13) and 1.04 (1.02-1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

  14. Response of Lemna gibba L. to high and environmentally relevant concentrations of ibuprofen: Removal, metabolism and morpho-physiological traits for biomonitoring of emerging contaminants.

    PubMed

    Di Baccio, D; Pietrini, F; Bertolotto, P; Pérez, S; Barcelò, D; Zacchini, M; Donati, E

    2017-04-15

    The increasing worldwide consumption of pharmaceuticals and personal care products such as ibuprofen (IBU) is leading to the widespread and persistent occurrence of these chemicals and their transformation products in soils and waters. Although at low concentrations, the continuous discharge of these micropollutants and the incomplete removal by the actual wastewater treatments can provoke accumulation in the environment with risks for the trophic chain. Non-target organisms as duckweed can be used for the environmental monitoring of pharmaceutical emerging contaminants. In this work, plants of Lemna gibba L. were exposed to high (0.20 and 1mgL(-1)) and environmentally relevant (0.02mgL(-1)) concentrations of IBU to investigate their removal and metabolization capacity. The main oxidized IBU metabolites in humans (hydroxy-IBU and carboxy-IBU) were determined in the intact plants and in the growth solutions, together with non-destructive physiological parameters and phytotoxic indicators. The IBU uptake increased with the increasing of IBU concentration in the medium, but the relative accumulation of the pharmaceutical and generation of hydroxy-IBU was higher in presence of the lower IBU treatments. Carboxy-IBU was not found in the plant tissue and solutions. The changes observed in growth and photosynthetic performances were not able to induce phyto-toxic effects. Apart from a mean physical-chemical degradation of 8.2%, the IBU removal by plants was highly efficient (89-92.5%) in all the conditions tested, highlighting the role of L. gibba in the biodegradation of emerging contaminants.

  15. Interethnic differences in the relevance of CYP2C9 genotype and environmental factors for diclofenac metabolism in Hispanics from Cuba and Spain.

    PubMed

    Llerena, A; Alvarez, M; Dorado, P; González, I; Peñas-LLedó, E; Pérez, B; Cobaleda, J; Calzadilla, L R

    2014-06-01

    The aims of this study were to evaluate the diclofenac metabolism in Hispanics from Cuba and Spain and its relation to ethnicity, CYP2C9 genotypes and environmental factors. Diclofenac hydroxylation capacity (concentration ratios of diclofenac/metabolites in 8-h urine) was studied in 160 Cuban (classified as 76 Cuban-Whites-CWs and 84 Cuban-Mestizos-CMs) and 148 Spaniard (SPs) healthy volunteers. Diclofenac and its main metabolites, 4'-hydroxy (OH), 3'-OH and 5-OH diclofenac, and CYP2C9*2 to *6 and *8 alleles were also determined in 132 and 128 CWs and CMs, respectively. Gender, tobacco, caffeine and ethanol consumption were also evaluated. The mean diclofenac/4'-OH diclofenac ratio was higher in CMs (0.72±0.25) than in CWs (0.64±0.20; P<0.05) and SPs (0.57±0.26; P<0.001). The mean diclofenac/4'-OH diclofenac ratio was higher (P<0.05) in subjects with CYP2C9*1/*3 (0.77±0.19; n=22) and CYP2C9*1/*8 (0.93±0.33; n=4) genotypes than with CYP2C9*1/*1 (0.65±0.24; n=90). Environmental factors did not seem to influence the diclofenac metabolism in these populations. The present findings show for the first time interethnic differences between Hispanic groups in urinary diclofenac/4'-OH diclofenac ratios, and the relevance of CYP2C9*3 and CYP2C9*8 alleles.

  16. Contrasting correlation patterns between environmental factors and chlorophyll levels in the global ocean

    NASA Astrophysics Data System (ADS)

    Feng, Jianfeng; Durant, Joël. Marcel; Stige, Leif Chr.; Hessen, Dag Olav; Hjermann, Dag Øystein; Zhu, Lin; Llope, Marcos; Stenseth, Nils Chr.

    2015-12-01

    In this study we analyze large-scale satellite-derived data using generalized additive models to characterize the global correlation patterns between environmental forcing and marine phytoplankton biomass. We found systematic differences in the relationships between key environmental drivers (temperature, light, and wind) and ocean chlorophyll in the subtropical/tropical and temperate oceans. For the subtropical/tropical and equatorial oceans, the chlorophyll generally declined with increasing temperature and light, while in temperate oceans, chlorophyll was best explained by bell-shaped or positive functions of temperature and light. The relationship between chlorophyll and wind speed is generally positive in low-latitude oceans and bell shaped in temperate oceans. Our analyses also demonstrated strong and geographically consistent positive autoregressive effects of chlorophyll from 1 month to the next and negative autoregressive effects for measurements 2 months apart. These findings imply possibly different regional phytoplankton responses to environmental forcing, suggesting that future environmental change could affect the tropical and temperate upper ocean chlorophyll levels differently.

  17. Vulnerability of US thermoelectric power generation to climate change when incorporating state-level environmental regulations

    NASA Astrophysics Data System (ADS)

    Liu, Lu; Hejazi, Mohamad; Li, Hongyi; Forman, Barton; Zhang, Xiao

    2017-08-01

    Previous modelling studies suggest that thermoelectric power generation is vulnerable to climate change, whereas studies based on historical data suggest the impact will be less severe. Here we explore the vulnerability of thermoelectric power generation in the United States to climate change by coupling an Earth system model with a thermoelectric power generation model, including state-level representation of environmental regulations on thermal effluents. We find that the impact of climate change is lower than in previous modelling estimates due to an inclusion of a spatially disaggregated representation of environmental regulations and provisional variances that temporarily relieve power plants from permit requirements. More specifically, our results indicate that climate change alone may reduce average generating capacity by 2-3% by the 2060s, while reductions of up to 12% are expected if environmental requirements are enforced without waivers for thermal variation. Our work highlights the significance of accounting for legal constructs and underscores the effects of provisional variances in addition to environmental requirements.

  18. Impact of Sublethal Levels of Environmental Pollutants Found in Sewage Sludge on a Novel Caenorhabditis elegans Model Biosensor

    PubMed Central

    Amezaga, Maria R.; Petra, Eleni; Frost, Andrew; Duff, Elizabeth I.; Rhind, Stewart M.; Fowler, Paul A.; Glover, L. Anne

    2012-01-01

    A transgenic strain of the model nematode Caenorhabditis elegans in which bioluminescence reports on relative, whole-organism ATP levels was used to test an environmentally-relevant mixture of pollutants extracted from processed sewage sludge. Changes in bioluminescence, following exposure to sewage sludge extract, were used to assess relative ATP levels and overall metabolic health. Reproductive function and longevity were also monitored. A short (up to 8 h) sublethal exposure of L4 larval stage worms to sewage sludge extract had a concentration-dependent, detrimental effect on energy status, with bioluminescence decreasing to 50–60% of the solvent control (1% DMSO). Following longer exposure (22–24 h), the energy status of the nematodes showed recovery as assessed by bioluminescence. Continuous exposure to sewage sludge extract from the L4 stage resulted in a shorter median lifespan relative to that of solvent or medium control animals, but only in the presence of 400–600 µM 5-fluoro-2′-deoxyuridine (FUdR), which was incorporated to inhibit reproduction. This indicated that FUdR increased lifespan, and that the effect was counteracted by SSE. Exposure to sewage sludge extract from the L1 stage led to slower growth and a delayed onset of egg laying. When L1 exposed nematodes reached the reproductive stage, no effect on egg laying rate or egg number in the uterus was observed. DMSO itself (1%) had a significant inhibitory effect on growth and development of C. elegans exposed from the L1 stage and on reproduction when exposed from the L4 stage. Results demonstrate subtle adverse effects on C. elegans of a complex mixture of environmental pollutants that are present, individually, in very low concentrations and indicate that our biosensor of energy status is a novel, sensitive, rapid, quantitative, whole-organism test system which is suitable for high throughput risk assessment of complex pollutant mixtures. PMID:23056324

  19. Speciation, Dissolution, and Redox Reactions of Chromium Relevant to Pretreatment and Separation of High-Level Tank Wastes

    SciTech Connect

    Clark Sue B.; Dhanpat Rai; Linfeng Rao

    2005-04-20

    Chromium, one of the problematic elements in tank sludges, is considered the most important constituent in defining the total volume of high-level radioactive waste (HLW) glass. Current sludge washing processes (e.g. caustic leaching, 3 M NaOH) are not effective in removing Cr. This inefficient removal would result in production of an unacceptably large volume of HLW glass and thus a tremendous increase in the cost of waste disposal. This proposed research seeks to develop fundamental data for chromium (Cr) reactions that are not currently available but are essential for developing effective methodologies for removing Cr form high-level waste (HLW). Our objectives are to study (1) the dissolution of several solid phases (e.g., CrOOH, Cr2O3(c), Cr(OH)3, and Fe and Cr, binary hydroxides, identified to be important from sludge leaching studies) in highly alkaline solutions and in the presence of other electrolytes (e.g., carbonate, phosphate, sulfate, nitrite), and (2) the effect of the nature of Cr solid phases and aqueous species on their redox reactivity with a variety of potential oxidants (e.g., H2o2, persulfate, O2, and ferrate). This information will provide critical support for developing enhanced pretreatment strategies for removing Cr from HLW and will achieve a major cost reduction HLW disposal.

  20. Speciation, Dissolution, and Redox Reactions of Chromium Relevant to Pretreatment and Separation of High-Level Tank Wastes

    SciTech Connect

    Rai Dhanpat; Rao Linfeng

    2005-09-30

    Chromium, one of the problematic elements in tank sludges, is considered the most important constituent in defining the total volume of high-level radioactive waste (HLW) glass. Current sludge washing processes (e.g. caustic leaching, 3 M NaOH) are not effective in removing Cr. Such inefficient removal would result in the production of an unacceptably large volume of HLW glass and thus a tremendous increase in the cost of waste disposal. This proposed research seeks to develop fundamental data for chromium (Cr) reactions that are not currently available but are essential for developing effective methodologies for removing Cr form high-level waste (HLW). Our objectives are to study (1) the dissolution of several solid phases (e.g., CrOOH, Cr2O3(c), Cr(OH)3, and Fe and Cr, binary hydroxides, identified to be important from sludge leaching studies) in highly alkaline solutions and in the presence of other electrolytes (e.g., carbonate, phosphate, sulfate, nitrite), and (2) the effect of the nature of Cr solid phases and aqueous species on their redox reactivity with a variety of potential oxidants (H2O2, persulfate, hypochlorite, etc.). This information will provide critical support for developing enhanced pretreatment strategies for removing Cr from HLW and will achieve a major cost reduction in HLW disposal.