WorldWideScience

Sample records for assessing chemical effects

  1. Health effects assessment of chemical exposures: ARIES methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, L; Montero, M.; Rabago, I.; Vidania, R.

    1995-07-01

    In this work, we present ARIES* update: a system designed in order to facilitate the human health effects assessment produced by accidental release of toxic chemicals. The first version of ARIES was developed in relation to 82/501/EEC Directive about mayor accidents in the chemical industry. So, the first aim was the support of the effects assessment derived for the chemicals included into this directive. From this establishment, it was considered acute exposures for high concentrations. In this report, we present the actual methodology for considering other type of exposures, such as environmental and occupational. Likewise other versions, the methodology comprises two approaches: quantitative and qualitative assessments. Quantitative assessment incorporates the mathematical algorithms useful to evaluate the effects produced by the most important routes of exposure: inhalation, ingestion, eye contact and skin absorption, in a short, medium and long term. It has been included models that realizes an accurate quantification of doses, effects,... and so on, such as simple approaches when the available information is not enough. Qualitative assessment, designed in order to complement or replace the previous one, is incorporated into an informatics system, developed in Clipper. It executes and displays outstanding and important toxicological information of about 100 chemicals. This information comes from ECDIN (Environmental Chemicals Data and Information Network) database through a collaboration with JRC-ISPRA working group. (Author) 24 refs.

  2. Assessing the effects of chemicals on aquatic microbial ecosystems

    NARCIS (Netherlands)

    Rocha Dimitrov, M.

    2016-01-01

    Nowadays, an increasing number of synthetic chemicals are used in a vast range of applications. When reflecting about our daily activities, it is not difficult to realize how much of our life style is dependent on synthetic chemicals. From the food we eat, medicines we take to the health care produc

  3. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    Science.gov (United States)

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed.

  4. Chemical mixtures and environmental effects: a pilot study to assess ecological exposure and effects in streams

    Science.gov (United States)

    Buxton, Herbert T.; Reilly, Timothy J.; Kuivila, Kathryn M.; Kolpin, Dana W.; Bradley, Paul M.; Villeneuve, Daniel L.; Mills, Marc A.

    2015-01-01

    Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

  5. The Chemical Aquatic Fate and Effects database (CAFE), a tool that supports assessments of chemical spills in aquatic environments.

    Science.gov (United States)

    Bejarano, Adriana C; Farr, James K; Jenne, Polly; Chu, Valerie; Hielscher, Al

    2016-06-01

    The Chemical Aquatic Fate and Effects (CAFE) database is a centralized repository that allows for rapid and unrestricted access to data. Information in CAFE is integrated into a user-friendly tool with modules containing fate and effects data for 32 377 and 4498 chemicals, respectively. Toxicity data are summarized in the form of species sensitivity distributions (SSDs) with associated 1st and 5th percentile hazard concentrations (HCs). An assessment of data availability relative to reported chemical incidents showed that CAFE had fate and toxicity data for 32 and 20 chemicals, respectively, of 55 chemicals reported in the US National Response Center database (2000-2014), and fate and toxicity data for 86 and 103, respectively, of 205 chemicals reported by the National Oceanic and Atmospheric Administration (2003-2014). Modeled environmental concentrations of 2 hypothetical spills (acrylonitrile, 625 barrels; and denatured ethanol, 857 barrels) were used to demonstrate CAFE's practical application. Most species in the 24-h SSD could be potentially impacted by acrylonitrile and denatured ethanol during the first 35 min and 15 h post spill, respectively, with concentrations falling below their HC5s (17 mg/L and 2676 mg/L) at 45 min and 60 h post spill, respectively. Comparisons of CAFE-based versus published HC5 values for 100 chemicals showed that nearly half of values were within a 2-fold difference, with a relatively small number of comparisons exceeding a 10-fold difference. The development of CAFE facilitates access to relevant environmental information, with potential uses likely expanding beyond those related to assessment of spills in aquatic environments. Environ Toxicol Chem 2016;35:1576-1586. © 2015 SETAC.

  6. Effect of Continuous Assessment on Learning Outcomes on Two Chemical Engineering Courses: Case Study

    Science.gov (United States)

    Tuunila, R.; Pulkkinen, M.

    2015-01-01

    In this paper, the effect of continuous assessment on the learning outcomes of two chemical engineering courses is studied over a several-year period. Average grades and passing percentages of courses after the final examination are reported and also student feedback on the courses is collected. The results indicate significantly better learning…

  7. Information resources for assessing health effects from chemical exposure: Challenges, priorities, and future issues

    Energy Technology Data Exchange (ETDEWEB)

    Seigel, S. [National Library of Medicine, Bethesda, MD (United States)

    1990-12-31

    Issues related to developing information resources for assessing the health effects from chemical exposure include the question of how to address the individual political issues relevant to identifying and determining the timeliness, scientific credibility, and completeness of such kinds of information resources. One of the important ways for agencies to share information is through connection tables. This type of software is presently being used to build information products for some DHHS agencies. One of the challenges will be to convince vendors of data of the importance of trying to make data files available to communities that need them. In the future, information processing will be conducted with neural networks, object-oriented database management systems, and fuzzy-set technologies, and meta analysis techniques.

  8. The Indigenous Cuminum Cyminum L. of Yazd Province: Chemical Assessment and Evaluation of its Antioxidant Effects

    Directory of Open Access Journals (Sweden)

    M Kalantar

    2011-09-01

    Full Text Available Introduction: Iran is one of the greatest and the most divergent resources of medicinal plants. Cuminum cyminum is one of the important and valuable medicinal plants of our country with such medical effects as anti-seizure, anti- epilepsy, stomach-strengthening, diuretic, anti-flatulence and maldigestion. The aim of this research is to assess the chemical components and antioxidant effects of the seed essence of this plant. Methods: The seed essence from southwest mountains of Behabad, Yazd was extracted by Clevenger apparatus, then segregation and recognition of components was performed by Gas Chromatography(GC and Gas Chromatography-Mass Spectrometry(GC-MS methods. The DPPH test was used for estimating antioxidant effects and Follin-Ciocalteu method was used for estimating the quantity of phenol compounds. This study was an applied research. Results: Components identification revealed that propanal (26.19%, 1-phenyl-1-butanol (16.49%, γ-Terpinene (13.04% and benzene methanol (25.4% had the highest percentage in the essence. The antioxidant test showed a high antioxidant effect with IC50 of 1.49 µg/mg and a high phenolic component percentage of about 162.62 mg/g. Conclusion: The propanal, the main component of seed essence, has a wide range of applications in industries and pharmacy. The result of this research showed a much higher antioxidant activity for native Cuminum Cyminum of Yazd province comparing the previous similar studies about this plant in other areas.

  9. Assessing the effects of adsorptive polymeric resin additions on fungal secondary metabolite chemical diversity

    Science.gov (United States)

    González-Menéndez, Víctor; Asensio, Francisco; Moreno, Catalina; de Pedro, Nuria; Monteiro, Maria Candida; de la Cruz, Mercedes; Vicente, Francisca; Bills, Gerald F.; Reyes, Fernando; Genilloud, Olga; Tormo, José R.

    2014-01-01

    Adsorptive polymeric resins have been occasionally described to enhance the production of specific secondary metabolites (SMs) of interest. Methods that induce the expression of new chemical entities in fungal fermentations may lead to the discovery of new bioactive molecules and should be addressed as possible tools for the creation of new microbial chemical libraries for drug lead discovery. Herein, we apply both biological activity and chemical evaluations to assess the use of adsorptive resins as tools for the differential expression of SMs in fungal strain sets. Data automation approaches were applied to ultra high performance liquid chromatography analysis of extracts to evaluate the general influence in generating new chemical entities or in changing the production of specific SMs by fungi grown in the presence of resins and different base media. PMID:25379340

  10. Spatial resolution of tip-enhanced Raman spectroscopy - DFT assessment of the chemical effect.

    Science.gov (United States)

    Latorre, Federico; Kupfer, Stephan; Bocklitz, Thomas; Kinzel, Daniel; Trautmann, Steffen; Gräfe, Stefanie; Deckert, Volker

    2016-05-21

    Experimental evidence of extremely high spatial resolution of tip-enhanced Raman scattering (TERS) has been recently demonstrated. Here, we present a full quantum chemical description (at the density functional level of theory) of the non-resonant chemical effects on the Raman spectrum of an adenine molecule mapped by a tip, modeled as a single silver atom or a small silver cluster. We show pronounced changes in the Raman pattern and its intensities depending on the conformation of the nanoparticle-substrate system, concluding that the spatial resolution of the chemical contribution of TERS can be in the sub-nm range.

  11. An improved probit method for assessment of domino effect to chemical process equipment caused by overpressure.

    Science.gov (United States)

    Mingguang, Zhang; Juncheng, Jiang

    2008-10-30

    Overpressure is one important cause of domino effect in accidents of chemical process equipments. Damage probability and relative threshold value are two necessary parameters in QRA of this phenomenon. Some simple models had been proposed based on scarce data or oversimplified assumption. Hence, more data about damage to chemical process equipments were gathered and analyzed, a quantitative relationship between damage probability and damage degrees of equipment was built, and reliable probit models were developed associated to specific category of chemical process equipments. Finally, the improvements of present models were evidenced through comparison with other models in literatures, taking into account such parameters: consistency between models and data, depth of quantitativeness in QRA.

  12. Assessment of chemicals in construction products

    DEFF Research Database (Denmark)

    Krogh, Hanne; Olsen, Stig Irving

    2000-01-01

    The building sector uses a lot of products (several thousands) and many of these contain chemicals, some of which have harmful effects on human and environmental health. Due to the restricted knowledge of data, the impacts of chemicals can be overlooked e.g. in eco-profiles of building elements....... The reasons for that are lacks of product-specific emissions by manufacturing of chemical products, e.g. waterproofing systems and sealants. Besides, most LCA-models do not include assessments of emissions in working environment, in indoor environment or from disposal processes. It was therefore...... in the project Assessment of Chemicals in Construction Products decided to adapt an existing score method for assessing the chemicals. As the European countries had agreed on a score Method for Risk Ranking chemicals (EURAM), it was decided to use this method to assess chemicals in construction products for two...

  13. Model-based experimental design for assessing effects of mixtures of chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Baas, Jan, E-mail: jan.baas@falw.vu.n [Vrije Universiteit of Amsterdam, Dept of Theoretical Biology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Stefanowicz, Anna M., E-mail: anna.stefanowicz@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Klimek, Beata, E-mail: beata.klimek@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Laskowski, Ryszard, E-mail: ryszard.laskowski@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Kooijman, Sebastiaan A.L.M., E-mail: bas@bio.vu.n [Vrije Universiteit of Amsterdam, Dept of Theoretical Biology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

    2010-01-15

    We exposed flour beetles (Tribolium castaneum) to a mixture of four poly aromatic hydrocarbons (PAHs). The experimental setup was chosen such that the emphasis was on assessing partial effects. We interpreted the effects of the mixture by a process-based model, with a threshold concentration for effects on survival. The behavior of the threshold concentration was one of the key features of this research. We showed that the threshold concentration is shared by toxicants with the same mode of action, which gives a mechanistic explanation for the observation that toxic effects in mixtures may occur in concentration ranges where the individual components do not show effects. Our approach gives reliable predictions of partial effects on survival and allows for a reduction of experimental effort in assessing effects of mixtures, extrapolations to other mixtures, other points in time, or in a wider perspective to other organisms. - We show a mechanistic approach to assess effects of mixtures in low concentrations.

  14. Biological effects of anthropogenic chemical stress: Tools for the assessment of ecosystem health (BEAST)

    DEFF Research Database (Denmark)

    Lehtonen, Kari K.; Sundelin, Brita; Lang, Thomas;

    : Tools for the Assessment of Ecosystem Health, 2009-2011), which is part of the Baltic Sea BONUS+ Programme funded jointly by national funding agencies and FP7 ERA-NET+ of the European Commission. The BEAST project consists of three workpackages (WP) with the following main tasks: WP1- Field studies...... and experiments in selected sub-regions of the Baltic Sea, WP2 - Application and validation of methods in monitoring and assessment in the Baltic Sea, and WP3 - Developing tools for ecosystem health assessment in the Baltic Sea. BEAST research activities are focused in the sub-regions of Gulf of Bothnia, Gulf...... of Finland, Gulf of Riga, Gulf of Gdansk and the Belt Sea, most of which are characterised by scarce data on biological effects of hazardous substances. The data acquired will be combined with previous data (e.g. national monitoring activities, case studies, EU BEEP project) to reach the goals of WP2 and WP3...

  15. [Risk assessment of chemical agents].

    Science.gov (United States)

    Cottica, Danilo; Grignani, Elena; Bartolucci, Giovanni Battista

    2011-01-01

    The risk assessment of chemical agents is a well known and applied process carried out by Industrial Hygienists and Occupational Physicians based on exposure evaluation. The application of REACH (CE 1907/2006), CLP (CE 1272/2008) and SDS (UE 453/2010) introduces some changes and instruments to carry out the occupational exposure assessment, like new classification of substances, Exposure Scenario, suggested control measures that the Industrial Hygienist and the Occupational Physician must evaluate. If there is not a similar Exposure Scenario to apply a new risk assessment must carried out also by recommended software (ECETOC Targeted Risk Assessment; Easy to use workplace EMKG; Stoffenmanager). Looking at the relevance of the control measures and evaluation of Exposure Scenario we report the flowchart of risk assessment and management by the Method of Organisational Congruencies carried out with the Prevention and Protection Service and Occupational Physician Office of the Health Service of the Azienda Provinciale of Trento.

  16. Information resources for assessing health effects from chemical exposure: Office of pesticides programs

    Energy Technology Data Exchange (ETDEWEB)

    Fenner-Crisp, P. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The US Environmental Protection Agency (EPA) Office of Pesticide Programs is trying to develop a complete picture of a chemical`s toxicity and exposure profile. It is also important to share information in the office`s files because of pesticides, particularly as a consequence of agricultural use, find their way into places not necessarily intended.

  17. A Tutorial for Analysing the Cost-effectiveness of Alternative Methods for Assessing Chemical Toxicology: The Case of Acute Oral Toxicity Prediction

    NARCIS (Netherlands)

    Norlen, H.; Worth, A.P.; Gabbert, S.G.M.

    2014-01-01

    Compared with traditional animal methods for toxicity testing, in vitro and in silico methods are widely considered to permit a more cost-effective assessment of chemicals. However, how to assess the cost-effectiveness of alternative methods has remained unclear. This paper offers a user-oriented tu

  18. A SEM Model in Assessing the Effect of Convergent, Divergent and Logical Thinking on Students' Understanding of Chemical Phenomena

    Science.gov (United States)

    Stamovlasis, D.; Kypraios, N.; Papageorgiou, G.

    2015-01-01

    In this study, structural equation modeling (SEM) is applied to an instrument assessing students' understanding of chemical change. The instrument comprised items on understanding the structure of substances, chemical changes and their interpretation. The structural relationships among particular groups of items are investigated and analyzed using…

  19. Transgenic (cyp19a1b-GFP) zebrafish embryos as a tool for assessing combined effects of oestrogenic chemicals.

    Science.gov (United States)

    Petersen, Karina; Fetter, Eva; Kah, Olivier; Brion, François; Scholz, Stefan; Tollefsen, Knut Erik

    2013-08-15

    Endocrine disrupting chemicals and especially oestrogen receptor (ER) agonists have been extensively studied over the years due to their potential effects on sexual development and reproduction in vertebrates, notably fish. As ER agonists can exist as complex mixtures in the aquatic environment, evaluating the impact of combined exposure on oestrogenic effects has become increasingly important. Use of predictive models such as concentration addition (CA) and independent action (IA) has allowed assessment of combined estrogenic effects of complex multi-compound mixtures of ER agonists in various fish in vitro and in vivo experimental models. The present work makes use of a transgenic zebrafish strain, tg(cyp19a1b-GFP), which expresses the green fluorescent protein (GFP) under the control of the cyp19a1b (brain aromatase or aromatase B) gene to determine the oestrogenic potency of ER agonists alone or in mixtures. In these studies, tg(cyp19a1b-GFP) zebrafish embryos were exposed for four days (from one to five days post fertilization) to five different oestrogenic chemicals; 17α-ethinylestradiol (EE2), 17β-estradiol (E2), estrone (E1), bisphenol A (BPA) and 4-tert-octylphenol (OP), and three mixtures of up to four of these compounds. The mixture of BPA, OP and E2 was also tested with primary cultures of rainbow trout hepatocytes by analysing the ER-mediated induction of the oestrogenic biomarker vitellogenin in order to compare the performance of the two methods for assessing oestrogenic effects of complex mixtures. The three tested mixtures were predominantly acting in an additive manner on the expression of GFP. Additivity was indicated by the overlap of the 95% confidence interval of the concentration response curves for the observed data with the CA and IA prediction models, and model deviation ratios within a factor of two for a majority of the mixture concentrations. However, minor deviations determined as more than additive effects for the mixture of EE2, E1

  20. Assessing ecorelevance of emerging chemicals in sediments

    DEFF Research Database (Denmark)

    Forbes, Valery E.; Selck, Henriette; Salvito, D.

    2007-01-01

    effects measured on individuals can be extrapolated to the population level. The consequences of these studies and their impact on the assessment of risk will be discussed. An important message is that not all organismal or sub-organismal responses that are currently measured are relevant for protecting......Environmental monitoring of the Great Lakes and elsewhere has detected the presence of a wide variety of chemicals which has raised concern that these chemicals pose risks to resident species. Sediments are of particular interest due to their tendency to accumulate hydrophobic and persistent...

  1. Chemical shift imaging at 3 Tesla: effect of echo time on assessing bone marrow abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Del Grande, F. [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Ospedale Regionale di Lugano, Servizio di Radiologia, Lugano, TI (Switzerland); Subhawong, Ty [University of Miami Miller School of Medicine, Department of Radiology, Miami, FL (United States); Flammang, A. [Siemens Medical Solutions USA, Inc., Malvern, PA (United States); Fayad, L.M. [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States)

    2014-08-15

    Our purpose is to test the effect of varied in-phase (IP) and opposed-phase (OP) sequence order on characterizing marrow signal changes at 3T. The study was HIPAA compliant and IRB approved. Informed consent was waived. At 3T, IP and OP sequences were acquired in three patients with biopsy-proven osteosarcomas, using two methods: approach 1 (OP acquisition before IP acquisition) and approach 2 (OP after IP). Signal intensity (SI) measurements in 12 locations of biopsy-proven osteosarcoma and in six locations with normal bone marrow were performed independently by two experienced musculoskeletal radiologists. The signal intensity ratio (SIR) was measured within the marrow where there was T1 signal lower than skeletal muscle. A SIR < 20 % on the OP compared with IP imaging was considered positive for marrow replacement, while SIR > = 20 % was considered negative. Interobserver agreement was measured by the Lin concordance correlation coefficient (CCC). In 75 % (18/24) of locations within the biopsy-proven tumors, the SIR was >20 % (SI drop more than 20 % in OP compared to IP) using approach 2 and in 100 % (24/24) of the locations the SIR was <20 % (SI drop less than 20 % in OP compared to IP) using approach 1, indicating a high percentage of false-negative results by approach 2, and no false-negative results with approach 1. There was good agreement between observer measurement (CCC = 0.96). At 3T, the OP sequence should be acquired prior to the IP sequence, because susceptibility artifacts on a later-acquired OP sequence may lead to an erroneous interpretation of marrow signal abnormalities. (orig.)

  2. Chemical mixtures: considering the evolution of toxicology and chemical assessment.

    Science.gov (United States)

    Monosson, Emily

    2005-04-01

    The assessment of chemical mixtures is a complex topic for toxicologists, regulators, and the public. In this article the linkage between the science of toxicology and the needs of governmental regulatory agencies in the United States is explored through an overview of environmental regulations enacted over the past century and a brief history of modern toxicology. One of the goals of this overview is to encourage both regulators and scientists to consider the benefits and limitations of this science-regulatory relationship as they tackle existing issues such as chemical mixtures. It is clear that a) over the past 100 years chemical regulation and toxicologic research, have in large part, shared a common emphasis on characterization and regulation of individual chemicals. But chemical mixtures have been, and continue to be, evaluated at hazardous waste sites around the United States. For this reason the current U.S. Environmental Protection Agency guidelines for chemical mixtures assessment are also reviewed. These guidelines highlight the current practice of mixtures assessment, which relies primarily on the existing single-chemical database. It is also clear that b) the science and assessment of chemical mixtures are moving forward through the combined efforts of regulatory agencies and scientists from a broad range of disciplines, including toxicology. Because toxicology is at this exciting crossroads, particular attention should be paid to the forces (e.g., public demands, regulatory needs, funding, academic interests) that both promote and limit the growth of this expanding discipline.

  3. Hazard assessment of chemical contaminants in soil.

    Science.gov (United States)

    Poels, C L; Veerkamp, W

    1992-12-01

    Disposal practices, accidental spills, leakages and local aerial deposition occurring in the past have led to local soil pollution in many cases. Especially in situations where people live on or nearby such locations this has created concern about possible adverse effects on human health. A stepped approach to the hazard assessment of polluted soil, as developed by a Task Force from the European Chemical Industry Ecology and Toxicology Centre (ECETOC), is described. In an early phase in the assessment process the potential exposure of humans is estimated. The Human Exposure to Soil Pollutants (HESP) model can be applied for this purpose. The model calculates the total exposure of adults and children resulting from pollutants present in soil, via 10 different exposure routes. The estimated exposure can be used to indicate the potential significant exposure routes and to carry out a preliminary hazard assessment. The model is also able to predict pollutant concentrations in soil which do not exceed accepted maximum exposure levels for humans in both standardised and site specific situations. The stepped approach is cost-effective and provides an objective basis for decisions and priority setting.

  4. Predicted no effect concentration derivation as a significant source of variability in environmental hazard assessments of chemicals in aquatic systems: an international analysis.

    Science.gov (United States)

    Hahn, Thorsten; Diamond, Jerry; Dobson, Stuart; Howe, Paul; Kielhorn, Janet; Koennecker, Gustav; Lee-Steere, Chris; Mangelsdorf, Inge; Schneider, Uwe; Sugaya, Yoshio; Taylor, Ken; Dam, Rick Van; Stauber, Jenny L

    2014-01-01

    Environmental hazard assessments for chemicals are carried out to define an environmentally "safe" level at which, theoretically, the chemical will not negatively affect any exposed biota. Despite this common goal, the methodologies in use are very diverse across different countries and jurisdictions. This becomes particularly obvious when international scientists work together on documents with global scope, e.g., in the World Health Organization (WHO) International Program on Chemical Safety. In this article, we present a study that describes the extent of such variability and analyze the reasons that lead to different outcomes in deriving a "safe level" (termed the predicted no effect concentration [PNEC] throughout this article). For this purpose, we chose 5 chemicals to represent well-known substances for which sufficient high-quality aquatic effects data were available: ethylene glycol, trichloroethylene, nonylphenol, hexachlorobenzene, and copper (Cu). From these data, 2 data sets for each chemical were compiled: the full data set, that contained all information from selected peer-review sources, and the base data set, a subsample of the full set simulating limited data. Scientists from the European Union (EU), United States, Canada, Japan, and Australia independently carried out hazard assessments for each of these chemicals using the same data sets. Their reasoning for key study selection, use of assessment factors, or use of probabilistic methods was comprehensively documented. The observed variation in the PNECs for all chemicals was up to 3 orders of magnitude, and this was not simply due to obvious factors such as the size of the data set or the methodology used. Rather, this was due to individual decisions of the assessors within the scope of the methodology used, especially key study selection, acute versus chronic definitions, and size of assessment factors. Awareness of these factors, together with transparency of the decision-making process, would

  5. 膜的化学清洗及综合效应评价%MEMBRANE CHEMICAL CLEANING AND ASSESSMENT OF ITS COMPREHENSIVE EFFECTS

    Institute of Scientific and Technical Information of China (English)

    聂晶; 王龙; 孙理密; 王明晖

    2012-01-01

    The type and cause of membrane fouling were summarized in this paper, mechanism and cleaning agents species of chemical cleaning were also introduced, an assessment method of chemical cleaning comprehensive effects was proposed by analytic hierarchies process, the method involved effects .costs and environmental impact of chemical cleaning; then a microfiltration membrane system was taken for example which was used for sewage treatment, empirical research of two options was carried out, the results showed that, Option Ⅱ was better than Option Ⅰ. The method performed good operationality and the assessment results can be used for opting reasonable membrane chemical cleaning option.%概述了膜污染的类型与成因、化学清洗机理及清洗剂的类型,从清洗效果、清洗成本、环境影响3方面,利用层次分析法构建了膜化学清洗综合效应的评价方法;并以某生活污水处理系统的微滤膜为例,进行了两个方案的实证研究,结果表明,方案2要优于方案1.该评价方法可操作性强,评价结果能为选择科学合理的膜化学清洗方案提供依据.

  6. The effectiveness of spent coffee grounds and its biochar on the amelioration of heavy metals-contaminated water and soil using chemical and biological assessments.

    Science.gov (United States)

    Kim, Min-Suk; Min, Hyun-Gi; Koo, Namin; Park, Jeongsik; Lee, Sang-Hwan; Bak, Gwan-In; Kim, Jeong-Gyu

    2014-12-15

    Spent coffee grounds (SCG) and charred spent coffee grounds (SCG-char) have been widely used to adsorb or to amend heavy metals that contaminate water or soil and their success is usually assessed by chemical analysis. In this work, the effects of SCG and SCG-char on metal-contaminated water and soil were evaluated using chemical and biological assessments; a phytotoxicity test using bok choy (Brassica campestris L. ssp. chinensis Jusl.) was conducted for the biological assessment. When SCG and SCG-char were applied to acid mine drainage, the heavy metal concentrations were decreased and the pH was increased. However, for SCG, the phytotoxicity increased because a massive amount of dissolved organic carbon was released from SCG. In contrast, SCG-char did not exhibit this phenomenon because any easily released organic matter was removed during pyrolysis. While the bioavailable heavy metal content decreased in soils treated with SCG or SCG-char, the phytotoxicity only rose after SCG treatment. According to our statistical methodology, bioavailable Pb, Cu and As, as well as the electrical conductivity representing an increase in organic content, affected the phytotoxicity of soil. Therefore, applying SCG during environment remediation requires careful biological assessments and evaluations of the efficiency of this remediation technology.

  7. The applicability of chemical alternatives assessment for engineered nanomaterials.

    Science.gov (United States)

    Hjorth, Rune; Hansen, Steffen Foss; Jacobs, Molly; Tickner, Joel; Ellenbecker, Michael; Baun, Anders

    2017-01-01

    The use of alternatives assessment to substitute hazardous chemicals with inherently safer options is gaining momentum worldwide as a legislative and corporate strategy to minimize consumer, occupational, and environmental risks. Engineered nanomaterials represent an interesting case for alternatives assessment approaches, because they can be considered both emerging "chemicals" of concern, as well as potentially safer alternatives to hazardous chemicals. However, comparing the hazards of nanomaterials to traditional chemicals or to other nanomaterials is challenging, and critical elements in chemical hazard and exposure assessment may have to be fundamentally altered to sufficiently address nanomaterials. The aim of this paper is to assess the overall applicability of alternatives assessment methods for nanomaterials and to outline recommendations to enhance their use in this context. The present paper focuses on the adaptability of existing hazard and exposure assessment approaches to engineered nanomaterials as well as strategies to design inherently safer nanomaterials. We argue that alternatives assessment for nanomaterials is complicated by the sheer number of nanomaterials possible. As a result, the inclusion of new data tools that can efficiently and effectively evaluate nanomaterials as substitutes is needed to strengthen the alternatives assessment process. However, we conclude that with additional tools to enhance traditional hazard and exposure assessment modules of alternatives assessment, such as the use of mechanistic toxicity screens and control banding tools, alternatives assessment can be adapted to evaluate engineered nanomaterials as potential substitutes for chemicals of concern and to ensure safer nanomaterials are incorporated in the design of new products. Integr Environ Assess Manag 2017;13:177-187. © 2016 SETAC.

  8. Dangerous chemical substances – Tools supporting occupational risk assessment

    OpenAIRE

    Elżbieta Dobrzyńska; Małgorzata Pośniak

    2014-01-01

    The assessment of risk associated with exposure to chemicals in the work environment is a task that still poses a lot of difficulties for the employers. At the same time the probability of adverse health effects faced by an employee as a result of such risks, and the related employer’s material losses should motivate employers to seek effective solutions aimed at assessing the risks and controling them to an acceptable level by the application of appropriate preventive measures. The paper pre...

  9. Endocrine disrupting chemicals and other substances of concern in food contact materials: an updated review of exposure, effect and risk assessment.

    Science.gov (United States)

    Muncke, Jane

    2011-10-01

    Food contact materials (FCM) are an underestimated source of chemical food contaminants and a potentially relevant route of human exposure to endocrine disrupting chemicals (EDCs). Quantifying the exposure of the general population to substances from FCM relies on estimates of food consumption and leaching into food. Recent studies using polycarbonate plastics show that food simulants do not always predict worst-case leaching of bisphenol A, a common FCM substance. Also, exposure of children to FCM substances is not always realistically predicted using the common conventions and thus possibly misjudged. Further, the exposure of the whole population to substances leaching into dry foods is underestimated. Consumers are exposed to low levels of substances from FCM across their entire lives. Effects of these compounds currently are assessed with a focus on mutagenicity and genotoxicity. This approach however neglects integrating recent new toxicological findings, like endocrine disruption, mixture toxicity, and developmental toxicity. According to these new toxicology paradigms women of childbearing age and during pregnancy are a new sensitive population group requiring more attention. Furthermore, in overweight and obese persons a change in the metabolism of xenobiotics is observed, possibly implying that this group of consumers is insufficiently protected by current risk assessment practice. Innovations in FCM risk assessment should therefore include routine testing for EDCs and an assessment of the whole migrate toxicity of a food packaging, taking into account all sensitive population groups. In this article I focus on recent issues of interest concerning either exposure to or effects of FCM-related substances. Further, I review the use of benzophenones and organotins, two groups of known or suspected EDCs, in FCM authorized in the US and EU.

  10. Potential impacts on groundwater resources of deep CO2 storage: natural analogues for assessing potential chemical effects

    Science.gov (United States)

    Lions, J.; Gale, I.; May, F.; Nygaard, E.; Ruetters, H.; Beaubien, S.; Sohrabi, M.; Hatzignatiou, D. G.; CO2GeoNet Members involved in the present study Team

    2011-12-01

    Carbon dioxide Capture and Storage (CCS) is considered as one of the promising options for reducing atmospheric emissions of CO2 related to human activities. One of the main concerns associated with the geological storage of CO2 is that the CO2 may leak from the intended storage formation, migrate to the near-surface environment and, eventually, escape from the ground. This is a concern because such leakage may affect aquifers overlying the storage site and containing freshwater that may be used for drinking, industry and agriculture. The IEA Greenhouse Gas R&D Programme (IEAGHG) recently commissioned the CO2GeoNet Association to undertake a review of published and unpublished literature on this topic with the aim of summarizing 'state of the art' knowledge and identifying knowledge gaps and research priorities in this field. Work carried out by various CO2GeoNet members was also used in this study. This study identifies possible areas of conflict by combining available datasets to map the global and regional superposition of deep saline formations (DSF) suitable for CO2 storage and overlying fresh groundwater resources. A scenario classification is developed for the various geological settings where conflict could occur. The study proposes two approaches to address the potential impact mechanisms of CO2 storage projects on the hydrodynamics and chemistry of shallow groundwater. The first classifies and synthesizes changes of water quality observed in natural/industrial analogues and in laboratory experiments. The second reviews hydrodynamic and geochemical models, including coupled multiphase flow and reactive transport. Various models are discussed in terms of their advantages and limitations, with conclusions on possible impacts on groundwater resources. Possible mitigation options to stop or control CO2 leakage are assessed. The effect of CO2 pressure in the host DSF and the potential effects on shallow aquifers are also examined. The study provides a review of

  11. Animal-Free Chemical Safety Assessment

    Directory of Open Access Journals (Sweden)

    George D Loizou

    2016-07-01

    Full Text Available The exponential growth of the Internet of Things and the global popularity and remarkable decline in cost of the mobile phone is driving the digital transformation of medical practice. The rapidly maturing digital, nonmedical world of mobile (wireless devices, cloud computing and social networking is coalescing with the emerging digital medical world of omics data, biosensors and advanced imaging which offers the increasingly realistic prospect of personalized medicine. Described as a potential seismic shift from the current healthcare model to a wellness paradigm that is predictive, preventative, personalized and participatory, this change is based on the development of increasingly sophisticated biosensors which can track and measure key biochemical variables in people. Additional key drivers in this shift are metabolomic and proteomic signatures, which are increasingly being reported as pre-symptomatic, diagnostic and prognostic of toxicity and disease. These advancements also have profound implications for toxicological evaluation and safety assessment of pharmaceuticals and environmental chemicals. An approach based primarily on human in vivo and high-throughput in vitro human cell-line data is a distinct possibility. This would transform current chemical safety assessment practise which operates in a human data poor to a human data rich environment. This could also lead to a seismic shift from the current animal-based to an animal-free chemical safety assessment paradigm.

  12. Animal-Free Chemical Safety Assessment.

    Science.gov (United States)

    Loizou, George D

    2016-01-01

    The exponential growth of the Internet of Things and the global popularity and remarkable decline in cost of the mobile phone is driving the digital transformation of medical practice. The rapidly maturing digital, non-medical world of mobile (wireless) devices, cloud computing and social networking is coalescing with the emerging digital medical world of omics data, biosensors and advanced imaging which offers the increasingly realistic prospect of personalized medicine. Described as a potential "seismic" shift from the current "healthcare" model to a "wellness" paradigm that is predictive, preventative, personalized and participatory, this change is based on the development of increasingly sophisticated biosensors which can track and measure key biochemical variables in people. Additional key drivers in this shift are metabolomic and proteomic signatures, which are increasingly being reported as pre-symptomatic, diagnostic and prognostic of toxicity and disease. These advancements also have profound implications for toxicological evaluation and safety assessment of pharmaceuticals and environmental chemicals. An approach based primarily on human in vivo and high-throughput in vitro human cell-line data is a distinct possibility. This would transform current chemical safety assessment practice which operates in a human "data poor" to a human "data rich" environment. This could also lead to a seismic shift from the current animal-based to an animal-free chemical safety assessment paradigm.

  13. Integrated Assessment Systems for Chemical Warfare Material

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Snyder; D. A. Verrill; G. L. Thinnes; K. D. Watts; R. J. McMorland

    1999-05-27

    The US Army must respond to a variety of situations involving suspect discovered, recovered, stored, and buried chemical warfare materiel (CWM). In some cases, the identity of the fill materiel and the status of the fusing and firing train cannot be visually determined due to aging of the container, or because the item is contained in an over-pack. In these cases, non-intrusive assessments are required to provide information to allow safe handling, storage, and disposal of the materiel. This paper will provide an overview of the integrated mobile and facility-based CWM assessment system prototypes that have been, and are being developed, at the Idaho National Engineering and Environmental Laboratory (INEEL) for the US Army Non-Stockpile Chemical Materiel Project. In addition, this paper will discuss advanced sensors being developed to enhance the capability of the existing and future assessment systems. The Phase I Mobile Munitions Assessment System (MMAS) is currently being used by the Army's Technical Escort Unit (TEU) at Dugway Proving Ground, Utah. This system includes equipment for non-intrusively identifying the munitions fill materiel and for assessing the condition and stability of the fuzes, firing trains, and other potential safety hazards. The system provides a self-contained, integrated command post including an on-board computer system, communications equipment, video and photographic equipment, weather monitoring equipment, and miscellaneous safety-related equipment. The Phase II MMAS is currently being tested and qualified for use by the INEEL and the US Army. The Phase II system contains several new assessment systems that significantly enhance the ability to assess CWM. A facility-based munitions assessment system prototype is being developed for the assessment of CWM stored in igloos at Pine Bluff Arsenal, Arkansas. This system is currently in the design and fabrication stages. Numerous CWM advanced sensors are being developed and tested, and

  14. Chemical reactivity assessments in R&D.

    Science.gov (United States)

    Leggett, David

    2004-11-11

    The evaluation of reactive chemical hazards at the pilot and manufacturing scale, using laboratory testing, is increasingly used and has been well documented. However, reactive chemical hazard evaluation at the R&D scale presents special challenges. The typical hazard testing program requires a significant amount of sample, often takes time (>3 days) to complete, and is can be quite costly. On the other hand, the synthesis of new molecules in the R&D environment often produces only a few grams, occurs quickly (R&D stage of product development to define the critical limits of temperature, pressure, concentration, and safe dosing rates of processes it is possible to identify the potential hazards of the planned synthesis. This paper describes a staged approach for chemical reactivity hazard evaluation and assessment applicable to an R&D environment. We will describe these initial phases of the R&D hazard evaluation process that rely on only data that can be obtained from the open literature. We will also indicate how the need for additional assessments can be determined from this initial hazard review.

  15. Assessing the effectiveness of regulatory controls on farm pollution using chemical and biological indices of water quality and pollution statistics.

    Science.gov (United States)

    Foy, R H; Lennox, S D; Smith, R V

    2001-08-01

    Water quality was measured in 42 streams in the Colebrooke and Upper Bann catchments in Northern Ireland over the period 1990-1998. Despite ongoing pollution control measures, biological water quality, as determined by the invertebrate average score per taxon (ASPT) index, did not improve and there was no appreciable decline in recorded farm pollution incidents. However, the lack of decline in pollution incidents could reflect changes in detection policy, as a greater proportion of incidents were recorded from less polluting discharges such as farm-yard runoff. In contrast, there was an improvement during 1997 and 1998 in annual chemical water quality classification based on exceedence values (90th percentiles) for dissolved oxygen, ammonium and BOD concentrations. In 1998, 11.9% of streams were severely polluted compared to 26.2% in 1990, while the proportion classed as of salmonid water quality, increased from 40.5% in 1990 to 59.6% in 1998. Although water quality in 1996 did not improve relative to 1990 values, there was a notable increasing trend from 1990 in the numbers of samples taken during the summer which had good water quality with low ammonium ( 70% sat). The trend for samples with low BOD (<4 mgl(-1)) was more erratic, but an improvement was apparent from 1994. These improvements in chemical water quality suggest that point-source farm pollution declined after 1990. The fact that this was not reflected in stream biology may reflect the limited time scale for biological recovery. An important factor preventing biological recovery may be the high pollution capacity of manures and silage effluent, so that even reduced numbers of farm pollution incidents can severely perturb stream ecosystems. The intractable nature of farm pollution suggests that there is a need to consider an interactive approach to problem resolution involving both farmers and regulators.

  16. Transcriptomic-based effects monitoring for endocrine active chemicals: Assessing relative contribution of treated wastewater to downstream pollution

    Science.gov (United States)

    The present study investigated whether combining of targeted analytical chemistry methods with unsupervised, data-rich methodologies (i.e. transcriptomics) can be utilized to evaluate relative contributions of wastewater treatment plant (WWTP) effluents to biological effects. The...

  17. Simplified fate, exposure and effect modelling of chemical compounds in the case of lacking complete assessment data sets

    DEFF Research Database (Denmark)

    Birkved, Morten; Heijungs, R; Olsen, Stig Irving

    2004-01-01

    .g. in terms of how the input parameters enter the regression equation. In the absence of a final OMNIITOX BM a model of similar complexity USES-LCA, has been used as surrogate BM. We have applied partial least square of latent structure regression (PLSR) and combined insights from this with knowledge on data......Within the EU 5th framework OMNIITOX project a simple base model (SBM) is currently being developed to calculate characterisation factors for life cycle impact assessment of toxic releases. This SBM will be derived from a multi-media base model (BM) using statistical techniques combined...... availability limitations to select key parameters that explain much of the variance and at the same time are relatively easily available. Further, PLSR was used to derive linear SBM models. In further investigations multiple linear regression (MLR) will be used to derive predictive equations for SBM...

  18. Assessing Terrorist Motivations for Attacking Critical "Chemical" Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, G; Bale, J; Moran, K

    2004-12-14

    facilities to date; and (4) the refinement of the DECIDe--the Determinants Effecting Critical Infrastructure Decisions--analytical framework to make the factors and dynamics identified by the study more ''usable'' in future efforts to assess terrorist intentions to target chemical-related infrastructure.

  19. Critical issues in benzene toxicity and metabolism: The effect of interactions with other organic chemicals on risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Medinsky, M.A.; Schlosser, P.M.; Bond, J.A. [Chemical Industry Institute of Toxicology, Research Triangle Park, NC (United States)

    1994-11-01

    Benzene, an important industrial solvent, is also present in unleaded gasoline and cigarette smoke. The hematotoxic effects of benzene are well documented and include aplastic anemia and pancytopenia. Some individuals exposed repeatedly to cytotoxic concentrations of benzene develop acute myeloblastic anemia. It has been hypothesized that metabolism of benzene is required for its toxicity, although administration of no single benzene metabolite duplicates the toxicity of benzene. Several investigators have demonstrated that a combination of metabolites (hydroquinone and phenol, for example) is necessary to duplicate the hematotoxic effect of benzene. Enzymes implicated in the metabolic activation of benzene and its metabolites include the cytochrome P450 monooxygenases and myeloperoxidase. Since benzene and its hydroxylated metabolites (phenol, hydroquinone, and catechol) are substrates for the same cytochrome P450 enzymes, competitive interactions among the metabolites are possible. In vivo data on metabolite formation by mice exposed to various benzene concentrations are consistent with competitive inhibition of phenol oxidation by benzene. Other organic molecules that are substrates for cytochrome P450 can inhibit the metabolism of benzene. For example, toluene has been shown to inhibit the oxidation of benzene in a noncompetitive manner. Enzyme inducers, such as ethanol, can alter the target tissue dosimetry of benzene metabolites by inducing enzymes responsible for oxidation reactions involved in benzene metabolism. 24 refs., 6 figs., 2 tabs.

  20. Chemical variations in the Cerro de Mercado (Durango, Mexico) fluorapatite: Assessing the effect of heterogeneity on a geochronologic standard.

    Science.gov (United States)

    Boyce, J. W.; Hodges, K. V.

    2001-12-01

    Despite the lack of an official pronouncement, the fluorapatite of Cerro de Mercado, Durango, Mexico has become the de facto standard for (U-Th)/He geochronology. In addition to being relatively inclusion-free and easily obtained, these crystals are commonly in excess of 5mm in diameter, permitting the removal of the outer skin of the crystal, theoretically eliminating the alpha-ejection correction. However, bulk analyses of the Durango fluorapatite indicate a substantial variation in U and Th concentrations from aliquot to aliquot (167-238 ppm Th; 9.7-12.3 ppm U, [1]). If similar variations were to occur on the sub-grain scale, small fragments of single crystals could contain helium excesses or deficiencies due to alpha-ejection exchange between zones with varying parent element content. We have performed a series of experiments to quantify the intra-grain variation in U and Th, in order to model the effect of this variation on ages determined on Durango fluorapatite. X-ray maps show concentric zonation in U and Th, with similar, but more apparently pronounced zonation in Si and Cl. Preliminary laser-ablation ICPMS data indicate, not surprisingly, that intra-grain variations in U and Th concentrations obtained by analysis of ~35 μ m spots are larger than that which had been previously obtained by bulk analytical techniques (with overall concentrations greater than for bulk analyses). Thus far, analyses yield U concentrations varying from 11 to 16 ppm, and Th concentrations ranging from 220 to 340 ppm. Modeling underway suggests that parent element variations on the order of 50%, such as those observed, and the resulting differential alpha-exchange could lead to several percent error in age, for ~100 μ m fragments. The effect scales inversely with fragment size, with 300 μ m fragments (roughly the size of a large, single grain analysis) having only ~1% error. This may offer an explanation for the previously observed inability to reproduce ages for the Durango

  1. Hazard and risk assessment of teratogenic chemicals under REACH.

    Science.gov (United States)

    Prutner, Wiebke

    2013-01-01

    In 2007, a new European chemicals legislation was implemented: Regulation (EC) No. 1907/2006, also known as "REACH." It obliges companies to take the main responsibility for the valid information on the safe use of the chemicals they manufacture and/or place on the European market. So they must, for example, register their chemicals at the European Chemicals Agency (ECHA) and submit extensive substance-related registration dossiers containing information on the substances' intrinsic hazardous properties and documentation of their risk assessment. REACH regulates the registration and evaluation process as well as the authorization and restriction procedure. In addition, classification, labeling, and packaging of chemicals apply in accordance with Regulation (EC) No. 1272/2008 ("CLP Regulation"). It implements almost completely the provisions of the United Nations Globally Harmonised System of Classification and Labelling of Chemicals (UN GHS) into European legislation and will fully replace the Dangerous Substances Directive (67/548/EEC) and the Dangerous Preparations Directive (1999/45/EC) by 2015. According to both the old and the new classification system, teratogenic chemicals are classified as developmental toxicants, with developmental toxicity falling within the hazard class of reproductive toxicity. REACH as well as the CLP Regulation provide several procedures in which reproductive toxicants take a special position because their harmful effects are considered particularly serious. Teratogenic substances are not explicitly named by these legal texts but, as they constitute as developmental toxicants a hazard differentiation of reproductive toxicity, they are implicitly always included by the provisions.

  2. Health effects of risk-assessment categories

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, C.F.; Rybicka, K.; Knutson, A.; Morris, S.C.

    1983-10-01

    Environmental and occupational health effects associated with exposures to various chemicals are a subject of increasing concern. One recently developed methodology for assessing the health impacts of various chemical compounds involves the classification of similar chemicals into risk-assessment categories (RACs). This report reviews documented human health effects for a broad range of pollutants, classified by RACs. It complements other studies that have estimated human health effects by RAC based on analysis and extrapolation of data from animal research.

  3. Clinical Considerations in the Assessment of Adolescent Chemical Dependency.

    Science.gov (United States)

    Winters, Ken

    1990-01-01

    Discusses relevant research findings of clinical assessment of adolescent chemical dependency so that service providers can better address these concerns. Three major issues are discussed: the definition of adolescent chemical dependency, clinical domains of assessment (chemical use problem severity, precipitating and perpetuating risk factors,…

  4. Overview of international programmes on the assessment of existing chemicals

    NARCIS (Netherlands)

    Wezel AP van; CSR

    1999-01-01

    This overview presents the major international programmes in which assessment of chemicals takes place. The appendix lists the chemicals assessed in the various programmes and sites the planning for the coming years. The overlap with the Dutch policy on chemicals is also overviewed.

  5. Dangerous chemical substances – Tools supporting occupational risk assessment

    Directory of Open Access Journals (Sweden)

    Elżbieta Dobrzyńska

    2014-10-01

    Full Text Available The assessment of risk associated with exposure to chemicals in the work environment is a task that still poses a lot of difficulties for the employers. At the same time the probability of adverse health effects faced by an employee as a result of such risks, and the related employer’s material losses should motivate employers to seek effective solutions aimed at assessing the risks and controling them to an acceptable level by the application of appropriate preventive measures. The paper presents examples of tools to assist the employer in the risk assessment associated with the presence of chemical agents in the workplace. Examples of guides, manuals, checklists and various interactive tools, developed in Poland and other European Union (EU countries, as well as in countries outside the EU and international organizations are described. These tools have been developed to meet the current requirements of the law and allow a rough estimation of chemical risk and based on these estimates take further steps to improve working conditions and safety. Med Pr 2014;65(5:683–692

  6. The applicability of chemical alternatives assessment for engineered nanomaterials

    DEFF Research Database (Denmark)

    Hjorth, Rune; Hansen, Steffen Foss; Jacobs, Molly;

    2017-01-01

    The use of alternatives assessment to substitute hazardous chemicals with inherently safer options is gaining momentum worldwide as a legislative and corporate strategy to minimize consumer, occupational, and environmental risks. Engineered nanomaterials represent an interesting case for alternat......The use of alternatives assessment to substitute hazardous chemicals with inherently safer options is gaining momentum worldwide as a legislative and corporate strategy to minimize consumer, occupational, and environmental risks. Engineered nanomaterials represent an interesting case...... for alternatives assessment approaches as they can be considered both emerging “chemicals” of concern, as well as potentially safer alternatives to hazardous chemicals. However, comparing the hazards of nanomaterials to traditional chemicals or to other nanomaterials is challenging and critical elements...... in chemical hazard and exposure assessment may have to be fundamentally altered to sufficiently address nanomaterials. The aim of this paper is to assess the overall applicability of alternatives assessment methods for nanomaterials and outline recommendations to enhance their use in this context. This paper...

  7. Defining food sampling strategy for chemical risk assessment

    OpenAIRE

    Wesolek, Nathalie; Roudot, Alain-Claude

    2012-01-01

    International audience; Collection of accurate and reliable data is a prerequisite for informed risk assessment and risk management. For chemical contaminants in food, contamination assessments enable consumer protection and exposure assessments. And yet, the accuracy of a contamination assessment depends on both chemical analysis and sampling plan performance. A sampling plan is always used when the contamination level of a food lot is evaluated, due to the fact that the whole lot can not be...

  8. Classification of Chemical Substances and Adverse Effects of Chemical Substances on Human Health

    OpenAIRE

    Söyleriz, Yüksel

    2015-01-01

    In this study, classification of chemical substances and adverse effects of chemical substances on human health in European Union and Turkey are assessed. Method In this study, national and international legislation and practices in the countries of the European Union are reviewed.

  9. Effect of chemical peeling on photocarcinogenesis.

    Science.gov (United States)

    Abdel-Daim, Mohamed; Funasaka, Yoko; Kamo, Tsuneyoshi; Ooe, Masahiko; Matsunaka, Hiroshi; Yanagita, Emmy; Itoh, Tomoo; Nishigori, Chikako

    2010-10-01

    Chemical peeling is one of the dermatological treatments available for certain cutaneous diseases and conditions or improvement of cosmetic appearance of photo-aged skin. We assessed the photo-chemopreventive effect of several clinically used chemical peeling agents on the ultraviolet-irradiated skin of hairless mice. Chemical peeling was done using 35% glycolic acid dissolved in distilled water, 30% salicylic acid in ethanol, and 10% or 35% trichloroacetic acid in distilled water at the right back of ultraviolet-irradiated hairless mice every 2 weeks for glycolic acid, salicylic acid and 10% trichloroacetic acid, and every 4 weeks for 35% trichloroacetic acid for a total of 18 weeks after the establishment of photo-aged mice by irradiation with ultraviolet B range light three times a week for 14 weeks at a total dose of 6.66 J/cm(2) . Tumor formation was assessed every week. Skin specimens were taken from treated and non-treated area for evaluation under microscopy, evaluation of p53 expression and mRNA expression of cyclooxygenase-2. Serum level of prostaglandin E(2) was also evaluated. All types of chemical peeling reduced tumor formation in treated mice, mostly in the treated area but also in the non-treated area. Peeling suppressed retention of p53-positive abnormal cells and reduced mRNA expression of cyclooxygenase-2 in treated skin. Further, serum prostaglandin E(2) level was decreased in chemical peeling treated mice. These results indicate that chemical peeling with glycolic acid, salicylic acid and trichloroacetic acid could serve tumor prevention by removing photo-damaged cells.

  10. Effects of chemical dispersants on oil spill drift paths in the German Bight—probabilistic assessment based on numerical ensemble simulations

    Science.gov (United States)

    Schwichtenberg, Fabian; Callies, Ulrich; Groll, Nikolaus; Maßmann, Silvia

    2016-06-01

    Oil dispersed in the water column remains sheltered from wind forcing, so that an altered drift path is a key consequence of using chemical dispersants. In this study, ensemble simulations were conducted based on 7 years of simulated atmospheric and marine conditions, evaluating 2,190 hypothetical spills from each of 636 cells of a regular grid covering the inner German Bight (SE North Sea). Each simulation compares two idealized setups assuming either undispersed or fully dispersed oil. Differences are summarized in a spatial map of probabilities that chemical dispersant applications would help prevent oil pollution from entering intertidal coastal areas of the Wadden Sea. High probabilities of success overlap strongly with coastal regions between 10 m and 20 m water depth, where the use of chemical dispersants for oil spill response is a particularly contentious topic. The present study prepares the ground for a more detailed net environmental benefit analysis (NEBA) accounting also for toxic effects.

  11. Risk assessment and emerging chemicals hazards in foods

    Directory of Open Access Journals (Sweden)

    Umberto Moscato

    2007-03-01

    Full Text Available The main beliefs relating to the risk assessment of chemicals in foods, new chemicals in raw material as well as in food processing are briefly presented. Evaluation reviews of representative chemicals found in traditional and novel foods are given. Old and new processes or newly recognized compounds, that require careful assessment in terms of their potential human health impact, are discussed. As example of processing-related contaminants, a risk assessment for acrylamide, is described, providing two different approaches in food safety assessment and the management of carcinogenic contaminants.

  12. A novel approach: chemical relational databases, and the role of the ISSCAN database on assessing chemical carcinogenicity.

    Science.gov (United States)

    Benigni, Romualdo; Bossa, Cecilia; Richard, Ann M; Yang, Chihae

    2008-01-01

    Mutagenicity and carcinogenicity databases are crucial resources for toxicologists and regulators involved in chemicals risk assessment. Until recently, existing public toxicity databases have been constructed primarily as "look-up-tables" of existing data, and most often did not contain chemical structures. Concepts and technologies originated from the structure-activity relationships science have provided powerful tools to create new types of databases, where the effective linkage of chemical toxicity with chemical structure can facilitate and greatly enhance data gathering and hypothesis generation, by permitting: a) exploration across both chemical and biological domains; and b) structure-searchability through the data. This paper reviews the main public databases, together with the progress in the field of chemical relational databases, and presents the ISSCAN database on experimental chemical carcinogens.

  13. Tools and perspectives for assessing chemical mixtures and multiple stressors

    DEFF Research Database (Denmark)

    Løkke, Hans; Ragas, Ad M. J.; Holmstrup, Martin

    2013-01-01

    The present paper summarizes the most important insights and findings of the EU NoMiracle project with a focus on (1) risk assessment of chemical mixtures, (2) combinations of chemical and natural stressors, and (3) the receptor-oriented approach in cumulative risk assessment. The project aimed a...... is suggested. The results are discussed in the light of recent developments in risk assessment of mixtures and multiple stressors....

  14. Risk assessment of endocrine active chemicals: identifying chemicals of regulatory concern.

    Science.gov (United States)

    Bars, Remi; Fegert, Ivana; Gross, Melanie; Lewis, Dick; Weltje, Lennart; Weyers, Arnd; Wheeler, James R; Galay-Burgos, Malyka

    2012-10-01

    (ECETOC, 2011), the task force developed further guidance, which is presented in this paper. For human health assessments these factors include the relevance to humans of the endocrine mechanism of toxicity, the specificity of the endocrine effects with respect to other potential toxic effects, the potency of the chemical to induce endocrine toxicity and consideration of exposure levels. For ecotoxicological assessments the key considerations include specificity and potency, but also extend to the consideration of population relevance and negligible exposure. It is intended that these complement and reinforce the approach originally described and previously published in this journal (Bars et al., 2011a,b).

  15. Portfolio Assessment on Chemical Reactor Analysis and Process Design Courses

    Science.gov (United States)

    Alha, Katariina

    2004-01-01

    Assessment determines what students regard as important: if a teacher wants to change students' learning, he/she should change the methods of assessment. This article describes the use of portfolio assessment on five courses dealing with chemical reactor and process design during the years 1999-2001. Although the use of portfolio was a new…

  16. Ecological food web analysis for chemical risk assessment.

    Science.gov (United States)

    Preziosi, Damian V; Pastorok, Robert A

    2008-12-01

    Food web analysis can be a critical component of ecological risk assessment, yet it has received relatively little attention among risk assessors. Food web data are currently used in modeling bioaccumulation of toxic chemicals and, to a limited extent, in the determination of the ecological significance of risks. Achieving more realism in ecological risk assessments requires new analysis tools and models that incorporate accurate information on key receptors in a food web paradigm. Application of food web analysis in risk assessments demands consideration of: 1) different kinds of food webs; 2) definition of trophic guilds; 3) variation in food webs with habitat, space, and time; and 4) issues for basic sampling design and collection of dietary data. The different kinds of food webs include connectance webs, materials flow webs, and functional (or interaction) webs. These three kinds of webs play different roles throughout various phases of an ecological risk assessment, but risk assessors have failed to distinguish among web types. When modeling food webs, choices must be made regarding the level of complexity for the web, assignment of species to trophic guilds, selection of representative species for guilds, use of average diets, the characterization of variation among individuals or guild members within a web, and the spatial and temporal scales/dynamics of webs. Integrating exposure and effects data in ecological models for risk assessment of toxic chemicals relies on coupling food web analysis with bioaccumulation models (e.g., Gobas-type models for fish and their food webs), wildlife exposure models, dose-response models, and population dynamics models.

  17. Life Cycle assessment of basic chemicals

    DEFF Research Database (Denmark)

    Olsen, Stig Irving

    in the survey did not think LCA is sufficiently fit to support strategic decision making. Because, the chemical industry is a major supplier to other product systems the major incentive to perform LCAs has been to comply with customer requirements. An LCA may not always need to be very detailed to fulfil......, the most important application are in research and development to improve the environmental performance of processes and products, and as support for strategic decision making. However, the coherence between LCA and decision making needs to be addressed more specifically because most companies...... accordance between the potential impact predicted in the LCA and the occurrence of actual impacts. The interpretation phase of the LCA checks the completeness and consistency of the results in relation to the goal and scope. LCA is mainly applied for internal purposes in the chemical industry. Typically...

  18. Threshold of Toxicological Concern (TTC) and Mixture Effects of Chemicals

    OpenAIRE

    Wennermark, Henrik

    2014-01-01

    The threshold of toxicological concern (TTC) has been proposed as a novel tool in the risk assessment of chemicals, which based on knowledge of chemical structure, can set safe-levels without the necessity of performing expensive and time consuming animal toxicity experiments. However, questions have been raised whether the TTC approach, in a sufficient manner, are capable of setting safe thresholds in the context of chemicals mixture effects. This is the subject for this project. The current...

  19. 76 FR 77252 - Established Assessment of Annual Needs for the List I Chemicals Ephedrine, Pseudoephedrine, and...

    Science.gov (United States)

    2011-12-12

    ... 2012'' was published in the Federal Register (76 FR 56809). That notice proposed the 2012 assessment of..., Pseudoephedrine, and Phenylpropanolamine for 2012 AGENCY: Drug Enforcement Administration (DEA), Department of... the List I chemicals ephedrine, pseudoephedrine, and phenylpropanolamine. DATES: Effective...

  20. Assessing the Effect of Organic Compounds, Biofertilizers and Chemical Fertilizers on Morphological Properties,yield and Yield Components of Forage Sorghum (Sorghum bicolor

    Directory of Open Access Journals (Sweden)

    A.H Saeidnejad

    2012-12-01

    Full Text Available Recently, using the source of organic fertilizers and biofertilizers in sustainable crop production is growing. In order to evaluate the effect of organic compounds, biofertilizers and chemical fertilizer on morphological properties, yield and yield components of forage Sorghum (sorghum bicolor a field experiment was conducted in the Research Farm, College of Agriculture, Ferdowsi University of Mashhad in 2008.The treatments were seed inoculation with the combination of Azotobacter chroococcum and Azospirillum brasilense, Compost (15 t/ha, Vermicompost (10 t/ha, seed inoculation with Azotobacter and Azospirillum and compost (10t/ha, seed inoculation with Azotobacter chroococcum and Azospirillum brasilense and Vermicompost (7t/ha, seed inoculation with Pseudomonas flurescence, seed inoculation with Pseudomonas flurescence and Azotobacter chroococcum and Azospirillum brasilense combination, seed inoculation with Pseudomonas flurescence and compost (15t/ha, chemical fertilizer (80 kg/h urea fertilizer and 50 kg/h super phosphate fertilizer and control. Harvesting was performed in 2 cuts in flowering stage. Plant height, number of tiller per plant and SPAD reading was significantly affected by the treatments. Stem diameter was not affected by any treatments. There was a significant difference among all treatments in terms of fresh and dry forage yield. There were no significant differences among all treatments in terms of stem and leaf dry matter. In general, result of this experiment indicated that organic amendments and biofertilizers could be acceptable alternatives for chemical fertilizers.

  1. Risk assessment and management of new and existing chemicals

    NARCIS (Netherlands)

    Leeuwen, C.J. van; Bro-Rasmussen, F.; Feijtel, T.C.J.; Arndt, R.; Bussian, B.M.; Calamari, D.; Glynn, P.; Grandy, N.J.; Hansen, B.; Hemmen, J.J.van; Hurst, P.; King, N.; Koch, R.; Müller, M.; Solbé, J.F.; Speijers, G.A.B.; Vermeire, T.

    1996-01-01

    An evaluation was made of the recently developed risk assessment methodologies for new and existing chemicals in the European Communities. The evaluation also included the methodologies to prioritize chemicals and procedures for risk management, i.e., the (draft) guidance document for the developmen

  2. Assessment of dermal exposure to chemicals

    NARCIS (Netherlands)

    Hemmen, J.J. van; Brouwer, D.H.

    1995-01-01

    The methods for the dermal exposure assessment vary in their complexity and are in some sense complementary to each other. The most easy-to-use methods involve a pseudo-skin-approach, such as gloves and removal by washing. In some cases generic modelling appears to be possible. The experimental meth

  3. Assessment of the abiotic and biotic effects of sodium metabisulphite pulses discharged from desalination plant chemical treatments on seagrass (Cymodocea nodosa) habitats in the Canary Islands.

    Science.gov (United States)

    Portillo, E; Ruiz de la Rosa, M; Louzara, G; Ruiz, J M; Marín-Guirao, L; Quesada, J; González, J C; Roque, F; González, N; Mendoza, H

    2014-03-15

    Reverse osmosis membranes at many desalination plants are disinfected by periodic shock treatments with sodium metabisulphite, which have potentially toxic effects to the environment for marine life, although no empirical and experimental evidence for this is yet available. The aim of this study was to characterise for the first time, the physico-chemical modification of the marine environment and its biological effects, caused by hypersaline plumes during these membrane cleaning treatments. The case study was the Maspalomas II desalination plant, located in the south of Gran Canaria (Canary Islands, Spain). Toxicity bioassays were performed on marine species characteristic for the infralittoral soft bottoms influenced by the brine plume (Synodus synodus and Cymodocea nodosa), and revealed a high sensitivity to short-term exposure to low sodium metabisulphite concentrations. The corrective measure of incorporating a diffusion system with Venturi Eductors reduced nearly all the areas of influence, virtually eliminating the impact of the disinfectant.

  4. Chemical and radiological vulnerability assessment in urban areas

    Directory of Open Access Journals (Sweden)

    Stojanović Božidar

    2006-01-01

    Full Text Available Cities and towns are faced with various types of threat from the extraordinary events involving chemical and radiological materials as exemplified by major chemical accidents, radiological incidents, fires, explosions, traffic accidents, terrorist attacks, etc. On the other hand, many sensitive or vulnerable assets exist within cities, such as: settlements, infrastructures, hospitals, schools, churches, businesses, government, and others. Besides emergency planning, the land use planning also represents an important tool for prevention or reduction of damages on people and other assets due to unwanted events. This paper considers development of method for inclusion vulnerability assessment in land use planning with objective to assess and limit the consequences in cities of likely accidents involving hazardous materials. We made preliminary assessment of criticality and vulnerability of the assets within Belgrade city area in respect to chemical sites and transportation roads that can be exposed to chemical accidents, or terrorist attacks.

  5. The assessment of treated wastewater quality and the effects of mid-term irrigation on soil physical and chemical properties (case study: Bandargaz-treated wastewater)

    Science.gov (United States)

    Kaboosi, Kami

    2016-05-01

    This study was conducted to investigate the characteristics of inflow and outflow wastewater of the Bandargaz wastewater treatment plant on the basis of the data collection of operation period and the samples taken during the study. Also the effects of mid-term use of the wastewater for irrigation (from 2005 to 2013) on soil physical and chemical characteristics were studied. For this purpose, 4 samples were taken from the inflow and outflow wastewater and 25 quality parameters were measured. Also, the four soil samples from a depth of 0-30 cm of two rice field irrigated with wastewater in the beginning and middle of the planting season and two samples from one adjacent rice field irrigated with fresh water were collected and their chemical and physical characteristics were determined. Average of electrical conductivity, total dissolved solids, sodium adsorption ratio, chemical oxygen demand and 5 days biochemical oxygen demand in treated wastewater were 1.35 dS/m, 707 ppm, 0.93, 80 ppm and 40 ppm, respectively. Results showed that although some restrictions exist about chlorine and bicarbonate, the treated wastewater is suitable for irrigation based on national and international standards and criteria. In comparison with fresh water, the mid-term use of wastewater caused a little increase of soil salinity. However, it did not lead to increase of soil salinity beyond rice salinity threshold. Also, there were no restrictions on soil in the aspect of salinity and sodium hazard on the basis of many irrigated soil classifications. In comparison with fresh water, the mid-term use of wastewater caused the increase of total N, absorbable P and absorbable K in soil due to high concentration of those elements in treated wastewater.

  6. Human exposure assessment: Approaches for chemicals (REACH) and biocides (BPD)

    NARCIS (Netherlands)

    Hemmen, J.J. van; Gerritsen-Ebben, R.

    2008-01-01

    The approaches that are indicated in the various guidance documents for the assessment of human exposure for chemicals and biocides are summarised. This reflects the TNsG (Technical notes for Guidance) version 2: human exposure assessment for biocidal products (1) under the BPD (Biocidal Products Di

  7. Assessment of Hazardous Chemicals Risk in Fur Industry in Lithuania

    Directory of Open Access Journals (Sweden)

    Birutė Vaitelytė

    2010-04-01

    Full Text Available The article describes the research on the possibilities of hazardous chemicals replacement with less hazardous substances. This issue has become of special importance to industrial companies after the adoption of the REACH Regulation. The article examines fur industry and traditional chemicals used in it, namely, sodium dichromate, formaldehyde, and naphthalene. Because of their properties these chemicals are pretending to be included in the REACH Regulation lists of the authorised chemicals. The risks of quasi-materials to the workplaces and the environment have been studied. This research has also looked for the alternatives to hazardous chemicals and has conducted their risk assessment. The analyzed chemicals have been compared with their alternatives with a view of disclosing specific risk reduction.

  8. Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cowan-Ellsberry, Christina E.; McLachlan, Michael S.; Arnot, Jon A.; MacLeod, Matthew; McKone, Thomas E.; Wania, Frank

    2008-11-01

    Fate and exposure modeling has not thus far been explicitly used in the risk profile documents prepared to evaluate significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of POP and PBT chemicals in the environment. The goal of this paper is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include: (1) Benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk. (2) Directly estimating the exposure of the environment, biota and humans to provide information to complement measurements, or where measurements are not available or are limited. (3) To identify the key processes and chemical and/or environmental parameters that determine the exposure; thereby allowing the effective prioritization of research or measurements to improve the risk profile. (4) Predicting future time trends including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and whether the assumptions and input data are relevant in the context of the application

  9. Curriculum Assessment as a Direct Tool in ABET Outcomes Assessment in a Chemical Engineering Programme

    Science.gov (United States)

    Abu-Jdayil, Basim; Al-Attar, Hazim

    2010-01-01

    The chemical engineering programme at the United Arab Emirates University is designed to fulfil the Accreditation Board for Engineering and Technology (ABET) (A-K) EC2000 criteria. The Department of Chemical & Petroleum Engineering has established a well-defined process for outcomes assessment for the chemical engineering programme in order to…

  10. Should the scope of human mixture risk assessment span legislative/regulatory silos for chemicals?

    Science.gov (United States)

    Evans, Richard M; Martin, Olwenn V; Faust, Michael; Kortenkamp, Andreas

    2016-02-01

    Current chemicals regulation operates almost exclusively on a chemical-by-chemical basis, however there is concern that this approach may not be sufficiently protective if two or more chemicals have the same toxic effect. Humans are indisputably exposed to more than one chemical at a time, for example to the multiple chemicals found in food, air and drinking water, and in household and consumer products, and in cosmetics. Assessment of cumulative risk to human health and/or the environment from multiple chemicals and routes can be done in a mixture risk assessment (MRA). Whilst there is a broad consensus on the basic science of mixture toxicology, the path to regulatory implementation of MRA within chemical risk assessment is less clear. In this discussion piece we pose an open question: should the scope of human MRA cross legislative remits or 'silos'? We define silos as, for instance, legislation that defines risk assessment practice for a subset of chemicals, usually on the basis of substance/product, media or process orientation. Currently any form of legal mandate for human MRA in the EU is limited to only a few pieces of legislation. We describe two lines of evidence, illustrated with selected examples, that are particularly pertinent to this question: 1) evidence that mixture effects have been shown for chemicals regulated in different silos and 2) evidence that humans are co-exposed to chemicals from different silos. We substantiate the position that, because there is no reason why chemicals allocated to specific regulatory silos would have non-overlapping risk profiles, then there is also no reason to expect that MRA limited only to chemicals within one silo can fully capture the risk that may be present to human consumers. Finally, we discuss possible options for implementation of MRA and we hope to prompt wider discussion of this issue.

  11. Informational uncertainties of risk assessment about accidents of chemicals

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An analysis system of informational uncertainties for accidental risk assessment of chemicals is introduced. Statistical test methods and fuzzy sets method can do the quantitative analysis of the input parameters. The uncertainties of the model can be used by quantitative compared method for the leakage accidents of chemicals. The estimation of the leaking time is important for discussing accidental source term. The uncertain analyses of the release accident for pipeline gas (CO) liquid chlorine and liquid propane gas (LPG) have been discussed.

  12. Integrating exposure into chemical alternatives assessment using a qualitative approach

    DEFF Research Database (Denmark)

    Greggs, Bill; Arnold, Scott; Burns, T. E.

    2016-01-01

    Most alternatives assessments (AA) published to date are largely hazard-based rankings, and as such may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. With an assessment goal of identifying an alternative chemical that is more sustainable...... Sustainable Chemical Alternatives Technical Committee, which consists of scientists from academia, industry, government, and NGOs, has developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have a higher human or environmental...... exposure potential, which could trigger a higher-tiered, more quantitative exposure assessment on the alternatives being considered, minimizing the likelihood of regrettable substitution. This talk will demonstrate an approach for including chemical- and product-related exposure information...

  13. Thyroid effects of endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Boas, Malene; Feldt-Rasmussen, Ulla; Main, Katharina M

    2012-01-01

    In recent years, many studies of thyroid-disrupting effects of environmental chemicals have been published. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing organism may have deleterious effects on neurological outcome. Chemicals may exert ...

  14. Health risk assessment for chemical exposures of military interest

    NARCIS (Netherlands)

    Langenberg, J.P.; Polhuijs, M.; Sijbranda, T.

    2016-01-01

    Participation in military operations is accompanied by health hazards resulting from exposure to chemical substances from natural and anthropogenic sources. Historically, focus on toxicological risks has been on the health effects of exposure to chemical warfare agents (CW A). In recent years the aw

  15. Design and preparation of market baskets of European Union commercial baby foods for the assessment of infant exposure to food chemicals and to their effects.

    Science.gov (United States)

    Piccinelli, R; Pandelova, M; Le Donne, C; Ferrari, M; Schramm, K-W; Leclercq, C

    2010-10-01

    The assessment of acute and chronic dietary exposure to contaminants in baby foods is needed to ensure healthy infant growth. Monthly European Union market baskets of commercial baby foods were designed for the first 9 months of life by the 'babyfood' study group of the CASCADE Network of Excellence for the specific purpose of assessing exposure to potentially toxic substances in infants fed with such foods. The present paper reports the different steps that led to the preparation of monthly pooled samples of commercial baby foods ('Infant formulae and follow-on formulae' and 'Other baby foods') that may constitute the extreme case of the diet for an infant who would not be breast fed at all. Several market baskets were generated for an 'average European Union infant' and for infants of four selected countries (Italy, Sweden, Spain, and the Slovakia), fed with either milk infant formulae, soy infant formulae or hypoallergenic infant formulae and weaned (at the fifth month) with commercial baby foods and beverages available on the European Union market. Market share data for 2007 for baby foods were used to design the baskets. Holding companies and the name of all their products were identified. Monthly diets for European Union infants were elaborated in terms of food categories (e.g. infant cereals) of typologies of products (e.g. infant cereals without gluten) and of a specific product. The number of baskets generated was 30 for 'Infant formulae and follow-on formulae' (including 62 products) and 13 for 'Other baby foods' (including 35 products). These market baskets were designed to be used for the determination of certain contaminants and nutrients in the diet of European Union infants and for the assessment of their effects on infant health.

  16. Chemical footprint: a methodological framework for bridging life cycle assessment and planetary boundaries for chemical pollution.

    Science.gov (United States)

    Sala, Serenella; Goralczyk, Malgorzata

    2013-10-01

    The development and use of footprint methodologies for environmental assessment are increasingly important for both the scientific and political communities. Starting from the ecological footprint, developed at the beginning of the 1990s, several other footprints were defined, e.g., carbon and water footprint. These footprints-even though based on a different meaning of "footprint"-integrate life cycle thinking, and focus on some challenging environmental impacts including resource consumption, CO2 emission leading to climate change, and water consumption. However, they usually neglect relevant sources of impacts, as those related to the production and use of chemicals. This article presents and discusses the need and relevance of developing a methodology for assessing the chemical footprint, coupling a life cycle-based approach with methodologies developed in other contexts, such as ERA and sustainability science. Furthermore, different concepts underpin existing footprint and this could be the case also of chemical footprint. At least 2 different approaches and steps to chemical footprint could be envisaged, applicable at the micro- as well as at the meso- and macroscale. The first step (step 1) is related to the account of chemicals use and emissions along the life cycle of a product, sector, or entire economy, to assess potential impacts on ecosystems and human health. The second step (step 2) aims at assessing to which extent actual emission of chemicals harm the ecosystems above their capability to recover (carrying capacity of the system). The latter step might contribute to the wide discussion on planetary boundaries for chemical pollution: the thresholds that should not be surpassed to guarantee a sustainable use of chemicals from an environmental safety perspective. The definition of what the planetary boundaries for chemical pollution are and how the boundaries should be identified is an on-going scientific challenge for ecotoxicology and ecology. In

  17. Effect of Chemicals on Chemical Mechanical Polishing of Glass Substrates

    Institute of Scientific and Technical Information of China (English)

    WANG Liang-Yong; ZHANG Kai-Liang; SONG Zhi-Tang; FENG Song-Lin

    2007-01-01

    @@ We investigate the effect of chemicals on chemical mechanical polishing (CMP) of glass substrates. Ceria slurry in an ultra-low concentration of 0.25wt.% is used and characterized by scanning electron microscopy. Three typical molecules, i.e. acetic acid, citric acid and sodium acrylic polymer, are adopted to investigate the effect on CMP performance in terms of material removal rate (MRR) and surface quality. The addition of sodium acrylic polymer shows the highest MRR as well as the best surface by atomic force microscopy after CMP, vhile the addition of citric acid shows the worst performance. These results reveal a mechanism that a long-chain molecule without any branches rather than small molecules and common molecules with ramose abundant-electron groups is better for the dispersion of the slurry and thus better for the CMP process.

  18. Structure activity relationships to assess new chemicals under TSCA

    Energy Technology Data Exchange (ETDEWEB)

    Auletta, A.E. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    Under Section 5 of the Toxic Substances Control Act (TSCA), manufacturers must notify the US Environmental Protection Agency (EPA) 90 days before manufacturing, processing, or importing a new chemical substance. This is referred to as a premanufacture notice (PMN). The PMN must contain certain information including chemical identity, production volume, proposed uses, estimates of exposure and release, and any health or environmental test data that are available to the submitter. Because there is no explicit statutory authority that requires testing of new chemicals prior to their entry into the market, most PMNs are submitted with little or no data. As a result, EPA has developed special techniques for hazard assessment of PMN chemicals. These include (1) evaluation of available data on the chemical itself, (2) evaluation of data on analogues of the PMN, or evaluation of data on metabolites or analogues of metabolites of the PMN, (3) use of quantitative structure activity relationships (QSARs), and (4) knowledge and judgement of scientific assessors in the interpretation and integration of the information developed in the course of the assessment. This approach to evaluating potential hazards of new chemicals is used to identify those that are most in need of addition review of further testing. It should not be viewed as a replacement for testing. 4 tabs.

  19. Interactions between chemical and climate stressors: A role for mechanistic toxicology in assessing climate change risks

    Science.gov (United States)

    Hooper, Michael J.; Ankley, Gerald T.; Cristol, Daniel A.; Maryoung, Lindley A.; Noyes, Pamela D.; Pinkerton, Kent E.

    2013-01-01

    Incorporation of global climate change (GCC) effects into assessments of chemical risk and injury requires integrated examinations of chemical and nonchemical stressors. Environmental variables altered by GCC (temperature, precipitation, salinity, pH) can influence the toxicokinetics of chemical absorption, distribution, metabolism, and excretion as well as toxicodynamic interactions between chemicals and target molecules. In addition, GCC challenges processes critical for coping with the external environment (water balance, thermoregulation, nutrition, and the immune, endocrine, and neurological systems), leaving organisms sensitive to even slight perturbations by chemicals when pushed to the limits of their physiological tolerance range. In simplest terms, GCC can make organisms more sensitive to chemical stressors, while alternatively, exposure to chemicals can make organisms more sensitive to GCC stressors. One challenge is to identify potential interactions between nonchemical and chemical stressors affecting key physiological processes in an organism. We employed adverse outcome pathways, constructs depicting linkages between mechanism-based molecular initiating events and impacts on individuals or populations, to assess how chemical- and climate-specific variables interact to lead to adverse outcomes. Case examples are presented for prospective scenarios, hypothesizing potential chemical–GCC interactions, and retrospective scenarios, proposing mechanisms for demonstrated chemical–climate interactions in natural populations. Understanding GCC interactions along adverse outcome pathways facilitates extrapolation between species or other levels of organization, development of hypotheses and focal areas for further research, and improved inputs for risk and resource injury assessments.

  20. Environmental assessments of sea dumped chemical warfare agents

    DEFF Research Database (Denmark)

    Sanderson, Hans; Fauser, Patrik

    This is a report on the information gathered during work related to sea dumped chemical warfare agents. It mainly reviews the work conducted in relation to the installation of the two Nord Stream gas pipeline from 2008-2012. The focus was on the weight-of-evidence risk assessment of disturbed CWA...

  1. Can water quality of tubewells be assessed without chemical testing?

    Science.gov (United States)

    Hoque, Mohammad A.; Butler, Adrian P.

    2016-04-01

    Arsenic is one of the major pollutants found in aquifers on a global scale. The screening of tubewells for arsenic has helped many people to avoid drinking from highly polluted wells in the Bengal Delta (West Bengal and Bangladesh). However, there are still many millions of tubewells in Bangladesh yet to be tested, and a substantial proportion of these are likely to contain excessive arsenic. Due to the level of poverty and lack of infrastructure, it is unlikely that the rest of the tubewells will be tested quickly. However, water quality assessment without needing a chemical testing may be helpful in this case. Studies have found that qualitative factors, such as staining in the tubewell basement and/or on utensils, can indicate subsurface geology and water quality. The science behind this staining is well established, red staining is associated with iron reduction leading to release of arsenic whilst black staining is associated with manganese reduction (any release of arsenic due to manganese reduction is sorbed back on the, yet to be reduced, iron), whereas mixed staining may indicate overlapping manganese and iron reduction at the tubewell screen. Reduction is not uniform everywhere and hence chemical water quality including dissolved arsenic varies from place to place. This is why coupling existing tubewell arsenic information with user derived staining data could be useful in predicting the arsenic status at a particular site. Using well location, depth, along with colour of staining, an assessment of both good (nutrients) and bad (toxins and pathogens) substances in the tubewell could be provided. Social-network technology, combined with increasing use of smartphones, provides a powerful opportunity for both sharing and providing feedback to the user. Here we outline how a simple digital application can couple the reception both qualitative and quantitative tubewell data into a centralised interactive database and provide manipulated feedback to an

  2. Geometrical criteria versus quantum chemical criteria for assessment of intramolecular hydrogen bond (IMHB) interaction: A computational comparison into the effect of chlorine substitution on IMHB of salicylic acid in its lowest energy ground state conformer

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bijan Kumar [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Calcutta 700009 (India); Guchhait, Nikhil, E-mail: nikhil.guchhait@rediffmail.com [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Calcutta 700009 (India)

    2013-02-01

    Highlights: ► Intramolecular hydrogen bonding (IMHB) in salicylic acid and its chloro derivatives. ► A complex effect of +R and −I effect of chlorine substituents on IMHB energy. ► Interplay between IMHB energy and aromaticity. ► Directional nature of IMHB from quantum chemical assessment. ► Quantum chemical treatment vs. geometrical criteria to assess weak interaction. - Abstract: Density functional theory based computational study has been performed to characterize intramolecular hydrogen bonding (IMHB) interaction in a series of salicylic acid derivatives varying in chlorine substitution on the benzene ring. The molecular systems studied are salicylic acid, 5-chlorosalicylic acid, 3,5-dichlorosalicylic acid and 3,5,6-tricholorosalicylic acid. Major emphasis is rendered on the analysis of IMHB interaction by calculation of electron density ρ(r) and Laplacian ∇{sup 2}ρ(r) at the bond critical point using atoms-in-molecule theory. Topological features, energy densities based on ρ(r) through perturbing the intramolecular H-bond distances suggest that at equilibrium geometry the IMHB interaction develops certain characteristics typical of covalent interaction. The interplay between aromaticity and resonance-assisted hydrogen bonding (RAHB) is discussed using both geometrical and magnetic criteria as the descriptors of aromaticity. The optimized geometry features, molecular electrostatic potential map analysis are also found to produce a consensus view in relation with the formation of RAHB in these systems.

  3. Holistic Metrics for Assessment of the Greenness of Chemical Reactions in the Context of Chemical Education

    Science.gov (United States)

    Ribeiro, M. Gabriela T. C.; Machado, Adelio A. S. C.

    2013-01-01

    Two new semiquantitative green chemistry metrics, the green circle and the green matrix, have been developed for quick assessment of the greenness of a chemical reaction or process, even without performing the experiment from a protocol if enough detail is provided in it. The evaluation is based on the 12 principles of green chemistry. The…

  4. Research on quantitative risk assessment in chemical park based on domino effect model%基于多米诺效应的化工园区定量风险评估方法研究

    Institute of Scientific and Technical Information of China (English)

    马科伟; 朱建新; 包士毅

    2011-01-01

    In order to quantitatively assess the risk of chemical park, a domino-based model was introduced for modeling the domino-caused risks. The definition, characteristics and mechanism of domino effect were introduced in this model. The probability of damages and human vulnerabilities caused by different primary hazardous events was also proposed and then used for the quantitative assessment of both individual and societal risks created by the chemical park. The individual and societal risks (F N curve), together with associated quantitative methods were also involved. It was found that, by applying the method in real case, the risk caused by domino effect can be dramatically increased. This finding would be beneficial to the safety planning and risk management of chemical parks.%探讨了多米诺效应的定义,特点及其发生机理,对基于多米诺效应的定量风险评估方法进行了研究.针对不同初始事件的物理效应因素给出了目标设备损害几率的计算方法,运用人体损伤模型对事故后果进行定量分析,量化了风险,给出个人风险图和F-N社会风险曲线.实例计算表明:多米诺效应明显扩大了事故风险.通过多米诺效应分析有利于园区的安全规划和管理.

  5. Integrating exposure into chemical alternatives assessment using a qualitative approach

    DEFF Research Database (Denmark)

    Greggs, Bill; Arnold, Scott; Burns, Thomas J.;

    2016-01-01

    could trigger a higher-tiered, more quantitative exposure assessment on the alternatives being considered. This talk will demonstrate an approach for including chemical- and product-related exposure information in a qualitative AA comparison. Starting from existing hazard AAs, a series of four chemical...... Sustainable Chemical Alternatives Technical Committee, which consists of scientists from academia, industry, government, and NGOs, has developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have a higher exposure potential, which......-product application scenarios were examined to test the concept, to understand the effort required, and to determine the value of exposure data in AA decision-making. The group has developed a classification approach for ingredient and product parameters to support comparisons between alternatives as well...

  6. Development and testing of a prototype tool for integrated assessment of chemical status in marine environments.

    Science.gov (United States)

    Andersen, Jesper H; Murray, Ciarán; Larsen, Martin M; Green, Norman; Høgåsen, Tore; Dahlgren, Elin; Garnaga-Budrė, Galina; Gustavson, Kim; Haarich, Michael; Kallenbach, Emilie M F; Mannio, Jaakko; Strand, Jakob; Korpinen, Samuli

    2016-02-01

    We report the development and application of a prototype tool for integrated assessment of chemical status in aquatic environments based on substance- and matrix-specific environmental assessment criteria (thresholds). The Chemical Status Assessment Tool (CHASE) integrates data on hazardous substances in water, sediments and biota as well as bio-effect indicators and is based on a substance- or bio-effect-specific calculation of a 'contamination ratio' being the ratio between an observed concentration and a threshold value. Values 1.0 indicate areas potentially 'affected'. These ratios are combined within matrices, i.e. for water, sediment and biota and for biological effects. The overall assessment used a 'one out, all out principle' with regard to each matrix. The CHASE tool was tested in the Baltic Sea and the North Sea in 376 assessment units. In the former, the chemical status was >1.0 in practically all areas indicating that all areas assessed were potentially affected. The North Sea included areas classified as unaffected or affected. The CHASE tool can in combination with temporal trend assessments of individual substances be advantageous for use in remedial action plans and, in particular, for the science-based evaluation of the status and for determining which specific substances are responsible for a status as potentially affected.

  7. Ecological Recovery Potential of Freshwater Organisms: Consequences for Environmental Risk Assessment of Chemicals.

    Science.gov (United States)

    Gergs, Andre; Classen, Silke; Strauss, Tido; Ottermanns, Richard; Brock, Theo C M; Ratte, Hans Toni; Hommen, Udo; Preuss, Thomas G

    2016-01-01

    Chemical contaminants released into the in the environment may have adverse effects on (non-target) species, populations and communities. The return of a stressed system to its pre-disturbance or other reference state, i.e. the ecological recovery, may depend on various factors related to the affected taxon, the ecosystem of concern and the type of stressor with consequences for the assessment and management of risks associated with chemical contaminants. Whereas the effects caused by short-term exposure might be acceptable to some extent, the conditions under which ecological recovery can serve as a decision criterion in the environmental risk assessment of chemical stressors remains to be evaluated. For a generic consideration of recovery in the risk assessment of chemicals, we reviewed case studies of natural and artificial aquatic systems and evaluate five aspects that might cause variability in population recovery time: (1) taxonomic differences and life-history variability, (2) factors related to ecosystem type and community processes, (3) type of disturbance, (4) comparison of field and semi-field studies, and (5) effect magnitude, i.e., the decline in population size following disturbance. We discuss our findings with regard to both retrospective assessments and prospective risk assessment.

  8. Chemicals from biomass: an assessment of the potential for production of chemical feedstocks from renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, T.L.; Culberson, O.L.

    1983-06-01

    This assessment of the potential for production of commodity chemicals from renewable biomass resources is based on (1) a Delphi study with 50 recognized authorities to identify key technical issues relevant to production of chemicals from biomass, and (2) a systems model based on linear programming for a commodity chemicals industry using renewable resources and coal as well as gas and petroleum-derived resources. Results from both parts of the assessment indicate that, in the absence of gas and petroleum, coal undoubtedly would be a major source of chemicals first, followed by biomass. The most attractive biomass resources are wood, agricultural residues, and sugar and starch crops. A reasonable approximation to the current product slate for the petrochemical industry could be manufactured using only renewable resources for feedstocks. Approximately 2.5 quads (10/sup 15/ Btu (1.055 x 10/sup 18/ joules)) per year of oil and gas would be released. Further use of biomass fuels in the industry could release up to an additional 1.5 quads. however, such an industry would be unprofitable under current economic conditions with existing or near-commercial technology. As fossil resources become more expensive and biotechnology becomes more efficient, the economics will be more favorable. Use of the chemicals industry model to evaluate process technologies is demonstrated. Processes are identified which have potential for significant added value to the system if process improvements can be made to improve the economics. Guidelines and recommendations for research and development programs to improve the attractiveness of chemicals from biomass are discussed.

  9. The potential role of life cycle assessment in regulation of chemicals in the European Union

    DEFF Research Database (Denmark)

    Christensen, Frans Møller; Olsen, Stig Irving

    2004-01-01

    reduction. In this process, LCA results might feed into a socio-economic analysis having similar objectives, but some methodological aspects related to system boundaries need to be sorted out. Life cycle impact assessment (LCIA) of toxic effects has traditionally been inspired by the more regulatory......- orientated risk assessment approaches. However, the increasing need for regulatory priority setting and comparative/ cumulative assessments might in the future convey LCIA principles into the regulatory framework. The same underlying databases on inherent properties of chemicals are already applied in both...... types of assessment. Similarly, data on the use and exposure of chemicals are needed within both risk assessments and LCA, and the methodologies might therefore benefit from a joint 'inventory' database. Outlook. The final outcome of the feasibility study will be an implementation plan suggesting...

  10. Integrated assessment of oil pollution using biological monitoring and chemical fingerprinting.

    Science.gov (United States)

    Lewis, Ceri; Guitart, Carlos; Pook, Chris; Scarlett, Alan; Readman, James W; Galloway, Tamara S

    2010-06-01

    A full assessment of the impact of oil and chemical spills at sea requires the identification of both the polluting chemicals and the biological effects they cause. Here, a combination of chemical fingerprinting of surface oils, tissue residue analysis, and biological effects measures was used to explore the relationship between spilled oil and biological impact following the grounding of the MSC Napoli container ship in Lyme Bay, England in January 2007. Initially, oil contamination remained restricted to a surface slick in the vicinity of the wreck, and there was no chemical evidence to link biological impairment of animals (the common limpet, Patella vulgata) on the shore adjacent to the oil spill. Secondary oil contamination associated with salvage activities in July 2007 was also assessed. Chemical analyses of aliphatic hydrocarbons and terpanes in shell swabs taken from limpet shells provided an unequivocal match with the fuel oil carried by the ship. Corresponding chemical analysis of limpet tissues revealed increased concentrations of polycyclic aromatic hydrocarbons (PAHs) dominated by phenanthrene and C1 to C3 phenanthrenes with smaller contributions from heavier molecular weight PAHs. Concurrent ecotoxicological tests indicated impairment of cellular viability (p oiled animals. These results illustrate the value of combining biological monitoring with chemical fingerprinting for the rapid identification of spilled oils and their sublethal impacts on biota in situ.

  11. Predicting Drugs Side Effects Based on Chemical-Chemical Interactions and Protein-Chemical Interactions

    Directory of Open Access Journals (Sweden)

    Lei Chen

    2013-01-01

    Full Text Available A drug side effect is an undesirable effect which occurs in addition to the intended therapeutic effect of the drug. The unexpected side effects that many patients suffer from are the major causes of large-scale drug withdrawal. To address the problem, it is highly demanded by pharmaceutical industries to develop computational methods for predicting the side effects of drugs. In this study, a novel computational method was developed to predict the side effects of drug compounds by hybridizing the chemical-chemical and protein-chemical interactions. Compared to most of the previous works, our method can rank the potential side effects for any query drug according to their predicted level of risk. A training dataset and test datasets were constructed from the benchmark dataset that contains 835 drug compounds to evaluate the method. By a jackknife test on the training dataset, the 1st order prediction accuracy was 86.30%, while it was 89.16% on the test dataset. It is expected that the new method may become a useful tool for drug design, and that the findings obtained by hybridizing various interactions in a network system may provide useful insights for conducting in-depth pharmacological research as well, particularly at the level of systems biomedicine.

  12. Gestalt Effect of Self Assessment

    Science.gov (United States)

    McDonald, Betty

    2012-01-01

    Defining self assessment as the involvement of students in identifying standards and/or criteria to apply to their work and making judgements about the extent to which they have met these criteria and standards, this paper seeks to highlight the gestalt effect of self assessment. The total effect of self assessment on the learner is greater than…

  13. Prioritization of chemicals in the aquatic environment based on risk assessment: analytical, modeling and regulatory perspective.

    Science.gov (United States)

    Guillén, D; Ginebreda, A; Farré, M; Darbra, R M; Petrovic, M; Gros, M; Barceló, D

    2012-12-01

    The extensive and intensive use of chemicals in our developed, highly technological society includes more than 100,000 chemical substances. Significant scientific evidence has lead to the recognition that their improper use and release may result in undesirable and harmful side-effects on both the human and ecosystem health. To cope with them, appropriate risk assessment processes and related prioritization schemes have been developed in order to provide the necessary scientific support for regulatory procedures. In the present paper, two of the elements that constitute the core of risk assessment, namely occurrence and hazard effects, have been discussed. Recent advances in analytical chemistry (sample pre-treatment and instrumental equipment, etc.) have allowed for more comprehensive monitoring of environmental pollution reaching limits of detection up to sub ng L(-1). Alternative to analytical measurements, occurrence models can provide risk managers with a very interesting approach for estimating environmental concentrations from real or hypothetical scenarios. The most representative prioritization schemes used for issuing lists of concerning chemicals have also been examined and put in the context of existing environmental policies for protection strategies and regulations. Finally, new challenges in the field of risk-assessment have been outlined, including those posed by new materials (i.e., nanomaterials), transformation products, multi-chemical exposure, or extension of the risk assessment process to the whole ecosystem.

  14. High production volume chemical Amine Oxide [C8-C20] category environmental risk assessment

    DEFF Research Database (Denmark)

    Sanderson, Hans; Tibazarwa, Caritas; Greggs, William

    2009-01-01

    An environmental assessment of amine oxides has been conducted under the OECD SIDS High Production Volume (HPV) Program via the Global International Council of Chemical Associations (ICCA) Amine Oxides Consortium. Amine oxides are primarily used in conjunction with surfactants in cleaning...... and personal care products. Given the lack of persistence or bioaccumulation, and the low likelihood of these chemicals partitioning to soil, the focus of the environmental assessment is on the aquatic environment. In the United States, the E-FAST model is used to estimate effluent concentrations in the United...... States from manufacturing facilities and from municipal facilities resulting from consumer product uses. Reasonable worst-case ratios of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) range from 0.04 to 0.003, demonstrating that these chemicals are a low risk...

  15. Regulatory assessment of chemicals within OECD member countries, EU and in Russia.

    Science.gov (United States)

    Fjodorova, Natalja; Novich, Marjana; Vrachko, Marjan; Kharchevnikova, Nina; Zholdakova, Zoya; Sinitsyna, Oxana; Benfenati, Emilio

    2008-01-01

    The chemical risk assessment is essesntial part of new chemical legislation registration, evaluation, and authorization of chemicals (REACH). The article presents a review of chemical legislation policies in the European Union (EU) and in Russia, and changes in chemicals regulations to meet the requirement of REACH. The risk assessment paradigm, toxicological parameters, safe limits and classification criteria used by different agencies and authorities in different countries are reported. Our investigation also focuses on comparison of chemical risk assessment criteria used in OECD member countries and in Russia. Tendencies in harmonization in accordance with the globally harmonized system of classification and labeling of chemicals (GHS) are discussed.

  16. Assessment of the effect of betaine on p16 and c-myc DNA methylation and mRNA expression in a chemical induced rat liver cancer model

    Directory of Open Access Journals (Sweden)

    Ling Wen-hua

    2009-07-01

    Full Text Available Abstract Background The development and progression of liver cancer may involve abnormal changes in DNA methylation, which lead to the activation of certain proto-oncogenes, such as c-myc, as well as the inactivation of certain tumor suppressors, such as p16. Betaine, as an active methyl-donor, maintains normal DNA methylation patterns. However, there are few investigations on the protective effect of betaine in hepatocarcinogenesis. Methods Four groups of rats were given diethylinitrosamine (DEN and fed with AIN-93G diets supplemented with 0, 10, 20 or 40 g betaine/kg (model, 1%, 2%, and 4% betaine, respectively, while the control group, received no DEN, fed with AIN-93G diet. Eight or 15 weeks later, the expression of p16 and c-myc mRNA was examined by Real-time PCR (Q-PCR. The DNA methylation status within the p16 and c-myc promoter was analyzed using methylation-specific PCR. Results Compared with the model group, numbers and areas of glutathione S-transferase placental form (GST-p-positive foci were decreased in the livers of the rats treated with betaine (P . Although the frequency of p16 promoter methylation in livers of the four DEN-fed groups appeared to increase, there is no difference among these groups after 8 or 15 weeks (P > 0.05. Betaine supplementation attenuated the down-regulation of p16 and inhibited the up-regulation of c-myc induced by DEN in a dose-dependent manner (P P . Finally, enhanced antioxidative capacity (T-AOC was observed in both the 2% and 4% betaine groups. Conclusion Our data suggest that betaine attenuates DEN-induced damage in rat liver and reverses DEN-induced changes in mRNA levels.

  17. Evaluation of Chemical Warfare Agent Percutaneous Vapor Toxicity: Derivation of Toxicity Guidelines for Assessing Chemical Protective Ensembles.

    Energy Technology Data Exchange (ETDEWEB)

    Watson, A.P.

    2003-07-24

    Percutaneous vapor toxicity guidelines are provided for assessment and selection of chemical protective ensembles (CPEs) to be used by civilian and military first responders operating in a chemical warfare agent vapor environment. The agents evaluated include the G-series and VX nerve agents, the vesicant sulfur mustard (agent HD) and, to a lesser extent, the vesicant Lewisite (agent L). The focus of this evaluation is percutaneous vapor permeation of CPEs and the resulting skin absorption, as inhalation and ocular exposures are assumed to be largely eliminated through use of SCBA and full-face protective masks. Selection of appropriately protective CPE designs and materials incorporates a variety of test parameters to ensure operability, practicality, and adequacy. One aspect of adequacy assessment should be based on systems tests, which focus on effective protection of the most vulnerable body regions (e.g., the groin area), as identified in this analysis. The toxicity range of agent-specific cumulative exposures (Cts) derived in this analysis can be used as decision guidelines for CPE acceptance, in conjunction with weighting consideration towards more susceptible body regions. This toxicity range is bounded by the percutaneous vapor estimated minimal effect (EME{sub pv}) Ct (as the lower end) and the 1% population threshold effect (ECt{sub 01}) estimate. Assumptions of exposure duration used in CPE certification should consider that each agent-specific percutaneous vapor cumulative exposure Ct for a given endpoint is a constant for exposure durations between 30 min and 2 hours.

  18. Chemical Modifications of Starch: Microwave Effect

    OpenAIRE

    Kamila Lewicka; Przemysław Siemion; Piotr Kurcok

    2015-01-01

    This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation ...

  19. Towards the regulation of aerosol emissions by their potential health impact: Assessing adverse effects of aerosols from wood combustion and ship diesel engine emissions by combining comprehensive data on the chemical composition and their toxicological effects on human lung cells

    Science.gov (United States)

    Zimmermann, R.; Streibel, T.; Dittmar, G.; Kanashova, T.; Buters, J.; Öder, S.; Paur, H. R.; Dilger, M.; Weiss, C.; Harndorf, H.; Stengel, B.; Hirvonen, M. R.; Jokiniemi, J.; Hiller, K.; Sapcariu, S.; Sippula, O.; Orasche, J.; Müller, L.; Rheda, A.; Passig, J.; Radischat, C.; Czech, H.; Tiita, P.; Jalava, P.; Kasurinen, S.; Schwemer, T.; Yli-Prilä, P.; Tissari, J.; Lamberg, H.; Schnelle-Kreis, J.

    2014-12-01

    Ship engine emissions are important regarding lung and cardiovascular diseases in coastal regions worldwide. Bio mass burning is made responsible for adverse health effects in many cities and rural regions. The Virtual Helmholtz Institute-HICE (www.hice-vi.eu) addresses chemical & physical properties and health effects of anthropogenic combustion emissions. Typical lung cell responses to combustion aerosols include inflammation and apoptosis, but a molecular link with the specific chemical composition in particular of ship emissions has not been established. Through an air-liquid interface exposure system (ALI), we exposed human lung cells at-site to exhaust fumes from a ship engine running on common heavy fuel oil (HFO) and cleaner-burning diesel fuel (DF) as well as to emissions of wood combustion compliances. A special field deployable ALI-exposition system and a mobile S2-biological laboratory were developed for this study. Human alveolar basal epithelial cells (A549 etc.) are ALI-exposed to fresh, diluted (1:40-1:100) combustion aerosols and subsequently were toxicologically and molecular-biologically characterized. Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling to characterise the cellular responses. The HFO ship emissions contained high concentrations of toxic compounds (transition metals, organic toxicants) and particle masses. The cellular responses included inflammation and oxidative stress. Surprisingly, the DF ship emissions, which predominantly contain rather "pure" carbonaceous soot and much less known toxicants, induced significantly broader biological effects, affecting essential cellular pathways (e.g., mitochondrial function and intracellular transport). Therefore the use of distillate fuels for shipping (this is the current emission reduction strategy of the IMO) appears insufficient for diminishing health effects. The study suggests rather reducing the particle emissions

  20. Risk assessment and hierarchical risk management of enterprises in chemical industrial parks based on catastrophe theory.

    Science.gov (United States)

    Chen, Yu; Song, Guobao; Yang, Fenglin; Zhang, Shushen; Zhang, Yun; Liu, Zhenyu

    2012-12-03

    According to risk systems theory and the characteristics of the chemical industry, an index system was established for risk assessment of enterprises in chemical industrial parks (CIPs) based on the inherent risk of the source, effectiveness of the prevention and control mechanism, and vulnerability of the receptor. A comprehensive risk assessment method based on catastrophe theory was then proposed and used to analyze the risk levels of ten major chemical enterprises in the Songmu Island CIP, China. According to the principle of equal distribution function, the chemical enterprise risk level was divided into the following five levels: 1.0 (very safe), 0.8 (safe), 0.6 (generally recognized as safe, GRAS), 0.4 (unsafe), 0.2 (very unsafe). The results revealed five enterprises (50%) with an unsafe risk level, and another five enterprises (50%) at the generally recognized as safe risk level. This method solves the multi-objective evaluation and decision-making problem. Additionally, this method involves simple calculations and provides an effective technique for risk assessment and hierarchical risk management of enterprises in CIPs.

  1. Assessment of chemical emissions in life cycle impact assessment - focus on low substance data availability and

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred

    2004-01-01

    chemical groups, high data availability combined with low data demand, data useable in characterisation, user friendliness and transparency. A mainly qualitative evaluation of the existing selection methods against these performance criteria shows that none of these score high on all criteria...... be significantly dependent on the inclusion of toxicity- or chemical-related impact categories. The two main reasons for poor coverage of potential toxic impacts from chemical emissions in LCA studies are lack of available data on upstream emissions (e.g. emissions during production of raw materials) and lack...... of substance data on known emissions. To be able to characterize the potential toxic impacts on humans and the environment of chemical emissions, substance data on fate and effect are needed. The second goal of this thesis is to investigate how to deal with low substance data availability on especially effect...

  2. Mass Casualty Chemical Incident Operational Framework, Assessment and Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    Greenwalt, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hibbard, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-09

    Emergency response agencies in most US communities are organized, sized, and equipped to manage those emergencies normally expected. Hospitals in particular do not typically have significant excess capacity to handle massive numbers of casualties, as hospital space is an expensive luxury if not needed. Unfortunately this means that in the event of a mass casualty chemical incident the emergency response system will be overwhelmed. This document provides a self-assessment means for emergency managers to examine their response system and identify shortfalls. It also includes lessons from a detailed analysis of five communities: Baltimore, Boise, Houston, Nassau County, and New Orleans. These lessons provide a list of potential critical decisions to allow for pre-planning and a library of best practices that may be helpful in reducing casualties in the event of an incident.

  3. Cation Effect on Copper Chemical Mechanical Polishing

    Institute of Scientific and Technical Information of China (English)

    WANG Liang-Yong; LIU Bo; SONG Zhi-Tang; FENG Song-Lin

    2009-01-01

    We examine the effect of cations in solutions containing benzotriazole (BTA) and H2O2 on copper chemical mechanical polishing (CMP). On the base of atomic force microscopy (AFM) and material removal rate (MRR) results, it is found that ammonia shows the highest MRR as well as good surface after CMP, while KOH demon-strates the worst performance. These results reveal a mechanism that sma//molecules with lone-pairs rather than molecules with steric effect and common inorganic cations are better for copper CMP process, which is indirectly confirmed by open circuit potential (OCP).

  4. Cation Effect on Copper Chemical Mechanical Polishing

    Science.gov (United States)

    Wang, Liang-Yong; Liu, Bo; Song, Zhi-Tang; Feng, Song-Lin

    2009-02-01

    We examine the effect of cations in solutions containing benzotriazole (BTA) and H2O2 on copper chemical mechanical polishing (CMP). On the base of atomic force microscopy (AFM) and material removal rate (MRR) results, it is found that ammonia shows the highest MRR as well as good surface after CMP, while KOH demonstrates the worst performance. These results reveal a mechanism that small molecules with lone-pairs rather than molecules with steric effect and common inorganic cations are better for copper CMP process, which is indirectly confirmed by open circuit potential (OCP).

  5. Using systematic reviews for hazard and risk assessment of endocrine disrupting chemicals

    Science.gov (United States)

    Beronius, Anna; Vandenberg, Laura N.

    2016-01-01

    The possibility that endocrine disrupting chemicals (EDCs) in our environment contribute to hormonally related effects and diseases observed in human and wildlife populations has caused concern among decision makers and researchers alike. EDCs challenge principles traditionally applied in chemical risk assessment and the identification and assessment of these compounds has been a much debated topic during the last decade. State of the science reports and risk assessments of potential EDCs have been criticized for not using systematic and transparent approaches in the evaluation of evidence. In the fields of medicine and health care, systematic review methodologies have been developed and used to enable objectivity and transparency in the evaluation of scientific evidence for decision making. Lately, such approaches have also been promoted for use in the environmental health sciences and risk assessment of chemicals. Systematic review approaches could provide a tool for improving the evaluation of evidence for decision making regarding EDCs, e.g. by enabling systematic and transparent use of academic research data in this process. In this review we discuss the advantages and challenges of applying systematic review methodology in the identification and assessment of EDCs. PMID:26847432

  6. Using systematic reviews for hazard and risk assessment of endocrine disrupting chemicals.

    Science.gov (United States)

    Beronius, Anna; Vandenberg, Laura N

    2015-12-01

    The possibility that endocrine disrupting chemicals (EDCs) in our environment contribute to hormonally related effects and diseases observed in human and wildlife populations has caused concern among decision makers and researchers alike. EDCs challenge principles traditionally applied in chemical risk assessment and the identification and assessment of these compounds has been a much debated topic during the last decade. State of the science reports and risk assessments of potential EDCs have been criticized for not using systematic and transparent approaches in the evaluation of evidence. In the fields of medicine and health care, systematic review methodologies have been developed and used to enable objectivity and transparency in the evaluation of scientific evidence for decision making. Lately, such approaches have also been promoted for use in the environmental health sciences and risk assessment of chemicals. Systematic review approaches could provide a tool for improving the evaluation of evidence for decision making regarding EDCs, e.g. by enabling systematic and transparent use of academic research data in this process. In this review we discuss the advantages and challenges of applying systematic review methodology in the identification and assessment of EDCs.

  7. Evaluating Chemical Dispersant Efficacy In An Experimental Wave Tank: 1, Dispersant Effectiveness As A Function Of Energy Dissipation Rate

    Science.gov (United States)

    Numerous laboratory test systems have been developed for the comparison of efficacy between various chemical oil dispersant formulations. However, for the assessment of chemical dispersant effectiveness under realistic sea state, test protocols are required to produce hydrodynam...

  8. Science based guidance for the assessment of endocrine disrupting properties of chemicals.

    Science.gov (United States)

    Bars, Remi; Broeckaert, Fabrice; Fegert, Ivana; Gross, Melanie; Hallmark, Nina; Kedwards, Tim; Lewis, Dick; O'Hagan, Sue; Panter, Grace H; Weltje, Lennart; Weyers, Arnd; Wheeler, James R; Galay-Burgos, Malyka

    2011-02-01

    The European legislation on plant protection products (Regulation (EC) No. 1107/2009) and biocides (Directive 98/8/EC), as well as the regulation concerning chemicals (Regulation (EC) No. 1907/2006 'REACH') only support the marketing and use of chemical products on the basis that they do not induce endocrine disruption in humans or non-target species. However, there is currently no agreed guidance on how to identify and evaluate endocrine activity and disruption. Consequently, an ECETOC task force was formed to provide scientific criteria that may be used within the context of these three legislative documents. Specific scientific criteria for the determination of endocrine disrupting properties that integrate information from both regulatory (eco)toxicity studies and mechanistic/screening studies are proposed. These criteria combine the nature of the adverse effects detected in studies which give concern for endocrine toxicity with an understanding of the mode of action of toxicity so that adverse effects can be explained scientifically. The criteria developed are presented in the form of flow charts for assessing relevant effects for both humans and wildlife species. In addition, since not all chemicals with endocrine disrupting properties are of equal hazard, assessment of potency is also proposed to discriminate chemicals of high concern from those of lower concern. The guidance presented in this paper includes refinements made to an initial proposal following discussion of the criteria at a workshop of invited regulatory, academic and industry scientists.

  9. Assessing Risk in Chemical Plant with Pattern Matching

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper discusses potential application of fuzzy set theory, more specifically, pattern matching, in assessing risk in chemical plants. Risk factors have been evaluated using linguistic representations of the quantity of the hazardous substance involved, its frequency of interaction with the environment, severity of its impact and the uncertainty involved in its detection in advance. For each linguistic value there is a corresponding membership function ranging over a universe of discourse. The risk scenario created by a hazard/hazardous situation having highest degree of featural value is taken as the known pattern. Each sample pattern of hazard/hazardous situation with their known featural values is then matched with the known pattern. The concept of multifeature pattern matching based on fuzzy logic is used to derive the rank ordering of process hazards. In multifeature pattern recognition/matching, a sample pattern is compared to a number of known data patterns or a known pattern is compared to a number of sample data patterns. The process assesses which known pattern resembles most closely data sample using Wang's approaching degree method. A methodology has been developed and the same has been exemplified by presenting a case example with a limited number of hazards.

  10. The chemical characterization of the gene: vicissitudes of evidential assessment.

    Science.gov (United States)

    Stegenga, Jacob

    2011-01-01

    The chemical characterization of the substance responsible for the phenomenon of "transformation" of pneumococci was presented in the now famous 1944 paper by Avery, MacLeod, and McCarty. Reception of this work was mixed. Although interpreting their results as evidence that deoxyribonucleic acid (DNA) is the molecule responsible for genetic changes was, at the time, controversial, this paper has been retrospectively celebrated as providing such evidence. The mixed and changing assessment of the evidence presented in the paper was due to the work's interpretive flexibility--the evidence was interpreted in various ways, and such interpretations were justified given the neophytic state of molecular biology and methodological limitations of Avery's transformation studies. I argue that the changing context in which the evidence presented by Avery's group was interpreted partly explains the vicissitudes of the assessments of the evidence. Two less compelling explanations of the reception are a myth-making account and an appeal to the wartime historical context of its publication.

  11. Synergistic health effects between chemical pollutants and electromagnetic fields.

    Science.gov (United States)

    Ledoigt, Gérard; Sta, Chaima; Goujon, Eric; Souguir, Dalila; El Ferjani, Ezzeddine

    2015-01-01

    Humans and ecosystems are exposed to highly variable and unknown cocktail of chemicals and radiations. Although individual chemicals are typically present at low concentrations, they can interact with each other resulting in additive or potentially synergistic mixture effects. This was also observed with products obtained by radiation actions such as sunlight or electromagnetic fields that can change the effects of chemicals, such as pesticides, and metal trace elements on health. Concomitant presence of various pesticides and their transformation products adds further complexity to chemical risk assessment since chronic inflammation is a key step for cancer promotion. Degradation of a parent molecule can produce several by-products which can trigger various toxic effects with different impacts on health and environment. For instance, the cocktail of sunlight irradiated sulcotrione pesticide has a greater cytotoxicity and genotoxicity than parent molecule, sulcotrione, and questions about the impact of photochemical process on environment. Adjuvants were shown to modify the biological features of pesticides. Addition of other elements, metals or biological products, can differently enhance cell toxicity of pesticides or electromagnetic radiations suggesting a synergy in living organisms. Electromagnetic fields spreading, pesticide by-products and mixtures monitoring become greater for environmental contamination evaluations.

  12. Complementary use of life cycle assessment and risk assessment for engineered nanomaterials: Lessons learned from chemicals?

    DEFF Research Database (Denmark)

    Grieger, Khara D.; Laurent, Alexis; Miseljic, Mirko

    2013-01-01

    Successful strategies to handle the potential health and environmental risks of engineered nanomaterials (ENM) often rely upon the well-established frameworks of life cycle assessment (LCA) and risk assessment (RA). However, current research and specific guidance on how to actually apply these two...... scientific research efforts have taken into account some key lessons learned from past experiences with chemicals at the same time that many key challenges remain to applying these frameworks to ENM. In that setting, two main proposed approaches to use LCA and RA together for ENM are identified: i) LC...

  13. A Novel Approach: Chemical Relational Databases, and the Role of the ISSCAN Database on Assessing Chemical Carcinogenity

    Science.gov (United States)

    Mutagenicity and carcinogenicity databases are crucial resources for toxicologists and regulators involved in chemicals risk assessment. Until recently, existing public toxicity databases have been constructed primarily as "look-up-tables" of existing data, and most often did no...

  14. Ecotoxicological assessments and the setting of limit values for chemicals in the environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The Committee on the Setting of Limit Values for Chemicals held its first open conference in Denmark in March 1992 at Mogenstrup Kro, Zealand. The conference proceedings were entitled `Risk Management and Risk Assessment in Different Sectors in Denmark`. The conference focused on risk assessment and the setting of limit values for chemicals in connection with human exposure to chemicals. The conference held in January 1996, which is covered by the present proceedings, dealt with the exposure of the environment to chemicals and the state-of-the-art as well as perspectives of ecotoxicological research. Special emphasis was placed on the illustration and discussion of the problems that have to be solved in order to secure satisfactory levels of protection of soil and aquatic environments in connection with exposure to chemicals. Also, problems connected with exposure through the atmosphere were discussed and exemplified by the work on the setting of limit values for tropospheric ozone. Furthermore, the global problems pertaining to what is believed to be the greenhouse effect and the degradation of the stratospheric ozone layer as well as the damage to crops caused by ozone were mentioned. (au)

  15. Chemical Modifications of Starch: Microwave Effect

    Directory of Open Access Journals (Sweden)

    Kamila Lewicka

    2015-01-01

    Full Text Available This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation are discussed. Properties of microwave radiation and its impact on starch (with particular regard to modifications described in literature are characterized.

  16. Assessing preferential flow by simultaneously injecting nanoparticle and chemical tracers

    KAUST Repository

    Subramanian, S. K.

    2013-01-01

    The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do. We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests. If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability.

  17. ORGANIZATIONAL ASSESSMENT: EFFECTIVENESS VS. EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Ilona Bartuševičienė

    2013-06-01

    Full Text Available Purpose – Organizational assessment has always been the key element of the discussion among scientists as well as business people. While managers are striving for better performance results, scientists are reaching for best ways to evaluate the organization. One of the most common ways to assess the performance of the entity is to measure the effectiveness or the efficiency of the organization. Those two concepts might look synonymous, yet as the findings revealed they have a distinct meaning. The purpose of this article is to reveal those differences and explore organizational assessment within effectiveness and efficiency plane. Design/methodology/approach – Scientific literature analysis, comparative and summarization methods will be used during the research to better understand the challenges of the issue. Findings – Effectiveness and efficiency are exclusive performance measures, which entities can use to assess their performance. Efficiency is oriented towards successful input transformation into outputs, where effectiveness measures how outputs interact with the economic and social environment. Research limitations/implications –In some cases effectiveness concept is being used to reflect overall performance of the organization, since it is a broader concept compared to the efficiency. It gets challenging to explore the efficiency factor if it is included under effectiveness assessment. Practical implications – The assessment of the organizational performance helps companies to improve their reports, assures smoother competition in the global market and creates a sustainable competitive advantage. Originality/Value – The paper revealed that organization can be assessed either within effectiveness or efficiency perspective. Organization striving for excellent performance should be effective and efficient, yet as the findings revealed, inefficient, yet effective organization can still survive yet at a high cost. Keywords

  18. Evaluation of EU Risk assessments Existing Chemicals (EC Regulation 793/93)

    NARCIS (Netherlands)

    Bodar CWM; Berthault F; Bruijn JHM de; Leeuwen CJ van; Pronk MEJ; Vermeire TG; CSR

    2002-01-01

    An evaluation was performed on the first group (41) of completed risk assessments for chemicals of the EU priority lists (Existing Chemicals; EC Regulation 793/93). The evaluation focussed on the conclusions of the risk assessments. The EU risk assessment process detected a high number of substance

  19. Toward an integrated assessment of the ecological and chemical status of European river basins.

    Science.gov (United States)

    von der Ohe, Peter C; De Deckere, Eric; Prüss, Andrea; Muñoz, Isabel; Wolfram, Georg; Villagrasa, Marta; Ginebreda, Antonio; Hein, Michaela; Brack, Werner

    2009-01-01

    Here, recommendations to improve ecological and chemical status assessments in accordance with the European Water Framework Directive (WFD) are made on the basis of experience gained from the MODELKEY project database, linking existing biological and chemical monitoring data of 3 case study river basins (Elbe, Scheldt, and Llobregat). The data analysis within and across river basins revealed major obstacles to be tackled, including scarcity of matching ecological and chemical monitoring sites for cause-effect relationships as well as a general lack of stressor-specific metrics for single biological quality elements (BQE) to enable a comprehensive risk assessment of all predominant stressors, including toxicity. An example of such a metric, which is recommended for the BQE of benthic macroinvertebrates, is the trait-based species-at-risk index (SPEAR) that correlated well with a respective measure for toxic stress, referred to as toxic units, based on simple mixture toxicity concepts. Surprisingly, the assessment of chemical status of a total of 695 monitoring sites for 2000 to 2004 showed that environmental quality standards (EQSs) were exceeded for at least 1 of the currently 41 priority pollutants (PPs) in 92% to 98% of the cases in all 3 of the river basins, which, according to definition, indicates potential effects on ecological status. A comparison of compliance with EQSs for 41 PPs with a respective effect threshold (derived for benthic macroinvertebrates) revealed that the rather conservative concept of chemical status is most likely not protective in all cases. Furthermore, to account for the many other compounds that are detected frequently in European surface waters and that may also have ecotoxicological effects, we introduced a provisional predicted no-effect concentration that is in accordance with the EQS methodology and is suggested to identify potential emerging compounds for which no or insufficient toxicity data exist. In conclusion, this study

  20. From incremental to fundamental substitution in chemical alternatives assessment

    DEFF Research Database (Denmark)

    Fantke, Peter; Weber, Roland; Scheringer, Martin

    2015-01-01

    to similarity in chemical structures and, hence, similar hazard profiles between phase-out and substitute chemicals, leading to a rather incremental than fundamental substitution. A hampered phase-out process, the lack of implementing Green Chemistry principles in chemicals design, and lack of Sustainable...... Chemistry aspects in industrial processes design constitute additional challenges. We illustrate the various challenges in the process of phasing out and successfully substituting hazardous chemicals in consumer products and provide guiding principles for addressing these challenges. We propose...

  1. Evaluating uncertainties in an integrated approach for chemical risk assessment under REACH: more certain decisions?

    OpenAIRE

    Vermeire, T.G.

    2009-01-01

    This thesis concentrates on uncertainty and variability in the risk assessment methodology for industrial chemicals as applied within the current regulatory framework for industrial chemicals in Europe, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals). The methodological approaches discussed address the risk assessment for both humans and the environment. The aim of this thesis is to investigate in what way the scientific process of risk assessment can improve deci...

  2. Grouping chemicals for health risk assessment: A text mining-based case study of polychlorinated biphenyls (PCBs).

    Science.gov (United States)

    Ali, Imran; Guo, Yufan; Silins, Ilona; Högberg, Johan; Stenius, Ulla; Korhonen, Anna

    2016-01-22

    As many chemicals act as carcinogens, chemical health risk assessment is critically important. A notoriously time consuming process, risk assessment could be greatly supported by classifying chemicals with similar toxicological profiles so that they can be assessed in groups rather than individually. We have previously developed a text mining (TM)-based tool that can automatically identify the mode of action (MOA) of a carcinogen based on the scientific evidence in literature, and it can measure the MOA similarity between chemicals on the basis of their literature profiles (Korhonen et al., 2009, 2012). A new version of the tool (2.0) was recently released and here we apply this tool for the first time to investigate and identify meaningful groups of chemicals for risk assessment. We used published literature on polychlorinated biphenyls (PCBs)-persistent, widely spread toxic organic compounds comprising of 209 different congeners. Although chemically similar, these compounds are heterogeneous in terms of MOA. We show that our TM tool, when applied to 1648 PubMed abstracts, produces a MOA profile for a subgroup of dioxin-like PCBs (DL-PCBs) which differs clearly from that for the rest of PCBs. This suggests that the tool could be used to effectively identify homogenous groups of chemicals and, when integrated in real-life risk assessment, could help and significantly improve the efficiency of the process.

  3. Environmental management of assembled chemical weapons assessment program.

    Energy Technology Data Exchange (ETDEWEB)

    Frey, G.; Mohrman, G.; Templin, B. R.

    1999-05-07

    Environmental planning and management was an integral part of the ACWA Program planning process. To ensure that environmental protection issues could be addressed expeditiously and not delay the demonstrations, the PMACWA scaled the technology demonstrations such that simplified regulatory processes and existing research and development facilities could be used. The use of enclosed facilities for the demonstrations prevents any uncontrolled discharges to the environment and made it possible to conduct environmental assessments relatively quickly. The PMACWA also arranged for public briefings to ease any community concerns over the operations with chemical weapons. These steps precluded regulatory and community resistance to the ACWA activities. The cooperation of the regulators and stakeholders has been a key element in enabling the ACWA Program to move with the speed that it has to date. Technology demonstrations are currently underway and are scheduled to be completed in late May 1999. The data collected during these demonstrations will be used to prepare and submit a summary report to Congress by August 1999. The challenge continues for the ACWA management to guide the demonstrations to completion and to plan for possible pilot testing. As the scale of the ACWA facilities increase in size, the ease of reduced regulatory processes and environmental analyses will no longer be possible. However, the PMACWA will continue to explore all paths through the environmental process to speed the ACWA program to its goals while at the same time ensuring adequate protection of public health and safety and of the environment.

  4. Survey on methodologies in the risk assessment of chemical exposures in emergency response situations in Europe

    DEFF Research Database (Denmark)

    Heinälä, Milla; Gundert-Remy, Ursula; Wood, Maureen Heraty

    2013-01-01

    A scientifically sound assessment of the risk to human health resulting from acute chemical releases is the cornerstone for chemical incident prevention, preparedness and response. Although the general methodology to identify acute toxicity of chemicals has not substantially changed in the last....../corrosive chemicals will remain serious risks also in future the development of plausible scenarios for potential emerging risks is also needed. This includes risks from new mixtures and chemicals (e.g. nanoparticles)....

  5. Impacts of a clay plaster on indoor air quality assessed using chemical and sensory measurements

    DEFF Research Database (Denmark)

    Darling, Erin K.; Cros, Clement J.; Wargocki, Pawel;

    2012-01-01

    Passive removal materials (PRMs) are building materials or furnishings that effectively control indoor pollution without substantial formation of chemical byproducts and without an energy penalty. Recent studies have suggested that clay might be an effective PRM for ozone. To assess clay wall...... plaster as a PRM for improving air quality by controlling ozone, perceived air quality (PAQ) was determined in the presence of eight combinations of an emitting and reactive pollutant source (new carpet), clay plaster applied to gypsum wallboard, and chamber air with and without ozone. A panel of 24 human...... subjects assessed air quality in twin 30m3 chambers using a continuous acceptability scale. Air samples were collected immediately prior to panel assessment to quantify concentrations of C5–C10 saturated n-aldehydes and two aromatic aldehydes that are commonly produced by reaction of ozone with carpet...

  6. Non-chemical stressors and cumulative risk assessment: an overview of current initiatives and potential air pollutant interactions.

    Science.gov (United States)

    Lewis, Ari S; Sax, Sonja N; Wason, Susan C; Campleman, Sharan L

    2011-06-01

    Regulatory agencies are under increased pressure to consider broader public health concerns that extend to multiple pollutant exposures, multiple exposure pathways, and vulnerable populations. Specifically, cumulative risk assessment initiatives have stressed the importance of considering both chemical and non-chemical stressors, such as socioeconomic status (SES) and related psychosocial stress, in evaluating health risks. The integration of non-chemical stressors into a cumulative risk assessment framework has been largely driven by evidence of health disparities across different segments of society that may also bear a disproportionate risk from chemical exposures. This review will discuss current efforts to advance the field of cumulative risk assessment, highlighting some of the major challenges, discussed within the construct of the traditional risk assessment paradigm. Additionally, we present a summary of studies of potential interactions between social stressors and air pollutants on health as an example of current research that supports the incorporation of non-chemical stressors into risk assessment. The results from these studies, while suggestive of possible interactions, are mixed and hindered by inconsistent application of social stress indicators. Overall, while there have been significant advances, further developments across all of the risk assessment stages (i.e., hazard identification, exposure assessment, dose-response, and risk characterization) are necessary to provide a scientific basis for regulatory actions and effective community interventions, particularly when considering non-chemical stressors. A better understanding of the biological underpinnings of social stress on disease and implications for chemical-based dose-response relationships is needed. Furthermore, when considering non-chemical stressors, an appropriate metric, or series of metrics, for risk characterization is also needed. Cumulative risk assessment research will benefit

  7. Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

    DEFF Research Database (Denmark)

    Rafique, Rashad; Poulsen, Tjalfe; Nizami, Abdul-Sattar

    2010-01-01

    -treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 degrees C-150 degrees C). Results showed that thermo-chemical pretreatment has high effect...

  8. Chemical Munitions Search & Assessment-An evaluation of the dumped munitions problem in the Baltic Sea

    Science.gov (United States)

    Bełdowski, Jacek; Klusek, Zygmunt; Szubska, Marta; Turja, Raisa; Bulczak, Anna I.; Rak, Daniel; Brenner, Matthias; Lang, Thomas; Kotwicki, Lech; Grzelak, Katarzyna; Jakacki, Jaromir; Fricke, Nicolai; Östin, Anders; Olsson, Ulf; Fabisiak, Jacek; Garnaga, Galina; Nyholm, Jenny Rattfelt; Majewski, Piotr; Broeg, Katja; Söderström, Martin; Vanninen, Paula; Popiel, Stanisław; Nawała, Jakub; Lehtonen, Kari; Berglind, Rune; Schmidt, Beata

    2016-06-01

    Chemical Munitions Search & Assessment (CHEMSEA) project has performed studies on chemical weapon (CW) detection, sediment pollution and spreading as well as biological effects of chemical warfare agents (CWAs) dumped in the Baltic Sea. Results suggest that munitions containing CWAs are more scattered on the seafloor than suspected, and previously undocumented dumpsite was discovered in Gdansk Deep. Pollution of sediments with CWA degradation products was local and close to the detected objects; however the pollution range was larger than predicted with theoretical models. Bottom currents observed in the dumpsites were strong enough for sediment re-suspension, and contributed to the transport of polluted sediments. Diversity and density of the faunal communities were poor at the dumping sites in comparison to the reference area, although the direct effects of CWA on benthos organisms were difficult to determine due to hypoxic or even anoxic conditions near the bottom. Equally, the low oxygen might have affected the biological effects assessed in cod and caged blue mussels. Nonetheless, both species showed significantly elevated molecular and cellular level responses at contaminated sites compared to reference sites.

  9. Historical Exposures to Chemicals at the Rocky Flats Nuclear Weapons Plant: A Pilot Retrospective Exposure Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Janeen Denise [Univ. of New Mexico, Albuquerque, NM (United States)

    1999-02-01

    In a mortality study of white males who had worked at the Rocky Flats Nuclear Weapons Plant between 1952 and 1979, an increased number of deaths from benign and unspecified intracranial neoplasms was found. A case-control study nested within this cohort investigated the hypothesis that an association existed between brain tumor death and exposure to either internally deposited plutonium or external ionizing radiation. There was no statistically significant association found between estimated radiation exposure from internally deposited plutonium and the development of brain tumors. Exposure by job or work area showed no significant difference between the cohort and the control groups. An update of the study found elevated risk estimates for (1) all lymphopoietic neoplasms, and (2) all causes of death in employees with body burdens greater than or equal to two nanocuries of plutonium. There was an excess of brain tumors for the entire cohort. Similar cohort studies conducted on worker populations from other plutonium handling facilities have not yet shown any elevated risks for brain tumors. Historically, the Rocky Flats Nuclear Weapons Plant used large quantities of chemicals in their production operations. The use of solvents, particularly carbon tetrachloride, was unique to Rocky Flats. No investigation of the possible confounding effects of chemical exposures was done in the initial studies. The objectives of the present study are to (1) investigate the history of chemical use at the Rocky Flats facility; (2) locate and analyze chemical monitoring information in order to assess employee exposure to the chemicals that were used in the highest volume; and (3) determine the feasibility of establishing a chemical exposure assessment model that could be used in future epidemiology studies.

  10. Chemical photoallergy: photobiochemical mechanisms, classification, and risk assessments.

    Science.gov (United States)

    Onoue, Satomi; Seto, Yoshiki; Sato, Hideyuki; Nishida, Hayato; Hirota, Morihiko; Ashikaga, Takao; Api, Anne Marie; Basketter, David; Tokura, Yoshiki

    2017-01-01

    Chemical photosensitivity can be elicited by exposure of the skin to various pharmaceutical substances, foods, cosmetics and other environmental chemicals, followed by exposure to sunlight. There are at least three types of chemical photosensitivity, i.e., photoirritancy (narrowly defined as phototoxicity), photogenotoxicity and photoallergenicity, and their clinical characteristics and mechanisms are quite different. Concerns about chemical photoallergy is increasing, and various studies have been made to clarify the photobiochemical characteristics of photoallergens and the mechanisms involved. Various methodologies, including in silico prediction models, photochemical assay systems, and in vitro phototoxicity prediction tools, have been developed to predict the photoallergenic potential of chemicals over the past few years. The aim of this manuscript is to review the clinical characteristics, pathogenetic mechanisms and photobiochemical features of photoallergens, with special emphasis on the current status about development of screening systems for predicting photoallergenic potential of chemicals.

  11. Integrated environmental risk assessment and whole-process management system in chemical industry parks.

    Science.gov (United States)

    Shao, Chaofeng; Yang, Juan; Tian, Xiaogang; Ju, Meiting; Huang, Lei

    2013-04-19

    Chemical industry parks in China are considered high-risk areas because they present numerous risks that can damage the environment, such as pollution incidents. In order to identify the environmental risks and the principal risk factors in these areas, we have developed a simple physical model of a regional environmental risk field (ERF) using existing dispersal patterns and migration models. The regional ERF zoning was also conducted and a reference value for diagnostic methods was developed to determine risk-acceptable, risk-warning, and risk-mitigation zones, which can provide a risk source layout for chemical industry parks. In accordance with the environmental risk control requirements, this study focused on the three stages of control and management of environmental risk and established an environmental risk management system including risk source identification and assessment, environmental safety planning, early risk warning, emergency management, assessment of environmental effects, and environmental remediation of pollution accidents. By using this model, the environmental risks in Tianjin Binhai New Area, the largest chemical industry park in China, were assessed and the environmental risk zoning map was drawn, which suggested the existence of many unacceptable environmental risks in this area. Thus, relevant suggestions have been proposed from the perspective of the adjustment of risk source layout, intensified management of environmental risk control and so on.

  12. Integrated Environmental Risk Assessment and Whole-Process Management System in Chemical Industry Parks

    Directory of Open Access Journals (Sweden)

    Lei Huang

    2013-04-01

    Full Text Available Chemical industry parks in China are considered high-risk areas because they present numerous risks that can damage the environment, such as pollution incidents. In order to identify the environmental risks and the principal risk factors in these areas, we have developed a simple physical model of a regional environmental risk field (ERF using existing dispersal patterns and migration models. The regional ERF zoning was also conducted and a reference value for diagnostic methods was developed to determine risk-acceptable, risk-warning, and risk-mitigation zones, which can provide a risk source layout for chemical industry parks. In accordance with the environmental risk control requirements, this study focused on the three stages of control and management of environmental risk and established an environmental risk management system including risk source identification and assessment, environmental safety planning, early risk warning, emergency management, assessment of environmental effects, and environmental remediation of pollution accidents. By using this model, the environmental risks in Tianjin Binhai New Area, the largest chemical industry park in China, were assessed and the environmental risk zoning map was drawn, which suggested the existence of many unacceptable environmental risks in this area. Thus, relevant suggestions have been proposed from the perspective of the adjustment of risk source layout, intensified management of environmental risk control and so on.

  13. Brief communication: the ecosystem perspective in ecotoxicology as a way forward for the ecological risk assessment of chemicals.

    Science.gov (United States)

    De Laender, Frederik; Janssen, Colin R

    2013-07-01

    One of the objectives of the European Union (EU) ecological risk assessment of chemicals (ERA) is to derive maximum environmental concentrations that are not expected to cause adverse ecological effects. To this end, related EU directives list protection goals as well as guidelines that should be used to reach these goals. It is generally accepted that the individual-level endpoints on which these guidelines are based do not correspond to the listed population- and ecosystem-level protection goals. In this article, we identify 5 research topics that are key to bridging this gap: 1) the refinement of population-level effects and recovery rates by explicitly taking into account competition and 2) predation, 3) the assessment of chemical effects on biodiversity, 4) the assessment of chemical stress on ecosystem functions and services, and 5) the quantification of the effects of chemical mixtures. In addition, we illustrate why an ecosystem perspective is needed to address these topics and to inform the risk assessment process. We propose the use of existing ecotoxicological community, food web, and ecosystem models to tackle these issues and discuss why new models are needed to predict chemical effects on biodiversity.

  14. Using Physiologically-Based Pharmacokinetic Models to Incorporate Chemical and Non-Chemical Stressors into Cumulative Risk Assessment: A Case Study of Pesticide Exposures

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2012-05-01

    Full Text Available Cumulative risk assessment has been proposed as an approach to evaluate the health risks associated with simultaneous exposure to multiple chemical and non-chemical stressors. Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD models can allow for the inclusion and evaluation of multiple stressors, including non-chemical stressors, but studies have not leveraged PBPK/PD models to jointly consider these disparate exposures in a cumulative risk context. In this study, we focused on exposures to organophosphate (OP pesticides for children in urban low-income environments, where these children would be simultaneously exposed to other pesticides (including pyrethroids and non-chemical stressors that may modify the effects of these exposures (including diet. We developed a methodological framework to evaluate chemical and non-chemical stressor impacts on OPs, utilizing an existing PBPK/PD model for chlorpyrifos. We evaluated population-specific stressors that would influence OP doses or acetylcholinesterase (AChE inhibition, the relevant PD outcome. We incorporated the impact of simultaneous exposure to pyrethroids and dietary factors on OP dose through the compartments of metabolism and PD outcome within the PBPK model, and simulated combinations of stressors across multiple exposure ranges and potential body weights. Our analyses demonstrated that both chemical and non-chemical stressors can influence the health implications of OP exposures, with up to 5-fold variability in AChE inhibition across combinations of stressor values for a given OP dose. We demonstrate an approach for modeling OP risks in the presence of other population-specific environmental stressors, providing insight about co-exposures and variability factors that most impact OP health risks and contribute to children’s cumulative health risk from pesticides. More generally, this framework can be used to inform cumulative risk assessment for any compound impacted by

  15. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals

    Directory of Open Access Journals (Sweden)

    Huixiao Hong

    2016-03-01

    Full Text Available Endocrine disruptors such as polychlorinated biphenyls (PCBs, diethylstilbestrol (DES and dichlorodiphenyltrichloroethane (DDT are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest and the molecular descriptors calculated from two-dimensional structures by Mold2 software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69% and external validations using 22 chemicals (balanced accuracy of 71%. Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed.

  16. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals.

    Science.gov (United States)

    Hong, Huixiao; Shen, Jie; Ng, Hui Wen; Sakkiah, Sugunadevi; Ye, Hao; Ge, Weigong; Gong, Ping; Xiao, Wenming; Tong, Weida

    2016-03-25

    Endocrine disruptors such as polychlorinated biphenyls (PCBs), diethylstilbestrol (DES) and dichlorodiphenyltrichloroethane (DDT) are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest) and the molecular descriptors calculated from two-dimensional structures by Mold² software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69%) and external validations using 22 chemicals (balanced accuracy of 71%). Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence) in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed.

  17. Interactions of physical, chemical, and biological weather calling for an integrated approach to assessment, forecasting, and communication of air quality.

    Science.gov (United States)

    Klein, Thomas; Kukkonen, Jaakko; Dahl, Aslög; Bossioli, Elissavet; Baklanov, Alexander; Vik, Aasmund Fahre; Agnew, Paul; Karatzas, Kostas D; Sofiev, Mikhail

    2012-12-01

    This article reviews interactions and health impacts of physical, chemical, and biological weather. Interactions and synergistic effects between the three types of weather call for integrated assessment, forecasting, and communication of air quality. Today's air quality legislation falls short of addressing air quality degradation by biological weather, despite increasing evidence for the feasibility of both mitigation and adaptation policy options. In comparison with the existing capabilities for physical and chemical weather, the monitoring of biological weather is lacking stable operational agreements and resources. Furthermore, integrated effects of physical, chemical, and biological weather suggest a critical review of air quality management practices. Additional research is required to improve the coupled modeling of physical, chemical, and biological weather as well as the assessment and communication of integrated air quality. Findings from several recent COST Actions underline the importance of an increased dialog between scientists from the fields of meteorology, air quality, aerobiology, health, and policy makers.

  18. Guidance for risk assessment of chemicals for children

    NARCIS (Netherlands)

    Wolterink G; Engelen JGM van; Raaij MTM van; SIR

    2007-01-01

    Every day humans are exposed to chemicals, either from food and/or non-food sources, such as consumer products. In regulatory toxicology, recent attention has focussed on the possible differences between children and adults with respect to susceptibility and exposure to chemicals. The present RIVM r

  19. Models for risk assessment of reactive chemicals in aquatic toxicology

    NARCIS (Netherlands)

    Freidig, Andreas Peter

    2001-01-01

    A quantitative structure property relationship (QSPR) for a,b-unsaturated carboxylates (mainly acrylates and methacrylates) was established in chapter 2. Chemical reaction rate constants were measured for 12 different chemicals with three different nucleophiles, namely H 2 O, OH - and glutathione (G

  20. Toward refined environmental scenarios for ecological risk assessment of down-the-drain chemicals in freshwater environments.

    Science.gov (United States)

    Franco, Antonio; Price, Oliver R; Marshall, Stuart; Jolliet, Olivier; Van den Brink, Paul J; Rico, Andreu; Focks, Andreas; De Laender, Frederik; Ashauer, Roman

    2017-03-01

    Current regulatory practice for chemical risk assessment suffers from the lack of realism in conventional frameworks. Despite significant advances in exposure and ecological effect modeling, the implementation of novel approaches as high-tier options for prospective regulatory risk assessment remains limited, particularly among general chemicals such as down-the-drain ingredients. While reviewing the current state of the art in environmental exposure and ecological effect modeling, we propose a scenario-based framework that enables a better integration of exposure and effect assessments in a tiered approach. Global- to catchment-scale spatially explicit exposure models can be used to identify areas of higher exposure and to generate ecologically relevant exposure information for input into effect models. Numerous examples of mechanistic ecological effect models demonstrate that it is technically feasible to extrapolate from individual-level effects to effects at higher levels of biological organization and from laboratory to environmental conditions. However, the data required to parameterize effect models that can embrace the complexity of ecosystems are large and require a targeted approach. Experimental efforts should, therefore, focus on vulnerable species and/or traits and ecological conditions of relevance. We outline key research needs to address the challenges that currently hinder the practical application of advanced model-based approaches to risk assessment of down-the-drain chemicals. Integr Environ Assess Manag 2017;13:233-248. © 2016 SETAC.

  1. Chemical and biological risk assessment of chronic exposure to PAH contaminated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Means, J.; McMillin, D.; Kondapi, N. [Louisiana State Univ., Baton Rouge, LA (United States)

    1995-12-31

    Chronically contaminated sediments represent a long-term source of mixtures of contaminants, exposing aquatic ecosystems to PAH through desorption and bioaccumulation. Chronic toxicity assessments must address potential of these bond contaminants. Environmental impacts and ecological health hazards of sediment-bound normal, alkylated and heterocyclic aromatic hydrocarbons are functions of their entry into aquatic food webs and are controlled by both abiotic and biotic factors. Laboratory and field microcosm exposures of fish and invertebrates were conducted followed by assessments of effects using chemical analysis and biomarkers of potential genotoxic effects. Chemical analysis of accumulated residues of 62 individual PAH were conducted in oysters, Crassostrea virginica exposed to PAH contaminated sediments in the field. The rates and equilibrium bioaccumulation constants for each were determined. Fish were exposed to the same contaminated sediments in laboratory and field exposures. Measurements of ethoxy-resorufin-o-deethylase activity induction as well as alterations in the expression of the p53 tumor suppressor gene were performed on exposed fish liver samples. EROD activities were increased significantly relative to unexposed and laboratory/field control sediment-exposed fish, however, the responses of individuals were highly variable. Fundulus grandis or Gambusia affinis, exposed to contaminated sediments in the laboratory, revealed changes in the expression of the p53 tumor suppressor gene. The degree to which mutations within the gene occurred was assessed using PCR followed by measurement of single stranded DNA polymorphisms using gel electrophoresis chromatography.

  2. Chemical Composition and Antibacterial Effects of

    Directory of Open Access Journals (Sweden)

    SS Saei Dehkordi

    2009-10-01

    Full Text Available Introduction & Objective: Rosmarinus officinalis L. as a member of the Lamiaceae family and lysozyme as a natural antibacterial agent is important in food microbiology, because of its characteristics. The aim of the present study was to determine the chemical composition and anti-listerial activity of Rosmarinus officinalis essential oil (REO alone and in combination with lysozyme for enhancement of anti-listerial activity of both substances. Materials & Methods: Rosmarinus officinalis L. was purchased from a local grocery store at Shahrekord and was identified by the Institute of Medicinal Plants, ACECR. The air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus to obtain essential oil and yielded oil was analyzed by GC/MS. Antibacterial activity (on basis of Minimum Inhibitory Concentration (MIC of REO was studied separately and in combination with unheated lysozyme (L and heat-treated lysozyme (HTL on Listeria monocytogenes at different pH (5, 6 and 7 by a micro-broth dilution assay. The collected data were analyzed by SPSS software. Results: In the current study, 98.05% of constituents of the essential oil were identified. The major components were α-pinene (14.06%, 1,8-cineole (13.62%, verbenone (11.2%, camphor (10.51%, borneol (7.3%, 3-octanone (7.02%, camphene (5.46% and linalool (5.07%. The inhibitory action of REO was stronger at lower pH especially 5 (MIC=225 μg/mL. Inhibition by L at pH 5 was 640 μg/mL but no inhibition was seen at pH 7. HTL resulted in more effective inhibition than L, especially at pH 5 and heat-treatment 80˚C (MIC: 160 μg/mL. Conclusion: Combination of L + REO and particularly HTL + REO was led to enhancement of bacterial inhibition. It was concluded that REO by the identified chemical composition was effective alone or in combination with L or HTL on Listeria monocytogenes as a food-borne pathogen.

  3. SOIL QUALITY ASSESSMENT BASED ON CHEMICAL, ENZYMATIC AND BACTERIOLOGICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sofia-Paulina BALAURE

    2012-01-01

    Full Text Available This study highlights the problem of soil pollution as the result of human activities. Soil pollutans may be either chemicals or biological in nature. microbial enzymatic activities are often proposed as indicators of environmental stress. The soil samples were submitted by chemical, microbiological and enzymatic analyses. Chemical analyses were been made for determinating the heavy metals. Heavy metals from the forest soil were represented by Cu, Zn, Mn, Ni, Pb, Cd and Cr. To evaluate the concentration in heavy metals from the filtrate, we used a acetylene-nitrous oxide flame atomic absorption spectrophotometry. Potential dehydrogenase activity, the only indicator of the possible sources of pollution, excluded the presence of either chemical or biological pollution. The number of bacteria involved in the biogeochemical cycle of nitrogen in the analyzed soil indicated a high efficiency regarding the mineralization of the organic residues of plant and animal origin.

  4. The Assessment of Hedge Effectiveness

    Directory of Open Access Journals (Sweden)

    Cristina BUNEA-BONTAS

    2012-04-01

    Full Text Available Earnings volatility can be a significant source of concern for a company, putting pressure on its capital base and share price. Prudent management of the company’s exposure to different risks typically involves hedging solutions. Hedging is important for corporate risk management, involving reducing the exposure of the company to specific risks. The aim of this paper is to examine the basic requirements for assessing the hedge effectiveness, this being a vital stage in applying hedge accounting, that gives the possibility to assess if the companies match the timing of the gains and losses of hedged items and their hedging derivatives. The article identifies some difficulties encountered by companies and choices that they must make in assessing hedge effectiveness.

  5. Cytologic Effects of Air Force Chemicals

    Science.gov (United States)

    1980-11-01

    amounts of methylated guanine residues in the DNA. The DNA samples were hydrolyzed and chromatographed using high pressure liquid chromatography ( HPLC ...induced in freshly isolated lymphocytes by four chemicals, 4NQO, MMS, HN2 and mitomycin C (MMC). The differences in DRS are probably due to the chemical

  6. Risk assessment and toxicology databases for health effects assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lu, P.Y.; Wassom, J.S. [Oak Ridge National Laboratory, TN (United States)

    1990-12-31

    Scientific and technological developments bring unprecedented stress to our environment. Society has to predict the results of potential health risks from technologically based actions that may have serious, far-reaching consequences. The potential for error in making such predictions or assessment is great and multiplies with the increasing size and complexity of the problem being studied. Because of this, the availability and use of reliable data is the key to any successful forecasting effort. Scientific research and development generate new data and information. Much of the scientific data being produced daily is stored in computers for subsequent analysis. This situation provides both an invaluable resource and an enormous challenge. With large amounts of government funds being devoted to health and environmental research programs and with maintenance of our living environment at stake, we must make maximum use of the resulting data to forecast and avert catastrophic effects. Along with the readily available. The most efficient means of obtaining the data necessary for assessing the health effects of chemicals is to utilize applications include the toxicology databases and information files developed at ORNL. To make most efficient use of the data/information that has already been prepared, attention and resources should be directed toward projects that meticulously evaluate the available data/information and create specialized peer-reviewed value-added databases. Such projects include the National Library of Medicine`s Hazardous Substances Data Bank, and the U.S. Air Force Installation Restoration Toxicology Guide. These and similar value-added toxicology databases were developed at ORNL and are being maintained and updated. These databases and supporting information files, as well as some data evaluation techniques are discussed in this paper with special focus on how they are used to assess potential health effects of environmental agents. 19 refs., 5 tabs.

  7. Radiological and chemical assessment of phosphate rocks in some countries

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, U., E-mail: ugurc@ktu.edu.tr [Karadeniz Technical University, Department of Physics, Trabzon (Turkey); Baltas, H. [Rize University, Department of Physics, Rize (Turkey); Tabak, A. [Rize University, Department of Chemistry, Rize (Turkey); Damla, N. [Batman University, Department of Physics, Batman (Turkey)

    2010-10-15

    In this study, the radiological, structural and chemical characterizations of Mardin-Mazidagi phosphate rock, which is an important phosphate fertilizer source in Turkey were investigated and compared to those of several different phosphate rocks of Tunisia, Egypt, Morocco, Algeria and Syria using gamma spectrometry, X-ray diffraction (XRD) and X-ray fluorescence (XRF) measurement techniques. Elemental analysis results of phosphate samples showed that they were mainly composed of CaO, P{sub 2}O{sub 5}, SiO{sub 2}, Al{sub 2}O{sub 3}, SO{sub 3} and Fe{sub 2}O{sub 3}. Elemental concentrations of U and Th were calculated using {sup 226}Ra and {sup 232}Th activity concentrations, respectively. As a result of XRD analysis, the main peaks of the samples were found to be Fluorapatite (Ca{sub 5}(PO{sub 4}){sub 3}F). The radioactivity concentration levels for {sup 226}Ra, {sup 232}Th and {sup 40}K in all phosphate samples ranged from 250 to 1029 Bq kg{sup -1} with a mean of 535 Bq kg{sup -1}, from 5 to 50 Bq kg{sup -1} with a mean of 20 Bq kg{sup -1} and from 117 to 186 Bq kg{sup -1} with a mean of 148 Bq kg{sup -1}, respectively. The computed values of annual effective doses ranged from 0.17 to 0.59 mSv, with a mean value of 0.33 mSv, which is lower than the recommended limit of 1 mSv y{sup -1} by the International Commission on Radiological Protection.

  8. Biochar and hydrochar reactivity assessed by chemical, physical and biological methods

    Science.gov (United States)

    Naisse, Christophe; Alexis, Marie; Wiedner, Katja; Glaser, Bruno; pozzi, Alessandro; Carcaillet, Christopher; Criscuoli, Irene; Miglietta, Franco; Rumpel, Cornelia

    2014-05-01

    Field application of biochar is intended to increase soil carbon (C) storage. The assessment of C storage potential of biochars lacks methods and standard materials. In this study, we compared the chemical reactivity of biochars and hydrochars and their potential mineralisation before and after physical weathering as one possibility to evaluate their environmental stability. We used biochars produced by gasification (GSs) and hydrochars produced by hydrothermal carbonisation (HTCs) produced from three different feedstocks as well as Holocene charcoals (150 and 2000 yr old). Their chemical reactivity was analysed after acid dichromate oxidation and their mineralisation potential after laboratory incubations before and after physical weathering. Our results showed that use of acid dichromate oxidation may allow for differentiation of the reactivity of modern biochars but that chemical reactivity of biochars is poorly suited to assess their environmental residence time because it may change with exposure time in soil. Physical weathering induced a carbon loss and increased biological stability of biochar, while reducing its positive priming effect on native soil organic matter. Model extrapolations based on our data showed that decadal C sequestration potential of GS and HTC is globally equivalent when all losses including those due to priming and physical weathering were taken into account. However, at century scale only GS may have the potential to increase soil C storage.

  9. Tools to prevent process safety events at university research facility - chemical risk assessment and experimental set-up risk assessment

    DEFF Research Database (Denmark)

    Jensen, Niels; Jørgensen, Sten Bay

    2014-01-01

    The article discusses the two forms developed to examine the hazards of the chemicals to be used in the experiments in the experimental setup in the Department of Chemical and Biochemical Engineering of the Technical University of Denmark. A system for the safety assessment of new experimental...

  10. Predictive models for the assessment of occupational exposure to chemicals: A new challenge for employers

    OpenAIRE

    Jan Piotr Gromiec; Małgorzata Kupczewska-Dobecka; Agnieszka Jankowska; Sławomir Czerczak

    2013-01-01

    Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation e...

  11. Chemical effect on diffusion in intermetallic compounds

    Science.gov (United States)

    Chen, Yi-Ting

    With the trend of big data and the Internet of things, we live in a world full of personal electronic devices and small electronic devices. In order to make the devices more powerful, advanced electronic packaging such as wafer level packaging or 3D IC packaging play an important role. Furthermore, ?-bumps, which connect silicon dies together with dimension less than 10 ?m, are crucial parts in advanced packaging. Owing to the dimension of ?-bumps, they transform into intermetallic compound from tin based solder after the liquid state bonding process. Moreover, many new reliability issues will occur in electronic packaging when the bonding materials change; in this case, we no longer have tin based solder joint, instead, we have intermetallic compound ?-bumps. Most of the potential reliability issues in intermetallic compounds are caused by the chemical reactions driven by atomic diffusion in the material; thus, to know the diffusivities of atoms inside a material is significant and can help us to further analyze the reliability issues. However, we are lacking these kinds of data in intermetallic compound because there are some problems if used traditional Darken's analysis. Therefore, we considered Wagner diffusivity in our system to solve the problems and applied the concept of chemical effect on diffusion by taking the advantage that large amount of energy will release when compounds formed. Moreover, by inventing the holes markers made by Focus ion beam (FIB), we can conduct the diffusion experiment and obtain the tracer diffusivities of atoms inside the intermetallic compound. We applied the technique on Ni3Sn4 and Cu3Sn, which are two of the most common materials in electronic packaging, and the tracer diffusivities are measured under several different temperatures; moreover, microstructure of the intermetallic compounds are investigated to ensure the diffusion environment. Additionally, the detail diffusion mechanism was also discussed in aspect of diffusion

  12. Retrospective assessment of exposure to chemicals for a microelectronics and business machine manufacturing facility.

    Science.gov (United States)

    Fleming, Donald A; Woskie, Susan R; Jones, James H; Silver, Sharon R; Luo, Lian; Bertke, Stephen J

    2014-01-01

    A retrospective exposure assessment was performed for use in a health outcomes study of a facility manufacturing circuit boards, business machines, and other equipment during the years 1969-2002. A matrix was developed identifying chemical use by department-year based on company-provided information. Use of six chemical agents (fiberglass, lead, methylene chloride, methyl chloroform, perchloroethylene, and trichloroethylene) and six chemical classes (acid-base, aromatic hydrocarbons, chlorinated hydrocarbons, other hydrocarbons, chlorofluorocarbons, and metals), and general (including unspecified) chemicals was identified. The matrix also contained an assignment for each department-year categorizing the potential for use of chemicals as negligible, intermittent/incidental, or routine. These department-based exposure matrix data were combined with work history data to provide duration of potential chemical use for workers. Negligible, intermittent/incidental or routine extent-of-chemical-use categories comprised 42.6%, 39.4%, and 17.9%, respectively, of total person-years of employment. Cumulative exposure scores were also developed, representing a relative measure of the cumulative extent of potential exposure to the six chemical agents, six chemical classes, and general (including unspecified) chemicals. Additionally, the study period was divided into manufacturing eras showing trends in chemical use, and showing that process use of trichloroethylene and methylene chloride ended in the mid-1980s and the mid-1990s, respectively. This approach may be useful in other assessments addressing a variety of chemicals, and with data constraints common to retrospective chemical exposure studies.

  13. Chemical Effects during Storage of Frozen Foods.

    Science.gov (United States)

    Powrie, W. D.

    1984-01-01

    Discusses (1) characteristics, interrelationships, and distribution of food constituents (including water) in unfrozen food systems; (2) the freezing process; and (3) chemical changes in food during frozen storage. Protein alterations and lipid oxidation are emphasized. (JN)

  14. Chemical leasing business models: a contribution to the effective risk management of chemical substances.

    Science.gov (United States)

    Ohl, Cornelia; Moser, Frank

    2007-08-01

    Chemicals indisputably contribute greatly to the well-being of modern societies. Apart from such benefits, however, chemicals often pose serious threats to human health and the environment when improperly handled. Therefore, the European Commission has proposed a regulatory framework for the Registration, Evaluation and Authorization of Chemicals (REACH) that requires companies using chemicals to gather pertinent information on the properties of these substances. In this article, we argue that the crucial aspect of this information management may be the honesty and accuracy of the transfer of relevant knowledge from the producer of a chemical to its user. This may be particularly true if the application of potentially hazardous chemicals is not part of the user's core competency. Against this background, we maintain that the traditional sales concept provides no incentives for transferring this knowledge. The reason is that increased user knowledge of a chemical's properties may raise the efficiency of its application. That is, excessive and unnecessary usage will be eliminated. This, in turn, would lower the amount of chemicals sold and in competitive markets directly decrease profits of the producer. Through the introduction of chemical leasing business models, we attempt to present a strategy to overcome the incentive structure of classical sales models, which is counterproductive for the transfer of knowledge. By introducing two models (a Model A that differs least and a Model B that differs most from traditional sales concepts), we demonstrate that chemical leasing business models are capable of accomplishing the goal of Registration, Evaluation and Authorization of Chemicals: to effectively manage the risk of chemicals by reducing the total quantity of chemicals used, either by a transfer of applicable knowledge from the lessor to the lessee (Model A) or by efficient application of the chemical by the lessor him/herself (Model B).

  15. Estimation methods for bioaccumulation in risk assessment of organic chemicals.

    NARCIS (Netherlands)

    Jager, D.T.; Hamers, T.

    1997-01-01

    The methodology for estimating bioaccumulation of organic chemicals is evaluated. This study is limited to three types of organisms: fish, earthworms and plants (leaf crops, root crops and grass). We propose a simple mechanistic model for estimating BCFs which performs well against measured data. To

  16. Estimation methods for bioaccumulation in risk assessment of organic chemicals

    NARCIS (Netherlands)

    Jager DT; Hamers T; ECO

    1997-01-01

    The methodology for estimating bioaccumulation of organic chemicals is evaluated. This study is limited to three types of organisms: fish, earthworms and plants (leaf crops, root crops and grass). We propose a simple mechanistic model for estimating BCFs which performs well against measured data. To

  17. TSCA Work Plan Chemical Risk Assessment: 1-Bromopropane

    Science.gov (United States)

    1-Bromopropane (CASRN 106-94-5): or 1-BP is a volatile organic chemical that is considered moderately persistent in the environment but does not have the potential to bioaccumulate in fish or other animals. The majority of the 1-BP production volume (~ 47%) is used as a vapor deg...

  18. Risk assessment for benefits analysis: framework for analysis of a thyroid-disrupting chemical.

    Science.gov (United States)

    Axelrad, Daniel A; Baetcke, Karl; Dockins, Chris; Griffiths, Charles W; Hill, Richard N; Murphy, Patricia A; Owens, Nicole; Simon, Nathalie B; Teuschler, Linda K

    Benefit-cost analysis is of growing importance in developing policies to reduce exposures to environmental contaminants. To quantify health benefits of reduced exposures, economists generally rely on dose-response relationships estimated by risk assessors. Further, to be useful for benefits analysis, the endpoints that are quantified must be expressed as changes in incidence of illnesses or symptoms that are readily understood by and perceptible to the layperson. For most noncancer health effects and for nonlinear carcinogens, risk assessments generally do not provide the dose-response functions necessary for economic benefits analysis. This article presents the framework for a case study that addresses these issues through a combination of toxicology, epidemiology, statistics, and economics. The case study assesses a chemical that disrupts proper functioning of the thyroid gland, and considers the benefits of reducing exposures in terms of both noncancer health effects (hypothyroidism) and thyroid cancers. The effects are presumed to be due to a mode of action involving interference with thyroid-pituitary functioning that would lead to nonlinear dose response. The framework integrates data from animal testing, statistical modeling, human data from the medical and epidemiological literature, and economic methodologies and valuation studies. This interdisciplinary collaboration differs from the more typical approach in which risk assessments and economic analyses are prepared independently of one another. This framework illustrates particular approaches that may be useful for expanded quantification of adverse health effects, and demonstrates the potential of such interdisciplinary approaches. Detailed implementation of the case study framework will be presented in future publications.

  19. Risk Assessment for Children Exposed to Beach Sands Impacted by Oil Spill Chemicals.

    Science.gov (United States)

    Black, Jennifer C; Welday, Jennifer N; Buckley, Brian; Ferguson, Alesia; Gurian, Patrick L; Mena, Kristina D; Yang, Ill; McCandlish, Elizabeth; Solo-Gabriele, Helena M

    2016-08-27

    Due to changes in the drilling industry, oil spills are impacting large expanses of coastlines, thereby increasing the potential for people to come in contact with oil spill chemicals. The objective of this manuscript was to evaluate the health risk to children who potentially contact beach sands impacted by oil spill chemicals from the Deepwater Horizon disaster. To identify chemicals of concern, the U.S. Environmental Protection Agency's (EPA's) monitoring data collected during and immediately after the spill were evaluated. This dataset was supplemented with measurements from beach sands and tar balls collected five years after the spill. Of interest is that metals in the sediments were observed at similar levels between the two sampling periods; some differences were observed for metals levels in tar balls. Although PAHs were not observed five years later, there is evidence of weathered-oil oxidative by-products. Comparing chemical concentration data to baseline soil risk levels, three metals (As, Ba, and V) and four PAHs (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and dibenz[a,h]anthracene) were found to exceed guideline levels prompting a risk assessment. For acute or sub-chronic exposures, hazard quotients, computed by estimating average expected contact behavior, showed no adverse potential health effects. For cancer, computations using 95% upper confidence limits for contaminant concentrations showed extremely low increased risk in the 10(-6) range for oral and dermal exposure from arsenic in sediments and from dermal exposure from benzo[a]pyrene and benz[a]anthracene in weathered oil. Overall, results suggest that health risks are extremely low, given the limitations of available data. Limitations of this study are associated with the lack of toxicological data for dispersants and oil-spill degradation products. We also recommend studies to collect quantitative information about children's beach play habits, which are necessary to more

  20. Risk Assessment for Children Exposed to Beach Sands Impacted by Oil Spill Chemicals

    Directory of Open Access Journals (Sweden)

    Jennifer C. Black

    2016-08-01

    Full Text Available Due to changes in the drilling industry, oil spills are impacting large expanses of coastlines, thereby increasing the potential for people to come in contact with oil spill chemicals. The objective of this manuscript was to evaluate the health risk to children who potentially contact beach sands impacted by oil spill chemicals from the Deepwater Horizon disaster. To identify chemicals of concern, the U.S. Environmental Protection Agency’s (EPA’s monitoring data collected during and immediately after the spill were evaluated. This dataset was supplemented with measurements from beach sands and tar balls collected five years after the spill. Of interest is that metals in the sediments were observed at similar levels between the two sampling periods; some differences were observed for metals levels in tar balls. Although PAHs were not observed five years later, there is evidence of weathered-oil oxidative by-products. Comparing chemical concentration data to baseline soil risk levels, three metals (As, Ba, and V and four PAHs (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and dibenz[a,h]anthracene were found to exceed guideline levels prompting a risk assessment. For acute or sub-chronic exposures, hazard quotients, computed by estimating average expected contact behavior, showed no adverse potential health effects. For cancer, computations using 95% upper confidence limits for contaminant concentrations showed extremely low increased risk in the 10−6 range for oral and dermal exposure from arsenic in sediments and from dermal exposure from benzo[a]pyrene and benz[a]anthracene in weathered oil. Overall, results suggest that health risks are extremely low, given the limitations of available data. Limitations of this study are associated with the lack of toxicological data for dispersants and oil-spill degradation products. We also recommend studies to collect quantitative information about children’s beach play habits, which are

  1. Environmental risk assessment of chemicals and nanomaterials--The best foundation for regulatory decision-making?

    Science.gov (United States)

    Syberg, Kristian; Hansen, Steffen Foss

    2016-01-15

    Environmental risk assessment (ERA) is often considered as the most transparent, objective and reliable decision-making tool for informing the risk management of chemicals and nanomaterials. ERAs are based on the assumption that it is possible to provide accurate estimates of hazard and exposure and, subsequently, to quantify risk. In this paper we argue that since the quantification of risk is dominated by uncertainties, ERAs do not provide a transparent or an objective foundation for decision-making and they should therefore not be considered as a "holy grail" for informing risk management. We build this thesis on the analysis of two case studies (of nonylphenol and nanomaterials) as well as a historical analysis in which we address the scientific foundation for ERAs. The analyses show that ERAs do not properly address all aspects of actual risk, such as the mixture effect and the environmentally realistic risk from nanomaterials. Uncertainties have been recognised for decades, and assessment factors are used to compensate for the lack of realism in ERAs. The assessment factors' values were pragmatically determined, thus lowering the scientific accuracy of the ERAs. Furthermore, the default choice of standard assay for assessing a hazard might not always be the most biologically relevant, so we therefore argue that an ERA should be viewed as a pragmatic decision-making tool among several, and it should not have a special status for informing risk management. In relation to other relevant decision-making tools we discuss the use of chemical alternative assessments (CAAs) and the precautionary principle.

  2. Chemical stimulation in unconventional hydrocarbons extraction in the USA: a preliminary environmental risk assessment.

    Science.gov (United States)

    Sutra, Emilie; Spada, Matteo; Burgherr, Peter

    2016-04-01

    While the exploitation of unconventional resources recently shows an extensive development, the stimulation techniques in use in this domain arouse growing public concerns. Often in the shadow of the disputed hydraulic fracturing process, the matrix acidizing is however a complementary or alternative procedure to enhance the reservoir connectivity. Although acidizing processes are widespread within the traditional hydrocarbons sources exploration, the matrix acidizing does not appear to be commonly used in unconventional hydrocarbons formations due to their low permeability. Nonetheless, this process has been recently applied to the Monterey formation, a shale oil play in California. These stimulation fluids are composed by various chemicals, what represents a matter of concern for public as well as for authorities. As a consequence, a risk assessment implying an exposure and toxicity analysis is needed. Focusing on site surface accidents, e.g., leak of a chemical from a storage tank, we develop in this study concentration scenarios for different exposure pathways to estimate the potential environmental risk associated with the use of specific hazardous substances in the matrix acidizing process for unconventional hydrocarbon reservoirs in the USA. Primary, information about the usage of different hazardous substances have been collected in order to extract the most frequently used chemicals. Afterwards, a probabilistic estimation of the environmental risk associated with the use of these chemicals is carried out by comparing the Predicted Environmental Concentrations (PEC) distribution with the Predicted No Effect Concentrations (PNEC) value. The latter is collected from a literature review, whereas the PEC is estimated as probability distribution concentrations in different environmental compartments (e.g., soil) built upon various predefined accident scenarios. By applying a probabilistic methodology for the concentrations, the level at which the used chemicals

  3. Probabilistic safety assessment in the chemical and nuclear industries

    CERN Document Server

    Fullwood, Ralph R

    2000-01-01

    Probabilistic Safety Analysis (PSA) determines the probability and consequences of accidents, hence, the risk. This subject concerns policy makers, regulators, designers, educators and engineers working to achieve maximum safety with operational efficiency. Risk is analyzed using methods for achieving reliability in the space program. The first major application was to the nuclear power industry, followed by applications to the chemical industry. It has also been applied to space, aviation, defense, ground, and water transportation. This book is unique in its treatment of chemical and nuclear risk. Problems are included at the end of many chapters, and answers are in the back of the book. Computer files are provided (via the internet), containing reliability data, a calculator that determines failure rate and uncertainty based on field experience, pipe break calculator, event tree calculator, FTAP and associated programs for fault tree analysis, and a units conversion code. It contains 540 references and many...

  4. An assessment of nondestructive testing technologies for chemical weapons monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, T.T.

    1993-05-01

    The US Department of Energy (DOE), with the US Army Chemical Research, Development and Engineering Center (CRDEC) under the sponsorship of the Defense Nuclear Agency (DNA), completed testing of Nondestructive Evaluation (NDE) technology on live agent systems. The tests were conducted at Tooele Army Depot during August 1992. The Nondestructive Evaluation systems were tested for potential use in verifying chemical treaty requirements. Five technologies, two neutron and three acoustic, were developed at DOE laboratories. Two systems from the United Kingdom (one neutron and one acoustic) were also included in the field trials. All systems tested showed the ability to distinguish among the VX, GB, and Mustard. Three of the systems (two acoustic and one neutron) were used by On-Site Inspection Agency (OSIA) personnel.

  5. Bridging the gap between academic research and regulatory health risk assessment of Endocrine Disrupting Chemicals.

    Science.gov (United States)

    Beronius, Anna; Hanberg, Annika; Zilliacus, Johanna; Rudén, Christina

    2014-12-01

    Regulatory risk assessment is traditionally based primarily on toxicity studies conducted according to standardized and internationally validated test guidelines. However, health risk assessment of endocrine disrupting chemicals (EDCs) is argued to rely on the efficient integration of findings from academic research. The aim of this review was to provide an overview of current developments to facilitate the use of academic research in regulatory risk assessment of chemicals and how certain aspects of study design and reporting are particularly important for the risk assessment process. By bridging the gap between academic research and regulatory health risk assessment of EDCs, scientific uncertainty in risk assessment conclusions can be reduced, allowing for better targeted policy decisions for chemical risk reduction.

  6. International Frameworks Dealing with Human Risk Assessment of Combined Exposure to Multiple Chemicals

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2013-07-01

    Full Text Available The development of harmonised terminology and frameworks for the human risk assessment of combined exposure to multiple chemicals (“chemical mixtures” is an important area for EFSA and a number of activities have already been undertaken, i.e. in the fields of pesticides and contaminants. The first step prior to a risk assessment of combined exposure to multiple chemicals is problem formulation defining the relevant exposure, hazard and population to be considered. In practice, risk assessment of multiple chemicals is conducted using a tiered approach for exposure assessment, hazard assessment and risk characterisation. Higher tiers require increasing knowledge about the group of chemicals under assessment and the tiers can range from tier 0 (default values, data poor situation to tier 3 (full probabilistic models. This scientific report reviews the terminology, methodologies and frameworks developed by national and international agencies for the human risk assessment of combined exposure to multiple chemicals and provides recommendations for future activities at EFSA in this area.

  7. Integration of chemical-specific exposure and pharmacokinetic information with the chemical-agnostic AOP framework to support high throughput risk assessment

    Science.gov (United States)

    Application of the Adverse Outcome Pathway (AOP) framework and high throughput toxicity testing in chemical-specific risk assessment requires reconciliation of chemical concentrations sufficient to trigger a molecular initiating event measured in vitro and at the relevant target ...

  8. Implications of global climate change for the assessment and management of human health risks of chemicals in the natural environment.

    Science.gov (United States)

    Balbus, John M; Boxall, Alistair B A; Fenske, Richard A; McKone, Thomas E; Zeise, Lauren

    2013-01-01

    Global climate change (GCC) is likely to alter the degree of human exposure to pollutants and the response of human populations to these exposures, meaning that risks of pollutants could change in the future. The present study, therefore, explores how GCC might affect the different steps in the pathway from a chemical source in the environment through to impacts on human health and evaluates the implications for existing risk-assessment and management practices. In certain parts of the world, GCC is predicted to increase the level of exposure of many environmental pollutants due to direct and indirect effects on the use patterns and transport and fate of chemicals. Changes in human behavior will also affect how humans come into contact with contaminated air, water, and food. Dietary changes, psychosocial stress, and coexposure to stressors such as high temperatures are likely to increase the vulnerability of humans to chemicals. These changes are likely to have significant implications for current practices for chemical assessment. Assumptions used in current exposure-assessment models may no longer apply, and existing monitoring methods may not be robust enough to detect adverse episodic changes in exposures. Organizations responsible for the assessment and management of health risks of chemicals therefore need to be more proactive and consider the implications of GCC for their procedures and processes.

  9. Teachers' Assessment Literacy and Washback Effect of Assessment

    Directory of Open Access Journals (Sweden)

    Niveen R. M. Elshawa

    2016-07-01

    Full Text Available Assessment literacy, as a term, is not well known in the educational field. This is unfortunate because teachers' assessment knowledge and competence can have an important influence on the way they teach and the way their students learn.  The relationship between the degree of assessment literacy a teacher has and the washback of this type of assessment is not clearly identified, especially in higher education context.  In view of this gap, this article attempts to examine important assessment literacy issues in relation to student learning: definition and importance of assessment literacy, assessment in higher education and assessment practices through reviewing related studies. The review pinpoints the harmful effects of being assessment illiterate for both teachers and students. Keywords: assessment, assessment literacy, student learning, washback

  10. Which chemicals drive biological effects in wastewater and recycled water?

    Science.gov (United States)

    Tang, Janet Y M; Busetti, Francesco; Charrois, Jeffrey W A; Escher, Beate I

    2014-09-01

    Removal of organic micropollutants from wastewater during secondary treatment followed by reverse osmosis and UV disinfection was evaluated by a combination of four in-vitro cell-based bioassays and chemical analysis of 299 organic compounds. Concentrations detected in recycled water were below the Australian Guidelines for Water Recycling. Thus the detected chemicals were considered not to pose any health risk. The detected pesticides in the wastewater treatment plant effluent and partially advanced treated water explained all observed effects on photosynthesis inhibition. In contrast, mixture toxicity experiments with designed mixtures containing all detected chemicals at their measured concentrations demonstrated that the known chemicals explained less than 3% of the observed cytotoxicity and less than 1% of the oxidative stress response. Pesticides followed by pharmaceuticals and personal care products dominated the observed mixture effects. The detected chemicals were not related to the observed genotoxicity. The large proportion of unknown toxicity calls for effect monitoring complementary to chemical monitoring.

  11. Silicon nanowire field-effect chemical sensor

    NARCIS (Netherlands)

    Chen, Songyue

    2011-01-01

    This thesis describes the work that has been done on the project “Design and optimization of silicon nanowire for chemical sensing”, including Si-NW fabrication, electrical/electrochemical modeling, the application as ISFET, and the build-up of Si- NW/LOC system for automatic sample delivery. A nove

  12. Pathogenic effects of the human chemical biofield.

    Science.gov (United States)

    Rumyantsev, S N; Grzeszczuk, J

    1995-07-01

    Organisms release their antigens into the environment. Some antigens are volatile and may pass into the blood of other organisms during respiration. Fetal antigens enter the mother's bloodstream through the placenta. Foreign antigens in the blood can cause various chemical changes and may initiate an immune reaction.

  13. Male Fathead Minnow Urine-Based Metabolomics for Assessing Impacts of Chemical Stressors

    Science.gov (United States)

    We have developed the potential for profiling metabolites in urine from male fathead minnows (Pimephales promelas) to assess chemical exposures, using nuclear magnetic resonance (NMR) spectroscopy. Both one dimensional (1D) and two dimensional (2D) NMR spectroscopy was us...

  14. Organism and population-level ecological models for chemical risk assessment

    Science.gov (United States)

    Ecological risk assessment typically focuses on animal populations as endpoints for regulatory ecotoxicology. Scientists at USEPA are developing models for animal populations exposed to a wide range of chemicals from pesticides to emerging contaminants. Modeled taxa include aquat...

  15. The inadequacies of pre-market chemical risk assessment's toxicity studies-the implications.

    Science.gov (United States)

    Tweedale, Anthony C

    2017-01-01

    Industry provides essentially all the data for most (pre-market) chemical risk assessments (RA); academics study a chemical once it is marketed. For two randomly-chosen high production chemicals, despite new European Union mandates to evaluate all data, just 13% of the herbicide bentazon and 15% of the flame-retardant hexabromocyclododecane's published toxicity studies were found in their pre-market RA, and a systematic review on bentazon concludes it has greater hazards than indicated in its RA. More important, for both, academia's toxicity studies were designated as lower quality than industries were, despite showing hazards at lower doses. The accuracy of industry's test methods is analyzed and found to be replicable but insensitive, thus inaccurate. The synthetic pharmaceutical industry originated them, and by 1983 the Organization for Economic Cooperation & Development mandated their test guidelines (TG) methods be accepted for any new study for pre-market RA. For existing studies, industry's "Klimisch" criterion is universally used to evaluate quality, but it only states that TG studies produce the best data. However, no TG can answer the realistic exposure effect hypotheses of academics; therefore, crucially in pre-market RA, tens of thousands of published experimental findings (increasingly at low dose) are ignored to determine the safe dose. Few appreciate this, so scientific debate on the most accurate elements of toxicity tests is urgently indicated. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Chemical Assessment of White Wine during Fermentation Process

    Directory of Open Access Journals (Sweden)

    Teodora Coldea

    2014-05-01

    Full Text Available There were investigated chemical properties of indigenous white wine varieties (Fetească albă, Fetească regală and Galbenă de Odobeşti during fermentation. The white wine making process took place at Wine Pilot Station of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. We aimed to monitorize the evolution of fermentation process parameters (temperature, alcohol content, and real extract and the quality of the bottled white wine (total acidity, alcohol content, total sulfur dioxide, total dry extract. The results obtained were in accordance to Romanian Legislation.

  17. Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, Robert D.; Hadley, Donald L.; Armstrong, Peter R.; Buck, John W.; Hoopes, Bonnie L.; Janus, Michael C.

    2001-03-01

    Indoor air quality effects on human health are of increasing concern to public health agencies and building owners. The prevention and treatment of 'sick building' syndrome and the spread of air-borne diseases in hospitals, for example, are well known priorities. However, increasing attention is being directed to the vulnerability of our public buildings/places, public security and national defense facilities to terrorist attack or the accidental release of air-borne biological pathogens, harmful chemicals, or radioactive contaminants. The Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System (IA-NBC-HMAS) was developed to serve as a health impact analysis tool for use in addressing these concerns. The overall goal was to develop a user-friendly fully functional prototype Health Modeling and Assessment system, which will operate under the PNNL FRAMES system for ease of use and to maximize its integration with other modeling and assessment capabilities accessible within the FRAMES system (e.g., ambient air fate and transport models, water borne fate and transport models, Physiologically Based Pharmacokinetic models, etc.). The prototype IA-NBC-HMAS is designed to serve as a functional Health Modeling and Assessment system that can be easily tailored to meet specific building analysis needs of a customer. The prototype system was developed and tested using an actual building (i.e., the Churchville Building located at the Aberdeen Proving Ground) and release scenario (i.e., the release and measurement of tracer materials within the building) to ensure realism and practicality in the design and development of the prototype system. A user-friendly "demo" accompanies this report to allow the reader the opportunity for a "hands on" review of the prototype system's capability.

  18. CASCADE - Chemicals as contaminants in the food chain. A network of excellence for research, risk assessment, and education

    Energy Technology Data Exchange (ETDEWEB)

    Oeberg, M.; Haakansson, H. [Karolinska Institutet, Insitute of Environmental Medicine, Stockholm (Sweden); Pongratz, I.; Gustavsson, J.Aa. [Karolinska Institutet, Dept. of Biosciences, Huddinge (Sweden)

    2004-09-15

    Harmful effects of chemical contaminants in food are of major health concern in Europe today. Lack of integration between basic research, risk assessment, and education severely hampers the efforts to reach European excellence in this area. The research activities that are carried out are small in scale and are not well integrated into a coherent structure. To tackle the fragmentation problems and to achieve synergistic effects and full European research potential, the European Commission has initiated a Network of Excellence called CASCADE or ''Chemicals as contaminants in the food chain: a network of excellence for research, risk assessment, and education'' The contract is running for five years and is worth over 14 million with partners from eighteen research centres. The network has the potential and goal to be a world force in knowledge on health issues related to chemical contaminants in food. Focus is on chemical residues that act via and/or interfere with cell regulation at the level of nuclear receptors. The risk assessment integration parts of the network aim to increase the awareness among scientists and others of the need to bring multiple aspects of scientific information into use in risk assessment.

  19. Assessment of genetic and chemical variability in Thymus caramanicus.

    Science.gov (United States)

    Hadian, Javad; Bigdeloo, Mahdi; Nazeri, Vahideh; Khadivi-Khub, Abdollah

    2014-05-01

    Thymus caramanicus is an endemic species grown in Iran with interesting pharmacological and biological properties. In the present work, essential oil compositions and inter-simple sequences repeat (ISSR) markers were used to estimate the relationships among and within seven populations of T. caramanicus, belonging to three provinces in Iran. The studied individuals were distinguished on the basis of ISSR markers and constituents of essential oil. A total of 127 band positions were produced by 12 ISSR primers, of which 105 were found polymorphic with 82.68% polymorphism. Genetic similarity values among individuals ranged between 0.15 and 0.82 which was indicative of a high level of genetic variation. On the basis of their genetic similarities, ISSR analysis allowed to group the samples into two main clusters. One of these included populations originated from Kerman and Isfahan provinces, and the other cluster consists of populations from Semnan province. Chemical compounds of essential oils were found variable in the various individuals and all samples were principally composed of phenolic constituents (carvacrol and/or thymol). As a consequence, the plants were classified into two major chemotypes including carvacrol and thymol/carvacrol. A relationship between genetic and chemical variability and geographic distribution has been observed in studied populations of T. caramanicus.

  20. Role of Metabolomics in Environmental Chemical Exposure and Risk Assessment

    Science.gov (United States)

    The increasing demand for the reduction, replacement, and refinement of the use of animal models in exposure assessments has stimulated the pursuit of alternative methods. This has included not only the use of the in vitro systems (e.g., cell cultures) in lieu of in vivo whole an...

  1. ASSESSING CHEMICAL HAZARDS AT THE PLUTONIUM FINISHING PLANT (PFP) FOR PLANNING FUTURE D&D

    Energy Technology Data Exchange (ETDEWEB)

    HOPKINS, A.M.; KLOS, D.B.; MINETT, M.J.

    2007-01-25

    This paper documents the fiscal year (FY) 2006 assessment to evaluate potential chemical and radiological hazards associated with vessels and piping in the former plutonium process areas at Hanford's Plutonium Finishing Plant (PFP). Evaluations by PFP engineers as design authorities for specific systems and other subject-matter experts were conducted to identify the chemical hazards associated with transitioning the process areas for the long-term layup of PFP before its eventual final decontamination and decommissioning (D and D). D and D activities in the main process facilities were suspended in September 2005 for a period of between 5 and 10 years. A previous assessment conducted in FY 2003 found that certain activities to mitigate chemical hazards could be deferred safely until the D and D of PFP, which had been scheduled to result in a slab-on-grade condition by 2009. As a result of necessary planning changes, however, D and D activities at PFP will be delayed until after the 2009 time frame. Given the extended project and plant life, it was determined that a review of the plant chemical hazards should be conducted. This review to determine the extended life impact of chemicals is called the ''Plutonium Finishing Plant Chemical Hazards Assessment, FY 2006''. This FY 2006 assessment addresses potential chemical and radiological hazard areas identified by facility personnel and subject-matter experts who reevaluated all the chemical systems (items) from the FY 2003 assessment. This paper provides the results of the FY 2006 chemical hazards assessment and describes the methodology used to assign a hazard ranking to the items reviewed.

  2. Hancornia speciosa latex for biomedical applications: physical and chemical properties, biocompatibility assessment and angiogenic activity.

    Science.gov (United States)

    Almeida, Luciane Madureira; Floriano, Juliana Ferreira; Ribeiro, Thuanne Pires; Magno, Lais Nogueira; da Mota, Lígia Souza Lima Silveira; Peixoto, Nei; Mrué, Fátima; Melo-Reis, Paulo; Lino Junior, Ruy de Souza; Graeff, Carlos Frederico de Oliveira; Gonçalves, Pablo José

    2014-09-01

    The latex obtained from Hancornia speciosa is used in folk medicine for treatment of several diseases, such as acne, warts, diabetes, gastritis and inflammation. In this work, we describe the biocompatibility assessment and angiogenic properties of H. speciosa latex and its potential application in medicine. The physical-chemical characterization was carried out following different methodologies (CHN elemental analyses; thermogravimetric analyses and Fourier transform infrared spectroscopy). The biocompatibility was evaluated through cytotoxicity and genotoxicity tests in fibroblast mouse cells and the angiogenic properties were evaluated using the chick chorioallantoic membrane (CAM) assay model. The physical-chemical results showed that the structure of Hancornia speciosa latex biomembrane is very similar to that of Hevea brasiliensis (commercially available product). Moreover, the cytotoxicity and genotoxicity assays showed that H. speciosa latex is biocompatible with life systems and can be a good biomaterial for medical applications. The CAM test showed the efficient ability of H. speciosa latex in neovascularization of tissues. The histological analysis was in accordance with the results obtained in the CAM assay. Our data indicate that the latex obtained from H. speciosa and eluted in water showed significant angiogenic activity without any cytotoxic or genotoxic effects on life systems. The same did not occur with H. speciosa latex stabilized with ammonia. Addition of ammonia does not have significant effects on the structure of biomembranes, but showed a smaller cell survival and a significant genotoxicity effect. This study contributes to the understanding of the potentialities of H. speciosa latex as a source of new phytomedicines.

  3. Effect of Microwave Radiation on Enzymatic and Chemical Peptide Bond Synthesis on Solid Phase

    Directory of Open Access Journals (Sweden)

    Alessandra Basso

    2009-01-01

    Full Text Available Peptide bond synthesis was performed on PEGA beads under microwave radiations. Classical chemical coupling as well as thermolysin catalyzed synthesis was studied, and the effect of microwave radiations on reaction kinetics, beads' integrity, and enzyme activity was assessed. Results demonstrate that microwave radiations can be profitably exploited to improve reaction kinetics in solid phase peptide synthesis when both chemical and biocatalytic strategies are used.

  4. Assessment of kidney stone and prevalence of its chemical compositions.

    Science.gov (United States)

    Pandeya, A; Prajapati, R; Panta, P; Regmi, A

    2010-09-01

    Kidney stone analysis is the test done on the stone which cause problems when they block the flow of urine through or out of the kidneys. The stones cause severe pain and are also associated with morbidity and renal damage. There is also no clear understanding on the relative metabolic composition of renal calculi. Hence, the study is aimed to find out the chemical composition of it which can guide treatment and give information that may prevent more stones from forming. The study was carried out on the stones that had been sent to the department of Biochemistry (n = 99; M = 61; F = 38; Mean age: 33.6 +/- 14.4 years) Approximately 98.9% of stones were composed of oxalate, 95.9% of Calcium, 85.8% of phosphate, 62.6% of Urate, 46.4% of Ammonium and very few percentages of Carbonate.

  5. Effects of incomplete mixing on chemical reactions under flow heterogeneities.

    Science.gov (United States)

    Perez, Lazaro; Hidalgo, Juan J.; Dentz, Marco

    2016-04-01

    Evaluation of the mixing process in aquifers is of primary importance when assessing attenuation of pollutants. In aquifers different hydraulic and chemical properties can increase mixing and spreading of the transported species. Mixing processes control biogeochemical transformations such as precipitation/dissolution reactions or degradation reactions that are fast compared to mass transfer processes. Reactions are local phenomena that fluctuate at the pore scale, but predictions are often made at much larger scales. However, aquifer heterogeities are found at all scales and generates flow heterogeneities which creates complex concentration distributions that enhances mixing. In order to assess the impact of spatial flow heterogeneities at pore scale we study concentration profiles, gradients and reaction rates using a random walk particle tracking (RWPT) method and kernel density estimators to reconstruct concentrations and gradients in two setups. First, we focus on a irreversible bimolecular reaction A+B → C under homogeneous flow to distinguish phenomena of incomplete mixing of reactants from finite-size sampling effects. Second, we analise a fast reversible bimolecular chemical reaction A+B rightleftharpoons C in a laminar Poiseuille flow reactor to determine the difference between local and global reaction rates caused by the incomplete mixing under flow heterogeneities. Simulation results for the first setup differ from the analytical solution of the continuum scale advection-dispersion-reaction equation studied by Gramling et al. (2002), which results in an overstimation quantity of reaction product (C). In the second setup, results show that actual reaction rates are bigger than the obtained from artificially mixing the system by averaging the concentration vertically. - LITERATURE Gramling, C. M.,Harvey, C. F., Meigs, and L. C., (2002). Reactive transport in porous media: A comparison of model prediction with laboratory visualization, Environ. Sci

  6. Life Cycle Assessment for Chemical Agent Resistant Coating.

    Science.gov (United States)

    1996-09-01

    The equipment uses a patented turbine technology to provide high volume low pressure air instead of the traditional method of using normal compressed...Engineer at Battelle (previously employed by Monsanto ), August 10. Nordic Council. 1992. Product Life Cycle Assessment - Principles and Methodology...February, 21 pp. Woody, G. 1995. Telephone conversation between Gene Woody, Supervisor of CARC painting operations Ft. Campbell and Kevin Taylor

  7. Merging Applicability Domains for in Silico Assessment of Chemical Mutagenicity

    Science.gov (United States)

    2014-02-04

    Center for Drug Evaluation and Research. International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for...Human Use (ICH). M7 (2013): Assessment and Control of DNA Reactive (Mutagenic) Impurities in Pharmaceuticals to Limit Potential Carcinogenic Risk...of potentially mutagenic impurities . Regul. Toxicol. Pharmacol. 2013, 67, 39−52. (9) Netzeva, T. I.; Worth, A.; Aldenberg, T.; Benigni, R.; Cronin, M

  8. Feasibility and effectiveness of chemical bile duct embolization for chemical hepatectomy:a preliminary study

    Institute of Scientific and Technical Information of China (English)

    Fu-Yu Li; Ning Li; Li-Sheng Jiang; Jing-Qiu Cheng; Nan-Sheng Cheng; Xing-Wu Wu; Sheng He

    2006-01-01

    BACKGROUND: The high operative risk of hepatectomy for specially located intrahepatic stones is still a problem to be solved. This study was undertaken to investigate the feasibility and effectiveness of chemical bile duct embolization for chemical hepatectomy. METHODS: Oxybenzene or absolute ethanol plus N-butyl-cyanoacrylate was employed for embolization. The feasibility, effectiveness and mechanism of chemical hepatectomy were preliminarily analyzed histologically or by Fas, TIMP-1, TGF-β1, and collagenⅠ. RESULTS:Oxybenzene plus cyanonacrylate can preferably destroy and embolize the intrahepatic biliary duct, leading to the disappearance of hepatocytes in the periphery of embolized lobe and the achievement of effective chemical hepatectomy. The expressions of Fas, TIMP-1 and TGF-β1 in oxybenzene embolism group (88.90±38.10, 619.43± 183.42, 185.22±70.39) and ethanol embolism group (72.39± 29.51, 407.55±134.74, 163.56±51.75) were higher than those of biliary duct-ligated group (26.31±12.07, 195.31±107.67, 74.84±40.73) (P CONCLUSION: The effect of chemical hepatectomy may be achieved by chemical bile duct embolization.

  9. Climate-based archetypes for the environmental fate assessment of chemicals.

    Science.gov (United States)

    Ciuffo, Biagio; Sala, Serenella

    2013-11-15

    Emissions of chemicals have been on the rise for years, and their impacts are greatly influenced by spatial differentiation. Chemicals are usually emitted locally but their impact can be felt both locally and globally, due to their chemical properties and persistence. The variability of environmental parameters in the emission compartment may affect the chemicals' fate and the exposure at different orders of magnitude. The assessment of the environmental fate of chemicals and the inherent spatial differentiation requires the use of multimedia models at various levels of complexity (from a simple box model to complex computational and high-spatial-resolution models). The objective of these models is to support ecological and human health risk assessment, by reducing the uncertainty of chemical impact assessments. The parameterisation of spatially resolved multimedia models is usually based on scenarios of evaluative environments, or on geographical resolutions related to administrative boundaries (e.g. countries/continents) or landscape areas (e.g. watersheds, eco-regions). The choice of the most appropriate scale and scenario is important from a management perspective, as a balance should be reached between a simplified approach and computationally intensive multimedia models. In this paper, which aims to go beyond the more traditional approach based on scale/resolution (cell, country, and basin), we propose and assess climate-based archetypes for the impact assessment of chemicals released in air. We define the archetypes based on the main drivers of spatial variability, which we systematically identify by adopting global sensitivity analysis techniques. A case study that uses the high resolution multimedia model MAPPE (Multimedia Assessment of Pollutant Pathways in the Environment) is presented. Results of the analysis showed that suitable archetypes should be both climate- and chemical-specific, as different chemicals (or groups of them) have different traits

  10. Risk Assessment of New Chemical Substances. Applicability of EXAMS II as an advanced Water Quality Model

    NARCIS (Netherlands)

    de Nijs ACM; Burns LA

    1990-01-01

    In the cluster project "Risk Assessment of New Chemical Substances methods are developed to systematically predict and assess the hazards for man and environment. After the basic screening of a substance has been carried out, a more extensive study can be performed using models adhered to the

  11. 75 FR 55605 - Assessment of Annual Needs for the List I Chemicals Ephedrine, Pseudoephedrine, and...

    Science.gov (United States)

    2010-09-13

    ... using the calculation methodology described in both the 2009 and 2010 Assessment of Annual Needs (74 FR 32954 and 74 FR 60294, respectively). These calculations take into account the criteria that DEA is... Enforcement Administration Assessment of Annual Needs for the List I Chemicals Ephedrine, Pseudoephedrine,...

  12. 76 FR 56809 - Proposed Assessment of Annual Needs for the List I Chemicals Ephedrine, Pseudoephedrine, and...

    Science.gov (United States)

    2011-09-14

    ... methodology described previously in the 2010 and 2011 assessment of annual needs (74 FR 60294 and 75 FR 79407..., Pseudoephedrine, and Phenylpropanolamine for 2012 AGENCY: Drug Enforcement Administration (DEA), Department of... assessment of annual needs for certain List I chemicals ephedrine, pseudoephedrine, and...

  13. EPA Releases Final Risk Assessment for Chemical used for Paint and Coating Removal

    Science.gov (United States)

    WASHINGTON - Today, the U.S. EPA released the final risk assessment for N-Methylpyrrolidone (NMP), a chemical commonly used to remove paint and other coatings. The assessment identified risks to pregnant women and women of childbearing age, who have

  14. Chemical warfare in freshwater. Allelpathic effects of macrophytes on phytoplankton

    NARCIS (Netherlands)

    Mulderij, G.

    2006-01-01

    Aquatic macrophytes can excrete chemical substances into their enviroment and these compounds may inhibit the growth of phytoplankton. This process is defined as allelopathy: one organism has effects on another via the excretion of a (mixture of) chemical substance(s). With laboratory and field expe

  15. Reference field effect transistor based on chemically modified ISFETs

    NARCIS (Netherlands)

    Skowronska-Ptasinska, Maria; Wal, van der Peter D.; Berg, van den Albert; Bergveld, Piet; Sudhölter, Ernst J.R.; Reinhoudt, David N.

    1990-01-01

    Different hydrophobic polymers were used for chemical modification of ion-sensitive field effect transistors (ISFETs) in order to prepare a reference FET (REFET). Chemical attachment of the polymer to the ISFET gate results in a long lifetime of the device. Properties of polyacrylate (polyACE) REFET

  16. Using Mode of Action to Assess Health Risks from Mixtures of Chemical/Physical Agents

    Energy Technology Data Exchange (ETDEWEB)

    Bull, Richard J.; Lei, Xingye C.; Sasser, Lyle B.

    2003-01-20

    Interactions between tumor promoters with differing mechanisms of action were examined in male B6C3F1 mice treated with mixtures of dichloroacetate (DCA), trichloroacetate (TCA), and tetrachloride (CT), each of which acts by a different mode of action. Mice were initiated by vinyl carbamate (VC), and then promoted by DCA, TCA, CT, or the pair-wised combinations of the three compounds. The effect of each treatment or treatment combination on tumor number/animal and tumor size was individually assessed at 18, 24, 30 or 36 weeks of treatment. Dose-related increases in tumor size were observed with 20 & 50 mg/kg CT, but each produced equal number of tumors at 36 weeks with the main distinction being a decrease in tumor latency at the higher dose. Overall TCA treatment produced dose-related increases in tumor number at 36 weeks of treatment. Thus, the lower doses of CT and TCA treatments apparently affected tumor size rather than number. Results with DCA were not as clear as a true maximum tumor number was not clearly observed within the experimental period. Treatment of mice receiving a high dose of TCA (2 g/L of drinking water) combined with varying doses of DCA (0.1, 0.5 and 2 g/L) produced increased numbers of tumors at 24 weeks and 36 weeks. However, at 36 weeks of treatment DCA produced a dose-related decrease in the size of tumors promoted by TCA. The low dose of TCA (0.1 g/L) decreased the number of tumors produced by a high dose of DCA, however, higher doses of TCA produced the same number as observed with DCA alone. Since these two chemicals produce lesions with differing phenotypes, the combination would have been expected to be additive with respect to number, but this was obviously not the case. These data suggest that the induction of liver cancer from mixtures of solvents may have predictable outcomes. The major conclusion is that these interactions are generally no more than additive. It was most interesting to note that additivity was only observed when

  17. Hazard Assessment of Chemical Air Contaminants Measured in Residences

    Energy Technology Data Exchange (ETDEWEB)

    Logue, J.M.; McKone, T.E.; Sherman, M. H.; Singer, B.C.

    2010-05-10

    Identifying air pollutants that pose a potential hazard indoors can facilitate exposure mitigation. In this study, we compiled summary results from 77 published studies reporting measurements of chemical pollutants in residences in the United States and in countries with similar lifestyles. These data were used to calculate representative mid-range and upper bound concentrations relevant to chronic exposures for 267 pollutants and representative peak concentrations relevant to acute exposures for 5 activity-associated pollutants. Representative concentrations are compared to available chronic and acute health standards for 97 pollutants. Fifteen pollutants appear to exceed chronic health standards in a large fraction of homes. Nine other pollutants are identified as potential chronic health hazards in a substantial minority of homes and an additional nine are identified as potential hazards in a very small percentage of homes. Nine pollutants are identified as priority hazards based on the robustness of measured concentration data and the fraction of residences that appear to be impacted: acetaldehyde; acrolein; benzene; 1,3-butadiene; 1,4-dichlorobenzene; formaldehyde; naphthalene; nitrogen dioxide; and PM{sub 2.5}. Activity-based emissions are shown to pose potential acute health hazards for PM{sub 2.5}, formaldehyde, CO, chloroform, and NO{sub 2}.

  18. Incorporating biomarkers in ecological risk assessment of chemical contaminants of soils

    Directory of Open Access Journals (Sweden)

    A. J. Reinecke

    2007-09-01

    Full Text Available Soil is an important but complex natural resource which is increasingly used as sink for chemicals. The monitoring of soil quality and the assessment of risks posed by contaminants have become crucial. This study deals with the potential use of biomarkers in the monitoring of soils and the assessment of risk resulting from contamination. Apart from an overview of the existing literature on biomarkers, the results of various of our field experiments in South African soils are discussed. Biomarkers may have potential in the assessment of risk because they can indicate at an early stage that exposure has taken place and that a toxic response has been initiated. It is therefore expected that early biomarkers will play an increasing role as diagnostic tools for determining exposure to chemicals and the resulting effects. They may have predictive value that can assist in the prevention or minimising of risks. The aim of this study was to investigate the possibilities of using our results on biomarker responses of soil dwelling organisms to predict changes at higher organisational levels (which may have ecological implications. Our recent experimental results on the evaluation of various biomarkers in both the laboratory and the field are interpreted and placed in perspective within the broader framework of response biology. The aim was further to contribute to the development and application of biomarkers in regulatory risk assessment schemes of soils. This critical review of our own and recent literature on biomarkers in ecotoxicology leads to the conclusion that biomarkers can, under certain conditions, be useful tools in risk assessment. Clear relationships between contamination loads in soil organisms and certain biomarker responses were determined in woodlice, earthworms and terrestrial snails. Clear correlations were also established in field experiments between biomarker responses and changes at the population level. This indicated that, in

  19. Coupled near-field and far-field exposure assessment framework for chemicals in consumer products

    DEFF Research Database (Denmark)

    Fantke, Peter; Ernstoff, Alexi; Huang, Lei;

    2016-01-01

    Humans can be exposed to chemicals in consumer products through product use and environmental emissions over the product life cycle. Exposure pathways are often complex, where chemicals can transfer directly from products to humans during use or exchange between various indoor and outdoor...... compartments until sub-fractions reach humans. To consistently evaluate exposure pathways along product life cycles, a flexible mass balance-based assessment framework is presented structuring multimedia chemical transfers in a matrix of direct inter-compartmental transfer fractions. By matrix inversion, we...... quantify cumulative multimedia transfer fractions and exposure pathway-specific product intake fractions defined as chemical mass taken in by humans per unit mass of chemical in a product. Combining product intake fractions with chemical mass in the product yields intake estimates for use in life cycle...

  20. Toxicokinetic models and related tools in environmental risk assessment of chemicals.

    Science.gov (United States)

    Grech, Audrey; Brochot, Céline; Dorne, Jean-Lou; Quignot, Nadia; Bois, Frédéric Y; Beaudouin, Rémy

    2017-02-01

    Environmental risk assessment of chemicals for the protection of ecosystems integrity is a key regulatory and scientific research field which is undergoing constant development in modelling approaches and harmonisation with human risk assessment. This review focuses on state-of-the-art toxicokinetic tools and models that have been applied to terrestrial and aquatic species relevant to environmental risk assessment of chemicals. Both empirical and mechanistic toxicokinetic models are discussed using the results of extensive literature searches together with tools and software for their calibration and an overview of applications in environmental risk assessment. These include simple tools such as one-compartment models, multi-compartment models to physiologically-based toxicokinetic (PBTK) models, mostly available for aquatic species such as fish species and a number of chemical classes including plant protection products, metals, persistent organic pollutants, nanoparticles. Data gaps and further research needs are highlighted.

  1. Effect of chemical degradation on fluxes of reactive compounds

    Directory of Open Access Journals (Sweden)

    J. Rinne

    2011-12-01

    Full Text Available In the analyses of VOC fluxes measured above plant canopies, one usually assumes the flux above canopy to equal the emission at the surface. Thus one assumes the chemical degradation to be much slower than the turbulent transport. We used a stochastic Lagrangian transport model in which the chemical degradation was described as first order decay in order to study the effect of the chemical degradation on above canopy fluxes of chemically reactive species. With the model we explored the sensitivity of the ratio of the above canopy flux to the surface emission on several parameters such as chemical lifetime of the compound, friction velocity, stability, and canopy density. Our results show that friction velocity and chemical lifetime affected the loss during transport the most. The canopy density had a significant effect if the chemically reactive compound was emitted from the forest floor. We used the results of the simulations together with oxidant data measured during HUMPPA-COPEC-2010 campaign at a Scots pine site to estimate the effect of the chemistry on fluxes of three typical biogenic VOCs, isoprene, α-pinene, and β-caryophyllene. Of these, the chemical degradation had a~major effect on the fluxes of the most reactive species β-caryophyllene, while the fluxes of α-pinene were affected during nighttime. For these two compounds representing the mono- and sesquiterpenes groups, the effect of chemical degradation had also a significant diurnal cycle with the highest chemical loss at night. The different day and night time loss terms need to be accounted for, when measured fluxes of reactive compounds are used to reveal relations between primary emission and environmental parameters.

  2. Environmental risk assessment of chemicals and nanomaterials — The best foundation for regulatory decision-making?

    DEFF Research Database (Denmark)

    Syberg, Kristian; Hansen, Steffen Foss

    2016-01-01

    Environmental risk assessment (ERA) is often considered as the most transparent, objective and reliable decision-making tool for informing the risk management of chemicals and nanomaterials. ERAs are based on the assumption that it is possible to provide accurate estimates of hazard and exposure...... and, subsequently, to quantify risk. In this paper we argue that since the quantification of risk is dominated by uncertainties, ERAs do not provide a transparent or an objective foundation for decision-making and they should therefore not be considered as a “holy grail” for informing risk management.......Webuild this thesis on the analysis of two case studies (of nonylphenol and nanomaterials) as well as a historical analysis in which we address the scientific Foundation for ERAs. The analyses show that ERAs do not properly address all aspects of actual risk, such as the mixture effect and the environmentally...

  3. Use of TSHβ:EGFP transgenic zebrafish as a rapid in vivo model for assessing thyroid-disrupting chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Cheng [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); Graduate University of Chinese Academy of Sciences, Beijing (China); Jin, Xia; He, Jiangyan [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); Yin, Zhan, E-mail: zyin@ihb.ac.cn [Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China)

    2012-07-15

    Accumulating evidence indicates that a wide range of chemicals have the ability to interfere with the hypothalamic–pituitary–thyroid (HPT) axis. Novel endpoints should be evaluated in addition to existing methods in order to effectively assess the effects of these chemicals on the HPT axis. Thyroid-stimulating hormone subunit β (TSHβ) plays central regulatory roles in the HPT system. We identified the regulatory region that determines the expression level of zebrafish TSHβ in the anterior pituitary. In the transgenic zebrafish with EGFP driven by the TSHβ promoter, the similar responsive patterns between the expression levels of TSHβ:EGFP and endogenous TSHβ mRNA in the pituitary are observed following treatments with goitrogen chemicals and exogenous thyroid hormones (THs). These results suggest that the TSHβ:EGFP transgenic reporter zebrafish may be a useful alternative in vivo model for the assessment of chemicals interfering with the HPT system. Highlights: ► The promoter of zebrafish TSHβ gene has been identified. ► The stable TSHβ:EGFP transgenic zebrafish reporter germline has been generated. ► The EGFP in the transgenic fish recapitulated the pattern of pituitary TSHβ mRNA. ► The transgenic zebrafish may be an in vivo model for EDC assessment.

  4. Risk management measures for chemicals in consumer products: documentation, assessment, and communication across the supply chain.

    Science.gov (United States)

    Bruinen de Bruin, Yuri; Hakkinen, Pertti Bert; Lahaniatis, Majlinda; Papameletiou, Demosthenes; Del Pozo, Carlos; Reina, Vittorio; Van Engelen, Jacqueline; Heinemeyer, Gerhard; Viso, Anne Catherine; Rodriguez, Carlos; Jantunen, Matti

    2007-12-01

    This paper analyzes the way risk management measures (RMMs) for consumer products have been used to date in authority and industry risk assessments. A working concept for consumer product RMMs is developed, aimed at controlling, limiting or avoiding exposures, and helping to insure the safe use (or handling) of a substance as part of a consumer product. Particular focus is placed on new requirements introduced by REACH (registration, evaluation, and authorization of chemicals). A RMMs categorization approach is also developed, dividing consumer product RMMs into those that are product integrated and those that are communicated to consumers. For each of these categories, RMMs for normal use, accidental use or misuse need to be distinguished. The level of detail for documenting, assessing and communicating RMMs across supply chains can vary, depending on the type of the assessment (tiered approach). Information on RMMs was collected from published sources to demonstrate that a taxonomical approach using standard descriptors for RMMs libraries is needed for effective information exchange across supply chains.

  5. The Treatment Effectiveness Assessment (TEA

    Directory of Open Access Journals (Sweden)

    Ling W

    2013-09-01

    Full Text Available Walter Ling,1 David Farabee,1 Dagmar Liepa,2 Li-Tzy Wu3 1Integrated Substance Abuse Programs, University of California, Los Angeles, CA, 2Valley Care Medical Center, Panorama City, CA, 3Department of Psychiatry and Behavioral Sciences, School of Medicine, Duke University Medical Center, Durham, NC, USA We have been surprised and gratified by the readers’ responses to our article, The Treatment Effectiveness Assessment (TEA: an efficient, patient-centered instrument for evaluating progress in recovery from addiction, which was published in December 2012.1 In the six months since that time, we have received numerous questions and observations about the article, and about the TEA instrument. Respondents were clinicians: physicians, counselors, therapists, nurses; as well as administrators and policy makers.  View original paper by Ling W, Farabee D, Liepa D, Wu LT. 

  6. Chemically modified field effect transistors with nitrite or fluoride selectivity

    NARCIS (Netherlands)

    Antonisse, Martijn M.G.; Snellink-Ruël, Bianca H.M.; Engbersen, Johan F.J.; Reinhoudt, David N.

    1998-01-01

    Polysiloxanes with different types of polar substituents are excellent membrane materials for nitrite and fluoride selective chemically modified field effect transistors (CHEMFETs). Nitrite selectivity has been introduced by incorporation of a cobalt porphyrin into the membrane; fluoride selectivity

  7. The synergistic toxicity of the multiple chemical mixtures: implications for risk assessment in the terrestrial environment.

    Science.gov (United States)

    Chen, Chen; Wang, Yanhua; Qian, Yongzhong; Zhao, Xueping; Wang, Qiang

    2015-04-01

    The combined toxicity of five insecticides (chlorpyrifos, avermectin, imidacloprid, λ-cyhalothrin, and phoxim), two herbicides (atrazine and butachlor) and a heavy metal (cadmium) has been examined with the earthworm acute toxicity test. Toxicological interactions of these chemicals in four, five, six, seven, and eight-component mixtures were studied using the combination-index (CI) equation method. In four-component and five-component mixtures, the synergistic effects predominated at lower effect levels, while the patterns of interactions found in six, seven, and eight-component mixtures displayed synergism. The λ-CY+IMI+BUT+ATR+CPF+PHO combination displayed the most strongly synergistic interaction, with CI values ranging from 0.09 to 0.15. The nature of the interaction changes with the effect level and the relevance of synergistic effects increase with the complexity of the mixture. The CI method was compared with the classical models of concentration addition (CA) and independent action (IA) and we found that the CI method could accurately predict the combined toxicity. The predicted synergism resulted from co-existence of the pesticides and the heavy metal especially at low effect levels may have important implications in risk assessment for the real terrestrial environment.

  8. Applications of contaminant fate and bioaccumulation models in assessing ecological risks of chemicals: A case study for gasoline hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, Matthew; McKone, Thomas E.; Foster, Karen L.; Maddalena, Randy L.; Parkerton, Thomas F.; Mackay, Don

    2004-02-01

    Mass balance models of chemical fate and transport can be applied in ecological risk assessments for quantitative estimation of concentrations in air, water, soil and sediment. These concentrations can, in turn, be used to estimate organism exposures and ultimately internal tissue concentrations that can be compared to mode-of-action-based critical body residues that correspond to toxic effects. From this comparison, risks to the exposed organism can be evaluated. To illustrate the practical utility of fate models in ecological risk assessments of commercial products, the EQC model and a simple screening level biouptake model including three organisms, (a bird, a mammal and a fish) is applied to gasoline. In this analysis, gasoline is divided into 24 components or ''blocks'' with similar environmental fate properties that are assumed to elicit ecotoxicity via a narcotic mode of action. Results demonstrate that differences in chemical properties and mode of entry into the environment lead to profound differences in the efficiency of transport from emission to target biota. We discuss the implications of these results and insights gained into the regional fate and ecological risks associated with gasoline. This approach is particularly suitable for assessing mixtures of components that have similar modes of action. We conclude that the model-based methodologies presented are widely applicable for screening level ecological risk assessments that support effective chemicals management.

  9. Climate-chemical interactions and greenhouse effects of trace gases

    Science.gov (United States)

    Shi, Guang-Yu; Fan, Xiao-Biao

    1994-01-01

    A completely coupled one-dimensional radiative-convective (RC) and photochemical-diffusion (PC) model has been developed recently and used to study the climate-chemical interactions. The importance of radiative-chemical interactions within the troposphere and stratosphere has been examined in some detail. We find that increases of radiatively and/or chemically active trace gases such as CO2, CH4 and N2O have both the direct effects and the indirect effects on climate change by changing the atmospheric O3 profile through their interaction with chemical processes in the atmosphere. It is also found that the climatic effect of ozone depends strongly on its vertical distribution throughout the troposphere and stratosphere, as well on its column amount in the atmosphere.

  10. Risk Assessment for Natural-Hazard Impact on Hazardous Chemical Installations: Workshop Outcome Report

    OpenAIRE

    2016-01-01

    The impact of natural hazards on hazardous installations can cause major chemical accidents. This so-called “Natech” risk is increasing due to industrialisation and climate change. Capacity building in EU Member States, Candidate Countries and EU Neighbourhood Countries on Natech risk required for Natech risk reduction. This report summarises the findings of a training workshop on risk assessment for natural-hazard impact on hazardous chemical installations which the JRC organised in the ...

  11. Chemical Considerations for an Updated National Assessment of Brackish Groundwater Resources.

    Science.gov (United States)

    McMahon, P B; Böhlke, J K; Dahm, K G; Parkhurst, D L; Anning, D W; Stanton, J S

    2016-07-01

    Brackish groundwater (BGW) is increasingly used for water supplies where fresh water is scarce, but the distribution and availability of such resources have not been characterized at the national scale in the United States since the 1960s. Apart from its distribution and accessibility, BGW usability is a function of the chemical requirements of the intended use, chemical characteristics of the resource, and treatment options to make the resource compatible with the use. Here, we discuss relations between these three chemical factors using national-scale examples and local case studies. In a preliminary compilation of BGW data in the United States, five water types accounted for the major-ion composition of 70% of samples. PHREEQC calculations indicate that 57-77% of samples were oversaturated with respect to barite, calcite, or chalcedony. In the study, 5-14% of samples had concentrations of arsenic, fluoride, nitrate, or uranium that exceeded drinking-water standards. In case studies of the potential use of BGW for drinking water, irrigation, and hydraulic fracturing, PHREEQC simulations of a hypothetical treatment process resembling reverse osmosis (RO) showed that BGW had the potential to form various assemblages of mineral deposits (scale) during treatment that could adversely affect RO membranes. Speciation calculations showed that most boron in the irrigation example occurred as boric acid, which has relatively low removal efficiency by RO. Results of this preliminary study indicate that effective national or regional assessments of BGW resources should include geochemical characterizations that are guided in part by specific use and treatment requirements.

  12. Chemical considerations for an updated National assessment of brackish groundwater resources

    Science.gov (United States)

    McMahon, Peter B.; Bohlke, John Karl; Dahm, Katharine; Parkhurst, David L.; Anning, David W.; Stanton, Jennifer S.

    2016-01-01

    Brackish groundwater (BGW) is increasingly used for water supplies where fresh water is scarce, but the distribution and availability of such resources have not been characterized at the national scale in the United States since the 1960s. Apart from its distribution and accessibility, BGW usability is a function of the chemical requirements of the intended use, chemical characteristics of the resource, and treatment options to make the resource compatible with the use. Here, we discuss relations between these three chemical factors using national-scale examples and local case studies. In a preliminary compilation of BGW data in the United States, five water types accounted for the major-ion composition of 70% of samples. PHREEQC calculations indicate that 57–77% of samples were oversaturated with respect to barite, calcite, or chalcedony. In the study, 5–14% of samples had concentrations of arsenic, fluoride, nitrate, or uranium that exceeded drinking-water standards. In case studies of the potential use of BGW for drinking water, irrigation, and hydraulic fracturing, PHREEQC simulations of a hypothetical treatment process resembling reverse osmosis (RO) showed that BGW had the potential to form various assemblages of mineral deposits (scale) during treatment that could adversely affect RO membranes. Speciation calculations showed that most boron in the irrigation example occurred as boric acid, which has relatively low removal efficiency by RO. Results of this preliminary study indicate that effective national or regional assessments of BGW resources should include geochemical characterizations that are guided in part by specific use and treatment requirements.

  13. Undisclosed chemicals--implications for risk assessment: a case study from the mining industry.

    Science.gov (United States)

    Singh, Khareen; Oates, Christopher; Plant, Jane; Voulvoulis, Nikolaos

    2014-07-01

    Many of the chemicals used in industry can be hazardous to human health and the environment, and some formulations can have undisclosed ingredients and hazards, increasing the uncertainty of the risks posed by their use. The need for a better understanding of the extent of undisclosed information in chemicals arose from collecting data on the hazards and exposures of chemicals used in typical mining operations (copper, platinum and coal). Four main categories of undisclosed chemicals were defined (incomplete disclosure; chemicals with unspecific identities; relative quantities of ingredients not stated; and trade secret ingredients) by reviewing material safety data sheet (MSDS) omissions in previous studies. A significant number of chemicals (20% of 957 different chemicals) across the three sites had a range of undisclosed information, with majority of the chemicals (39%) having unspecific identities. The majority of undisclosed information was found in commercially available motor oils followed by cleaning products and mechanical maintenance products, as opposed to reagents critical to the main mining processes. All three types of chemicals had trade secrets, unspecific chemical identities and incomplete disclosures. These types of undisclosed information pose a hindrance to a full understanding of the hazards, which is made worse when combined with additional MSDS omissions such as acute toxicity endpoints (LD50) and/or acute aquatic toxicity endpoints (LC50), as well as inadequate hazard classifications of ingredients. The communication of the hazard information in the MSDSs varied according to the chemical type, the manufacturer and the regulations governing the MSDSs. Undisclosed information can undermine occupational health protection, compromise the safety of workers in industry, hinder risk assessment procedures and cause uncertainty about future health. It comes down to the duty of care that industries have towards their employees. With a wide range of

  14. Chemical extraction to assess the bioavailability of chlorobenzenes in soil with different aging periods

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yang; Wang, Fang; Yang, Xinglun; Liu, Cuiying; Jin, Xin; Jiang, Xin [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Kengara, Fredrick Orori [Maseno Univ. (Kenya). Dept. of Chemistry

    2011-12-15

    Bioavailability is mainly influenced by aging and desorption of contaminants in soil. The purpose of this study was to investigate the desorption kinetics of chlorobenzenes (CBs) in soil and to investigate whether chemical extractions are suitable for the bioavailability assessment of CBs in soil. A soil spiked with CBs and aged for different periods was extracted with Tenax, hydroxypropyl-{beta}-cyclodextrin (HPCD), and butanol to assess the bioavailability of CBs in soil, respectively. Earthworm (Eisenia foetida) accumulation was used as bioassay in parallel experiments to evaluate the chemical extractions. The results showed that desorption of CBs from soil with consecutive Tenax extraction fitted into triphasic kinetics model. Different chemical methods extracted different amounts of CBs over different aging periods. For hexachlorobenzene (HCB), the extraction efficiency was in the order of butanol > Tenax-6h > HPCD extraction, while the order of butanol > HPCD > Tenax-6h extraction for pentachlorobenzene (PeCB). The bioaccumulation by earthworm decreased with increasing aging period and was significantly higher for HCB than for PeCB (p < 0.05). Earthworm accumulated CBs correlated well with all the three chemical extracted CBs. However, HPCD extraction showed the converse extraction tendency with earthworm uptake of CBs. Chemical extraction could be used to assess the bioavailability of contaminants in soil; however, they were method and compound specific. Tenax and butanol extractions were more reliable than HPCD extraction for bioavailability assessment of the tested CBs and the soil used since they showed the consistent extraction tendency with earthworm uptake of CBs.

  15. AB159. Endocrine disrupting chemicals: toxicological risk assessment in vivo and in vitro models

    Science.gov (United States)

    Thuy, Vo Thi Bich; Nguyen Binh, Le Thi; Phuong Oanh, Kim Thi; Van Hai, Nong

    2015-01-01

    In several studies, scientists asserted that many of endocrine disruptors (EDs), which have been involved in developmental, reproductive, neural, immunological, and other problems in wildlife and laboratory animals. Some environmental EDs, such as di-(2-ethylhexyl) phthalate (DEHP), flutamide (Flu), parabens, are used in many products in life and environment. However, the adverse effects caused by EDs can be temporary or permanent and the mechanism(s) through which these chemicals elicit their effects on biological systems of human and animal health is not clearly understood. The specific aim of this study is to evaluate endocrine disrupting chemicals-induced impact on the male or female reproductive system. An attempt is also made to elucidate the impact of these EDs in an in vitro model, i.e., GH3 rat pituitary cell line. A great deal of work has been carried out on the toxicity of phthalate, Flu, parabens in vivo and in vitro models. In brief, studies have been indicated that long-term and short-term exposure to various endocrine disrupting compounds (i.e., DEHP, Flu, parabens) during development stage (i.e., gestation, neonatal, immature, peripubertal) were done to find alternative dysfunctions later in animal life. The development and function of male or female reproductive tract showed many abnormalities, e.g., menstrual cycle irregularities; impaired fertility, endometriosis, and polycystic ovarian syndrome in female or morphological and functional gonadal dysfunction, e.g., infertility and decreased libido, congenital malformations (altered embryonic and fetal intrauterine development) and testicular dysgenesis syndrome in male. In addition, the differential gene expression patterns by microarray analysis following EDs exposure were found, particularly in steroid hormone synthesis, androgen and/or estrogen synthesis, and sex determination-related gene. On the other hand, studies revealed that parabens, a weak estrogenic chemical, exerted their actions on

  16. Getting the chemicals right: addressing inorganics in sustainability assessments of technologies

    DEFF Research Database (Denmark)

    Müller, Nienke; Fantke, Peter

    A main goal of sustainability research is to enable a technological development in industry and elsewhere that ensures that what is produced and how it is produced today does not harm the quality of human or environmental health for present and future generations. As part of current environmental...... sustainability assessments, the toxicity potential of several thousand organic chemicals is included in characterization models within life cycle impact assessment (LCIA). However, many economic production processes involve the use of inorganic chemicals to a large extent, while the related pressure on human...

  17. Low dose effects and non-monotonic dose responses for endocrine active chemicals: Science to practice workshop: Workshop summary

    DEFF Research Database (Denmark)

    Beausoleil, Claire; Ormsby, Jean-Nicolas; Gies, Andreas

    2013-01-01

    A workshop was held in Berlin September 12–14th 2012 to assess the state of the science of the data supporting low dose effects and non-monotonic dose responses (“low dose hypothesis”) for chemicals with endocrine activity (endocrine disrupting chemicals or EDCs). This workshop consisted...

  18. Utilizing toxicogenomic data to understand chemical mechanism of action in risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Vickie S., E-mail: wilson.vickie@epa.gov [National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Keshava, Nagalakshmi [National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW, Washington, DC 20460 (United States); Hester, Susan [National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Segal, Deborah; Chiu, Weihsueh [National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW, Washington, DC 20460 (United States); Thompson, Chad M. [ToxStrategies, Inc., 23501 Cinco Ranch Blvd., Suite G265, Katy, TX 77494 (United States); Euling, Susan Y. [National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW, Washington, DC 20460 (United States)

    2013-09-15

    The predominant role of toxicogenomic data in risk assessment, thus far, has been one of augmentation of more traditional in vitro and in vivo toxicology data. This article focuses on the current available examples of instances where toxicogenomic data has been evaluated in human health risk assessment (e.g., acetochlor and arsenicals) which have been limited to the application of toxicogenomic data to inform mechanism of action. This article reviews the regulatory policy backdrop and highlights important efforts to ultimately achieve regulatory acceptance. A number of research efforts on specific chemicals that were designed for risk assessment purposes have employed mechanism or mode of action hypothesis testing and generating strategies. The strides made by large scale efforts to utilize toxicogenomic data in screening, testing, and risk assessment are also discussed. These efforts include both the refinement of methodologies for performing toxicogenomics studies and analysis of the resultant data sets. The current issues limiting the application of toxicogenomics to define mode or mechanism of action in risk assessment are discussed together with interrelated research needs. In summary, as chemical risk assessment moves away from a single mechanism of action approach toward a toxicity pathway-based paradigm, we envision that toxicogenomic data from multiple technologies (e.g., proteomics, metabolomics, transcriptomics, supportive RT-PCR studies) can be used in conjunction with one another to understand the complexities of multiple, and possibly interacting, pathways affected by chemicals which will impact human health risk assessment.

  19. THE EFFECT OF DRAINAGE ON CHEMICAL ELEMENTS CONTENT OF MARSH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper takes marsh in the Sanjiang Plain as an example in order to research the effect of draining on the chemical elements in marsh. The Sanjiang Ecological Test Station of Mire and Uetland serves as the resarch base. The authors selected soil samples in the Sanjiang Plain (the top and the end of the drain, marsh soil and degeneration marsh soil), mainly analyzed contents of main ions (HCO3-, Cl-, SO42-and NO3-), main heavy metals (Fe, Mn, Znand Cu), nutritive elements (N, P,K), organic matter and pH value. By testing these samples as above, the paper initially researches the effect on chemical elements content by draining by the means of the contrast of chemical elements contents between marsh soil and degenerative marsh soil and different characteristics of marsh soil elements. Results show that a lot of chemical elements had been lost because of draining.

  20. Effects of irrigation efficiency on chemical transport processes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Irrigation practices greatly affect sustainable agriculture development. In this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils, which had significant impact on the environment. Field dye staining experiments were conducted at different soils with various irrigation amount. Image analysis was conducted to study the heterogeneous flow patterns and their relationships with the irrigation efficiency. Irrigation efficiency and its environmental effects were evaluated using various indictors, including application efficiency, deep percolation ratio, storage efficiency, and uniformity. Under the same irrigation condition, soil chemical distributions were more heterogeneous than soil water distributions. The distributions were mainly affected by soil texture, initial soil water content, and irrigation amount. Storage efficiency, irrigation uniformity, and deep percolation ratio increased with irrigation amount. Since the chemical distribution uniformity was lower than the water uniformity, the amount of chemical leaching increased sharply with decrease of irrigation uniformity, which resulted in high environmental risks of groundwater pollution.

  1. White paper on the promotion of an integrated risk assessment concept in European regulatory frameworks for chemicals.

    Science.gov (United States)

    Wilks, M F; Roth, N; Aicher, L; Faust, M; Papadaki, P; Marchis, A; Calliera, M; Ginebreda, A; Andres, S; Kühne, R; Schüürmann, G

    2015-07-15

    The vision of a sustainable and safe use of chemicals to protect human health, preserve the environment and maintain the ecosystem requires innovative and more holistic approaches to risk assessment (RA) in order to better inform decision making. Integrated risk assessment (IRA) has been proposed as a solution to current scientific, societal and policy needs. It is defined as the mutual exploitation of environmental risk assessment (ERA) for human health risk assessment (HHRA) and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process. Extrapolating between species which are relevant for HHRA and ERA requires a detailed understanding of pathways of toxicity/modes of action (MoA) for the various toxicological endpoints. Significant scientific advances, changes in chemical legislation, and increasing environmental consciousness have created a favourable scientific and regulatory environment to develop and promote the concept and vision of IRA. An initial proof of concept is needed to foster the incorporation of IRA approaches into different chemical sectorial regulations and demonstrate their reliability for regulatory purposes. More familiarity and confidence with IRA will ultimately contribute to an overall reduction in in vivo toxicity testing requirements. However, significant progress will only be made if long-term support for MoA-related research is secured. In the short term, further exchange and harmonization of RA terminology, models and methodologies across chemical categories and regulatory agencies will support these efforts. Since societal values, public perceptions and cultural factors are of increasing importance for the acceptance of risk analysis and successful implementation of risk mitigation measures, the integration of socio-economic analysis and socio-behavioural considerations into the risk analysis process may help to produce a more

  2. Bioanalytical and chemical assessment of the disinfection by-product formation potential: role of organic matter.

    Science.gov (United States)

    Farré, Maria José; Day, Sophie; Neale, Peta A; Stalter, Daniel; Tang, Janet Y M; Escher, Beate I

    2013-09-15

    Disinfection by-products (DBP) formed from natural organic matter and disinfectants like chlorine and chloramine may cause adverse health effects. Here, we evaluate how the quantity and quality of natural organic matter and other precursors influence the formation of DBPs during chlorination and chloramination using a comprehensive approach including chemical analysis of regulated and emerging DBPs, total organic halogen quantification, organic matter characterisation and bioanalytical tools. In vitro bioassays allow us to assess the hazard potential of DBPs early in the chain of cellular events, when the DBPs react with their molecular target(s) and activate stress response and defence mechanisms. Given the reactive properties of known DBPs, a suite of bioassays targeting reactive modes of toxic action including genotoxicity and sensitive early warning endpoints such as protein damage and oxidative stress were evaluated in addition to cytotoxicity. Coagulated surface water was collected from three different drinking water treatment plants, along with reverse osmosis permeate from a desalination plant, and DBP formation potential was assessed after chlorination and chloramination. While effects were low or below the limit of detection before disinfection, the observed effects and DBP levels increased after disinfection and were generally higher after chlorination than after chloramination, indicating that chlorination forms higher concentrations of DBPs or more potent DBPs in the studied waters. Bacterial cytotoxicity, assessed using the bioluminescence inhibition assay, and induction of the oxidative stress response were the most sensitive endpoints, followed by genotoxicity. Source waters with higher dissolved organic carbon levels induced increased DBP formation and caused greater effects in the endpoints related to DNA damage repair, glutathione conjugation/protein damage and the Nrf2 oxidative stress response pathway after disinfection. Fractionation studies

  3. Chemical isomeric effects on propanol glassy structures

    CERN Document Server

    Cuello, G J; Bermejo, F J; Cabrillo, C

    2002-01-01

    We have studied the structure of both propanol isomers in their glassy and crystalline states by neutron diffraction. The glass-transition temperatures of 1- and 2-propanol are about 98 and 115 K, respectively and, surprisingly, even larger differences are observed for the melting temperatures of the stable crystals, which are 148 and 185 K, respectively. Their supercooled liquid phases show rather different relaxation spectra, 1-propanol manifesting strong deviations from Debye behavior, whereas 2-propanol shows a far weaker effect. We discuss the spectra obtained for the static structure factor and the static pair correlation function D(r). There is a noticeable difference in the position of the first sharp diffraction peak, which clearly indicates a density change, well correlated with the period of the intermolecular oscillations shown by D(r). (orig.)

  4. Risk managment of complex aquifers contaminated by chemical mixtures : numerical tools and human health risk assessment

    OpenAIRE

    Henri, Christopher

    2015-01-01

    Human impact on groundwater resources has led to a rapid growth of social concerns worldwide owing to an increasing presence of toxic chemicals released in the subsurface. Risk assessment provides the scientific tool needed to quantify the actual thread that these potential hazards pose to human health. Specifically, risk analysis enables decision makers to answer: What can happen? How likely is it to happen? What can be the consequences? Risk assessment is in this context essential. However,...

  5. Incorporating Risk Assessment and Inherently Safer Design Practices into Chemical Engineering Education

    Science.gov (United States)

    Seay, Jeffrey R.; Eden, Mario R.

    2008-01-01

    This paper introduces, via case study example, the benefit of including risk assessment methodology and inherently safer design practices into the curriculum for chemical engineering students. This work illustrates how these tools can be applied during the earliest stages of conceptual process design. The impacts of decisions made during…

  6. Techno-economic assessment of the production of bio-based chemicals from glutamic acid

    NARCIS (Netherlands)

    Lammens, T.M.; Gangarapu, S.; Franssen, M.C.R.; Scott, E.L.; Sanders, J.P.M.

    2012-01-01

    In this review, possible process steps for the production of bio-based industrial chemicals from glutamic acid are described, including a techno-economic assessment of all processes. The products under investigation were those that were shown to be synthesized from glutamic acid on lab-scale, namely

  7. 78 FR 59679 - Antimony Trioxide TSCA Chemical Risk Assessment; Notice of Public Meetings and Opportunity To...

    Science.gov (United States)

    2013-09-27

    ... Scientific Consulting Group (SCG), Inc., has identified a panel of scientific experts to conduct a peer... Chemical Risk Assessment for Antimony Trioxide.'' EPA will hold three peer review meetings by web connect... speakers providing oral comments during any or all of the peer review meetings as discussed in this...

  8. Assessment of heavy metal removal technologies for biowaste by physico-chemical fractionation

    NARCIS (Netherlands)

    Veeken, A.H.M.; Hamelers, H.V.M.

    2003-01-01

    In the Netherlands, the heavy metal content of biowaste-compost frequently exceeds the legal standards for heavy metals. In order to assess heavy metal removal technologies, a physico-chemical fractionation scheme was developed to gain insight into the distribution of heavy metals (Cd, Cu, Pb and Zn

  9. Building a model based on scientific consensus for Life Cycle Impact Assessment of chemicals:

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky; Huijbregts, Mark; Jolliet, Olivier

    2008-01-01

    Achieving consensus among scientists is often a challenge - particularly in model development. In this article we describe a recent scientific consensus-building process for Life Cycle Impact Assessment (LCIA) models applied to chemical emissions - including the strategy, execution, and results...

  10. Assessment of uncertainties in risk analysis of chemical establishments. The ASSURANCE project. Final summary report

    DEFF Research Database (Denmark)

    Lauridsen, K.; Kozine, Igor; Markert, Frank;

    2002-01-01

    This report summarises the results obtained in the ASSURANCE project (EU contract number ENV4-CT97-0627). Seven teams have performed risk analyses for the same chemical facility, an ammonia storage. The EC's Joint Research Centre at Ispra and RisøNational Laboratory co-ordinated the exercise...... on the ranking among the adherents of the probabilistic approach. Breaking down the modelling of both frequencyand consequence assessments into suitably small elements and conducting case studies allowed identifying root causes of uncertainty in the final risk assessments. Large differences were found in both...... the frequency assessments and in the assessment ofconsequences. The report gives a qualitative assessment of the importance to the final calculated risk of uncertainties in assumptions made, in the data and the calculation methods used. This assessment can serve as a guide to areas where, in particular...

  11. Conceptualising the effectiveness of impact assessment processes

    Energy Technology Data Exchange (ETDEWEB)

    Chanchitpricha, Chaunjit, E-mail: chaunjit@g.sut.ac.th [School of Environmental Health, Suranaree University of Technology, 111 University Avenue, Maung District, Nakhon Ratchasima 30000 (Thailand); Bond, Alan, E-mail: alan.bond@uea.ac.uk [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Unit for Environmental Sciences and Management School of Geo and Spatial Sciences, Internal Box 375, North West University (Potchefstroom campus) (South Africa)

    2013-11-15

    This paper aims at conceptualising the effectiveness of impact assessment processes through the development of a literature-based framework of criteria to measure impact assessment effectiveness. Four categories of effectiveness were established: procedural, substantive, transactive and normative, each containing a number of criteria; no studies have previously brought together all four of these categories into such a comprehensive, criteria-based framework and undertaken systematic evaluation of practice. The criteria can be mapped within a cycle/or cycles of evaluation, based on the ‘logic model’, at the stages of input, process, output and outcome to enable the identification of connections between the criteria across the categories of effectiveness. This framework is considered to have potential application in measuring the effectiveness of many impact assessment processes, including strategic environmental assessment (SEA), environmental impact assessment (EIA), social impact assessment (SIA) and health impact assessment (HIA). -- Highlights: • Conceptualising effectiveness of impact assessment processes. • Identification of factors influencing effectiveness of impact assessment processes. • Development of criteria within a framework for evaluating IA effectiveness. • Applying the logic model to examine connections between effectiveness criteria.

  12. Reducing aquatic hazards of industrial chemicals: probabilistic assessment of sustainable molecular design guidelines.

    Science.gov (United States)

    Connors, Kristin A; Voutchkova-Kostal, Adelina M; Kostal, Jakub; Anastas, Paul; Zimmerman, Julie B; Brooks, Bryan W

    2014-08-01

    Basic toxicological information is lacking for the majority of industrial chemicals. In addition to increasing empirical toxicity data through additional testing, prospective computational approaches to drug development aim to serve as a rational basis for the design of chemicals with reduced toxicity. Recent work has resulted in the derivation of a "rule of 2," wherein chemicals with an octanol-water partition coefficient (log P) less than 2 and a difference between the lowest unoccupied molecular orbital and the highest occupied molecular orbital (ΔE) greater than 9 (log P9 eV) are predicted to be 4 to 5 times less likely to elicit acute or chronic toxicity to model aquatic organisms. The present study examines potential reduction of aquatic toxicity hazards from industrial chemicals if these 2 molecular design guidelines were employed. Probabilistic hazard assessment approaches were used to model the likelihood of encountering industrial chemicals exceeding toxicological categories of concern both with and without the rule of 2. Modeling predicted that utilization of these molecular design guidelines for log P and ΔE would appreciably decrease the number of chemicals that would be designated to be of "high" and "very high" concern for acute and chronic toxicity to standard model aquatic organisms and end points as defined by the US Environmental Protection Agency. For example, 14.5% of chemicals were categorized as having high and very high acute toxicity to the fathead minnow model, whereas only 3.3% of chemicals conforming to the design guidelines were predicted to be in these categories. Considerations of specific chemical classes (e.g., aldehydes), chemical attributes (e.g., ionization), and adverse outcome pathways in representative species (e.g., receptor-mediated responses) could be used to derive future property guidelines for broader classes of contaminants.

  13. Health and environmental effects of complex chemical mixtures: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The Office of Health and Environmental Research (OHER) of the Department of Energy supports a broad long-term research program on human health and environmental effects from potential exposure to energy-related complex chemical mixtures. The program seeks basic mechanistic data on the effects of complex mixtures at the cellular, molecular, and whole animal levels to aid in predicting human health effects and seeks ecological data on biological and physical transformations in the mixtures, concentrations of the mixtures in various compartments of the environment, and potential routes for human exposure to these mixtures (e.g., food chain). On June 17-18, 1985, OHER held its First Annual Technical Meeting on the Complex Chemical Mixtures Program in Chicago, IL. The primary purpose of the meeting was to enable principal investigators to report the research status and accomplishments of ongoing complex chemical mixture studies supported by OHER. To help focus future research directions round table discussions were conducted.

  14. Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

    Energy Technology Data Exchange (ETDEWEB)

    Rafique, Rashad; Nizami, Abdul-Sattar; Murphy, Jerry D.; Kiely, Gerard [Department of Civil and Environmental Engineering, University College Cork (Ireland); Poulsen, Tjalfe Gorm [Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University (Denmark); Asam, Zaki-ul-Zaman [Department of Civil Engineering, National University of Ireland Galway (Ireland)

    2010-12-15

    The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 C-150 C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 C). Maximum enhancement is observed at 70 C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 C), with maximum enhancement at 100 C having 28% biogas and 25% methane increase. (author)

  15. In vitro cardiotoxicity assessment of environmental chemicals using an organotypic human induced pluripotent stem cell-derived model.

    Science.gov (United States)

    Sirenko, Oksana; Grimm, Fabian A; Ryan, Kristen R; Iwata, Yasuhiro; Chiu, Weihsueh A; Parham, Frederick; Wignall, Jessica A; Anson, Blake; Cromwell, Evan F; Behl, Mamta; Rusyn, Ivan; Tice, Raymond R

    2017-03-01

    An important target area for addressing data gaps through in vitro screening is the detection of potential cardiotoxicants. Despite the fact that current conservative estimates relate at least 23% of all cardiovascular disease cases to environmental exposures, the identities of the causative agents remain largely uncharacterized. Here, we evaluate the feasibility of a combinatorial in vitro/in silico screening approach for functional and mechanistic cardiotoxicity profiling of environmental hazards using a library of 69 representative environmental chemicals and drugs. Human induced pluripotent stem cell-derived cardiomyocytes were exposed in concentration-response for 30min or 24h and effects on cardiomyocyte beating and cellular and mitochondrial toxicity were assessed by kinetic measurements of intracellular Ca(2+) flux and high-content imaging using the nuclear dye Hoechst 33342, the cell viability marker Calcein AM, and the mitochondrial depolarization probe JC-10. More than half of the tested chemicals exhibited effects on cardiomyocyte beating after 30min of exposure. In contrast, after 24h, effects on cell beating without concomitant cytotoxicity were observed in about one third of the compounds. Concentration-response data for in vitro bioactivity phenotypes visualized using the Toxicological Prioritization Index (ToxPi) showed chemical class-specific clustering of environmental chemicals, including pesticides, flame retardants, and polycyclic aromatic hydrocarbons. For environmental chemicals with human exposure predictions, the activity-to-exposure ratios between modeled blood concentrations and in vitro bioactivity were between one and five orders of magnitude. These findings not only demonstrate that some ubiquitous environmental pollutants might have the potential at high exposure levels to alter cardiomyocyte function, but also indicate similarities in the mechanism of these effects both within and among chemicals and classes.

  16. Potential long-term chemical effects of diesel fuel emissions on a mining environment: A preliminary assessment based on data from a deep subsurface tunnel at Rainer Mesa, Nevada test site

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.; Bourcier, W.L.; Alai, M. [and others

    1995-09-01

    The general purpose of the Yucca Mountain Site Characterization Project (YMSCP) Introduced Materials Task is to understand and predict potential long-term modifications of natural water chemistry related to the construction and operation of a radioactive waste repository that may significantly affect performance of the waste packages. The present study focuses on diesel exhaust. Although chemical information on diesel exhaust exists in the literature, it is either not explicit or incomplete, and none of it establishes mechanisms that might be used to predict long-term behavior. In addition, the data regarding microbially mediated chemical reactions are not well correlated with the abiotic chemical data. To obtain some of the required long-term information, we chose a historical analog: the U12n tunnel at Rainier Mesa, Nevada Test Site. This choice was based on the tunnel`s extended (30-year) history of diesel usage, its geological similarity to Yucca Mountain, and its availability. The sample site within the tunnel was chosen based on visual inspection and on information gathered from miners who were present during tunnel operations. The thick layer of dark deposit at that site was assumed to consist primarily of rock powder and diesel exhaust. Surface samples and core samples were collected with an intent to analyze the deposit and to measure potential migration of chemical components into the rock. X-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy dispersive spectra (EDS) analysis, secondary-ion mass spectrometry (SIMS), and Fourier transform infrared (FTIR) analysis were used to measure both spatial distribution and concentration for the wide variety of chemical components that were expected based on our literature survey.

  17. Application of the Activity Framework for Assessing Aquatic Ecotoxicology Data for Organic Chemicals.

    Science.gov (United States)

    Thomas, Paul; Dawick, James; Lampi, Mark; Lemaire, Philippe; Presow, Shaun; van Egmond, Roger; Arnot, Jon A; Mackay, Donald; Mayer, Philipp; Galay Burgos, Malyka

    2015-10-20

    Toxicological research in the 1930s gave the first indications of the link between narcotic toxicity and the chemical activity of organic chemicals. More recently, chemical activity has been proposed as a novel exposure parameter that describes the fraction of saturation and that quantifies the potential for partitioning and diffusive uptake. In the present study, more than 2000 acute and chronic algal, aquatic invertebrates and fish toxicity data, as well as water solubility and melting point values, were collected from a series of sources. The data were critically reviewed and grouped by mode of action (MoA). We considered 660 toxicity data to be of acceptable quality. The 328 data which applied to the 72 substances identified as MoA 1 were then evaluated within the activity-toxicity framework: EC50 and LC50 values for all three taxa correlated generally well with (subcooled) liquid solubilities. Acute toxicity was typically exerted within the chemical activity range of 0.01-0.1, whereas chronic toxicity was exerted in the range of 0.001-0.01. These results confirm that chemical activity has the potential to contribute to the determination, interpretation and prediction of toxicity to aquatic organisms. It also has the potential to enhance regulation of organic chemicals by linking results from laboratory tests, monitoring and modeling programs. The framework can provide an additional line of evidence for assessing aquatic toxicity, for improving the design of toxicity tests, reducing animal usage and addressing chemical mixtures.

  18. Effective Classroom Assessment for Children's Learning

    Institute of Scientific and Technical Information of China (English)

    黄志红

    2004-01-01

    Formative assessment is a new concept introduced to the English teachers in China by the National English Curriculum (NEC). Its main feature is to provide quick feedback to promote learning and improve teaching, compared with summative assessment. Mostly, formative assessment is implemented during teaching practice. It should be a part of teaching and learning process. So far as it is concerned, teachers play a very important role. They should be able to decide or select what to be assessed and how to assess in classroom teaching. Thus, the focus of this article is to show them the practical ways to reach the goal, i.e. how to implement formative assessment more effectively.

  19. Uptake of chemicals from indoor air: Pathways and health effects

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2016-01-01

    Building occupants are exposed to manufactured chemicals. Exposure in the indoor environment can occur via non-dietary ingestion (e.g. indoor dust), inhalation and dermal absorption including dermal uptake directly from air. The extent of dermal uptake from air has been previously studied...... intake from inhalation. Further experiments have been conducted with nicotine and the results are similar. Some of the SVOCs present indoors may have adverse health effects or are categorized as potential endocrine-disrupting compounds. It has been suggested that the health effects of a chemical may...

  20. Radiation chemical effects of X-rays on liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holroyd, R.A.; Preses, J.M.

    1998-11-01

    This review describes some of the chemical changes induced by photoelectrons which are released in liquids when X-rays are absorbed. Both experimental studies and theory are discussed. In part 1, the basic processes occurring upon absorption of X-rays are described. Parts 2 and 3 deal with hydrocarbon liquids; in part 2 the ion yields, including effects at K-edges, and in part 3, the yields of excited states. Part 4 discusses chemical effects of X-rays in aqueous solutions. The authors end with a summary of future needs and directions.

  1. Assessment of serum biomarkers in rats after exposure to pesticides of different chemical classes

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Virginia C., E-mail: Moser.ginger@epa.gov [Neurotoxicology Branch/Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Stewart, Nicholas; Freeborn, Danielle L. [Neurotoxicology Branch/Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Crooks, James; MacMillan, Denise K. [Analytical Chemistry Research Core/Research Cores Unit, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hedge, Joan M.; Wood, Charles E. [Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); McMahen, Rebecca L. [ORISE fellow, Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Strynar, Mark J. [Human Exposure and Atmospheric Sciences Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Herr, David W. [Neurotoxicology Branch/Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

    2015-01-15

    There is increasing emphasis on the use of biomarkers of adverse outcomes in safety assessment and translational research. We evaluated serum biomarkers and targeted metabolite profiles after exposure to pesticides (permethrin, deltamethrin, imidacloprid, carbaryl, triadimefon, fipronil) with different neurotoxic actions. Adult male Long–Evans rats were evaluated after single exposure to vehicle or one of two doses of each pesticide at the time of peak effect. The doses were selected to produce similar magnitude of behavioral effects across chemicals. Serum or plasma was analyzed using commercial cytokine/protein panels and targeted metabolomics. Additional studies of fipronil used lower doses (lacking behavioral effects), singly or for 14 days, and included additional markers of exposure and biological activity. Biomarker profiles varied in the number of altered analytes and patterns of change across pesticide classes, and discriminant analysis could separate treatment groups from control. Low doses of fipronil produced greater effects when given for 14 days compared to a single dose. Changes in thyroid hormones and relative amounts of fipronil and its sulfone metabolite also differed between the dosing regimens. Most cytokine changes reflected alterations in inflammatory responses, hormone levels, and products of phospholipid, fatty acid, and amino acid metabolism. These findings demonstrate distinct blood-based analyte profiles across pesticide classes, dose levels, and exposure duration. These results show promise for detailed analyses of these biomarkers and their linkages to biological pathways. - Highlights: • Pesticides typical of different classes produced distinct patterns of change in biomarker panels. • Based on the panels used, alterations suggest impacts on immune, metabolism, and homeostasis functions. • Some changes may reflect actions on neurotransmitter systems involved in immune modulation. • Fipronil effects on thyroid and kinetics

  2. Access and use of information resources in assessing health risks from chemical exposure: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    Health risk assessment is based on access to comprehensive information about potentially hazardous agents in question. Relevant information is scattered throughout the literature, and often is not readily accessible. To be useful in assessment efforts, emerging scientific findings, risk assess parameters, and associated data must be compiled and evaluated systemically. The US Environmental Protection Agency (EPA) and Oak Ridge National Laboratory (ORNL) are among the federal agencies heavily involved in this effort. This symposium was a direct response by EPA and ORNL to the expressed needs of individuals involved in assessing risks from chemical exposure. In an effort to examine the state of the risk assessment process, the availability of toxicological information, and the future development and transfer of this information, the symposium provided an excellent cadre of speakers and participants from state and federal agencies, academia and research laboratories to address these topics. This stimulating and productive gathering discussed concerns associated with (1) environmental contamination by chemicals; (2) laws regulating chemicals; (3) information needs and resources; (4) applications; (5) challenges and priorities; and (6)future issues. Individual reports are processed separately for the data bases.

  3. Fate and effects of anthropogenic chemicals in mangrove ecosystems: A review

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Michael, E-mail: lewis.michael@epa.gov [U.S. Environmental Protection Agency, Office of Research and Development, 1 Sabine Island Drive, Gulf Breeze, FL 32561 (United States); Pryor, Rachel; Wilking, Lynn [U.S. Environmental Protection Agency, Office of Research and Development, 1 Sabine Island Drive, Gulf Breeze, FL 32561 (United States)

    2011-10-15

    The scientific literature for fate and effects of non-nutrient contaminant concentrations is skewed for reports describing sediment contamination and bioaccumulation for trace metals. Concentrations for at least 22 trace metals have been reported in mangrove sediments. Some concentrations exceed sediment quality guidelines suggesting adverse effects. Bioaccumulation results are available for at least 11 trace metals, 12 mangrove tissues, 33 mangrove species and 53 species of mangrove-habitat biota. Results are specific to species, tissues, life stage, and season and accumulated concentrations and bioconcentration factors are usually low. Toxicity tests have been conducted with 12 mangrove species and 8 species of mangrove-related fauna. As many as 39 effect parameters, most sublethal, have been monitored during the usual 3 to 6 month test durations. Generalizations and extrapolations for toxicity between species and chemicals are restricted by data scarcity and lack of experimental consistency. This hinders chemical risk assessments and validation of effects-based criteria. - Chemical risk assessments and resource management are restricted by the limited chemical fate and effects database for mangroves.

  4. The synergistic effect of ultrasound and chemical penetration enhancers on chorioamnion mass transport.

    Science.gov (United States)

    Azagury, Aharon; Khoury, Luai; Adato, Yair; Wolloch, Lior; Ariel, Ilana; Hallak, Mordechai; Kost, Joseph

    2015-02-28

    In our previous study we proposed the use of chemical penetration enhancers for noninvasive detection of fetus abnormalities that can also be utilized for direct fetal drug delivery. In an attempt to further increase the mass transport rate across the amniotic membrane, thus shortening the procedure and improving the applicability of the proposed procedure, the effect and mechanism of combining ultrasound exposure with chemical penetration enhancers' application were assessed. The combined effect was evaluated in vitro on post-delivery human amniotic membrane and ex vivo on rat's whole amniotic sac. Ultrasound effect has been assessed by dye experiments using a customized image analysis program. Additional insights of ultrasound effect's mechanism on biological membranes are presented. Previously we have determined that chemical penetration enhancers affect the fetal membranes via two mechanisms termed as 'extractors' and 'fluidizers'. In this study, we found that combining ultrasound with a 'fluidizer' CPE (e.g. bupivacaine) results in a synergistic enhancement (90-fold) of fetal membrane's mass transport, while combining ultrasound with 'extractors' (e.g. ethanol and NMP) results in an antagonistic effect. The combined procedure is faster and gain greater accuracy than the applications of sole chemical penetration enhancers.

  5. Cognitive effects of endocrine-disrupting chemicals in animals.

    Science.gov (United States)

    Schantz, S L; Widholm, J J

    2001-12-01

    A large number of chemical pollutants including phthalates, alkylphenolic compounds, polychlorinated biphenyls and polychlorinated dibenzodioxins, organochlorine pesticides, bisphenol A, and metals including lead, mercury, and cadmium have the ability to disrupt endocrine function in animals. Some of these same chemicals have been shown to alter cognitive function in animals and humans. Because hormonally mediated events play a central role in central nervous system development and function, a number of researchers have speculated that the changes in cognitive function are mediated by the endocrine-like actions of these chemicals. In this paper we review the evidence that cognitive effects of chemicals classified as environmental endocrine disruptors are mediated by changes in hormonal function. We begin by briefly reviewing the role of gonadal steroids, thyroid hormones, and glucocorticoids in brain development and brain function. We then review the endocrine changes and cognitive effects that have been reported for selected endocrine-disrupting chemicals, discuss the evidence for causal relationships between endocrine disruption and cognitive effects, and suggest directions for future research.

  6. Proposals to overcome limitations in the EU chemical risk assessment scheme

    DEFF Research Database (Denmark)

    Trapp, Stefan; Schwartz, S.

    2000-01-01

    The noti®cation of new chemicals in the European Union requires a risk assessment. A Technical Guidance Document (TGD) was prepared for assistance. The TGD proposes QSARs, regressions and models from various sources. Each method has its own range of applicability and its own restrictions. Regress......The noti®cation of new chemicals in the European Union requires a risk assessment. A Technical Guidance Document (TGD) was prepared for assistance. The TGD proposes QSARs, regressions and models from various sources. Each method has its own range of applicability and its own restrictions......, it is shown that in certain cases uptake is underestimated by the model due to processes not considered. This may lead to a wrong security in risk assessment. To overcome these limitations, a set of alternative models with di€erent application ranges should be developed. When no applicable method is available...

  7. Combined use of meio- and macrobenthic indices to assess complex chemical impacts on a stream ecosystem

    Science.gov (United States)

    McKnight, Ursula S.; Sonne, Anne T.; Rasmussen, Jes J.; Traunspurger, Walter; Höss, Sebastian; Bjerg, Poul L.

    2016-04-01

    Ecosystem dynamics (e.g. temperature, inorganic nutrients) and properties (e.g. resilience, robustness), and ecological functions and services depend on the structure and diversity of biological communities, and the fluxes of energy and materials occurring within and across abiotic and biotic boundaries. The close interchange, i.e. multiple feedback loops, between hydrologic and biologic controls is also becoming increasingly evident. Holistic approaches are thus necessary for a robust understanding of ecosystem functioning and subsequent implementation of effective management practices across multiple spatial scales. Groundwater and surface water resources are under pressure from increasing global exploitation and anthropogenic impacts such as contamination by chemicals, leading to a severe degradation of essential ecological functions. Many of the environmental problems we face today have existed for decades; what has changed is our understanding of the key drivers, processes and impacts. The first reporting by European Member States (MS) on the status of their water bodies found that rivers and transitional waters were often in worse condition than lakes and coastal waters. This is not surprising considering that streams integrate all of the diverse stressors found within a catchment (e.g. contaminated sites; diffuse source pollution; water abstraction). The chemical status of a water body is relatively straightforward to assess, defined partly by environmental quality standards on priority substances and partly by additional regulations imposed by individual MS. However, the biological quality elements used for the classification of ecological status are only loosely defined, leaving MS free to develop their own assessment tools. Although useful for the individual MS, it impedes methodological standardization across different ecoregions, thus contributing to inconsistencies and data gaps across Europe. Moreover, despite the unambiguous importance of benthic

  8. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  9. Method of Determining Index Weight of the Assessment of Chemical Reconnaissance Equipment Effectiveness%化学侦察装备效能评估指标权重的确定方法

    Institute of Scientific and Technical Information of China (English)

    宋剑; 林阳

    2015-01-01

    针对海军陆战队遂行两栖作战时化学侦察装备效能评估指标的确定问题,运用层次分析法,建立模型求解指标权重,使用 Yaahp 软件计算结果,并给出了某些化学侦察装备指标的各个子指标的赋权实例。%In order to determine the evaluation index of Marine Corps amphibious combat chemical reconnaissance e‐quipment efficiency ,by using the analytic hierarchy process ,the solving weight index model is established ,and Yaahp soft‐ware calculations are used ,and empowerment examples of each sub‐index of certain chemical reconnaissance equipment index are given .

  10. Chemical and toxicologic assessment of organic contaminants in surface water using passive samplers

    Science.gov (United States)

    Alvarez, D.A.; Cranor, W.L.; Perkins, S.D.; Clark, R.C.; Smith, S.B.

    2008-01-01

    Passive sampling methodologies were used to conduct a chemical and toxicologic assessment of organic contaminants in the surface waters of three geographically distinct agricultural watersheds. A selection of current-use agrochemicals and persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides, were targeted using the polar organic chemical integrative sampler (POCIS) and the semipermeable membrane device passive samplers. In addition to the chemical analysis, the Microtox assay for acute toxicity and the yeast estrogen screen (YES) were conducted as potential assessment tools in combination with the passive samplers. During the spring of 2004, the passive samplers were deployed for 29 to 65 d at Leary Weber Ditch, IN; Morgan Creek, MD; and DR2 Drain, WA. Chemical analysis of the sampler extracts identified the agrochemicals predominantly used in those areas, including atrazine, simazine, acetochlor, and metolachlor. Other chemicals identified included deethylatrazine and deisopropylatrazine, trifluralin, fluoranthene, pyrene, cis- and trans-nonachlor, and pentachloroanisole. Screening using Microtox resulted in no acutely toxic samples. POCIS samples screened by the YES assay failed to elicit a positive estrogenic response. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  11. Cuticle Structure in Relation to Chemical Composition: Re-assessing the Prevailing Model

    Science.gov (United States)

    Fernández, Victoria; Guzmán-Delgado, Paula; Graça, José; Santos, Sara; Gil, Luis

    2016-01-01

    The surface of most aerial plant organs is covered with a cuticle that provides protection against multiple stress factors including dehydration. Interest on the nature of this external layer dates back to the beginning of the 19th century and since then, several studies facilitated a better understanding of cuticular chemical composition and structure. The prevailing undertanding of the cuticle as a lipidic, hydrophobic layer which is independent from the epidermal cell wall underneath stems from the concept developed by Brongniart and von Mohl during the first half of the 19th century. Such early investigations on plant cuticles attempted to link chemical composition and structure with the existing technologies, and have not been directly challenged for decades. Beginning with a historical overview about the development of cuticular studies, this review is aimed at critically assessing the information available on cuticle chemical composition and structure, considering studies performed with cuticles and isolated cuticular chemical components. The concept of the cuticle as a lipid layer independent from the cell wall is subsequently challenged, based on the existing literature, and on new findings pointing toward the cell wall nature of this layer, also providing examples of different leaf cuticle structures. Finally, the need for a re-assessment of the chemical and structural nature of the plant cuticle is highlighted, considering its cell wall nature and variability among organs, species, developmental stages, and biotic and abiotic factors during plant growth. PMID:27066059

  12. Cuticle structure in relation to chemical composition: re-assessing the prevailing model

    Directory of Open Access Journals (Sweden)

    Victoria eFernandez

    2016-03-01

    Full Text Available The surface of most aerial plant organs is covered with a cuticle that provides protection against multiple stress factors including dehydration. Interest on the nature of this external layer dates back to the beginning of the 19th century and since then, several studies facilitated a better understanding of cuticular chemical composition and structure. The prevailing undertanding of the cuticle as a lipidic, hydrophobic layer which is independent from the epidermal cell wall underneath stems from the concept developed by Brongniart and von Mohl during the first half of the 19th century. Such early investigations on plant cuticles attempted to link chemical composition and structure with the existing technologies, and have not been directly challenged for decades. Beginning with a historical overview about the development of cuticular studies, this review is aimed at critically assessing the information available on cuticle chemical composition and structure, considering studies performed with cuticles and isolated cuticular chemical components. The concept of the cuticle as a lipid layer independent from the cell wall is subsequently challenged, based on the existing literature, and on new findings pointing towards the cell wall nature of this layer, also providing examples of different leaf cuticle structures. Finally, the need for a re-assessment of the chemical and structural nature of the plant cuticle is highlighted, considering its cell wall nature and variability among organs, species, developmental stages, and biotic and abiotic factors during plant growth.

  13. Hazard Assessment on Chlorine Distribution Use of Chemical Transportation Risk Index

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Gon [Hanwha Chemical Ulsan Site, Ulsan (Korea, Republic of); Byun, Hun Soo [Chonnam National University, Yeosu (Korea, Republic of)

    2014-12-15

    Chlorine is one of the most produced and most used non-flammable chemical substances in the world even though its toxicity and high reactivity cause the ozone layer depletion. However, in modern life, it is impossible to live a good life without using Chlorine and its derivatives since they are being used as an typical ingredient in more than 40 percent of the manufactured goods including medicines, detergents, deodorant, fungicides, herbicides, insecticides, and plastic, etc. Even if Chlorine has been handled and distributed in various business (small and medium-sized businesses, water purification plants, distribution company, etc.), there have been few researches about its possible health hazard and transportation risks. Accordingly, the purpose of this paper is to make a detailed assessment of Chlorinerelated risks and to model an index of chemicals transportation risks that is adequate for domestic circumstances. The assessment of possible health hazard and transportation risks was made on 13 kinds of hazardous chemicals, including liquid chlorine. This research may be contributed to standardizing the risk assessment of Chlorine and other hazardous chemicals by using an index of transportation risks.

  14. Implementation and student perceptions of e-assessment in a Chemical Engineering module

    Science.gov (United States)

    Sorensen, Eva

    2013-05-01

    This paper describes work carried out at the Department of Chemical Engineering at UCL into the use of e-assessment in a second year module and, in particular, the student perceptions of this mode of assessment. Three quizzes were implemented in Moodle, the first two as formative assessment and the final quiz as summative assessment. The results were very encouraging and practically all students engaged with the process. An online survey was delivered to all students after the module, which showed that the students felt that e-assessment added value to their learning and they would like to see it implemented in other modules. The quizzes were intended to be mainly beneficial to the weaker students as it gave them an opportunity to go over key aspects of the material in their own time. Interestingly, the stronger students were even more in favour of e-learning than the weaker students, for whom the quizzes were originally designed.

  15. Incorporating transgenerational testing and epigenetic mechanisms into chemical testing and risk assessment: A survey of transgenerational responses in environmental chemical studies

    Science.gov (United States)

    A number of environmental chemicals have been shown to alter markers of epigenetic change. Some published multi-generation rodent studies have identified effects on F2 and greater generations after chemical exposures solely to F0 dams, but were not focused on chemical safety. We ...

  16. International issues on human health effects of exposure to chemical mixtures.

    Science.gov (United States)

    Feron, Victor J; Cassee, Flemming R; Groten, John P; van Vliet, Petronella W; van Zorge, Job A

    2002-12-01

    In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a tool in safety evaluation of complex mixtures. A "bottom-up" approach for chemosensory detection of mixtures has recently been presented. Other topics include a method for the safety evaluation of natural flavoring complexes, and an evaluation of the possible health effects of the simultaneous intake of food additives. Examples of issues related to mixtures of airborne chemicals are potential interaction of fine particles and gaseous pollutants in ambient air, nasal cancer associated with inhaled chemical mixtures, and the recommendation of a limit value for volatile organic compounds. Topics of a more strategic nature include studies concerning the public health effects of large airports, and the development of criteria for a harmonized classification of chemical mixtures. This overview illustrates that strategies to tackle the safety evaluation of combined exposures and complex mixtures as well as models facilitating the interpretation of findings in the context of risk assessment of mixtures have become increasingly important. It is true that exposure of humans to chemical mixtures is the rule rather than the exception, and therefore health risk assessments should focus on mixtures and not on single chemicals. It is also true, however, that humans have learned to cope with exposure to huge numbers of chemicals simultaneously (food, water, air, soil, and consumer products). Therefore, in view of limited resources for toxicological research, the focus in toxicology should be

  17. From the exposome to mechanistic understanding of chemical-induced adverse effects.

    Science.gov (United States)

    Escher, Beate I; Hackermüller, Jörg; Polte, Tobias; Scholz, Stefan; Aigner, Achim; Altenburger, Rolf; Böhme, Alexander; Bopp, Stephanie K; Brack, Werner; Busch, Wibke; Chadeau-Hyam, Marc; Covaci, Adrian; Eisenträger, Adolf; Galligan, James J; Garcia-Reyero, Natalia; Hartung, Thomas; Hein, Michaela; Herberth, Gunda; Jahnke, Annika; Kleinjans, Jos; Klüver, Nils; Krauss, Martin; Lamoree, Marja; Lehmann, Irina; Luckenbach, Till; Miller, Gary W; Müller, Andrea; Phillips, David H; Reemtsma, Thorsten; Rolle-Kampczyk, Ulrike; Schüürmann, Gerrit; Schwikowski, Benno; Tan, Yu-Mei; Trump, Saskia; Walter-Rohde, Susanne; Wambaugh, John F

    2017-02-01

    The exposome encompasses an individual's exposure to exogenous chemicals, as well as endogenous chemicals that are produced or altered in response to external stressors. While the exposome concept has been established for human health, its principles can be extended to include broader ecological issues. The assessment of exposure is tightly interlinked with hazard assessment. Here, we explore if mechanistic understanding of the causal links between exposure and adverse effects on human health and the environment can be improved by integrating the exposome approach with the adverse outcome pathway (AOP) concept that structures and organizes the sequence of biological events from an initial molecular interaction of a chemical with a biological target to an adverse outcome. Complementing exposome research with the AOP concept may facilitate a mechanistic understanding of stress-induced adverse effects, examine the relative contributions from various components of the exposome, determine the primary risk drivers in complex mixtures, and promote an integrative assessment of chemical risks for both human and environmental health.

  18. Effect-Based Tools for Monitoring and Predicting the Ecotoxicological Effects of Chemicals in the Aquatic Environment

    Directory of Open Access Journals (Sweden)

    Richard E. Connon

    2012-09-01

    Full Text Available Ecotoxicology faces the challenge of assessing and predicting the effects of an increasing number of chemical stressors on aquatic species and ecosystems. Herein we review currently applied tools in ecological risk assessment, combining information on exposure with expected biological effects or environmental water quality standards; currently applied effect-based tools are presented based on whether exposure occurs in a controlled laboratory environment or in the field. With increasing ecological relevance the reproducibility, specificity and thus suitability for standardisation of methods tends to diminish. We discuss the use of biomarkers in ecotoxicology including ecotoxicogenomics-based endpoints, which are becoming increasingly important for the detection of sublethal effects. Carefully selected sets of biomarkers allow an assessment of exposure to and effects of toxic chemicals, as well as the health status of organisms and, when combined with chemical analysis, identification of toxicant(s. The promising concept of “adverse outcome pathways (AOP” links mechanistic responses on the cellular level with whole organism, population, community and potentially ecosystem effects and services. For most toxic mechanisms, however, practical application of AOPs will require more information and the identification of key links between responses, as well as key indicators, at different levels of biological organization, ecosystem functioning and ecosystem services.

  19. Assessment and control of chemical risk from organic vapors for attendants in a gas station

    Directory of Open Access Journals (Sweden)

    Stephanie Ehmig Santillán

    2015-12-01

    Full Text Available This research comprises monitoring, assessment and recommendations for chemical risk originating from organic vapors (benzene, toluene and xylene of fuel (super and extra gasoline to which attendants at a gas station are exposed. Given the concentration measured of organic vapors (benzene, toluene and xylene the chemical risk to which attendants are exposed in the supply area is acceptable. Control measures are recommended to ensure healthy working conditions for gas station attendants and also to avoid occurrence of occupational diseases in the medium or long term

  20. The effects of chemical propulsion on the environment

    Science.gov (United States)

    Bennett, R. R.; Hinshaw, J. C.; Barnes, M. W.

    This paper seeks to quantify the effects of chemical propulsion exhaust on both the local launch site and the global environments. Four major areas of concern are discussed: the stratospheric ozone, acid rain, toxicity, and the greenhouse effect. The environmental impacts of both solid and liquid rocket propulsion systems are evaluated. The exhaust species and launch profile of the Space Shuttle, which injects the greatest mass of exhaust products into the atmosphere of any current system, are discussed in some detail. Model calculations predict a global stratospheric ozone reduction of about 0.01% due to chemical propulsion. Acid rain due to the HCl in solid rocket exhaust has a small measurable impact on the local environment, with the mortalities of some plants and small fish very near (<2500 ft) the launch site having been documented. Based on history, the handling of potentially toxic species from the use of chemical propulsion systems is manageable. The relative contribution of chemical propulsion to the global CO 2 burden, the increase of which may lead to global warming, is insignificant. It appears that the perturbation to the natural environment caused by chemical propulsion exhaust is very small and manageable, even for the most optimistic projections of future launch rates.

  1. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, D.N.

    1995-01-01

    The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se

  2. Assessing the potential hazard of chemical substances for the terrestrial environment. Development of hazard classification criteria and quantitative environmental indicators.

    Science.gov (United States)

    Tarazona, J V; Fresno, A; Aycard, S; Ramos, C; Vega, M M; Carbonell, G

    2000-03-20

    Hazard assessment constitutes an essential tool in order to evaluate the potential effects of chemical substances on organisms and ecosystems. It includes as a first step, hazard identification, which must detect the potential dangers of the substance (i.e. the kind of effects that the substance may produce), and a second step to quantify each danger and to set the expected dose/response relationships. Hazard assessment plays a key role in the regulation of chemical substances, including pollution control and sustainable development. However, the aquatic environment has largely received more attention than terrestrial ecosystems. This paper presents the extrapolation of several basic concepts from the aquatic to the terrestrial compartment, and suggests possibilities for their regulatory use. Two specific proposals are discussed. The first focuses on the scientific basis of the hazard identification-classification criteria included in the EU regulations and their extrapolation to the terrestrial environment. The second focuses on the OECD programme for environmental indicators and the development of a soil pollution pressure indicator to quantify the potential hazards for the soil compartment and its associated terrestrial ecosystem related to the toxic chemicals applied deliberately (i.e. pesticides) or not (i.e. heavy metals in sludge-based fertilisers; industrial spills) to the soil.

  3. Revision and extension of Eco-LCA metrics for sustainability assessment of the energy and chemical processes.

    Science.gov (United States)

    Yang, Shiying; Yang, Siyu; Kraslawski, Andrzej; Qian, Yu

    2013-12-17

    Ecologically based life cycle assessment (Eco-LCA) is an appealing approach for the evaluation of resources utilization and environmental impacts of the process industries from an ecological scale. However, the aggregated metrics of Eco-LCA suffer from some drawbacks: the environmental impact metric has limited applicability; the resource utilization metric ignores indirect consumption; the renewability metric fails to address the quantitative distinction of resources availability; the productivity metric seems self-contradictory. In this paper, the existing Eco-LCA metrics are revised and extended for sustainability assessment of the energy and chemical processes. A new Eco-LCA metrics system is proposed, including four independent dimensions: environmental impact, resource utilization, resource availability, and economic effectiveness. An illustrative example of comparing assessment between a gas boiler and a solar boiler process provides insight into the features of the proposed approach.

  4. Toxicity tests with crustaceans for detecting sublethal effects of potential endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Wollenberger, Leah

    of effective concentrations (ECx). After having demonstrated that larval development of A. tonsa was a very sensitive endpoint for evaluating effects of chemicals that might interfere with the endocrine system of crustaceans, the larval development test has been applied to two groups of emerging environmental...... of in vitro assays and (sub)chronic copepod tests, as applied in this study, is a valuable tool when screening chemicals suspected to be specifically toxic, in particular, to interfere with the endocrine system. The results of the experimental work as well as the literature survey demonstrated clearly......New and updated test methods to detect and characterise endocrine disrupting chemicals are urgently needed for the purpose of environmental risk assessment. Although endocrine disruption in invertebrates has not been studied as extensive as in vertebrates, in particular in fish, numerous reports...

  5. Towards the review of the European Union Water Framework Directive: Recommendations for more efficient assessment and management of chemical contamination in European surface water resources.

    Science.gov (United States)

    Brack, Werner; Dulio, Valeria; Ågerstrand, Marlene; Allan, Ian; Altenburger, Rolf; Brinkmann, Markus; Bunke, Dirk; Burgess, Robert M; Cousins, Ian; Escher, Beate I; Hernández, Félix J; Hewitt, L Mark; Hilscherová, Klára; Hollender, Juliane; Hollert, Henner; Kase, Robert; Klauer, Bernd; Lindim, Claudia; Herráez, David López; Miège, Cécil; Munthe, John; O'Toole, Simon; Posthuma, Leo; Rüdel, Heinz; Schäfer, Ralf B; Sengl, Manfred; Smedes, Foppe; van de Meent, Dik; van den Brink, Paul J; van Gils, Jos; van Wezel, Annemarie P; Vethaak, A Dick; Vermeirssen, Etienne; von der Ohe, Peter C; Vrana, Branislav

    2017-01-15

    Water is a vital resource for natural ecosystems and human life, and assuring a high quality of water and protecting it from chemical contamination is a major societal goal in the European Union. The Water Framework Directive (WFD) and its daughter directives are the major body of legislation for the protection and sustainable use of European freshwater resources. The practical implementation of the WFD with regard to chemical pollution has faced some challenges. In support of the upcoming WFD review in 2019 the research project SOLUTIONS and the European monitoring network NORMAN has analyzed these challenges, evaluated the state-of-the-art of the science and suggested possible solutions. We give 10 recommendations to improve monitoring and to strengthen comprehensive prioritization, to foster consistent assessment and to support solution-oriented management of surface waters. The integration of effect-based tools, the application of passive sampling for bioaccumulative chemicals and an integrated strategy for prioritization of contaminants, accounting for knowledge gaps, are seen as important approaches to advance monitoring. Including all relevant chemical contaminants in more holistic "chemical status" assessment, using effect-based trigger values to address priority mixtures of chemicals, to better consider historical burdens accumulated in sediments and to use models to fill data gaps are recommended for a consistent assessment of contamination. Solution-oriented management should apply a tiered approach in investigative monitoring to identify toxicity drivers, strengthen consistent legislative frameworks and apply solutions-oriented approaches that explore risk reduction scenarios before and along with risk assessment.

  6. Evidence from pharmacology and pathophysiology suggests that chemicals with dissimilar mechanisms of action could be of bigger concern in the toxicological risk assessment of chemical mixtures than chemicals with a similar mechanism of action

    DEFF Research Database (Denmark)

    Hadrup, Niels

    2014-01-01

    mechanisms of action, similar modes of action or with common target organs. In the European Union, efforts are currently being made to subgroup chemicals according to this need. However, it remains to be determined whether this is the best strategy to obtain data for risk assessment. In conditions...... such as cancer or HIV, it is generally recognised that pharmacological combination therapy targeting different mechanisms of action is more effective than a strategy where only one mechanism is targeted. Moreover, in diseases such as acute myocardial infarction and congestive heart failure, several organ systems...

  7. Prioritising chemicals used in personal care products in China for environmental risk assessment: application of the RAIDAR model.

    Science.gov (United States)

    Gouin, Todd; van Egmond, Roger; Price, Oliver R; Hodges, Juliet E N

    2012-06-01

    China represents a significant market for the sale of personal care products (PCPs). Given the continuous emission of hundreds of chemicals used in PCPs to waste water and the aquatic environment after regular use, methods for prioritising the environmental risk assessment for China are needed. In an effort to assess the prioritisation of chemicals used in PCPs in China, we have identified the chemical ingredients used in 2500 PCPs released to the Chinese market in 2009, and estimated the annual emission of these chemicals. The physical-chemical property data for these substances have been estimated and used as model inputs in the RAIDAR model. In general, the RAIDAR model provides an overall assessment of the multimedia fate of chemicals, and provides a holistic approach for prioritising chemical ingredients. The prioritisation exercise conducted in this study is shown to be strongly influenced by loss processes, such as the removal efficiencies of WWT plants and biotransformation.

  8. Chemical analysis of World Trade Center fine particulate matter for use in toxicologic assessment.

    Science.gov (United States)

    McGee, John K; Chen, Lung Chi; Cohen, Mitchell D; Chee, Glen R; Prophete, Colette M; Haykal-Coates, Najwa; Wasson, Shirley J; Conner, Teri L; Costa, Daniel L; Gavett, Stephen H

    2003-06-01

    The catastrophic destruction of the World Trade Center (WTC) on 11 September 2001 caused the release of high levels of airborne pollutants into the local environment. To assess the toxicity of fine particulate matter [particulate matter with a mass median aerodynamic diameter fraction was isolated on filters. Here we report the chemical and physical properties of PM2.5 derived from these samples and compare them with PM2.5 fractions of three reference materials that range in toxicity from relatively inert to acutely toxic (Mt. St. Helens PM; Washington, DC, ambient air PM; and residual oil fly ash). X-ray diffraction of very coarse sieved WTC PM (fraction. Analysis of WTC PM2.5 using X-ray fluorescence, neutron activation analysis, and inductively coupled plasma spectrometry showed high levels of calcium (range, 22-33%) and sulfur (37-43% as sulfate) and much lower levels of transition metals and other elements. Aqueous extracts of WTC PM2.5 were basic (pH range, 8.9-10.0) and had no evidence of significant bacterial contamination. Levels of carbon were relatively low, suggesting that combustion-derived particles did not form a significant fraction of these samples recovered in the immediate aftermath of the destruction of the towers. Because gypsum and calcite are known to cause irritation of the mucus membranes of the eyes and respiratory tract, inhalation of high doses of WTC PM2.5 could potentially cause toxic respiratory effects.

  9. Chemical assessment and antioxidant capacity of pepper (Capsicum annuum L.) seeds.

    Science.gov (United States)

    Silva, Luís R; Azevedo, Jessica; Pereira, Maria J; Valentão, Patrícia; Andrade, Paula B

    2013-03-01

    Capsicum annuum L. is reported to be the most widely cultivated species. Recently, waste of vegetable processing, like seeds, has been the subject of many studies as an attempt to find new, alternative and cheap resources of bioactive compounds with application in several industries. Despite their chemical, biological and ecological importance, C. annuum seeds are still poorly studied. To improve the knowledge on the metabolic profile of this matrix, a targeted metabolite analysis was performed in "sweet Italian" and "Reus long pairal" pepper seeds. Sterols, triterpenes, organic acids, fatty acids and volatile compounds were determined by different chromatographic methods. The antioxidant activity was assessed against DPPH(·), superoxide and nitric oxide radicals. A concentration-dependent activity was noticed against all radicals. Acetylcholinesterase inhibitory capacity was also evaluated, but no effect was found. Data provide evidence of great similarities between "sweet Italian" and "Reus long pairal" pepper seeds. The present study indicates that C. annuum seeds are a potential source of valuable bioactive compounds that could be used in food industry.

  10. Water effect on peroxy radical measurement by chemical amplification: Experimental determination and chemical mechanism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The water effect on peroxy radical measurement by chemical amplification was determined experimentally for HO2 and HO2+OH, respectively at room temperature (298±2) K and atmospheric pressure (1×105 Pa). No significant difference in water effect was observed with the type of radicals. A theoretical study of the reaction of HO2·H2O adduct with NO was performed using density functional theory at CCSD(T)/6-311 G(2d, 2p)//B3LYP/6-311 G(2d, 2p) level of theory. It was found that the primary reaction channel for the reaction is HO2·H2O+NO→HNO3+H2O (R4a). On the basis of the theoretical study, the rate constant for (R4a) was calculated using Polyrate Version 8.02 program. The fitted Arrenhnius equation for (R4a) is k = 5.49×107 T 1.03exp(?14798/T) between 200 and 2000 K. A chemical model incorporated with (R4a) was used to simulate the water effect. The water effect curve obtained by the model is in accordance with that of the experiment, suggesting that the water effect is probably caused mainly by (R4a).

  11. Water effect on peroxy radical measurement by chemical amplification: Experimental determination and chemical mechanism

    Institute of Scientific and Technical Information of China (English)

    QI Bin; LIU Lu; CHAO YuTao; WANG ZhuQing; YANG HongYan

    2008-01-01

    The water effect on peroxy radical measurement by chemical amplification was determined experi-mentally for HO2 and HO2+OH, respectively at room temperature (298+9) K and atmospheric pressure (1×105 Pa). No significant difference in water effect was observed with the type of radicals. A theoretical study of the reaction of HO2. H2O adduct with NO was performed using density functional theory at CCSD(T)/6-311 G(2d, 2p)//B3LYPI6-311 G(2d, 2p) level of theory. It was found that the primary reaction channel for the reaction is HO2. H2O+NO→HNO3+H2O (R4a). On the basis of the theoretical study, the rate constant for (R4a) was calculated using Polyrate Version 8.02 program. The fitted Arrenhnius equation for (R4a) is k=5.49×107 T1.03exp(-14798/T) between 200 and 2000 K. A chemical model in-corporated with (R4a) was used to simulate the water effect. The water effect curve obtained by the model is in accordance with that of the experiment, suggesting that the water effect is probably caused mainly by (R4a).

  12. Endocrine disrupting chemicals – probability of adverse environmental effect

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2015-03-01

    Full Text Available The paper presents some information about current state of knowledge of the risk due to exposure to endocrine disrupting chemicals (EDCs. Endocrine disruptors are defined as chemicals substances with either agonist or antagonist endocrine effects in human and wildlife. Exposure to EDCs in animals models correlate positively with an increased incidence of malformations of genital tract, on neoplasmas, obesity, alternations on male and female reproduction and changes in neuroendocrinology and behavior. Results from animal models, human clinical observations and epidemiological studies converge to implicate EDCs as a significant risk to public health.

  13. QCD Effective action at high temperature and small chemical potential

    CERN Document Server

    Villavicencio, C

    2007-01-01

    We present a construction of an effective Yang-Mills action for QCD, from the expansion of the fermionic determinant in terms of powers of the chemical potential at high temperature, for the case of massless quarks. We analyze this expansion in the perturbative region and find that it gives extra spurious information. We propose for the non-perturbative sector a simplified effective action which, in principle, contains only the relevant information.

  14. Global Change Effects on Plant Chemical Defenses against Insect Herbivores

    Institute of Scientific and Technical Information of China (English)

    M. Gabriela Bidart-Bouzat; Adebobola Imeh-Nathaniel

    2008-01-01

    This review focuses on individual effects of major global change factors, such as elevated CO2, Oa, UV light and temperature,on plant secondary chemistry. These secondary metabolites are well-known for their role in plant defense against insect herbivory. Global change effects on secondary chemicals appear to be plant species-specific and dependent on the chemical type. Even though plant chemical responses induced by these factors are highly variable, there seems to be some specificity in the response to different environmental stressors. For example, even though the production of phenolic compounds is enhanced by both elevated CO2 and UV light levels, the latter appears to primarily increase the concentrations of fiavonoids. Likewise, specific phenolic metabolites seem to be induced by O3 but not by other factors, and an increase in volatile organic compounds has been particularly detected under elevated temperature. More information is needed regarding how global change factors influence inducibility of plant chemical defenses as well as how their indirect and direct effects impact insect performance and behavior, herbivory rates and pathogen attack. This knowledge is crucial to better understand how plants and their associated natural enemies will be affected in future changing environments.

  15. Conceptualising the effectiveness of impact assessment processes

    OpenAIRE

    Chanchitpricha, Chaunjit; Bond, Alan

    2013-01-01

    This paper aims at conceptualising the effectiveness of impact assessment processes through the development of a literature-based framework of criteria to measure impact assessment effectiveness. Four categories of effectiveness were established: procedural, substantive, transactive and normative, each containing a number of criteria; no studies have previously brought together all four of these categories into such a comprehensive, criteria-based framework and undertaken systemat...

  16. The Developing Brain: A Largely Overlooked Health Endpoint in Risk Assessments for Synthetic Chemical Substances

    Science.gov (United States)

    McElgunn, Barbara

    2010-01-01

    A large body of experimental animal research on the neurotoxic effects of certain environmental chemicals provides evidence of a cascade of neurobehavioural effects including learning deficits, hyperactivity, anxiety, depression, lack of motivation, increased aggressiveness, altered maternal care and bonding, and an over-reaction to small…

  17. Sociocultural effects in neuropsychological assessment.

    Science.gov (United States)

    Ostrosky-Solis, F; Canseco, E; Quintanar, L; Navarro, E; Meneses, S; Ardila, A

    1985-07-01

    The group selected for this evaluation consisted of 109 normal people with an average age of 25, coming from two different sociocultural levels (high and low) of Mexico City. All were completely evaluated by Luria's battery for neuropsychological assessment, adapted by Ardila, Ostrosky, and Canseco, 1981. This group of tests measures nine different areas: Motor Functions, Somatosensory Knowledge, Auditory Knowledge, Visuospatial Knowledge, Cognitive Processes, Language, Reading, Writing and Basic Calculations. For all of these, the higher performance standards were achieved by the subjects from the high sociocultural level. A significant interaction between sociocultural level and sex was observed. The differences between sexes appear only in subjects from the low sociocultural level. Factor analysis of the battery revealed that the most sensitive items to sociocultural level were those related on one hand, to the handling of complex structural and conceptual aspects of language and on the other hand, to the organization of motor sequences and in general motor programming. Research related to the differences found is reviewed and implications for clinical assessment are discussed.

  18. Biological effects of mechanically and chemically dispersed oil on the Icelandic scallop (Chlamys islandica).

    Science.gov (United States)

    Frantzen, Marianne; Regoli, Francesco; Ambrose, William G; Nahrgang, Jasmine; Geraudie, Perrine; Benedetti, Maura; Locke, William L; Camus, Lionel

    2016-05-01

    This study aimed to simulate conditions in which dispersant (Dasic NS) might be used to combat an oil spill in coastal sub-Arctic water of limited depth and water exchange in order to produce input data for Net Environmental Benefit Analysis (NEBA) of Arctic and sub-Arctic coastal areas. Concentration dependent differences in acute responses and long-term effects of a 48h acute exposure to dispersed oil, with and without the application of a chemical dispersant, were assessed on the Arctic filter feeding bivalve Chlamys islandica. Icelandic scallops were exposed for 48h to a range of spiked concentrations of mechanically and chemically dispersed oil. Short-term effects were assessed in terms of lysosomal membrane stability, superoxide dismutase, catalase, gluthatione S-transferases, glutathione peroxidases, glutathione reductase, glutathione, total oxyradical scavenging capacity, lipid peroxidation and peroxisomal proliferation. Post-exposure survival, growth and reproductive investment were followed for 2 months to evaluate any long-term consequence. Generally, similar effects were observed in scallops exposed to mechanically and chemically dispersed oil. Limited short-term effects were observed after 48h, suggesting that a different timing would be required for measuring the possible onset of such effects. There was a concentration dependent increase in cumulative post-exposure mortality, but long-term effects on gonadosomatic index, somatic growth/condition factor did not differ among treatments.

  19. A review of human biomonitoring data used in regulatory risk assessment under Canada's Chemicals Management Program.

    Science.gov (United States)

    Zidek, Angelika; Macey, Kristin; MacKinnon, Leona; Patel, Mikin; Poddalgoda, Devika; Zhang, Yi

    2016-10-21

    As a part of the Chemicals Management Plan launched in 2006, the Government of Canada is assessing and managing, where appropriate, the potential health and ecological risks associated with approximately 4300 substances under the Canadian Environmental Protection Act (1999). Since that time, nearly 3000 substances have been assessed, with human biomonitoring (HBM) data playing an increasingly important role for some substances. Case studies are presented, including both inorganic and organic substances (i.e., selenium, triclosan, phthalates), which highlight the impact and overall role HBM has had in regulatory decision making in Canada for these three substances as well as criteria used in the application of HBM data in human health risk assessment. An overview of its limitations in terms of how and when HBM data can be applied, when assessing human health in a regulatory setting, is discussed as well as the role HBM data can play in priority setting.

  20. Chemical conditions in present and future ecosystems in Forsmark - implications for selected radionuclides in the safety assessment SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Troejbom, Mats (Mats Troejbom Konsult AB (Sweden)); Grolander, Sara (Facilia AB (Sweden))

    2010-12-15

    This report is a background report for the biosphere analysis of the SR-Site Safety Assessment. This work aims to describe the future development of the chemical conditions at Forsmark, based on the present chemical conditions at landscape level taking landscape development and climate cases into consideration. The results presented contribute to the overall understanding of the present and future chemistry in the Forsmark area, and specifically, to the understanding of the behaviour of some selected radionuclides in the surface system. The future development of the chemistry at the site is qualitatively discussed with focus on the interglacial within the next 10,000 years. The effects on the chemical environment of future climate cases as Global Warming and cold permafrost climates are also briefly discussed. The work is presented in two independent parts describing background radionuclide activities in the Forsmark area and the distribution and behaviour of a large number of stable elements in the landscape. In a concluding section, implications of the future chemical environment of a selection of radionuclides important in the Safety Assessment are discussed based on the knowledge of stable elements. The broad range of elements studied show that there are general and expected patterns for the distribution and behaviour in the landscape of different groups of elements. Mass balances reveal major sources and sinks, pool estimations show where elements are accumulated in the landscape and estimations of time-scales give indications of the potential future development. This general knowledge is transferred to radionuclides not measured in order to estimate their behaviour and distribution in the landscape. It could be concluded that the future development of the chemical environment in the Forsmark area might affect element specific parameters used in de radionuclide model in different directions depending on element. The alternative climate cases, Global Warming

  1. [Predictive models for the assessment of occupational exposure to chemicals: a new challenge for employers].

    Science.gov (United States)

    Gromiec, Jan Piotr; Kupczewska-Dobecka, Małgorzata; Jankowska, Agnieszka; Czerczak, Sławomir

    2013-01-01

    Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation exposure and related risk to check the compliance with Occupational Exposure Limits (OELs), as well as the compliance with REACH obligations. Based on the literature data HSE COSHH Essentials, EASE, ECETOC TRA, Stoffenmanager, and EMKG-Expo-Tool were evaluated. The data on validation of predictive models were also examined. It seems that predictive models may be used as a useful method for Tier 1 assessment of occupational exposure by inhalation. Since the levels of exposure are frequently overestimated, they should be considered as "rational worst cases" for selection of proper control measures. Bearing in mind that the number of available exposure scenarios and PROC categories is limited, further validation by field surveys is highly recommended. Predictive models may serve as a good tool for preliminary risk assessment and selection of the most appropriate risk control measures in Polish small and medium size enterprises (SMEs) providing that they are available in the Polish language. This also requires an extensive training of their future users.

  2. Predictive models for the assessment of occupational exposure to chemicals: A new challenge for employers

    Directory of Open Access Journals (Sweden)

    Jan Piotr Gromiec

    2013-10-01

    Full Text Available Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation exposure and related risk to check the compliance with Occupational Exposure Limits (OELs, as well as the compliance with REACH obligations. Based on the literature data HSE COSHH Essentials, EASE, ECETOC TRA, Stoffenmanager, and EMKG-Expo-Tool were evaluated. The data on validation of predictive models were also examined. It seems that predictive models may be used as a useful method for Tier 1 assessment of occupational exposure by inhalation. Since the levels of exposure are frequently overestimated, they should be considered as "rational worst cases" for selection of proper control measures. Bearing in mind that the number of available exposure scenarios and PROC categories is limited, further validation by field surveys is highly recommended. Predictive models may serve as a good tool for preliminary risk assessment and selection of the most appropriate risk control measures in Polish small and medium size enterprises (SMEs providing that they are available in the Polish language. This also requires an extensive training of their future users. Med Pr 2013;64(5:699–716

  3. Effective conductivity of chemically deposited ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Robles, M. [Universidad Autonoma del Estado de Morelos (UAEM), Cuernavaca (Mexico). Fac. de Ciencias; Tagueena-Martinez, J. [IIM-UNAM, Temixco, Morelos (Mexico). Lab. de Energia Solar; Del Rio, J.A. [IIM-UNAM, Temixco, Morelos (Mexico). Lab. de Energia Solar

    1997-01-30

    Chemically deposited thin films have multiple applications. However, as a result of their complex structure, their physical properties are very difficult to predict. In this paper, we use an effective medium approach to model these heterogeneous systems. We extend Thorpe`s formula for the effective electrical conductivity of elliptical holes randomly distributed in a matrix to a system composed of conducting ellipses in a conducting matrix. This extension is used to calculate the effective electrical conductivity of polycrystalline chemically deposited ZnO thin films. We compare experimental results obtained by two different deposition methods: spray pyrolysis and successive ion layer adsorption and reaction (SILAR) reported here. We select the elliptical geometric parameters from microstructural data. Good agreement between the experimental measurements and our calculation is obtained. In addition, we present a new proof of the reciprocity theorem used to derive the theoretical relation. (orig.)

  4. Environmental Chemical Assessment in Clinical Practice: Unveiling the Elephant in the Room.

    Science.gov (United States)

    Bijlsma, Nicole; Cohen, Marc M

    2016-02-02

    A growing body of evidence suggests chemicals present in air, water, soil, food, building materials and household products are toxicants that contribute to the many chronic diseases typically seen in routine medical practice. Yet, despite calls from numerous organisations to provide clinicians with more training and awareness in environmental health, there are multiple barriers to the clinical assessment of toxic environmental exposures. Recent developments in the fields of systems biology, innovative breakthroughs in biomedical research encompassing the "-omics" fields, and advances in mobile sensing, peer-to-peer networks and big data, provide tools that future clinicians can use to assess environmental chemical exposures in their patients. There is also a need for concerted action at all levels, including actions by individual patients, clinicians, medical educators, regulators, government and non-government organisations, corporations and the wider civil society, to understand the "exposome" and minimise the extent of toxic exposures on current and future generations. Clinical environmental chemical risk assessment may provide a bridge between multiple disciplines that uses new technologies to herald in a new era in personalised medicine that unites clinicians, patients and civil society in the quest to understand and master the links between the environment and human health.

  5. Environmental Chemical Assessment in Clinical Practice: Unveiling the Elephant in the Room

    Directory of Open Access Journals (Sweden)

    Nicole Bijlsma

    2016-02-01

    Full Text Available A growing body of evidence suggests chemicals present in air, water, soil, food, building materials and household products are toxicants that contribute to the many chronic diseases typically seen in routine medical practice. Yet, despite calls from numerous organisations to provide clinicians with more training and awareness in environmental health, there are multiple barriers to the clinical assessment of toxic environmental exposures. Recent developments in the fields of systems biology, innovative breakthroughs in biomedical research encompassing the “-omics” fields, and advances in mobile sensing, peer-to-peer networks and big data, provide tools that future clinicians can use to assess environmental chemical exposures in their patients. There is also a need for concerted action at all levels, including actions by individual patients, clinicians, medical educators, regulators, government and non-government organisations, corporations and the wider civil society, to understand the “exposome” and minimise the extent of toxic exposures on current and future generations. Clinical environmental chemical risk assessment may provide a bridge between multiple disciplines that uses new technologies to herald in a new era in personalised medicine that unites clinicians, patients and civil society in the quest to understand and master the links between the environment and human health.

  6. In vitro methods for hazard assessment of industrial chemicals – opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Chin Lin eWong

    2015-05-01

    Full Text Available Allergic contact dermatitis (ACD is a delayed-type hypersensitivity immune reaction mediated by T-lymphocytes as a result of repeated exposure of an allergen primarily on skin. ACD accounts for up to 95% of occupational skin diseases (OSDs, with epoxy resins implicated as one of the most common causes of ACD. Efficient high-throughput in vitro screening for accurate identification of compounds and materials that may pose hazardous risks in the workplace is crucial. At present, the murine local lymph node assay (LLNA is the ‘method of choice’ for predicting the sensitizing potency of contact allergens. As the 3Rs principles of reduction, refinement and replacement in animal testing has gained political and economic momentum, several in vitro screening methods have been developed for identifying potential contact allergens. To date, these latter methods have been utilized primarily to assess the skin sensitizing potential of the chemical components of cosmetic products with scant research attention as to the applicability of these methods to industrial chemicals, particularly epoxy resins. Herein we review the currently utilized in vitro methods and identify the knowledge gaps with regard to assessing the generalizability of in vitro screening methods for assessing the skin sensitizing potential of industrial chemicals.

  7. Biological effects of low level exposures to chemicals and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Calabrese, E.J. (ed.)

    1992-01-01

    In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biological effects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on Effects of low-dose radiation on the immune response' was presented as well as Cellular adaptation as an important response during chemical carcinogenesis'. The final presentation was devoted to biostatistical considerations when designing studies that address issues associated with the biological responses to low doses of chemicals and radiation, as well as issues in interpretation of the findings from such studies.

  8. Effects of irrigation efficiency on chemical transport processes

    Institute of Scientific and Technical Information of China (English)

    WANG Kang; ZHANG RenDuo; SHENG Feng

    2009-01-01

    Irrigation practices greatly affect sustainable agriculture development.In this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils, which had significant impact on the environment.Field dye staining experiments were conducted at different soils with various irrigation amount.Image analysis was conducted to study the heterogeneous flow patterns and their relationships with the irrigation efficiency.Irrigation efficiency and its environmental effects were evaluated using various indictors, including application efficiency, deep percolation ratio, storage effi-ciency, and uniformity.Under the same irrigation condition, soil chemical distributions were more het-erogeneous than soil water distributions.The distributions were mainly affected by soil texture, initial soil water content, and irrigation amount.Storage efficiency, irrigation uniformity, and deep percolation ratio increased with irrigation amount.Since the chemical distribution uniformity was lower than the water uniformity, the amount of chemical leaching increased sharply with decrease of irrigation uni-formity, which resulted in high environmental risks of groundwater pollution.

  9. Combination of chemical analyses and animal feeding trials as reliable procedures to assess the safety of heat processed soybean seeds.

    Science.gov (United States)

    Vasconcelos, Ilka M; Brasil, Isabel Cristiane F; Oliveira, José Tadeu A; Campello, Cláudio C; Maia, Fernanda Maria M; Campello, Maria Verônica M; Farias, Davi F; Carvalho, Ana Fontenele U

    2009-06-10

    This study assessed whether chemical analyses are sufficient to guarantee the safety of heat processing of soybeans (SB) for human/animal consumption. The effects of extrusion and dry-toasting were analyzed upon seed composition and performance of broiler chicks. None of these induced appreciable changes in protein content and amino acid composition. Conversely, toasting reduced all antinutritional proteins by over 85%. Despite that, the animals fed on toasted SB demonstrated a low performance (feed efficiency 57.8 g/100 g). Extrusion gave place to higher contents of antinutrients, particularly of trypsin inhibitors (27.53 g/kg flour), but animal performance was significantly (p trials, extrusion appears to be the safest method. In conclusion, in order to evaluate the reliability of any processing method intended to improve nutritional value, the combination of chemical and animal studies is necessary.

  10. The effect of the indoor environment on the fate of organic chemicals in the urban landscape.

    Science.gov (United States)

    Cousins, Anna Palm

    2012-11-01

    To assess the effect of the indoor environment on the urban fate of organic chemicals, an 8-compartment indoor-inclusive steady state multimedia chemical fate model was developed. The model includes typical urban compartments (air, soil, water, sediment, and urban film) and a novel module representing a generic indoor environment. The model was parameterized to the municipality of Stockholm, Sweden and applied to four organic chemicals with different physical-chemical characteristics and use patterns: formaldehyde, 2,4,6-tribromophenol, di-ethylhexylphthalate and decabromodiphenyl ether. The results show that emissions to indoor air may increase the steady state mass and residence time in the urban environment by a factor of 1.1 to 22 for the four chemicals, compared to if emissions are assigned to outdoor air. This is due to the nested nature of the indoor environment, which creates a physical barrier that prevents chemicals from leaving the urban system with outflowing air. For DEHP and BDE 209, the additional partitioning to indoor surfaces results in a greater importance of the indoor removal pathways from surfaces. The outdoor environmental concentrations of these chemicals are predicted to be lower if emitted to indoor air than if emitted to outdoor air because of the additional indoor removal pathways of dust and indoor film, leading to loss of chemical from the system. For formaldehyde and 2,4,6-TBP outdoor environmental concentrations are not affected by whether the release occurs indoors or outdoors because of the limited partitioning to indoor surfaces. A sensitivity analysis revealed that there appears to be a relationship between logK(OA) and the impact of the ventilation rate on the urban fate of organic chemicals.

  11. Cigarette butt decomposition and associated chemical changes assessed by 13C CPMAS NMR.

    Science.gov (United States)

    Bonanomi, Giuliano; Incerti, Guido; Cesarano, Gaspare; Gaglione, Salvatore A; Lanzotti, Virginia

    2015-01-01

    Cigarette butts (CBs) are the most common type of litter on earth, with an estimated 4.5 trillion discarded annually. Apart from being unsightly, CBs pose a serious threat to living organisms and ecosystem health when discarded in the environment because they are toxic to microbes, insects, fish and mammals. In spite of the CB toxic hazard, no studies have addressed the effects of environmental conditions on CB decomposition rate. In this study we investigate the interactive effects of substrate fertility and N transfer dynamics on CB decomposition rate and carbon quality changes. We carried out an experiment using smoked CBs and wood sticks, used as a slow decomposing standard organic substrate, incubated in both laboratory and field conditions for two years. CB carbon quality changes during decomposition was assessed by 13C CPMAS NMR. Our experiment confirmed the low degradation rate of CBs which, on average, lost only 37.8% of their initial mass after two years of decomposition. Although a net N transfer occurred from soil to CBs, contrary to our hypothesis, mass loss in the medium-term (two years) was unaffected by N availability in the surrounding substrate. The opposite held for wood sticks, in agreement with the model that N-rich substrates promote the decomposition of other N-poor natural organic materials with a high C/N ratio. As regards CB chemical quality, after two years of decomposition 13C NMR spectroscopy highlighted very small changes in C quality that are likely to reflect a limited microbial attack.

  12. Cigarette butt decomposition and associated chemical changes assessed by 13C CPMAS NMR.

    Directory of Open Access Journals (Sweden)

    Giuliano Bonanomi

    Full Text Available Cigarette butts (CBs are the most common type of litter on earth, with an estimated 4.5 trillion discarded annually. Apart from being unsightly, CBs pose a serious threat to living organisms and ecosystem health when discarded in the environment because they are toxic to microbes, insects, fish and mammals. In spite of the CB toxic hazard, no studies have addressed the effects of environmental conditions on CB decomposition rate. In this study we investigate the interactive effects of substrate fertility and N transfer dynamics on CB decomposition rate and carbon quality changes. We carried out an experiment using smoked CBs and wood sticks, used as a slow decomposing standard organic substrate, incubated in both laboratory and field conditions for two years. CB carbon quality changes during decomposition was assessed by 13C CPMAS NMR. Our experiment confirmed the low degradation rate of CBs which, on average, lost only 37.8% of their initial mass after two years of decomposition. Although a net N transfer occurred from soil to CBs, contrary to our hypothesis, mass loss in the medium-term (two years was unaffected by N availability in the surrounding substrate. The opposite held for wood sticks, in agreement with the model that N-rich substrates promote the decomposition of other N-poor natural organic materials with a high C/N ratio. As regards CB chemical quality, after two years of decomposition 13C NMR spectroscopy highlighted very small changes in C quality that are likely to reflect a limited microbial attack.

  13. Screening of endocrine disrupting chemicals with MELN cells, an ER-transactivation assay combined with cytotoxicity assessment.

    Science.gov (United States)

    Berckmans, P; Leppens, H; Vangenechten, C; Witters, H

    2007-10-01

    There is growing concern that some chemicals can cause endocrine disrupting effects to wild animals and humans. Therefore a rapid and reliable screening assay to assess the activity of endocrine disrupting chemicals (EDCs) is required. These EDCs can act at multiple sites. Most studied mechanism is direct interaction with the hormone receptors, e.g. estrogen receptor. In this study the luciferase reporter gene assay using transgenic human MELN cells was used. Since cytotoxicity of the chemicals can decrease the luminescent signal in the transactivation assays, a cytotoxicity assay must be implemented. Mostly the neutral red (NR) assay is performed in parallel with the estrogenicity assay. To increase the reliability and cost-efficiency of the test, a method to measure estrogenicity and cytotoxicity in the same cell culture plate instead of in parallel plates was developed and evaluated. Therefore the NR-assay was compared with the CytoTox-ONE homogeneous membrane integrity assay. The latter measures LDH (lactate dehydrogenase) leakage based on a fluorometric method. For all compounds tested, the CytoTox-ONE test showed comparable curves and EC50-values to those obtained by the NR-assay. So the CytoTox-ONE kit, which seemed more sensitive than measurements of LDH-leakage based on a colorimetric method, is recommended to test cytotoxicity to MELN cells, with the advantage to use the same cells for ER-transactivation measurements. The chemicals tested in the optimised MELN assay showed estrogenic potencies comparable to those reported for several other transactivation assays.

  14. Physico-chemical and biochemical approaches to assessing the development of precancerous pathologies of the gastrointestinal tract during their modeling in mice with complex effects of stress factors of different nature

    Science.gov (United States)

    Alieva, Zamira O.; Kanevskiy, Matvej V.; Galitskaya, Anna A.; Mironova, Irina K.; Pleshakova, Ekaterina V.; Velikov, Vladimir A.; Chumakov, Daniil S.; Semyachkina-Glushkovskaya, Oxana V.; Konnova, Svetlana A.

    2016-04-01

    It was shown in the experience with 60 white mice that separate and combined effects of stress factors: noctidial lighting (800 lux), sodium nitrite (0.2% solution in water) and p-toluidine (with food) within 107 days causes a change in impedance value of erythrocytes at frequencies 1 Hz - 1MHz. Changes in the activity of intracellular aminotransferases, creatinine and urea were observed, indicating cardiotoxic and hepatotoxic effects.

  15. The effect of alkaline agents on retention of EOR chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, P.B.

    1991-07-01

    This report summarizes a literature survey on how alkaline agents reduce losses of surfactants and polymers in oil recovery by chemical injection. Data are reviewed for crude sulfonates, clean anionic surfactants, nonionic surfactants, and anionic and nonionic polymers. The role of mineral chemistry is briefly described. Specific effects of various alkaline anions are discussed. Investigations needed to improve the design of alkaline-surfactant-polymer floods are suggested. 62 refs., 28 figs., 6 tabs.

  16. Chemical and structural effects of base modifications in messenger RNA

    Science.gov (United States)

    Harcourt, Emily M.; Kietrys, Anna M.; Kool, Eric T.

    2017-01-01

    A growing number of nucleobase modifications in messenger RNA have been revealed through advances in detection and RNA sequencing. Although some of the biochemical pathways that involve modified bases have been identified, research into the world of RNA modification -- the epitranscriptome -- is still in an early phase. A variety of chemical tools are being used to characterize base modifications, and the structural effects of known base modifications on RNA pairing, thermodynamics and folding are being determined in relation to their putative biological roles.

  17. Determination of the capabilities of a detachment for neutralizing chemical attack effects in the brigade defense zone

    Directory of Open Access Journals (Sweden)

    Dejan R. Inđić

    2012-04-01

    Full Text Available This paper presents one possible way of deploying detachments for neutralizing the effects of chemical attacks in a brigade defense zone. The detachment composition is provisional and depends on the assessment of whether the enemy in the incoming combat will use weapons of mass destruction. A detachment consists of several organizational units: medical care forces, chemical reconnaissance forces, forces for the establishment of combat efficiency and chemical decontamination forces. The capabilities of the mentioned forces depend on their size, equipment, training level, extent of effects and combat conditions. The paper indicates a potential to overcome the gap in the provisions after disbanding the Army Corps.

  18. Enhancing the chemical mixture methodology in emergency preparedness and consequence assessment analysis.

    Science.gov (United States)

    Yu, Xiao-Ying; Glantz, Clifford S; Yao, Juan; He, Hua; Petrocchi, Achille J; Craig, Douglas K; Ciolek, John T; Booth, Alexander E

    2013-11-16

    Emergency preparedness personnel at U.S. Department of Energy (DOE) facilities use the chemical mixture methodology (CMM) to estimate the potential health impacts to workers and the public from the unintended airborne release of chemical mixtures. The CMM uses a Hazard Index (HI) for each chemical in a mixture to compare a chemical's concentration at a receptor location to an appropriate concentration limit for that chemical. This limit is typically based on Protection Action Criteria (PAC) values developed and published by the DOE. As a first cut, the CMM sums the HIs for all the chemicals in a mixture to conservatively estimate their combined health impact. A cumulative HI>1.0 represents a concentration exceeding the concentration limit and indicates the potential for adverse health effects. Next, Health Code Numbers (HCNs) are used to identify the target organ systems that may be impacted by exposure to each chemical in a mixture. The sum of the HIs for the maximally impacted target organ system is used to provide a refined, though still conservative, estimate of the potential for adverse health effects from exposure to the chemical mixture. This paper explores approaches to enhance the effectiveness of the CMM by using HCN weighting factors. A series of 24 case studies have been defined to evaluate both the existing CMM and three new approaches for improving the CMM. The first approach uses a set of HCN weighting factors that are applied based on the priority ranking of the HCNs for each chemical. The second approach uses weighting factors based on the priority rankings of the HCNs established for a given type of concentration limit. The third approach uses weighting factors that are based on the exposure route used to derive PAC values and a priority ranking of the HCNs (the same ranking as used in the second approach). Initial testing indicates that applying weighting factors increases the effectiveness of the CMM in general, though care must be taken to

  19. From single chemicals to mixtures--reproductive effects of levonorgestrel and ethinylestradiol on the fathead minnow.

    Science.gov (United States)

    Runnalls, Tamsin J; Beresford, Nicola; Kugathas, Subramaniam; Margiotta-Casaluci, Luigi; Scholze, Martin; Scott, Alexander P; Sumpter, John P

    2015-12-01

    The aquatic environment is polluted with thousands of chemicals. It is currently unclear which of these pose a significant threat to aquatic biota. The typical exposure scenario is now represented by a widespread blanket of contamination composed of myriads of individual pollutants-each typically present at a low concentration. The synthetic steroids, 17α-ethinylestradiol and levonorgestrel, have been widely reported to be present in the aquatic environment in the low ng to sub-ng/l range. They are widely used in contraceptive formulations, both individually and in combination. Our research employed the fathead minnow (Pimephales promelas) 21 day 'pair-breeding' assay to assess reproductive output when pairs of fish were exposed to the single chemicals at low environmentally relevant concentrations, and then to a binary mixture of them. A variety of endpoints were assessed, including egg production, which was inhibited in a concentration-dependent manner by both the individual chemicals and the mixture. Significant, sex specific effects were also seen with both chemicals, at differing levels of biological organisation. Plasma concentrations of EE2 and levonorgestrel were predicted and in the case of levonorgestrel measured, and compared with the human therapeutic plasma concentrations (Read-Across approach) to support the interpretation of the results. A novel quantitative method was developed for the data analysis, which ensured a suitable endpoint for the comparative mixture assessment. This approach compares the reproductive performance from individual pairs of fish during chemical exposure to its pre-treatment performance. The responses from the empirical mixture study were compared to predictions derived from the single substance data. We hypothesised combined responses which were best described by the concept of concentration addition, and found no clear indications against this additivity expectation. However, the effect profiles support the current

  20. [Stressful effects of chemical toxins at low concentrations].

    Science.gov (United States)

    Parfeniuk, S B; Khrenov, M O; Novoselova, T V; Glushkova, O V; Lunin, S M; Fesenko, E E; Novoselova, E G

    2010-01-01

    Effects of three chemical compounds: ammonia, diethyl ether, and acetic acid, known as common environmental contaminants in technogenic accidents, were investigated in vivo and in vitro in low concentrations. When added in cultivation media, each of the chemicals has affected peritoneal macrophages and spleen lymphocytes isolated from male NMRI mice and led to a rise in the production of several cytokines, particularly the tumor necrosis factor-alpha and interferon-gamma, as well as the expression of the inducible form of heat shock proteins (HSP72 and HSP90-alpha) and in the activation of signal cascades NF-kappaB and SAPK/JNK. The increase of the nitric oxide (NO) production in macrophages has been observed only when ammonia was added in cultivation media. Also, low concentrations of all compounds investigated led to the activation of the expression of receptor protein TLR4. When mice were exposed to airborne toxic contaminants in a hermetically sealed experimental chamber, an increase in the concentrations of cytokines, heat shock proteins, and signal proteins in immune cells was also observed in response to low concentrations of all chemicals investigated. Similarly to in vitro experiments, the NO production was augmented only in the presence of the airborne ammonia. The results indicate the environmental hazard of chemical contaminants even in rather low concentrations, which nevertheless lead to the stress response.

  1. Determination of contamination of a chemical warfare-proof operating theatre with volatile anaesthetic agents and assessment of anaesthetic gas scavenging systems.

    Science.gov (United States)

    Yoganathan, S; Johnston, I G; Parnell, C J; Houghton, I T; Restall, J

    1991-11-01

    Three types of anaesthetic waste scavenging systems (active antipollution system, Papworth Block passive system and activated charcoal absorber system) were compared with a non-scavenging control to assess their effectiveness in reducing waste halothane concentrations in a chemical warfare-proof operating theatre. All three systems were found to reduce the level of pollution significantly.

  2. Dose-response modeling : Evaluation, application, and development of procedures for benchmark dose analysis in health risk assessment of chemical substances

    OpenAIRE

    Sand, Salomon

    2005-01-01

    In this thesis, dose-response modeling and procedures for benchmark dose (BMD) analysis in health risk assessment of chemical substances have been investigated. The BMD method has been proposed as an alternative to the NOAEL (no-observedadverse- effect-level) approach in health risk assessment of non-genotoxic agents. According to the BMD concept, a dose-response model is fitted to data and the BMD is defined as the dose causing a predetermined change in response. A lowe...

  3. Environmental risk assessment of combined effects in aquatic ecotoxicology: a discussion paper.

    Science.gov (United States)

    Beyer, Jonny; Petersen, Karina; Song, You; Ruus, Anders; Grung, Merete; Bakke, Torgeir; Tollefsen, Knut Erik

    2014-05-01

    Environmental regulatory edicts within the EU, such as the regulatory framework for chemicals REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), the Water Framework Directive (WFD), and the Marine Strategy Framework Directive (MSFD) focus mainly on toxicity assessment of individual chemicals although the effect of contaminant mixtures is a matter of increasing concern. This discussion paper provides an overview of the field of combined effects in aquatic ecotoxicology and addresses some of the major challenges related to assessment of combined effects in connection with environmental risk assessment (ERA) and regulation. Potentials and obstacles related to different experimental, modelling and predictive ERA approaches are described. On-going ERA guideline and manual developments in Europe aiming to incorporate combined effects of contaminants, the use of different experimental approaches for providing combined effect data, the involvement of biomarkers to characterize Mode of Action and toxicity pathways and efforts to identify relevant risk scenarios related to combined effects are discussed.

  4. Addressing Human Variability in Next-Generation Human Health Risk Assessments of Environmental Chemicals

    Science.gov (United States)

    Bois, Frederic Y.; Chiu, Weihsueh A.; Hattis, Dale; Rusyn, Ivan; Guyton, Kathryn Z.

    2012-01-01

    Background: Characterizing variability in the extent and nature of responses to environmental exposures is a critical aspect of human health risk assessment. Objective: Our goal was to explore how next-generation human health risk assessments may better characterize variability in the context of the conceptual framework for the source-to-outcome continuum. Methods: This review was informed by a National Research Council workshop titled “Biological Factors that Underlie Individual Susceptibility to Environmental Stressors and Their Implications for Decision-Making.” We considered current experimental and in silico approaches, and emerging data streams (such as genetically defined human cells lines, genetically diverse rodent models, human omic profiling, and genome-wide association studies) that are providing new types of information and models relevant for assessing interindividual variability for application to human health risk assessments of environmental chemicals. Discussion: One challenge for characterizing variability is the wide range of sources of inherent biological variability (e.g., genetic and epigenetic variants) among individuals. A second challenge is that each particular pair of health outcomes and chemical exposures involves combinations of these sources, which may be further compounded by extrinsic factors (e.g., diet, psychosocial stressors, other exogenous chemical exposures). A third challenge is that different decision contexts present distinct needs regarding the identification—and extent of characterization—of interindividual variability in the human population. Conclusions: Despite these inherent challenges, opportunities exist to incorporate evidence from emerging data streams for addressing interindividual variability in a range of decision-making contexts. PMID:23086705

  5. Effects of CW (chemical warfare)-related chemicals on social behavior and performance. Annual report, 30 September 1984-29 September 1985

    Energy Technology Data Exchange (ETDEWEB)

    Bunnell, B.N.; Iturrian, W.B.

    1985-10-01

    This report summarizes work accomplished in the second year of a three-year project aimed at developing a battery of tests of social behavior and performance that wil be sensitive to the effects of chemical warfare-related chemicals considered for use as antidotes or prophylactics against chemical-warfare agents. Procedures for assessing social behavior in nonhuman primates are described and compared. Performance scores on three operant schedules, a test of complex problem solving, and behavior in a novel environment are presented and correlations between the social and performance variables are examined. The effects of atropines on several of the social and performance measures are reported as are data from plasma hormone assays for cortisol and prolactin.

  6. An amphibian model to test the effects of xenobiotic chemicals on development of the hematopoietic system.

    Science.gov (United States)

    Rollins-Smith, Louise A; Hopkins, B Diane; Reinert, Laura K

    2004-12-01

    A number of manmade chemicals have deleterious effects on the developing immune system. Very few assay systems are available to study the effects of xenobiotics on hematopoietic stem cells. In rodent models, assays require exposure of pregnant females and analysis of the hematopoietic potential of stem cells from the offspring. These models are less relevant to lower vertebrates such as fish or amphibians where exposure of embryos is direct. To overcome this problem, an amphibian model was developed. Diploid (2N) embryos (16-20 h of age) of the South African clawed frog, Xenopus laevis, were exposed to 10 microg/ml diazinon or 10(-6) M lead acetate for 2 h. After 2 h, the ventral blood island (VBI) was transplanted from a chemically treated or untreated control embryo to an untreated triploid (3N) host embryo. After 55 d, the contribution of the donor VBI-derived stem cells to populations in the blood, thymus, and spleen was assessed by flow cytometry. Diazinon, but not lead acetate, interfered with the ability of transplanted stem cells to contribute to hematopoiesis. Because amphibian embryos are very sensitive indicators of the toxic effects of chemicals, this VBI assay could be employed to test any toxic chemical that is suspected of having a negative effect on development of the hematopoietic system.

  7. Assessment of exposure to chemical agents and ergonomic stressors in tanneries in Kanpur, India.

    Science.gov (United States)

    Ory, F G; Rahman, F U; Katagade, V; Shukla, A; Burdorf, A

    1997-10-01

    In developing countries qualitative assessment of exposure at the workplace may be an essential tool in evaluating hazardous working conditions. This survey reports on qualitative assessment of exposure to chemicals, dust, and ergonomic stressors among 298 workers in 15 tanneries in Kanpur, India. In general, chemical exposure and dermal exposure were highest among beamhouse workers, less for workers involved in dry finishing activities, and lowest for those performing the wet finishing of hides. Dermal exposure was rated as high to very high during beamhouse activities, reflecting direct contact with wet hides and manual handling of hides in soak tanks. Relevant dust exposure was observed only during dry finishing activities. Most workers experienced severe postural load due to working in trunk flexion and rotation for more than 50% of their daily work time. In addition, manual materials handling with loads over 20 kg frequently occurred. The size of the tannery, in general a reflection of state of technology, showed no systematic influence on exposure profiles. The survey suggested that mechanization of material transfer and application of trolleys reduced the work time with trunk flexion and rotation and implied less manual lifting. The presence of local exhaust ventilation in large tanneries seemed to reduce the chemical exposure. This survey has demonstrated the importance of rapid appraisal techniques for evaluating hazardous conditions at the workplace. In developing countries this approach may facilitate occupational hygiene research and practice.

  8. Use of risk assessment to evaluate effects and plan remediation of abandoned mines

    Science.gov (United States)

    Boyle, T.P.

    2000-01-01

    A framework of risk assessment is elaborated for the evaluation of the effects of abandoned mines and mills. Steps in this process include environmental description, identification and characterization of sources, assessment of exposure, assessment of effects, risk characterization, and risk management of remediation. The development and use of ecological end-points for remediation is discussed in terms of the chemical constituents, toxicity tests and the biological community.

  9. An activated sludge modeling framework for xenobiotic trace chemicals (ASM-X): assessment of diclofenac and carbamazepine.

    Science.gov (United States)

    Plósz, Benedek Gy; Langford, Katherine H; Thomas, Kevin V

    2012-11-01

    Conventional models for predicting the fate of xenobiotic organic trace chemicals, identified, and calibrated using data obtained in batch experiments spiked with reference substances, can be limited in predicting xenobiotic removal in wastewater treatment plants (WWTPs). At stake is the level of model complexity required to adequately describe a general theory of xenobiotic removal in WWTPs. In this article, we assess the factors that influence the removal of diclofenac and carbamazepine in activated sludge, and evaluate the complexity required for the model to effectively predict their removal. The results are generalized to previously published cases. Batch experimental results, obtained under anoxic and aerobic conditions, were used to identify extensions to, and to estimate parameter values of the activated sludge modeling framework for Xenobiotic trace chemicals (ASM-X). Measurement and simulation results obtained in the batch experiments, spiked with the diclofenac and carbamazepine content of preclarified municipal wastewater shows comparably high biotransformation rates in the presence of growth substrates. Forward dynamic simulations were performed using full-scale data obtained from Bekkelaget WWTP (Oslo, Norway) to evaluate the model and to estimate the level of re-transformable xenobiotics present in the influent. The results obtained in this study demonstrate that xenobiotic loading conditions can significantly influence the removal capacity of WWTPs. We show that the trace chemical retransformation in upstream sewer pipes can introduce considerable error in assessing the removal efficiency of a WWTP, based only on parent compound concentration measurements. The combination of our data with those from the literature shows that solids retention time (SRT) can enhance the biotransformation of diclofenac, which was not the case for carbamazepine. Model approximation of the xenobiotic concentration, detected in the solid phase, suggest that between

  10. Antifoaming effect of chemical compounds in manure biogas reactors.

    Science.gov (United States)

    Kougias, P G; Tsapekos, P; Boe, K; Angelidaki, I

    2013-10-15

    A precise and efficient antifoaming control strategy in bioprocesses is a challenging task as foaming is a very complex phenomenon. Nevertheless, foam control is necessary, as foam is a major operational problem in biogas reactors. In the present study, the effect of 14 chemical compounds on foam reduction was evaluated at concentration of 0.05%, 0.1% and 0.5% v/v(sample), in raw and digested manure. Moreover, two antifoam injection methods were compared for foam reduction efficiency. Natural oils (rapeseed and sunflower oil), fatty acids (oleic, octanoic and derivative of natural fatty acids), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were more efficient in reducing foam when added directly into the liquid phase rather than added in the headspace of the reactor.

  11. Sensor-based assessment of herbicide effects

    DEFF Research Database (Denmark)

    Streibig, Jens Carl; Rasmussen, Jesper; Andújar, D.;

    2014-01-01

    Non-destructive assessment of herbicide effects may be able to support integrated weed management. To test whether effects of herbicides on canopy variables could be detected by sensors, two crops were used as models and treated with herbicides at BBCH 20 using a logarithmic sprayer. Twelve days...

  12. Prioritizing Chemicals for Risk Assessment Using Chemoinformatics: Examples from the IARC Monographs on Pesticides

    Science.gov (United States)

    Guha, Neela; Guyton, Kathryn Z.; Loomis, Dana; Barupal, Dinesh Kumar

    2016-01-01

    Background: Identifying cancer hazards is the first step towards cancer prevention. The International Agency for Research on Cancer (IARC) Monographs Programme, which has evaluated nearly 1,000 agents for their carcinogenic potential since 1971, typically selects agents for hazard identification on the basis of public nominations, expert advice, published data on carcinogenicity, and public health importance. Objectives: Here, we present a novel and complementary strategy for identifying agents for hazard evaluation using chemoinformatics, database integration, and automated text mining. Discussion: To inform selection among a broad range of pesticides nominated for evaluation, we identified and screened nearly 6,000 relevant chemical structures, after which we systematically compiled information on 980 pesticides, creating network maps that allowed cluster visualization by chemical similarity, pesticide class, and publicly available information concerning cancer epidemiology, cancer bioassays, and carcinogenic mechanisms. For the IARC Monograph meetings that took place in March and June 2015, this approach supported high-priority evaluation of glyphosate, malathion, parathion, tetrachlorvinphos, diazinon, p,p′-dichlorodiphenyltrichloroethane (DDT), lindane, and 2,4-dichlorophenoxyacetic acid (2,4-D). Conclusions: This systematic approach, accounting for chemical similarity and overlaying multiple data sources, can be used by risk assessors as well as by researchers to systematize, inform, and increase efficiency in selecting and prioritizing agents for hazard identification, risk assessment, regulation, or further investigation. This approach could be extended to an array of outcomes and agents, including occupational carcinogens, drugs, and foods. Citation: Guha N, Guyton KZ, Loomis D, Barupal DK. 2016. Prioritizing chemicals for risk assessment using chemoinformatics: examples from the IARC Monographs on Pesticides. Environ Health Perspect 124:1823–1829;

  13. Automated high-throughput assessment of prostate biopsy tissue using infrared spectroscopic chemical imaging

    Science.gov (United States)

    Bassan, Paul; Sachdeva, Ashwin; Shanks, Jonathan H.; Brown, Mick D.; Clarke, Noel W.; Gardner, Peter

    2014-03-01

    Fourier transform infrared (FT-IR) chemical imaging has been demonstrated as a promising technique to complement histopathological assessment of biomedical tissue samples. Current histopathology practice involves preparing thin tissue sections and staining them using hematoxylin and eosin (H&E) after which a histopathologist manually assess the tissue architecture under a visible microscope. Studies have shown that there is disagreement between operators viewing the same tissue suggesting that a complementary technique for verification could improve the robustness of the evaluation, and improve patient care. FT-IR chemical imaging allows the spatial distribution of chemistry to be rapidly imaged at a high (diffraction-limited) spatial resolution where each pixel represents an area of 5.5 × 5.5 μm2 and contains a full infrared spectrum providing a chemical fingerprint which studies have shown contains the diagnostic potential to discriminate between different cell-types, and even the benign or malignant state of prostatic epithelial cells. We report a label-free (i.e. no chemical de-waxing, or staining) method of imaging large pieces of prostate tissue (typically 1 cm × 2 cm) in tens of minutes (at a rate of 0.704 × 0.704 mm2 every 14.5 s) yielding images containing millions of spectra. Due to refractive index matching between sample and surrounding paraffin, minimal signal processing is required to recover spectra with their natural profile as opposed to harsh baseline correction methods, paving the way for future quantitative analysis of biochemical signatures. The quality of the spectral information is demonstrated by building and testing an automated cell-type classifier based upon spectral features.

  14. Default values for assessment of potential dermal exposure of the hands to industrial chemicals in the scope of regulatory risk assessments

    NARCIS (Netherlands)

    Marquart, H.; Warren, N.D.; Laitinen, J.; Hemmen, J.J. van

    2006-01-01

    Dermal exposure needs to be addressed in regulatory risk assessment of chemicals. The models used so far are based on very limited data. The EU project RISKOFDERM has gathered a large number of new measurements on dermal exposure to industrial chemicals in various work situations, together with info

  15. Probabilistic Health Risk Assessment of Chemical Mixtures: Importance of Travel Times and Connectivity

    Science.gov (United States)

    Henri, Christopher V.; Fernàndez-Garcia, Daniel; de Barros, Felipe P. J.

    2014-05-01

    Subsurface contamination cases giving rise to groundwater pollutions are extensively found in all industrialized countries. Under this pressure, risk assessment methods play an important role in population protection by (1) quantifying the potential impact on human health of an aquifer contamination and (2) helping and driving decisions of groundwater-resource managers. Many reactive components such as chlorinated solvents or nitrates potentially experience attenuation processes under common geochemical conditions. This represents an attractive and extensively used remediation solution but leads often to the production of by-products before to reach a harmless chemical form. This renders mixtures of contaminants a common issue for groundwater resources managers. In this case, the threat posed by these contaminants to human health at a given sensitive location greatly depends on the competition between reactive and advective-dispersive characteristic times. However, hydraulic properties of the aquifer are known to be spatially variable, which can lead to the formation of preferential flow channels and fast contamination pathways. Therefore, the uncertainty on the spatial distribution of the aquifer properties controlling the plume travel time may then play a particular role in the human health risk assessment of chemical mixtures. We investigate here the risk related to a multispecies system in response to different degrees of heterogeneity of the hydraulic conductivity (K or Y =ln(K)). This work focuses on a Perchloroethylene (PCE) contamination problem followed by the sequential first-order production/biodegradation of its daughter species Trichloroethylene (TCE), Dichloroethylene (DCE) and Vinyl Chlorine (VC). For this specific case, VC is known to be a highly toxic contaminant. By performing numerical experiments, we evaluate transport through three-dimensional mildly (σY 2=1.0) and highly (σY 2=4.0) heterogeneous aquifers. Uncertainty on the hydraulic

  16. Anaerobic sediment potential acidification and metal release risk assessment by chemical characterization and batch resuspension experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nanno, M.P. di [Univ. de San Martin, Buenos Aires (Argentina). Escuela de Ciencia y Technologia; Curutchet, G. [Univ. de San Martin, Buenos Aires (Argentina). Escuela de Ciencia y Technologia; CONICET, Buenos Aires (Argentina); Ratto, S. [Univ. de Buenos Aires (Argentina). Catedra de Edafologia

    2007-06-15

    Background, Aim and Scope: Sediments act as a sink for toxic substances (heavy metals, organic pollutants) and, consequently, dredged materials often contain pollutants which are above safe limits. In polluted anaerobic sediments, the presence of sulphides and redox potential changes creates a favorable condition for sulphide oxidation to sulphate, resulting in potential toxic metal release. The oxidation reaction is catalyzed by several microorganisms. Some clean up measures, such as dredging, can initiate the process. The aim of the present work is to assess the acidification and metal release risk in the event of sediment dredging and also to compare two different acid base account techniques with the resuspension results. The oxidation mechanism by means of inoculation with an Acidithiobacillus ferrooxidans strain was also evaluated. Materials and Methods: The sediments were chemically characterized (pH; organic oxidizable carbon; acid volatile sulphides; total sulphur; moisture; Cr, Cu and Zn aqua regia contents). A metal sequential extraction procedure (Community Bureau of Reference, BCR technique) was applied to calculate the Acid Producing Potential (APP) and Acid Consuming Capacity (ACC) of the sediment samples through Fe, Ca{sup 2+} and SO{sub 4}{sup 2-} measurements. The acid base account was also performed by the Sobek methodology (Acid producing potential - AP - calculated with total sulphur and neutralization potential - NP - by titration of the remaining acid after a reaction period with the sample). Fresh sediments were placed in agitated shake flasks and samples were taken at different times to evaluate pH, SO{sub 4}{sup 2-} and Cr, Cu, Zn and Fe{sup 2+} concentration. Some of the systems were inoculated with an Acidithiobacillus ferrooxidans strain to assess the biological catalysis on sulphide oxidation. Results: Sediment chemical characterization showed high organic matter content (5.4-10.6%), total sulphur (0.36-0.86%) and equivalent CaCO{sub 3

  17. Principles for Effective ClassroomAssessment

    OpenAIRE

    Louis Volante

    2006-01-01

    Based on a synthesis of the research literature, seven principles for effective classroom assessment are presented. These principles included the need for classroom assessment to be student-centered, aligned with clear learning targets, based on multiple methods, able to account for a variety of student skills, aimed at reducing bias, reliable and valid, and efficient. The discussion addresses ways of promoting these principles at the pre-service and in-service levels and underscores the impo...

  18. Principles for Effective ClassroomAssessment

    Directory of Open Access Journals (Sweden)

    Louis Volante

    2006-01-01

    Full Text Available Based on a synthesis of the research literature, seven principles for effective classroom assessment are presented. These principles included the need for classroom assessment to be student-centered, aligned with clear learning targets, based on multiple methods, able to account for a variety of student skills, aimed at reducing bias, reliable and valid, and efficient. The discussion addresses ways of promoting these principles at the pre-service and in-service levels and underscores the importance of changing the current Western zeitgeist that diminishes the central importance of classroom assessment data.

  19. Assessment of infant exposure to food chemicals: the French Total Diet Study design.

    Science.gov (United States)

    Hulin, M; Bemrah, N; Nougadère, A; Volatier, J L; Sirot, V; Leblanc, J C

    2014-01-01

    As part of the previous French Total Diet Studies (TDS) focusing on exposure to food chemicals in the population aged 3 years and older, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) launched a specific TDS on infants to complete its overall chemical food safety programme for the general population. More than 500 chemical substances were analysed in food products consumed by children under 3 years old, including nutrients, several endocrine disruptors resulting from human activities (polychlorinated biphenyls, dioxins and furans, brominated flame retardants, perfluoroalkyl acids, pesticide residues, etc.) or migrating from food contact materials such as bisphenol A or phthalates, but also natural substances such as mycotoxins, phytoestrogens and steroids. To obtain a representative and general view of infant food consumption, food items were selected based on results of a national consumption survey conducted specifically on this population. Moreover, a specific study on food was conducted on 429 households to determine which home-cooking practices are employed to prepare food consumed by infants. Overall, the targeted chemical substances were analysed in more than 450 food samples, representing the purchase and home-cooking practices of over 5500 food products. Foods included common foods such as vegetables, fruit or cakes as well as specific infant foods such as infant formula or jarred baby food. The sampling plan covered over 80% of the total diet. Specificities in infant food consumption and habits were therefore considered to define this first infant TDS. This study, conducted on a large scale and focusing on a particularly sensitive population, will provide accurate information on the dietary exposure of children under 3 years to food chemicals, especially endocrine disruptors, and will be particularly useful for risk assessment analysis under the remit of ANSES' expert committees.

  20. Evidence of Non-local Chemical, Thermal and Gravitational Effects

    Directory of Open Access Journals (Sweden)

    Hu H.

    2007-04-01

    Full Text Available Quantum entanglement is ubiquitous in the microscopic world and manifests itself macroscopically under some circumstances. But common belief is that it alone cannot be used to transmit information nor could it be used to produce macroscopic non- local effects. Yet we have recently found evidence of non-local effects of chemical substances on the brain produced through it. While our reported results are under independent verifications by other groups, we report here our experimental findings of non-local chemical, thermal and gravitational effects in simple physical systems such as reservoirs of water quantum-entangled with water being manipulated in a remote reservoir. With the aids of high-precision instruments, we have found that the pH value, temperature and gravity of water in the detecting reservoirs can be non-locally affected through manipulating water in the remote reservoir. In particular, the pH value changes in the same direction as that being manipulated; the temperature can change against that of local environment; and the gravity apparently can also change against local gravity. These non-local effects are all reproducible and can be used for non-local signalling and many other purposes. We suggest that they are mediated by quantum entanglement between nuclear and/or electron spins in treated water and discuss the implications of these results.

  1. Doppler imaging of chemical spots on magnetic Ap/Bp stars. Numerical tests and assessment of systematic errors

    Science.gov (United States)

    Kochukhov, O.

    2017-01-01

    Context. Doppler imaging (DI) is a powerful spectroscopic inversion technique that enables conversion of a line profile time series into a two-dimensional map of the stellar surface inhomogeneities. DI has been repeatedly applied to reconstruct chemical spot topologies of magnetic Ap/Bp stars with the goal of understanding variability of these objects and gaining an insight into the physical processes responsible for spot formation. Aims: In this paper we investigate the accuracy of chemical abundance DI and assess the impact of several different systematic errors on the reconstructed spot maps. Methods: We have simulated spectroscopic observational data for two different Fe spot distributions with a surface abundance contrast of 1.5 dex in the presence of a moderately strong dipolar magnetic field. We then reconstructed chemical maps using different sets of spectral lines and making different assumptions about line formation in the inversion calculations. Results: Our numerical experiments demonstrate that a modern DI code successfully recovers the input chemical spot distributions comprised of multiple circular spots at different latitudes or an element overabundance belt at the magnetic equator. For the optimal reconstruction based on half a dozen spectral intervals, the average reconstruction errors do not exceed 0.10 dex. The errors increase to about 0.15 dex when abundance distributions are recovered from a few and/or blended spectral lines. Ignoring a 2.5 kG dipolar magnetic field in chemical abundance DI leads to an average relative error of 0.2 dex and maximum errors of 0.3 dex. Similar errors are encountered if a DI inversion is carried out neglecting a non-uniform continuum brightness distribution and variation of the local atmospheric structure. None of the considered systematic effects lead to major spurious features in the recovered abundance maps. Conclusions: This series of numerical DI simulations proves that inversions based on one or two spectral

  2. Assessment of fires in chemical warehouses. An overview of the TOXFIRE project

    DEFF Research Database (Denmark)

    1999-01-01

    The report summarises the scientific outcome of the CEC Environment project "TOXFIRE. Guidelines for Management of Fires in Chemical Warehouses". The project was performed in the period 1994 - 1996 in a multi-national co-operation between partners fromUnited Kingdom, Sweden, Finland and Denmark...... performed. Also included were items as fire modelling, risk assessment to human health and the environment. Finally, the basis of guidelines for safetyengineers and fire brigades were established. The report describes the work done by each partner and the main results achieved. The references of all reports...

  3. Normal mode Rossby waves and their effects on chemical composition in the late summer stratosphere

    Directory of Open Access Journals (Sweden)

    D. Pendlebury

    2007-08-01

    Full Text Available During past MANTRA campaigns, ground-based measurements of several long-lived chemical species have revealed quasi-periodic fluctuations on time scales of several days. These fluctuations could confound efforts to detect long-term trends from MANTRA, and need to be understood and accounted for. Using the Canadian Middle Atmosphere Model, we investigate the role of dynamical variability in the late summer stratosphere due to normal mode Rossby waves and the impact of this variability on fluctuations in chemical species. Wavenumber~1, westward travelling waves are considered with average periods of 5, 10 and 16 days. Time-lagged correlations between the temperature and nitrous oxide, methane and ozone fields are calculated in order to assess the possible impact of these waves on the chemical species, although transport may be the dominant effect. Using Fourier-wavelet decomposition and correlating the fluctuations between the temperature and chemical fields, we determine that variations in the chemical species are well-correlated with the 5-day wave and the 10-day wave between 30 and 60 km. Interannual variability of the waves is also examined.

  4. Steam system opportunity assessment for the pulp and paper, chemical manufacturing, and petroleum refining industries: Main report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2002-10-01

    This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

  5. Integrated assessment of sources, chemical stressors and stream quality along a groundwater fed stream system

    Science.gov (United States)

    Løgstrup Bjerg, Poul; Sonne, Anne T.; Rønde, Vinni; McKnight, Ursula S.

    2016-04-01

    Streams are impacted by significant contamination at the catchment scale, as they are often locations of multiple chemical stressor inputs. The European Water Framework Directive requires EU member states to ensure good chemical and ecological status of surface water bodies by 2027. This requires monitoring of stream water quality, comparison with environmental quality standards (EQS) and assessment of ecological status. However, the achievement of good status of stream water also requires a strong focus on contaminant sources, pathways and links to stream water impacts, so source management and remedial measures can be implemented. Fate and impacts of different contaminant groups are governed by different processes and are dependent on the origin (geogenic, anthropogenic), source type (point or diffuse) and pathway of the contaminant. To address this issue, we identified contaminant sources and chemical stressors on a groundwater-fed stream to quantify the contaminant discharges, link the chemical impact and stream water quality and assess the main chemical risk drivers in the stream system potentially driving ecological impact. The study was conducted in the 8 m wide Grindsted stream (Denmark) along a 16 km stream stretch that is potentially impacted by two contaminated sites (Grindsted Factory site, Grindsted Landfill), fish farms, waste water discharges, and diffuse sources from agriculture and urban areas. Water samples from the stream and the hyporheic zone as well as bed sediment samples were collected during three campaigns in 2012 and 2014. Data for xenobiotic organic groundwater contaminants, pesticides, heavy metals, general water chemistry, physical conditions and stream flow were collected. The measured chemical concentrations were converted to toxic units (TU) based on the 48h acute toxicity tests with D. magna. The results show a substantial impact of the Grindsted Factory site at a specific stretch of the stream. The groundwater plume caused

  6. The effect of the indoor environment on the fate of organic chemicals in the urban landscape

    Energy Technology Data Exchange (ETDEWEB)

    Cousins, Anna Palm, E-mail: anna.cousins@ivl.se

    2012-11-01

    To assess the effect of the indoor environment on the urban fate of organic chemicals, an 8-compartment indoor-inclusive steady state multimedia chemical fate model was developed. The model includes typical urban compartments (air, soil, water, sediment, and urban film) and a novel module representing a generic indoor environment. The model was parameterized to the municipality of Stockholm, Sweden and applied to four organic chemicals with different physical-chemical characteristics and use patterns: formaldehyde, 2,4,6-tribromophenol, di-ethylhexylphthalate and decabromodiphenyl ether. The results show that emissions to indoor air may increase the steady state mass and residence time in the urban environment by a factor of 1.1 to 22 for the four chemicals, compared to if emissions are assigned to outdoor air. This is due to the nested nature of the indoor environment, which creates a physical barrier that prevents chemicals from leaving the urban system with outflowing air. For DEHP and BDE 209, the additional partitioning to indoor surfaces results in a greater importance of the indoor removal pathways from surfaces. The outdoor environmental concentrations of these chemicals are predicted to be lower if emitted to indoor air than if emitted to outdoor air because of the additional indoor removal pathways of dust and indoor film, leading to loss of chemical from the system. For formaldehyde and 2,4,6-TBP outdoor environmental concentrations are not affected by whether the release occurs indoors or outdoors because of the limited partitioning to indoor surfaces. A sensitivity analysis revealed that there appears to be a relationship between logK{sub OA} and the impact of the ventilation rate on the urban fate of organic chemicals. -- Highlights: Black-Right-Pointing-Pointer A novel indoor-inclusive multimedia urban fate model is developed and applied. Black-Right-Pointing-Pointer Emissions indoors may increase the urban chemical residence time. Black

  7. Dermal permeation data and models for the prioritization and screening-level exposure assessment of organic chemicals

    Science.gov (United States)

    High throughput screening (HTS) models are being developed and applied to prioritize chemicals for more comprehensive exposure and risk assessment. Dermal pathways are possible exposure routes to humans for thousands of chemicals found in personal care products and the indoor env...

  8. Risk assessment of chemicals in food and diet: Hazard identification by methods of animal-based toxicology

    DEFF Research Database (Denmark)

    Barlow, S. M.; Greig, J. B.; Bridges, J. W.;

    2002-01-01

    the current state of the science of risk assessment of chemicals in food and diet, by consideration of the four stages of risk assessment, that is. hazard identification. hazard characterisation, exposure assessment and risk characterisation. The contribution of animal-based methods in toxicology to hazard......, on hazard identification for food chemicals, such as new measurement techniques, the use of transgenic animals, assessment of hormone balance and the possibilities for conducting studies in which common human diseases have been modelled. is also considered. (C) 2002 ILSI. Published by Elsevier Science Ltd....... All rights reserved....

  9. [Emission characteristics and hazard assessment analysis of volatile organic compounds from chemical synthesis pharmaceutical industry].

    Science.gov (United States)

    Li, Yan; Wang, Zhe-Ming; Song, Shuang; Xu, Zhi-Rong; Xu, Ming-Zhu; Xu, Wei-Li

    2014-10-01

    In this study, volatile organic compounds (VOCs) released from chemical synthesis pharmaceutical industry in Taizhou, Zhejiang province were analyzed quantitatively and qualitatively. The total volatile organic compounds (TVOCs) was in the range of 14.9-308.6 mg · m(-3). Evaluation models of ozone formation potentials (OFP) and health risk assessment were adopted to preliminarily assess the environmental impact and health risk of VOCs. The results showed that the values of OFP of VOCs were in the range of 3.1-315.1 mg · m(-3), based on the maximum incremental reactivity, the main principal contribution was toluene, tetrahydrofuran (THF), acetic ether etc. The non-carcinogenic risk and the carcinogen risk fell in the ranges of 9.48 x 10(-7)-4.98 x 10(-4) a(-1) and 3.17 x 10(-5)- 6.33 x 10(-3). The principal contribution of VOCs was benzene, formaldehyde and methylene chloride.

  10. Environmental impact assessment: chemical explosive fracturing project, Petroleum Technology Corporation, Leslie, Letcher and Perry counties, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Tonnessen, K.A.

    1977-05-19

    This review of the plans for a gas stimulation program by chemical explosive fracturing (CEF) in the Devonian shales of Letcher, Leslie and Perry counties, Kentucky also includes an assessment of the environmental consequences of the proposed project. This document was prepared at the request of the Nevada Operations Office of the Energy Research and Development Administration, and is intended to provide the information and data required for the preparation of an environmental assessment of the construction and testing program. This report was compiled from material provided by the Petroleum Technology Corporation of Redmond, Washington, Kentucky-West Virginia Gas Transmission Corporation of Prestonsburg, Kentucky and the State of Kentucky Bureau of Mines and Minerals during site visits in October, 1976.

  11. Assessment of the chemical, microbiological and toxicological aspects of post-processing water from underground coal gasification.

    Science.gov (United States)

    Pankiewicz-Sperka, Magdalena; Stańczyk, Krzysztof; Płaza, Grażyna A; Kwaśniewska, Jolanta; Nałęcz-Jawecki, Grzegorz

    2014-10-01

    The purpose of this paper is to provide a comprehensive characterisation (including chemical, microbiological and toxicological parameters) of water after the underground coal gasification (UCG) process. This is the first report in which these parameters were analysed together to assess the environmental risk of the water generated during the simulation of the underground coal gasification (UCG) process performed by the Central Mining Institute (Poland). Chemical analysis of the water indicated many hazardous chemical compounds, including benzene, toluene, ethylbenzene, xylene, phenols and polycyclic aromatic hydrocarbons (PAHs). Additionally, large quantities of inorganic compounds from the coal and ashes produced during the volatilisation process were noted. Due to the presence of refractory and inhibitory compounds in the post-processing water samples, the microbiological and toxicological analyses revealed the high toxicity of the UCG post-processing water. Among the tested microorganisms, mesophilic, thermophilic, psychrophilic, spore-forming, anaerobic and S-oxidizing bacteria were identified. However, the number of detected microorganisms was very low. The psychrophilic bacteria dominated among tested bacteria. There were no fungi or Actinomycetes in any of the water samples. Preliminary study revealed that hydrocarbon-oxidizing bacteria were metabolically active in the water samples. The samples were very toxic to the biotests, with the TU50 reaching 262. None of biotests was the most sensitive to all samples. Cytotoxicity and genotoxicity testing of the water samples in Vicia uncovered strong cytotoxic and clastogenic effects. Furthermore, TUNEL indicated that all of the water samples caused sporadic DNA fragmentation in the nuclei of the roots.

  12. Water Quality Assessment Using Physico-Chemical Parameters and Heavy Metals of Gobind Sagar Lake, Himachal Pradesh (India

    Directory of Open Access Journals (Sweden)

    Vandana Sharma

    2015-12-01

    Full Text Available Today the environment has become harmful for the health of living organisms due to excessive pollution and contamination of natural resources. The present investigation has been carried out with the objective to assess the water quality of the Gobind Sagar Lake, Bilaspur, Himachal Pradesh (India using physico-chemical parameters with heavy metals of the lake. For this study, three sampling sites were identified and samples from different sites were collected in summer season and important parameters [Water Temperature , pH, Total Hardness, Dissolved Carbon Dioxide (CO2, Dissolved Oxygen (DO, Chemical Oxygen Demand (COD, Biological Oxygen Demand (BOD, Chloride, Total Alkalinity, Total Dissolved Solid (TDS] with heavy metals [ Lead (P, Copper (Co, Iron (Fe, Cadmium (Cd, Nickel (Ni and Manganese (Mn, Chromium (Cr were analyzed. The results revealed that the different conditions of Gobind Sagar Lake in different sampling stations showed fluctuations in some physico-chemical parameters and also in heavy metals. These result depicted that water of lake was polluted in the form of nutrient enrichment which is due to agricultural activities and its runoff in and around catchment area of the lake. There are other many ways that things can end up in the lake as the free style way of disposal of industrial and domestic effluents etc. Results of studies on heavy metals in pollution are well documented revealing the toxic effects of these metals on aquatic organisms.

  13. DNA Methylation Pyrosequencing Assay Is Applicable for the Assessment of Epigenetic Active Environmental or Clinical Relevant Chemicals

    Directory of Open Access Journals (Sweden)

    Ana-Maria Florea

    2013-01-01

    Full Text Available 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.

  14. EFFECT OF SCREW EXTRUSION PRETREATMENT ON PULPS FROM CHEMICAL PULPING

    Directory of Open Access Journals (Sweden)

    Cuihua Dong,

    2012-07-01

    Full Text Available The effect of compressive pretreatment before chemical pulping on the properties of poplar kraft and soda-AQ pulp was evaluated. Compressive pretreatment not only resulted in the dissolution of hemicellulose, but also leached extractives. Pulps made from compressive pretreated wood chips required lower beating energy than the untreated pulps to achieve the same beating degree of 45°SR, and the brightness of the handsheets was improved by 2% ISO. Compressive pretreatment allowed for efficient delignification and saved about 6% alkali consumption to achieve similar pulp screen yield. Furthermore, a higher content of fines and slightly lower mechanical properties were observed after the compressive treatment.

  15. Effects of Chemical Treatments on Microbiologically Influenced Corrosion

    Science.gov (United States)

    Friedman, E. S.; Strom, M.; Dexter, S. C.

    2008-12-01

    Biofilms are known to have an effect on galvanic corrosion of alloys in seawater systems. In the Delaware Bay, biofilm formation on surface of cathodes has been shown to cause galvanic corrosion to occur up to 100 times more rapidly. Given the impacts that corrosion can have on structures, it is important to study how we can affect corrosion rates. One way of doing this is the application of chemical treatments to biofilms on metal samples. To investigate this, natural marine biofilms were grown on alloy 6XN stainless steel samples, and various chemical treatments were applied to discover their effects on open circuit potentials and corrosion currents. Another objective of this study was to determine if there was a threshold molecular weight above which molecules were unable to penetrate the biofilm. It was discovered that chemicals with molecular weights as high as 741.6 g/mol were able to penetrate at least some parts of the heterogeneous biofilm and reach the metal surface. No upper threshold value was found in this study. It was found that the reducing agents sodium L-ascorbate and NADH as well as the chelate ferizene caused a drop in open circuit potential of biofilmed 6XN samples. Also, glutaraldahyde, which is used as a fixative for bacteria, shifted the open circuit potential of biofilm samples in the noble direction but had no effect on the corrosion current. Sodium L- ascorbate was found to reach the metal surface, but in concentrations lower than those present in the bulk fluid. It was not determined in this study whether this was due to physical or chemical processes within the biofilm. A synergistic effect was observed when applying a mixture of ferizene and glutaraldahyde. It is thought that this was due to the death of the bacteria as well as the disruption of iron cycling in the biofilm. Finally, it was observed that NADH caused a reduction in current at potentials associated with iron reduction, leading us to believe that the iron was being reduced

  16. Protective effect of silymarin against chemical-induced cardiotoxicity

    Directory of Open Access Journals (Sweden)

    Bibi Marjan Razavi

    2016-09-01

    Full Text Available Cardiac disorders remain one of the most important causes of death in the world. Oxidative stress has been suggested as one of the molecular mechanisms involved in drug-induced cardiac toxicity. Recently, several natural products have been utilized in different studies with the aim to protect the progression of oxidative stress-induced cardiac disorders. There is a large body of evidence that administration of antioxidants may be useful in ameliorating cardiac toxicity. Silymarin, a polyphenolic flavonoid has been shown to have utility in several cardiovascular disorders. In this review, various studies in scientific databases regarding the preventive effects of silymarin against cardiotoxicity induced by chemicals were introduced. Although there are many studies representing the valuable effects of silymarin in different diseases, the number of researches relating to the possible cardiac protective effects of silymarin against drugs induced toxicity is rather limited. Results of these studies show that silymarin has a broad spectrum of cardiac protective activity against toxicity induced by some chemicals including metals, environmental pollutants, oxidative agents and anticancer drugs. Further studies are needed to establish the utility of silymarin in protection against cardiac toxicity.

  17. [Assessment of the relationship of properties of chemical compounds and their toxicity to a unified hygienic standardization for chemicals].

    Science.gov (United States)

    Trushkov, V F; Perminov, K A; Sapozhnikova, V V; Ignatova, O L

    2013-01-01

    The connection of thermodynamic properties and parameters of toxicity of chemical substances was determined. Obtained data are used for the evaluation of toxicity and hygienic rate setting of chemical compounds. The relationship between enthalpy and toxicity of chemical compounds has been established. Orthogonal planning of the experiment was carried out in the course of the investigations. Equation of unified hygienic rate setting in combined, complex, conjunct influence on the organism is presented. Prospects of determination of toxicity and methodology of unified hygienic rate setting in combined, complex, conjunct influence on the organism are presented

  18. Toxicological and chemical assessment of arsenic-contaminated groundwater after electrochemical and advanced oxidation treatments.

    Science.gov (United States)

    Radić, Sandra; Crnojević, Helena; Vujčić, Valerija; Gajski, Goran; Gerić, Marko; Cvetković, Želimira; Petra, Cvjetko; Garaj-Vrhovac, Vera; Oreščanin, Višnja

    2016-02-01

    Owing to its proven toxicity and mutagenicity, arsenic is regarded a principal pollutant in water used for drinking. The objective of this study was the toxicological and chemical evaluation of groundwater samples obtained from arsenic enriched drinking water wells before and after electrochemical and ozone-UV-H2O2-based advanced oxidation processes (EAOP). For this purpose, acute toxicity test with Daphnia magna and chronic toxicity test with Lemna minor L. were employed as well as in vitro bioassays using human peripheral blood lymphocytes (HPBLs). Several oxidative stress parameters were estimated in L.minor. Physicochemical analysis showed that EAOP treatment was highly efficient in arsenic but also in ammonia and organic compound removal from contaminated groundwater. Untreated groundwater caused only slight toxicity to HPBLs and D. magna in acute experiments. However, 7-day exposure of L. minor to raw groundwater elicited genotoxicity, a significant growth inhibition and oxidative stress injury. The observed genotoxicity and toxicity of raw groundwater samples was almost completely eliminated by EAOP treatment. Generally, the results obtained with L. minor were in agreement with those obtained in the chemical analysis suggesting the sensitivity of the model organism in monitoring of arsenic-contaminated groundwater. In parallel to chemical analysis, the implementation of chronic toxicity bioassays in a battery is recommended in the assessment of the toxic and genotoxic potential of such complex mixtures.

  19. Application of infrared spectroscopy for assessing quality (chemical composition) of peatland plants, litter and soil

    Science.gov (United States)

    Straková, Petra; Laiho, Raija

    2016-04-01

    In this presentation, we assess the merits of using Fourier transform infrared (FTIR) spectra to estimate the organic matter composition in different plant biomass and peat soil samples. Infrared spectroscopy has a great potential in large-scale peatland studies that require low cost and high throughput techniques, as it gives a unique "chemical overview" of a sample, with all the chemical compounds present contributing to the spectrum produced. Our extensive sample sets include soil samples ranging from boreal to tropical peatlands, including sites under different environmental and/or land-use changes; above- and below-ground biomass of different peatland plant species; plant root mixtures. We mainly use FTIR to estimate (1) chemical composition of the samples (e.g., total C and N, C:N ratio, holocellulose, lignin and ash content), (2) proportion of each plant species in root mixtures, and (3) respiration of surface peat. The satisfactory results of our predictive models suggest that this experimental approach can, for example, be used as a screening tool in the evaluation of organic matter composition in peatlands during monitoring of their degradation and/or restoration success.

  20. Assessing the Impact of Capture on Wild Animals: The Case Study of Chemical Immobilisation on Alpine Ibex.

    Directory of Open Access Journals (Sweden)

    Francesca Brivio

    Full Text Available The importance of capturing wild animals for research and conservation projects is widely shared. As this activity continues to become more common, the need to assess its negative effects increases so as to ensure ethical standards and the validity of research results. Increasing evidence has revealed that indirect (physiological and behavioural effects of capture are as important as direct risks (death or injury and that different capture methodologies can cause heterogeneous effects. We investigated the influence of chemical immobilisation on Alpine ibex (Capra ibex: during the days following the capture we collected data on spatial behaviour, activity levels of both males and females, and male hormone levels. Moreover, we recorded the reproductive status of each marked female during the breeding seasons of 15 years. Then, by several a priori models we investigated the effects of the capture taking into account biological factors and changes in environmental conditions. Our results showed that chemical immobilisation did not affect either spatial behaviour (for both males and females or male hormone levels, though both sexes showed reduced activity levels up to two days after the capture. The capture did not significantly affect the likelihood for a female to give birth in the following summer. Our findings highlighted the scarce impact of chemical immobilisation on ibex biology, as we detected alteration of activity levels only immediately after the capture if compared to the following days (i.e., baseline situation. Hence, the comparison of our findings with previous research showed that our methodology is one of the less invasive procedures to capture large mammals. Nonetheless, in areas characterised by high predator density, we suggest that animals released be carefully monitored for some hours after the capture. Moreover, researchers should avoid considering data collected during the first days after the manipulation in order to avoid

  1. Assessing the Impact of Capture on Wild Animals: The Case Study of Chemical Immobilisation on Alpine Ibex.

    Science.gov (United States)

    Brivio, Francesca; Grignolio, Stefano; Sica, Nicoletta; Cerise, Stefano; Bassano, Bruno

    2015-01-01

    The importance of capturing wild animals for research and conservation projects is widely shared. As this activity continues to become more common, the need to assess its negative effects increases so as to ensure ethical standards and the validity of research results. Increasing evidence has revealed that indirect (physiological and behavioural) effects of capture are as important as direct risks (death or injury) and that different capture methodologies can cause heterogeneous effects. We investigated the influence of chemical immobilisation on Alpine ibex (Capra ibex): during the days following the capture we collected data on spatial behaviour, activity levels of both males and females, and male hormone levels. Moreover, we recorded the reproductive status of each marked female during the breeding seasons of 15 years. Then, by several a priori models we investigated the effects of the capture taking into account biological factors and changes in environmental conditions. Our results showed that chemical immobilisation did not affect either spatial behaviour (for both males and females) or male hormone levels, though both sexes showed reduced activity levels up to two days after the capture. The capture did not significantly affect the likelihood for a female to give birth in the following summer. Our findings highlighted the scarce impact of chemical immobilisation on ibex biology, as we detected alteration of activity levels only immediately after the capture if compared to the following days (i.e., baseline situation). Hence, the comparison of our findings with previous research showed that our methodology is one of the less invasive procedures to capture large mammals. Nonetheless, in areas characterised by high predator density, we suggest that animals released be carefully monitored for some hours after the capture. Moreover, researchers should avoid considering data collected during the first days after the manipulation in order to avoid biased

  2. Assessing the authenticity of commercial deep-sea drinking water by chemical and isotopic approaches.

    Science.gov (United States)

    Peng, Tsung-Ren; Liang, Wen-Jui; Liu, Tsang-Sen; Lin, Yu-Wen; Zhan, Wen-Jun

    2015-01-01

    This study combines stable isotopes and chemical elements with statistical principal component analysis (PCA) to assess the authenticity of bottled commercial drinking water desalinized from deep seawater in the Taiwan market. Isotopic results indicate that true bottled deep-sea drinking water (DSDW) exhibits about 0 ‰ for both δ(2)H and δ(18)O values, which are values similar to those of open seawater. By comparison, suspected counterfeit DSDW products display δ(2)H and δ(18)O values of around -51 ‰ and -8 ‰, respectively. These values are representative of terrestrial freshwater. In addition, suspected counterfeit DSDWs have δ and electrical conductivity values similar to a mixed water (MW) product that was manufactured by purifying terrestrial freshwater and adulterating this with small amounts of brine. Furthermore, PCA results indicate the chemical constitution of suspected DSDW products to be similar to the MW product which falls between purified terrestrial freshwater and desalinized open seawater. These similarities imply that suspected counterfeit DSDW products are manufactured in a similar manner to the declared MW product. This study demonstrates how combining knowledge of stable water isotopes and PCA can be used in assessing the authenticity of commercial DSDW products. The method should be of great interest to similar investigations elsewhere.

  3. Chemical and radiolytical characterization of perfluorocarbon fluids used as coolants for LHC experiments : radiolysis effects in perfluorohexane fluids.

    CERN Document Server

    Ilie, Soran; Teissandier, B; CERN. Geneva. TS Department

    2007-01-01

    Perfluorohexane fluids, used as coolants within High Energy Physics Detectors in the Large Hadrons Collider (LHC) at CERN, were irradiated using gammas 60Co and characterized using different analytical techniques. The aim of this work was the assessment of radiation induced effects as a function of the chemical nature of these fluids and their impurity content. Were evidenced the radioinduced polymers and acidity, as well as different chemical by-products. Purification tests and measurements were carried out on different irradiated fluid samples to assess the efficiency of such purification treatments in view of their re-use in the HEP detector cooling systems.

  4. ARIES: System for Health effects Assessment in industrial risk

    Energy Technology Data Exchange (ETDEWEB)

    Rabago, I.; Vidania, R. de; Inmaculada, S.

    1992-07-01

    In this work we present a general description of ARIES*, a tool designed in order to support the assessment of expected health effects derived from an accidental release of toxic compounds. ARIES includes two sequential and complementary steps. The first one (a quantitative phase) is being developed. for inhalation exposures, using numerical models, empirical correlations, physiological parameters and toxicological index, to estimate short term consequences over the exposed population. Next it will be published a new report were It will be described with detail the procedure designed to the quantitative assessment of the exposure. The system starts the assessment process with values of external concentrations which are processed, together with different exposure values (existing for humans and scaled up irom animals), as inputs for different kinds of models. From these, and other physiological values ARIES calculates the inhaled equivalent doses and the expected associated effects as a function of the exposure limes. Once overcome this first step, ARIES is complemented with an additional system that executes the selection of relevant information from toxicological data bases (qualitative phase). The system works , applying a string of filters and searches that displays selected Information, giving an additional support to the assessment. Both steps, just referred, are integrated into a logical informatics support. The informatics code is developed in dbase language even for the design of the procedure as for the mathematical models linked to the system ( extrapolation, dose inhaled models, etc.) to execute the numerical analysis of the assessment. The system has been designed in order to include progressively new chemicals and the improvements obtained in the development of mathematical models related with dose-effect relationships. At this moment, is programmed a first prototype of ARIES that can be executed in PC's and it can run for several products

  5. The Toxicology of Chemical Mixtures Risk Assessment for Human and Ecological Receptors

    Science.gov (United States)

    2005-10-01

    AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) kir Force Materiel Command*** HEPB kir Force Research Laboratory iuman Effectiveness... cancer slope factor) as are used for individual chemicals, so the calculations are relatively simple and familiar (U.S. EPA, 2000). Of course, the same...skin painting assays served as the short term assay; human lung cancer epidemiological data were available for roofing tar and coke oven emissions

  6. AB159. Endocrine disrupting chemicals: toxicological risk assessment in vivo and in vitro models

    OpenAIRE

    Thuy, Vo Thi Bich; Nguyen Binh, Le Thi; Phuong Oanh, Kim Thi; Van Hai, Nong

    2015-01-01

    In several studies, scientists asserted that many of endocrine disruptors (EDs), which have been involved in developmental, reproductive, neural, immunological, and other problems in wildlife and laboratory animals. Some environmental EDs, such as di-(2-ethylhexyl) phthalate (DEHP), flutamide (Flu), parabens, are used in many products in life and environment. However, the adverse effects caused by EDs can be temporary or permanent and the mechanism(s) through which these chemicals elicit thei...

  7. Intercomparison of chemical mechanisms for air quality policy formulation and assessment under North American conditions.

    Science.gov (United States)

    Derwent, Richard

    2017-02-22

    The intercomparison of seven chemical mechanisms for their suitability for air quality policy formulation and assessment is described. Box modelling techniques were employed using 44 sets of background environmental conditions covering North America to constrain the chemical development of the longer-lived species. The selected mechanisms were modified to enable an unbiased assessment of the adequacy of the parameterisations of photochemical ozone production from VOC oxidation in the presence of NOx. Photochemical ozone production rates responded differently to 30% NOx and VOC reductions with the different mechanisms, despite the striking similarities between the base case ozone production rates. The 30% reductions in NOx and VOCs also produced changes in OH. The responses in OH to 30% reductions in NOx and VOCs appeared to be more sensitive to mechanism choice, compared with the responses in the photochemical ozone production rates. Whereas 30% NOx reductions generally led to decreases in OH, 30% reductions in VOCs led to increases in OH, irrespective of mechanism choice and background environmental conditions. The different mechanisms therefore gave different OH responses to NOx and VOC reductions and so would give different responses in terms of changes in the fate and behaviour of air toxics, acidification and eutrophication and fine particle formation compared with others, in response to ozone control strategies. Policy-makers need to understand that there are likely to be inherent differences in the responses to ozone control strategies between different mechanisms, depending on background environmental conditions and the extents of NOx and VOC reductions under consideration. IMPLICATIONS The purpose of this paper is to compare predicted ozone responses to NOx and VOC reductions with seven chemical mechanisms under North American conditions. The good agreement found between the tested mechanisms should provide some support for their application in the air

  8. Effects of Biofertilizer Application Method with Integrated Chemical Fertilizers on Maize Production and Some Chemical Characteristics of Soil

    Directory of Open Access Journals (Sweden)

    F Ebrahimpour

    2012-07-01

    Full Text Available In order to study the effects of integrated application of bio-fertilizer and chemical fertilizers on yield and yield components of corn, an experiment was conducted in 2008 in Dezful city, (Khoozestan province in a factorial arrangement based on complete randomized block design with four replications. Treatments were integrated application of biological and chemical fertilizers in four levels (100% chemical fertilizer, 50% chemical fertilizer+ bio-fertilizer, 25% chemical fertilizer + bio-fertilizer and bio-fertilizer and bio-fertilizer application method in three levels (seed inoculation, fertigation, seed inoculation+fertigation. The results showed that highest and the lowest grain yield was obtained by application of 50% chemical fertilizer+ bio-fertilizer (10.7 t/ha and bio-fertilizer (5.2 t/ha, respectively. The greatest and the lowest harvest indices were recorded in chemical (0.59 and bio-fertilizer (0.45 treatments, respectively. Number of grain per row and row in ear had not significant differences in integrated and chemical treatments. Methods of bio-fertilizer application had not significant effect on maize yield and yield components. The results of soil analysis showed that bio-fertilizers increased P, K as well as other macro elements availability rather than N. The results revealed that although replacing chemical fertilizers by bio-fertilizers reduced maize growth, but integrated application of these sources produced highest grain yield, nitration elements availability and reduced substantially consumption of fertilizer. The results also indicated that non-chemical sources of crop nutrients can be considered as a reliable alternative for chemical fertilization in ecological production of crops in agro-ecosystems of Iran.

  9. Effects of the EVCAM chemical validation library on differentiation using marker gene expression in lmouse embryonic stem cells

    Science.gov (United States)

    The adherent cell differentiation and cytotoxicity (ACDC) assay was used to profile the effects of the ECVAM EST validation chemical library (19 compounds) on J1 mouse embryonic stem cells (mESC). PCR-based TaqMan Low Density Arrays (TLDA) provided a high-content assessment of al...

  10. History of EPI Suite™ and future perspectives on chemical property estimation in US Toxic Substances Control Act new chemical risk assessments.

    Science.gov (United States)

    Card, Marcella L; Gomez-Alvarez, Vicente; Lee, Wen-Hsiung; Lynch, David G; Orentas, Nerija S; Lee, Mari Titcombe; Wong, Edmund M; Boethling, Robert S

    2017-03-22

    Chemical property estimation is a key component in many industrial, academic, and regulatory activities, including in the risk assessment associated with the approximately 1000 new chemical pre-manufacture notices the United States Environmental Protection Agency (US EPA) receives annually. The US EPA evaluates fate, exposure and toxicity under the 1976 Toxic Substances Control Act (amended by the 2016 Frank R. Lautenberg Chemical Safety for the 21(st) Century Act), which does not require test data with new chemical applications. Though the submission of data is not required, the US EPA has, over the past 40 years, occasionally received chemical-specific data with pre-manufacture notices. The US EPA has been actively using this and publicly available data to develop and refine predictive computerized models, most of which are housed in EPI Suite™, to estimate chemical properties used in the risk assessment of new chemicals. The US EPA develops and uses models based on (quantitative) structure-activity relationships ([Q]SARs) to estimate critical parameters. As in any evolving field, (Q)SARs have experienced successes, suffered failures, and responded to emerging trends. Correlations of a chemical structure with its properties or biological activity were first demonstrated in the late 19(th) century and today have been encapsulated in a myriad of quantitative and qualitative SARs. The development and proliferation of the personal computer in the late 20(th) century gave rise to a quickly increasing number of property estimation models, and continually improved computing power and connectivity among researchers via the internet are enabling the development of increasingly complex models.

  11. Energy Effectiveness Assessment of Composting Technologies

    OpenAIRE

    Plūme, I.

    2006-01-01

    The incorrect biomass composting improperly results in considerable emission of greenhouse gases, loss of effluent and composting heat into environment. The composting heat and gases utilisation is especially suitable for plant enrichment and heating of greenhouses. The mathematical model is worked out for assessment of energy effectiveness and sustainability of biomass composting process. Coefficient of energy effectiveness for traditional litter manure composting technologies is 0.45 and ca...

  12. Neurological effects on startle response and escape from predation by medaka exposed to organic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, R.; Drummond, R.; Hammermeister, D.; Bradbury, S. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1995-12-31

    Simultaneous electrophysiological and behavioral studies were performed on juvenile Japanese medaka (Oryzias latipes) exposed to representative neurotoxic organic chemicals at sublethal concentrations. Non-invasive recordings were made of the electrical impulses generated within giant neuronal Mauthner cells, associated interneurons or motoneurons, and musculature, all of which initiate the startle or escape response in fish. Timing in milliseconds between these electrical sequelae was measured for each fish before and at 24 and 48 hours exposure to a chemical. Also noted was the number of startle responses to number of stimuli ratio (R/S). Other groups of medaka were fed to bluegills and consumption times recorded to assess their ability to escape predation. These results were compared to neurophysiological effect levels. Phenol, 2,4-dinitrophenol, chlorpyrifos, fenvalerate, and 1-octanol impaired the ability of medaka to escape predation at all concentrations. Medaka were more susceptible to predation in high concentrations of carbaryl and strychnine, but less susceptible at low concentrations, whereas the reverse was true for endosulfan. The variety of neurological effects detected at these concentrations suggest that different mechanisms may be responsible. Phenol and strychnine affected Mauthner cell to motoneuron transmission, chlorpyrifos and carbaryl showed neuromuscular effects, and R/S was affected by most chemicals. Although a variety of neurotoxic mechanisms were examined, the exposure threshold for significant effects for each specific compound was found to be consistent for both the neurophysiological and behavioral endpoints.

  13. Toward the definition of specific protection goals for the environmental risk assessment of chemicals: A perspective on environmental regulation in Europe.

    Science.gov (United States)

    Brown, A Ross; Whale, Graham; Jackson, Mathew; Marshall, Stuart; Hamer, Mick; Solga, Andreas; Kabouw, Patrick; Galay-Burgos, Malyka; Woods, Richard; Nadzialek, Stephanie; Maltby, Lorraine

    2017-01-01

    This critical review examines the definition and implementation of environmental protection goals for chemicals in current European Union (EU) legislation, guidelines, and international agreements to which EU countries are party. The European chemical industry is highly regulated, and prospective environmental risk assessments (ERAs) are tailored for different classes of chemical, according to their specific hazards, uses, and environmental exposure profiles. However, environmental protection goals are often highly generic, requiring the prevention of "unacceptable" or "adverse" impacts on "biodiversity" and "ecosystems" or the "environment as a whole." This review aims to highlight working examples, challenges, solutions, and best practices for defining specific protection goals (SPGs), which are seen to be essential for refining and improving ERA. Specific protection goals hinge on discerning acceptable versus unacceptable adverse effects on the key attributes of relevant, sensitive ecological entities (ranging from organisms to ecosystems). Some isolated examples of SPGs for terrestrial and aquatic biota can be found in prospective ERA guidance for plant protection products (PPPs). However, SPGs are generally limited to environmental or nature legislation that requires environmental monitoring and retrospective ERA. This limitation is due mainly to the availability of baselines, which define acceptable versus unacceptable environmental effects on the key attributes of sentinel species, populations and/or communities, such as reproductive status, abundance, or diversity. Nevertheless, very few regulatory case examples exist in which SPGs incorporate effect magnitude, spatial extent, and temporal duration. We conclude that more holistic approaches are needed for defining SPGs, particularly with respect to protecting population sustainability, ecosystem function, and integrity, which are implicit in generic protection goals and explicit in the International

  14. Metabolomic Assessment of Induced and Activated Chemical Defence in the Invasive Red Alga Gracilaria vermiculophylla

    Science.gov (United States)

    Nylund, Göran M.; Weinberger, Florian; Rempt, Martin; Pohnert, Georg

    2011-01-01

    In comparison with terrestrial plants the mechanistic knowledge of chemical defences is poor for marine macroalgae. This restricts our understanding in the chemically mediated interactions that take place between algae and other organisms. Technical advances such as metabolomics, however, enable new approaches towards the characterisation of the chemically mediated interactions of organisms with their environment. We address defence responses in the red alga Gracilaria vermiculophylla using mass spectrometry based metabolomics in combination with bioassays. Being invasive in the north Atlantic this alga is likely to possess chemical defences according to the prediction that well-defended exotics are most likely to become successful invaders in systems dominated by generalist grazers, such as marine macroalgal communities. We investigated the effect of intense herbivore feeding and simulated herbivory by mechanical wounding of the algae. Both processes led to similar changes in the metabolic profile. Feeding experiments with the generalist isopod grazer Idotea baltica showed that mechanical wounding caused a significant increase in grazer resistance. Structure elucidation of the metabolites of which some were up-regulated more than 100 times in the wounded tissue, revealed known and novel eicosanoids as major components. Among these were prostaglandins, hydroxylated fatty acids and arachidonic acid derived conjugated lactones. Bioassays with pure metabolites showed that these eicosanoids are part of the innate defence system of macroalgae, similarly to animal systems. In accordance with an induced defence mechanism application of extracts from wounded tissue caused a significant increase in grazer resistance and the up-regulation of other pathways than in the activated defence. Thus, this study suggests that G. vermiculophylla chemically deters herbivory by two lines of defence, a rapid wound-activated process followed by a slower inducible defence. By unravelling

  15. Metabolomic assessment of induced and activated chemical defence in the invasive red alga Gracilaria vermiculophylla.

    Directory of Open Access Journals (Sweden)

    Göran M Nylund

    Full Text Available In comparison with terrestrial plants the mechanistic knowledge of chemical defences is poor for marine macroalgae. This restricts our understanding in the chemically mediated interactions that take place between algae and other organisms. Technical advances such as metabolomics, however, enable new approaches towards the characterisation of the chemically mediated interactions of organisms with their environment. We address defence responses in the red alga Gracilaria vermiculophylla using mass spectrometry based metabolomics in combination with bioassays. Being invasive in the north Atlantic this alga is likely to possess chemical defences according to the prediction that well-defended exotics are most likely to become successful invaders in systems dominated by generalist grazers, such as marine macroalgal communities. We investigated the effect of intense herbivore feeding and simulated herbivory by mechanical wounding of the algae. Both processes led to similar changes in the metabolic profile. Feeding experiments with the generalist isopod grazer Idotea baltica showed that mechanical wounding caused a significant increase in grazer resistance. Structure elucidation of the metabolites of which some were up-regulated more than 100 times in the wounded tissue, revealed known and novel eicosanoids as major components. Among these were prostaglandins, hydroxylated fatty acids and arachidonic acid derived conjugated lactones. Bioassays with pure metabolites showed that these eicosanoids are part of the innate defence system of macroalgae, similarly to animal systems. In accordance with an induced defence mechanism application of extracts from wounded tissue caused a significant increase in grazer resistance and the up-regulation of other pathways than in the activated defence. Thus, this study suggests that G. vermiculophylla chemically deters herbivory by two lines of defence, a rapid wound-activated process followed by a slower inducible

  16. Additive mixture effects of estrogenic chemicals in human cell-based assays can be influenced by inclusion of chemicals with differing effect profiles.

    Directory of Open Access Journals (Sweden)

    Richard Mark Evans

    Full Text Available A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX and cell proliferation (ESCREEN endpoints. Two mixture designs were used: 1 a 'balanced' design with components present in proportion to a common effect concentration (e.g. an EC(10 and 2 a 'non-balanced' design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential

  17. Human and animal health risk assessments of chemicals in the food chain: Comparative aspects and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Dorne, J.L.C.M., E-mail: jean-lou.dorne@efsa.europa.eu [Emerging Risk Unit, Via Carlo Magno 1A, 43126 Parma (Italy); Fink-Gremmels, J. [Utrecht University, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Yalelaan 104, 3584 CM Utrecht (Netherlands)

    2013-08-01

    Chemicals from anthropogenic and natural origins enter animal feed, human food and water either as undesirable contaminants or as part of the components of a diet. Over the last five decades, considerable efforts and progress to develop methodologies to protect humans and animals against potential risks associated with exposure to such potentially toxic chemicals have been made. This special issue presents relevant methodological developments and examples of risk assessments of undesirable substances in the food chain integrating the animal health and the human health perspective and refers to recent Opinions of the Scientific Panel on Contaminants in the Food Chain (CONTAM) of the European Food Safety Authority (EFSA). This introductory review aims to give a comparative account of the risk assessment steps used in human health and animal health risk assessments for chemicals in the food chain and provides a critical view of the data gaps and future perspectives for this cross-disciplinary field. - Highlights: ► Principles of human and animal health risk assessment. ► Data gaps for each step of animal health risk assessment. ► Implications of animal risk assessment on human risk assessment. ► Future perspectives on chemical risk assessment.

  18. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  19. EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Vanessa Martins

    2015-02-01

    Full Text Available The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol. The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

  20. Effects of scalp dermatitis on chemical property of hair keratin

    Science.gov (United States)

    Kim, Kyung Sook; Shin, Min Kyung; Park, Hun-Kuk

    2013-05-01

    The effects of scalp dermatitis (seborrheic dermatitis (SD), psoriasis, and atopic dermatitis (AD)) on chemical properties of hair keratin were investigated by Fourier transform infrared (FT-IR) spectroscopy. Hairs were collected from lesional regions affected by SD, psoriasis, and AD and non-lesional regions separately. The hairs with SD were taken from patients with ages of 16-80 years. The ages of patients with psoriasis ranged from 8 to 67 years, and all patients exhibited moderate disease. Hairs with AD were taken from the patients with ages of 24-45 years and the average SCORing atopic dermatitis (SCORAD) was 48.75. Hairs from 20 normal adults were collected as a control. The FT-IR absorbance bands were analyzed by the Gaussian model to obtain the center frequency, half width, height, and area of each band. The height and area of all bands in the spectra were normalized to the amide I centered at 1652 cm-1 to quantitatively analyze the chemical composition of keratin. The spectra of hair with scalp dermatitis were different with that of control, the amide A components centered at 3278 cm-1 were smaller than those of the control. The psoriasis hair showed a large difference in the IR absorbance band between lesional and non-lesional hairs indicating good agreement with the morphological changes. The hairs with diseases did not show differences in the content of cystine, which was centered at 1054 cm-1, from the control. The chemical properties of keratin were not significantly different between the hairs affected by SD, psoriasis, and AD. However, the changes induced by scalp dermatitis were different with weathering. Therefore, FT-IR analysis could be used to screen differences between the physiological and pathological conditions of scalp hair.

  1. Environmental and health hazard ranking and assessment of plastic polymers based on chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Lithner, Delilah, E-mail: delilah.lithner@gmail.com; Larsson, Ake; Dave, Goeran

    2011-08-15

    Plastics constitute a large material group with a global annual production that has doubled in 15 years (245 million tonnes in 2008). Plastics are present everywhere in society and the environment, especially the marine environment, where large amounts of plastic waste accumulate. The knowledge of human and environmental hazards and risks from chemicals associated with the diversity of plastic products is very limited. Most chemicals used for producing plastic polymers are derived from non-renewable crude oil, and several are hazardous. These may be released during the production, use and disposal of the plastic product. In this study the environmental and health hazards of chemicals used in 55 thermoplastic and thermosetting polymers were identified and compiled. A hazard ranking model was developed for the hazard classes and categories in the EU classification and labelling (CLP) regulation which is based on the UN Globally Harmonized System. The polymers were ranked based on monomer hazard classifications, and initial assessments were made. The polymers that ranked as most hazardous are made of monomers classified as mutagenic and/or carcinogenic (category 1A or 1B). These belong to the polymer families of polyurethanes, polyacrylonitriles, polyvinyl chloride, epoxy resins, and styrenic copolymers. All have a large global annual production (1-37 million tonnes). A considerable number of polymers (31 out of 55) are made of monomers that belong to the two worst of the ranking model's five hazard levels, i.e. levels IV-V. The polymers that are made of level IV monomers and have a large global annual production (1-5 million tonnes) are phenol formaldehyde resins, unsaturated polyesters, polycarbonate, polymethyl methacrylate, and urea-formaldehyde resins. This study has identified hazardous substances used in polymer production for which the risks should be evaluated for decisions on the need for risk reduction measures, substitution, or even phase out

  2. Effects of chemical contaminants on growth, age-structure, and reproduction of Mytilus edulis complex from Puget sound, Washington.

    Science.gov (United States)

    Kagley, Anna N; Kardong, Kyle E; Snider, Robert G; Casillas, Edmundo

    2014-07-01

    Bivalves are used as sentinel species to detect chemical contaminants in the marine environment, but biological effects on indigenous populations that result from chemical exposure are largely unknown. We assessed age-weight, length-weight relationships, age structure, and reproductive status (i.e. fecundity, egg size) of the blue mussel Mytilus edulis complex from six sites in central Puget Sound, Washington, and one site in the relatively pristine area of northern Puget Sound. Results of this study suggest that mussels from urban areas of Puget Sound exhibit a lower growth rate, altered population age-structure, and potential reproductive impairment as a result of exposure to chemical contaminants. These findings support the use of mussels as sentinel species to assess the biological effects of contaminants on invertebrate populations.

  3. Mechano-chemical effects in weakly charged porous media.

    Science.gov (United States)

    Zholkovskij, Emiliy K; Yaroshchuk, Andriy E; Koval'chuk, Volodymyr I; Bondarenko, Mykola P

    2015-08-01

    The paper is concerned with mechano-chemical effects, namely, osmosis and pressure-driven separation of ions that can be observed when a charged porous medium is placed between two electrolyte solutions. The study is focused on porous systems with low equilibrium interfacial potentials (about 30 mV or lower). At such low potentials, osmosis and pressure-driven separation of ions noticeably manifest themselves provided that the ions in the electrolyte solutions have different diffusion coefficients. The analysis is conducted by combining the irreversible thermodynamic approach and the linearized (in terms of the normalized equilibrium interfacial potential) version of the Standard Electrokinetic Model. Osmosis and the pressure-driven separation of ions are considered for an arbitrary mixed electrolyte solution and various porous space geometries. It is shown that the effects under consideration are proportional to a geometrical factor which, for all the considered geometries of porous space, can be expressed as a function of porosity and the Λ- parameter of porous medium normalized by the Debye length. For all the studied geometries, this function turns out to be weakly dependent on both the porosity and the geometry type. The latter allows for a rough evaluation of the geometrical factor from experimental data on electric conductivity and hydraulic permeability without previous knowledge of the porous space geometry. The obtained results are used to illustrate how the composition of electrolyte solution affects the mechano-chemical effects. For various examples of electrolyte solution compositions, the obtained results are capable of describing positive, negative and anomalous osmosis, positive and negative rejection of binary electrolytes, and pressure-driven separation of binary electrolyte mixtures.

  4. Modelling of structural effects on chemical reactions in turbulent flows

    Energy Technology Data Exchange (ETDEWEB)

    Gammelsaeter, H.R.

    1997-12-31

    Turbulence-chemistry interactions are analysed using algebraic moment closure for the chemical reaction term. The coupling between turbulence and chemical length and time scales generate a complex interaction process. This interaction process is called structural effects in this work. The structural effects are shown to take place on all scales between the largest scale of turbulence and the scales of the molecular motions. The set of equations describing turbulent correlations involved in turbulent reacting flows are derived. Interactions are shown schematically using interaction charts. Algebraic equations for the turbulent correlations in the reaction rate are given using the interaction charts to include the most significant couplings. In the frame of fundamental combustion physics, the structural effects appearing on the small scales of turbulence are proposed modelled using a discrete spectrum of turbulent scales. The well-known problem of averaging the Arrhenius law, the specific reaction rate, is proposed solved using a presumed single variable probability density function and a sub scale model for the reaction volume. Although some uncertainties are expected, the principles are addressed. Fast chemistry modelling is shown to be consistent in the frame of algebraic moment closure when the turbulence-chemistry interaction is accounted for in the turbulent diffusion. The modelling proposed in this thesis is compared with experimental data for an laboratory methane flame and advanced probability density function modelling. The results show promising features. Finally it is shown a comparison with full scale measurements for an industrial burner. All features of the burner are captured with the model. 41 refs., 33 figs.

  5. Review of Wildfire Effects on Chemical Water Quality

    Energy Technology Data Exchange (ETDEWEB)

    Kelly Bitner; Bruce Gallaher; Ken Mullen

    2001-05-01

    The Cerro Grande Fire of May 2000 burned almost 43,000 acres of forested land within the Pajarito Plateau watershed in northern New Mexico. Runoff events after the fire were monitored and sampled by Los Alamos National Laboratory. Changes in the composition of runoff water were noted when compared to runoff water composition of the previous 20 years. In order to understand the chemical water quality changes noted in runoff water after the Cerro Grande Fire, a summary of the reported effects of fire on runoff water chemistry and on soils that contribute to runoff water chemistry was compiled. The focus of this report is chemical water quality, so it does not address changes in sediment transport or water quantity associated with fires. Within the general inorganic parameters, increases of dissolved calcium, magnesium, nitrogen, phosphorus, and potassium and pH in runoff water have been observed as a result of fire. However, the dissolved sodium, carbon, and sulfate have been observed to increase and decrease as a result of fire. Metals have been much less studied, but manganese, copper, zinc, and cesium-137 have been observed to increase as a result of fire.

  6. Polyoxometalates in Oxidative Delignification of Chemical Pulps: Effect on Lignin

    Directory of Open Access Journals (Sweden)

    Kolby Hirth

    2010-03-01

    Full Text Available Chemical pulps are produced by chemical delignification of lignocelluloses such as wood or annual non-woody plants. After pulping (e.g., kraft pulping, the remaining lignin is removed by bleaching to produce a high quality, bright paper. The goal of bleaching is to remove lignin from the pulp without a negative effect on the cellulose; for this reason, delignification should be performed in a highly selective manner. New environmentally-friendly alternatives to conventional chlorine-based bleaching technologies (e.g., oxygen, ozone, or peroxide bleaching have been suggested or implemented. In an attempt to find inorganic agents that mimic the action of highly selective lignin-degrading enzymes and that can be applicable in industrial conditions, the researchers have focused on polyoxometalates (POMs, used either as regenerable redox reagents (in anaerobic conditions or as catalysts (in aerobic conditions of oxidative delignification. The aim of this paper is to review the basic concepts of POM delignification in these two processes.

  7. Effect of chemical additives on flow characteristics of coal slurries

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Mosa; A.-H. M. Saleh; T.A. Taha; A.M. El-Molla [Al-Azhar University, Cairo (Egypt). Mining & Petroleum Engineering Department

    2008-07-01

    In the present paper, the effect of chemical additives or reagents on rheological characteristics of coal water slurry (CWS) was investigated. The power-law model was applied to determine the non-Newtonian properties of coal slurries. Three types of dispersants namely, sulphonic acid, sodium tripolyphosphate and sodium carbonate were studied and tested at different concentrations ranging from 0.5 to 1.5% by weight from total solids. Sodium salt of carboxymethyl cellulose (Na-CMC) and xanthan gum were tested as stabilizers at concentrations in the range of 0.05 to 0.25% by weight from total solids. It was found that apparent viscosity and flow properties of CWS are sensitive to the use of chemical additives (dispersants and stabilizers). Among studied dispersing agents, sulphonic acid recorded the best performance in modification and reducing CWS viscosity. The best dosage of all tested dispersants was found to be 0.75% by wt of solids. With regard to studied stabilizers, Na-CMC recorded better performance than xanthan gum. The best dosage of investigated stabilizers was found to be as 0.1 % by wt. from total solids. 13 refs., 9 figs., 1 tab.

  8. Modeling the effect of water activity and storage temperature on chemical stability of coffee brews.

    Science.gov (United States)

    Manzocco, Lara; Nicoli, Maria Cristina

    2007-08-08

    This work was addressed to study the chemical stability of coffee brew derivatives as a function of water activity (aw) and storage temperature. To this purpose, coffee brew was freeze-dried, equilibrated at increasing aw values, and stored for up to 10 months at different temperatures from -30 to 60 degrees C. The chemical stability of the samples was assessed by measuring H3O+ formation during storage. Independently of storage temperature, the rate of H3O+ formation was considerably low only when aw was reduced below 0.5 (94% w/w). Beyond this critical boundary, the rate increased, reaching a maximum value at ca. 0.8 aw (78% w/w). Further hydration up to the aw of the freshly prepared beverage significantly increased chemical stability. It was suggested that mechanisms other than lactones' hydrolysis, probably related to nonenzymatic browning pathways, could contribute to the observed increase in acidity during coffee staling. The temperature dependence of H3O+ formation was well-described by the Arrhenius equation in the entire aw range considered. However, aw affected the apparent activation energy and frequency factor. These effects were described by simple equations that were used to set up a modified Arrhenius equation. This model was validated by comparing experimental values, not used to generate the model, with those estimated by the model itself. The model allowed efficient prediction of the chemical stability of coffee derivatives on the basis of only the aw value and storage temperature.

  9. Effect of chemical composition of sheep’s milk on the chemical composition of Livno and Travnik cheese

    Directory of Open Access Journals (Sweden)

    Amina Hrković

    2011-06-01

    Full Text Available Bosnia and Herzegovina has a centuries-old tradition in the family dairy products, among which 2-3 types of cheeses dominate. Well known dairy products in BiH are indigenous Livno and Travnik cheese, a group of cheeses produced from thermally untreated raw sheep milk. The aim of this study was assessing the effects of certain parameters on the chemical composition of the milk composition of indigenous cheeses - Livno and Travnik. Two manufacturers within two different locations (Livno and Travnik during summer grazing of sheep, were selected for this research. The study included 117sheep (Livno 57 sheep, Travnik 60 sheep. The cheese milk was used for determination of fat, protein and lactose content. Six samples were taken from obtained cheeses: 3 samples of Livno and 3samples of Travnik cheese, which means one for each sampling period. In cheese dry matter content, water, fat, fat in dry matter and acidity (pH were determined, and then correlation between the constituents of milk and cheese ingredients content was set. The most common causes of such phenomenon is non-standard production, storage and ripening. On Travnik area, the content of fat and milk protein varied according to sampling period, which can be attributed to the already mentioned diet and stage of lactation. At the same time the protein content decreased mainly by the end of lactating period. Lactose content has proven to be the most stable parameter of milk. In both investigated cheese samples slightly higher water content was found compared to normal values for these two local cheese, while the proportion of fat and dry matter varied within the sampling period. Variation of certain parameters of the chemical composition of investigated samples of Livno and Travnik cheese, as well as their correlation with parameters of milk is primarily a consequence of changing the chemical composition of milk as the basic raw materials and/or significant variations in technology that could

  10. Epigenetic Effects of Environmental Chemicals Bisphenol A and Phthalates

    Directory of Open Access Journals (Sweden)

    Steven Shoei-Lung Li

    2012-08-01

    Full Text Available The epigenetic effects on DNA methylation, histone modification, and expression of non-coding RNAs (including microRNAs of environmental chemicals such as bisphenol A (BPA and phthalates have expanded our understanding of the etiology of human complex diseases such as cancers and diabetes. Multiple lines of evidence from in vitro and in vivo models have established that epigenetic modifications caused by in utero exposure to environmental toxicants can induce alterations in gene expression that may persist throughout life. Epigenetics is an important mechanism in the ability of environmental chemicals to influence health and disease, and BPA and phthalates are epigenetically toxic. The epigenetic effect of BPA was clearly demonstrated in viable yellow mice by decreasing CpG methylation upstream of the Agouti gene, and the hypomethylating effect of BPA was prevented by maternal dietary supplementation with a methyl donor like folic acid or the phytoestrogen genistein. Histone H3 was found to be trimethylated at lysine 27 by BPA effect on EZH2 in a human breast cancer cell line and mice. BPA exposure of human placental cell lines has been shown to alter microRNA expression levels, and specifically, miR-146a was strongly induced by BPA treatment. In human breast cancer MCF7 cells, treatment with the phthalate BBP led to demethylation of estrogen receptor (ESR1 promoter-associated CpG islands, indicating that altered ESR1 mRNA expression by BBP is due to aberrant DNA methylation. Maternal exposure to phthalate DEHP was also shown to increase DNA methylation and expression levels of DNA methyltransferases in mouse testis. Further, some epigenetic effects of BPA and phthalates in female rats were found to be transgenerational. Finally, the available new technologies for global analysis of epigenetic alterations will provide insight into the extent and patterns of alterations between human normal and diseased tissues.

  11. Evaluating effects of sewage sludge and household compost on soil physical, chemical and microbiological properties

    DEFF Research Database (Denmark)

    Debosz, K.; Petersen, S.O.; Kure, L.K.

    2002-01-01

    , effects of waste amendment were positive, but moderate compared to the dynamics observed in unamended soil, and mainly occurred in the first several weeks after amendment. The temporal dynamics of inorganic N, FDA hydrolysis activity, biomass C and PLFA composition appeared to be faster under...... amendment on the fraction of soil in wet-stable aggregates, or on the microbiological properties tested, which supported the observation from the incubation study that effects of organic wastes were transient. (C) 2002 Elsevier Science B.V. All rights reserved.......Recycling of organic wastes within agriculture may help maintain soil fertility via effects on physical, chemical and biological properties. Efficient use, however, requires an individual assessment of waste products, and effects should be compared with natural variations due to climate and soil...

  12. Exposure assessment in studies on health effects of traffic exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Setaelae, S. [Association for the Pulmonary Disabled, Helsinki (Finland); Jaakkola, J.J.K. [Helsinki Univ. (Finland). Dept. of Public Health

    1995-12-31

    A main source of outdoor air pollution is road traffic, which produces a complex mixture of nitrogen oxides, carbon monoxide, volatile hydrocarbons, airborne particles and some other compounds. Traffic exhaust affects also the concentrations of ozone and other photo chemical oxidants. In earlier studies those components have had remarkable health effects. Several studies on occupational exposure to automobile exhaust have been published and several studies have been observed an association between both outdoor and indoor pollutant levels and health outcomes. However, there are only a few epidemiological studies in which traffic exhaust, a complex mixture, has been studied in its entirety. During recent years, interesting epidemiological studies of the health effects of this complex mixture have been published. Human exposure assessment for traffic exhaust can be categorized according to the environment of exposure (indoors, outdoors, in-traffic) or to the method of exposure assessment (direct or indirect methods). In this presentation the methods are further categorized into (1) traffic activity, (2) air concentration measurements, and (3) dispersion models, in order to better understand the advantages and disadvantages of different approaches. The objective of this presentation is to make a critical review of exposure assessments in the epidemiological studies on health effects of traffic exhaust. (author)

  13. Dehydration: physiology, assessment, and performance effects.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W

    2014-01-01

    This article provides a comprehensive review of dehydration assessment and presents a unique evaluation of the dehydration and performance literature. The importance of osmolality and volume are emphasized when discussing the physiology, assessment, and performance effects of dehydration. The underappreciated physiologic distinction between a loss of hypo-osmotic body water (intracellular dehydration) and an iso-osmotic loss of body water (extracellular dehydration) is presented and argued as the single most essential aspect of dehydration assessment. The importance of diagnostic and biological variation analyses to dehydration assessment methods is reviewed and their use in gauging the true potential of any dehydration assessment method highlighted. The necessity for establishing proper baselines is discussed, as is the magnitude of dehydration required to elicit reliable and detectable osmotic or volume-mediated compensatory physiologic responses. The discussion of physiologic responses further helps inform and explain our analysis of the literature suggesting a ≥ 2% dehydration threshold for impaired endurance exercise performance mediated by volume loss. In contrast, no clear threshold or plausible mechanism(s) support the marginal, but potentially important, impairment in strength, and power observed with dehydration. Similarly, the potential for dehydration to impair cognition appears small and related primarily to distraction or discomfort. The impact of dehydration on any particular sport skill or task is therefore likely dependent upon the makeup of the task itself (e.g., endurance, strength, cognitive, and motor skill).

  14. Environmental and health hazard ranking and assessment of plastic polymers based on chemical composition.

    Science.gov (United States)

    Lithner, Delilah; Larsson, Ake; Dave, Göran

    2011-08-15

    Plastics constitute a large material group with a global annual production that has doubled in 15 years (245 million tonnes in 2008). Plastics are present everywhere in society and the environment, especially the marine environment, where large amounts of plastic waste accumulate. The knowledge of human and environmental hazards and risks from chemicals associated with the diversity of plastic products is very limited. Most chemicals used for producing plastic polymers are derived from non-renewable crude oil, and several are hazardous. These may be released during the production, use and disposal of the plastic product. In this study the environmental and health hazards of chemicals used in 55 thermoplastic and thermosetting polymers were identified and compiled. A hazard ranking model was developed for the hazard classes and categories in the EU classification and labelling (CLP) regulation which is based on the UN Globally Harmonized System. The polymers were ranked based on monomer hazard classifications, and initial assessments were made. The polymers that ranked as most hazardous are made of monomers classified as mutagenic and/or carcinogenic (category 1A or 1B). These belong to the polymer families of polyurethanes, polyacrylonitriles, polyvinyl chloride, epoxy resins, and styrenic copolymers. All have a large global annual production (1-37 million tonnes). A considerable number of polymers (31 out of 55) are made of monomers that belong to the two worst of the ranking model's five hazard levels, i.e. levels IV-V. The polymers that are made of level IV monomers and have a large global annual production (1-5 million tonnes) are phenol formaldehyde resins, unsaturated polyesters, polycarbonate, polymethyl methacrylate, and urea-formaldehyde resins. This study has identified hazardous substances used in polymer production for which the risks should be evaluated for decisions on the need for risk reduction measures, substitution, or even phase out.

  15. Approaches to assessing the risk of chemical contamination of Urban Soils

    Science.gov (United States)

    Makarov, O. A.; Makarov, A. A.

    2016-09-01

    The existing approaches to studying the risk of chemical contamination of soils are analyzed. It is noted that the actual and critical loads of contaminants on the soil cover are often compared for estimating these risks. The insufficient use of economic tools and methods for assessing the risk of soil contamination is emphasized. The sanitary-hygienic standards are found out to be exceeded for lead, zinc, cadmium and copper content in soils in six localities, each of 6250 m2 in the area, situated in the industrial and transport zones of Podol'sk and Moscow. The values of actual and maximal permissible damage exerted by the heavy-metal contamination to the studied soils are calculated. The probable damage R and the degree of probable damage implementation (DPDI) are used as the indices of soil contamination risk.

  16. Assessment of existing H2/O2 chemical reaction mechanisms at reheat gas turbine conditions

    CERN Document Server

    Weydahl, Torleif; Seljeskog, Morten; Haugen, Nils Erland L

    2011-01-01

    This paper provides detailed comparisons of chemical reaction mechanisms of H2 applicable at high preheat temperatures and pressures relevant to gas turbine and particularly Alstom's reheat gas turbine conditions. It is shown that the available reaction mechanisms exhibit large differences in several important elementary reaction coefficients. The reaction mechanisms are assessed by comparing ignition delay and laminar flame speed results obtained from CHEMKIN with available data, however, the amount of data at these conditions is scarce and a recommended candidate among the mechanisms can presently not be selected. Generally, the results with the GRI-Mech and Leeds mechanisms deviate from the Davis, Li, O'Conaire, Konnov and San Diego mechanisms, but there are also significant deviations between the latter five mechanisms that altogether are better adapted to hydrogen. The differences in ignition delay times between the dedicated hydrogen mechanisms (O'Conaire, Li and Konnov) range from approximately a maxim...

  17. Epidemiologic approaches to assessing human cancer risk from consuming aquatic food resources from chemically contaminated water

    Energy Technology Data Exchange (ETDEWEB)

    Ozonoff, D. (Boston Univ. School of Public Health, MA (United States)); Longnecker, M.P. (UCLA School of Public Health, Los Angeles, CA (United States))

    1991-01-01

    Epidemiologic approaches to assessing human cancer risk from contaminated waters must confront the problems of long latency and rarity of the end point (cancer). The latency problem makes determination of diet history more difficult, while the low frequency of cancer as an end point reduces the statistical power of the study. These factors are discussed in relation to the study designs most commonly employed in epidemiology. It is suggested that the use of biomarkers for persistent chemicals may be useful to mitigate the difficulty of determining exposure, while the use of more prevalent and timely end points, such as carcinogen-DNA adducts or oncogene proteins, may make the latency and rarity problems more tractable.

  18. Organizational and activational effects of estrogenic endocrine disrupting chemicals

    Directory of Open Access Journals (Sweden)

    Silbergeld Ellen K.

    2002-01-01

    Full Text Available Endocrine disruption is a hypothesis of common mode of action that may define a set of structurally varied chemicals, both natural and synthetic. Their common mode of action may suggest that they produce or contribute to similar toxic effects, although this has been difficult to demonstrate. Insights from developmental biology suggest that development of hormone sensitive systems, such as the brain and the genitourinary tract, may be particularly sensitive to EDCs. Because these systems are both organized and later activated by hormones, the brain and vagina may be valuable model systems to study the toxicity of EDCs in females and to elucidate mechanisms whereby early exposures appear to affect long term function.

  19. Irradiation Effects on the Chemical Quality of Guavas

    Directory of Open Access Journals (Sweden)

    Rosario

    2013-02-01

    Full Text Available The aim of this research is to evaluate the effect of radiation treatment on the chemical changes of main components of guavas (Psidium guajava, var. media china. The quality of guavas irradiated by Co-60 gamma rays at 150, 200, and 300 Gray as Gy/min were evaluated during storage at room and low temperature. Results indicated that the differences observed are principally associated with maturity stages, temperature, and changes attributed to physiological and metabolic processes. Radiation treatment produced reductions in ascorbic acid and &beta-carotene. The results suggest that fruit in storage can recover from stress produced by treatment. No other significant changes were observed in any other parameters including sugars, pectin, and citric acid.

  20. Cytocompatibility assessment of chemical surface treatments for phosphate glass to improve adhesion between glass and polyester.

    Science.gov (United States)

    S Hasan, M; Ahmed, I; Parsons, A J; Walker, G S; Scotchford, C A

    2013-11-01

    Fully resorbable phosphate glass fiber reinforced polymer composites have shown real potential for replacing some of the existing metallic bone fracture fixation devices. However, some of these composites have not provided suitable mechanical strength profiles over the required healing period for bone. Typically, it has been seen that these composites can lose up to 50% or more of their strength within the first week of degradation. Functionalizing the glass surface to promote polymer adhesion or to introduce hydrophobicity at the glass surface could potentially introduce control over the mechanical properties of the composite and their retention. In this study eight chemical agents namely, Glycerol 2-phosphate disodium salt; 3-phosphonopropionic acid; 3-aminopropyltriethoxy silane; etidronic acid; hexamethylene diisocyanate; sorbitol/sodium ended PLA oligomers and amino phosphonic acid, were selected to functionalise the bulk phosphate glass surface. Selected chemical agents had one functional group (-OH or O C N) to react with the glass and another functionality (either -OH, NH2, or Na) to react with the polymer matrix and/or produce hydrophobicity at the fiber surface. Bulk phosphate glass surface-treated with the above agents were assessed for the cytotoxicity of degradation products cell-material interaction in short- and long-term direct cytocompatibility studies. Results obtained from these cytocompatibility studies (using human osteosarcoma (MG63) and primary human osteoblast cell lines) revealed no cytotoxicity from the degradation products and a response comparable to controls in terms of cell functions (attachment, viability, metabolic activity, proliferation, and differentiation) and morphology.

  1. Comprehensive assessment of germline chemical toxicity using the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Parodi, Daniela A; Damoiseaux, Robert; Allard, Patrick

    2015-02-22

    Identifying the reproductive toxicity of the thousands of chemicals present in our environment has been one of the most tantalizing challenges in the field of environmental health. This is due in part to the paucity of model systems that can (1) accurately recapitulate keys features of reproductive processes and (2) do so in a medium- to high-throughput fashion, without the need for a high number of vertebrate animals. We describe here an assay in the nematode C. elegans that allows the rapid identification of germline toxicants by monitoring the induction of aneuploid embryos. By making use of a GFP reporter line, errors in chromosome segregation resulting from germline disruption are easily visualized and quantified by automated fluorescence microscopy. Thus the screening of a particular set of compounds for its toxicity can be performed in a 96- to 384-well plate format in a matter of days. Secondary analysis of positive hits can be performed to determine whether the chromosome abnormalities originated from meiotic disruption or from early embryonic chromosome segregation errors. Altogether, this assay represents a fast first-pass strategy for the rapid assessment of germline dysfunction following chemical exposure.

  2. Further assessment of the chemical modelling of iodine in IMPAIR 3 code using ACE/RTF data

    Energy Technology Data Exchange (ETDEWEB)

    Cripps, R.C.; Guentay, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-01

    This paper introduces the assessment of the computer code IMPAIR 3 (Iodine Matter Partitioning And Iodine Release) which simulates physical and chemical iodine processes in a LWR containment with one or more compartments under conditions relevant to a severe accident in a nuclear reactor. The first version was published in 1992 to replace both the multi-compartment code IMPAIR 2/M and the single-compartment code IMPAIR 2.2. IMPAIR 2.2 was restricted to a single pH value specified before programme execution and precluded any variation of pH or calculation of H{sup +} changes during program execution. This restriction is removed in IMPAIR 3. Results of the IMPAIR 2.2 assessment using ACE/RTF Test 2 and the acidic phase of Test 3 B data were presented at the 3rd CSNI Workshop. The purpose of the current assessment is to verify the IMPAIR 3 capability to follow the whole test duration with changing boundary conditions. Besides revisiting ACE/RTF Test 3B, Test 4 data were also used for the current assessment. A limited data analysis was conducted using the outcome of the current ACEX iodine work to understand the iodine behaviour observed during these tests. This paper presents comparisons of the predicted results with the test data. The code capabilities are demonstrated to focus on still unresolved modelling problems. The unclear behaviour observed in the gaseous molecular iodine behaviour and its inconclusive effect on the calculated behaviour in the acidic phase of the Test 4 and importance of the catalytic effect of stainless steel are also indicated. (author) 18 figs., 1 tab., 11 refs.

  3. Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) TRACI version 2.1 User’s Guide

    Science.gov (United States)

    TRACI 2.1 (the Tool for the Reduction and Assessment of Chemical and other environmental Impacts) has been developed for sustainability metrics, life cycle impact assessment, industrial ecology, and process design impact assessment for developing increasingly sustainable products...

  4. Effect of slurry chemicals on chemical-mechanical planarization of copper

    Science.gov (United States)

    Hong, Youngki

    An important component of the slurries used in chemical mechanical planarization (CMP) is an appropriately chosen corrosion/dissolution inhibitor, which facilitates selective material removal from protrusions while protecting recessed regions of the surface. The present work demonstrates the utility of two environmentally benign anionic surfactants, sodium dodecyl sulfate (SDS) and ammonium dodecyl sulfate (ADS) as dissolution inhibitors. Using these surfactants in a standard slurry (1 wt% glycine with 5 wt% H2O 2 at pH = 4.0) typically used for Cu CMP, and combining measurements of open circuit potentials and contact angles with those of Cu removal rates, we show that both SDS and ADS suppress chemical dissolution and polish rates of Cu. The dissolution inhibition efficiencies of ADS and SDS measured in these experiments are found to be superior to those of benzotriazole (BTA), a traditional inhibiting agent used for copper CMP. It has been demonstrated that ADS can also be utilized as an inhibiting agent for the application in electrochemical-mechanical planarization (ECMP) of copper. Using an acidic electrolyte of glycine and H2O 2, and small Cu discs, we show that the corrosion inhibition efficiency of ADS is superior to that of benzotriazole even in ECMP application. The relation between PE of Cu patterns and complexing agents has been investigated by measuring removal rates and surface topographies from patterns created on blanket Cu films. It has been observed that PE is dependent on the step height and drops significantly beyond a threshold step height that is in the range of 1000 A. Since the same type of polishing pad (IC 1400) was used in all the experiments, it might be the complexing agent that determines this characteristic PE threshold. Also, the huge increase in Cu dissolution rate for the citric acid system with increasing temperature appears to be responsible for the low PE values measured for this system. The synergetic effect of mixtures of ADS

  5. Effects Based Assessment Support System (EBASS)

    Science.gov (United States)

    2006-05-01

    Group, usually attended by the Director of the CJFT Staff, BG Byron Bagby or by the Commanding General, LTG John Vines . Each week, the presiding general...Army works hard to improve the reliability and timeliness of Battle Damage Assessment (BDA) to ensure the effectiveness of their operations to... Frost , B. (2000). Measuring Performance: Using the New Metrics to Deploy Strategy and Improve Performance. Dallas, TX: Measurement International

  6. Evaluating the effectiveness of impact assessment instruments

    DEFF Research Database (Denmark)

    Cashmore, Matthew; Richardson, Tim; Hilding-Ryedvik, Tuija

    2010-01-01

    in Western countries, demand has increased for evidence that these instruments are effective (however defined). Resurgent interest in evaluation has not, however, been accompanied by the conceptual developments required to redress longstanding theoretical problems associated with such activities. In order......The central role of impact assessment instruments globally in policy integration initiatives has been cemented in recent years. Associated with this trend, but also reflecting political emphasis on greater accountability in certain policy sectors and a renewed focus on economic competitiveness...

  7. The chemical substances and the neurotoxic effect on workers

    Directory of Open Access Journals (Sweden)

    Rosa Morales

    2013-12-01

    Full Text Available (Received: 2013/10/02 - Accepted: 2013/12/13Tens of thousands of workers are exposed to pollution by the neurotoxicity found in their different workplaces, small businesses, handcrafting industries and even at home. The problem gets worst due to the lack of information on the risks posed by these substances and the safety controls to be taken during its use, on the other hand, the overconfidence that exists about the abstraction of this danger when it comes to the exposure to small doses of toxicity by ignoring the cumulative effects of these substances every time they enter the body. In Ecuador, nowadays there are few studies that distinguish this exposure to these substances, and none on the incidence of the neurotoxic syndrome, considering it an important field to research. Workers who are exposed to chemical toxic substances are now associated to adverse human health effects, due to its aggression and because of the worker´s safety before breaking health directly. They enter the body by the respiratory, dermal or digestive system, and show a great affinity with the body grease so that it accumulates and affects the different organs, tissues, the central nervous system, the bone marrow and liver. Immediate acute and chronic long-term effects were detected due to the intensity and duration of the exposure. Some symptoms include drowsiness, loss of appetite, headache, dizziness, depression, anxiety, nervousness, fatigue, irritability, memory problems, mental sluggishness, apathy, seizures, motor skills incoordination, genetic alterations, among others.

  8. Assessment of physico-chemical qualities and heavy metal concentrations of Umgeni and Umdloti Rivers in Durban, South Africa.

    Science.gov (United States)

    Olaniran, Ademola O; Naicker, Kovashnee; Pillay, Balakrishna

    2014-04-01

    We assessed the effects of seasonal dynamics on the physico-chemical qualities and heavy metals concentrations of the Umgeni and Umdloti Rivers in Durban, South Africa. Water samples were taken from nine different sampling points and analysed for the following parameters; temperature, pH, turbidity, electrical conductivity (EC), biological oxygen demand (BOD5), chemical oxygen demand (COD), phosphate (PO4(2-)), nitrate (NO3(2-)), ammonium (NH4(+)), sulphate (SO4(2-)), lead (Pb(2+)), mercury (Hg(2+)), cadmium (Cd(2+)), aluminium (Al(3+)), and copper (Cu(2+)) using standard methods. The data showed variations it terms of the seasonal fluctuations and sampling regime as follows: temperature 12-26.5 °C; pH 5.96-8.45; turbidity 0.53-18.8 NTU; EC 15.8-5180 mS m(-1); BOD5 0.60-7.32 mg L(-1); COD 10.5-72.9 mg L(-1); PO4 (2-) South African Guidelines and World Health Organization tolerance limits for freshwater quality. We conclude that these water bodies are potentially hazardous to public health and this highlights the need for implementation of improved management strategies of these river catchments for continued sustainability.

  9. Assessing the Higher National Diploma Chemical Engineering Programme in Ghana: Students' Perspective

    Science.gov (United States)

    Boateng, Cyril D.; Bensah, Edem Cudjoe; Ahiekpor, Julius C.

    2012-01-01

    Chemical engineers have played key roles in the growth of the chemical and allied industries in Ghana but indigenous industries that have traditionally been the domain of the informal sector need to be migrated to the formal sector through the entrepreneurship and innovation of chemical engineers. The Higher National Diploma Chemical Engineering…

  10. Quality assessment of cortex cinnamomi by HPLC chemical fingerprint, principle component analysis and cluster analysis.

    Science.gov (United States)

    Yang, Jie; Chen, Li-Hong; Zhang, Qin; Lai, Mao-Xiang; Wang, Qiang

    2007-06-01

    HPLC fingerprint analysis, principle component analysis (PCA), and cluster analysis were introduced for quality assessment of Cortex cinnamomi (CC). The fingerprint of CC was developed and validated by analyzing 30 samples of CC from different species and geographic locations. Seventeen chromatographic peaks were selected as characteristic peaks and their relative peak areas (RPA) were calculated for quantitative expression of the HPLC fingerprints. The correlation coefficients of similarity in chromatograms were higher than 0.95 for the same species while much lower than 0.6 for different species. Besides, two principal components (PCs) have been extracted by PCA. PC1 separated Cinnamomum cassia from other species, capturing 56.75% of variance while PC2 contributed for their further separation, capturing 19.08% variance. The scores of the samples showed that the samples could be clustered reasonably into different groups corresponding to different species and different regions. The scores and loading plots together revealed different chemical properties of each group clearly. The cluster analysis confirmed the results of PCA analysis. Therefore, HPLC fingerprint in combination with chemometric techniques provide a very flexible and reliable method for quality assessment of traditional Chinese medicines.

  11. Preliminary Assessment of Mercury Atmosphere-Surface Exchange Parameterizations for Incorporation into Chemical Transport Models

    Science.gov (United States)

    Khan, T.; Agnan, Y.; Obrist, D.; Selin, N. E.; Urban, N. R.; Wu, S.; Perlinger, J. A.

    2015-12-01

    Inadequate representation of process-based mechanisms of exchange behavior of elemental mercury (Hg0) and decoupled treatment of deposition and emission are two major limitations of parameterizations of atmosphere-surface exchange flux commonly incorporated into chemical transport models (CTMs). Of nineteen CTMs for Hg0 exchange we reviewed (ten global, nine regional), eight global and seven regional models have decoupled treatment of Hg0 deposition and emission, two global models include no parameterization to account for emission, and the remaining two regional models include coupled deposition and emission parameterizations (i.e., net atmosphere-surface exchange). The performance of atmosphere-surface exchange parameterizations in CTMs depends on parameterization uncertainty (in terms of both accuracy and precision) and feasibility of implementation. We provide a comparison of the performance of three available parameterizations of net atmosphere-surface exchange. To evaluate parameterization accuracy, we compare predicted exchange fluxes to field measurements conducted over a variety of surfaces compiled in a recently developed global database of terrestrial Hg0 surface-atmosphere exchange flux measurements. To assess precision, we estimate the sensitivity of predicted fluxes to the imprecision in parameter input values, and compare this sensitivity to that derived from analysis of the global Hg0 flux database. Feasibility of implementation is evaluated according to the availability of input parameters, computational requirements, and the adequacy of uncertainty representation. Based on this assessment, we provide suggestions for improved treatment of Hg0 net exchange processes in CTMs.

  12. Using chemical biology to assess and modulate mitochondria: progress and challenges

    Science.gov (United States)

    Murphy, Michael P.

    2017-01-01

    Our understanding of the role of mitochondria in biomedical sciences has expanded considerably over the past decade. In addition to their well-known metabolic roles, mitochondrial are also central to signalling for various processes through the generation of signals such as ROS and metabolites that affect cellular homeostasis, as well as other processes such as cell death and inflammation. Thus, mitochondrial function and dysfunction are central to the health and fate of the cell. Consequently, there is considerable interest in better understanding and assessing the many roles of mitochondria. Furthermore, there is also a growing realization that mitochondrial are a promising drug target in a wide range of pathologies. The application of interdisciplinary approaches at the interface between chemistry and biology are opening up new opportunities to understand mitochondrial function and in assessing the role of the organelle in biology. This work and the experience thus gained are leading to the development of new classes of therapies. Here, we overview the progress that has been made to date on exploring the chemical biology of the organelle and then focus on future challenges and opportunities that face this rapidly developing field. PMID:28382206

  13. Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET) bottles: A source of controversy reviewed.

    Science.gov (United States)

    Bach, Cristina; Dauchy, Xavier; Chagnon, Marie-Christine; Etienne, Serge

    2012-03-01

    A declaration of conformity according to European regulation No. 10/2011 is required to ensure the safety of plastic materials in contact with foodstuffs. This regulation established a positive list of substances that are authorized for use in plastic materials. Some compounds are subject to restrictions and/or specifications according to their toxicological data. Despite this, the analysis of PET reveals some non-intentionally added substances (NIAS) produced by authorized initial reactants and additives. Genotoxic and estrogenic activities in PET-bottled water have been reported. Chemical mixtures in bottled water have been suggested as the source of these toxicological effects. Furthermore, sample preparation techniques, such as solid-phase extraction (SPE), to extract estrogen-like compounds in bottled water are controversial. It has been suggested that inappropriate extraction methods and sample treatment may result in false-negative or positive responses when testing water extracts in bioassays. There is therefore a need to combine chemical analysis with bioassays to carry out hazard assessments. Formaldehyde, acetaldehyde and antimony are clearly related to migration from PET into water. However, several studies have shown other theoretically unexpected substances in bottled water. The origin of these compounds has not been clearly established (PET container, cap-sealing resins, background contamination, water processing steps, NIAS, recycled PET, etc.). Here, we surveyed toxicological studies on PET-bottled water and chemical compounds that may be present therein. Our literature review shows that contradictory results for PET-bottled water have been reported, and differences can be explained by the wide variety of analytical methods, bioassays and exposure conditions employed.

  14. Review of laboratory-based terrestrial bioaccumulation assessment approaches for organic chemicals: Current status and future possibilities.

    Science.gov (United States)

    Hoke, Robert; Huggett, Duane; Brasfield, Sandra; Brown, Becky; Embry, Michelle; Fairbrother, Anne; Kivi, Michelle; Paumen, Miriam Leon; Prosser, Ryan; Salvito, Dan; Scroggins, Rick

    2016-01-01

    In the last decade, interest has been renewed in approaches for the assessment of the bioaccumulation potential of chemicals, principally driven by the need to evaluate large numbers of chemicals as part of new chemical legislation, while reducing vertebrate test organism use called for in animal welfare legislation. This renewed interest has inspired research activities and advances in bioaccumulation science for neutral organic chemicals in aquatic environments. In January 2013, ILSI Health and Environmental Sciences Institute convened experts to identify the state of the science and existing shortcomings in terrestrial bioaccumulation assessment of neutral organic chemicals. Potential modifications to existing laboratory methods were identified, including areas in which new laboratory approaches or test methods could be developed to address terrestrial bioaccumulation. The utility of "non-ecotoxicity" data (e.g., mammalian laboratory data) was also discussed. The highlights of the workshop discussions are presented along with potential modifications in laboratory approaches and new test guidelines that could be used for assessing the bioaccumulation of chemicals in terrestrial organisms.

  15. Levels and risk assessment of chemical contaminants in byproducts for animal feed in Denmark.

    Science.gov (United States)

    Mortensen, Alicja; Granby, Kit; Eriksen, Folmer D; Cederberg, Tommy Licht; Friis-Wandall, Søren; Simonsen, Yvonne; Broesbøl-Jensen, Birgitte; Bonnichsen, Rikke

    2014-01-01

    With aim to provide information on chemical contaminants in byproducts in animal feed, the data from an official control by the Danish Plant Directorate during 1998-2009, were reviewed and several samples of citrus pulp and dried distillers grains with solubles (DDGS) were additionally collected for analysis and risk assessment. The levels of contaminants in the samples from the official control were below maximum limits from EU regulations with only a few exceptions in the following groups; dioxins and dioxin-like polychlorobiphenyls (PCBs) in fish-containing byproducts and dioxins in vegetable and animal fat, hydrogen cyanide in linseed, and cadmium in sunflowers. The levels of pesticides and mycotoxins in the additionally collected samples were below maximum limits. Enniatin B (ENN B) was present in all DDGS samples. The hypothetical cases of carry-over of contamination from these byproducts were designed assuming total absorption and accumulation of the ingested contaminant in meat and milk and high exposure (a byproduct formed 15-20% of the feed ration depending on the species). The risk assessment was refined based on literature data on metabolism in relevant animal species. Risk assessment of contaminants in byproducts is generally based on a worst-case approach, as data on carry-over of a contaminant are sparse. This may lead to erroneous estimation of health hazards. The presence of ENN B in all samples of DDGS indicates that potential impact of this emerging mycotoxin on feed and food safety deserves attention. A challenge for the future is to fill up gaps in toxicological databases and improve models for carry-over of contaminants.

  16. Chemicals and lemon essential oil effect on Alicyclobacillus acidoterrestris viability.

    Science.gov (United States)

    Maldonado, Maria Cristina; Aban, Marina Paola; Navarro, Antonio Roberto

    2013-12-01

    Alicyclobacillus acidoterrestris is considered to be one of the important target microorganisms in the quality control of acidic canned foods. There is an urgent need to develop a suitable method for inhibiting or controlling the germination and outgrowth of A.acidoterrestris in acidic drinks. The aim of this work was to evaluate the chemicals used in the lemon industry (sodium benzoate, potassium sorbate), and lemon essential oil as a natural compound, against a strain of A.acidoterrestris in MEB medium and in lemon juice concentrate. The results pointed out that sodium benzoate (500-1000-2000 ppm) and lemon essential oil (0.08-0.12-0.16%) completely inhibited the germination of A. acidoterrestris spores in MEB medium and LJC for 11 days. Potassium sorbate (600-1200 ppm) was more effective to inhibit the growth of the microbial target in lemon juice than in MEB medium. The effect of sodium benzoate, potassium sorbate and essential oil was sporostatic in MEB and LJC as they did not affect spore viability.

  17. Chemicals and lemon essential oil effect on Alicyclobacillus acidoterrestris viability

    Directory of Open Access Journals (Sweden)

    Maria Cristina Maldonado

    2013-12-01

    Full Text Available Alicyclobacillus acidoterrestris is considered to be one of the important target microorganisms in the quality control of acidic canned foods. There is an urgent need to develop a suitable method for inhibiting or controlling the germination and outgrowth of A.acidoterrestris in acidic drinks. The aim of this work was to evaluate the chemicals used in the lemon industry (sodium benzoate, potassium sorbate, and lemon essential oil as a natural compound, against a strain of A.acidoterrestris in MEB medium and in lemon juice concentrate. The results pointed out that sodium benzoate (500-1000-2000 ppm and lemon essential oil (0.08- 0.12- 0.16% completely inhibited the germination of A. acidoterrestris spores in MEB medium and LJC for 11 days. Potassium sorbate (600-1200 ppm was more effective to inhibit the growth of the microbial target in lemon juice than in MEB medium. The effect of sodium benzoate, potassium sorbate and essential oil was sporostatic in MEB and LJC as they did not affect spore viability.

  18. Deuterium isotope effects on 13C chemical shifts of 10-Hydroxybenzo[h]quinolines

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Kamounah, Fadhil S.; Gryko, Daniel T.

    2013-01-01

    Deuterium isotope effects on 13C-NMR chemical shifts are investigated in a series of 10-hydroxybenzo[h]quinolines (HBQ’s) The OH proton is deuteriated. The isotope effects on 13C chemical shifts in these hydrogen bonded systems are rather unusual. The formal four-bond effects are found to be nega......Deuterium isotope effects on 13C-NMR chemical shifts are investigated in a series of 10-hydroxybenzo[h]quinolines (HBQ’s) The OH proton is deuteriated. The isotope effects on 13C chemical shifts in these hydrogen bonded systems are rather unusual. The formal four-bond effects are found...

  19. Investigation of Electric Arc Furnace Chemical Reactions and stirring effect

    OpenAIRE

    Deng, Lei

    2012-01-01

    Chemical energy plays a big role in the process of modern Electric Arc Furnace (EAF). The objective of this study is to compare the results of chemical reaction enthalpies calculated by four different methods. In general, the “PERRY-NIST-JANAF method” is used to calculate the chemical energies. However, this method heavily depend on heat capacities of the substances which have to be deduced from  “Perry’s Chemical Engineers’ Handbook” and “NIST-JANAF Thermochemical Tables”, even the calculati...

  20. Essential Oils from Ugandan Aromatic Medicinal Plants: Chemical Composition and Growth Inhibitory Effects on Oral Pathogens.

    Science.gov (United States)

    Ocheng, Francis; Bwanga, Freddie; Joloba, Moses; Softrata, Abier; Azeem, Muhammad; Pütsep, Katrin; Borg-Karlson, Anna-Karin; Obua, Celestino; Gustafsson, Anders

    2015-01-01

    The study assessed the growth inhibitory effects of essential oils extracted from ten Ugandan medicinal plants (Bidens pilosa, Helichrysum odoratissimum, Vernonia amygdalina, Hoslundia opposita, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus, Teclea nobilis, Zanthoxylum chalybeum, and Lantana trifolia) used traditionally in the management of oral diseases against oral pathogens. Chemical compositions of the oils were explored by GC-MS. Inhibitory effects of the oils were assessed on periodontopathic Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and cariogenic Streptococcus mutans and Lactobacillus acidophilus using broth dilution methods at concentrations of 1%, 0.1%, and 0.01%. The most sensitive organism was A. actinomycetemcomitans. Its growth was markedly inhibited by six of the oils at all the concentrations tested. Essential oil from C. nardus exhibited the highest activity with complete growth inhibition of A. actinomycetemcomitans and P. gingivalis at all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Most of the oils exhibited limited effects on L. acidophilus. We conclude that essential oils from the studied plants show marked growth inhibitory effects on periodontopathic A. actinomycetemcomitans and P. gingivalis, moderate effects on cariogenic S. mutans, and the least effect on L. acidophilus. The present study constitutes a basis for further investigations and development of certain oils into alternative antiplaque agents.

  1. Essential Oils from Ugandan Aromatic Medicinal Plants: Chemical Composition and Growth Inhibitory Effects on Oral Pathogens

    Directory of Open Access Journals (Sweden)

    Francis Ocheng

    2015-01-01

    Full Text Available The study assessed the growth inhibitory effects of essential oils extracted from ten Ugandan medicinal plants (Bidens pilosa, Helichrysum odoratissimum, Vernonia amygdalina, Hoslundia opposita, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus, Teclea nobilis, Zanthoxylum chalybeum, and Lantana trifolia used traditionally in the management of oral diseases against oral pathogens. Chemical compositions of the oils were explored by GC-MS. Inhibitory effects of the oils were assessed on periodontopathic Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and cariogenic Streptococcus mutans and Lactobacillus acidophilus using broth dilution methods at concentrations of 1%, 0.1%, and 0.01%. The most sensitive organism was A. actinomycetemcomitans. Its growth was markedly inhibited by six of the oils at all the concentrations tested. Essential oil from C. nardus exhibited the highest activity with complete growth inhibition of A. actinomycetemcomitans and P. gingivalis at all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Most of the oils exhibited limited effects on L. acidophilus. We conclude that essential oils from the studied plants show marked growth inhibitory effects on periodontopathic A. actinomycetemcomitans and P. gingivalis, moderate effects on cariogenic S. mutans, and the least effect on L. acidophilus. The present study constitutes a basis for further investigations and development of certain oils into alternative antiplaque agents.

  2. Assessment of active pharmaceutical ingredient particle size in tablets by Raman chemical imaging validated using polystyrene microsphere size standards.

    Science.gov (United States)

    Kuriyama, Atsushi; Ozaki, Yukihiro

    2014-04-01

    Particle size is a critical parameter for controlling pharmaceutical quality. The aim of this study was to assess the size of the micrometer-scale active pharmaceutical ingredients (API) in tablets using Raman chemical imaging and to understand the effects of formulation on particle size. Model tablets containing National Institute of Standards and Technology traceable polystyrene microsphere size standards were developed to determine the binarization threshold value of Raman chemical images for API particle sizing in specific formulations and processes. Three sets of model tablets containing 5, 10, and 15 μm polystyrene microspheres, used to mimic API, were prepared using a commercial tablet formulation (Ebastel tablets, mean API particle size was about 5 μm). Raman mapping with a 50× objective (NA, 0.75) was applied to tablet cross-sections, and particle size of polystyrene microspheres was estimated from binary images using several binarization thresholds. Mean particle size for three sets of polystyrene microspheres showed good agreement between pre- and postformulation (the slope = 1.024, R = 1.000) at the specific threshold value ((mean + 0.5σ) of the polystyrene-specific peak intensity histogram), regardless of particle agglomeration, tablet surface roughness, and laser penetration depth. The binarization threshold value showed good applicability to Ebastel tablets, where the API-specific peak intensity histogram showed a pattern similar to that of polystyrene microspheres in model tablets. The model tablets enabled determination of an appropriate binarization threshold for assessing the mean particle size of micrometer-scale API in tablets by utilizing the unique physicochemical properties of polystyrene microspheres.

  3. Assessing the effectiveness of Denmark's waste tax

    DEFF Research Database (Denmark)

    Andersen, Mikael Skou

    1998-01-01

    By the mid-l980s, Denmark had a serious waste disposal problem: Its per capita generation of waste was among the highest in Europe and rising; it was running out of landfill space, with Copenhagen set to exhaust its landfill capacity in a short time; and there was a great deal of concern about air...... pollution from incinerators. Denmark responded to this situation by adopting a comprehensive waste management policy that included an innovative tax on waste designed to promote the reuse and recycling of many types of waste. Now that the tax has been in place for a decade, there is enough data to assess...... its effectiveness. Such an assessment has implications that extend far beyond Denmark. To date, six other countries in Europe (Austria, Belgium, Finland, France, the Netherlands, and the United Kingdom) have adopted waste taxes at the national level, and two others (Norway and Sweden) are considering...

  4. Physico-chemical and bacteriological quality assessment of shallow wells in Kitui town, Kenya

    Directory of Open Access Journals (Sweden)

    Romulus Abila

    2012-03-01

    Full Text Available Kitui town, a small but fast growing town in arid south-eastern Kenya faces unreliable water supply and residents are highly dependent on shallow wells as the main source of water for domestic use. A study was carried out to assess the physical-chemical and bacteriological quality of water from shallow wells within the town’s main residential areas. 96 water samples were collected from 8 main residential estates within the town between May and July 2011 and analysed for physical-chemical characteristics and bacterial quantity and species. Water analysis revealed presence of 9 pathogenic genera including Salmonella, Escherichia coli, Vibrio, Listeria, Staphylococcus, Streptococcus, Enterobacter, Klebsiella and Pseudomonas. Multiple-tube fermentation technique was used to enumerate coliform bacteria in water. Total aerobic bacterial load ranged from 3.70 x102 to 2.352 x103 CFU/ml. E. Coli was isolated from Majengo and Mjini estates only and the bacterial load estimated as 1.10 x102 CFU/ml and 0.20 x102 CFU/ml respectively while Salmonella sp. was isolated from water samples from Kunda Kindu, JICA and Mjini estates. Conductivity and pH levels were above World Health Organization acceptable levels for drinking water in all samples. All samples tested did not meet the WHO bacteriological standards for drinking water. The presence of Salmonella, Vibrio, Listeria and E. Coli should particularly raise serious public health concerns over the quality of the town’s shallow wells water. Intervention measures including creating awareness and educating residents on shallow well construction, citing and care, boiling of water and improving sanitation should be urgently instituted. There is also need to construct sewerage works for the rapidly expanding Kitui town to reduce incidences of contamination from septic tanks.

  5. Modeling Electric Double-Layers Including Chemical Reaction Effects

    DEFF Research Database (Denmark)

    Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

    2014-01-01

    A physicochemical and numerical model for the transient formation of an electric double-layer between an electrolyte and a chemically-active flat surface is presented, based on a finite elements integration of the nonlinear Nernst-Planck-Poisson model including chemical reactions. The model works...

  6. Assessment of the toxicity of wastewater from the metalworking industry treated using a conventional physico-chemical process.

    Science.gov (United States)

    Machado, Rodrigo Matuella; Monteggia, Luiz Olinto; Arenzon, Alexandre; Curia, Ana Cristina

    2016-06-01

    This article presents results from a toxicity reduction evaluation program intended to describe wastewater from the metalworking industry that was treated using a conventional physico-chemical process. The toxicity of the wastewater for the microcrustacean Daphnia magna was predominantly expressive. Alkaline cyanide wastewater generated from electroplating accounted for the largest number of samples with expressive toxicity. When the raw wastewater concentrations in the batches were repeated, inexpressive toxicity variations were observed more frequently among the coagulated-flocculated samples. At the coagulation-flocculation step, 22.2 % of the treatments had reduced acute toxicity, 30.6 % showed increased toxicity, and 47.2 % remained unchanged. The conductivity and total dissolved solids contents of the wastewater indicated the presence of salts with charges that were inappropriate for the survival of daphnid. The wastewaters treated by neutralization and coagulation-flocculation had average metallic compound contents that were greater than the reference toxic concentrations reported in other studies, suggesting that metals likely contributed to the toxic effects of the wastewater on freshwater microcrustaceans. Thus, alternative coagulants and flocculants should be assessed, and feasible doses should be determined to improve wastewater treatment. In addition, advanced treatment processes should be assessed for their abilities to remove dissolved toxic salts and ions.

  7. Effect of prolonged chemical challenges on selected properties of silorane

    DEFF Research Database (Denmark)

    de Jesus, Vivian CBR; Martinelli, Natan Luiz; Pascotto, Renata Corrêa;

    Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on water sorption, solubility, and roughness of a silorane-based material when compared to methacrylate-based composites. Methods: Initial roughness and mass were registered for specimens (n=24......) fabricated from methacrylate (Filtek Z250, 3M ESPE; Filtek Z350XT, 3M ESPE; Master Fill, Biodinâmica) or silorane-based (Filtek P90, 3M ESPE) composites. The volume of all specimens was also calculated. Specimens were divided in four groups (n=6) and individually stored at 37°C in 0.02N citric acid, 0.02N...... submitted to two-way analysis of variance or analysis of variance for repeated measures, and Tukey’s multiple comparison test (a=0.05). Results: The silorane-based composite was the roughest (pcomposite (Ra=0.06±0.01) when compared to the other investigated materials (Ra=0.05±0.01). Significant...

  8. The Chemical Effects of Mutual Shielding in Photon Dominated Regions

    CERN Document Server

    Rollins, Richard P

    2012-01-01

    We investigate the importance of the shielding of chemical photorates by molecular hydrogen photodissociation lines and the carbon photoionization continuum deep within models of photon dominated regions. In particular, the photodissociation of N2 and CN are significantly shielded by the H2 photodissociation line spectrum. We model this by switching off the photodissociation channels for these species behind the HI to H2 transition. We also model the shielding effect of the carbon photoionization continuum as an attenuation of the incident radiation field shortwards of 1102\\AA. Using recent line and continuum cross section data, we present calculations of the direct and cosmic ray induced photorates for a range of species, as well as optically thick shielding factors for the carbon continuum. Applying these to a time dependent PDR model we see enrichments in the abundances of N2, N2H+, NH3 and CN by factors of roughly 3-100 in the extinction band Av=2.0 to Av=4.0 for a range of environments. While the precise...

  9. New chemical evolution analytical solutions including environment effects

    CERN Document Server

    Spitoni, E

    2015-01-01

    In the last years, more and more interest has been devoted to analytical solutions, including inflow and outflow, to study the metallicity enrichment in galaxies. In this framework, we assume a star formation rate which follows a linear Schmidt law, and we present new analytical solutions for the evolution of the metallicity (Z) in galaxies. In particular, we take into account environmental effects including primordial and enriched gas infall, outflow, different star formation efficiencies, and galactic fountains. The enriched infall is included to take into account galaxy-galaxy interactions. Our main results can be summarized as: i) when a linear Schmidt law of star formation is assumed, the resulting time evolution of the metallicity Z is the same either for a closed-box model or for an outflow model. ii) The mass-metallicity relation for galaxies which suffer a chemically enriched infall, originating from another evolved galaxy with no pre-enriched gas, is shifted down in parallel at lower Z values, if co...

  10. Biosorption of heavy metal ions from aqueous solutions by short hemp fibers: Effect of chemical composition.

    Science.gov (United States)

    Pejic, Biljana; Vukcevic, Marija; Kostic, Mirjana; Skundric, Petar

    2009-05-15

    Sorption potential of waste short hemp fibers for Pb(2+), Cd(2+) and Zn(2+) ions from aqueous media was explored. In order to assess the influence of hemp fiber chemical composition on their heavy metals sorption potential, lignin and hemicelluloses were removed selectively by chemical modification. The degree of fiber swelling and water retention value were determined in order to evaluate the change in accessibility of the cell wall components to aqueous solutions due to the fiber modification. The effects of initial ion concentration, contact time and cosorption were studied in batch sorption experiments. The obtained results show that when the content of either lignin or hemicelluloses is progressively reduced by chemical treatment, the sorption properties of hemp fibers are improved. Short hemp fibers are capable of sorbing metal ions (Pb(2+), Cd(2+) and Zn(2+)) from single as well as from ternary metal ion solutions. The maximum total uptake capacities for Pb(2+), Cd(2+) and Zn(2+) ions from single solutions are the same, i.e. 0.078mmol/g, and from ternary mixture 0.074, 0.035 and 0.035mmol/g, respectively.

  11. Chemical speciation of trace metals emitted from Indonesian peat fires for health risk assessment

    Science.gov (United States)

    Betha, Raghu; Pradani, Maharani; Lestari, Puji; Joshi, Umid Man; Reid, Jeffrey S.; Balasubramanian, Rajasekhar

    2013-03-01

    Regional smoke-induced haze in Southeast Asia, caused by uncontrolled forest and peat fires in Indonesia, is of major environmental and health concern. In this study, we estimated carcinogenic and non-carcinogenic health risk due to exposure to fine particles (PM2.5) as emitted from peat fires at Kalimantan, Indonesia. For the health risk analysis, chemical speciation (exchangeable, reducible, oxidizable, and residual fractions) of 12 trace metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn) in PM2.5 was studied. Results indicate that Al, Fe and Ti together accounted for a major fraction of total metal concentrations (~ 83%) in PM2.5 emissions in the immediate vicinity of peat fires. Chemical speciation reveals that a major proportion of most of the metals, with the exception of Cr, Mn, Fe, Ni and Cd, was present in the residual fraction. The exchangeable fraction of metals, which represents their bioavailability, could play a major role in inducing human health effects of PM2.5. This fraction contained carcinogenic metals such as Cd (39.2 ng m- 3) and Ni (249.3 ng m- 3) that exceeded their WHO guideline values by several factors. Health risk estimates suggest that exposure to PM2.5 emissions in the vicinity of peat fires poses serious health threats.

  12. Occurrence and Assessment of Chemical Contaminants in Drinking Water in Tunceli, Turkey

    Directory of Open Access Journals (Sweden)

    Veysel Demir

    2013-01-01

    Full Text Available The objective of this study was to analyze drinking water samples from 21 sites in the city center and seven municipalities of Tunceli, Turkey, in order to determine the presence of nitrate, nitrite, fluoride, bromate, pesticides, polycyclic aromatic hydrocarbons (PAHs, trihalomethanes (THMs, and some other chemicals. In all locations, the concentrations of chemicals investigated were below the permissible limits set by local and international organizations for drinking water. Low levels of nitrate (4.79 ± 4.20 mg/L, fluoride (0.11 ± 0.08 mg/L, and THMs (6.63 ± 5.14 μg/L were detected in all locations. A low level of tetra, chloroethane, which is suspected to be a human carcinogen, was also detected in 8 locations in the range of 0.26–0.43 μg/L. These contaminants may pose adverse health effects or minimum hazard due to long-term exposure. In all locations, bromate, benzene, total PAH, 1-2 dichloroethane, vinyl chloride, acrylamide, and epichloridine levels in drinking water samples were under detection limits.

  13. [Systematization of data and information on delayed consequences of the effects of chemicals in humans].

    Science.gov (United States)

    Ianno, L V; Pimenova, M N; Osipova, I V

    1993-01-01

    The systematization and analysis of the data connected with delayed consequences arising in human body from exposure to dangerous chemicals have been carried out. The paper contains the list of dangerous chemicals exerting mutagenic or carcinogenic effects and chromosome aberrations. The cytologic express method of revealing mucous membrane dysplasia resulting from exposure to some chemical mutagens have been evaluated.

  14. A Framework for Assessing Chemical/Nonchemical Interactions: A Case Study of Lead and Psychosocial Stress

    Science.gov (United States)

    Chemical and nonchemical stressors may contribute to negative health consequences in certain individuals. Nonchemical stressors include poverty, crowding, noise, and exposure to violence. Research has suggested that some nonchemical stressors may alter chemical toxicity. We propo...

  15. Effect of 20 % EDTA Aqueous Solution on Defective Tubes (Alloy600) in High Temperature Chemical Cleaning Environments

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyuk Chul [KHNP-CRI, Daejeon (Korea, Republic of)

    2016-04-15

    The transport and deposition of corrosion products in pressurized water nuclear reactor (PWR) steam generators have led to corrosion (SCC, denting etc.) problems. Lancing, mechanical cleaning and chemical cleaning have been used to reduce these problems. The methods of lancing and mechanical cleaning have limitations in removing corrosion products due to the structure of steam generator tubes. But high temperature chemical cleaning (HTCC) with EDTA is the most effective method to remove corrosion products regardless of the structure. However, EDTA in chemical cleaning aqueous solution and chemical cleaning environments affects the integrity of materials used in steam generators. The nuclear power plants have to perform the pre-test (also called as qualification test (QT)) that confirms the effect on the integrity of materials after HTCC. This is one of the series studies that assess the effect, and this study determines the effects of 20 % EDTA aqueous solution on defective tubes in high temperature chemical cleaning environments. The depth and magnitude of defects in steam generator (SG) tubes were measured by eddy current test (ECT) signals. Surface analysis and magnitude of defects were performed by using SEM/EDS. Corrosion rate was assessed by weight loss of specimens. The ECT signals (potential and depth %) of defective tubes increased marginally. But the lengths of defects, oxides on the surface and weights of specimens did not change. The average corrosion rate of standard corrosion specimens was negligible. But the surfaces on specimens showed traces of etching. The depth of etching showed a range on the nanometer. After comprehensive evaluation of all the results, it is concluded that 20 % EDTA aqueous solution in high temperature chemical cleaning environments does not have a negative effect on defective tubes.

  16. Chemical and biological oxidative effects of carbon black nanoparticles.

    Science.gov (United States)

    Koike, Eiko; Kobayashi, Takahiro

    2006-11-01

    Several studies show that ultrafine particles have a larger surface area than coarse particles, thus causing a greater inflammatory response. In this study, we investigated chemical and biological oxidative effects of nanoparticles in vitro. Carbon black (CB) nanoparticles with mean aerodynamic diameters of 14, 56, and 95nm were examined. The innate oxidative capacity of the CB nanoparticles was measured by consumption of dithiothreitol (DTT) in cell-free system. The expression of heme oxygenase-1 (HO-1) in rat alveolar type II epithelial cell line (SV40T2) and alveolar macrophages (AM) exposed to CB nanoparticles was measured by ELISA. DTT consumption of 14nm CB was higher than that of other CB nanoparticles having the same particle weight. However, DTT consumption was directly proportional to the particle surface area. HO-1 protein in SV40T2 cells was significantly increased by the 14nm and 56nm CB, however, 95nm CB did not affect. HO-1 protein in AM was significantly increased by the 14, 56, and 95nm CB. The increase in HO-1 expression was diminished by N-acetyl-l-cysteine (NAC) treatment of each CB nanoparticles before exposure although the difference between the effects of NAC-treated and untreated 14nm CB did not achieve significant. In conclusion, CB nanoparticles have innate oxidative capacity that may be dependent on the surface area. CB nanoparticles can induce oxidative stress in alveolar epithelial cells and AM that is more prominent with smaller particles. The oxidative stress may, at least partially, be mediated by surface function of particles.

  17. Sub-50 nm metrology on extreme ultra violet chemically amplified resist--A systematic assessment.

    Science.gov (United States)

    Maas, D J; Fliervoet, T; Herfst, R; van Veldhoven, E; Meessen, J; Vaenkatesan, V; Sadeghian, H

    2015-10-01

    With lithographic patterning dimensions decreasing well below 50 nm, it is of high importance to understand metrology at such small scales. This paper presents results obtained from dense arrays of contact holes (CHs) with various Critical Dimension (CD) between 15 and 50 nm, as patterned in a chemically amplified resist using an ASML EUV scanner and measured at ASML and TNO. To determine the differences between various (local) CD metrology techniques, we conducted an experiment using optical scatterometry, CD-Scanning Electron Microscopy (CD-SEM), Helium ion Microscopy (HIM), and Atomic Force Microscopy (AFM). CD-SEM requires advanced beam scan strategies to mitigate sample charging; the other tools did not need that. We discuss the observed main similarities and differences between the various techniques. To this end, we assessed the spatial frequency content in the raw images for SEM, HIM, and AFM. HIM and AFM resolve the highest spatial frequencies, which are attributed to the more localized probe-sample interaction for these techniques. Furthermore, the SEM, HIM, and AFM waveforms are analyzed in detail. All techniques show good mutual correlation, albeit the reported CD values systematically differ significantly. HIM systematically reports a 25% higher CD uniformity number than CD-SEM for the same arrays of CHs, probably because HIM has a higher resolution than the CD-SEM used in this assessment. A significant speed boost for HIM and AFM is required before these techniques are to serve the demanding industrial metrology applications like optical critical dimension and CD-SEM do nowadays.

  18. Screening of herbal extracts influencing hematopoiesis and their chemical genetic effects in embryonic zebrafish

    Institute of Scientific and Technical Information of China (English)

    Rajaretinam Rajesh Kannan; Samuel Gnana Prakash Vincent

    2012-01-01

    Objective: To screen the herbal extracts influencing the hematopoietic stem cells (HSC) in zebrafish embryos and their chemical genetic effects. Methods: The herbals used in this study had been widely applicable in Siddha medicines in South India. Herbal extracts were treated in zebrafish embryos at 4 d post fertilization and the extracts inducing the HSC were enumerated in hemocytometer. The biocompatibility and the organogenesis of the screened extracts were assessed in the zebrafish embryos for their chemical genetic effects. The LC50 values were calculated with their parallel control. The blood cells were enumerated. Results: The level of RBC was found increased in the Bergera koenigii (B. koenigii) at 15 μg/mL (P<0.05), Mimosa pudica (M. pudica) at 20 μg/mL (P<0.05) and Solanum trilobatum (S. trilobatum) at 25 μg/mL (P<0.05) and decreased RBC level was found in Phyllanthus niruri (P. niruri) at 30 μg/mL (P<0.05). The WBC count was found increased in S. trilobatum at 20 μg/mL (P<0.05) and Annona muricata (Annona muricata) at 15 μg/mL (P<0.05) and the Vitis quadrangularis (V. quadrangularis) at 20 μg/mL (P<0.05) decreased the WBC level. There were no notable effects in heart beats and the chemical genetic effects were observed at higher concentration of the extract resulting in Pericardial bulging, trunk tail flexure with heart edema, fin fold deformities etc. Conclusions: This in vivo based screening of Hematopoiesis is an inexpensive assay to screen herbal compounds and found that S. trilobatum extract influenced embryonic HSC in zebrafish, which could be a therapeutic for blood related disorders.

  19. Modeling assessment for ammonium nitrogen recovery from wastewater by chemical precipitation

    Institute of Scientific and Technical Information of China (English)

    Tao Zhang; Qiucheng Li; Lili Ding; Hongqiang Ren; Ke Xu; Yonggang Wu; Dong Sheng

    2011-01-01

    Chemical precipitation to form magnesium ammonium phosphate (MAP) is an effective technology for recovering ammonium nitrogen (NH4+-N). In the present research, we investigated the thermodynamic modeling of the PHREEQC program for NH4+-N recovery to evaluate the effect of reaction factors on MAP precipitation. The case study of NH4+-N recovery from coking wastewater was conducted to provide a comparison. Response surface methodology (RSM) was applied to assist in understanding the relative significance of reaction factors and the interactive effects of solution conditons. Thermodynamic modeling indicated that the saturation index (SI) of MAP followed a polynomial function of pH. The SI of MAP increased logarithmically with the Mg2+/NH4+ molar ratio (Mg/N) and the initial NH4+-N concentration (CN), respectively, while it decreased with an increase in Ca2+/NH4+ and CO32-/NH4+molar ratios (Ca/N and CO32-/N), respectively. The trends for NH4+-N removal at different pH and Mg/N levels were similar to the thermodynamic modeling predictions. The RSM analysis indicated that the factors including pH, Mg/N, CN, Ca/N, (Mg/N)× (CO32-/N),(pH)2, (Mg/N)2, and (CN)2 were significant. Response surface plots were useful for understanding the interaction effects on NH4+-Nrecovery.

  20. Application of the Activity Framework for Assessing Aquatic Ecotoxicology Data for Organic Chemicals

    DEFF Research Database (Denmark)

    Thomas, Paul; Dawick, James; Lampi, Mark;

    2015-01-01

    Toxicological research in the 1930s gave the first indications of the link between narcotic toxicity and the chemical activity of organic chemicals. More recently, chemical activity has been proposed as a novel exposure parameter that describes the fraction of saturation and that quantifies the p...

  1. Assessing the effectiveness of climate adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Simon

    2011-10-15

    As governments and other agencies spend more money on adaptation to climate change they want to know that their investments are effective — that adaptation will keep development on track, that there is a fair distribution of costs and benefits, and that climate resilience is being built. But monitoring and evaluating adaptation policy and practice is not easy. Some approaches are unhelpful because they fail to integrate adaptation and development, use purely quantitative methods and do not include the perspectives of climate-vulnerable groups in their assessments. Enabling countries and organisations to effectively evaluate adaptation requires an inclusive approach built on sharing knowledge among all stakeholders — one that can capture behavioural and institutional changes and that answers to the needs of the climate-vulnerable poor.

  2. Effect of plant chemicals on the behavior of the Mediterranean fruit fly

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, N.T., E-mail: nikopap@uth.g [University of Thessaly (Greece). Dept. of Crop Production and Rural Environment. Lab. of Entomology and Agricultural Zoology; Kouloussis, N.A.; Katsoyannos, B.I. [University of Thessaloniki, Thessaloniki (Greece). School of Agriculture

    2006-07-01

    A review of current information on the relation between plant chemicals and the Mediterranean fruit fly is presented. The influence of age and adult physiology on the response of med flies to plant chemicals is studied. The effect of plant chemicals on med fly behavior during host finding, mating and oviposition is analysed. The possible influence of plant chemicals on the dispersion patterns and spatial distribution of the fly is also addressed. (MAC)

  3. Assessment of microbiological and chemical properties in a municipal landfill area.

    Science.gov (United States)

    Frączek, Krzysztof J; Ropek, Dariusz R; Lenart-Boroń, Anna M

    2014-01-01

    This study aimed at determining the environmental hazards for soils posed by a large municipal landfilll. The concentrations of heavy metals and Policyclic Aromatic Hydrocarbons, as well as microbial composition (i.e., mesophilic bacteria, actinomycetes, molds, Salmonella, Staphylococcus, Clostridium perfringens) in four soils within and in the vicinity of the landfill were evaluated and compared to waste samples. Both chemical and microbiological analyses revealed only limited contamination of surrounding areas. Although the increased alkalinity of soils was detected, the concentrations of heavy metals and Polycyclic Aromatic Hydrocarbons (PAHs) did not exceed the admissible values. All examined microbial groups were abundant in soil and waste. The highest microbial cell numbers were observed in warm summer and spring months. Although the site south of the landfill shows no trace of microbial contamination, pathogenic bacteria were found north of the landfill. This may suggest that there are other, more effective, transmission routes of bacteria than groundwater flow.

  4. Chemical information media in the chemistry lecture hall: a comparative assessment of two online encyclopedias.

    Science.gov (United States)

    Korosec, Lukas; Limacher, Peter Andreas; Lüthi, Hans Peter; Brändle, Martin Paul

    2010-01-01

    The chemistry encyclopedia Römpp Online and the German universal encyclopedia Wikipedia were assessed by first-year university students on the basis of a set of 30 articles about chemical thermodynamics. Criteria with regard to both content and form were applied in the comparison; 619 ratings (48% participation rate) were returned. While both encyclopedias obtained very good marks and performed nearly equally with regard to their accuracy, the average overall mark for Wikipedia was better than for Römpp Online, which obtained lower marks with regard to completeness and length. Analysis of the results and participants' comments shows that students attach importance to completeness, length and comprehensibility rather than accuracy, and also attribute less value to the availability of sources which validate an encyclopedia article. Both encyclopedias can be promoted as a starting reference to access a topic in chemistry. However, it is recommended that instructors should insist that students do not rely solely on encyclopedia texts, but use and cite primary literature in their reports.

  5. Chemical and biological assessment of two offshore drilling sites in the Alaskan Arctic.

    Science.gov (United States)

    Trefry, John H; Dunton, Kenneth H; Trocine, Robert P; Schonberg, Susan V; McTigue, Nathan D; Hersh, Eric S; McDonald, Thomas J

    2013-05-01

    A retrospective chemical and biological study was carried out in Camden Bay, Alaskan Beaufort Sea, where single exploratory oil wells were drilled at two sites more than two decades ago. Barium from discharged drilling mud was present in sediments at concentrations as high as 14%, ~200 times above background, with significantly higher concentrations of Ba, but not other metals, within 250 m of the drilling site versus reference stations. Elevated concentrations of Cr, Cu, Hg and Pb were found only at two stations within 25 m of one drilling site. Concentrations of total polycyclic aromatic hydrocarbons (TPAH) were not significantly different at reference versus drilling-site stations; however, TPAH were elevated in Ba-rich layers from naturally occurring perylene in ancient formation cuttings. Infaunal biomass and species abundance were not significantly different at reference versus drilling-site stations; infauna were less diverse at drilling-site stations. Our assessment showed that discharges from single wells within large areas caused minimal long-term, adverse impacts to the benthic ecosystem.

  6. Chemical Criteria to Assess Risk of Phosphorus Leaching from Urban Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gan-Lin; W. BURGHARDT; YANG Jin-Ling

    2005-01-01

    Soils from urban and suburban areas are normally enriched with phosphorus (P). Sixteen urban soils with a wide range of total P concentrations under typical urban land uses were sampled and analyzed for extractable P concentrations using water, sodium bicarbonate and citric acid. Meanwhile the soils were artificially leached in columns and P concentrations in the leachates were determined. With linear regression a two-stage linear relationship was found to exist between concentrations of P in the leachates and soil P contents obtained by various chemical measurements, i.e., there was a "change-point" denoting the critical threshold value for extractable P between the regression lines, above which concentrations of P in leachates increased substantially. These threshold "change-point" values were 1.5 mg kg-1 for water-soluble P and CaC12-P, 25 mg kg-1 for Olsen-P, and 250-350 mg kg-1 for citric acid-P with the sharpest change and the best predictor [r2 (upper) = 0.928, r2 (lower)= 0.807] appearing for Olsen-P. These "change-points" were considered important criteria in assessing the risk of P leaching from urban soils and could be used as standards to delineate and target hazardous areas in urban and suburban areas.

  7. Hydro-chemical assessment and groundwater recharge mechanism in the humid tropics: a case study.

    Science.gov (United States)

    Hameed, A Shahul; Prasad, N B Narasimha

    2008-10-01

    The study related to assessment of various chemical constituents in the groundwater, their origin and suitability for human use has been carried out in the Chaliyar river basin of Kerala (India). Groundwater samples were collected from 27 open dug wells and 7 bore wells, and analyzed. Piper tri-linear classification was followed in segregating the data with respect to source of dissolved constituents in groundwater. Most of the wells fall within the no dominant ion zone in the piper diagram, indicating the equal distribution of alkalis and alkaline earths. High level of dissolved solids, with the presence of chloride and sulphate, was observed in a few wells in the coastal region, which may be due to the salinity intrusion from the sea. The groundwater quality was found fairly good and potable in the lateritic midland region, except for a few wells, which were having significant level of nitrate and/or chloride. An attempt has been made to understand the source of groundwater recharge in the basin using environmental tritium as a tracer. It has been observed that the groundwater is predominantly recharged through rainfall, as evidenced from the level of tritium close to that of local precipitation.

  8. [Harmonization with international approaches to guidance documents on methods of assessment of the mutagenic properties of chemical environmental factors].

    Science.gov (United States)

    Zhurkov, V S; Sycheva, L P; Ingel', F I; Akhal'tseva, L V; Iurchenko, V V

    2013-01-01

    Evaluation of mutagenic activity--an indispensable element of the toxicological characteristics of chemicals in their hygienic regulation. In the article there is performed an analysis of the adopted in the Organization for Economic Cooperation and Development (OECD) and in Russia guidance documents on methods of assessment of the mutagenic properties of chemicals. In the OECD there are 17 manuals, each of which describes a single method, in Russia there were approved five guidance documents for specific groups of chemicals (drugs, pesticides, nanomaterials, substances normalized in the water and the air), which represent the basic and auxiliary methods of testing mutagens. Basic methods aimed to the evaluation of gene, chromosomal and genomic mutations include: assessment of gene mutations in bacteria, methods for estimating mutations in cell cultures of human and mammals in vitro, methods for inspecting mutations in somatic and germ cells of mammals in vivo. Analysis of Russian documents shows that the protocols of basic tests of assessment of the mutagenic activity are close to the protocols of the OECD. It is necessary to publish guidance documents on tests of assessment of the mutagenic activity of chemicals harmonized with the OECD documents.

  9. Integrating mechanistic and polymorphism data to characterize human genetic susceptibility for environmental chemical risk assessment in the 21st century

    Science.gov (United States)

    Response to environmental chemicals can vary widely among individuals and between population groups. In human health risk assessment, data on susceptibility can be utilized by deriving risk levels based on a study of a susceptible population and/or an uncertainty factor may be ap...

  10. A quest for the right order : biodegradation rates in the scope of environmental risk assessment of chemicals

    NARCIS (Netherlands)

    Blok, Johan

    2001-01-01

    The biodegradation of chemicals in sewage treatment plants is a key issue of environmental risk assessment. To predict the residual concentration the rate of the biodegradation process has to be estimated. This rate is the result of microbial adaptation of the micro-flora in the system. Therefore th

  11. European alerting and monitoring data as inputs for the risk assessment of microbiological and chemical hazards in spices and herbs

    NARCIS (Netherlands)

    Banach, J.L.; Stratakou, I.; Fels-Klerx, van der H.J.; Besten, den H.M.W.; Zwietering, M.H.

    2016-01-01

    Food chains are susceptible to contaminations from food-borne hazards, including pathogens and chemical contaminants. An assessment of the potential product-hazard combinations can be supported by using multiple data sources. The objective of this study was to identify the main trends of food saf

  12. Evaluation of semi-generic PBTK modeling for emergency risk assessment after acute inhalation exposure to volatile hazardous chemicals

    NARCIS (Netherlands)

    Olie, J. Daniël N; Bessems, Jos G.; Clewell, Harvey J.; Meulenbelt, Jan; Hunault, Claudine C.

    2015-01-01

    BACKGROUND: Physiologically Based Toxicokinetic Models (PBTK) may facilitate emergency risk assessment after chemical incidents with inhalation exposure, but they are rarely used due to their relative complexity and skill requirements. We aimed to tackle this problem by evaluating a semi-generic PBT

  13. Regulation of endocrine-disrupting chemicals: critical overview and deficiencies in toxicology and risk assessment for human health.

    Science.gov (United States)

    Harvey, Philip W; Everett, David J

    2006-03-01

    Regulation of endocrine-disrupting chemicals is reviewed in terms of hazard assessment (regulatory toxicology) and risk assessment. The current range of regulatory general toxicology protocols can detect endocrine toxicity, but specific endocrine toxicology tests are required to confirm mechanisms (e.g. oestrogenic, anti-androgenic). Strategies for validating new endocrine toxicology protocols and approaches to data assessment are discussed, and deficiencies in regulatory toxicology testing (e.g. lack of adrenocortical function assessment) identified. Recent evidence of a role of prolactin in human breast cancer also highlights deficiencies in regulatory evaluation. Actual human exposure to chemicals and the high-exposure example of chemicals in body-care cosmetics is reviewed with reference to evidence that common ingredients (e.g. parabens, cyclosiloxanes) are oestrogenic. The hypothesis and epidemiology concerning chemical exposure from body-care cosmetics (moisturizers, lotions, sun screens, deodorants) and breast cancer in women is reviewed, applying Bradford-Hill criteria for association and causality, and research requirements are identified.

  14. Harmonisation of food consumption data format for dietary exposure assessments of chemicals analysed in raw agricultural commodities

    DEFF Research Database (Denmark)

    Boon, Polly E.; Ruprich, Jiri; Petersen, Annette

    2009-01-01

    In this paper, we present an approach to format national food consumption data at raw agricultural commodity (RAC) level. In this way, the data is both formatted in a harmonised way given the comparability of RACs between countries, and suitable to assess the dietary exposure to chemicals analysed...

  15. Endocrine-disrupting chemicals and oil and natural gas operations: Potential environmental contamination and recommendations to assess complex environmental mixtures

    Science.gov (United States)

    Kassotis, Christopher D.; Tillitt, Donald E.; Lin, Chung-Ho; McElroy, Jane A.; Nagel, Susan C.

    2015-01-01

    Background: Hydraulic fracturing technologies, developed over the last 65 years, have only recently been combined with horizontal drilling to unlock oil and gas reserves previously deemed inaccessible. While these technologies have dramatically increased domestic oil and natural gas production, they have also raised concerns for the potential contamination of local water supplies with the approximately 1,000 chemicals used throughout the process, including many known or suspected endocrine-disrupting chemicals.Objectives: We discuss the need for an endocrine component to health assessments for drilling-dense regions in the context of hormonal and anti-hormonal activities for chemicals used.Methods: We discuss the literature on 1) surface and ground water contamination by oil and gas extraction operations, and 2) potential human exposure, particularly in context of the total hormonal and anti-hormonal activities present in surface and ground water from natural and anthropogenic sources, with initial analytical results and critical knowledge gaps discussed.Discussion: In light of the potential for environmental release of oil and gas chemicals that can disrupt hormone receptor systems, we recommend methods for assessing complex hormonally active environmental mixtures.Conclusions: We describe a need for an endocrine-centric component for overall health assessments and provide supporting information that using this may help explain reported adverse health trends as well as help develop recommendations for environmental impact assessments and monitoring programs.

  16. Metabolic Effect Level Index Links Multivariate Metabolic Fingerprints to Ecotoxicological Effect Assessment.

    Science.gov (United States)

    Riedl, Janet; Schreiber, René; Otto, Matthias; Heilmeier, Hermann; Altenburger, Rolf; Schmitt-Jansen, Mechthild

    2015-07-07

    A major goal of ecotoxicology is the prediction of adverse outcomes for populations from sensitive and early physiological responses. A snapshot of the physiological state of an organism can be provided by metabolic fingerprints. However, to inform chemical risk assessment, multivariate metabolic fingerprints need to be converted to readable end points suitable for effect estimation and comparison. The concentration- and time-dependent responsiveness of metabolic fingerprints to the PS-II inhibitor isoproturon was investigated by use of a Myriophyllum spicatum bioassay. Hydrophilic and lipophilic leaf extracts were analyzed with gas chromatography-mass spectrometry (GC-MS) and preprocessed with XCMS. Metabolic changes were aggregated in the quantitative metabolic effect level index (MELI), allowing effect estimation from Hill-based concentration-response models. Hereby, the most sensitive response on the concentration scale was revealed by the hydrophilic MELI, followed by photosynthetic efficiency and, 1 order of magnitude higher, by the lipophilic MELI and shoot length change. In the hydrophilic MELI, 50% change compares to 30% inhibition of photosynthetic efficiency and 10% inhibition of dry weight change, indicating effect development on different response levels. In conclusion, aggregated metabolic fingerprints provide quantitative estimates and span a broad response spectrum, potentially valuable for establishing adverse outcome pathways of chemicals in environmental risk assessment.

  17. Antifoaming effect of chemical compounds in manure biogas reactors

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Tsapekos, Panagiotis; Boe, Kanokwan;

    2013-01-01

    ), siloxanes (polydimethylsiloxane) and ester (tributylphosphate) were found to be the most efficient compounds to suppress foam. The efficiency of antifoamers was dependant on their physicochemical properties and greatly correlated to their chemical characteristics for dissolving foam. The antifoamers were...

  18. On Diffused Pollution Effect of Chemical Fertilizers in Chongqing Municipality

    Institute of Scientific and Technical Information of China (English)

    Limeng; GU; Lianchao; YU; Qian; BI

    2015-01-01

    Improper use of chemical fertilizers is an essential reason for diffused pollution of agriculture. Therefore,finding out influence factors of farmers in application of chemical fertilizers will play a significant role in controlling the diffused pollution of agriculture. Through field survey,a total of 340 samples in 4 counties of Chongqing Municipality were obtained. On the basis of these samples,an empirical study was carried out. The study results indicate that farmers’ application of chemical fertilizers is negatively correlated with farmers’ age,education level,male labor proportion,and soil fertility,while the annual family income,agricultural production population proportion,commodity trading characteristics,and scientific fertilizer application ability fail to pass the significance test. These results will provide reference for proper application of chemical fertilizers and controlling diffused pollution.

  19. Effect of chemical polishing in titanium materials for low outgassing

    Science.gov (United States)

    Ishizawa, K.; Kurisu, H.; Yamamoto, S.; Nomura, T.; Murashige, N.

    2008-03-01

    A chemical polishing using a nitric acid solution was found to be the most suitable for the titanium materials. 1.8 nm of small surface roughness was observed in a microscopic range in 1 μm square, and 7 nm of a thin oxide layer was shown to exist for the chemically polished titanium. The surface processing for the titanium was developed combining the chemical polishing and the precision cleaning. The chemically polished pure titanium of JIS grade 2 showed extremely low outgassing rate below 10-12 Pams-1 after baking process, which is two orders of magnitude smaller than that for standard vacuum materials under the same baking condition. Outgassing rates of the titanium is about 1/5 of that for a stainless steel without baking process.

  20. Effect of chemical polishing in titanium materials for low outgassing

    Energy Technology Data Exchange (ETDEWEB)

    Ishizawa, K; Kurisu, H; Yamamoto, S [Graduate School of Science and Engineering, Yamaguchi University, Ube, Yamaguchi 755-8611 (Japan); Nomura, T; Murashige, N [CT division San-ai Plant Industries, Ltd, Kawasaki, Kanagawa 210-0821 (Japan)], E-mail: kishizawa@san-ai-oil.co.jp

    2008-03-01

    A chemical polishing using a nitric acid solution was found to be the most suitable for the titanium materials. 1.8 nm of small surface roughness was observed in a microscopic range in 1 {mu}m square, and 7 nm of a thin oxide layer was shown to exist for the chemically polished titanium. The surface processing for the titanium was developed combining the chemical polishing and the precision cleaning. The chemically polished pure titanium of JIS grade 2 showed extremely low outgassing rate below 10{sup -12} Pams{sup -1} after baking process, which is two orders of magnitude smaller than that for standard vacuum materials under the same baking condition. Outgassing rates of the titanium is about 1/5 of that for a stainless steel without baking process.

  1. Integrating Product Water Quality Effects In Holistic Assessments Of Water Systems

    DEFF Research Database (Denmark)

    Rygaard, Martin

    2011-01-01

    economic assessment of water quality effects, production costs and environmental costs (water abstraction and CO2-emissions). Considered water quality issues include: health (dental caries, cardiovascular diseases, eczema), corrosion (lifetime of appliances, pipes), consumption of soap, and bottled water......While integrated assessments of sustainability of water systems are largely focused on quantity issues, chemical use, and energy consumption, effects of the supplied water quality are often overlooked. Drinking water quality affects corrosion rates, human health, applicability of water...... and aesthetics. Even small changes in the chemical composition of water may accumulate large impacts on city scale. Here, a method for integrated assessment of water quality is presented. Based on dose-response relationships a range of effects from different drinking water qualities is merged into a holistic...

  2. Cognitive effects of endocrine-disrupting chemicals in animals.

    OpenAIRE

    Schantz, S L; Widholm, J J

    2001-01-01

    A large number of chemical pollutants including phthalates, alkylphenolic compounds, polychlorinated biphenyls and polychlorinated dibenzodioxins, organochlorine pesticides, bisphenol A, and metals including lead, mercury, and cadmium have the ability to disrupt endocrine function in animals. Some of these same chemicals have been shown to alter cognitive function in animals and humans. Because hormonally mediated events play a central role in central nervous system development and function, ...

  3. Assessment of Risk Due to Chemicals Transferred in a Watershed: A Case of an Aquifer Storage Transfer and Recovery Site

    Directory of Open Access Journals (Sweden)

    Hyon Wook Ji

    2016-06-01

    Full Text Available This paper presents an analysis of the potential risks of chemicals that can affect an aquifer storage transfer and recovery (ASTR site. ASTR is a water supply system that injects surface water into an aquifer and then extracts naturally filtered groundwater. The pilot site of the ASTR supplying drinking water is located downstream of the Nakdong River in South Korea. Hazard analysis and critical control points (HACCP was adopted to ensure suitable water quality in response to the deteriorated water quality of the Nakdong River. HACCP is a proactive management system for ensuring consistent confidence in food (or water. Hazard analysis, the first of the seven principles of HACCP, assesses physical, microbial, chemical, and radioactive hazards. This study focuses on the chemicals that are most likely to be involved in major hazardous events. Pollutant release and transfer register (PRTR data were used to analyze potential risks of chemicals. A PRTR is a national environmental database of potentially hazardous chemicals. Potential risk analysis considers the total amount of chemicals transferred off-site for treatment or disposal. Fifty-five cities and the top 10 chemicals released in the Nakdong River basin were investigated. Potential risk was defined as a function of total transfers, the relative distance, and toxicity. The top 10 cities with high potential risks were identified, and the city with the highest potential risk turned out to be Ulju.

  4. Testing REACH draft technical guidance notes for conducting chemical safety assessments-the experience of a downstream user of a preparation.

    Science.gov (United States)

    Gade, Anne Lill; Ovrebø, Steinar; Hylland, Ketil

    2008-07-01

    The goal of REACH is the safe use of chemicals. This study examines the efficiency and usefulness of two draft technical guidance notes in the REACH Interim Project 3.2-2 for the development of the chemical safety report and exposure scenarios. A case study was carried out for a paint system for protection of structural steel. The focuses of the study were risk assessment of preparations based on Derived No Effect Level (DNEL) and Predicted No Effect Concentrations (PNEC) and on effective and accurate communication in the supply chain. Exposure scenarios and generic descriptions of uses, risk management measures, and exposure determinants were developed. The study showed that communication formats, software tools, and guidelines for chemical risk assessment need further adjustment to preparations and real-life situations. Web platforms may simplify such communication. The downstream formulator needs basic substance data from the substance manufacturer during the pre-registration phase to develop exposure scenarios for preparations. Default values need to be communicated in the supply chain because these were critical for the derivation of applicable risk management demands. The current guidelines which rely on the available toxicological knowledge are insufficient to advise downstream users on how to develop exposure scenarios for preparations.

  5. Organic and nitrogen fertilization of soil under Syrah grapevine: effects on soil chemical properties and nitrate concentration.

    OpenAIRE

    Davi José Silva; Luís Henrique Bassoi; Marlon Gomes da Rocha; Alexsandro Oliveira da Silva; Magnus Dall’Igna Deon

    2016-01-01

    ABSTRACT Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments cons...

  6. Organic and Nitrogen Fertilization of Soil under ‘Syrah’ Grapevine: Effects on Soil Chemical Properties and Nitrate Concentration

    OpenAIRE

    Silva,Davi José; Bassoi,Luís Henrique; Rocha,Marlon Gomes da; Silva, Alexsandro Oliveira da [UNESP; Deon,Magnus Dall'Igna

    2016-01-01

    ABSTRACT Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments cons...

  7. Quality of life in chemical warfare survivors with ophthalmologic injuries: the first results form Iran Chemical Warfare Victims Health Assessment Study

    Directory of Open Access Journals (Sweden)

    Soroush Mohammad

    2009-01-01

    Full Text Available Abstract Background Iraq used chemical weapons extensively against the Iranians during the Iran-Iraq war (1980–1988. The aim of this study was to assess the health related quality of life (HRQOL in people who had ophthalmologic complications due to the sulfur mustard gas exposure during the war. Methods The Veterans and Martyrs Affair Foundation (VMAF database indicated that there were 196 patients with severe ophthalmologic complications due to chemical weapons exposure. Of these, those who gave consent (n = 147 entered into the study. Quality of life was measured using the 36-item Short Form Health Survey (SF-36 and scores were compared to those of the general public. In addition logistic regression analysis was performed to indicate variables that contribute to physical and mental health related quality of life. Results The mean age of the patients was 44.8 (SD = 8.7 ranging from 21 to 75 years. About one-third of the cases (n= 50 reported exposure to chemical weapons more than once. The mean exposure duration to sulfur mustard gas was 21.6 years (SD = 1.2. The lowest scores on the SF-36 subscales were found to be: the role physical and the general health. Quality of life in chemical warfare victims who had ophthalmologic problems was significantly lower than the general public (P Conclusion The study findings suggest that chemical warfare victims with ophthalmologic complications suffer from poor health related quality of life. It seems that the need for provision of health and support for this population is urgent. In addition, further research is necessary to measure health related quality of life in victims with different types of disabilities in order to support and enhance quality of life among this population.

  8. The pretreatment effect of chemical skin penetration enhancers in transdermal drug delivery using iontophoresis.

    Science.gov (United States)

    Choi, E H; Lee, S H; Ahn, S K; Hwang, S M

    1999-01-01

    The transdermal drug delivery (TDD) system has largely been divided into physical, biochemical and chemical methods. Recently, combinations of these methods were introduced for more effective delivery with less side effects. We performed this study to identify the effectiveness and mechanism of TDD using the physical method, 'iontophoresis', plus the chemical method, 'pretreatment with chemical enhancer'. The action sites of chemical enhancers in the stratum corneum (SC) were observed by electron microscope. We also studied whether this combined method synergistically impaired the skin barrier. To confirm the synergistic effect on skin penetration by this combined method, we measured the blood glucose level after insulin iontophoresis following a chemical enhancer pretreatment in rabbits. The results were that (1) dilatation of the intercellular lipid layers of the SC and lacunae was prominent in pretreatment with chemical enhancers inducing high transepidermal water loss (TEWL); (2) the skin barrier impairment, with repeated treatments showing an increased TEWL and also epidermal proliferation, was increased with the chemical enhancers that showed a high TEWL immediately after treatment; (3) the combination of chemical enhancer pretreatment and iontophoresis showed no synergistic impairment of the skin barrier, and (4) the chemical enhancer pretreatment with greater impairment of the skin barrier could increase the delivery of insulin by iontophoresis. The results showed that a combination of chemical enhancer pretreatment and iontophoresis could deliver drugs more effectively than iontophoresis alone. Our proposed theory is that iontophoretic drug delivery may be easier through the dilated intercellular spaces of the SC which have a lower electrical impedance following the chemical enhancer pretreatment. Because the effect and the side effects in the combination are decided by the chemical enhancer rather than iontophoresis, the development of proper chemical

  9. Establishment of the first humpback whale fibroblast cell lines and their application in chemical risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Burkard, Michael, E-mail: Michael.burkard@eawag.ch [Griffith University, Environmental Futures Research Institute, Southern Ocean Persistent Organic Pollutants Program, Brisbane, QLD (Australia); Eawag, Swiss Federal Institute of Technology, Dübendorf (Switzerland); Whitworth, Deanne [The University of Queensland, School of Veterinary Science, Gatton, QLD (Australia); Schirmer, Kristin [Eawag, Swiss Federal Institute of Technology, Dübendorf (Switzerland); ETH Zürich, Institute of Biogechemistry and Pollutant Dynamics, Zürich (Switzerland); EPF Lausanne, School of Architecture, Civil and Environmental Engineering, Lausanne (Switzerland); Nash, Susan Bengtson [Griffith University, Environmental Futures Research Institute, Southern Ocean Persistent Organic Pollutants Program, Brisbane, QLD (Australia)

    2015-10-15

    Highlights: • We established and characterised the first humpback whale fibroblast cell lines. • Cell lines have a stable karyotype with 2n = 44. • Exposure to p,p′-DDE resulted in a concentration-dependent loss of cell viability. • p,p′-DDE sensitivity differed considerably from human fibroblasts. • Exposure to a whale blubber extract showed higher sensitivity than to p,p′-DDE alone. - Abstract: This paper reports the first successful derivation and characterization of humpback whale fibroblast cell lines. Primary fibroblasts were isolated from the dermal connective tissue of skin biopsies, cultured at 37 °C and 5% CO{sub 2} in the standard mammalian medium DMEM/F12 supplemented with 10% fetal bovine serum (FBS). Of nine initial biopsies, two cell lines were established from two different animals and designated HuWa1 and HuWa2. The cells have a stable karyotype with 2n = 44, which has commonly been observed in other baleen whale species. Cells were verified as being fibroblasts based on their spindle-shaped morphology, adherence to plastic and positive immunoreaction to vimentin. Population doubling time was determined to be ∼41 h and cells were successfully cryopreserved and thawed. To date, HuWa1 cells have been propagated 30 times. Cells proliferate at the tested temperatures, 30, 33.5 and 37 °C, but show the highest rate of proliferation at 37 °C. Short-term exposure to para,para′-dichlorodiphenyldichloroethylene (p,p′-DDE), a priority compound accumulating in southern hemisphere humpback whales, resulted in a concentration-dependent loss of cell viability. The effective concentration which caused a 50% reduction in HuWa1 cell viability (EC{sub 50} value) was approximately six times greater than the EC{sub 50} value for the same chemical measured with human dermal fibroblasts. HuWa1 exposed to a natural, p,p′-DDE-containing, chemical mixture extracted from whale blubber showed distinctively higher sensitivity than to p,p′-DDE alone

  10. Physical and chemical assessment of MSF distillate and SWRO product for drinking purpose

    KAUST Repository

    Gacem, Yasmine

    2012-03-01

    The objective of this study was to evaluate the physical and chemical proprieties of desalinated seawater produced by Multi Stage Flash (MSF) and Reverse Osmosis (RO) processes for drinking purpose. The final products, after post-treatment and blending, of Kahrama MSF and Bousfer SWRO plants located in different sites were investigated in this study. Different samples were taken from raw water and product before and after post-treatments in both plants. The physical and chemical balance revealed that the desalinated water produced by MSF plant is of better quality than that produced by the SWRO plant. The Langelier Saturation Index (LSI) was used as an indicator of the aggressiveness and corrosiveness of potable water. Indeed, the LSI of the distillate was slightly positive with over 77% of the values ranging from 0 to 0.13 while about 23% of the values were negative. This is due to the increase of MSF product water temperature from 29 °C to 33.82 °C during the investigation period and the calcium levels which decreased to a minimum value of 45.95. mg/l. On the other hand, the SWRO desalinated water had a negative LSI with values ranging from -3.27 to -1.85. These results are not within the recommended LSI values (between 0 and 0.4), which means that the product is highly aggressive and becomes improper for human consumption. These negative values are directly related to the RO product water temperature below 24.6 °C and calcium concentration below 16.03. mg/l as well as the lack of proper post-treatment process. From this investigation, it was recommended to improve the RO product post-treatment to make the remineralization process more effective. Some recommended guidelines suggested by the authors were presented in this paper. © 2012 Elsevier B.V.

  11. Effect of chemical degradation followed by toothbrushing on the surface roughness of restorative composites

    Directory of Open Access Journals (Sweden)

    Fernanda Regina Voltarelli

    2010-12-01

    Full Text Available OBJECTIVES: The aim of the present study was to assess the effect of the exposure to food-simulating liquids prior to brushing simulation on the surface roughness of five composite materials (Quixfil, Filtek Supreme, Esthet-X, Filtek Z250, Tetric Ceram. Material and METHODS: Twenty cylinders (5 mm diameter and 4 mm height of each composite were randomly allocated to 4 groups (n=5, according to the food-simulating liquid in which they were immersed for 7 days at 37°C: artificial saliva, heptane, citric acid, and ethanol. After this period, the top surface of composite cylinders was submitted to 7,500 brushing cycles (200 g load. Measurements of the surface roughness (Ra, ¼m were carried out before and after the exposure to the chemicals/brushing simulation. Changes on the morphology of composite surfaces were observed through scanning electron microscopy (SEM. RESULTS: The statistical analysis (ANOVA with cofactor / Tukey's test, α=5% detected a significant interaction between solutions and composite resins. Esthet-X, Filtek Z250 and Tetric Ceram were not affected by the food-simulating liquids/toothbrushing. Citric acid and ethanol increased the surface roughness of Quixfil and Filtek Supreme, respectively. SEM images corroborate the surface roughness findings, demonstrating the negative effect from chemical solutions and mechanical abrasion. CONCLUSIONS: The surface roughness of composite resin materials are differently affected by the food-simulating solutions, depending on the immersion media.

  12. Biological effects of activation products and other chemicals released from fusion power plants

    Energy Technology Data Exchange (ETDEWEB)

    Strand, J.A.; Poston, T.M.

    1976-09-01

    Literature reviews indicate that existing information is incomplete, often contradictory, and of questionable value for the prediction and assessment of ultimate impact from fusion-associated activation products and other chemical releases. It is still uncertain which structural materials will be used in the blanket and first wall of fusion power plants. However, niobium, vanadium, vanadium-chromium alloy, vanadium-titanium alloy, sintered aluminum product, and stainless steel have been suggested. The activation products of principal concern will be the longer-lived isotopes of /sup 26/Al, /sup 49/V, /sup 51/Cr, /sup 54/Mn, /sup 55/Fe, /sup 58/Co, /sup 60/Co, /sup 93/Nb, and /sup 94/Nb. Lithium released to the environment either during the mining cycle, from power plant operation or accident, may be in the form of a number of compound types varying in solubility and affinity for biological organisms. The effects of a severe liquid metal fire or explosion involving Na or K will vary according to inherent abiotic and biotic features of the affected site. Saline, saline-alkaline, and sodic soils of arid lands would be particularly susceptible to alkaline stress. Beryllium released to the environment during the mining cycle or reactor accident situation could be in the form of a number of compound types. Adverse effects to aquatic species from routine chemical releases (biocides, corrosion inhibitors, dissolution products) may occur in the discharge of both fission and fusion power plant designs.

  13. Physico-chemical assessment of paper mill effluent and its heavy metal remediation using aquatic macrophytes--a case study at JK Paper mill, Rayagada, India.

    Science.gov (United States)

    Mishra, Swayamprabha; Mohanty, Monalisa; Pradhan, Chinmay; Patra, Hemanta Kumar; Das, Ritarani; Sahoo, Santilata

    2013-05-01

    The present investigation aims to assess the phytoremediation potential of six aquatic macrophytes, viz. Eichhornia crassipes, Hydrilla verticillata, Jussiaea repens, Lemna minor, Pistia stratiotes and Trapa natans grown in paper mill effluent of JK Paper mill of Rayagada, Orissa, for remediation of heavy metals. The experiment was designed in pot culture experiments. Assessment of physico-chemical parameters of paper mill effluent showed significant decrease in pH, conductivity, total dissolved solids, total suspended solids, chlorine, sulphur, biological and chemical oxygen demand after growth of macrophytes for 20 days. Phytoremediation ability of these aquatic macrophytic species for copper (Cu) and mercury (Hg) was indicated by assessing the decrease in the levels of heavy metals from effluent water. Maximum reduction (66.5 %) in Hg content of untreated paper mill effluent was observed using L. minor followed by T. natans (64.8 %). L. minor showed highest reduction (71.4 %) of Cu content from effluent water followed by E. crassipes (63.6 %). Phytoextraction potential of L. minor was remarkable for Hg and Cu, and bioaccumulation was evident from bioconcentration factor values, i.e. 0.59 and 0.70, respectively. The present phytoremediation approach was considered more effective than conventional chemical treatment method for removing toxic contaminants from paper mill effluent.

  14. Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking.

    Science.gov (United States)

    Zou, Hongyan; Radke, Michael; Kierkegaard, Amelie; McLachlan, Michael S

    2015-08-18

    Chemical benchmarking was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence.

  15. Chemical, Thermal and Spectroscopic Methods to Assess Biodegradation of Winery-Distillery Wastes during Composting.

    Directory of Open Access Journals (Sweden)

    A Torres-Climent

    Full Text Available The objective of this work was to study the co-composting process of wastes from the winery and distillery industry with animal manures, using the classical chemical methods traditionally used in composting studies together with advanced instrumental methods (thermal analysis, FT-IR and CPMAS 13C NMR techniques, to evaluate the development of the process and the quality of the end-products obtained. For this, three piles were elaborated by the turning composting system, using as raw materials winery-distillery wastes (grape marc and exhausted grape marc and animal manures (cattle manure and poultry manure. The classical analytical methods showed a suitable development of the process in all the piles, but these techniques were ineffective to study the humification process during the composting of this type of materials. However, their combination with the advanced instrumental techniques clearly provided more information regarding the turnover of the organic matter pools during the composting process of these materials. Thermal analysis allowed to estimate the degradability of the remaining material and to assess qualitatively the rate of OM stabilization and recalcitrant C in the compost samples, based on the energy required to achieve the same mass losses. FT-IR spectra mainly showed variations between piles and time of sampling in the bands associated to complex organic compounds (mainly at 1420 and 1540 cm-1 and to nitrate and inorganic components (at 875 and 1384 cm-1, respectively, indicating composted material stability and maturity; while CPMAS 13C NMR provided semi-quantitatively partition of C compounds and structures during the process, being especially interesting their variation to evaluate the biotransformation of each C pool, especially in the comparison of recalcitrant C vs labile C pools, such as Alkyl /O-Alkyl ratio.

  16. Chemical, Thermal and Spectroscopic Methods to Assess Biodegradation of Winery-Distillery Wastes during Composting.

    Science.gov (United States)

    Torres-Climent, A; Gomis, P; Martín-Mata, J; Bustamante, M A; Marhuenda-Egea, F C; Pérez-Murcia, M D; Pérez-Espinosa, A; Paredes, C; Moral, R

    2015-01-01

    The objective of this work was to study the co-composting process of wastes from the winery and distillery industry with animal manures, using the classical chemical methods traditionally used in composting studies together with advanced instrumental methods (thermal analysis, FT-IR and CPMAS 13C NMR techniques), to evaluate the development of the process and the quality of the end-products obtained. For this, three piles were elaborated by the turning composting system, using as raw materials winery-distillery wastes (grape marc and exhausted grape marc) and animal manures (cattle manure and poultry manure). The classical analytical methods showed a suitable development of the process in all the piles, but these techniques were ineffective to study the humification process during the composting of this type of materials. However, their combination with the advanced instrumental techniques clearly provided more information regarding the turnover of the organic matter pools during the composting process of these materials. Thermal analysis allowed to estimate the degradability of the remaining material and to assess qualitatively the rate of OM stabilization and recalcitrant C in the compost samples, based on the energy required to achieve the same mass losses. FT-IR spectra mainly showed variations between piles and time of sampling in the bands associated to complex organic compounds (mainly at 1420 and 1540 cm-1) and to nitrate and inorganic components (at 875 and 1384 cm-1, respectively), indicating composted material stability and maturity; while CPMAS 13C NMR provided semi-quantitatively partition of C compounds and structures during the process, being especially interesting their variation to evaluate the biotransformation of each C pool, especially in the comparison of recalcitrant C vs labile C pools, such as Alkyl /O-Alkyl ratio.

  17. Exposure Assessment to Environmental Chemicals in Children from Ciudad Juarez, Chihuahua, Mexico.

    Science.gov (United States)

    Ochoa-Martinez, Angeles C; Orta-Garcia, Sandra T; Rico-Escobar, Edna M; Carrizales-Yañez, Leticia; Del Campo, Jorge D Martin; Pruneda-Alvarez, Lucia G; Ruiz-Vera, Tania; Gonzalez-Palomo, Ana K; Piña-Lopez, Iris G; Torres-Dosal, Arturo; Pérez-Maldonado, Ivan N

    2016-05-01

    It has been demonstrated that the human biomonitoring of susceptible populations is a valuable method for the identification of critical contaminants. Therefore, the purpose of this study was to assess the exposure profile for arsenic (As), lead (Pb), mercury (Hg), 1-hydroxypyrene (1-OHP), 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in children living in Ciudad Juarez, Chihuahua, Mexico (a major manufacturing center in Mexico). In 2012, we evaluated a total of 135 healthy children living in Ciudad Juarez since birth. The total PBDEs levels ranged from nondetectable (< LOD) to 215 ng/g lipid, with a mean total PBDEs level of 29.5 ± 53.0 ng/g lipid (geometric mean ± standard deviation). The mean total PCBs level in the study participants was 29.0 ± 10.5 ng/g lipid (range 4.50-50.0 ng/g lipid). The mean concentration of total DDT (DDT + DDE) was 11.9 ± 6.70 ng/g lipid (range 3.00-26.0 ng/g lipid). The mean 1-OHP levels was 1.2 ± 1.1 µmol/mol creatinine (range chemicals analyzed in the children living in the study community. Therefore, a biomonitoring program for the surveillance of the child population in Ciudad Juarez is necessary.

  18. Non-equilibrium effects in high temperature chemical reactions

    Science.gov (United States)

    Johnson, Richard E.

    1987-01-01

    Reaction rate data were collected for chemical reactions occurring at high temperatures during reentry of space vehicles. The principle of detailed balancing is used in modeling kinetics of chemical reactions at high temperatures. Although this principle does not hold for certain transient or incubation times in the initial phase of the reaction, it does seem to be valid for the rates of internal energy transitions that occur within molecules and atoms. That is, for every rate of transition within the internal energy states of atoms or molecules, there is an inverse rate that is related through an equilibrium expression involving the energy difference of the transition.

  19. Effects of toxic metals and chemicals on biofilm and biocorrosion.

    Science.gov (United States)

    Fang, Herbert H P; Xu, Li-Chong; Chan, Kwong-Yu

    2002-11-01

    Microbes in marine biofilms aggregated into clusters and increased the production of extracellular polymeric substances (EPS), by over 100% in some cases, when the seawater media containing toxic metals and chemicals, such as Cd(II), Cu(II), Pb(II), Zn(II), AI(III), Cr(III), glutaraldehyde, and phenol. The formation of microbial cluster and the increased production of EPS, which contained 84-92% proteins and 8-16% polysaccharides, accelerated the corrosion of the mild steel. However, there was no quantitative relationship between the degree of increased corrosion and the toxicity of metals/chemicals towards sulfate-reducing bacteria, or the increased EPS production.

  20. Multiple stressor effects in Chlamydomonas reinhardtii – Toward understanding mechanisms of interaction between effects of ultraviolet radiation and chemical pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Korkaric, Muris [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600, Duebendorf (Switzerland); ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich (Switzerland); Behra, Renata; Fischer, Beat B. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600, Duebendorf (Switzerland); Junghans, Marion [Swiss Center for Applied Ecotoxicology Eawag-EPFL, 8600, Duebendorf (Switzerland); Eggen, Rik I.L., E-mail: rik.eggen@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600, Duebendorf (Switzerland); ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich (Switzerland)

    2015-05-15

    Highlights: • Systematic study of multiple stressor effects of UVR and chemicals in C. reinhardtii. • UVR and chemicals did not act independently on algal photosynthesis and reproduction. • Multiple stressor effects of UVR and chemicals depended on chemical MOA. • Synergistic effect interactions not limited to oxidative stress inducing chemicals. • Multiple MOAs of UVR may limit applicability of current prediction models. - Abstract: The effects of chemical pollutants and environmental stressors, such as ultraviolet radiation (UVR), can interact when organisms are simultaneously exposed, resulting in higher (synergistic) or lower (antagonistic) multiple stressor effects than expected based on the effects of single stressors. Current understanding of interactive effects is limited due to a lack of mechanism-based multiple stressor studies. It has been hypothesized that effect interactions may generally occur if chemical and non-chemical stressors cause similar physiological effects in the organism. To test this hypothesis, we exposed the model green alga Chlamydomonas reinhardtii to combinations of UVR and single chemicals displaying modes of action (MOA) similar or dissimilar to the impact of UVR on photosynthesis. Stressor interactions were analyzed based on the independent action model. Effect interactions were found to depend on the MOA of the chemicals, and also on their concentrations, the exposure time and the measured endpoint. Indeed, only chemicals assumed to cause effects on photosynthesis similar to UVR showed interactions with UVR on photosynthetic yield: synergistic in case of Cd(II) and paraquat and antagonistic in case of diuron. No interaction on photosynthesis was observed for S-metolachlor, which acts dissimilarly to UVR. However, combined effects of S-metolachlor and UVR on algal reproduction were synergistic, highlighting the importance of considering additional MOA of UVR. Possible mechanisms of stressor effect interactions are

  1. Toxicity tests with crustaceans for detecting sublethal effects of potential endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Wollenberger, Leah

    /antagonistic activity with the ecdysteroid-responsive Drosophila melanogaster BII cell line 6) to draft an OECD guideline proposal for testing of chemicals based on the experimental work performed within this study In preliminary investigations with A. tonsa were studied various parameters related to processes...... regulated by hormones such as growth, molting, sexual maturation and reproduction. The primary endpoints were larval development ratio, egg production and sex ratio. Exposure experiments were conducted with naturally occurring and synthetic vertebrate and invertebrate hormones as well as compounds known...... contribution of the present work with BFRs was to establish data on their (sub)chronic toxicity towards marine copepods. To discriminate between general toxicological and endocrine-mediated toxic effects, the model compounds were assessed in vitro for ecdysteroid agonistic/antagonistic activity using...

  2. Application of Biomonitoring in Risk Assessment of Chemical Hazards%生物监测任化学危害物风险评估中的应用

    Institute of Scientific and Technical Information of China (English)

    吴春峰; Richard A.KREUTZER; 刘弘

    2011-01-01

    Risk assessment was widely used as a scientific tool around the world to evaluate the probability of human health effects resulting from chemical hazards exposure. However, limited resources increased the uncertainties in most risk assessments such as lack of human exposure and dose data. Biomonitoring was a direct way to provide human data on internal exposure and early effects for a more precise and realistic risk assessment. Many developed countries and international institutes had established biomonitoring progtams and encourage applying biomonitoring data in the risk assessment process. This article addressed the definition and development of biomonitoring, depicts the use of biomonitoring in chemical risk assessment and exposure assessment,illustrates the interpretation of biomonitoring data for risk assessment, and illuminates the limitations of integration of biomonitoring data in risk assessment. In conclusion, biomonitoring has the potential to greatly improve chemical risk assessment with the accumulation of relevant data.%风险评估,是目前国际上推崇的评估暴露于环境化学危害物导致不良人体健康效应概率的科学方法,己在世界各国广泛使用.然而,在大部分的风险评估中,因缺乏人群暴露和剂量的数据而增加了评估的不确定性.生物监测能提高风险评估的准确性和真实性,直接提供人体内暴露和早期效应的信息.目前,许多国际组织和发达国家已建立生物监测项目,并鼓励将生物监测数据应用干风险评估之中.本文将阐述生物监测的定义和发展,详细描述化学危害物风险评估和暴露评估中生物监测的作用,举例说明风险评估中生物监测数据的解释,以及整合生物监测的局限性.总之,随着各类数据的积累,生物监测有能力使化学危害物风险评估更完善.

  3. Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl (Athene cunicularia hypugaea) as a case study

    Science.gov (United States)

    Engelman, Catherine A.; Grant, William E.; Mora, Miguel A.; Woodin, Marc

    2012-01-01

    We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls (Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove

  4. Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl (Athene cunicularia hypugaea) as a case study

    Science.gov (United States)

    Engelman, C.A.; Grant, W.E.; Mora, M.A.; Woodin, M.

    2012-01-01

    We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls (Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove

  5. Application of a framework for extrapolating chemical effects across species in pathways controlled by estrogen receptor-á

    Science.gov (United States)

    Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetic...

  6. Assessment of the Low Alloy Cast Steel Inoculation Effects with Chosen Additives

    Directory of Open Access Journals (Sweden)

    D. Bartocha

    2012-04-01

    Full Text Available Structure, and thus the mechanical properties of steel are primarily a function of chemical composition and the solidification process which can be influenced by the application of the inoculation treatment. This effect depends on the modifier used. The article presents the results of studies designed to assess the effects of structural low alloy steel inoculation by selected modifying additives. The study was performed on nine casts modeled with different inoculants, assessment of the procedure impact was based on the macrostructure of made castings. The ratio of surface area equivalent to the axial zone of the crystals and columnar crystals zone was adopted as a measure of the inoculation effect.

  7. Perfluorononanoic acid in combination with 14 chemicals exerts low-dose mixture effects in rats

    DEFF Research Database (Denmark)

    Hadrup, Niels; Pedersen, Mikael; Skov, Kasper;

    2016-01-01

    Humans are simultaneously exposed to several chemicals that act jointly to induce mixture effects. At doses close to or higher than no-observed adverse effect levels, chemicals usually act additively in experimental studies. However, we are lacking knowledge on the importance of exposure to compl...

  8. Effect of conventional chemical treatment on the microbial

    NARCIS (Netherlands)

    Bereschenko, L.A.; Prummel, H.; Euverink, G.J.W.; Stams, A.J.M.; Loosdrecht, M.C.M. van

    2011-01-01

    The impact of conventional chemical treatment on initiation and spatiotemporal development of biofilms on reverse osmosis (RO) membranes was investigated in situ using flow cells placed in parallel with the RO system of a full-scale water treatment plant. The flow cells got the same feed (extensivel

  9. Sample preparation for combined chemical analysis and bioassay application in water quality assessment

    NARCIS (Netherlands)

    Kolkman, A.; Schriks, M.; Brand, W; Bäuerlein, P.S.; van der Kooi, M.M.E.; van Doorn, R.H.; Emke, E.; Reus, A.; van der Linden, S.; de Voogt, P.; Heringa, M.B.

    2013-01-01

    The combination of in vitro bioassays and chemical screening can provide a powerful toolbox to determine biologically relevant compounds in water extracts. In this study, a sample preparation method is evaluated for the suitability for both chemical analysis and in vitro bioassays. A set of 39 chemi

  10. Sustainability assessment of novel chemical processes at early stage: application to biobased processes

    NARCIS (Netherlands)

    Patel, A.D.; Meesters, K.; Uil, H. den; Jong, E. de; Blok, K.; Patel, M.K.

    2012-01-01

    Chemical conversions have been a cornerstone of industrial revolution and societal progress. Continuing this progress in a resource constrained world poses a critical challenge which demands the development of innovative chemical processes to meet our energy and material needs in a sustainable way.

  11. Numerical modeling of chemical spills and assessment of their environmental impacts

    Science.gov (United States)

    Chemical spills in surface water bodies often occur in modern societies, which cause significant impacts on water quality, eco-environment and drinking water safety. In this paper, chemical spill contamination in water resources was studied using a depth-integrated computational model, CCHE2D, for p...

  12. A quantitative screening-level approach to incorporate chemical exposure and risk/safety into alternative assessment evaluations.

    Science.gov (United States)

    Arnold, Scott M; Greggs, Bill; Goyak, Katy O; Landenberger, Bryce D; Mason, Ann M; Howard, Brett; Zaleski, Rosemary; Howard, Brett; Zaleski, Rosemary T

    2017-03-10

    As the general public and retailers ask for disclosure of chemical ingredients in the marketplace, a number of hazard screening tools were developed to evaluate the so called "greenness" of individual chemical ingredients and/or formulations. The majority of these tools focus only on hazard, often using chemical lists, ignoring the other part of the risk equation: exposure. Using a hazard-only focus can result in regrettable substitutions, changing one chemical ingredient for another that turns out to be more hazardous or shifts the toxicity burden to others. To minimize the incidents of regrettable substitutions, BizNGO describes 'Common Principles' to frame a process for informed substitution. Two of the six principles state reduce hazard and minimize exposure. A number of frameworks have emerged to evaluate and assess alternatives. One framework developed by leading experts under the auspices of the U.S. National Academy of Sciences recommended that hazard and exposure be specifically addressed in the same step when assessing candidate alternatives. For the alternative assessment community, this paper serves as an informational resource for considering exposure in an alternatives assessment using elements of problem formulation; product identity, use, and composition; hazard analysis; exposure analysis; and risk characterization. These conceptual elements build upon practices from government, academia, and industry and are exemplified through two hypothetical case studies demonstrating the questions asked and decisions faced in new product development. These two case studies - inhalation exposure to a generic paint product and environmental exposure to a shampoo rinsed down the drain - demonstrate the criteria, considerations, and methods required to combine exposure models addressing human health and environmental impacts to provide a screening level hazard/exposure (risk) analysis. This paper informs practices for these elements within a comparative risk

  13. Assessing the Higher National Diploma Chemical Engineering programme in Ghana: students' perspective

    Science.gov (United States)

    Boateng, Cyril D.; Cudjoe Bensah, Edem; Ahiekpor, Julius C.

    2012-05-01

    Chemical engineers have played key roles in the growth of the chemical and allied industries in Ghana but indigenous industries that have traditionally been the domain of the informal sector need to be migrated to the formal sector through the entrepreneurship and innovation of chemical engineers. The Higher National Diploma Chemical Engineering programme is being migrated from a subject-based to a competency-based curriculum. This paper evaluates the programme from the point of view of students. Data were drawn from a survey conducted in the department and were analysed using SPSS. The survey involved administering questionnaires to students at all levels in the department. Analysis of the responses indicated that the majority of the students had decided to pursue chemical engineering due to the career opportunities available. Their knowledge of the programme learning outcomes was, however, poor. The study revealed that none of the students was interested in developing indigenous industries.

  14. Analysis of current research addressing complementary use of life-cycle assessment and risk assessment for engineered nanomaterials: have lessons been learned from previous experience with chemicals?

    DEFF Research Database (Denmark)

    Grieger, Khara Deanne; Laurent, Alexis; Miseljic, Mirko

    2012-01-01

    While it is generally agreed that successful strategies to address the health and environmental impacts of engineered nanomaterials (NM) should consider the well-established frameworks for conducting life-cycle assessment (LCA) and risk assessment (RA), scientific research, and specific guidance...... on how to practically apply these methods are still very much under development. This paper evaluates how research efforts have applied LCA and RA together for NM, particularly reflecting on previous experiences with applying these methods to chemicals. Through a literature review and a separate analysis...... of research focused on applying LCA and RA together for NM, it appears that current research efforts have taken into account some key ‘‘lessons learned’’ from previous experience with chemicals while many key challenges remain for practically applying these methods to NM. We identified two main approaches...

  15. Assessing the distribution of volatile organic compounds using land use regression in Sarnia, "Chemical Valley", Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Luginaah Isaac N

    2009-04-01

    Full Text Available Abstract Background Land use regression (LUR modelling is proposed as a promising approach to meet some of the challenges of assessing the intra-urban spatial variability of ambient air pollutants in urban and industrial settings. However, most of the LUR models to date have focused on nitrogen oxides and particulate matter. This study aimed at developing LUR models to predict BTEX (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene concentrations in Sarnia, 'Chemical Valley', Ontario, and model the intra-urban variability of BTEX compounds in the city for a community health study. Method Using Organic Vapour Monitors, pollutants were monitored at 39 locations across the city of Sarnia for 2 weeks in October 2005. LUR models were developed to generate predictor variables that best estimate BTEX concentrations. Results Industrial area, dwelling counts, and highways adequately explained most of the variability of BTEX concentrations (R2: 0.78 – 0.81. Correlations between measured BTEX compounds were high (> 0.75. Although most of the predictor variables (e.g. land use were similar in all the models, their individual contributions to the models were different. Conclusion Yielding potentially different health effects than nitrogen oxides and particulate matter, modelling other air pollutants is essential for a better understanding of the link between air pollution and health. The LUR models developed in these analyses will be used for estimating outdoor exposure to BTEX for a larger community health study aimed at examining the determinants of health in Sarnia.

  16. Managing the effects of endocrine disrupting chemicals in wastewater-impacted streams

    Science.gov (United States)

    Bradley, Paul M.; Kolpin, Dana W.

    2013-01-01

    A revolution in analytical instrumentation circa 1920 greatly improved the ability to characterize chemical substances. This analytical foundation resulted in an unprecedented explosion in the design and production of synthetic chemicals during and post-World War II. What is now often referred to as the 2nd Chemical Revolution has provided substantial societal benefits; with modern chemical design and manufacturing supporting dramatic advances in medicine, increased food production, and expanding gross domestic products at the national and global scales as well as improved health, longevity, and lifestyle convenience at the individual scale. Presently, the chemical industry is the largest manufacturing sector in the United States (U.S.) and the second largest in Europe and Japan, representing approximately 5% of the Gross Domestic Product (GDP) in each of these countries. At the turn of the 21st century, the chemical industry was estimated to be worth more than $1.6 trillion and to employ over 10 million people, globally. During the first half of the 20th century, the chemical sector expanded rapidly, the chemical industry enjoyed a generally positive status in society, and chemicals were widely appreciated as fundamental to individual and societal quality of life. Starting in the 1960s, however, the environmental costs associated with the chemical industry increasingly became the focus, due in part to the impact of books like “Silent Spring” and “Our Stolen Future” and to a number of highly publicized environmental disasters. Galvanizing chemical industry disasters included the 1976 dioxin leak north of Milan, Italy, the Love Canal evacuations in Niagara, New York beginning in 1978, and the Union Carbide leak in Bhopal, India in 1984. Understanding the environmental impact of synthetic compounds is essential to any informed assessment of net societal benefit, for the simple reason that any chemical substance that is in commercial production or use will

  17. Effect of Chemical Corrosion on the Mechanical Characteristics of Parent Rocks for Nuclear Waste Storage

    Directory of Open Access Journals (Sweden)

    Tielin Han

    2016-01-01

    Full Text Available Long-term immersion was adopted to explore the damage deterioration and mechanical properties of granite under different chemical solutions. Here, granite was selected as the candidate of parent rocks for nuclear waste storage. The physical and mechanical properties of variation regularity immersed in various chemical solutions were analyzed. Meanwhile, the damage variable based on the variation in porosity was used in the quantitative analysis of chemical damage deterioration degree. Experimental results show that granite has a significant weakening tendency after chemical corrosion. The fracture toughness KIC, splitting tensile strength, and compressive strength all demonstrate the same deteriorating trend with chemical corrosion time. However, a difference exists in the deterioration degree of the mechanical parameters; that is, the deterioration degree of fracture toughness KIC is the greatest followed by those of splitting tensile strength and compressive strength, which are relatively smaller. Strong acid solutions may aggravate chemical damage deterioration in granite. By contrast, strong alkaline solutions have a certain inhibiting effect on chemical damage deterioration. The chemical solutions that feature various compositions may have different effects on chemical damage degree; that is, SO42- ions have a greater effect on the chemical damage in granite than HCO3- ions.

  18. Assessment of changes of some functions of Ukrainian acid soils after chemical amelioration

    Directory of Open Access Journals (Sweden)

    Zapko Yurij

    2014-09-01

    Full Text Available The objective of the article was to determine the effectiveness of lime of different origin for chemical amelioration of soils and examine its impact on soil functions such as productivity, habitat, regulation of water quality, and the protective buffer biogeocenotic screen. Limy ameliorants were applied in small local field experiment on Luvic Chernozem, and experiment with lysimeter columns was carried out on Albic Luvisol. The number of the main groups of microflora and enzymatic activity of soil was determined in soil samples taken for the analysis from the root zone. Research concerning the influence of natural and industrial origin ameliorants on soil as habitat showed the correlation of sugar beets productivity with soil biogenic. The increase of biomultiplicity of soil microbiota after addition of a cement dust and negative influence of red sludge on soil as habitat for living organisms was observed. Research involving the influence of ameliorants on soil by lime as the protective buffer biogeocenotic screen was carried out using lysimeter columns. It was stated that the addition of limy ameliorants reduces mobility of heavy metals.

  19. Chemical and bioanalytical assessments on drinking water treatments by quaternized magnetic microspheres.

    Science.gov (United States)

    Shi, Peng; Ma, Rong; Zhou, Qing; Li, Aimin; Wu, Bing; Miao, Yu; Chen, Xun; Zhang, Xuxiang

    2015-03-21

    This study aimed to compare the toxicity reduction performance of conventional drinking water treatment (CT) and a treatment (NT) with quaternized magnetic microspheres (NDMP) based on chemical analyses. Fluorescence excitation-emission-matrix combined with parallel factor analysis identified four components in source water of different rivers or lake, and the abundance of each component differed greatly among the different samples. Compared with the CT, the NT evidently reduced the concentrations of dissolved organic carbon, adsorbable organic halogens (AOX), bromide and disinfection by-products. Toxicological evaluation indicated that the NT completely eliminated the cytotoxicity, and greatly reduced the genotoxicity and oxidative stress of all raw water. In contrast, the CT increased the cytotoxicity of Taihu Lake and the Zhongshan River water, genotoxicity of Taihu Lake and the Mangshe River water, as well as the levels of superoxide dismutase and malondialdehyde of the Mangshe River water. Correlation analysis indicated that the AOX of the treated samples was significantly correlated with the genotoxicity and glutathione concentration, but exhibited no correlation with either of them for all the samples. As it can effectively reduce pollutant levels and the toxicities of drinking water, NDMP might be widely used for drinking water treatment in future.

  20. Assessment of Application Technology of Natural User Interfaces in the Creation of a Virtual Chemical Laboratory

    Science.gov (United States)

    Jagodziński, Piotr; Wolski, Robert

    2015-02-01

    Natural User Interfaces (NUI) are now widely used in electronic devices such as smartphones, tablets and gaming consoles. We have tried to apply this technology in the teaching of chemistry in middle school and high school. A virtual chemical laboratory was developed in which students can simulate the performance of laboratory activities similar to those that they perform in a real laboratory. Kinect sensor was used for the detection and analysis of the student's hand movements, which is an example of NUI. The studies conducted found the effectiveness of educational virtual laboratory. The extent to which the use of a teaching aid increased the students' progress in learning chemistry was examined. The results indicate that the use of NUI creates opportunities to both enhance and improve the quality of the chemistry education. Working in a virtual laboratory using the Kinect interface results in greater emotional involvement and an increased sense of self-efficacy in the laboratory work among students. As a consequence, students are getting higher marks and are more interested in the subject of chemistry.

  1. Chemical Reactivity Probes for Assessing Abiotic Natural Attenuation by Reducing Iron Minerals.

    Science.gov (United States)

    Fan, Dimin; Bradley, Miranda J; Hinkle, Adrian W; Johnson, Richard L; Tratnyek, Paul G

    2016-02-16

    Increasing recognition that abiotic natural attenuation (NA) of chlorinated solvents can be important has created demand for improved methods to characterize the redox properties of the aquifer materials that are responsible for abiotic NA. This study explores one promising approach: using chemical reactivity probes (CRPs) to characterize the thermodynamic and kinetic aspects of contaminant reduction by reducing iron minerals. Assays of thermodynamic CRPs were developed to determine the reduction potentials (ECRP) of suspended minerals by spectrophotometric determination of equilibrium CRP speciation and calculations using the Nernst equation. ECRP varied as expected with mineral type, mineral loading, and Fe(II) concentration. Comparison of ECRP with reduction potentials measured potentiometrically using a Pt electrode (EPt) showed that ECRP was 100-150 mV more negative than EPt. When EPt was measured with small additions of CRPs, the systematic difference between EPt and ECRP was eliminated, suggesting that these CRPs are effective mediators of electron transfer between mineral and electrode surfaces. Model contaminants (4-chloronitrobenzene, 2-chloroacetophenone, and carbon tetrachloride) were used as kinetic CRPs. The reduction rate constants of kinetic CRPs correlated well with the ECRP for mineral suspensions. Using the rate constants compiled from literature for contaminants and relative mineral reduction potentials based on ECRP measurements, qualitatively consistent trends were obtained, suggesting that CRP-based assays may be useful for estimating abiotic NA rates of contaminants in groundwater.

  2. Neuroendocrine and behavioral effects of embryonic exposure to endocrine disrupting chemicals in birds.

    Science.gov (United States)

    Ottinger, Mary Ann; Lavoie, Emma; Thompson, Nichola; Barton, Ashley; Whitehouse, Kasen; Barton, Meredith; Abdelnabi, Mahmoud; Quinn, Michael; Panzica, GianCarlo; Viglietti-Panzica, Carla

    2008-03-01

    Endocrine disrupting chemicals (EDCs) exert hormone-like activity in vertebrates and exposure to these compounds may induce both short- and long-term deleterious effects including functional alterations that contribute to decreased reproduction and fitness. An overview of the effects of a number of EDCs, including androgenic and estrogenic compounds, will be considered. Many studies have been conducted in the precocial Japanese quail, which provides an excellent avian model for testing these compounds. Long-term impacts have also been studied by raising a subset of animals through maturation. The EDCs examined included estradiol, androgen active compounds, soy phytoestrogens, and atrazine. Effects on behavior and hypothalamic neuroendocrine systems were examined. All EDCs impaired reproduction, regardless of potential mechanism of action. Male sexual behavior proved to be a sensitive index of EDC exposure and embryonic exposure to a variety of EDCs consistently resulted in impaired male sexual behavior. Several hypothalamic neural systems proved to be EDC responsive, including arginine vasotocin (VT), catecholamines, and gonadotropin releasing hormone system (GnRH-I). Finally, EDCs are known to impact both the immune and thyroid systems; these effects are significant for assessing the overall impact of EDCs on the fitness of avian populations. Therefore, exposure to EDCs during embryonic development has consequences beyond impaired function of the reproductive axis. In conclusion, behavioral alterations have the advantage of revealing both direct and indirect effects of exposure to an EDC and in some cases can provide a valuable clue into functional deficits at different physiological levels.

  3. Biological assessment for the remedial action at the chemical plant area of the Weldon Spring site

    Energy Technology Data Exchange (ETDEWEB)

    Hlohowskyj, I.; Dunn, C.P.

    1992-11-01

    The Weldon Spring site in St.Charles County, Missouri, became contaminated during the 1940s through the 1960s as a result of explosives production by the US Army and uranium and thorium processing by the predecessor agency of the US Department of Energy (DOE). The site is listed on the National Priorities List of the US Environmental Protection Agency, and DOE is responsible for its cleanup. Contaminants are present in soil, surface water, and aquatic sediments. Alternatives identified for site remediation are no action (included as baseline for comparison), treatment and disposal of the wastes at the Weldon Spring site, and on-site treatment followed by off-site disposal at either a commercial facility near Clive, Utah, or at DOE`s Hanford site near Richland, Washington. In accordance with the requirements of the Endangered Species Act, this biological assessment has been prepared to evaluate the potential effects of proposed remedial action alternatives on federal listed (endangered or threatened) and candidate species at the respective sites. The assessment includes consideration of the environmental setting at each site; the federal listed and candidate species that could occur at each site; the construction, excavation, and treatment activities under each alternative; and the amount of land area affected at each site.

  4. Biological assessment for the remedial action at the chemical plant area of the Weldon Spring site

    Energy Technology Data Exchange (ETDEWEB)

    Hlohowskyj, I.; Dunn, C.P.

    1992-11-01

    The Weldon Spring site in St.Charles County, Missouri, became contaminated during the 1940s through the 1960s as a result of explosives production by the US Army and uranium and thorium processing by the predecessor agency of the US Department of Energy (DOE). The site is listed on the National Priorities List of the US Environmental Protection Agency, and DOE is responsible for its cleanup. Contaminants are present in soil, surface water, and aquatic sediments. Alternatives identified for site remediation are no action (included as baseline for comparison), treatment and disposal of the wastes at the Weldon Spring site, and on-site treatment followed by off-site disposal at either a commercial facility near Clive, Utah, or at DOE's Hanford site near Richland, Washington. In accordance with the requirements of the Endangered Species Act, this biological assessment has been prepared to evaluate the potential effects of proposed remedial action alternatives on federal listed (endangered or threatened) and candidate species at the respective sites. The assessment includes consideration of the environmental setting at each site; the federal listed and candidate species that could occur at each site; the construction, excavation, and treatment activities under each alternative; and the amount of land area affected at each site.

  5. The effect of chemical admixtures and mineral additives on the properties of self-compacting mortars

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Sahmaran; Heru Ari Christianto; Ismail Ozgur Yaman [Middle East Technical University, Ankara (Turkey). Department of Civil Engineering

    2006-05-15

    Mortar serves as the basis for the workability properties of self-compacting concrete (SCC) and these properties could be assessed by self-compacting mortars (SCM). In fact, assessing the properties of SCM is an integral part of SCC design. The objective of this study was to evaluate the effectiveness of various mineral additives and chemical admixtures in producing SCMs. For this purpose, four mineral additives (fly ash, brick powder, limestone powder, and kaolinite), three superplasticizers (SP), and two viscosity modifying admixtures (VMA) were used. Within the scope of the experimental program, 43 mixtures of SCM were prepared keeping the amount of mixing water and total powder content (Portland cement and mineral additives) constant. Workability of the fresh mortar was determined using mini V-funnel and mini slump flow tests. The setting time of the mortars, were also determined. The hardened properties that were determined included ultrasonic pulse velocity and strength determined at 28 and 56 days. It was concluded that among the mineral additives used, fly ash and limestone powder significantly increased the workability of SC