Science.gov

Sample records for airborne contaminants assessment

  1. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT RESEARCH PLAN

    EPA Science Inventory

    The goal of the Western Airborne Contaminants Assessment Project (WACAP) is to assess the deposition of airborne contaminants in Western National Parks, providing regional and local information on exposure, accumulation, impacts, and probable sources. This project is being desig...

  2. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

    A method of estimation of inhalation exposure to airborne soil contaminants is presented. this method is derived from studies of airborne soil particles with radioactive tags. The concentration of contaminants in air (g/m{sup 3}) can be derived from the product of M, the suspended respirable dust mass concentration (g/m{sup 3}), S, the concentration of contaminant in the soil (g/g), and E{sub f}, an enhancement factor. Typical measurement methods and values of M, and E{sub f} are given along with highlights of experiences with this method.

  3. Approaches to airborne molecular contamination assessment

    NASA Astrophysics Data System (ADS)

    Riddle Vogt, Sarah; Landoni, Cristian

    2011-03-01

    Airborne molecular contamination (AMC) assessment approaches can vary greatly between different fabs and even between different divisions within a given company. Some companies have very rigorous testing schedules (such as those needed to maintain tool warranties) while others feel AMC testing is only necessary when they are having a problem. While choosing to only test for AMC when a trouble arises may be cost effective in the short term it can have significant impacts on tools, in particular tool optics, and product losses due to defects which can cost significantly more in the long term than the AMC testing would have. Another critical issue in assessing AMC is what species you should be testing for. Some volatile species may not cause an issue in your process while part-per-trillion volume (pptv) amounts of others can do serious damage to your tools and/or products. Knowledge of which volatile compounds can cause problems in your applications and at what levels is crucial in deciding what type of AMC assessment to perform and at what frequency. Typically four classes of AMC are routinely monitored in clean rooms and tool environments: acids, bases, hydrocarbons, and refractory compounds. Real world examples will be presented using the solely solid-state trap collection methods utilized by SAES Pure Gas.

  4. The Western Airborne Contaminant Assessment Project (WACAP): An interdisciplinary evaluation of the impacts of airborne contaminants in Western U.S. National Parks

    EPA Science Inventory

    The Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 by the National Park Service to determine if airborne contaminants were having an impact on remote western ecosystems. Multiple sample media (snow, water, sediment, fish and terrestrial vegetation...

  5. Modeling for Airborne Contamination

    SciTech Connect

    F.R. Faillace; Y. Yuan

    2000-08-31

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of sufficient thickness to simulate the drift

  6. Assessment of SRS radiological liquid and airborne contaminants and pathways

    SciTech Connect

    Jannik, G.T.

    1997-04-01

    This report compiles and documents the radiological critical-contaminant/critical-pathway analysis performed for SRS. The analysis covers radiological releases to the atmosphere and to surface water, which are the principal media that carry contaminants off site. During routine operations at SRS, limited amounts of radionuclides are released to the environment through atmospheric and/or liquid pathways. These releases potentially result in exposure to offsite people. Though the groundwater beneath an estimated 5 to 10 percent of SRS has been contaminated by radionuclides, there is no evidence that groundwater contaminated with these constituents has migrated offsite (Arnett, 1996). Therefore, with the notable exception of radiological source terms originating from shallow surface water migration into site streams, onsite groundwater was not considered as a potential exposure pathway to offsite people.

  7. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    PubMed

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments.

  8. Occupational Exposure Assessment of Airborne Chemical Contaminants Among Professional Ski Waxers

    PubMed Central

    Freberg, Baard Ingegerdsson; Olsen, Raymond; Daae, Hanne Line; Hersson, Merete; Thorud, Syvert; Ellingsen, Dag G.; Molander, Paal

    2014-01-01

    Background: Ski waxes are applied onto the skis to improve the performance. They contain different chemical substances, e.g. perfluoro-n-alkanes. Due to evaporation and sublimation processes as well as mechanically generated dust, vapours, fumes, and particulates can contaminate the workroom atmosphere. The number of professional ski waxers is increasing, but occupational exposure assessments among professional ski waxers are lacking. Objectives: The aim was to assess exposure to airborne chemical contaminants among professional ski waxers. It was also a goal to construct a ventilation system designed for ski waxing work operations. Methods: Forty-five professional ski waxers were included. Personal measurements of the inhalable and the respirable aerosol mass fractions were executed in 36 different waxing cabins using Conical Inhalable Sampler cassettes equipped with 37-mm PVC filters (5 µm) and Casella respirable cyclones equipped with 37-mm PVC filters (0.8 µm), respectively. Volatile organic components were collected using Anasorb CSC charcoal tubes. To examine time trends in exposure patterns, stationary real-time measurements of the aerosol mass fractions were conducted using a direct-reading Respicon® sampler. Results: Mean aerosol particle mass concentrations of 3.1 mg·m−3 (range: 0.2–12.0) and 6.2 mg·m−3 (range: 0.4–26.2) were measured in the respirable and inhalable aerosol mass fractions, respectively. Real-time aerosol sampling showed large variations in particle concentrations, with peak exposures of ~10 and 30 mg·m−3 in the respirable and the inhalable aerosol particle mass fractions, respectively. The custom-made ventilation system reduced the concentration of all aerosol mass fractions by more than 90%. PMID:24607772

  9. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT (WACAP): ASSESSING DEPOSITION AND IMPACTS OF PERSISTENT ORGANIC POLLUTANTS AND METALS IN SEVEN NATIONAL PARKS IN THE WESTERN UNITED STATES

    EPA Science Inventory

    Airborne contaminants, especially those that biomagnify in the food chain, can pose serious health threats to wildlife and humans. Biological effects of airborne contaminants include impacts on reproductive success, growth, behavior, disease, and survival. In response to concer...

  10. WHICH AIRBORNE CONTAMINANTS POSE THE GREATEST RISK TO WESTERN NATIONAL PARKS (USA)?

    EPA Science Inventory

    The Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 by the National Park Service to determine if airborne contaminants where having an impact on remote western ecosystems. Multiple sample media (snow, water, sediment, fish and terrestrial vegetatio...

  11. ARE AIRBORNE CONTAMINANTS A RISK FACTOR TO AQUATIC ECOSYSTEMS IN REMOTE WESTERN NATIONAL PARKS (USA)

    EPA Science Inventory

    The Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 by the National Park Service to determine if airborne contaminants were having an impact on remote western ecosystems. Multiple sample media (snow, water, sediment, fish and terrestrial vegetation...

  12. AIRBORNE CONTAMINANTS IN WESTERN NORTH AMERICAN NATIONAL PARKS--WHAT WE KNOW AND WANT TO LEARN

    EPA Science Inventory

    The National Park Service initiated the Western Airborne Contaminants Assessment Project (WACAP) in 2002 to determine if airborne contaminants from regional or distant sources have an impact on remote (typically high elevation) western ecosystems, including Alaska. Eight Nationa...

  13. RTAP: A mobile real time analytical platform for assessment of airborne contaminants

    SciTech Connect

    Mehta, U.J.; Paul, D.G.

    1995-12-31

    The Real Time Analytical Platform (RTAP) provides mobile airborne exposure level assessments for the Monitoring Branch of the US Army Operations Directorate, Chemical Support Division. In order to ensure worker safety and the protection of the environment, a variety of military compounds must be monitored during site-remediation and disposal operations. The instrumentation fielded in the RTAP incorporates an air sampling technique utilizing solid sorbent collection and thermal desorption technology combined with capillary gas chromatography and multiple gas chromatographic detectors. The mobile unit is equipped to analyze a number of surety compounds, delivering documentation to meet regulatory requirements with a high level of sensitivity and selectivity, in real time or near-real time. The system can sample continuously through a heated transfer hose for direct, on-line requirements during site monitoring projects, or easily switch to off-site sampling capability using solid sorbent cartridges for sample collection that are returned to the mobile unit or laboratory for analysis. A description of the instrumentation, screening and confirmation techniques, and instances where the units have been fielded as part of emergency response efforts at several sites will be included in the presentation.

  14. Active airborne contamination control using electrophoresis

    SciTech Connect

    Veatch, B.D.

    1994-06-01

    In spite of our best efforts, radioactive airborne contamination continues to be a formidable problem at many of the Department of Energy (DOE) weapons complex sites. For workers that must enter areas with high levels of airborne contamination, personnel protective equipment (PPE) can become highly restrictive, greatly diminishing productivity. Rather than require even more restrictive PPE for personnel in some situations, the Rocky Flats Plant (RFP) is actively researching and developing methods to aggressively combat airborne contamination hazards using electrophoretic technology. With appropriate equipment, airborne particulates can be effectively removed and collected for disposal in one simple process. The equipment needed to implement electrophoresis is relatively inexpensive, highly reliable, and very compact. Once airborne contamination levels are reduced, less PPE is required and a significant cost savings may be realized through decreased waste and maximized productivity. Preliminary ``cold,`` or non-radioactive, testing results at the RFP have shown the technology to be effective on a reasonable scale, with several potential benefits and an abundance of applications.

  15. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  16. Monitoring Groundwater Contaminant Plumes Using Airborne Geophysical Data

    NASA Astrophysics Data System (ADS)

    Robinson, Martin; Oftendinger, Ulrich; Ruffell, Alastair; Cowan, Marie; Cassidy, Rachel; Comte, Jean-Christophe; Wilson, Christopher; Desissa, Mohammednur

    2013-04-01

    Under the European Union Water Framework Directive, Member States are required to assess water quality across both surface water and groundwater bodies. Subsurface pollution plumes, originating from a variety of sources, pose a significant direct risk to water quality. The monitoring and characterisation of groundwater contaminant plumes is generally invasive, time consuming and expensive. In particular, adequately capturing the contaminant plume with monitoring installations, when the extent of the feature is unknown and the presence of contamination is only evident from indirect observations, can be prohibitively expensive. This research aims to identify the extent and nature of subsurface contaminant plumes using airborne geophysical survey data. This data was collected across parts of the island of Ireland within the scope of the original Tellus and subsequent Tellus Border projects. The rapid assessment of the airborne electro-magnetic (AEM) data allowed the identification of several sites containing possible contaminant plumes. These AEM anomalies were assessed through the analysis of existing site data and field site inspections, with areas of interest being examined for metallic structures that could affect the AEM data. Electrical resistivity tomography (ERT), ground penetrating radar (GPR) and ground-based electro-magnetic (EM) surveys were performed to ground-truth existing airborne data and to confirm the extent and nature of the affected area identified using the airborne data. Groundwater and surface water quality were assessed using existing field site information. Initial results collected from a landfill site underlain by basalt have indicated that the AEM data, coupled with ERT and GPR, can successfully be used to locate possible plumes and help delineate their extent. The analysis of a range of case study sites exhibiting different geological and environmental settings will allow for the development of a consistent methodology for examining the

  17. Comprehensive analysis of airborne contaminants from recent Spacelab missions

    NASA Technical Reports Server (NTRS)

    Matney, M. L.; Boyd, J. F.; Covington, P. A.; Leano, H. J.; Pierson, D. L.; Limero, T. F.; James, J. T.

    1993-01-01

    The Shuttle experiences unique air contamination problems because of microgravity and the closed environment. Contaminant build-up in the closed atmosphere and the lack of a gravitational settling mechanism have produced some concern in previous missions about the amount of solid and volatile airborne contaminants in the Orbiter and Spacelab. Degradation of air quality in the Orbiter/Spacelab environment, through processes such as chemical contamination, high solid-particulate levels, and high microbial levels, may affect crew performance and health. A comprehensive assessment of the Shuttle air quality was undertaken during STS-40 and STS-42 missions, in which a variety of air sampling and monitoring techniques were employed to determine the contaminant load by characterizing and quantitating airborne contaminants. Data were collected on the airborne concentrations of volatile organic compounds, microorganisms, and particulate matter collected on Orbiter/Spacelab air filters. The results showed that STS-40/42 Orbiter/Spacelab air was toxicologically safe to breathe, except during STS-40 when the Orbiter Refrigerator/Freezer unit was releasing noxious gases in the middeck. On STS-40, the levels of airborne bacteria appeared to increase as the mission progressed; however, this trend was not observed for the STS-42 mission. Particulate matter in the Orbiter/Spacelab air filters was chemically analyzed in order to determine the source of particles. Only small amounts of rat hair and food bar (STS-40) and traces of soiless medium (STS-42) were detected in the Spacelab air filters, indicating that containment for Spacelab experiments was effective.

  18. Migration of contaminated soil and airborne particulates to indoor dust.

    PubMed

    Layton, David W; Beamer, Paloma I

    2009-11-01

    We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, were used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase-out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust.

  19. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    NASA Technical Reports Server (NTRS)

    James, John T.

    2008-01-01

    The enclosed table lists official spacecraft maximum allowable concentrations (SMACs), which are guideline values set by the NASA/JSC Toxicology Group in cooperation with the National Research Council Committee on Toxicology (NRCCOT). These values should not be used for situations other than human space flight without careful consideration of the criteria used to set each value. The SMACs take into account a number of unique factors such as the effect of space-flight stress on human physiology, the uniform good health of the astronauts, and the absence of pregnant or very young individuals. Documentation of the values is given in a 5 volume series of books entitled "Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants" published by the National Academy Press, Washington, D.C. These books can be viewed electronically at http://books.nap.edu/openbook.php?record_id=9786&page=3. Short-term (1 and 24 hour) SMACs are set to manage accidental releases aboard a spacecraft and permit risk of minor, reversible effects such as mild mucosal irritation. In contrast, the long-term SMACs are set to fully protect healthy crewmembers from adverse effects resulting from continuous exposure to specific air pollutants for up to 1000 days. Crewmembers with allergies or unusual sensitivity to trace pollutants may not be afforded complete protection, even when long-term SMACs are not exceeded. Crewmember exposures involve a mixture of contaminants, each at a specific concentration (C(sub n)). These contaminants could interact to elicit symptoms of toxicity even though individual contaminants do not exceed their respective SMACs. The air quality is considered acceptable when the toxicity index (T(sub grp)) for each toxicological group of compounds is less than 1, where T(sub grp), is calculated as follows: T(sub grp) = C(sub 1)/SMAC(sub 1) + C(sub 2/SMAC(sub 2) + ...+C(sub n)/SMAC(sub n).

  20. Testing an innovative device against airborne Aspergillus contamination.

    PubMed

    Desoubeaux, Guillaume; Bernard, Marie-Charlotte; Gros, Valérie; Sarradin, Pierre; Perrodeau, Elodie; Vecellio, Laurent; Piscopo, Antoine; Chandenier, Jacques; Bernard, Louis

    2014-08-01

    Aspergillus fumigatus is a major airborne nosocomial pathogen that is responsible for severe mycosis in immunocompromised patients. We studied the efficacy of an innovative mobile air-treatment device in eliminating A. fumigatus from the air following experimental massive contamination in a high-security room. Viable mycological particles were isolated from sequential air samples in order to evaluate the device's effectiveness in removing the fungus. The concentration of airborne conidia was reduced by 95% in 18 min. Contamination was reduced below the detection threshold in 29 min, even when the machine was at the lowest airflow setting. In contrast, during spontaneous settling with no air treatment, conidia remained airborne for more than 1 h. This indoor air contamination model provided consistent and reproducible results. Because the air purifier proved to be effective at eliminating a major contaminant, it may prove useful in preventing air-transmitted disease agents. In an experimental space mimicking a hospital room, the AirLyse air purifier, which uses a combination of germicidal ultraviolet C irradiation and titanium photocatalysis, effectively eliminated Aspergillus conidia. Such a mobile device may be useful in routine practice for lowering microbiological air contamination in the rooms of patients at risk.

  1. Airborne trace contaminants of possible interest in CELSS

    NASA Technical Reports Server (NTRS)

    Garavelli, J. S.

    1986-01-01

    One design goal of Closed Ecological Life Support Systems (CELSS) for long duration space missions is to maintain an atmosphere which is healthy for all the desirable biological species and not deleterious to any of the mechanical components in that atmosphere. CELESS design must take into account the interactions of at least six major components; (1) humans and animals, (2) higher plants, (3) microalgae, (4) bacteria and fungi, (5) the waste processing system, and (6) other mechanical systems. Each of these major components can be both a source and a target of airborne trace contaminants in a CELSS. A range of possible airborne trace contaminants is discussed within a chemical classification scheme. These contaminants are analyzed with respect to their probable sources among the six major components and their potential effects on those components. Data on airborne chemical contaminants detected in shuttle missions is presented along with this analysis. The observed concentrations of several classes of compounds, including hydrocarbons, halocarbons, halosilanes, amines and nitrogen oxides, are considered with respect to the problems which they present to CELSS.

  2. FIELD ACTIVITIES AND PRELIMINARY RESULTS FROM THE INVESTIGATION OF WESTERN AIRBORNE CONTAMINANTS IN TWO HIGH ELEVATION WATERSHEDS OF ROCKY MOUNTAIN NATIONAL PARK

    EPA Science Inventory

    The National Park Service initiated the Western Airborne Contaminants Assessment Project (WACAP) in 2002 to determine if airborne contaminants from long-range transport and/or regional sources are having an impact on remote western ecosystems, including AK. Rocky Mountain Nation...

  3. Comparison of different hand-drying methods: the potential for airborne microbe dispersal and contamination.

    PubMed

    Best, E L; Redway, K

    2015-03-01

    Efficient washing and drying of hands is important in prevention of the transfer of micro-organisms. However, knowledge surrounding the potential for microbial contamination according to hand-drying methods is limited. This study assessed the potential for airborne microbe dispersal during hand drying by four methods (paper towels, roller towel, warm air and jet air dryer) using three different models. The jet air dryer dispersed liquid from users' hands further and over a greater range (up to 1.5m) than the other drying methods (up to 0.75 m), demonstrating the differing potential risks for airborne microbe dissemination, particularly if handwashing is suboptimal. PMID:25586988

  4. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants. Volume 2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Aeronautics and Space Administration (NASA) is aware of the potential toxicological hazards to humans that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMACs) for contaminants, and to review SMACs for various space-craft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to NASA's request, the NRC organized the Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants within the Committee On Toxicology (COT). In the first phase of its work, the subcommittee developed the criteria and methods for preparing SMACs for spacecraft contaminants. The subcommittee's report, entitled Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants, was published in 1992. The executive summary of that report is reprinted as Appendix A of this volume. In the second phase of the study, the Subcommittee on Spacecraft Maximum Allowable Concentrations reviewed reports prepared by NASA scientists and contractors recommending SMACs for approximately 35 spacecraft contaminants. The subcommittee sought to determine whether the SMAC reports were consistent with the 1992 guidelines. Appendix B of this volume contains the SMAC reports for 12 chemical contaminants that have been reviewed for

  5. Inversion of Airborne Contaminants in a Regional Model

    SciTech Connect

    Akcelik, V.; Biros, G.; Draganescu, A.; Ghattas, O.; Hill, J.; van Bloemen Waanders, B.; /SLAC /Pennsylvania U. /Texas U. /Sandia

    2007-01-10

    We are interested in a DDDAS problem of localization of airborne contaminant releases in regional atmospheric transport models from sparse observations. Given measurements of the contaminant over an observation window at a small number of points in space, and a velocity field as predicted for example by a mesoscopic weather model, we seek an estimate of the state of the contaminant at the beginning of the observation interval that minimizes the least squares misfit between measured and predicted contaminant field, subject to the convection-diffusion equation for the contaminant. Once the ''initial'' conditions are estimated by solution of the inverse problem, we issue predictions of the evolution of the contaminant, the observation window is advanced in time, and the process repeated to issue a new prediction, in the style of 4D-Var. We design an appropriate numerical strategy that exploits the spectral structure of the inverse operator, and leads to efficient and accurate resolution of the inverse problem. Numerical experiments verify that high resolution inversion can be carried out rapidly for a well-resolved terrain model of the greater Los Angeles area.

  6. Airborne Contaminants in the TE Lab: How to Reduce Your Exposure.

    ERIC Educational Resources Information Center

    Zeimet, Denis E.; Merrell, Wayne L.

    1995-01-01

    Details the dangers from airborne contaminants in technology education laboratories and ways to protect students from them, including ventilation, acceptable limits, and guidelines for using respirators. (SK)

  7. 30 CFR 57.5005 - Control of exposure to airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and use shall meet the following minimum requirements: (a) Respirators approved by NIOSH under 42 CFR... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Underground § 57.5005 Control of exposure to airborne contaminants. Control of employee exposure to...

  8. Water Protects Graphitic Surface from Airborne Hydrocarbon Contamination.

    PubMed

    Li, Zhiting; Kozbial, Andrew; Nioradze, Nikoloz; Parobek, David; Shenoy, Ganesh Jagadeesh; Salim, Muhammad; Amemiya, Shigeru; Li, Lei; Liu, Haitao

    2016-01-26

    The intrinsic wettability of graphitic materials, such as graphene and graphite, can be readily obscured by airborne hydrocarbon within 5-20 min of ambient air exposure. We report a convenient method to effectively preserve a freshly prepared graphitic surface simply through a water treatment technique. This approach significantly inhibits the hydrocarbon adsorption rate by a factor of ca. 20×, thus maintaining the intrinsic wetting behavior for many hours upon air exposure. Follow-up characterization shows that a nanometer-thick ice-like water forms on the graphitic surface, which remains stabilized at room temperature for at least 2-3 h and thus significantly decreases the adsorption of airborne hydrocarbon on the graphitic surface. This method has potential implications in minimizing hydrocarbon contamination during manufacturing, characterization, processing, and storage of graphene/graphite-based devices. As an example, we show that a water-treated graphite electrode maintains a high level of electrochemical activity in air for up to 1 day. PMID:26673269

  9. Detect-to-warn scenarios for defense against airborne contaminants

    NASA Astrophysics Data System (ADS)

    Cousins, Daniel; Campbell, Steven D.; Joseph, Rose

    2004-12-01

    Detect-to-warn defense strategies against airborne contamination are based on providing warning to personnel to take temporary protective actions. The effectiveness of such detect-to-warn active strategies is measured by the reduction in contaminant exposure compared to passive exposure. Effectiveness depends on several factors, including the contaminant release and transport properties, the warning sensor performance and the protective actions taken. In this paper we analyze effectiveness for several specific scenarios where certain reasonable protective actions are assumed and sensor performance is varied. One type of scenario analyzed is the protection of outdoor personnel against an upwind instantaneous point release. Meteorological conditions such as wind speed, turbulence level and heat flux, which result in high exposure levels are assumed. Personnel are warned to temporarily use filter masks based on a warning signal from a sensor placed between them and the release point. Another type of scenario is the protection of personnel inside of a building using active ventilation control. The building air handling properties, such as air exchange and recirculation, degree of leakage and filtration and zone volume, are representative of modern office buildings. Different sensor locations and ventilation control strategies are chosen to defend against outside and inside instantaneous point releases. In each scenario, we evaluate the dependence of effectiveness on sensor sensitivity threshold and response time. In addition, we describe desired values of other sensor attributes, such as false positive sensing rate, size, power consumption, maintenance frequency and procurement cost, to support realistic deployment and operations.

  10. Airborne molecular contamination: quality criterion for laser and optical components

    NASA Astrophysics Data System (ADS)

    Otto, Michael

    2015-02-01

    Airborne molecular contaminations (AMCs) have been recognized as a major problem in semiconductor fabrication. Enormous technical and financial efforts are made to remove or at least reduce these contaminations in production environments to increase yield and process stability. It can be shown that AMCs from various sources in laser devices have a negative impact on quality and lifetime of lasers and optical systems. Outgassing of organic compounds, especially condensable compounds were identified as the main source for deterioration of optics. These compounds can lead to hazing on surfaces of optics, degradation of coating, reducing the signal transmission or the laser signal itself and can enhance the probability of laser failure and damage. Sources of organic outgassing can be molding materials, resins, seals, circuit boards, cable insulation, coatings, paints and others. Critical compounds are siloxanes, aromatic amines and high boiling aromatic hydrocarbons like phthalates which are used as softeners in plastic materials. Nowadays all sensitive assembly steps are performed in controlled cleanroom environments to reduce risks of contamination. We will demonstrate a high efficient air filter concept to remove AMCs for production environments with special AMC filters and methods for the qualification and monitoring of these environments. Additionally, we show modern techniques and examples for the pre-qualification of materials. For assembled components, we provide sampling concepts for a routine measurement for process, component and product qualification. A careful selection of previously tested and certified materials and components is essential to guarantee the quality of lasers and optical devices.

  11. Occupational exposure to airborne contaminants during offshore oil drilling.

    PubMed

    Kirkhus, Niels E; Thomassen, Yngvar; Ulvestad, Bente; Woldbæk, Torill; Ellingsen, Dag G

    2015-07-01

    The aim was to study exposure to airborne contaminants in oil drillers during ordinary work. Personal samples were collected among 65 drill floor workers on four stationary and six moveable rigs in the Norwegian offshore sector. Air concentrations of drilling mud were determined based on measurements of the non-volatile mud components Ca and Fe. The median air concentration of mud was 140 μg m(-3). Median air concentrations of oil mist (180 μg m(-3)), oil vapour (14 mg m(-3)) and organic carbon (46 μg m(-3)) were also measured. All contaminants were detected in all work areas (drill floor, shaker area, mud pits, pump room, other areas). The highest air concentrations were measured in the shaker area, but the differences in air concentrations between working areas were moderate. Oil mist and oil vapour concentrations were statistically higher on moveable rigs than on stationary rigs, but after adjusting for differences in mud temperature the differences between rig types were no longer of statistical significance. Statistically significant positive associations were found between mud temperature and the concentrations of oil mist (Spearman's R = 0.46) and oil vapour (0.39), and between viscosity of base oil and oil mist concentrations. Use of pressure washers was associated with higher air concentrations of mud. A series of 18 parallel stationary samples showed a high and statistically significant association between concentrations of organic carbon and oil mist (r = 0.98). This study shows that workers are exposed to airborne non-volatilized mud components. Air concentrations of volatile mud components like oil mist and oil vapour were low, but were present in all the studied working areas.

  12. Occupational exposure to airborne contaminants during offshore oil drilling.

    PubMed

    Kirkhus, Niels E; Thomassen, Yngvar; Ulvestad, Bente; Woldbæk, Torill; Ellingsen, Dag G

    2015-07-01

    The aim was to study exposure to airborne contaminants in oil drillers during ordinary work. Personal samples were collected among 65 drill floor workers on four stationary and six moveable rigs in the Norwegian offshore sector. Air concentrations of drilling mud were determined based on measurements of the non-volatile mud components Ca and Fe. The median air concentration of mud was 140 μg m(-3). Median air concentrations of oil mist (180 μg m(-3)), oil vapour (14 mg m(-3)) and organic carbon (46 μg m(-3)) were also measured. All contaminants were detected in all work areas (drill floor, shaker area, mud pits, pump room, other areas). The highest air concentrations were measured in the shaker area, but the differences in air concentrations between working areas were moderate. Oil mist and oil vapour concentrations were statistically higher on moveable rigs than on stationary rigs, but after adjusting for differences in mud temperature the differences between rig types were no longer of statistical significance. Statistically significant positive associations were found between mud temperature and the concentrations of oil mist (Spearman's R = 0.46) and oil vapour (0.39), and between viscosity of base oil and oil mist concentrations. Use of pressure washers was associated with higher air concentrations of mud. A series of 18 parallel stationary samples showed a high and statistically significant association between concentrations of organic carbon and oil mist (r = 0.98). This study shows that workers are exposed to airborne non-volatilized mud components. Air concentrations of volatile mud components like oil mist and oil vapour were low, but were present in all the studied working areas. PMID:26020723

  13. Assessing human exposure to airborne pollutants: Advances and opportunities

    SciTech Connect

    Lioy, P.J. )

    1991-08-01

    A committee which was convened by the National Research Council, recently completed an analysis of new methods and technologies for assessing exposure to air pollutants. The committee identified three major ways of determining human exposure to airborne pollutants. Monitoring the air around an individual with a portable personal air sampler is, of course, the most comprehensive and most accurate. It is also the costliest and most time consuming. The second method is more indirect and involves techniques such as measuring the amount of a contaminant with a stationary monitor and extrapolating exposure by means of personal activity records or mathematical models. Exposure to carbon monoxide inside a car, for example, might be roughly calculated from the amount of time spent in the car and the quantity of carbon monoxide in the car under typical operating conditions. The third method involves biological markers as a measure of the integrated dose within the body and of past contact with pollutants. For example, a marker for airborne lead exposure can be elevated lead levels in the blood. However, this must be weighed against contributions from other media. A final and major point made in the report is the need to have accurate and realistic assessments to ensure optimal reduction of human exposure. To accomplish this, exposure assessment research should be supported by government programs. Although not stated, such research should also be supported by other sectors, including the regulated community.

  14. Movement of airborne contaminants in a hospital isolation room

    PubMed Central

    Eames, I.; Shoaib, D.; Klettner, C. A.; Taban, V.

    2009-01-01

    We analyse the characteristics of a force-ventilated isolation room, and the contributions to transport caused by the movement of people and doors opening/closing. The spread of fine droplets and particles can be understood, to leading order, by considering the movement of passive contaminants. A scaled (1:10) model of an isolation room (with water instead of air) was used to analyse the dilution of a passive contaminant (food dye), released either instantaneously or at a constant rate. The high level of turbulence, typical of isolation rooms, ensures that the dye concentration is uniform within the model room and mixing is perfect, and the measured mean concentration can be predicted theoretically. In a second series of experiments, the exchange generated by a door opening/closing is measured for different opening angles. A dipolar vortex is generated at the tip of the door which moves into the centre of the room, with a large coherent structure moving along the wall. The exchange volume is comparable to the swept volume of the door. Larger droplets and particles do not move passively. Their movement within a turbulent flow is studied by combining a Lagrangian model of particle movement with a kinematic simulation of a pseudo turbulent flow. The results show that while the mean fall velocity of particles is largely unchanged, turbulence significantly enhances horizontal and vertical dispersion. The horizontal spread as a function of the level of turbulence and droplet properties is estimated. The conclusions from both studies are brought together and discussed in the context of the airborne spread of contaminants within a general hospital room. PMID:19815576

  15. 30 CFR 56.5005 - Control of exposure to airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: (a) Respirators approved by NIOSH under 42 CFR part 84 which are applicable and suitable for the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne...

  16. Airborne chemical contamination of a chemically amplified resist

    NASA Astrophysics Data System (ADS)

    MacDonald, Scott A.; Clecak, Nicholas J.; Wendt, H. R.; Willson, C. Grant; Snyder, Clinton D.; Knors, C. J.; Deyoe, N. B.; Maltabes, John G.; Morrow, James R.; McGuire, Anne E.; Holmes, Steven J.

    1991-06-01

    We have found that the performance of the t-BOC/onium salt resist system is severely degraded by vapor from organic bases. This effect is very pronounced and can be observed when the coated wafers stand for 15 minutes in air containing as little as 15 parts per billion (ppb) of an organic base. The observed effect, caused by this chemical contamination, depends on the tone of the resist system. For negative tone systems the UV exposure dose, required to obtain the correct linewidth, increases. While for the positive tone system, one observes the generation of a skin at the resist-air interface. Both effects are caused by the photogenerated acid being neutralized by the airborne organic base. There are a wide variety of commonly used materials which can liberate trace amounts of volatile amines and degrade resist performance. For example, fresh paint on a laboratory wall can exhibit this detrimental effect. These effects can be minimized by storing and processing the resist coated wafers in air that has passed through a specially designed, high efficiency carbon filter. The implementation of localized air filtration, to bathe the resist in chemically pure air, enabled this resist system to operate in a manufacturing environment at a rate of 100 wafers/hour.

  17. Environmental contamination and airborne microbial counts: a role for hydroxyl radical disinfection units?

    PubMed

    Wong, V; Staniforth, K; Boswell, T C

    2011-07-01

    Environmental contamination is thought to play a role in the spread of infection in hospitals and there has been increased interest in novel air disinfection systems in preventing infection. In this study the efficacy of a hydroxyl radical air disinfection system (Inov8 unit) in reducing the number of airborne bacteria was assessed in a clinical setting. Environmental contamination was assessed using settle plates and air samples in three settings: (1) non-clinical room; (2) non-clinical room with defined activity; and (3) single intensive care unit cubicle. A comparison of air counts and environmental contamination rates was made with the Inov8 units on and off. The Inov8 unit produced an overall reduction in both air sample and settle plate counts in each setting (P<0.001, Wilcoxon signed-rank test). There was a mean reduction in air sample counts of 26%, 39% and 55% for settings 1, 2 and 3 respectively. The corresponding reductions in settle plate counts were 35%, 62% and 54%. These results suggest that this type of novel air disinfection may have a role in improving air quality and reducing environmental contamination within clinical isolation rooms. Further work is required to assess the effect on specific pathogens, and to establish whether this will reduce the risks of patients and/or healthcare workers acquiring such pathogens from the environment.

  18. Western Airborne Contaminants Assessment Project Database

    EPA Science Inventory

    WACAP has received considerable recognition from the media with over 200 local, national and international media outlets. At present count, 10 peer-reviewed papers have been published. In response to the WACAP results, the NPS convened multi-agency workshops with WACAP PIs and l...

  19. Evaluation of ULPA/prefilter media for the reduction of airborne boron contamination

    NASA Astrophysics Data System (ADS)

    Squatrito, John; Nanez, Raul, Jr.; Keeton, Dewey

    1995-09-01

    An investigation was conducted to evaluate various combinations of filter media to minimize boron contamination in clean room environments. Three (mu) PVC fan/blower test chamber modules were constructed, each with a different filter media and placed in a clean room environment. The various media tested included a standard Ultra Low Penetration Air (ULPA), an expanded polytetrafluoroethylene (PTFE) ULPA, and a combination of PTFE with a chemically active prefilter (carbon based). An encapsulation procedure was used to trap airborne contamination on the exposed area of a wafer and sandwich contaminants. The sandwiched contaminants at these controlled interfaces are tested for boron contamination levels. Secondary Ion Mass Spectroscopy (SIMS) was used to determine boron contamination levels at each controlled interface. Results from these experiments were used to quantify the effectiveness of different types of ULPA filters on airborne boron contaminants.

  20. An assessment of the airborne route in hepatitis B transmission.

    PubMed

    Petersen, N J

    1980-01-01

    The experimental and epidemiologic evidence for airborne transmission of hepatitis B is inconclusive and our efforts to detect airborne HBsAg or blood in environments where hepatitis B transmission occurs have been uniformly unsuccessful. In the specific areas investigated: dialysis centers, laboratories, and dental operatories, other major routes of transmission that can explain the spread of hepatitis B invariably are present. Therefore, while airborne taansmission is theoretically possible and probably has occurred, at this time its contribution to the overfall hepatitis B problem cannot be quantitated. we fell comfortable in concluding that airborne HBV does not play a major role in hepatitis B transmission and that true airborne infections are probably rare. Because of the fine line airborne transmission from contract transmission via droplets, we feel it important to emphasize the need to take those precautions that protect against the latter. These include the use of gloves where surfaces become contaminated and masks and glasses to protect the eyes, nose and mouth where the possibility of spatter exists.

  1. Importance of airborne contamination during dressing of beef and lamb carcasses.

    PubMed

    Burfoot, Dean; Whyte, Robin; Tinker, David; Howell, Mary; Hall, Karen; Holah, John; Smith, Debra; White, Rodger; Baker, David; McIntosh, Jane

    2006-12-01

    Carcasses along slaughter lines were exposed to normal slaughterhouse air or ultraclean air provided from a unit fitted with a HEPA filter. In cattle slaughterhouses, aerobic viable counts were measured by sponging the brisket at the end of the line to determine whether the slaughterhouse air had led to contamination of the carcasses. Furthermore, a replica cattle carcass with settle plates attached was exposed to similar conditions. The greatest contamination of the plates occurred at the hide puller (P < 0.01). The use of ultraclean air reduced the deposition of organisms onto settle plates (P < 0.01). The airborne route contributed to contamination in cattle slaughterhouses, but other vectors were more important. Further study of contamination of the brisket, at the time that it was first exposed, showed that knives transfer contamination from the hide. The use of ultraclean air at this position showed that the airborne route was a contributor to contamination (P < 0.1), but it was not the greatest vector. In lamb slaughterhouses, the highest counts on settle plates were found at the fleece puller (P < 0.05). The highest counts on the lamb carcasses were found on the brisket exposed from the start of the line to just after the fleece puller (P < 0.05). There was no clear relationship between the measured counts and the concentration of organisms in the air, indicating that the airborne route in lamb slaughterhouses contributes less to carcass contamination than do the surface contacts. PMID:17186646

  2. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    NASA Astrophysics Data System (ADS)

    Cooper, B. L.; McKay, D. S.; Taylor, L. A.; Wallace, W. T.; James, J.; Riofrio, L.; Gonzalez, C. P.

    2009-12-01

    The Lunar Airborne Dust Toxicity Assessment Group (LADTAG) is developing data to set the permissible limits for human exposure to lunar dust. This standard will guide the design of airlocks and ports for EVA, as well as the requirements for filtering and monitoring the atmosphere in habitable vehicles, rovers and other modules. LADTAG’s recommendation for permissible exposure limits will be delivered to the Constellation Program in late 2010. The current worst-case exposure limit of 0.05 mg/m3, estimated by LADTAG in 2006, reflects the concern that lunar dust may be as toxic as quartz dust. Freshly-ground quartz is known to be more toxic than un-ground quartz dust. Our research has shown that the surfaces of lunar soil grains can be more readily activated by grinding than quartz. Activation was measured by the amount of free radicals generated—activated simulants generate Reactive Oxygen Species (ROS) i.e., production of hydroxyl free radicals. Of the various influences in the lunar environment, micrometeorite bombardment probably creates the most long-lasting reactivity on the surfaces of grains, although solar wind impingement and short-wavelength UV radiation also contribute. The comminution process creates fractured surfaces with unsatisfied bonds. When these grains are inhaled and carried into the lungs, they will react with lung surfactant and cells, potentially causing tissue damage and disease. Tests on lunar simulants have shown that dissolution and leaching of metals can occur when the grains are exposed to water—the primary component of lung fluid. However, simulants may behave differently than actual lunar soils. Rodent toxicity testing will be done using the respirable fraction of actual lunar soils (particles with physical size of less than 2.5 micrometers). We are currently separating the fine material from the coarser material that comprises >95% of the mass of each soil sample. Dry sieving is not practical in this size range, so a new system

  3. Spacecraft maximum allowable concentrations for selected airborne contaminants, volume 1

    NASA Technical Reports Server (NTRS)

    1994-01-01

    As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMAC's) for contaminants, and to review SMAC's for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to NASA's request, the NRC organized the Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants within the Committee on Toxicology (COT). In the first phase of its work, the subcommittee developed the criteria and methods for preparing SMAC's for spacecraft contaminants. The subcommittee's report, entitled Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants, was published in 1992. The executive summary of that report is reprinted as Appendix A of this volume. In the second phase of the study, the Subcommittee on Spacecraft Maximum Allowable Concentrations reviewed reports prepared by NASA scientists and contractors recommending SMAC's for 35 spacecraft contaminants. The subcommittee sought to determine whether the SMAC reports were consistent with the 1992 guidelines. Appendix B of this volume contains the first 11 SMAC reports that have been reviewed for their application of the guidelines developed in the first phase of this activity and approved by the subcommittee.

  4. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants. Volume 5

    NASA Technical Reports Server (NTRS)

    2008-01-01

    To protect space crews from air contaminants, NASA requested that the National Research Council (NRC) provide guidance for developing spacecraft maximum allowable concentrations (SMACs) and review NASA's development of exposure guidelines for specific chemicals. The NRC convened the Committee on Spacecraft Exposure Guidelines to address this task. The committee published Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants (NRC 1992). The reason for the review of chemicals in Volume 5 is that many of them have not been examined for more than 10 years, and new research necessitates examining the documents to ensure that they reflect current knowledge. New knowledge can be in the form of toxicologic data or in the application of new approaches for analysis of available data. In addition, because NASA anticipates longer space missions beyond low Earth orbit, SMACs for 1,000-d exposures have also been developed.

  5. Overview of the risk of respiratory cancer from airborne contaminants.

    PubMed Central

    Speizer, F E

    1986-01-01

    This overview on defining risk of respiratory cancer from airborne pollutants summarizes broad issues related to a number of the environmental agents that are discussed in the articles that follow. Lung cancer kills more than 100,000 people annually and is the major form of cancer in both sexes in middle age. Cigarette smoking is the major cause of respiratory cancer and must be taken into account in any study of the effect of an environmental agent on the risk of respiratory cancer, particularly at relatively low levels of excess risk (RR greater than 1.0 but less than 2.0). The agents considered in this series all have the potential for widespread community exposures, either because there is widespread long-term exposure (passive smoking), the agents are direct byproducts of energy consumption (organic particles), have ubiquitous production and use patterns (formaldehyde and fibers), or occur widely in natural settings (radon). Several issues--measurement of exposure, latency, confounding factors and bias, extrapolation from animals to humans, population at risk, and attributable risk--must be considered for each agent. A further issue related to exposure estimates is the relationship of exposure to actual dose. Understanding exposure some 25 to 40 years in the past is important because of the prolonged latency period in the development of respiratory cancers. To the degree that these agents act synergistically with smoking, the reduction of smoking or of exposure to these agents may have greater public health consequences than would be anticipated from the directly measured attributable risk of each of these agents separately. PMID:3830117

  6. Seasonal Variability in Airborne Biotic Contaminants in Swine Confinement Buildings

    PubMed Central

    Kumari, Priyanka; Choi, Hong L.

    2014-01-01

    Little is known about the seasonal dynamics of biotic contaminants in swine confinement buildings (SCBs). The biotic contaminants of seven SCBs were monitored during one visit in the winter and one during the summer. Paired-end Illumina sequencing of the 16S rRNA gene, V3 region, was used to examine seasonal shifts in bacterial community composition and diversity. The abundances of 16S rRNA genes and six tetracycline resistance genes (tetB, tetH, tetZ, tetO, tetQ, and tetW) were also quantified using real-time PCR. Bacterial abundances, community composition and diversity all showed strong seasonal patterns defined by winter peaks in abundance and diversity. Microclimatic variables of SCBs, particularly air speed, PM2.5 and total suspended particles (TSP) were found significantly correlated to abundances, community composition, and diversity of bacterial bioaerosols. Seasonal fluctuations were also observed for four tetracycline resistance genes, tetH, tetO, tetQ, and tetW. The frequency of occurrences of these resistance genes were significantly higher in samples collected during winter and was also significantly correlated with air speed, PM2.5 and TSP. Overall, our results indicate that biotic contaminants in SCBs exhibit seasonal trends, and these could be associated with the microclimatic variables of SCBs. The correlations established in the current study could be helpful in establishing better management strategies to minimize the potential health impacts on both livestock and humans working in this environment. PMID:25393011

  7. 78 FR 54956 - Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... AFFAIRS Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment....rennie@va.gov . Please refer to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.'' SUPPLEMENTARY INFORMATION: Title: Open Burn Pit Registry Airborne Hazard...

  8. Terrestrial Method for Airborne Lidar Quality Control and Assessment

    NASA Astrophysics Data System (ADS)

    Alsubaie, N. M.; Badawy, H. M.; Elhabiby, M. M.; El-Sheimy, N.

    2014-11-01

    Most of LiDAR systems do not provide the end user with the calibration and acquisition procedures that can use to validate the quality of the data acquired by the airborne system. Therefore, this system needs data Quality Control (QC) and assessment procedures to verify the accuracy of the laser footprints and mainly at building edges. This research paper introduces an efficient method for validating the quality of the airborne LiDAR point clouds data using terrestrial laser scanning data integrated with edge detection techniques. This method will be based on detecting the edge of buildings from these two independent systems. Hence, the building edges are extracted from the airborne data using an algorithm that is based on the standard deviation of neighbour point's height from certain threshold with respect to centre points using radius threshold. The algorithm is adaptive to different point densities. The approach is combined with another innovative edge detection technique from terrestrial laser scanning point clouds that is based on the height and point density constraints. Finally, statistical analysis and assessment will be applied to compare these two systems in term of edge detection extraction precision, which will be a priori step for 3D city modelling generated from heterogeneous LiDAR systems

  9. Methods to assess airborne concentrations of cotton dust.

    PubMed

    Corn, M

    1987-01-01

    Assessment of concentrations of airborne cotton dust in the factory is necessary to determine adherence to applicable Permissible Exposure Limits (PELs) on a day-to-day basis, as well as for investigatory studies of an epidemiological nature. The latter are required on an ongoing basis to determine the adequacy of PELs to prevent disease in the exposed population. A strategy of sampling includes considerations of the numbers of samples to be obtained for statistical validity and the locations of samples. Current practice is to obtain more "personal samples" of exposure wherever possible, but with regard to cotton dust, instrumentation is not available for such sampling. In the U.S., the vertical elutriator is the instrument of choice for determining the concentrations of cotton dust in air. Results are expressed as milligrams of airborne particulate (cotton dust) per cubic meter. PMID:3434562

  10. Fate of Airborne Contaminants in Okefenokee National Wildlife Refuge

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.

    1997-01-01

    weight in liver and kidney, and raccoons (Procyon lotor) >16 ?g/g dry weight in the liver and kidney. Lead averaged 1 ?g/L in rainfall, 6.6 ?g/L in surface water, 9.8 ?g/L in pore water, 12.3 ?g/g in floc and 12.5 ?g/g in sediments. Lead in fish muscle was ~0.1 ?g/g and >1.2 ?g/g in bone, alligator kidney had 1.5 ?g/g lead and liver had 3.8 ?g/g; raccoon kidney and liver averaged about 1 ?g/g. Historical patterns of mercury deposition based on 210Pb aging of the core sample showed mercury increased from pre-1800 concentrations of 500 ng/g in the 1950s, with a subsequent decline to current levels. Lead concentrations in the core sample followed a similar pattern as that of mercury. Okefenokee Swamp serves as a sump for the cations and anions deposited through rainfall. Although mercury and lead levels in the biota are not currently acutely hazardous, concentrations are high enough to cause adverse chronic effects on behavioral, physiological or reproductive functions of resident biota, especially piscivorous species. To protect trust resources associated with the Refuge, activities and developments in the airshed that have the potential to increase atmospheric contamination, especially for lead and mercury, should be curtailed.

  11. Long-term airborne contamination studied by attic dust in an industrial area: Ajka, Hungary

    NASA Astrophysics Data System (ADS)

    Völgyesi, P.; Jordan, G.; Szabo, Cs.

    2012-04-01

    Heavy industrial activities such as mining, metal industry, coal fired power plants have produced large amount of by-products and wide-spread pollution, particularly in the period of centrally dictated economy after WWII, in Hungary. Several studies suggest that significant amount of these pollutants have been deposited in the urban environment. Nowadays, more than half of the world's population is living in urban areas and people spend almost 80% of their lives indoors in developed countries increasing human health risk due to contamination present in urban dwellings. Attic dust sampling was applied to determine the long-term airborne contamination load in the industrial town of Ajka (Hungary). There has been a high industrial activity in Ajka since the end of the 19th century. In addition to aluminum and alumina industry, coal mining, coal fired power plant and glass industry sites, generated numerous waste heaps which act as multi-contamination sources in the area. In October 2010 the Ajka red mud tailings pond failed and caused an accidental regional contamination of international significance. The major objective of this research was to study and map the spatial distribution of heavy metal contamination in airborne attic dust samples. At 27 sampling sites 30 attic dust samples were collected. Sampling strategy followed a grid-based stratified random sampling design. In each cell a house for attic dust sample collection was selected that was located the closest to a randomly generated point in the grid cell. The project area covers a 8x8 grid of 1x1 km cells with a total area of 64 km2. In order to represent long-term industrial pollution, houses with attics kept intact for at least 30-40 years were selected for sampling. Sampling included the collection of background samples remotely placed from the industrialized urban area. The concentration of the major and toxic elements (Al, Ca, Fe, K, Mg, Mn, Na, P, S, and As, Ba, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Se, Sn

  12. Indoor air climate and microbiological airborne: contamination in various hospital areas.

    PubMed

    Berardi, B M; Leoni, E

    1993-07-01

    Indoor climate indices and microbiological airborne contamination were evaluated in a department of a general hospital in Bologna only partially equipped with an air conditioning system. To determine the environmental parameters, an ANADATA (LSI) climate analyzer with relative transducers was used. The Effective Temperature (ET), the New Effective Temperature (ET*) and the Fanger indices (PMV-PPD) were calculated using the parameters measured. Microbial count measurements were taken with an S.A.S. (Surface Air System) sampler, to ascertain the total bacterial count at 37 degrees C, and the fungal particle, Staphylococcus aureus and Pseudomonas aeruginosa counts. Carbon dioxide air concentrations were also measured to evaluate the efficacy of air exchange. The Fanger indices were not within the range of thermal comfort in most rooms (52% in winter, 62% in summer). Air microbial counts were higher in the hospital wards and surgeries than in the offices and laboratories. In particular, coagulase-positive staphylococci were present only in the air of the patients' rooms. The microbial contamination was not correlated with the air conditioning system, but probably caused by the turnover in the hospital population, the number of people and their behaviour. However the most important measure to prevent airborne contamination and to reduce the number of microorganisms in the air is an efficient source control. Better management of the air conditioning system, by means of adequate air exchange and thermal adjustment, would lead to a notable improvement in indoor air quality, especially in units with hospitalized patients.

  13. The Development of Airborne Data for Assessing Models (ADAM) - A central repository of airborne field campaign data archives

    NASA Astrophysics Data System (ADS)

    Chen, G.; Kleb, M. M.; Aknan, A. A.; Brown, C. C.; Mangosing, D. C.; Thornhill, A.; Rinsland, P. L.

    2010-12-01

    NASA, NOAA, and NSF have conducted over 30 airborne campaigns during the past three decades aimed at gaining an understanding of the tropospheric chemical and physical processes related to climate change and air-quality issues. In recent years, the scientific value of this accumulated airborne data has been increasingly recognized for use in satellite validation and model assessment and evaluation activities. In addition to the high spatial-temporal resolutions, the airborne data, especially from the more recent studies, offers a comprehensive view of the atmosphere through a large suite of the simultaneously observed atmospheric species/parameters, ranging from photochemical precursors to products as well as particle chemical, microphysical, and optical properties. To better facilitate the model assessment and evaluation activities, we are actively engaged in the development of a web-based central airborne data archive: ADAM (Airborne Data for Assessing Models). This effort is sponsored by the NASA MEaSUREs program and is intended to archive data from tropospheric chemistry airborne field campaign since the 1980s. The principal design philosophy of the ADAM web site is to provide an intuitive user interface that allows users to browse, visualize, subset (both spatially and temporally), merge, and download the airborne data, as well as providing adequate metadata associated with the data archive. A working version of the web site which shows the ADAM user interface and functionalities will be presented. Also presented are conventions to establish common names for the atmospheric variables which are often observed during airborne campaigns as well as the approaches to handle missing data and limit of detections. This presentation is intended to serve the purpose of getting feedback from the broad atmospheric community, including both modelers and measurement experts.

  14. Computerized Mathematical Models of Spray Washout of Airborne Contaminants (Radioactivity) in Containment Vessels.

    2003-05-23

    Version 01 Distribution is restricted to the United States Only. SPIRT predicts the washout of airborne contaminants in containment vessels under postulated loss-of-coolant accident (LOCA) conditions. SPIRT calculates iodine removal constants (lambdas) for post-LOCA containment spray systems. It evaluates the effect of the spectrum of drop sizes emitted by the spray nozzles, the effect of drop coalescence, and the precise solution of the time-dependent diffusion equation. STEAM-67 routines are included for calculating the properties ofmore » steam and water according to the 1967 ASME Steam Tables.« less

  15. A global indicator as a tool to follow airborne molecular contamination in a controlled environment.

    PubMed

    Cariou, Stéphane; Guillot, Jean-Michel; Pépin, Laurence; Kaluzny, Pascal; Faure, Louis-Paul

    2005-02-01

    The impact of pollutants on production quality in nanotechnology necessitates reduction of contaminant levels in cleanrooms. So, devising a global airborne-pollutant indicator (GAPI) for rapid determination of the level of pollution and its danger to the process is justified. This tool used relative impact weights of the different molecules to quantify the pollution. A calculation of impact weight is proposed in this paper. Impact weights could take into account several characteristics of the molecules (molecular volume, sticking coefficient, ...). They could also be combined to be as close as possible to reality. An example of calculations of the impact of molecular volumes on air quality is given.

  16. Monitoring airborne biotic contaminants in the indoor environment of pig and poultry confinement buildings.

    PubMed

    Hong, Pei-Ying; Li, Xiangzhen; Yang, Xufei; Shinkai, Takumi; Zhang, Yuanhui; Wang, Xinlei; Mackie, Roderick I

    2012-06-01

    Given the growing concerns over human and animal health issues related to confined animal feeding operations, an in-depth examination is required to monitor for airborne bacteria and associated antibiotic resistance genes. Our 16S rRNA-based pyrosequencing revealed that the airborne microbial community skewed towards a higher abundance of Firmicutes (> 59.2%) and Bacteroidetes (4.2-31.4%) within the confinement buildings, while the office environment was predominated by Proteobacteria (55.2%). Furthermore, bioaerosols in the confinement buildings were sporadically associated with genera of potential pathogens, and these genera were more frequently observed in the bioaerosols of pig and layer hen confinement than the turkey confinement buildings and office environment. High abundances of tetracycline resistance genes (9.55 × 10(2) to 1.69 × 10(6) copies ng(-1) DNA) were also detected in the bioaerosols sampled from confinement buildings. Bacterial lineages present in the poultry bioaerosols clustered apart from those present in the pig bioaerosols and among the different phases of pig production, suggesting that different livestock as well as production phase were associated with a distinct airborne microbial community. By understanding the diversity of biotic contaminants associated with the different confinement buildings, this study facilitates the implementation of better management strategies to minimize potential health impacts on both livestock and humans working in this environment. PMID:22414212

  17. Evaluation of a cubicle containment system in preventing gaseous and particulate airborne cross-contamination

    SciTech Connect

    White, W.J.; Hughes, H.C.; Singh, S.B.; Lang, C.M.

    1983-12-01

    The effectiveness of a cubicle containment system in preventing gaseous and particulate cross-contamination in animal facilities was evaluated using several techniques. Using a nitrous oxide dilution technique, no airborne cross-contamination was found between cubicles as long as all cubicle doors were kept closed. If the doors to the cubicle in which the gas was released were partially or completely opened, low concentrations of nitrous oxide could be detected in adjacent cubicles. These concentrations increased when the air exchange rates in the cubicle were decreased. Similar results were obtained when particulate transfer was measured using aerosolized Staphlococcus epidermidis and a slit to agar sampling technique. Air flows and point air velocities within the cubicle and the animal room were also studied. A trial of Sendai virus transmission between cubicles revealed no intercubicle transmission after 3 weeks of exposure. Overall, the cubicle containment system appeared to be an effective means of achieving limited biohazard containment, applicable to many research housing needs.

  18. Evaluation of a cubicle containment system in preventing gaseous and particulate airborne cross-contamination.

    PubMed

    White, W J; Hughes, H C; Singh, S B; Lang, C M

    1983-12-01

    The effectiveness of a cubicle containment system in preventing gaseous and particulate cross-contamination in animal facilities was evaluated using several techniques. Using a nitrous oxide dilution technique, no airborne cross-contamination was found between cubicles as long as all cubicle doors were kept closed. If the doors to the cubicle in which the gas was released were partially or completely opened, low concentrations of nitrous oxide could be detected in adjacent cubicles. These concentrations increased when the air exchange rates in the cubicle were decreased. Similar results were obtained when particulate transfer was measured using aerosolized Staphlococcus epidermidis and a slit to agar sampling technique. Air flows and point air velocities within the cubicle and the animal room were also studied. A trial of Sendai virus transmission between cubicles revealed no intercubicle transmission after 3 weeks of exposure. Overall, the cubicle containment system appeared to be an effective means of achieving limited biohazard containment, applicable to many research housing needs.

  19. Vegetation canopy discrimination and biomass assessment using multipolarized airborne SAR

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.; Dobson, M. C.; Held, D. N.

    1985-01-01

    Multipolarized airborne Synthetic Aperture Radar (SAR) data were acquired over a largely agricultural test site near Macomb, Illinois, in conjunction with the Shuttle Imaging Radar (SIR-B) experiment in October 1984. The NASA/JPL L-band SAR operating at 1.225 GHz made a series of daily overflights with azimuth view angles both parallel and orthogonal to those of SIR-B. The SAR data was digitally recorded in the quadpolarization configuration. An extensive set of ground measurements were obtained throughout the test site and include biophysical and soil measurements of approximately 400 agricultural fields. Preliminary evaluation of some of the airborne SAR imagery indicates a great potential for crop discrimination and assessment of canopy condition. False color composites constructed from the combination of three linear polarizations (HH, VV, and HV) were found to be clearly superior to any single polarization for purposes of crop classification. In addition, an image constructed using the HH return to modulate intensity and the phase difference between HH and VV returns to modulate chroma indicates a clear capability for assessment of canopy height and/or biomass. In particular, corn fields heavily damaged by infestations of corn borer are readily distinguished from noninfested fields.

  20. Destruction of problematic airborne contaminants by hydrogen reduction using a Catalytically Active, Regenerable Sorbent (CARS)

    NASA Technical Reports Server (NTRS)

    Thompson, John O.; Akse, James R.

    1993-01-01

    Thermally regenerable sorbent beds were demonstrated to be a highly efficient means for removal of toxic airborne trace organic contaminants aboard spacecraft. The utilization of the intrinsic weight savings available through this technology was not realized since many of the contaminants desorbed during thermal regeneration are poisons to the catalytic oxidizer or form highly toxic oxidation by-products in the Trace Contaminant Control System (TCCS). Included in this class of compounds are nitrogen, sulfur, silicon, and halogen containing organics. The catalytic reduction of these problematic contaminants using hydrogen at low temperatures (200-300 C) offers an attractive route for their destruction since the by-products of such reactions, hydrocarbons and inorganic gases, are easily removed by existing technology. In addition, the catalytic oxidizer can be operated more efficiently due to the absence of potential poisons, and any posttreatment beds can be reduced in size. The incorporation of the catalyst within the sorbent bed further improves the system's efficiency. The demonstration of this technology provides the basis for an efficient regenerable TCCS for future NASA missions and can be used in more conventional settings to efficiently remove environmental pollutants.

  1. Airborne Transmission of Melioidosis to Humans from Environmental Aerosols Contaminated with B. pseudomallei

    PubMed Central

    Lin, Hsi-Hsun; Liu, Pei-Ju; Ni, Wei-Fan; Hsueh, Pei-Tan; Liang, Shih-Hsiung; Chen, Chialin; Chen, Ya-Lei

    2015-01-01

    Melioidosis results from an infection with the soil-borne pathogen Burkholderia pseudomallei, and cases of melioidosis usually cluster after rains or a typhoon. In an endemic area of Taiwan, B. pseudomallei is primarily geographically distributed in cropped fields in the northwest of this area, whereas melioidosis cases are distributed in a densely populated district in the southeast. We hypothesized that contaminated cropped fields generated aerosols contaminated with B. pseudomallei, which were carried by a northwesterly wind to the densely populated southeastern district. We collected soil and aerosol samples from a 72 km2 area of land, including the melioidosis-clustered area and its surroundings. Aerosols that contained B. pseudomallei-specific TTSS (type III secretion system) ORF2 DNA were well distributed in the endemic area but were rare in the surrounding areas during the rainy season. The concentration of this specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind. Moreover, the isolation rate in the superficial layers of the contaminated cropped field in the northwest was correlated with PCR positivity for aerosols collected from the southeast over a 2-year period. According to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, PFGE Type Ia (ST58) was the predominant pattern linking the molecular association among soil, aerosol and human isolates. Thus, the airborne transmission of melioidosis moves from the contaminated soil to aerosols and/or to humans in this endemic area. PMID:26061639

  2. Airborne infection control in India: Baseline assessment of health facilities

    PubMed Central

    Parmar, Malik M.; Sachdeva, K.S.; Rade, Kiran; Ghedia, Mayank; Bansal, Avi; Nagaraja, Sharath Burugina; Willis, Matthew D.; Misquitta, Dyson P.; Nair, Sreenivas A.; Moonan, Patrick K.; Dewan, Puneet K.

    2016-01-01

    Background Tuberculosis transmission in health care settings represents a major public health problem. In 2010, national airborne infection control (AIC) guidelines were adopted in India. These guidelines included specific policies for TB prevention and control in health care settings. However, the feasibility and effectiveness of these guidelines have not been assessed in routine practice. This study aimed to conduct baseline assessments of AIC policies and practices within a convenience sample of 35 health care settings across 3 states in India and to assess the level of implementation at each facility after one year. Method A multi-agency, multidisciplinary panel of experts performed site visits using a standardized risk assessment tool to document current practices and review resource capacity. At the conclusion of each assessment, facility-specific recommendations were provided to improve AIC performance to align with national guidelines. Result Upon initial assessment, AIC systems were found to be poorly developed and implemented. Administrative controls were not commonly practiced and many departments needed renovation to achieve minimum environmental standards. One year after the baseline assessments, there were substantial improvements in both policy and practice. Conclusion A package of capacity building and systems development that followed national guidelines substantially improved implementation of AIC policies and practice. PMID:26970461

  3. Airborne asbestos take-home exposures during handling of chrysotile-contaminated clothing following simulated full shift workplace exposures.

    PubMed

    Sahmel, Jennifer; Barlow, Christy A; Gaffney, Shannon; Avens, Heather J; Madl, Amy K; Henshaw, John; Unice, Ken; Galbraith, David; DeRose, Gretchen; Lee, Richard J; Van Orden, Drew; Sanchez, Matthew; Zock, Matthew; Paustenbach, Dennis J

    2016-01-01

    The potential for para-occupational, domestic, or take-home exposures from asbestos-contaminated work clothing has been acknowledged for decades, but historically has not been quantitatively well characterized. A simulation study was performed to measure airborne chrysotile concentrations associated with laundering of contaminated clothing worn during a full shift work day. Work clothing fitted onto mannequins was exposed for 6.5 h to an airborne concentration of 11.4 f/cc (PCME) of chrysotile asbestos, and was subsequently handled and shaken. Mean 5-min and 15-min concentrations during active clothes handling and shake-out were 3.2 f/cc and 2.9 f/cc, respectively (PCME). Mean airborne PCME concentrations decreased by 55% 15 min after clothes handling ceased, and by 85% after 30 min. PCM concentrations during clothes handling were 11-47% greater than PCME concentrations. Consistent with previously published data, daily mean 8-h TWA airborne concentrations for clothes-handling activity were approximately 1.0% of workplace concentrations. Similarly, weekly 40-h TWAs for clothes handling were approximately 0.20% of workplace concentrations. Estimated take-home cumulative exposure estimates for weekly clothes handling over 25-year working durations were below 1 f/cc-year for handling work clothes contaminated in an occupational environment with full shift airborne chrysotile concentrations of up to 9 f/cc (8-h TWA).

  4. Initial assessment of an airborne Ku-band polarimetric SAR.

    SciTech Connect

    Raynal, Ann Marie; Doerry, Armin Walter

    2013-02-01

    Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940s. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analysts understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.

  5. Retrospective exposure assessment to airborne asbestos among power industry workers

    PubMed Central

    2010-01-01

    Background A method of individually assessing former exposure to asbestos fibres is a precondition of risk-differentiated health surveillance. The main aims of our study were to assess former levels of airborne asbestos exposure in the power industry in Germany and to propose a basic strategy for health surveillance and the early detection of asbestos related diseases. Methods Between March 2002 and the end of 2006, we conducted a retrospective questionnaire based survey of occupational tasks and exposures with airborne asbestos fibres in a cohort of 8632 formerly asbestos exposed power industry workers. The data on exposure and occupation were entered into a specially designed computer programme, based on ambient monitoring of airborne asbestos fibre concentrations. The cumulative asbestos exposure was expressed as the product of the eight-hour time weighted average and the total duration of exposure in fibre years (fibres/cubic centimetre-years). Results Data of 7775 (90% of the total) participants working in installations for power generation, power distribution or gas supply could be evaluated. The power generation group (n = 5284) had a mean age of 56 years, were exposed for 20 years and had an average cumulative asbestos exposure of 42 fibre years. The occupational group of "metalworkers" (n = 1600) had the highest mean value of 79 fibre years. The corresponding results for the power distribution group (n = 2491) were a mean age of 45 years, a mean exposure duration of 12 years and an average cumulative asbestos exposure of only 2.5 fibre years. The gas supply workers (n = 512) had a mean age of 54 years and a mean duration of exposure of 15 years. Conclusions While the surveyed cohort as a whole was heavily exposed to asbestos dust, the power distribution group had a mean cumulative exposure of only 6% of that found in the power generation group. Based on the presented data, risk-differentiated disease surveillance focusing on metalworkers and electricians

  6. Space station contamination study: Assessment of contaminant spectral brightness

    NASA Technical Reports Server (NTRS)

    Torr, D. G.

    1988-01-01

    The assessment of spectral brightness resulting from the ambient-contaminant interaction requires a knowledge of the details of cross sections and excitation mechanisms. The approach adopted was to utilize the spectral brightness measurements made on Spacelab 1 and on the S3-4 spacecraft to identify source mechanisms, key cross sections and hence, the abundance of contaminant species. These inferred abundances were then used to update the composition comprising the total column concentrations predicted by the Science and Engineering Associates' configuration contamination model for the Space Station and to scale the irradiances to four altitudes: 300, 350, 400, and 463 km. The concentration irradiances are compared with zodiacal natural background levels. The results demonstrate that emissive contamination is significantly more severe than anticipated. It is shown that spectral emissions can become competitive with the zodiacal background up to altitudes as high as 400 km for the vacuum ultraviolet and visible emissions.

  7. 78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment... members of the Armed Forces to toxic airborne chemicals and fumes caused by open burn pits. DATES: Written...: cynthia.harvey-pryor@va.gov . Please refer to ``OMB Control No. 2900-NEW, Open Burn Pit Registry...

  8. Bioassay for assessing marine contamination

    SciTech Connect

    Lapota, D.; Copeland, H.; Mastny, G.; Rosenberger, D.; Duckworth, D.

    1996-03-01

    The Qwiklite bioassay, developed by the laboratory at NCCOSC, is used as a biological tool to gauge the extent of environmental contamination. Some species of marine phytoplankton produce bioluminescence. The Qwiklite bioassay determines acute response and chronic effects of a wide variety of toxicants upon bioluminescent dinotlagellates by measuring their light output after exposure.

  9. Deposition and accumulation of airborne organic contaminants in Yosemite National Park, Calfornia

    USGS Publications Warehouse

    Mast, Alisa M.; Alvarez, David A.; Zaugg, Steven D.

    2012-01-01

    Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub-parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms.

  10. Deposition and accumulation of airborne organic contaminants in Yosemite National Park, California.

    PubMed

    Mast, M Alisa; Alvarez, David A; Zaugg, Steven D

    2012-03-01

    Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub-parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms.

  11. Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

    PubMed

    Flynn, M R; Gatano, B L; McKernan, J L; Dunn, K H; Blazicko, B A; Carlton, G N

    1999-01-01

    This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters. PMID:10028895

  12. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

    The heating, ventilating, and air conditioning (HVAC) systems in older buildings often do not adequately handle air-borne contaminants. Outlines a three-stage Indoor Air Quality (IAQ) assessment and describes a case in point at a Pittsburgh, Pennsylvania, school. (MLF)

  13. Assessment of lightweight mobile nuclear power systems. [for airborne vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Rom, F. E.

    1973-01-01

    A review was made of lightweight mobile nuclear power systems (LMNPS). Data cover technical feasibility studies of LMNPS and airborne vehicles, mission studies, and non-technical conditions that are required to develop and use LMNPS.

  14. Pollution Characteristics and Health Risk Assessment of Airborne Heavy Metals Collected from Beijing Bus Stations.

    PubMed

    Zheng, Xiaoxia; Zhao, Wenji; Yan, Xing; Shu, Tongtong; Xiong, Qiulin; Chen, Fantao

    2015-08-17

    Airborne dust, which contains high levels of toxic metals, is recognized as one of the most harmful environment component. The purpose of this study was to evaluate heavy metals pollution in dustfall from bus stations in Beijing, and to perform a risk assessment analysis for adult passengers. The concentrations of Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The spatial distribution, pollution level and potential health risk of heavy metals were analyzed by Geographic Information System (GIS) mapping technology, geo-accumulation index and health risk assessment model, respectively. The results indicate that dust samples have elevated metal concentrations, especially for Cd, Cu, Pb and Zn. The nine metals can be divided into two categories in terms of spatial distribution and pollution level. Cd, Cr, Cu, Mo, Pb and Zn reach contaminated level and have similar spatial patterns with hotspots distributed within the Fifth Ring Road. While the hot spot areas of Co and V are always out of the Fifth Ring Road. Health risk assessment shows that both carcinogenic and non-carcinogenic risks of selected metals were within the safe range.

  15. Pollution Characteristics and Health Risk Assessment of Airborne Heavy Metals Collected from Beijing Bus Stations

    PubMed Central

    Zheng, Xiaoxia; Zhao, Wenji; Yan, Xing; Shu, Tongtong; Xiong, Qiulin; Chen, Fantao

    2015-01-01

    Airborne dust, which contains high levels of toxic metals, is recognized as one of the most harmful environment component. The purpose of this study was to evaluate heavy metals pollution in dustfall from bus stations in Beijing, and to perform a risk assessment analysis for adult passengers. The concentrations of Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The spatial distribution, pollution level and potential health risk of heavy metals were analyzed by Geographic Information System (GIS) mapping technology, geo-accumulation index and health risk assessment model, respectively. The results indicate that dust samples have elevated metal concentrations, especially for Cd, Cu, Pb and Zn. The nine metals can be divided into two categories in terms of spatial distribution and pollution level. Cd, Cr, Cu, Mo, Pb and Zn reach contaminated level and have similar spatial patterns with hotspots distributed within the Fifth Ring Road. While the hot spot areas of Co and V are always out of the Fifth Ring Road. Health risk assessment shows that both carcinogenic and non-carcinogenic risks of selected metals were within the safe range. PMID:26287229

  16. Assessment of the probability of contaminating Mars

    NASA Technical Reports Server (NTRS)

    Judd, B. R.; North, D. W.; Pezier, J. P.

    1974-01-01

    New methodology is proposed to assess the probability that the planet Mars will by biologically contaminated by terrestrial microorganisms aboard a spacecraft. Present NASA methods are based on the Sagan-Coleman formula, which states that the probability of contamination is the product of the expected microbial release and a probability of growth. The proposed new methodology extends the Sagan-Coleman approach to permit utilization of detailed information on microbial characteristics, the lethality of release and transport mechanisms, and of other information about the Martian environment. Three different types of microbial release are distinguished in the model for assessing the probability of contamination. The number of viable microbes released by each mechanism depends on the bio-burden in various locations on the spacecraft and on whether the spacecraft landing is accomplished according to plan. For each of the three release mechanisms a probability of growth is computed, using a model for transport into an environment suited to microbial growth.

  17. ASSESSING ALLERGENICITY OF INDOOR AIR FUNGAL CONTAMINANTS

    EPA Science Inventory

    Assessing Allergenicity of Indoor Air Fungal Contaminants
    M D W Ward1, M E Viana2, N Haykal-Coates1, L B Copeland1, S H Gavett1, and MJ K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, CVM, Raleigh, NC, USA.
    Rationale: The indoor environment has increased in impor...

  18. Crop water-stress assessment using an airborne thermal scanner

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Jackson, R. D.; Reginato, R. J.; Idso, S. B.; Goettelman, R. C.

    1978-01-01

    An airborne thermal scanner was used to measure the temperature of a wheat crop canopy in Phoenix, Arizona. The results indicate that canopy temperatures acquired about an hour and a half past solar noon were well correlated with presunrise plant water tension, a parameter directly related to plant growth and development. Pseudo-colored thermal images reading directly in stress degree days, a unit indicative of crop irrigation needs and yield potential, were produced. The aircraft data showed significant within-field canopy temperature variability, indicating the superiority of the synoptic view provided by aircraft over localized ground measurements. The standard deviation between airborne and ground-acquired canopy temperatures was 2 C or less.

  19. beta-(1,3)-Glucan exposure assessment by passive airborne dust sampling and new sensitive immunoassays.

    PubMed

    Noss, Ilka; Wouters, Inge M; Bezemer, Gillina; Metwali, Nervana; Sander, Ingrid; Raulf-Heimsoth, Monika; Heederik, Dick J J; Thorne, Peter S; Doekes, Gert

    2010-02-01

    Associations between house dust-associated beta-(1,3)-glucan exposure and airway inflammatory reactions have been reported, while such exposures in early childhood have been suggested to protect against asthma and wheezing. Most epidemiological studies have used reservoir dust samples and an inhibition enzyme immunoassay (EIA) for beta-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne beta-(1,3)-glucans in low-exposure environments, like homes. Specificities of available anti-beta-(1,3)-glucan antibodies were defined by direct and inhibition experiments. Three suitable antibody combinations were selected for sandwich EIAs. beta-(1,3)-Glucans in passive airborne dust collected with an electrostatic dust fall collector (EDC) and floor dust from seven homes were measured with the three EIAs. Floor dust samples were additionally analyzed in the inhibition EIA. The sandwich EIAs were sensitive enough for airborne glucan measurement and showed different specificities for commercial glucans, while the beta-(1,3)-glucan levels in house dust samples correlated strongly. The feasibility of measuring glucans in airborne dust with the recently introduced EDC method was further investigated by selecting the most suitable of the three EIAs to measure and compare beta-(1,3)-glucan levels in the EDC and in floor and actively collected airborne dust samples of the previously performed EDC validation study. The EDC beta-(1,3)-glucan levels correlated moderately with beta-(1,3)-glucans in actively collected airborne dust and floor dust samples, while the glucan levels in the airborne dust and floor dust samples did not correlate. The combination of the newly developed beta-(1,3)-glucan sandwich EIA with EDC sampling now allows assessment in large-scale population studies of exposure to airborne beta-(1,3)-glucans in homes or other low-exposure environments.

  20. Airborne Topographic Mapper Calibration Procedures and Accuracy Assessment

    NASA Technical Reports Server (NTRS)

    Martin, Chreston F.; Krabill, William B.; Manizade, Serdar S.; Russell, Rob L.; Sonntag, John G.; Swift, Robert N.; Yungel, James K.

    2012-01-01

    Description of NASA Airborn Topographic Mapper (ATM) lidar calibration procedures including analysis of the accuracy and consistancy of various ATM instrument parameters and the resulting influence on topographic elevation measurements. The ATM elevations measurements from a nominal operating altitude 500 to 750 m above the ice surface was found to be: Horizontal Accuracy 74 cm, Horizontal Precision 14 cm, Vertical Accuracy 6.6 cm, Vertical Precision 3 cm.

  1. Assess program: Interactive data management systems for airborne research

    NASA Technical Reports Server (NTRS)

    Munoz, R. M.; Reller, J. O., Jr.

    1974-01-01

    Two data systems were developed for use in airborne research. Both have distributed intelligence and are programmed for interactive support among computers and with human operators. The C-141 system (ADAMS) performs flight planning and telescope control functions in addition to its primary role of data acquisition; the CV-990 system (ADDAS) performs data management functions in support of many research experiments operating concurrently. Each system is arranged for maximum reliability in the first priority function, precision data acquisition.

  2. The impact of flood and post-flood cleaning on airborne microbiological and particle contamination in residential houses.

    PubMed

    He, Congrong; Salonen, Heidi; Ling, Xuan; Crilley, Leigh; Jayasundara, Nadeesha; Cheung, Hing Cho; Hargreaves, Megan; Huygens, Flavia; Knibbs, Luke D; Ayoko, Godwin A; Morawska, Lidia

    2014-08-01

    In January 2011, Brisbane, Australia, experienced a major river flooding event. We aimed to investigate its effects on air quality and assess the role of prompt cleaning activities in reducing the airborne exposure risk. A comprehensive, multi-parameter indoor and outdoor measurement campaign was conducted in 41 residential houses, 2 and 6 months after the flood. The median indoor air concentrations of supermicrometer particle number (PN), PM10, fungi and bacteria 2 months after the flood were comparable to those previously measured in Brisbane. These were 2.88 p cm(-3), 15 μg m(-3), 804 cf um(-3) and 177 cf um(-3) for flood-affected houses (AFH), and 2.74 p cm(-3), 15 μg m(-3), 547 cf um(-3) and 167 cf um(-3) for non-affected houses (NFH), respectively. The I/O (indoor/outdoor) ratios of these pollutants were 1.08, 1.38, 0.74 and 1.76 for AFH and 1.03, 1.32, 0.83 and 2.17 for NFH, respectively. The average of total elements (together with transition metals) in indoor dust was 2296 ± 1328 μg m(-2) for AFH and 1454 ± 678 μg m(-2) for NFH, respectively. In general, the differences between AFH and NFH were not statistically significant, implying the absence of a measureable effect on air quality from the flood. We postulate that this was due to the very swift and effective cleaning of the flooded houses by 60,000 volunteers. Among the various cleaning methods, the use of both detergent and bleach was the most efficient at controlling indoor bacteria. All cleaning methods were equally effective for indoor fungi. This study provides quantitative evidence of the significant impact of immediate post-flood cleaning on mitigating the effects of flooding on indoor bioaerosol contamination and other pollutants.

  3. Experimental investigation of airborne contaminant transport by a human wake moving in a ventilated aircraft cabin

    NASA Astrophysics Data System (ADS)

    Poussou, Stephane B.

    The air ventilation system in jetliners provides a comfortable and healthy environment for passengers. Unfortunately, the increase in global air traffic has amplified the risks presented by infectious aerosols or noxious material released during flight. Inside the cabin, air typically flows continuously from overhead outlets into sidewall exhausts in a circular pattern that minimizes secondary flow between adjacent seat rows. However, disturbances frequently introduced by individuals walking along an aisle may alter air distribution, and contribute to spreading of contaminants. Numerical simulation of these convoluted transient flow phenomena is difficult and complex, and experimental assessment of contaminant distribution in real cabins often impractical. A fundamental experimental study was undertaken to examine the transport phenomena, to validate computations and to improve air monitoring systems. A finite moving body was modeled in a 10:1 scale simplified aircraft cabin equipped with ventilation, at a Reynolds number (based on body diameter) of the order of 10,000. An experimental facility was designed and constructed to permit measurements of the ventilation and wake velocity fields using particle image velocimetry (PIV). Contaminant migration was imaged using the planar laser induced fluorescence (PLIF) technique. The effect of ventilation was estimated by comparison with a companion baseline study. Results indicate that the evolution of a downwash predominant behind finite bodies of small aspect ratio is profoundly perturbed by the ventilation flow. The reorganization of vortical structures in the near-wake leads to a shorter longitudinal recirculation region. Furthermore, mixing in the wake is modified and contaminant is observed to convect to higher vertical locations corresponding to seated passenger breathing level.

  4. Assessment of airborne microorganisms by real-time PCR: optimistic findings and research challenges.

    PubMed

    Oppliger, Anne; Masclaux, Frederic G; Niculita-Hirzel, Helene

    2011-01-01

    Most airborne microorganisms are natural components of our ecosystem. Soil, vegetation and animals, including humans, are sources for aerial release of these living or dead cells. In the past, assessment of airborne microorganisms was mainly restricted to occupational health concerns. Indeed, in several occupations, exposure to very high concentrations of non-infectious airborne bacteria and fungi, result in allergenic, toxic or irritant reactions. Recently, the threat of bioterrorism and pandemics have highlighted the urgent need to increase knowledge of bioaerosol ecology. More fundamentally, airborne bacterial and fungal communities begin to draw much more consideration from environmental microbiologists, who have neglected this area for a long time. This increased interest of scientists is to a great part due to the development and use of real-time PCR techniques to identify and quantify airborne microorganisms. Even if the advantages of the PCR technology are obvious, researchers are confronted with new problems. This review describes the methodological state of the art in bioaerosols field and emphasizes the future challenges and perspectives of the real-time PCR-based methods for airborne microorganism studies. PMID:21196388

  5. Ecological risk assessment of contaminated soil.

    PubMed

    Jensen, John; Pedersen, Marianne Bruus

    2006-01-01

    This review has described three cases of ecological risk assessment. The cases include two heavy metals (Cu and Zn) and an anthropogenic organic chemical (DDT). It concludes that there are at least two major constraints hampering the use of laboratory tests to predict effects under natural field conditions. One key issue is bioavailability, and another is suboptimal conditions or multiple stresses in the field such as climatic stress (drought, frost), predators, competition, or food shortage. On the basis of the presented case studies, it was possible to answer three essential questions often raised in connection to ecological risk assessment of contaminated sites. 1. To what extend does soil screening level (SSL) estimate the risk? The SSL are generally derived at levels corresponding to the lowest observed effect levels in laboratory studies, which often is close to the background levels found in many soils. In the cases of zinc and especially DDT, the SSL seemed quite conservative, whereas for copper they resemble the level at which changes in the community structure of soil microarthropods and the plant community have been observed at contaminated sites. The SSL correspond as a whole relatively well with concentrations where no effects or only minor effects were observed in controlled field studies. However, large variation in field surveys can often make it difficult to conclude to what extent the SSL corresponded to no-effect levels in the field. 2. Do bioassays represent a more realistic risk estimate? Here, there is no firm conclusion. The zinc study in UK showed a better relationship between the outcome of ex situ bioassays and field observations than the SSL. The latter overestimated the risk compared to field observations. However, this would be species dependent, as the sensitivity to metals may vary considerably between recognized test species, even within the same group of organisms, such as Folsomia candida and Folsomia fimetaria or Eisenia fetida

  6. Preliminary Assessment of Operational Hazards and Safety Requirements for Airborne Trajectory Management (ABTM) Roadmap Applications

    NASA Technical Reports Server (NTRS)

    Cotton, William B.; Hilb, Robert; Koczo, Stefan, Jr.; Wing, David J.

    2016-01-01

    A set of five developmental steps building from the NASA TASAR (Traffic Aware Strategic Aircrew Requests) concept are described, each providing incrementally more efficiency and capacity benefits to airspace system users and service providers, culminating in a Full Airborne Trajectory Management capability. For each of these steps, the incremental Operational Hazards and Safety Requirements are identified for later use in future formal safety assessments intended to lead to certification and operational approval of the equipment and the associated procedures. Two established safety assessment methodologies that are compliant with the FAA's Safety Management System were used leading to Failure Effects Classifications (FEC) for each of the steps. The most likely FEC for the first three steps, Basic TASAR, Digital TASAR, and 4D TASAR, is "No effect". For step four, Strategic Airborne Trajectory Management, the likely FEC is "Minor". For Full Airborne Trajectory Management (Step 5), the most likely FEC is "Major".

  7. Performance assessment of MEMS adaptive optics in tactical airborne systems

    NASA Astrophysics Data System (ADS)

    Tyson, Robert K.

    1999-09-01

    Tactical airborne electro-optical systems are severely constrained by weight, volume, power, and cost. Micro- electrical-mechanical adaptive optics provide a solution that addresses the engineering realities without compromising spatial and temporal compensation requirements. Through modeling and analysis, we determined that substantial benefits could be gained for laser designators, ladar, countermeasures, and missile seekers. The developments potential exists for improving seeker imagery resolution 20 percent, extending countermeasures keep-out range by a factor of 5, doubling the range for ladar detection and identification, and compensating for supersonic and hypersonic aircraft boundary layers. Innovative concepts are required for atmospheric pat hand boundary layer compensation. We have developed design that perform these tasks using high speed scene-based wavefront sensing, IR aerosol laser guide stars, and extended-object wavefront beacons. We have developed a number of adaptive optics system configurations that met the spatial resolution requirements and we have determined that sensing and signal processing requirements can be met. With the help of micromachined deformable mirrors and sensor, we will be able to integrate the systems into existing airborne pods and missiles as well as next generation electro-optical systems.

  8. Assessment of Airborne Particles. Fundamentals, Applications, and Implications to Inhalation Toxicity.

    ERIC Educational Resources Information Center

    Mercer, Thomas T., Ed.; And Others

    Concern over chemical and radioactive particulate matter in industry and over rapidly increasing air pollution has stimulated research both on the properties of airborne particles and methods for assessing them and on their biological effects following inhalation. The Third Rochester International Conference on Environmental Toxicity was,…

  9. EVALUATION OF BIOAEROSOL COMPONENTS, GENERATION FACTORS, AND AIRBORNE TRANSPORT ASSOCIATED WITH LIME TREATMENT OF CONTAMINATED SEDIMENT

    EPA Science Inventory

    Lime treatment has been used in contaminated sediment management activities for many purposes such as dewatering, improvement of physical properties, and reducing contaminant mobility. Exothermic volatilization of volatile organic compounds from lime-treated sediment is well kno...

  10. Implications of uncertainty in exposure assessment for groundwater contamination

    USGS Publications Warehouse

    Reichard, Eric G.; Izbicki, John A.; Martin, Peter

    1995-01-01

    Decision-making on regulation, mitigation, and treatment of drinking water contamination depends, in part, on estimates of human exposure. Assessment of past, present and potential future exposure levels requires quantitative characterization of the contaminant sources, the transport of contaminants and the level of actual human exposure to the contaminated water. Failure to consider the uncertainties in these three components of exposure assessment can lead to poor decisions such as implementing an inappropriate mitigation strategy or failing to regulate an important contaminant. Three examples from US Geological Survey hydrogeologic studies in southern California are presented to illustrate some of the unique uncertainties associated with exposure assessment for groundwater contamination.

  11. Geltape method for measurement of work related surface contamination with cobalt containing dust: correlation between surface contamination and airborne exposure.

    PubMed Central

    Poulsen, O M; Olsen, E; Christensen, J M; Vinzent, P; Petersen, O H

    1995-01-01

    OBJECTIVES--The geltape method is a new method for optical measurement of total amount of dust on surfaces. The objectives were to study the potential applicability of this method to measurements of work related cobalt exposure during painting of plates with cobalt dye. METHODS--Consecutive series of work related geltape prints were taken from surfaces inside and outside the ventilation cabins of two plate painters during two full working days. The amount of dust picked up by the geltapes was measured optically with a field monitor. Also, personal air samples were collected on filters at the different work processes. In the laboratory the contents of cobalt on the geltape prints and the filters were measured with inductive coupled plasma atomic emission spectroscopy. RESULTS--The key results were: (a) when the geltape prints were taken from surfaces inside the cabins the optically measured area of the geltapes covered with total dust (area (%)) correlated well with the chemically measured amount of cobalt present on the geltapes. Linear correlation coefficient (R2) was 0.91 for geltape prints taken on the floor and 0.94 for prints taken on the ceiling; (b) the cumulative airborne cobalt exposure, calculated from data on work related exposure by personal sampling, correlated with the area (%) of geltape prints taken from the ceiling of the cabin (R2 = 0.98); (c) the geltape method could be used to distinguish both between work processes with different levels of cobalt exposure, and between plate painters subjected to significant differences in airborne cobalt exposure. CONCLUSION--The geltape method could produce measures of the work related exposures as well as whole day exposure for cobalt. The geltape results correlated with measurements of personal airborne cobalt exposure. In this industry the profile of exposure is well-defined in time, and it seems reasonable to apply this fast and low cost method in routine exposure surveillance to obtain a more detailed

  12. Ecological risk assessment of contaminated soil.

    PubMed

    Jensen, John; Pedersen, Marianne Bruus

    2006-01-01

    This review has described three cases of ecological risk assessment. The cases include two heavy metals (Cu and Zn) and an anthropogenic organic chemical (DDT). It concludes that there are at least two major constraints hampering the use of laboratory tests to predict effects under natural field conditions. One key issue is bioavailability, and another is suboptimal conditions or multiple stresses in the field such as climatic stress (drought, frost), predators, competition, or food shortage. On the basis of the presented case studies, it was possible to answer three essential questions often raised in connection to ecological risk assessment of contaminated sites. 1. To what extend does soil screening level (SSL) estimate the risk? The SSL are generally derived at levels corresponding to the lowest observed effect levels in laboratory studies, which often is close to the background levels found in many soils. In the cases of zinc and especially DDT, the SSL seemed quite conservative, whereas for copper they resemble the level at which changes in the community structure of soil microarthropods and the plant community have been observed at contaminated sites. The SSL correspond as a whole relatively well with concentrations where no effects or only minor effects were observed in controlled field studies. However, large variation in field surveys can often make it difficult to conclude to what extent the SSL corresponded to no-effect levels in the field. 2. Do bioassays represent a more realistic risk estimate? Here, there is no firm conclusion. The zinc study in UK showed a better relationship between the outcome of ex situ bioassays and field observations than the SSL. The latter overestimated the risk compared to field observations. However, this would be species dependent, as the sensitivity to metals may vary considerably between recognized test species, even within the same group of organisms, such as Folsomia candida and Folsomia fimetaria or Eisenia fetida

  13. Estimation and assessment of Mars contamination.

    PubMed

    Debus, A

    2005-01-01

    respect to all types of contamination. Answering this question, will help to assess the potential effects of such contamination on scientific results and will address concerns relative to any ethical considerations about the contamination of other planets.

  14. Use of plants for biomonitoring of airborne mercury in contaminated areas.

    PubMed

    Lodenius, Martin

    2013-08-01

    Biological methods provide a wide variety of possibilities to monitor mercury pollution in the environment. E.g., mosses and lichens give a good picture of the spatial distribution of mercury around pollution sources. On regional or global scale the accuracy is smaller and interpretation of the results more difficult. One reason for this is the long life-time and low reactivity of gaseous elemental mercury (Hg(0)). At least temperature, light, concentration in air, speciation and biological factors affect the net deposition to or emission from vegetation. Different methods for estimating mercury fluxes between atmosphere and vegetation give different results. At contaminated sites the reaction types and fluxes most probably differ from those at uncontaminated sites. There are many pathways for mercury fluxes as well as physicochemical and biochemical reactions between different mercury species which makes it difficult to assess the fluxes in detail. Environmental conditions like temperature, light and humidity affect these fluxes. Compared to mechanical collectors biological monitors most probably give a more realistic picture of especially dry deposition but a lot of work has still to be done before we have accurate and reliable quantitative estimates of the deposition. PMID:23472606

  15. Applications of ion chromatography in the semiconductor industry. II. Determination of basic airborne contaminants in a cleanroom.

    PubMed

    Lue, S J; Huang, C

    1999-07-30

    Since the geometry of semiconductors and integrated circuits has been shrunk to well below sub-micron dimensions, there is a great demand for precise and reliable analytical techniques to measure and monitor the contaminants in all areas related to the fabrication process. Special concerns about the air cleanliness in a Fab lead to the necessity for developing analytical techniques to perform this task. In this research, basic airborne contaminants in a cleanroom were adsorbed onto a collection tube, subsequently extracted with deionized water and analyzed by ion chromatography. Such a method is capable of simultaneously measuring the concentrations of ammonia and cations (e.g., sodium, potassium, calcium, magnesium, etc.) present in the cleanroom air samples. The optimal sample preparation method was determined and the analyte concentrations at various locations in the cleanroom were measured. The results showed significant variations from one location to another. The long-term fluctuations in the contaminant levels were also significant. Data obtained using this method compared well with data from inductively coupled plasma analysis of the same materials.

  16. Data processing of remotely sensed airborne hyperspectral data using the Airborne Processing Library (APL): Geocorrection algorithm descriptions and spatial accuracy assessment

    NASA Astrophysics Data System (ADS)

    Warren, Mark A.; Taylor, Benjamin H.; Grant, Michael G.; Shutler, Jamie D.

    2014-03-01

    Remote sensing airborne hyperspectral data are routinely used for applications including algorithm development for satellite sensors, environmental monitoring and atmospheric studies. Single flight lines of airborne hyperspectral data are often in the region of tens of gigabytes in size. This means that a single aircraft can collect terabytes of remotely sensed hyperspectral data during a single year. Before these data can be used for scientific analyses, they need to be radiometrically calibrated, synchronised with the aircraft's position and attitude and then geocorrected. To enable efficient processing of these large datasets the UK Airborne Research and Survey Facility has recently developed a software suite, the Airborne Processing Library (APL), for processing airborne hyperspectral data acquired from the Specim AISA Eagle and Hawk instruments. The APL toolbox allows users to radiometrically calibrate, geocorrect, reproject and resample airborne data. Each stage of the toolbox outputs data in the common Band Interleaved Lines (BILs) format, which allows its integration with other standard remote sensing software packages. APL was developed to be user-friendly and suitable for use on a workstation PC as well as for the automated processing of the facility; to this end APL can be used under both Windows and Linux environments on a single desktop machine or through a Grid engine. A graphical user interface also exists. In this paper we describe the Airborne Processing Library software, its algorithms and approach. We present example results from using APL with an AISA Eagle sensor and we assess its spatial accuracy using data from multiple flight lines collected during a campaign in 2008 together with in situ surveyed ground control points.

  17. Marine Geoid Undulation Assessment Over South China Sea Using Global Geopotential Models and Airborne Gravity Data

    NASA Astrophysics Data System (ADS)

    Yazid, N. M.; Din, A. H. M.; Omar, K. M.; Som, Z. A. M.; Omar, A. H.; Yahaya, N. A. Z.; Tugi, A.

    2016-09-01

    Global geopotential models (GGMs) are vital in computing global geoid undulations heights. Based on the ellipsoidal height by Global Navigation Satellite System (GNSS) observations, the accurate orthometric height can be calculated by adding precise and accurate geoid undulations model information. However, GGMs also provide data from the satellite gravity missions such as GRACE, GOCE and CHAMP. Thus, this will assist to enhance the global geoid undulations data. A statistical assessment has been made between geoid undulations derived from 4 GGMs and the airborne gravity data provided by Department of Survey and Mapping Malaysia (DSMM). The goal of this study is the selection of the best possible GGM that best matches statistically with the geoid undulations of airborne gravity data under the Marine Geodetic Infrastructures in Malaysian Waters (MAGIC) Project over marine areas in Sabah. The correlation coefficients and the RMS value for the geoid undulations of GGM and airborne gravity data were computed. The correlation coefficients between EGM 2008 and airborne gravity data is 1 while RMS value is 0.1499.In this study, the RMS value of EGM 2008 is the lowest among the others. Regarding to the statistical analysis, it clearly represents that EGM 2008 is the best fit for marine geoid undulations throughout South China Sea.

  18. External induced contamination environment assessment for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Leger, Lubert; Ehlers, Horst; Hakes, Charles; Theall, Jeff; Soares, Carlos

    1993-01-01

    An assessment of the Space Station Freedom performance as affected by the external induced contamination environment is in progress. The assessment procedure involves comparing the Space Station Freedom external contamination requirements, SSP 30426, Revision B (1991), with calculated molecular deposition, molecular column density, and other effects from potential sources of contamination. The current assessment comprises discussions of Space Shuttle proximity operations, Space Shuttle waste-water dumps (while docked to the Space Station), Space Station fluid and waste-gas venting, system gas leakage, external material outgassing, and a combined contamination assessment. This performance assessment indicates that Space Station Freedom contamination requirements are realistic and can be satisfied when all contamination sources are included.

  19. Contamination assessment for OSSA space station IOC payloads

    NASA Technical Reports Server (NTRS)

    Chinn, S.; Gordon, T.; Rantanen, R.

    1987-01-01

    The results are presented from a study for the Space Station Planners Group of the Office of Space Sciences and Applications. The objectives of the study are: (1) the development of contamination protection requirements for protection of Space Station attached payloads, serviced payloads and platforms; and (2) the determination of unknowns or major impacts requiring further assessment. The nature, sources, and quantitative properties of the external contaminants to be encountered on the Station are summarized. The OSSA payload contamination protection requirements provided by the payload program managers are reviewed and the level of contamination awareness among them is discussed. Preparation of revisions to the contamination protection requirements are detailed. The comparative impact of flying the Station at constant atmospheric density rather than constant altitude is assessed. The impact of the transverse boom configuration of the Station on contamination is also assessed. The contamination protection guidelines which OSSA should enforce during their development of payloads are summarized.

  20. Bacterial contamination in a modern operating suite. 3. Importance of floor contamination as a source of airborne bacteria.

    PubMed Central

    Hambraeus, A.; Bengtsson, S.; Laurell, G.

    1978-01-01

    The redispersal factor for bacteria-carrying particles from a contaminated floor was determined after mopping, blowing and walking activity. Walking gave the highest redispersal factor, 3.5 X 10(-3) m-1, which was three times higher than for blowing and 17 times higher than for mopping. The mean die-away rate for the bacteria-carrying particles used was 1.9/h without ventilation and 14.3/h with ventilation. It was calculated that in the operating rooms less than 15% of the bacteria found in the air were redispersed floor bacteria. PMID:632559

  1. Sampling and chemical characterization of workplace atmospheres contaminated with airborne diesel exhaust

    SciTech Connect

    Jenkins, R.A.; Griest, W.H.; Moneyhun, J.H.; Tomkins, B.A.; Ilgner, R.H.; Higgins, C.E.; Gayle, T.M.

    1988-01-01

    The chemical composition of workplace atmospheres contaminated with diesel exhaust appear to be exceedingly complex. Building to building differences occur even though the fuel source for vehicles operating in such a facility are identical. There appear to be substantial differences between the particle size distributions of workplace atmospheres and that of those sources which contaminate them. Long duration sampling tends to alter the apparent composition of the collected particle phase, and composite samples of shorter duration may enhance compositional accuracy. Diluted idling large vehicle engine exhaust is probably not a compositionally accurate surrogate for workplace atmospheres for inhalation toxicology studies.

  2. Comparison of High and Low Density Airborne LIDAR Data for Forest Road Quality Assessment

    NASA Astrophysics Data System (ADS)

    Kiss, K.; Malinen, J.; Tokola, T.

    2016-06-01

    Good quality forest roads are important for forest management. Airborne laser scanning data can help create automatized road quality detection, thus avoiding field visits. Two different pulse density datasets have been used to assess road quality: high-density airborne laser scanning data from Kiihtelysvaara and low-density data from Tuusniemi, Finland. The field inventory mainly focused on the surface wear condition, structural condition, flatness, road side vegetation and drying of the road. Observations were divided into poor, satisfactory and good categories based on the current Finnish quality standards used for forest roads. Digital Elevation Models were derived from the laser point cloud, and indices were calculated to determine road quality. The calculated indices assessed the topographic differences on the road surface and road sides. The topographic position index works well in flat terrain only, while the standardized elevation index described the road surface better if the differences are bigger. Both indices require at least a 1 metre resolution. High-density data is necessary for analysis of the road surface, and the indices relate mostly to the surface wear and flatness. The classification was more precise (31-92%) than on low-density data (25-40%). However, ditch detection and classification can be carried out using the sparse dataset as well (with a success rate of 69%). The use of airborne laser scanning data can provide quality information on forest roads.

  3. Airborne concentrations of trivalent and hexavalent chromium from contaminated soils at unpaved and partially paved commercial/industrial sites

    SciTech Connect

    Falerios, M.; Schild, K. ); Sheehan, P.; Paustenbach, D.J. )

    1992-01-01

    This method described was used to quantify airborne Cr(VI) levels at both indoor and outdoor locations at 21 sites in Hudson County, New Jersey which have soils containing chromite ore processing residue. Of the 21 sites evaluated, nine were unpaved or partially paved industrial/commercial sites or roadways with a moderate to high level of heavy truck traffic. Most of the remainder were commercial facilities with partially paved or unpaved parking lots and only light vehicle traffic. In addition, 15 residential sites in the area which do not have contaminated soil were sampled to characterized background levels of Cr(VI). The overall arithmetic mean values for indoor and outdoor Cr(VI) in total suspended particulates at the 12 industrial sites were 3.0 ng/m{sup 3} and 9.9ng/m{sup 3}, respectively. The indoor Cr(VI) concentrations measured at the 15 residential sites ranged from 0.38 to 3.3 ng/m{sup 3}. Airborne Cr(VI) levels outdoors at sites with chromite ore residue appear to be primarily influenced by the level of local vehicle traffic. Measured outdoor concentrations at sites with light vehicle traffic were generally low, within the range of levels measured indoors at the residential sites, and not strongly influenced by Cr(VI) concentrations in surface soils. At sites with a high rate of vehicle traffic, outdoor Cr(VI) concentrations exceeded background levels only on days when surface soils were dry. The average concentrations measured at these sites were more than 5,000-times lower than the current occupational exposure limit for Cr(VI) (TLV = 0.05 mg/m{sup 3}).

  4. Payload/orbiter contamination control assessment support

    NASA Technical Reports Server (NTRS)

    Rantanen, R. O.; Ress, E. B.

    1975-01-01

    The development and use is described of a basic contamination mathematical model of the shuttle orbiter which incorporates specific shuttle orbiter configurations and contamination sources. These configurations and sources were evaluated with respect to known shuttle orbiter operational surface characteristics and specific lines-of-sight which encompass the majority of viewing requirements for shuttle payloads. The results of these evaluations are presented as summary tables for each major source. In addition, contamination minimization studies were conducted and recommendations are made, where applicable, to support the shuttle orbiter design and operational planning for those sources which were identified to present a significant contamination threat.

  5. Assessment of hot gas contaminant control

    SciTech Connect

    Rutkowski, M.D.; Klett, M.G.; Zaharchuk, R.

    1996-12-31

    The objective of this work is to gather data and information to assist DOE in responding to the NRC recommendation on hot gas cleanup by performing a comprehensive assessment of hot gas cleanup systems for advanced coal-based Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) including the status of development of the components of the hot gas cleanup systems, and the probable cost and performance impacts. The scope and time frame of information gathering is generally responsive to the boundaries set by the National Research council (NRC), but includes a broad range of interests and programs which cover hot gas cleanup through the year 2010. As the status of hot gas cleanup is continually changing, additional current data and information are being obtained for this effort from this 1996 METC Contractors` Review Meeting as well as from the 1996 Pittsburgh Coal Conference, and the University of Karlsruhe Symposium. The technical approach to completing this work consists of: (1) Determination of the status of hot gas cleanup technologies-- particulate collection systems, hot gas desulfurization systems, and trace contaminant removal systems; (2) Determination of hot gas cleanup systems cost and performance sensitivities. Analysis of conceptual IGCC and PFBC plant designs with hot gas cleanup have been performed. The impact of variations in hot gas cleanup technologies on cost and performance was evaluated using parametric analysis of the baseline plant designs and performance sensitivity.

  6. DISTRIBUTIONS OF AIRBORNE AGRICULTURAL CONTAMINANTS RELATIVE TO AMPHIBIAN POPULATIONS IN THE SOUTHERN SIERRA NEVADA, CA

    EPA Science Inventory

    The Sierra Nevada mountain range lies adjacent to one of the heaviest pesticide use areas in the USA, the Central Valley of California. Because of this proximity, concern has arisen that agricultural pesticides, in addition to other contaminants, are adversely affecting the natur...

  7. Space station contamination study: Assessment of contaminant spectral brightness

    NASA Technical Reports Server (NTRS)

    Torr, D. G.

    1990-01-01

    The results presented show that spectral emissions which arise as a result of vehicle-ambient atmospheric interactions are significant and can become competitive with the natural zodiacal background up to altitudes as high as 400 km for the Vacuun Ultraviolet (VUV) and Visible Infrared Spectra (VIS) for the worst case conditions used. The empirical database on the induced environment of space vehicles is very sparse, and these results are based on a number of assumptions and cannot be regarded as definitive at the present time. Since the technique for doing calculations of this kind was developed in its preliminary form for the purpose of this study, a list of greatly improved estimates are provided of the contamination irradiances. Tasks which are considered most important in order to achieve a higher confidence level for the preliminary conclusions drawn are provided.

  8. Assessment of airborne exposure and dermal contact to acrylamide during chemical grouting operations. Final report

    SciTech Connect

    McHugh, J.M.

    1987-07-22

    Acrylamide exposure may occur by inhalation, ingestion and skin absorption; acrylamide is a neurotoxin and an irritant. The report details the results of field studies to assess airborne exposure and dermal contact to acrylamide during chemical grouting operations. Occupational exposures to acrylamide were characterized for sewer mainline, lateral line, and manhole maintenance operations. The objective of the study was to collect exposure data based on observations and measurements to be used as an integral part of a quantitative risk assessment by the U.S. Environmental Protection Agency's Office of Toxic Substances.

  9. [Quantitative method of representative contaminants in groundwater pollution risk assessment].

    PubMed

    Wang, Jun-Jie; He, Jiang-Tao; Lu, Yan; Liu, Li-Ya; Zhang, Xiao-Liang

    2012-03-01

    In the light of the problem that stress vulnerability assessment in groundwater pollution risk assessment is lack of an effective quantitative system, a new system was proposed based on representative contaminants and corresponding emission quantities through the analysis of groundwater pollution sources. And quantitative method of the representative contaminants in this system was established by analyzing the three properties of representative contaminants and determining the research emphasis using analytic hierarchy process. The method had been applied to the assessment of Beijing groundwater pollution risk. The results demonstrated that the representative contaminants hazards greatly depended on different research emphasizes. There were also differences between the sequence of three representative contaminants hazards and their corresponding properties. It suggested that subjective tendency of the research emphasis had a decisive impact on calculation results. In addition, by the means of sequence to normalize the three properties and to unify the quantified properties results would zoom in or out of the relative properties characteristic of different representative contaminants.

  10. Preliminary assessment of airborne imaging spectrometer and airborne thematic mapper data acquired for forest decline areas in the Federal Republic of Germany

    NASA Technical Reports Server (NTRS)

    Herrmann, Karin; Ammer, Ulrich; Rock, Barrett; Paley, Helen N.

    1988-01-01

    This study evaluated the utility of data collected by the high-spectral resolution airborne imaging spectrometer (AIS-2, tree mode, spectral range 0.8-2.2 microns) and the broad-band Daedalus airborne thematic mapper (ATM, spectral range 0.42-13.0 micron) in assessing forest decline damage at a predominantly Scotch pine forest in the FRG. Analysis of spectral radiance values from the ATM and raw digital number values from AIS-2 showed that higher reflectance in the near infrared was characteristic of high damage (heavy chlorosis, limited needle loss) in Scotch pine canopies. A classification image of a portion of the AIS-2 flight line agreed very well with a damage assessment map produced by standard aerial photointerpretation techniques.

  11. Modeling and performance assessment in QinetiQ of EO and IR airborne reconnaissance systems

    NASA Astrophysics Data System (ADS)

    Williams, John W.; Potter, Gary E.

    2002-11-01

    QinetiQ are the technical authority responsible for specifying the performance requirements for the procurement of airborne reconnaissance systems, on behalf of the UK MoD. They are also responsible for acceptance of delivered systems, overseeing and verifying the installed system performance as predicted and then assessed by the contractor. Measures of functional capability are central to these activities. The conduct of these activities utilises the broad technical insight and wide range of analysis tools and models available within QinetiQ. This paper focuses on the tools, methods and models that are applicable to systems based on EO and IR sensors. The tools, methods and models are described, and representative output for systems that QinetiQ has been responsible for is presented. The principle capability applicable to EO and IR airborne reconnaissance systems is the STAR (Simulation Tools for Airborne Reconnaissance) suite of models. STAR generates predictions of performance measures such as GRD (Ground Resolved Distance) and GIQE (General Image Quality) NIIRS (National Imagery Interpretation Rating Scales). It also generates images representing sensor output, using the scene generation software CAMEO-SIM and the imaging sensor model EMERALD. The simulated image 'quality' is fully correlated with the predicted non-imaging performance measures. STAR also generates image and table data that is compliant with STANAG 7023, which may be used to test ground station functionality.

  12. Assessing groundwater vulnerability to agrichemical contamination in the Midwest US

    USGS Publications Warehouse

    Burkart, M.R.; Kolpin, D.W.; James, D.E.

    1999-01-01

    Agrichemicals (herbicides and nitrate) are significant sources of diffuse pollution to groundwater. Indirect methods are needed to assess the potential for groundwater contamination by diffuse sources because groundwater monitoring is too costly to adequately define the geographic extent of contamination at a regional or national scale. This paper presents examples of the application of statistical, overlay and index, and process-based modeling methods for groundwater vulnerability assessments to a variety of data from the Midwest U.S. The principles for vulnerability assessment include both intrinsic (pedologic, climatologic, and hydrogeologic factors) and specific (contaminant and other anthropogenic factors) vulnerability of a location. Statistical methods use the frequency of contaminant occurrence, contaminant concentration, or contamination probability as a response variable. Statistical assessments are useful for defining the relations among explanatory and response variables whether they define intrinsic or specific vulnerability. Multivariate statistical analyses are useful for ranking variables critical to estimating water quality responses of interest. Overlay and index methods involve intersecting maps of intrinsic and specific vulnerability properties and indexing the variables by applying appropriate weights. Deterministic models use process-based equations to simulate contaminant transport and are distinguished from the other methods in their potential to predict contaminant transport in both space and time. An example of a one-dimensional leaching model linked to a geographic information system (GIS) to define a regional metamodel for contamination in the Midwest is included.

  13. The effect of temperature differences on the distribution of an airborne contaminant in an experimental room.

    PubMed

    Lee, Eungyoung; Feigley, Charles E; Khan, Jamil A; Hussey, James R

    2006-07-01

    Estimating exposure to contaminants emitted into workroom air is essential for worker protection. Although contaminant concentrations are often not spatially uniform within workrooms, many methods for estimating exposure do not adequately account for this variability. Here the impact of temperature differences within a room on spatial contaminant distribution was studied. Tracer gas (99.5% propylene) concentrations were monitored automatically at 144 sampling points with a photoionization detector. One wall was chosen to represent a building's external wall and was heated or cooled to simulate summer or winter conditions. Experiments were preformed at two flow rates (5.5 and 3.3 m(3) min(-1)) and six thermal conditions (isothermal, three summer conditions and two winter conditions). For 5.5 m(3) min(-1) and all thermal conditions, the coefficient of variation (CV) ranged from 0.34 to 0.45 and the normalized average concentrations were similar. For 3.3 m(3) min(-1), winter conditions produced greater spatial variability of concentration (CV = 0.72 and 1.10) than isothermal or summer conditions (CV range = 0.29-0.34). Tests simulating winter conditions suggest that the resulting stable temperature structure inhibited the dilution of the tracer and enhanced its segregation in the lower portion of the room, especially for the lower flow rate (3.3 m(3) min(-1)). Therefore, not explicitly addressing thermal effect in exposure modeling may impact the estimated accuracy and precision when used for rooms that are non-isothermal and not well mixed. These findings also have implications for air monitoring. Dispersion patterns for different thermal conditions were found to be substantially different, even when the mean concentrations were nearly the same. Thus, monitoring data from a single season should not be taken as representative of the entire year, when summer and winter conditions create temperature gradients in a room.

  14. Loading and unloading of freeze-dryers: airborne contamination risks for aseptically manufactured sterile drug products.

    PubMed

    Ljungqvist, Bengt; Reinmüller, Berit

    2007-01-01

    In pharmaceutical manufacturing, freeze-drying processes can be adversely affected by temperature differences relative to the surrounding air. Loading and unloading of freeze-dryers are performed either without or with temperature differences between the cleanroom and the chamber of the freeze-dryer. This operation can cause a flow of room air through the opening, creating a contamination risk, especially when manual handling of material is performed in this area. To minimize this risk, a high-efficiency particulate air (HEPA) filter unit should be installed above the opening to provide clean air and protect the opening. Here the theoretical relationships are discussed and design criteria are presented.

  15. Loading and unloading of freeze-dryers: airborne contamination risks for aseptically manufactured sterile drug products.

    PubMed

    Ljungqvist, Bengt; Reinmüller, Berit

    2007-01-01

    In pharmaceutical manufacturing, freeze-drying processes can be adversely affected by temperature differences relative to the surrounding air. Loading and unloading of freeze-dryers are performed either without or with temperature differences between the cleanroom and the chamber of the freeze-dryer. This operation can cause a flow of room air through the opening, creating a contamination risk, especially when manual handling of material is performed in this area. To minimize this risk, a high-efficiency particulate air (HEPA) filter unit should be installed above the opening to provide clean air and protect the opening. Here the theoretical relationships are discussed and design criteria are presented. PMID:17390703

  16. Control and reduction of post-metal etch corrosion effects due to airborne molecular contamination

    NASA Astrophysics Data System (ADS)

    Morilla, Carmen; Prieto, Pilar; Barbado, Francisco

    2001-04-01

    Ionic contamination in microelectronic circuitry can have a detrimental effect on device reliability and yield. Post- aluminum etch corrosion has been considered a critical issue in dry plasma etching of aluminum. In this work, we review the actions taken to reduce the amount of defects due to Cl- induced corrosion in the metal lines at our manufacturing line in Lucent Technologies Madrid. Two approaches were followed in a parallel way: on one side manufacturing procedures were modified to reduce at the minimum the exposure of the unprotected metal lines to the clean room environment thus it is avoided any metal corrosion caused by a possible environmental contamination. The second working line was to improve the resistance to corrosion of the post-etched metal. With this aim, our efforts were focused on the passivation step just after the metal etch and prior the photoresist strip. The influence of several parameter settings of the passivation plasma on the resistance of the etched metal to corrosion has been studied. Accelerated corrosion tests were used to monitor the intrinsic metallization susceptibility of corrosion and chlorine and fluorine residuals content in the wafer were measured using ion-chromatography. It was found that a modification in the pressure, plasma power or duration of the passivation step could have a beneficial impact on the amount of chlorine residues left on the metal lines after etch and consequently an enhancement of their resistance to corrosion.

  17. Pre-sampling contamination of filters used in measurements of airborne (1 → 3)-β-D-glucan based on glucan-specific Limulus amebocyte lysate assay.

    PubMed

    Shogren, Elizabeth S; Park, Ju-Hyeong

    2011-04-01

    Air sampling for (1 → 3)-β-D-glucan may be a good method for assessing inhalation exposure to airborne fungi. Pre-sampling contamination of filter media used for sampling (1 → 3)-β-D-glucan may lead to substantial exposure measurement errors. Using the Limulus amebocyte lysate assay, we tested for pre-sampling levels of (1 → 3)-β-D-glucan on three types of filters-mixed cellulose ester (MCE)[1 brand], glass fiber (GF)[1 brand], and polycarbonate (PC)[5 brands]. Levels of (1 → 3)-β-D-glucan on MCE filters exceeded 4586.1 pg per filter. Levels on GF filters averaged 135.3 (± 28.9) pg per filter (range = 94.8-160.4 pg per filter) and levels on PC filters averaged 152.4 (± 236.1) pg per filter (range = non-detectable-1760.7 pg per filter). Efforts to clean MCE and GF filters were unfeasible or unsuccessful. Sonicating PC filters for two hours in ethanol, followed by a wash in pyrogen-free water, effectively eliminated measured levels of (1 → 3)-β-D-glucan on four brands of PC filters, as compared to untreated PC filters. This pretreatment process did not appear to physically damage the PC filters. Air sampling results highlighted the potentially problematic contamination of untreated PC filters. Ensuring that sampling media are free of (1 → 3)-β-D-glucan before sampling is crucial to accurately measure levels of (1 → 3)-β-D-glucan exposure, especially in environments where levels of (1 → 3)-β-D-glucan are low.

  18. Advances in National Capabilities for Consequence Assessment Modeling of Airborne Hazards

    SciTech Connect

    Nasstrom, J; Sugiyama, G; Foster, K; Larsen, S; Kosovic, B; Eme, B; Walker, H; Goldstein, P; Lundquist, J; Pobanz, B; Fulton, J

    2007-11-26

    This paper describes ongoing advancement of airborne hazard modeling capabilities in support of multiple agencies through the National Atmospheric Release Advisory Center (NARAC) and the Interagency Atmospheric Modeling and Atmospheric Assessment Center (IMAAC). A suite of software tools developed by Lawrence Livermore National Laboratory (LLNL) and collaborating organizations includes simple stand-alone, local-scale plume modeling tools for end user's computers, Web- and Internet-based software to access advanced 3-D flow and atmospheric dispersion modeling tools and expert analysis from the national center at LLNL, and state-of-the-science high-resolution urban models and event reconstruction capabilities.

  19. Rapid assessment of water pollution by airborne measurement of chlorophyll content.

    NASA Technical Reports Server (NTRS)

    Arvesen, J. C.; Weaver, E. C.; Millard, J. P.

    1971-01-01

    Present techniques of airborne chlorophyll measurement are discussed as an approach to water pollution assessment. The differential radiometer, the chlorophyll correlation radiometer, and an infrared radiometer for water temperature measurements are described as the key components of the equipment. Also covered are flight missions carried out to evaluate the capability of the chlorophyll correlation radiometer in measuring the chlorophyll content in water bodies with widely different levels of nutrients, such as fresh-water lakes of high and low eutrophic levels, marine waters of high and low productivity, and an estuary with a high sediment content. The feasibility and usefulness of these techniques are indicated.

  20. The hydrological assessment of aerosol effects by the idealized airborne cloud seeding experiment

    NASA Astrophysics Data System (ADS)

    Lee, K.; Lee, B.; Chae, S.; Lee, C.; Choi, Y.

    2012-12-01

    The main source of aerosols over East Asia including the Korean Peninsula is the anthropogenic emission of atmospheric pollutants transported from Chinese industrial areas. For this reason, the researches of aerosol effects are very active in East Asian countries. In case of South Korea, aircraft measurement campaigns and airborne cloud seeding experiments for the meteorological and environmental research have been conducted over the local area of Korean Peninsula since the year of 2010. This project is related with the weather modification research to build up strategies for the regulation or enhancement of precipitation and snowpack for a severe drought in South Korea during a winter season. For this study, the aerosol effect on precipitation by the airborne cloud seeding was simulated using WRF-CHEM model with RADM2/MADE,SORGAM modules. Emission data of 10000μg/(m2s) of unspeciated primary PM2.5 were input at 0.5km altitude for aerosol scenario cases which is the height of airborne cloud seeding experiment. For the control run, the original WRF model with no chemistry/aerosol modules was used. Also, the hydrological model, SWAT (Soil and Water Assessment Tool, USDA/ARS) is incorporated to evaluate this aerosol effects hydrologically for the enhancement of precipitation or snowfall from the results of WRF-CHEM model. The target area is the Andong dam basin (1,584 km2) which is known as one of the important water resources in southern part of South Korea. The date was chosen based on the conditions of airborne cloud seeding experiment (RH>50%, Low Temp.<-3°C, Wind Speeds<5m/s, etc). During the 24 forecasting hour, the aerosol scenario case showed more amounts of accumulated precipitation (about 12%) than those of control run. According to the analysis of SWAT, the enhancement of precipitation in aerosol scenario cases of WRF-CHEM model could influence the increase of about 1.0×106m3 water resources when we assumed the 10% of effective area over the Andong dam

  1. Evaluation of airborne geophysical surveys for large-scale mapping of contaminated mine pools: draft final report

    SciTech Connect

    Hammack, R. W.

    2006-12-28

    Decades of underground coal mining has left about 5,000 square miles of abandoned mine workings that are rapidly filling with water. The water quality of mine pools is often poor; environmental regulatory agencies are concerned because water from mine pools could contaminate diminishing surface and groundwater supplies. Mine pools are also a threat to the safety of current mining operations. Conversely, mine pools are a large, untapped water resource that, with treatment, could be used for a variety of industrial purposes. Others have proposed using mine pools in conjunction with heat pumps as a source of heating and cooling for large industrial facilities. The management or use of mine pool water requires accurate maps of mine pools. West Virginia University has predicted the likely location and volume of mine pools in the Pittsburgh Coalbed using existing mine maps, structure contour maps, and measured mine pool elevations. Unfortunately, mine maps only reflect conditions at the time of mining, are not available for all mines, and do not always denote the maximum extent of mining. Since 1999, the National Energy Technology Laboratory (NETL) has been evaluating helicopter-borne, electromagnetic sensing technologies for the detection and mapping of mine pools. Frequency domain electromagnetic sensors are able to detect shallow mine pools (depth < 50 m) if there is sufficient contrast between the conductance of the mine pool and the conductance of the overburden. The mine pools (conductors) most confidently detected by this technology are overlain by thick, resistive sandstone layers. In 2003, a helicopter time domain electromagnetic sensor was applied to mined areas in southwestern Virginia in an attempt to increase the depth of mine pool detection. This study failed because the mine pool targets were thin and not very conductive. Also, large areas of the surveys were degraded or made unusable by excessive amounts of cultural electromagnetic noise that obscured the

  2. Toxicity assessment for RMA target contaminants. Volume 1. Endangerment assessment RMA, task 35. Final draft report

    SciTech Connect

    1987-06-01

    This report is detailed discussion of the evaluations performed to develop the toxicity assessment for RMA contaminants in soil. The objectives of the toxicity assessment are to determine the nature and extent of health and environmental hazards associated with exposure to contaminants present at the site and identify a quantitative index of toxicity for each target contaminant, referred to in this assessment as DT. The toxicity assessment for the RMA target contaminants has been performed consistent with published EPA guidelines and addresses only human health hazards associated with contaminants in soil. Each toxicity profile is composed of seven sections: 1. summary; 2. chemical and physical properties; and 3. transport and rate.

  3. Orbiter/payload contamination control assessment support

    NASA Technical Reports Server (NTRS)

    Rantanen, R. O.; Strange, D. A.; Hetrick, M. A.

    1978-01-01

    The development and integration of 16 payload bay liner filters into the existing shuttle/payload contamination evaluation (SPACE) computer program is discussed as well as an initial mission profile model. As part of the mission profile model, a thermal conversion program, a temperature cycling routine, a flexible plot routine and a mission simulation of orbital flight test 3 are presented.

  4. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

    EPA Science Inventory

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accord...

  5. Assessment of community contamination: a critical approach.

    PubMed

    Clark, Lauren; Barton, Judith A; Brown, Nancy J

    2002-01-01

    The purpose of this paper is to review data from two Superfund sites and describe the latitude of interpretation of "environmental risk" by residents living in the area, governmental agencies, and the media. The first community was located within a 5-mi perimeter of the Rocky Flats Environmental Technology Site (RFETS) outside Denver, Colorado. The second community was located on the south side of Tucson, Arizona, adjacent to the Tucson International Airport area (TIAA) Superfund site. Critical theory was the perspective used in this analysis and proposal of public health actions to attain social justice. Differences between the two populations' experiences with risk and contamination coincided with divergent levels of trust in government. RFETS residents demanded monitoring, whereas the minority residents at TIAA were ambivalent about their trust in government cleanup activities. Unraveling the purpose of "facts" and the social force of "truth" can direct nurses to address environmental justice issues. By policing governmental and business activities in halting or cleaning up environmental contamination, nurses may become mouthpieces for the concerns underlying the fragile surface of "virtual trust" in contaminated communities. Cutting through competing rhetoric to police environmental safety, the core function of assurance becomes what nurses do, not what they say. PMID:12182695

  6. Assessment of community contamination: a critical approach.

    PubMed

    Clark, Lauren; Barton, Judith A; Brown, Nancy J

    2002-01-01

    The purpose of this paper is to review data from two Superfund sites and describe the latitude of interpretation of "environmental risk" by residents living in the area, governmental agencies, and the media. The first community was located within a 5-mi perimeter of the Rocky Flats Environmental Technology Site (RFETS) outside Denver, Colorado. The second community was located on the south side of Tucson, Arizona, adjacent to the Tucson International Airport area (TIAA) Superfund site. Critical theory was the perspective used in this analysis and proposal of public health actions to attain social justice. Differences between the two populations' experiences with risk and contamination coincided with divergent levels of trust in government. RFETS residents demanded monitoring, whereas the minority residents at TIAA were ambivalent about their trust in government cleanup activities. Unraveling the purpose of "facts" and the social force of "truth" can direct nurses to address environmental justice issues. By policing governmental and business activities in halting or cleaning up environmental contamination, nurses may become mouthpieces for the concerns underlying the fragile surface of "virtual trust" in contaminated communities. Cutting through competing rhetoric to police environmental safety, the core function of assurance becomes what nurses do, not what they say.

  7. Airborne lidar for ocean-atmosphere studies and assessment of future satellite mission concepts

    NASA Astrophysics Data System (ADS)

    Hostetler, C. A.; Hair, J. W.; Hu, Y.; Behrenfeld, M. J.; Cetinic, I.; Butler, C. F.; Powell, K. A.; Ferrare, R. A.; Burton, S. P.; Cairns, B.; Chowdhary, J.; Hare, R. J.; Harper, D. B.; Cook, A. L.; Berkoff, T.; Mack, T. L.; Notari, A.; Woodell, G. A.

    2014-12-01

    Global estimates of phytoplankton biomass (Cphyto) and particulate organic carbon (POC) have traditionally been made using passive ocean color measurements. Recently, data from the CALIOP sensor on the CALIPSO satellite have provided the first measurements of these two key carbon cycle stocks from a space-based lidar. Although CALIOP was not designed for subsurface ocean retrievals, global distributions of Cphyto and POC retrieved with CALIOP compare well with independent assessments using MODIS passive ocean color data. This success suggests a potentially important future role for space lidar measurements in global ocean plankton research, particularly for a lidar system optimized for water column profiling. To this end, the NASA Langley airborne High Spectral Resolution Lidar (HSRL) was recently modified for ocean research to provide independent vertically-resolved retrievals of the diffuse attenuation coefficient (Kd) and particulate backscatter coefficient (bbp). The advanced HSRL has been deployed on three ocean-focused airborne field missions: a mission based in the Azores in October 2012, a CALIPSO validation mission based in Bermuda in June 2014, and the Ship-Aircraft Bio-Optical Research (SABOR) experiment based in Bermuda, New Hampshire, and Virginia in July-August of 2014. On the Azores and SABOR missions, the HSRL instrument acquired data coincident with ship-based optical measurements, and data were acquired along CALIOP tracks on all three missions. Results from the airborne HSRL and CALIOP studies will be described, along with a discussion of potential future aircraft campaigns, the scalability of the HSRL technique to space, and the value of simultaneously measuring plankton abundance, marine aerosol loading and optical properties, and cloud microphysical properties and albedo.

  8. Evaluation of the area factor used in the RESRAD code for the estimation of airborne contaminant concentrations of finite area sources

    SciTech Connect

    Chang, Y.S.; Yu, C.; Wang, S.K.

    1998-07-01

    The area factor is used in the RESRAD code to estimate the airborne contaminant concentrations for a finite area of contaminated soils. The area factor model used in RESRAD version 5.70 and earlier (referred to as the old area factor) was a simple, but conservative, mixing model that tended to overestimate the airborne concentrations of radionuclide contaminants. An improved and more realistic model for the area factor (referred to here as the new area factor) is described in this report. The new area factor model is designed to reflect site-specific soil characteristics and meteorological conditions. The site-specific parameters considered include the size of the source area, average particle diameter, and average wind speed. Other site-specific parameters (particle density, atmospheric stability, raindrop diameter, and annual precipitation rate) were assumed to be constant. The model uses the Gaussian plume model combined with contaminant removal processes, such as dry and wet deposition of particulates. Area factors estimated with the new model are compared with old area factors that were based on the simple mixing model. In addition, sensitivity analyses are conducted for parameters assumed to be constant. The new area factor model has been incorporated into RESRAD version 5.75 and later.

  9. Sick building syndrome: Acute illness among office workers--the role of building ventilation, airborne contaminants and work stress

    SciTech Connect

    Letz, G.A. )

    1990-05-01

    Outbreaks of acute illness among office workers have been reported with increasing frequency during the past 10-15 years. In the majority of cases, hazardous levels of airborne contaminants have not been found. Generally, health complaints have involved mucous membrane and respiratory tract irritation and nonspecific symptoms such as headache and fatigue. Except for rare examples of hypersensitivity pneumonitis related to microbiologic antigens, there have been no reports of serious morbidity or permanent sequelae. However, the anxiety, lost work time, decreased productivity and resources spent in investigating complaints has been substantial. NIOSH has reported on 446 Health Hazards Evaluations that were done in response to indoor air complaints. This data base is the source of most of the published accounts of building-related illness. Their results are summarized here with a discussion of common pollutants (tobacco smoke, formaldehyde, other organic volatiles), and the limitations of the available industrial hygiene and epidemiologic data. There has been one large scale epidemiologic survey of symptoms among office workers. The results associate risk of symptoms to building design and characteristics of the heating/air-conditioning systems, consistent with the NIOSH experience. Building construction since the 1970s has utilized energy conservation measures such as improved insulation, reduced air exchange, and construction without opening windows. These buildings are considered airtight and are commonly involved in episodes of building-associated illness in which no specific etiologic agent can be identified. After increasing the percentage of air exchange or correcting specific deficiencies found in the heating/air-conditioning systems, the health complaints often resolve, hence, the term tight building syndrome or sick building syndrome.

  10. Antioxidant therapy attenuates oxidative stress in the blood of subjects exposed to occupational airborne contamination from coal mining extraction and incineration of hospital residues.

    PubMed

    Wilhelm Filho, D; Avila, S; Possamai, F P; Parisotto, E B; Moratelli, A M; Garlet, T R; Inácio, D B; Torres, M A; Colepicolo, P; Dal-Pizzol, F

    2010-10-01

    Coal mining and incineration of solid residues of health services (SRHS) generate several contaminants that are delivered into the environment, such as heavy metals and dioxins. These xenobiotics can lead to oxidative stress overgeneration in organisms and cause different kinds of pathologies, including cancer. In the present study the concentrations of heavy metals such as lead, copper, iron, manganese and zinc in the urine, as well as several enzymatic and non-enzymatic biomarkers of oxidative stress in the blood (contents of lipoperoxidation = TBARS, protein carbonyls = PC, protein thiols = PT, α-tocopherol = AT, reduced glutathione = GSH, and the activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in the blood of six different groups (n = 20 each) of subjects exposed to airborne contamination related to coal mining as well as incineration of solid residues of health services (SRHS) after vitamin E (800 mg/day) and vitamin C (500 mg/day) supplementation during 6 months, which were compared to the situation before the antioxidant intervention (Ávila et al., Ecotoxicology 18:1150-1157, 2009; Possamai et al., Ecotoxicology 18:1158-1164, 2009). Except for the decreased manganese contents, heavy metal concentrations were elevated in all groups exposed to both sources of airborne contamination when compared to controls. TBARS and PC concentrations, which were elevated before the antioxidant intervention decreased after the antioxidant supplementation. Similarly, the contents of PC, AT and GSH, which were decreased before the antioxidant intervention, reached values near those found in controls, GPx activity was reestablished in underground miners, and SOD, CAT and GST activities were reestablished in all groups. The results showed that the oxidative stress condition detected previously to the antioxidant supplementation in both directly and indirectly subjects

  11. Probabilistic assessment of ground-water contamination. 1: Geostatistical framework

    SciTech Connect

    Rautman, C.A.; Istok, J.D.

    1996-09-01

    Characterizing the extent and severity of ground-water contamination at waste sites is expensive and time-consuming. A probabilistic approach, based on the acceptance of uncertainty and a finite probability of making classification errors (contaminated relative to a regulatory threshold vs. uncontaminated), is presented as an alternative to traditional site characterization methodology. The approach utilizes geostatistical techniques to identify and model the spatial continuity of contamination at a site (variography) and to develop alternate plausible simulations of contamination fields (conditional simulation). Probabilistic summaries of many simulations provide tools for (a) estimating the range of plausible contaminant concentrations at unsampled locations, (b) identifying the locations of boundaries between contaminated and uncontaminated portions of the site and the degree of certainty in those locations, and (c) estimating the range of plausible values for total contaminant mass. The first paper in the series presents the geostatistical framework and illustrates the approach using synthetic data for a hypothetical site. The second paper presents an application of the proposed methodology to the probabilistic assessment of ground-water contamination at a site involving ground-water contamination by nitrate and herbicide in a shallow, unconfined alluvial aquifer in an agricultural area in eastern Oregon.

  12. Assessment of surface contamination with contact mechanics

    SciTech Connect

    EMERSON,JOHN A.; MILLER,GREGORY V.; SORENSEN,CHRISTOPHER R.; PEARSON,RAYMOND A.

    2000-02-21

    The authors are particularly interested in the work of adhesion measurements as a means to facilitate the understanding of the adhesive failure mechanisms for systems containing encapsulated and bonded components. Of the several issues under investigation, one is the effect of organic contamination on the adhesive strength for several types of polymer/metal interface combinations. The specific question that the authors are trying to address is at what level of contamination does adhesive strength decrease. The use of contact mechanics, the JKR method, is a good approach for studying this question. Another approach being studied is the use of interracial fracture mechanics. The model contaminant is hexadecane--non-polar, medium molecular weight hydrocarbon fluid. They choose hexadecane because it replicates typical machining fluids, is nonreactive with Al surfaces, and should not dissolve readily into the adhesive systems of interest. The application of a uniform, controllable and reproducible hexadecane layer on Al surfaces has proven to be difficult. A primary concern is whether studies of model systems can be extended to systems of technological interest. The JKR theory is a continuum mechanics model of contact between two solid spheres that was developed by Johnson, Kendall and Roberts. The JKR theory is an extension of Hertzian contact theory and attributes the additional increase in the contact area between a soft elastomeric hemisphere to adhesive forces between the two surfaces. The JKR theory allows a direct estimate of the surface free energy of interface as well as the work of adhesion (Wa) between solids. Early studies performed in this laboratory involved the determination of Wa between silicone (PDMS) and Al surfaces in order to establish the potential adhesive failure mechanisms. However, the JKR studies using commercial based PDMS [poly(dimethylsiloxane)] was fraught with difficulty that were attributed to the additives used in commercial PDMS

  13. Nephropathy in cadmium workers: assessment of risk from airborne occupational exposure to cadmium.

    PubMed Central

    Thun, M J; Osorio, A M; Schober, S; Hannon, W H; Lewis, B; Halperin, W

    1989-01-01

    To assess the quantitative relation between exposure to airborne cadmium and various markers of renal tubular and glomerular function, 45 male workers employed at a plant that recovers cadmium from industrial waste and 32 male hospital workers of similar age and geographical location were examined. Cumulative external exposure to airborne cadmium (dose) was estimated from historical air sampling data, adjusted for respirator use. Increasing cadmium dose was associated with multiple renal tubular functional abnormalities, including reduced reabsorption of beta-2-microglobulin (beta-2), retinol binding protein (RBP), calcium, and phosphate. Serum creatinine concentration also increased with cadmium dose, suggesting impaired glomerular function. Mean systolic and diastolic blood pressures were higher in the cadmium workers than in the unexposed (134 v 120 mm Hg and 80 v 73 mm Hg respectively), but only systolic blood pressure was significantly associated with cadmium dose in multivariate analyses. Cadmium dose remained the most important predictor of serum creatinine concentration after controlling for age, blood pressure, body size, and other extraneous factors. Logistic regression to model the probability (prevalence) of various renal abnormalities with increasing dose of cadmium was used. The probability of multiple tubular abnormalities and raised serum creatinine concentration increased sharply at cumulative cadmium exposures exceeding 300 mg/m3 days, corresponding to working for 4.3 years at the current permissible United States exposure limit for cadmium dust. PMID:2818957

  14. Assessment of airborne environmental bacteria and related factors in 25 underground railway stations in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Hwang, Sung Ho; Yoon, Chung Sik; Ryu, Kyong Nam; Paik, Samuel Y.; Cho, Jun Ho

    2010-05-01

    This study assessed bacterial concentrations in indoor air at 25 underground railway stations in Seoul, Korea, and investigated various related factors including the presence of platform screen doors (PSD), depth of the station, year of construction, temperature, relative humidity, and number of passengers. A total of 72 aerosol samples were collected from all the stations. Concentrations of total airborne bacteria (TAB) ranged from not detected (ND) to 4997 CFU m -3, with an overall geometric mean (GM) of 191 CFU m -3. Airborne bacteria were detected at 23 stations (92%) and Gram-negative bacteria (GNB) were detected at two stations (8%). TAB concentrations of four stations (16%) exceeded 800 CFU m -3, the Korea indoor bio-aerosol guideline. The results of the study showed that TAB concentrations at the stations without PSD showed higher TAB concentrations than those with PSD, though not at statistically significant levels. TAB concentrations of deeper stations revealed significantly higher levels than those of shallower stations. Based on this study, it is recommended that mitigation measures be applied to improve the indoor air quality (IAQ) of underground railway stations in Seoul, with focused attention on deeper stations.

  15. Comprehensive methodology for ecological risk assessment of contaminated soils

    SciTech Connect

    Kuperman, R.G.

    1994-12-31

    Development of a comprehensive methodology for ecological risk assessment and monitoring of contaminated soils is essential to assess the impacts of environmental contaminants on soil community and biologically-mediated processes in soil. The proposed four-step plan involves (1) a thorough survey of the soil community to establish biodiversity and a base-line community structure, (2) toxicity trials on indicator species and whole soil invertebrate communities, (3) laboratory and field tests on indicator processes and (4) the use of statistical and simulation models to ascertain changes in the soil ecosystems. This methodology was used in portions of the US Army`s Aberdeen Proving Ground, Maryland as part of an ecological risk assessment. Previous soil analyses showed extensive surface soil contamination with metals, nitrate and PCBs. Preliminary results from field surveys of soil invertebrate communities showed significant reductions in total abundance of animals, reductions in the abundance of several taxonomic and functional groups of soil invertebrates, and changes in the activity of epigeic arthropods in contaminated areas when compared with the local ``background`` area. Laboratory tests also demonstrated that microbial activity and success of egg hatching of ground beetle Harpalus pensylvanicus were reduced in contaminated soils. These results suggest that impacts to soil ecosystems should be explicitly considered in ecological risk assessment. The proposed comprehensive methodology appears to offer an efficient and potentially cost saving tool for remedial investigations of contaminated sites.

  16. Assessing soil and groundwater contamination in a metropolitan redevelopment project.

    PubMed

    Yun, Junki; Lee, Ju Young; Khim, Jeehyeong; Ji, Won Hyun

    2013-08-01

    The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α). PMID:23307052

  17. Assessing soil and groundwater contamination in a metropolitan redevelopment project.

    PubMed

    Yun, Junki; Lee, Ju Young; Khim, Jeehyeong; Ji, Won Hyun

    2013-08-01

    The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α).

  18. Directed air flow to reduce airborne particulate and bacterial contamination in the surgical field during total hip arthroplasty.

    PubMed

    Stocks, Gregory W; O'Connor, Daniel P; Self, Sean D; Marcek, Geoff A; Thompson, Brandon L

    2011-08-01

    This study evaluated the use of a system that delivers a small field of local, directed air from a high-efficiency particulate air (HEPA) filter to reduce airborne particulate and airborne bacteria in the surgical field during total hip arthroplasty. Thirty-six patients were randomized into 3 groups: with directed air flow, with the directed air flow system present but turned off, and control. Airborne particulate and bacteria were collected from within 5 cm of the surgical wound. All particulate and bacterial counts at the surgical site were significantly lower in the directed air flow group (P < .001). The directed air flow system was effective in reducing airborne particulate and colony-forming units in the surgical field during total hip arthroplasty. PMID:20851565

  19. Passive sampling methods for contaminated sediments: Risk assessment and management

    PubMed Central

    Greenberg, Marc S; Chapman, Peter M; Allan, Ian J; Anderson, Kim A; Apitz, Sabine E; Beegan, Chris; Bridges, Todd S; Brown, Steve S; Cargill, John G; McCulloch, Megan C; Menzie, Charles A; Shine, James P; Parkerton, Thomas F

    2014-01-01

    This paper details how activity-based passive sampling methods (PSMs), which provide information on bioavailability in terms of freely dissolved contaminant concentrations (Cfree), can be used to better inform risk management decision making at multiple points in the process of assessing and managing contaminated sediment sites. PSMs can increase certainty in site investigation and management, because Cfree is a better predictor of bioavailability than total bulk sediment concentration (Ctotal) for 4 key endpoints included in conceptual site models (benthic organism toxicity, bioaccumulation, sediment flux, and water column exposures). The use of passive sampling devices (PSDs) presents challenges with respect to representative sampling for estimating average concentrations and other metrics relevant for exposure and risk assessment. These challenges can be addressed by designing studies that account for sources of variation associated with PSMs and considering appropriate spatial scales to meet study objectives. Possible applications of PSMs include: quantifying spatial and temporal trends in bioavailable contaminants, identifying and evaluating contaminant source contributions, calibrating site-specific models, and, improving weight-of-evidence based decision frameworks. PSM data can be used to assist in delineating sediment management zones based on likelihood of exposure effects, monitor remedy effectiveness, and, evaluate risk reduction after sediment treatment, disposal, or beneficial reuse after management actions. Examples are provided illustrating why PSMs and freely dissolved contaminant concentrations (Cfree) should be incorporated into contaminated sediment investigations and study designs to better focus on and understand contaminant bioavailability, more accurately estimate exposure to sediment-associated contaminants, and better inform risk management decisions. Research and communication needs for encouraging broader use are discussed. Integr

  20. On-site application of air cleaner emitting plasma ion to reduce airborne contaminants in pig building

    NASA Astrophysics Data System (ADS)

    Cho, Man Su; Ko, Han Jong; Kim, Daekeun; Kim, Ki Youn

    2012-12-01

    The objective of this field study is to evaluate temporal reduction efficiency of air cleaner emitting plasma ion on airborne pollutants emitted from pig building. The operation principle of air cleaner based on plasma ion is that hydrogen atoms and oxygen ions combine to form hydroperoxyl radicals (HOO-), which surround and attach to surface of airborne microorganisms and eliminate them by breaking the hydrogen bond in their protein structure. In gaseous pollutants, it was found that there is no reduction effect of the air cleaner on ammonia and hydrogen sulfide (p > 0.05). In particulate pollutants, the air cleaner showed mean 79%(±6.1) and 78%(±3.0) of reduction efficiency for PM2.5. and PM1, respectively, compared to the control without air cleaner (p < 0.05). However, there is no significant difference in TSP and PM10 between the treatment with air cleaner and the control without air cleaner (p > 0.05). In biological pollutants, the mean reduction efficiencies for airborne bacteria and fungi by application of air cleaner were 22%(±6.6) and 25%(±8.7), respectively (p < 0.05). Based on the results obtained from this study, it was concluded that the air cleaner had a positive reduction effect on PM2.5, PM1, airborne bacteria and airborne fungi among airborne pollutants distributed in pig building while it did not lead to significant reduction of ammonia and hydrogen sulfide.

  1. Use of high-performance liquid chromatography to assess airborne mycotoxins. Aflatoxins and ochratoxin A.

    PubMed

    Tarín, A; Rosell, M G; Guardino, X

    2004-08-27

    An HPLC analytical method combining methanol-deionised water (80:20, v/v) extraction, methanol-acetonitrile (50:50, v/v) extraction and fluorescence detection was implanted to analyse ochratoxin A and aflatoxins B1, B2, G1 and G2 of air samples collected during the usual production process in a number of workplaces of a coffee factory to assess the occupational exposure of the engaged workers. The average levels of airborne ochratoxin A and aflatoxins were less than 1.2 and 0.4 ng/m3, respectively, using 50 L air samples. When 150 L air samples were used, levels lower than 0.04 ng/m3 ochratoxin A and 0.013 ng/m3 for aflatoxins B1, B2, G1 and G2, could be detected.

  2. Discriminating semiarid vegetation using airborne imaging spectrometer data - A preliminary assessment

    NASA Technical Reports Server (NTRS)

    Thomas, Randall W.; Ustin, Susan L.

    1987-01-01

    A preliminary assessment was made of Airborne Imaging Spectrometer (AIS) data for discriminating and characterizing vegetation in a semiarid environment. May and October AIS data sets were acquired over a large alluvial fan in eastern California, on which were found Great Basin desert shrub communities. Maximum likelihood classification of a principal components representation of the May AIS data enabled discrimination of subtle spatial detail in images relating to vegetation and soil characteristics. The spatial patterns in the May AIS classification were, however, too detailed for complete interpretation with existing ground data. A similar analysis of the October AIS data yielded poor results. Comparison of AIS results with a similar analysis of May Landsat Thematic Mapper data showed that the May AIS data contained approximately three to four times as much spectrally coherent information. When only two shortwave infrared TM bands were used, results were similar to those from AIS data acquired in October.

  3. Effect of proximity to a cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens and evaluation of the potential for airborne transmission.

    PubMed

    Berry, Elaine D; Wells, James E; Bono, James L; Woodbury, Bryan L; Kalchayanand, Norasak; Norman, Keri N; Suslow, Trevor V; López-Velasco, Gabriela; Millner, Patricia D

    2015-02-01

    The impact of proximity to a beef cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens was examined. In each of 2 years, leafy greens were planted in nine plots located 60, 120, and 180 m from a cattle feedlot (3 plots at each distance). Leafy greens (270) and feedlot manure samples (100) were collected six different times from June to September in each year. Both E. coli O157:H7 and total E. coli bacteria were recovered from leafy greens at all plot distances. E. coli O157:H7 was recovered from 3.5% of leafy green samples per plot at 60 m, which was higher (P < 0.05) than the 1.8% of positive samples per plot at 180 m, indicating a decrease in contamination as distance from the feedlot was increased. Although E. coli O157:H7 was not recovered from air samples at any distance, total E. coli was recovered from air samples at the feedlot edge and all plot distances, indicating that airborne transport of the pathogen can occur. Results suggest that risk for airborne transport of E. coli O157:H7 from cattle production is increased when cattle pen surfaces are very dry and when this situation is combined with cattle management or cattle behaviors that generate airborne dust. Current leafy green field distance guidelines of 120 m (400 feet) may not be adequate to limit the transmission of E. coli O157:H7 to produce crops planted near concentrated animal feeding operations. Additional research is needed to determine safe set-back distances between cattle feedlots and crop production that will reduce fresh produce contamination.

  4. Effect of Proximity to a Cattle Feedlot on Escherichia coli O157:H7 Contamination of Leafy Greens and Evaluation of the Potential for Airborne Transmission

    PubMed Central

    Wells, James E.; Bono, James L.; Woodbury, Bryan L.; Kalchayanand, Norasak; Norman, Keri N.; Suslow, Trevor V.; López-Velasco, Gabriela; Millner, Patricia D.

    2014-01-01

    The impact of proximity to a beef cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens was examined. In each of 2 years, leafy greens were planted in nine plots located 60, 120, and 180 m from a cattle feedlot (3 plots at each distance). Leafy greens (270) and feedlot manure samples (100) were collected six different times from June to September in each year. Both E. coli O157:H7 and total E. coli bacteria were recovered from leafy greens at all plot distances. E. coli O157:H7 was recovered from 3.5% of leafy green samples per plot at 60 m, which was higher (P < 0.05) than the 1.8% of positive samples per plot at 180 m, indicating a decrease in contamination as distance from the feedlot was increased. Although E. coli O157:H7 was not recovered from air samples at any distance, total E. coli was recovered from air samples at the feedlot edge and all plot distances, indicating that airborne transport of the pathogen can occur. Results suggest that risk for airborne transport of E. coli O157:H7 from cattle production is increased when cattle pen surfaces are very dry and when this situation is combined with cattle management or cattle behaviors that generate airborne dust. Current leafy green field distance guidelines of 120 m (400 feet) may not be adequate to limit the transmission of E. coli O157:H7 to produce crops planted near concentrated animal feeding operations. Additional research is needed to determine safe set-back distances between cattle feedlots and crop production that will reduce fresh produce contamination. PMID:25452286

  5. Performance assessment of onboard and scene-based methods for Airborne Prism Experiment spectral characterization.

    PubMed

    D'Odorico, Petra; Guanter, Luis; Schaepman, Michael E; Schläpfer, Daniel

    2011-08-20

    Accurate spectral calibration of airborne and spaceborne imaging spectrometers is essential for proper preprocessing and scientific exploitation of high spectral resolution measurements of the land and atmosphere. A systematic performance assessment of onboard and scene-based methods for in-flight monitoring of instrument spectral calibration is presented for the first time in this paper. Onboard and ground imaging data were collected at several flight altitudes using the Airborne Prism Experiment (APEX) imaging spectrometer. APEX is equipped with an in-flight characterization (IFC) facility allowing the evaluation of radiometric, spectral, and geometric system properties, both in-flight and on-ground for the full field of view. Atmospheric and onboard filter spectral features present in at-sensor radiances are compared with the same features in reference transmittances convolved to varying instrument spectral configurations. A spectrum-matching algorithm, taking advantage of the high sensitivity of measurements around sharp spectral features toward spectrometer spectral performance, is used to retrieve channel center wavelength and bandwidth parameters. Results showed good agreement between spectral parameters estimated using onboard IFC and ground imaging data. The average difference between estimates obtained using the O(2) and H(2)O features and those obtained using the corresponding filter features amounted to about 0.3 nm (0.05 of a spectral pixel). A deviation from the nominal laboratory instrument spectral calibration and an altitude-dependent performance was additionally identified. The relatively good agreement between estimates obtained by the two approaches in similar spectral windows suggests they can be used in a complementary fashion: while the method relying on atmospheric features can be applied without the need for dedicated calibration acquisitions, the IFC allows assessment at user-selectable wavelength positions by custom filters as well as for

  6. Developing an integration tool for soil contamination assessment

    NASA Astrophysics Data System (ADS)

    Anaya-Romero, Maria; Zingg, Felix; Pérez-Álvarez, José Miguel; Madejón, Paula; Kotb Abd-Elmabod, Sameh

    2015-04-01

    In the last decades, huge soil areas have been negatively influenced or altered in multiples forms. Soils and, consequently, underground water, have been contaminated by accumulation of contaminants from agricultural activities (fertilizers and pesticides) industrial activities (harmful material dumping, sludge, flying ashes) and urban activities (hydrocarbon, metals from vehicle traffic, urban waste dumping). In the framework of the RECARE project, local partners across Europe are focusing on a wide range of soil threats, as soil contamination, and aiming to develop effective prevention, remediation and restoration measures by designing and applying targeted land management strategies (van Lynden et al., 2013). In this context, the Guadiamar Green Corridor (Southern Spain) was used as a case study, aiming to obtain soil data and new information in order to assess soil contamination. The main threat in the Guadiamar valley is soil contamination after a mine spill occurred on April 1998. About four hm3 of acid waters and two hm3 of mud, rich in heavy metals, were released into the Agrio and Guadiamar rivers affecting more than 4,600 ha of agricultural and pasture land. Main trace elements contaminating soil and water were As, Cd, Cu, Pb, Tl and Zn. The objective of the present research is to develop informatics tools that integrate soil database, models and interactive platforms for soil contamination assessment. Preliminary results were obtained related to the compilation of harmonized databases including geographical, hydro-meteorological, soil and socio-economic variables based on spatial analysis and stakeholder's consultation. Further research will be modellization and upscaling at the European level, in order to obtain a scientifically-technical predictive tool for the assessment of soil contamination.

  7. Use of In Situ and Airborne Multiangle Data to Assess MODIS- and Landsat-based Estimates of Surface Albedo

    NASA Technical Reports Server (NTRS)

    Roman, Miguel O.; Gatebe, Charles K.; Shuai, Yanmin; Wang, Zhuosen; Gao, Feng; Masek, Jeff; Schaaf, Crystal B.

    2012-01-01

    The quantification of uncertainty of global surface albedo data and products is a critical part of producing complete, physically consistent, and decadal land property data records for studying ecosystem change. A current challenge in validating satellite retrievals of surface albedo is the ability to overcome the spatial scaling errors that can contribute on the order of 20% disagreement between satellite and field-measured values. Here, we present the results from an uncertain ty analysis of MODerate Resolution Imaging Spectroradiometer (MODIS) and Landsat albedo retrievals, based on collocated comparisons with tower and airborne multi-angular measurements collected at the Atmospheric Radiation Measurement Program s (ARM) Cloud and Radiation Testbed (CART) site during the 2007 Cloud and Land Surface Interaction Campaign (CLAS33 IC 07). Using standard error propagation techniques, airborne measurements obtained by NASA s Cloud Absorption Radiometer (CAR) were used to quantify the uncertainties associated with MODIS and Landsat albedos across a broad range of mixed vegetation and structural types. Initial focus was on evaluating inter-sensor consistency through assessments of temporal stability, as well as examining the overall performance of satellite-derived albedos obtained at all diurnal solar zenith angles. In general, the accuracy of the MODIS and Landsat albedos remained under a 10% margin of error in the SW(0.3 - 5.0 m) domain. However, results reveal a high degree of variability in the RMSE (root mean square error) and bias of albedos in both the visible (0.3 - 0.7 m) and near-infrared (0.3 - 5.0 m) broadband channels; where, in some cases, retrieval uncertainties were found to be in excess of 20%. For the period of CLASIC 07, the primary factors that contributed to uncertainties in the satellite-derived albedo values include: (1) the assumption of temporal stability in the retrieval of 500 m MODIS BRDF values over extended periods of cloud-contaminated

  8. SOFTWARE TOOLS FOR ASSESSMENT OF CONTAMINATED SITES

    EPA Science Inventory

    Models have become an integral part of decision-making for many LUST sites if only because they form the basis of RCBA tiered assessments. Models, though, are based on a series of assumptions concerning how chemicals behave in the environment, how water flows through the ground,...

  9. Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling

    NASA Astrophysics Data System (ADS)

    Keaney, Antoinette; McKinley, Jennifer; Ruffell, Alastair; Robinson, Martin; Graham, Conor; Hodgson, Jim; Desissa, Mohammednur

    2013-04-01

    The Kyoto Agreement demands that all signatory countries have an inventory of their carbon stock, plus possible future changes to this store. This is particularly important for Ireland, where some 16% of the surface is covered by peat bog. Estimates of soil carbon stores are a key component of the required annual returns made by the Irish and UK governments to the Intergovernmental Panel on Climate Change. Saturated peat attenuates gamma-radiation from underlying rocks. This effect can be used to estimate the thickness of peat, within certain limits. This project examines this relationship between peat depth and gamma-radiation using airborne geophysical data generated by the Tellus Survey and newly acquired data collected as part of the EU-funded Tellus Border project, together encompassing Northern Ireland and the border area of the Republic of Ireland. Selected peat bog sites are used to ground truth and evaluate the use of airborne geophysical (radiometric and electromagnetic) data and validate modelled estimates of soil carbon, peat volume and depth to bedrock. Data from two test line sites are presented: one in Bundoran, County Donegal and a second line in Sliabh Beagh, County Monaghan. The plane flew over these areas at different times of the year and at a series of different elevations allowing the data to be assessed temporally with different soil/peat saturation levels. On the ground these flight test lines cover varying surface land use zones allowing future extrapolation of data from the sites. This research applies spatial statistical techniques, including uncertainty estimation in geostatistical prediction and simulation, to investigate and model the use of airborne geophysical data to examine the relationship between reduced radioactivity and peat depth. Ground truthing at test line locations and selected peat bog sites involves use of ground penetrating radar, terrestrial LiDAR, peat depth probing, magnetometry, resistivity, handheld gamma

  10. Airborne laser scanning for forest health status assessment and radiative transfer modelling

    NASA Astrophysics Data System (ADS)

    Novotny, Jan; Zemek, Frantisek; Pikl, Miroslav; Janoutova, Ruzena

    2013-04-01

    Structural parameters of forest stands/ecosystems are an important complementary source of information to spectral signatures obtained from airborne imaging spectroscopy when quantitative assessment of forest stands are in the focus, such as estimation of forest biomass, biochemical properties (e.g. chlorophyll /water content), etc. The parameterization of radiative transfer (RT) models used in latter case requires three-dimensional spatial distribution of green foliage and woody biomass. Airborne LiDAR data acquired over forest sites bears these kinds of 3D information. The main objective of the study was to compare the results from several approaches to interpolation of digital elevation model (DEM) and digital surface model (DSM). We worked with airborne LiDAR data with different density (TopEye Mk II 1,064nm instrument, 1-5 points/m2) acquired over the Norway spruce forests situated in the Beskydy Mountains, the Czech Republic. Three different interpolation algorithms with increasing complexity were tested: i/Nearest neighbour approach implemented in the BCAL software package (Idaho Univ.); ii/Averaging and linear interpolation techniques used in the OPALS software (Vienna Univ. of Technology); iii/Active contour technique implemented in the TreeVis software (Univ. of Freiburg). We defined two spatial resolutions for the resulting coupled raster DEMs and DSMs outputs: 0.4 m and 1 m, calculated by each algorithm. The grids correspond to the same spatial resolutions of hyperspectral imagery data for which the DEMs were used in a/geometrical correction and b/building a complex tree models for radiative transfer modelling. We applied two types of analyses when comparing between results from the different interpolations/raster resolution: 1/calculated DEM or DSM between themselves; 2/comparison with field data: DEM with measurements from referential GPS, DSM - field tree alometric measurements, where tree height was calculated as DSM-DEM. The results of the analyses

  11. Allergy arising from exposure to airborne contaminants in an insect rearing facility: Health effects and exposure control

    SciTech Connect

    Wolff, D.

    1994-06-01

    In agricultural crop improvement, yield under various stress conditions and limiting factors is assessed experimentally. Of the stresses on plants which affect yield are those due to insects. Ostrinia nubilalis, the European corn borer (corn borer) is a major pest in sweet and field corn in the U.S. There are many ways to fight crop pests such as the corn borer, including (1) application of chemical insecticides, (2) application of natural predators and, (3) improving crop resistance through plant genetics programs. Randomized field trials are used to determine the effectiveness of pest management programs. These trials frequently consist of randomly selected crop plots to which well-defined input regimes are instituted. For example, corn borers might be released onto crop plots in several densities at various stages of crop development, then sprayed with different levels of pesticide. These experiments are duplicated across regions and, in some cases across the country, to determine, in this instance for example, the best pesticide application rate for a given pest density and crop development stage. In order to release these pests onto crop plots, one must have an adequate supply of the insect pest. In winter months studies are carried out in the laboratory to examine chemical and natural pesticide effectiveness, as well as such things as the role of pheromones in moth behavior. The advantage in field trials is that yield data can be garnered directly. In this country, insects are raised for crop research primarily through the US Department of Agriculture, in cooperation with public Land Grant Universities and, by the private sector agricultural concerns - seed companies and others. This study quantifies the airborne allergen exposure of persons working in a Land Grant University entomology lab were allergy to European corn borer was suspected.

  12. Environmental assessment of a site contaminated by organic compounds.

    PubMed

    Riccardi, C; Berardi, S; Di Basilio, M; Gariazzo, C; Giardi, P; Villarini, M

    2001-01-01

    This paper presents a study on environmental assessment of an abandoned industrial area located in central Italy. Main production was refractory materials and compounds for treatment of industrial wastewater. The present work deals with a methodology for development of a sound sampling design, chemical characterization of soil samples, definition of the degree of site contamination according to law limits and evaluation of the fate and transport of contaminants by EPA simulation model (VLEACH 2.2a). Results indicate that toxic compounds (polycyclic aromatic hydrocarbons and plasticizers) are uniformly distributed in the contaminated site and only in one sampling point their concentrations exceed law limits. Modeling results confirm that contaminants migration to groundwater can be excluded, addressing for a site remediation limited to the surface layer.

  13. Geodetic Imaging for Rapid Assessment of Earthquakes: Airborne Laser Scanning (ALS)

    NASA Astrophysics Data System (ADS)

    Carter, W. E.; Shrestha, R. L.; Glennie, C. L.; Sartori, M.; Fernandez-Diaz, J.; National CenterAirborne Laser Mapping Operational Center

    2010-12-01

    To the residents of an area struck by a strong earthquake quantitative information on damage to the infrastructure, and its attendant impact on relief and recovery efforts, is urgent and of primary concern. To earth scientists a strong earthquake offers an opportunity to learn more about earthquake mechanisms, and to compare their models with the real world, in hopes of one day being able to accurately predict the precise locations, magnitudes, and times of large (and potentially disastrous) earthquakes. Airborne laser scanning (also referred to as airborne LiDAR or Airborne Laser Swath Mapping) is particularly well suited for rapid assessment of earthquakes, both for immediately estimating the damage to infrastructure and for providing information for the scientific study of earthquakes. ALS observations collected at low altitude (500—1000m) from a relatively slow (70—100m/sec) aircraft can provide dense (5—15 points/m2) sets of surface features (buildings, vegetation, ground), extending over hundreds of square kilometers with turn around times of several hours to a few days. The actual response time to any given event depends on several factors, including such bureaucratic issues as approval of funds, export license formalities, and clearance to fly over the area to be mapped, and operational factors such as the deployment of the aircraft and ground teams may also take a number of days for remote locations. Of course the need for immediate mapping of earthquake damage generally is not as urgent in remote regions with less infrastructure and few inhabitants. During August 16-19, 2010 the National Center for Airborne Laser Mapping (NCALM) mapped the area affected by the magnitude 7.2 El Mayor-Cucapah Earthquake (Northern Baja California Earthquake), which occurred on April 4, 2010, and was felt throughout southern California, Arizona, Nevada, and Baja California North, Mexico. From initial ground observations the fault rupture appeared to extend 75 km

  14. Assessing Organic Contaminant Fluxes from Contaminated Sediments Following Dam Removal in an Urbanized River

    EPA Science Inventory

    In this study, methods and approaches were developed and tested to assess changes in contaminant fluxes resulting from dam removal in a riverine system. Sediment traps and passive samplers were deployed to measure particulate and dissolved PAHs and PCBs in the water column prior...

  15. Passive sampling methods for contaminated sediments: risk assessment and management.

    PubMed

    Greenberg, Marc S; Chapman, Peter M; Allan, Ian J; Anderson, Kim A; Apitz, Sabine E; Beegan, Chris; Bridges, Todd S; Brown, Steve S; Cargill, John G; McCulloch, Megan C; Menzie, Charles A; Shine, James P; Parkerton, Thomas F

    2014-04-01

    This paper details how activity-based passive sampling methods (PSMs), which provide information on bioavailability in terms of freely dissolved contaminant concentrations (Cfree ), can be used to better inform risk management decision making at multiple points in the process of assessing and managing contaminated sediment sites. PSMs can increase certainty in site investigation and management, because Cfree is a better predictor of bioavailability than total bulk sediment concentration (Ctotal ) for 4 key endpoints included in conceptual site models (benthic organism toxicity, bioaccumulation, sediment flux, and water column exposures). The use of passive sampling devices (PSDs) presents challenges with respect to representative sampling for estimating average concentrations and other metrics relevant for exposure and risk assessment. These challenges can be addressed by designing studies that account for sources of variation associated with PSMs and considering appropriate spatial scales to meet study objectives. Possible applications of PSMs include: quantifying spatial and temporal trends in bioavailable contaminants, identifying and evaluating contaminant source contributions, calibrating site-specific models, and, improving weight-of-evidence based decision frameworks. PSM data can be used to assist in delineating sediment management zones based on likelihood of exposure effects, monitor remedy effectiveness, and, evaluate risk reduction after sediment treatment, disposal, or beneficial reuse after management actions. Examples are provided illustrating why PSMs and freely dissolved contaminant concentrations (Cfree ) should be incorporated into contaminated sediment investigations and study designs to better focus on and understand contaminant bioavailability, more accurately estimate exposure to sediment-associated contaminants, and better inform risk management decisions. Research and communication needs for encouraging broader use are discussed. PMID

  16. Passive sampling methods for contaminated sediments: risk assessment and management.

    PubMed

    Greenberg, Marc S; Chapman, Peter M; Allan, Ian J; Anderson, Kim A; Apitz, Sabine E; Beegan, Chris; Bridges, Todd S; Brown, Steve S; Cargill, John G; McCulloch, Megan C; Menzie, Charles A; Shine, James P; Parkerton, Thomas F

    2014-04-01

    This paper details how activity-based passive sampling methods (PSMs), which provide information on bioavailability in terms of freely dissolved contaminant concentrations (Cfree ), can be used to better inform risk management decision making at multiple points in the process of assessing and managing contaminated sediment sites. PSMs can increase certainty in site investigation and management, because Cfree is a better predictor of bioavailability than total bulk sediment concentration (Ctotal ) for 4 key endpoints included in conceptual site models (benthic organism toxicity, bioaccumulation, sediment flux, and water column exposures). The use of passive sampling devices (PSDs) presents challenges with respect to representative sampling for estimating average concentrations and other metrics relevant for exposure and risk assessment. These challenges can be addressed by designing studies that account for sources of variation associated with PSMs and considering appropriate spatial scales to meet study objectives. Possible applications of PSMs include: quantifying spatial and temporal trends in bioavailable contaminants, identifying and evaluating contaminant source contributions, calibrating site-specific models, and, improving weight-of-evidence based decision frameworks. PSM data can be used to assist in delineating sediment management zones based on likelihood of exposure effects, monitor remedy effectiveness, and, evaluate risk reduction after sediment treatment, disposal, or beneficial reuse after management actions. Examples are provided illustrating why PSMs and freely dissolved contaminant concentrations (Cfree ) should be incorporated into contaminated sediment investigations and study designs to better focus on and understand contaminant bioavailability, more accurately estimate exposure to sediment-associated contaminants, and better inform risk management decisions. Research and communication needs for encouraging broader use are discussed.

  17. Assessment of Airborne Exposures and Health in Flooded Homes Undergoing Renovation

    PubMed Central

    Hoppe, Kimberly A.; Metwali, Nervana; Perry, Sarah Spencer; Hart, Tom; Kostle, Pamela A.; Thorne, Peter S.

    2012-01-01

    In June 2008, the Cedar River crested flooding more than 5,000 Cedar Rapids homes. Residents whose homes were flooded were invited to participate in this study. Household assessments and resident interviews were conducted between November 2008 and April 2009. We characterized exposures and symptoms experienced by individuals inhabiting 73 flood-damaged homes. Active air sampling and passive electrostatic dust collectors were used to assess exposures to: culturable mold, culturable bacteria, fungal spores, inhalable particulate matter (iPM), endotoxin, glucans, allergens, lead, asbestos, radon, carbon dioxide, and carbon monoxide. Wall moisture levels and relative humidity were also measured. Exposures and questionnaire-based health assessments were compared at two levels of remediation, in-progress and completed. Homes with remediation in-progress (n=24), as compared to the completed homes (n=49), had significantly higher airborne concentrations of mold, bacteria, iPM, endotoxin and glucan. Residents of in-progress homes had a significantly higher prevalence of doctor diagnosed allergies (adjusted OR=3.08; 95%CI: 1.05–9.02) and all residents had elevated prevalence of self-reported wheeze (adjusted OR=3.77; 95%CI: 2.06–6.92) and prescription medication use for breathing problems (adjusted OR=1.38; 95%CI: 1.01–1.88) after the flood as compared to before. Proper post-flood remediation led to improved air quality and lower exposures among residents living in flooded homes. PMID:22519834

  18. A fuzzy areal assessment approach for potentially contaminated sites

    NASA Astrophysics Data System (ADS)

    Özdamar, Linet; Demirhan, Melek; Özpinar, Alper; Kilanç, Burak

    2000-04-01

    This article describes a new fuzzy areal site assessment approach in the detection of contaminated zones within a site which is under environmental investigation. Conventional techniques utilized in this field are mostly interpolation based. These methods interpolate the contaminant concentration values at unobserved locations using observed values. Unlike these interpolation techniques, the motivation of the approach introduced here consists of partitioning a given site into smaller sections. Partitioning is carried out iteratively where subregions of interest are divided into further smaller regions. This re-partitioning scheme leads to a dynamic grouping of observations, since areas of differing sizes and boundaries contain different sets of samples. The potential of an area to contain contaminated zones is assessed by a fuzzy measure which converts the data values in that area into an aggregate grade normalized on [0, 1]. Thus, this approach does not assume concentration values at unobserved locations, rather, an areal potential is evaluated.

  19. Detection of airborne bacteria in a duck production facility with two different personal air sampling devices for an exposure assessment.

    PubMed

    Martin, Elena; Dziurowitz, Nico; Jäckel, Udo; Schäfer, Jenny

    2015-01-01

    Prevalent airborne microorganisms are not well characterized in industrial animal production buildings with respect to their quantity or quality. To investigate the work-related microbial exposure, personal bioaerosol sampling during the whole working day is recommended. Therefore, bioaerosol sampling in a duck hatchery and a duck house with two personal air sampling devices, a filter-based PGP and a NIOSH particle size separator, was performed. Subsequent, quantitative and qualitative analyses were carried out with" culture independent methods. Total cell concentrations (TCC) determined via fluorescence microscopy showed no difference between the two devices. In average, 8 × 10(6) cells/m(3) were determined in the air of the duck hatchery and 5 × 10(7) cells/m(3) in the air of the duck house. A Generated Restriction Fragment Length Polymorphism (RFLP) pattern revealed deviant bacterial compositions comparing samples collected with both devices. Clone library analyses based on 16S rRNA gene sequence analysis from the hatchery's air showed 65% similarity between the two sampling devices. Detailed 16S rRNA gene sequence analyses showed the occurrence of bacterial species like Acinetobacter baumannii, Enterococcus faecalis, Escherichia sp., and Shigella sp.; and a group of Staphylococcus delphini, S. intermedius, and S. pseudintermedius that provided the evidence of potential exposure to risk group 2 bacteria at the hatchery workplace. Size fractionated sampling with the developed by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) device revealed that pathogenic bacteria would deposit in the inhalable, the thorax, and possibly alveolar dust fraction according to EN481. TCC analysis showed the deposition of bacterial cells in the third stage (< 1μm) at the NIOSH device which implies that bacteria can reach deep into the lungs and contaminate the alveolus after inhalation. Nevertheless, both personal sampling devices

  20. ASSESSING THE ALLERGIC POTENTIAL OF INDOOR AIR FUNGAL CONTAMINANTS

    EPA Science Inventory

    Assessing the Allergic Potential of Indoor Air Fungal Contaminants
    Marsha D W Ward1, Michael E Viana2, Yonjoo Chung3, Najwa Haykal-Coates1, Lisa B Copeland1, Steven H Gavett1, and MaryJane K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, CVM, Raleigh, NC, USA, 3 UNC, S...

  1. Incorporating Contaminant Bioavailability into Sediment Quality Assessment Frameworks

    EPA Science Inventory

    The recently adopted sediment quality assessment framework for evaluating bay and estuarine sediments in the State of California incorporates bulk sediment chemistry as a key line of evidence(LOE) but does not address the bioavailability of measured contaminants. Thus, the chemis...

  2. Toxicity assessment for RMA target contaminants. Volume 2. Endangerment assessment, RMA, task 35. Final draft report

    SciTech Connect

    1987-06-01

    This report is a detailed discussion of the evaluations performed to develop the toxicity assessment for RMA contaminants in soil. The objectives of the toxicity assessment are to: (1) determine the nature and extent of health and environmental hazards associated with exposure to contaminants present at the site and (2) identify a quantitative index of toxicity for each target contaminant, referred to in this assessment as DT. The toxicity assessment for the RMA target contaminants has been performed consistent with published EPA guidelines and addresses only human health hazards associated with contaminants in soil. Each toxicity profile is composed of seven sections: (1) summary; (2) chemical and physical properties; and (3) transport and fate.

  3. Nitrate contamination risk assessment in groundwater at regional scale

    NASA Astrophysics Data System (ADS)

    Daniela, Ducci

    2016-04-01

    Nitrate groundwater contamination is widespread in the world, due to the intensive use of fertilizers, to the leaking from the sewage network and to the presence of old septic systems. This research presents a methodology for groundwater contamination risk assessment using thematic maps derived mainly from the land-use map and from statistical data available at the national institutes of statistic (especially demographic and environmental data). The potential nitrate contamination is considered as deriving from three sources: agricultural, urban and periurban. The first one is related to the use of fertilizers. For this reason the land-use map is re-classified on the basis of the crop requirements in terms of fertilizers. The urban source is the possibility of leaks from the sewage network and, consequently, is linked to the anthropogenic pressure, expressed by the population density, weighted on the basis of the mapped urbanized areas of the municipality. The periurban sources include the un-sewered areas, especially present in the periurban context, where illegal sewage connections coexist with on-site sewage disposal (cesspools, septic tanks and pit latrines). The potential nitrate contamination map is produced by overlaying the agricultural, urban and periurban maps. The map combination process is very easy, being an algebraic combination: the output values are the arithmetic average of the input values. The groundwater vulnerability to contamination can be assessed using parametric methods, like DRASTIC or easier, like AVI (that involves a limited numbers of parameters). In most of cases, previous documents produced at regional level can be used. The pollution risk map is obtained by combining the thematic maps of the potential nitrate contamination map and the groundwater contamination vulnerability map. The criterion for the linkages of the different GIS layers is very easy, corresponding to an algebraic combination. The methodology has been successfully

  4. Temporal and Spatial Patterns of Airborne Contaminants Relative to Amphibian Population in Sequoia and Kings Canyon National Parks, California

    EPA Science Inventory

    Airborne agricultural pesticides are being transported many tens of kilometers to remote locations in mountain areas, and they have been implicated as a cause for recent, dramatic population declines of several amphibian species in such areas. The strongest case is for the mount...

  5. Tropical Airborne LiDAR for Landslide Assessment in Malaysia: a technical perspective

    NASA Astrophysics Data System (ADS)

    Abd Manap, Mohamad; Azhari Razak, Khamarrul; Mohamad, Zakaria; Ahmad, Azhari; Ahmad, Ferdaus; Mohamad Zin, Mazlan; A'zad Rosle, Qalam

    2015-04-01

    Malaysia has faced a substantial number of landslide events every year. Cameron Highlands, Pahang is one of the badly areas affected by slope failures characterized by extreme climate, rugged topographic and weathered geological structures in a tropical environment. A high frequency of landslide occurrence in the hilly areas is predominantly due to the geological materials, tropical monsoon seasons and uncontrolled agricultural activities. Therefore the Government of Malaysia through the Prime Minister Department has allocated a special budget to conduct national level hazard and risk mapping project through Minerals and Geoscience Department Malaysia, the Ministry of Natural Resources and Environment. The primary aim of this project is to provide slope hazard risk information for a better slope management in Malaysia. In addition this project will establish national infrastructure for geospatial information on the geological terrain and slope by emphasizing the disaster risk throughout the country. The areas of interest are located in the three different selected areas i.e. Cameron Highlands (275 square kilometers), Ipoh (200 square kilometers) and Cheras Kajang -- Batang kali (650 square kilometers). These areas are selected based on National Slope Master Plan (2009 -- 2023) that endorsed by Malaysia Government Cabinet. The national hazard and risk mapping project includes six parts of major tasks: (1) desk study and mobilization, (2) airborne LiDAR data acquisition and analysis, (3) field data acquisition and verification, (4) hazard and risk for natural terrain, (5) hazard and risk analysis for man-made slope and (6) Man-made slope mitigation/preventive measures. The project was authorized in September, 2014 and will be ended in March, 2016. In this paper, the main focus is to evaluate the suitability of integrated capability of airborne- and terrestrial LiDAR data acquisition and analysis, and also digital photography for regional landslide assessment. The

  6. Status and Assessment of Chesapeake Bay Wildlife Contamination

    USGS Publications Warehouse

    Heinz, G.H.; Wiemeyer, Stanley N.; Clark, D.R., Jr.; Albers, P.H.; Henry, P.; Batiuk, R.A.

    1992-01-01

    As an integral component of its priority setting process, the Chesapeake Bay Program`s Toxics Subcommittee has sought the expertise of Chesapeake Bay researchers and managers in developing a series of Chesapeake Bay toxics status and assessment papers. In the report, evidence for historical and current contaminant effects on key bird species, mammals, reptiles and amphibians which inhabit the Chesapeake Bay basin is examined. For each group of wildlife species, a general overview of effects caused by specific toxic substances is followed by detailed accounts of contaminant effects on selected species. Sponsored by Environmental Protection Agency, Annapolis, MD. Chesapeake Bay Program.

  7. Status and assessment of Chesapeake Bay wildlife contamination

    SciTech Connect

    Heinz, G.H.; Wiemeyer, S.N.; Clark, D.R.; Albers, P.; Henry, P.

    1992-10-01

    As an integral component of its priority setting process, the Chesapeake Bay Program's Toxics Subcommittee has sought the expertise of Chesapeake Bay researchers and managers in developing a series of Chesapeake Bay toxics status and assessment papers. In the report, evidence for historical and current contaminant effects on key bird species, mammals, reptiles and amphibians which inhabit the Chesapeake Bay basin is examined. For each group of wildlife species, a general overview of effects caused by specific toxic substances is followed by detailed accounts of contaminant effects on selected species.

  8. Assessment of environmental contaminant-induced lymphocyte dysfunction.

    PubMed Central

    Silkworth, J B; Loose, L D

    1981-01-01

    Although it has been established that environmental contaminants can alter immune function, the mechanisms of action have yet to be determined. This paper reviews the effects of hydrocarbon environmental contaminants on lymphocyte function and presents an approach which may serve to delineate the mechanisms of action. The approach is based on the use of the developmental phases of an immune response and assays which can be used for their functional assessment. Possible interactions between environmental contaminants and lymphocyte function and factors which must be considered in the evaluation of immune status are discussed. In addition, a study on the influence of the chronic exposure to two polyhalogenated hydrocarbons, PCB and HCB, on several parameters of lymphocyte function in mice is presented. PMID:7016518

  9. Application of real-time PCR for total airborne bacterial assessment: Comparison with epifluorescence microscopy and culture-dependent methods

    NASA Astrophysics Data System (ADS)

    Rinsoz, Thomas; Duquenne, Philippe; Greff-Mirguet, Guylaine; Oppliger, Anne

    Traditional culture-dependent methods to quantify and identify airborne microorganisms are limited by factors such as short-duration sampling times and inability to count non-culturable or non-viable bacteria. Consequently, the quantitative assessment of bioaerosols is often underestimated. Use of the real-time quantitative polymerase chain reaction (Q-PCR) to quantify bacteria in environmental samples presents an alternative method, which should overcome this problem. The aim of this study was to evaluate the performance of a real-time Q-PCR assay as a simple and reliable way to quantify the airborne bacterial load within poultry houses and sewage treatment plants, in comparison with epifluorescence microscopy and culture-dependent methods. The estimates of bacterial load that we obtained from real-time PCR and epifluorescence methods, are comparable, however, our analysis of sewage treatment plants indicate these methods give values 270-290 fold greater than those obtained by the "impaction on nutrient agar" method. The culture-dependent method of air impaction on nutrient agar was also inadequate in poultry houses, as was the impinger-culture method, which gave a bacterial load estimate 32-fold lower than obtained by Q-PCR. Real-time quantitative PCR thus proves to be a reliable, discerning, and simple method that could be used to estimate airborne bacterial load in a broad variety of other environments expected to carry high numbers of airborne bacteria.

  10. A Contamination Vulnerability Assessment for the Sacramento Area Groundwater Basin

    SciTech Connect

    Moran, J E; Hudson, G B; Eaton, G F; Leif, R

    2004-03-10

    In response to concerns expressed by the California Legislature and the citizenry of the State of California, the State Water Resources Control Board (SWRCB), implemented a program to assess groundwater quality, and provide a predictive capability for identifying areas that are vulnerable to contamination. The program was initiated in response to concern over public supply well closures due to contamination by chemicals such as MtBE from gasoline, and solvents from industrial operations. As a result of this increased awareness regarding groundwater quality, the Supplemental Report of the 1999 Budget Act mandated the SWRCB to develop a comprehensive ambient groundwater-monitoring plan, and led to the initiation of the Ambient Groundwater Monitoring and Assessment (GAMA) Program. The primary objective of the GAMA Program is to assess the water quality and to predict the relative susceptibility to contamination of groundwater resources throughout the state of California. Under the GAMA program, scientists from Lawrence Livermore National Laboratory (LLNL) collaborate with the SWRCB, the U.S. Geological Survey, the California Department of Health Services (DHS), and the California Department of Water Resources (DWR) to implement the groundwater assessment program in cooperation with local water purveyors. In 2001 and 2002, LLNL carried out this vulnerability study in the groundwater basin of Sacramento suburban area, located to the north of the American River and to the east of the Sacramento River. The goal of the study is to provide a probabilistic assessment of the relative vulnerability of groundwater used for the public water supply to contamination from surface sources. This assessment of relative contamination vulnerability is made based on the results of two types of analyses that are not routinely carried out at public water supply wells: ultra low-level measurement of volatile organic compounds (VOCs), and groundwater age dating (using the tritium-helium-3

  11. Potential of Multi-Temporal Oblique Airborne Imagery for Structural Damage Assessment

    NASA Astrophysics Data System (ADS)

    Vetrivel, A.; Duarte, D.; Nex, F.; Gerke, M.; Kerle, N.; Vosselman, G.

    2016-06-01

    Quick post-disaster actions demand automated, rapid and detailed building damage assessment. Among the available technologies, post-event oblique airborne images have already shown their potential for this task. However, existing methods usually compensate the lack of pre-event information with aprioristic assumptions of building shapes and textures that can lead to uncertainties and misdetections. However, oblique images have been already captured over many cities of the world, and the exploitation of pre- and post-event data as inputs to damage assessment is readily feasible in urban areas. In this paper, we investigate the potential of multi-temporal oblique imagery for detailed damage assessment focusing on two methodologies: the first method aims at detecting severe structural damages related to geometrical deformation by combining the complementary information provided by photogrammetric point clouds and oblique images. The developed method detected 87% of damaged elements. The failed detections are due to varying noise levels within the point cloud which hindered the recognition of some structural elements. We observed, in general that the façade regions are very noisy in point clouds. To address this, we propose our second method which aims to detect damages to building façades using the oriented oblique images. The results show that the proposed methodology can effectively differentiate among the three proposed categories: collapsed/highly damaged, lower levels of damage and undamaged buildings, using a computationally light-weight approach. We describe the implementations of the above mentioned methods in detail and present the promising results achieved using multi-temporal oblique imagery over the city of L'Aquila (Italy).

  12. Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 1999

    SciTech Connect

    DL Edwards; KD Shields; MJ Sula; MY Ballinger

    1999-09-28

    Assessments were performed to evaluate compliance with the airborne radionuclide emission monitoring requirements in the National Emission Standards for Hazardous Air Pollutants (NESHAP--US Code of Federal Regulations, Title 40 Part 61, Subpart H). In these assessments, potential unabated offsite doses were evaluated for emission locations at facilities owned by the US Department of Energy and operated by Pacific Northwest National Laboratory (Pacific Northwest) on the Hanford Site. Two of the facilities evaluated, 325 Building Radiochemical Processing Laboratory, and 331 Building Life Sciences Laboratory met state and federal criteria for continuous sampling of airborne radionuclide emissions. One other building, the 3720 Environmental Sciences Laboratory, was recognized as being in transition with the potential for meeting the continuous sampling criteria.

  13. Assessing airborne pollution effects on bryophytes: lessons learned through long-term integrated monitoring in Austria.

    PubMed

    Zechmeister, H G; Dirnböck, T; Hülber, K; Mirtl, M

    2007-06-01

    The study uses measured and calculated data on airborne pollutants, particularly nitrogen (ranges between 28 to 43kgN*ha(-1)*yr(-1)) and sulphur (10 to 18kgSO(4)-S*ha(-1)*yr(-1)), in order to assess their long-term (1992 to 2005) effects on bryophytes at the UN-ECE Integrated Monitoring site 'Zöbelboden' in Austria. Bryophytes were used as reaction indicators on 20 epiphytic plots using the IM monitoring method and on 14 terrestrial plots using standardised photography. The plots were recorded in the years 1992, 1993, 1998, and 2004/2005. Most species remained stable in terms of their overall population size during the observed period, even though there were rapid turnover rates of a large percentage of species on all investigated plots. Only a few bryophytes (Hypnum cupressiforme, Leucodon sciuroides) responded unambiguously to N and S deposition. Nitrogen deposition had a weak but significant effect on the distribution of bryophyte communities. However, the time shifts in bryophyte communities did not depend on total deposition of N and S.

  14. Airborne trace element pollution in 11 European cities assessed by exposure of standardised ryegrass cultures

    NASA Astrophysics Data System (ADS)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Breuer, Jörn; Vergne, Philippe; Sanz, María José; Rasmussen, Stine; Ro-Poulsen, Helge; Ribas Artola, Àngela; Peñuelas, Josep; He, Shang; Garrec, Jean Pierre; Calatayud, Vicent

    Within a European biomonitoring programme, Italian ryegrass ( Lolium multiflorum Lam.) was employed as accumulative bioindicator of airborne trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, V, Zn) in urban agglomerations. Applying a highly standardised method, grass cultures were exposed for consecutive periods of four weeks each to ambient air at up to 100 sites in 11 cities during 2000-2002. Results of the 2001 exposure experiments revealed a clear differentiation of trace element pollution within and among local monitoring networks. Pollution was influenced particularly by traffic emissions. Especially Sb, Pb, Cr, Fe, and Cu exhibited a very uneven distribution within the municipal areas with strong accumulation in plants from traffic-exposed sites in the city centres and close to major roads, and moderate to low levels in plants exposed at suburban or rural sites. Accumulation of Ni and V was influenced by other emission sources. The biomonitoring sites located in Spanish city centres featured a much higher pollution load by trace elements than those in other cities of the network, confirming previously reported findings obtained by chemical analyses of dust deposition and aerosols. At some heavily-trafficked sites, legal thresholds for Cu, Pb, and V contents in foodstuff and animal feed were reached or even surpassed. The study confirmed that the standardised grass exposure is a useful and reliable tool to monitor and to assess environmental levels of potentially toxic compounds of particulate matter.

  15. [Index assessment of airborne VOCs pollution in automobile for transporting passengers].

    PubMed

    Chen, Xiao-Kai; Cheng, He-Ming; Luo, Hui-Long

    2013-12-01

    Car for transporting passenger is the most common means of transport and in-car airborne volatile organic compounds (VOCs) cause harm to health. In order to analyze the pollution levels of benzene, toluene, ethylbenzene, xylenes, styrene and TVOC, index evaluation method was used according to the domestic and international standards of indoor and in-car air quality (IAQ). For Chinese GB/T 18883-2002 IAQ Standard, GB/T 17729-2009 Hygienic Standard for the Air Quality inside Long Distance Coach, GB/T 27630-2011 Guideline for Air Quality Assessment of Passenger Car, IAQ standard of South Korea, Norway, Japan and Germany, the heaviest pollution of VOCs in passenger car was TVOC, TVOC, benzene, benzene, TVOC, toluene and TVOC, respectively, the average pollution grade of automotive IAQ was median pollution, median pollution, clean, light pollution, median pollution, clean and heavy pollution, respectively. Index evaluation can effectively analyze vehicular interior air quality, and the result has a significant difference with different standards; German standard is the most stringent, while Chinese GB/T 18883-2002 standard is the relatively stringent and GB/T 27630-2011 is the most relaxed.

  16. Assessment of airborne asbestos exposure during the servicing and handling of automobile asbestos-containing gaskets.

    PubMed

    Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

    2006-07-01

    Five test sessions were conducted to assess asbestos exposure during the removal or installation of asbestos-containing gaskets on vehicles. All testing took place within an operative automotive repair facility involving passenger cars and a pickup truck ranging in vintage from late 1960s through 1970s. A professional mechanic performed all shop work including engine disassembly and reassembly, gasket manipulation and parts cleaning. Bulk sample analysis of removed gaskets through polarized light microscopy (PLM) revealed asbestos fiber concentrations ranging between 0 and 75%. Personal and area air samples were collected and analyzed using National Institute of Occupational Safety Health (NIOSH) methods 7400 [phase contrast microscopy (PCM)] and 7402 [transmission electron microscopy (TEM)]. Among all air samples collected, approximately 21% (n = 11) contained chrysotile fibers. The mean PCM and phase contrast microscopy equivalent (PCME) 8-h time weighted average (TWA) concentrations for these samples were 0.0031 fibers/cubic centimeters (f/cc) and 0.0017 f/cc, respectively. Based on these findings, automobile mechanics who worked with asbestos-containing gaskets may have been exposed to concentrations of airborne asbestos concentrations approximately 100 times lower than the current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 0.1 f/cc.

  17. Calibration Design and Assessment of the Airborne Conical Scanning Millimeterwave Imaging Radiometer (CoSMIR)

    NASA Technical Reports Server (NTRS)

    Piepmeier, J. R.; Racette, P.; Walker, D. K.; Randa, J.; Krebs, Carolyn A. (Technical Monitor)

    2002-01-01

    The airborne Conical Scanning Millimeter-wave Imaging Radiometer (CoSMIR) will provide measurements useful for atmospheric studies and satellite calibration and validation (cal/val). Designed to match the tropospheric sounding channels of the Defense Meteorological Satellite Program QMSP) Special Sensor Microwave Imager/Sounder (SSMIS), the CoSMIR consists of four radiometers operating at 50-54 (3 channels - 50.3, 52.8, and 53.6), 91.655 (dual polarization), 150.0, and 193.31 (3 channels 11, 13, and 16.6) GHz. The design of CoSMIR was primarily driven by its intended initial use as an SSMIS cal/val sensor. In particular, three design features were directly affected by this requirement: frequency planning, calibration target design, and the mechanical gimbals. An initial calibration assessment of CoSMIR was performed to determine any needed improvements. We used a combination of laboratory and field measurements to do this. Laboratory measurements included comparisons to a liquid nitrogen standard, IF amplifier and diode linearity tests, LO leakage and reflection testing, and antenna to calibration target coupling tests. Results of these tests will be reported. We also performed a satellite underflight under DM SP F-15 and have compared CoSMIR imagery to SSM/T-2 and SSM/I imagery. Additional information is included in the original extended abstract.

  18. Identification of contaminants of concern Columbia River Comprehensive Impact Assessment

    SciTech Connect

    Napier, B.A.; Batishko, N.C.; Heise-Craff, D.A.; Jarvis, M.F.; Snyder, S.F.

    1995-01-01

    The Columbia River Comprehensive Impact Assessment (CRCIA) Project at the Pacific Northwest Laboratory (PNL) is evaluating the current human and ecological risks from contaminants in the Columbia River. The risks to be studied are those attributable to past and present activities on the Hanford Site. The Hanford Site is located in southcentral Washington State near the town of Richland. Human risk from exposure to radioactive and hazardous materials will be addressed for a range of river use options. Ecological risk will be evaluated relative to the health of the current river ecosystem. The overall purpose of the project is to determine if enough contamination exists in the Columbia River to warrant cleanup actions under applicable environmental regulations. This report documents an initial review, from a risk perspective, of the wealth of historical data concerning current or potential contamination in the Columbia River. Sampling data were examined for over 600 contaminants. A screening analysis was performed to identify those substances present in such quantities that they may pose a significant human or ecological risk. These substances will require a more detailed analysis to assess their impact on humans or the river ecosystem.

  19. Quantitative Microbial Risk Assessment in Occupational Settings Applied to the Airborne Human Adenovirus Infection

    PubMed Central

    Carducci, Annalaura; Donzelli, Gabriele; Cioni, Lorenzo; Verani, Marco

    2016-01-01

    Quantitative Microbial Risk Assessment (QMRA) methodology, which has already been applied to drinking water and food safety, may also be applied to risk assessment and management at the workplace. The present study developed a preliminary QMRA model to assess microbial risk that is associated with inhaling bioaerosols that are contaminated with human adenovirus (HAdV). This model has been applied to air contamination data from different occupational settings, including wastewater systems, solid waste landfills, and toilets in healthcare settings and offices, with different exposure times. Virological monitoring showed the presence of HAdVs in all the evaluated settings, thus confirming that HAdV is widespread, but with different average concentrations of the virus. The QMRA results, based on these concentrations, showed that toilets had the highest probability of viral infection, followed by wastewater treatment plants and municipal solid waste landfills. Our QMRA approach in occupational settings is novel, and certain caveats should be considered. Nonetheless, we believe it is worthy of further discussions and investigations. PMID:27447658

  20. Quantitative Microbial Risk Assessment in Occupational Settings Applied to the Airborne Human Adenovirus Infection.

    PubMed

    Carducci, Annalaura; Donzelli, Gabriele; Cioni, Lorenzo; Verani, Marco

    2016-01-01

    Quantitative Microbial Risk Assessment (QMRA) methodology, which has already been applied to drinking water and food safety, may also be applied to risk assessment and management at the workplace. The present study developed a preliminary QMRA model to assess microbial risk that is associated with inhaling bioaerosols that are contaminated with human adenovirus (HAdV). This model has been applied to air contamination data from different occupational settings, including wastewater systems, solid waste landfills, and toilets in healthcare settings and offices, with different exposure times. Virological monitoring showed the presence of HAdVs in all the evaluated settings, thus confirming that HAdV is widespread, but with different average concentrations of the virus. The QMRA results, based on these concentrations, showed that toilets had the highest probability of viral infection, followed by wastewater treatment plants and municipal solid waste landfills. Our QMRA approach in occupational settings is novel, and certain caveats should be considered. Nonetheless, we believe it is worthy of further discussions and investigations. PMID:27447658

  1. Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 2007

    SciTech Connect

    Ballinger, Marcel Y.; Barfuss, Brad C.; Gervais, Todd L.

    2008-01-01

    Assessments were performed to evaluate compliance with the airborne radionuclide emission monitoring requirements in the National Emission Standards for Hazardous Air Pollutants (NESHAP – U.S. Code of Federal Regulations, Title 40, Part 61, Subpart H) and Washington Administrative Code (WAC) 246-247: Radiation Protection – Air Emissions. In these NESHAP assessments, potential unabated offsite doses were evaluated for emission locations at buildings that are part of the consolidated laboratory campus of the Pacific Northwest National Laboratory. This report describes the inventory-based methods and provides the results for the NESHAP assessment performed in 2007.

  2. Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 2010

    SciTech Connect

    Ballinger, Marcel Y.; Gervais, Todd L.; Barnett, J. Matthew

    2011-05-13

    Assessments were performed to evaluate compliance with the airborne radionuclide emission monitoring requirements in the National Emission Standards for Hazardous Air Pollutants ([NESHAP]; U.S. Code of Federal Regulations, Title 40, Part 61, Subpart H) and Washington Administrative Code 246-247: Radiation Protection - Air Emissions. In these NESHAP assessments, potential unabated off-site doses were evaluated for emission locations at buildings that are part of the consolidated laboratory campus of the Pacific Northwest National Laboratory. This report describes the inventory-based methods and provides the results for the NESHAP assessment performed in 2010.

  3. Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 2003

    SciTech Connect

    Ballinger, Marcel Y.; Sula, Monte J.; Gervais, Todd L.; Edwards, Daniel L.

    2003-12-05

    Assessments were performed to evaluate compliance with the airborne radionuclide emission monitoring requirements in the National Emission Standards for Hazardous Air Pollutants (NESHAP - U.S. Code of Federal Regulations, Title 40, Part 61, Subpart H) and Washington Administrative Code (WAC) 246-247: Radiation Protection - Air Emissions. In these assessments, potential unabated offsite doses were evaluated for emission locations at facilities owned by the U.S. Department of Energy and operated by Pacific Northwest National Laboratory (PNNL) on the Hanford Site. This report describes the inventory-based methods and provides the results for the assessment performed in 2003.

  4. Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 2001

    SciTech Connect

    Ballinger, Marcel Y.; Sula, Monte J.; Gervais, Todd L.; Shields, Keith D.; Edwards, Daniel R.

    2001-09-28

    Assessments were performed to evaluate compliance with the airborne radionuclide emission monitoring requirements in the National Emission Standards for Hazardous Air Pollutants (NESHAP - U.S. Code of Federal Regulations, Title 40 Part 61, Subpart H) and Washington Administrative Code (WAC) 246-247: Radiation Protection - Air Emissions. In these assessments, potential unabated offsite doses were evaluated for emission locations at facilities owned by the U.S. Department of Energy and operated by Pacific Northwest National Laboratory (PNNL) on the Hanford Site. This report describes the inventory-based methods, and provides the results, for the assessment performed in 2001.

  5. Importance of stationarity for geostatistical assessment of environmental contamination

    SciTech Connect

    Dagdelen, K.; Turner, A.K.

    1996-12-31

    This paper describes a geostatistical case study to assess TCE contamination from multiple point sources that is migrating through the geologically complex conditions with several aquifers. The paper highlights the importance of the stationarity assumption by demonstrating how biased assessments of TCE contamination result when ordinary kriging of the data that violates stationarity assumptions. Division of the data set into more homogeneous geologic and hydrologic zones improved the accuracy of the estimates. Indicator kriging offers an alternate method for providing a stochastic model that is more appropriate for the data. Further improvement in the estimates results when indicator kriging is applied to individual subregional data sets that are based on geological considerations. This further enhances the data homogeneity and makes use of stationary model more appropriate. By combining geological and geostatistical evaluations, more realistic maps may be produced that reflect the hydrogeological environment and provide a sound basis for future investigations and remediation.

  6. Gravity Anomaly Assessment Using Ggms and Airborne Gravity Data Towards Bathymetry Estimation

    NASA Astrophysics Data System (ADS)

    Tugi, A.; Din, A. H. M.; Omar, K. M.; Mardi, A. S.; Som, Z. A. M.; Omar, A. H.; Yahaya, N. A. Z.; Yazid, N.

    2016-09-01

    The Earth's potential information is important for exploration of the Earth's gravity field. The techniques of measuring the Earth's gravity using the terrestrial and ship borne technique are time consuming and have limitation on the vast area. With the space-based measuring technique, these limitations can be overcome. The satellite gravity missions such as Challenging Mini-satellite Payload (CHAMP), Gravity Recovery and Climate Experiment (GRACE), and Gravity-Field and Steady-State Ocean Circulation Explorer Mission (GOCE) has introduced a better way in providing the information on the Earth's gravity field. From these satellite gravity missions, the Global Geopotential Models (GGMs) has been produced from the spherical harmonics coefficient data type. The information of the gravity anomaly can be used to predict the bathymetry because the gravity anomaly and bathymetry have relationships between each other. There are many GGMs that have been published and each of the models gives a different value of the Earth's gravity field information. Therefore, this study is conducted to assess the most reliable GGM for the Malaysian Seas. This study covered the area of the marine area on the South China Sea at Sabah extent. Seven GGMs have been selected from the three satellite gravity missions. The gravity anomalies derived from the GGMs are compared with the airborne gravity anomaly, in order to figure out the correlation (R2) and the root mean square error (RMSE) of the data. From these assessments, the most suitable GGMs for the study area is GOCE model, GO_CONS_GCF_2_TIMR4 with the R2 and RMSE value of 0.7899 and 9.886 mGal, respectively. This selected model will be used in the estimating the bathymetry for Malaysian Seas in future.

  7. Soil slurry reactors for the assessment of contaminant biodegradation

    NASA Astrophysics Data System (ADS)

    Toscano, G.; Colarieti, M. L.; Greco, G.

    2012-04-01

    Slurry reactors are frequently used in the assessment of feasibility of biodegradation in natural soil systems. The rate of contaminant removal is usually quantified by zero- or first-order kinetics decay constants. The significance of such constants for the evaluation of removal rate in the field could be questioned because the slurry reactor is a water-saturated, well-stirred system without resemblance with an unsaturated fixed bed of soil. Nevertheless, a kinetic study with soil slurry reactors can still be useful by means of only slightly more sophisticated kinetic models than zero-/first-order decay. The use of kinetic models taking into account the role of degrading biomass, even in the absence of reliable experimental methods for its quantification, provides further insight into the effect of nutrient additions. A real acceleration of biodegradation processes is obtained only when the degrading biomass is in the growth condition. The apparent change in contaminant removal course can be useful to diagnose biomass growth without direct biomass measurement. Even though molecular biology techniques are effective to assess the presence of potentially degrading microorganism in a "viable-but-nonculturable" state, the attainment of conditions for growth is still important to the development of enhanced remediation techniques. The methodology is illustrated with reference to data gathered for two test sites, Oslo airport Gardermoen in Norway (continuous contamination by aircraft deicing fluids) and the Trecate site in Italy (aged contamination by crude oil spill). This research is part of SoilCAM project (Soil Contamination, Advanced integrated characterisation and time-lapse Monitoring 2008-2012, EU-FP7).

  8. Ecological risk assessment for river sediments contaminated by creosote

    SciTech Connect

    Pastorok, R.A.; Sampson, J.R.; Jacobson, M.A. ); Peek, D.C. )

    1994-12-01

    An ecological risk assessment was conducted for sediments of the lower Willamette River near a wood-treatment (creosote) facility. Both surface ad subsurface sediments near the facility are contaminated by polycyclic aromatic hydrocarbons (PAHs). Limited contamination of sediments by dioxins/furans, chlorinated phenols, and arsenic was also observed. Sediment bioassays based on amphipod (Hyalella azteca) mortality and Microtox[reg sign] (Photobacterium phosphoreum) bioluminescence showed toxicity within approximately 300 ft of the shoreline, with a highly toxic area (i.e., possible acute lethal effects in sedentary benthic species) near a dock used for creosote off-loading. The relatively low concentrations of contaminants measured in crayfish muscle tissue and the absence of serious lesions in livers of large-scale sucker collected near the site suggest that excess risk to mobile species from chronic contamination is low. Cursory observations indicate that acute toxic effects on crayfish may be associated with creosote seeps. There is no evidence of adverse biological effects throughout most of the main channel of the river. Evaluation of sediment chemistry data for PAHs relative to available sediment-quality criteria proposed by the US Environmental Protection Agency supports this conclusion.

  9. Public health risk assessment of groundwater contamination in Batman, Turkey.

    PubMed

    Nalbantcilar, M Tahir; Pinarkara, Sukru Yavuz

    2016-08-01

    In this study, a comprehensive analysis of groundwater was performed to assess contamination and phenol content in Batman, Turkey, particularly in residential areas near agriculture, livestock and oil industry facilities. From these areas, where potentially contaminated groundwater used for drinking and irrigation threatens public health, 30 groundwater samples were collected and analyzed for heavy metal concentrations (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Na, Ni, NO3, P, Pb, phenol, S, Sb, Se, SO4, Sr, U, and Zn). Compared with the standards of the Environmental Protection Agency, Al, Fe, and Mn concentrations in groundwater exceeded secondary drinking water regulations, NO3 concentrations were high for maximum contaminant levels, and As, Pb, and U concentrations exceeded maximum contaminant level goals in all samples. Ni, Sb, and Se concentrations also exceeded limits set by the Turkish Standards Institution. Nearly all samples revealed concentrations of Se, Sb, Hg, and phenol due to nearby petroleum refineries, oil storage plants, and agricultural and livestock areas. The results obtained from this study indicate that the groundwater in Batman contains elements in concentrations that approach or exceed limits and thus threatens public health with increased blood cholesterol, decreased blood sugar, and circulatory problems.

  10. Public health risk assessment of groundwater contamination in Batman, Turkey.

    PubMed

    Nalbantcilar, M Tahir; Pinarkara, Sukru Yavuz

    2016-08-01

    In this study, a comprehensive analysis of groundwater was performed to assess contamination and phenol content in Batman, Turkey, particularly in residential areas near agriculture, livestock and oil industry facilities. From these areas, where potentially contaminated groundwater used for drinking and irrigation threatens public health, 30 groundwater samples were collected and analyzed for heavy metal concentrations (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Na, Ni, NO3, P, Pb, phenol, S, Sb, Se, SO4, Sr, U, and Zn). Compared with the standards of the Environmental Protection Agency, Al, Fe, and Mn concentrations in groundwater exceeded secondary drinking water regulations, NO3 concentrations were high for maximum contaminant levels, and As, Pb, and U concentrations exceeded maximum contaminant level goals in all samples. Ni, Sb, and Se concentrations also exceeded limits set by the Turkish Standards Institution. Nearly all samples revealed concentrations of Se, Sb, Hg, and phenol due to nearby petroleum refineries, oil storage plants, and agricultural and livestock areas. The results obtained from this study indicate that the groundwater in Batman contains elements in concentrations that approach or exceed limits and thus threatens public health with increased blood cholesterol, decreased blood sugar, and circulatory problems. PMID:27441860

  11. Arsenic relative bioavailability from diet and airborne exposures: Implications for risk assessment.

    PubMed

    Yager, Janice W; Greene, Tracy; Schoof, Rosalind A

    2015-12-01

    Major human environmental health concern has been associated with inorganic arsenic (iAs) in drinking water in which dissolved iAs is highly bioavailable. More recently health concerns have been raised regarding the extent of iAs exposure via food and other potential sources. Arsenic relative bioavailability (RBA) in soil is known to be variable; the extent and role of iAs bioavailability in food are not well characterized. iAs in coal fly ash and bottom ash are other potential exposure media for which RBA has not been well characterized. A comprehensive literature search was conducted to support evaluation of the contribution of food and coal fly ash to iAs exposure. Few studies were found that investigated bioavailability associated with As-containing coal ash or airborne As-containing particles; estimated bioavailability in these studies ranged from 11% to 50%. The implications and potential usefulness of iAs bioavailability associated with inhalation exposure to human health risk assessment remain unknown at this time. Main sources of dietary iAs intake in the U.S. include rice and other grains, vegetables, and fruits. Due to low concentrations of iAs, seafood is not a primary contributor to dietary iAs intake. Three general kinds of food studies were identified: studies of As bioaccessibility in composites, As bioavailability and bioaccessibility in specific foods, and As consumption and urinary excretion in human volunteers. One in vivo study was identified that examined As bioavailability in food. A variety of experimental in vitro gastro-intestinal protocols have been used, however, few studies have included As speciation before and after the in vitro extraction. Current data suggest that the bioaccessibility of iAs in rice is quite high, typically 70% or more indicating that iAs in rice is highly bioavailable. Adjusting for RBA may not have a meaningful impact on iAs exposure estimates for rice-based foods. PMID:26225742

  12. An Assessment of Airborn Gravimetry Collected under the NGS GRAV-D Project

    NASA Astrophysics Data System (ADS)

    Holmes, S. A.

    2009-12-01

    In the United States, the National Geodetic Survey [NGS] holds the official charter to maintain the vertical datum for the USA and its territories. This includes the responsibility to maintain a current geoid model for transforming between orthometric (H) and geodetic (h) heights. The latest (2009) NGS geoid model incorporates the latest GRACE-based satellite-only geopotential solutions, very-high-resolution digital elevation models [DEMs] derived from the Shuttle Radar Topography Mission [SRTM], and other additional data and processing improvements. This recent geoid model also benefited greatly from the prior release of the National Geospatial-Intelligence Agency’s [NGA] Earth Gravitational Model 2008 [EGM2008], which served as a computational reference field for the new geoid, but was also particularly useful for identifying and removing corrupted data from the NGS gravimetry database. Looking forwards, NGS intends to increase its efforts to refine and improve its future national geoid models. To this end, their ambitious "Gravity for the Re-definition of the American Datum” [GRAV-D] project aims to update the NGS gravimetry holdings by flying new airborn gravity surveys over a large fraction of the USA and it territories. Concurrent efforts will focus on developing new processing techniques for optimally incorporating improved gravimetry into the final geoid solution. To this end, the GRAV-D team has already flown several surveys in the Gulf of Mexico, Puerto Rico, US Virgin Islands, and Alaska. Testing and analysis aimed at calibrating and validating the preliminary survey data is already underway. The latest assessment of these recent efforts, including the extent to which this new data can be expected to contribute to an improved gravimetric geoid model, is presented here.

  13. Vineyard zonal management for grape quality assessment by combining airborne remote sensed imagery and soil sensors

    NASA Astrophysics Data System (ADS)

    Bonilla, I.; Martínez De Toda, F.; Martínez-Casasnovas, J. A.

    2014-10-01

    Vineyard variability within the fields is well known by grape growers, producing different plant responses and fruit characteristics. Many technologies have been developed in last recent decades in order to assess this spatial variability, including remote sensing and soil sensors. In this paper we study the possibility of creating a stable classification system that better provides useful information for the grower, especially in terms of grape batch quality sorting. The work was carried out during 4 years in a rain-fed Tempranillo vineyard located in Rioja (Spain). NDVI was extracted from airborne imagery, and soil conductivity (EC) data was acquired by an EM38 sensor. Fifty-four vines were sampled at véraison for vegetative parameters and before harvest for yield and grape analysis. An Isocluster unsupervised classification in two classes was performed in 5 different ways, combining NDVI maps individually, collectively and combined with EC. The target vines were assigned in different zones depending on the clustering combination. Analysis of variance was performed in order to verify the ability of the combinations to provide the most accurate information. All combinations showed a similar behaviour concerning vegetative parameters. Yield parameters classify better by the EC-based clustering, whilst maturity grape parameters seemed to give more accuracy by combining all NDVIs and EC. Quality grape parameters (anthocyanins and phenolics), presented similar results for all combinations except for the NDVI map of the individual year, where the results were poorer. This results reveal that stable parameters (EC or/and NDVI all-together) clustering outcomes in better information for a vineyard zonal management strategy.

  14. Assessment of the Geodetic and Color Accuracy of Multi-Pass Airborne/Mobile Lidar Data

    NASA Astrophysics Data System (ADS)

    Pack, R. T.; Petersen, B.; Sunderland, D.; Blonquist, K.; Israelsen, P.; Crum, G.; Fowles, A.; Neale, C.

    2008-12-01

    The ability to merge lidar and color image data acquired by multiple passes of an aircraft or van is largely dependent on the accuracy of the navigation system that estimates the dynamic position and orientation of the sensor. We report an assessment of the performance of a Riegl Q560 lidar transceiver combined with a Litton LN-200 inertial measurement unit (IMU) based NovAtel SPAN GPS/IMU system and a Panasonic HD Video Camera system. Several techniques are reported that were used to maximize the performance of the GPS/IMU system in generating precisely merged point clouds. The airborne data used included eight flight lines all overflying the same building on the campus at Utah State University. These lines were flown at the FAA minimum altitude of 1000 feet for fixed-wing aircraft. The mobile data was then acquired with the same system mounted to look sideways out of a van several months later. The van was driven around the same building at variable speed in order to avoid pedestrians. An absolute accuracy of about 6 cm and a relative accuracy of less than 2.5 cm one-sigma are documented for the merged data. Several techniques are also reported for merging of the color video data stream with the lidar point cloud. A technique for back-projecting and burning lidar points within the video stream enables the verification of co-boresighting accuracy. The resulting pixel-level alignment is accurate with within the size of a lidar footprint. The techniques described in this paper enable the display of high-resolution colored points of high detail and color clarity.

  15. Assessment of fluoride contamination in groundwater as precursor for electrocoagulation.

    PubMed

    Sajil Kumar, P J

    2012-07-01

    The Present study was conducted in January 2010, in order to assess the fluoride contamination in the Thirupathur Taluk. The major objective of this study was to locate the vulnerable areas in terms of fluoride contamination. The range of fluoride concentration varied between .26 and 2.75 mg/L. 60 % of the samples were above the permissible limit. Good correlation was observed between pH, Na, HCO(3), CO(3) TDS and NO(3). A negative correlation showed by Ca and K. The results show that Geochemistry of these ions controls the Fluoride concentration in the study area. All the samples exceeded the permissible limit of F was characterized by Na-HCO(3) type of water. A fairly good correlation between F and NO(3) suggest an anthropogenic input of F, mainly from the agricultural fields. Spatial distribution map of Fluoride shows very high concentration in the SW part of the study area.

  16. Environmental assessment of three egg production systems - Part III: Airborne bacteria concentrations and emissions.

    PubMed

    Zhao, Y; Zhao, D; Ma, H; Liu, K; Atilgan, A; Xin, H

    2016-07-01

    Airborne microorganism level is an important indoor air quality indicator, yet it has not been well documented for laying-hen houses in the United States. As a part of the Coalition for Sustainable Egg Supply (CSES) environmental monitoring project, this study comparatively monitored the concentrations and emissions of airborne total and Gram-negative (Gram(-)) bacteria in three types of commercial laying-hen houses, i.e., conventional cage (CC), aviary (AV), and enriched colony (EC) houses, over a period of eight months covering the mid and late stages of the flock cycle. It also delineated the relationship between airborne total bacteria and particulate matter smaller than 10 μm in aerodynamic diameter (PM10). The results showed airborne total bacteria concentrations (log CFU/m(3)) of 4.7 ± 0.3 in CC, 6.0 ± 0.8 in AV, and 4.8 ± 0.3 in EC, all being higher than the level recommended for human environment (3.0 log CFU/m(3)). The much higher concentrations in AV arose from the presence of floor litter and hen activities on it, as evidenced by the higher concentrations in the afternoon (with litter access) than in the morning (without litter access). The overall means and standard deviation of airborne total bacteria emission rates, in log CFU/[h-hen] (or log CFU/[h-AU], AU = animal unit or 500 kg live weight) were 4.8 ± 0.4 (or 7.3 ± 0.4) for CC, 6.1 ± 0.7 (or 8.6 ± 0.7) for AV, and 4.8 ± 0.5 (or 7.3 ± 0.5) for EC. Both concentration and emission rate of airborne total bacteria were positively related to PM10 Gram(-) bacteria were present at low concentrations in all houses; and only 2 samples (6%) in CC, 7 (22%) samples in AV, and 2 (6%) samples in EC out of 32 air samples collected in each house were found positive with Gram(-) bacteria. The concentration of airborne Gram(-) bacteria was estimated to be <2% of the total bacteria. Total bacteria counts in manure on belt (in all houses) and floor litter (only in AV) were similar; however, the manure had

  17. Regional risk assessment for contaminated sites part 1: vulnerability assessment by multicriteria decision analysis.

    PubMed

    Zabeo, A; Pizzol, L; Agostini, P; Critto, A; Giove, S; Marcomini, A

    2011-11-01

    As highlighted in the EU Soil Communication, local contamination is one of the main soil threats and it is often related to present and past industrial activities which left a legacy of a high number of contaminated sites in Europe. These contaminated sites can be harmful to many different receptors according to their sensitivity/susceptibility to contamination, and specific vulnerability evaluations are needed in order to manage this widely spread environmental issue. In this paper a novel comprehensive vulnerability assessment framework to assess regional receptor susceptibility to contaminated site is presented. The developed methodology, which combines multi criteria decision analysis (MCDA) techniques and spatial analysis, can be applied to different receptors recognized as relevant for regional assessment. In order to characterize each receptor, picked parameters significant for the estimation of the vulnerability to contaminated sites have been selected, normalized and aggregated by means of multi criteria decision analysis (MCDA) techniques. The developed MCDA methodology, based on the Choquet integral, allows to include expert judgments for the elicitation of synergic and conflicting effects between involved criteria and is applied to all the geographical objects representing the identified receptors. To test the potential of the vulnerability methodology, it has been applied to a specific case study area in the upper Silesia region of Poland where it proved to be reliable and consistent with the environmental experts' expected results. The vulnerability assessment results indicate that groundwater is the most vulnerable receptor characterized by a wide area with vulnerability scores belonging to the highest vulnerability class. As far as the other receptors are concerned, human health and surface water are characterized by quite homogeneous vulnerability scores falling in the medium-high vulnerability classes, while protected areas resulted to be the less

  18. Assessing organic contaminant fluxes from contaminated sediments following dam removal in an urbanized river.

    PubMed

    Cantwell, Mark G; Perron, Monique M; Sullivan, Julia C; Katz, David R; Burgess, Robert M; King, John

    2014-08-01

    In this study, methods and approaches were developed and tested to assess changes in contaminant fluxes resulting from dam removal in a riverine system. Sediment traps and passive samplers were deployed to measure particulate and dissolved polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the water column prior to and following removal of a small, low-head dam in the Pawtuxet River, an urbanized river located in Cranston, RI, USA. During the study, concentrations of particulate and dissolved PAHs ranged from 21.5 to 103 μg/g and from 68 to 164 ng/L, respectively. Overall, temporal trends of PAHs showed no increases in either dissolved or particulate phases following removal of the dam. Dissolved concentrations of PCBs were very low, remaining below 1.72 ng/L at all sites. Particulate PCB concentrations across sites and time showed slightly greater variability, ranging from 80 to 469 ng/g, but with no indication that dam removal influenced any increases. Particulate PAHs and PCBs were sampled continuously at the site located below the dam and did not show sustained increases in concentration resulting from dam removal. The employment of passive sampling technology and sediment traps was highly effective in monitoring the concentrations and flux of contaminants moving through the river system. Variations in river flow had no effect on the concentration of contaminants in the dissolved or particulate phases, but did influence the flux rate of contaminants exiting the river. Overall, dam removal did not cause measurable sediment disturbance or increase the concentration or fluxes of dissolved or particulate PAHs and PCBs. This is due in large part to low volumes of impounded sediment residing above the dam and highly armored sediments in the river channel, which limited erosion. Results from this study will be used to improve methods and approaches that assess the short- and long-term impacts ecological restoration activities such as

  19. Use of airborne remote sensing to detect riverside Brassica rapa to aid in risk assessment of transgenic crops

    NASA Astrophysics Data System (ADS)

    Elliott, Luisa M.; Mason, David C.; Allainguillaume, Joel; Wilkinson, Mike J.

    2009-11-01

    High resolution descriptions of plant distribution have utility for many ecological applications but are especially useful for predictive modeling of gene flow from transgenic crops. Difficulty lies in the extrapolation errors that occur when limited ground survey data are scaled up to the landscape or national level. This problem is epitomized by the wide confidence limits generated in a previous attempt to describe the national abundance of riverside Brassica rapa (a wild relative of cultivated rapeseed) across the United Kingdom. Here, we assess the value of airborne remote sensing to locate B. rapa over large areas and so reduce the need for extrapolation. We describe results from flights over the river Nene in England acquired using Airborne Thematic Mapper (ATM) and Compact Airborne Spectrographic Imager (CASI) imagery, together with ground truth data. It proved possible to detect 97% of flowering B. rapa on the basis of spectral profiles. This included all stands of plants that occupied >2m square (>5 plants), which were detected using single-pixel classification. It also included very small populations (<5 flowering plants, 1-2m square) that generated mixed pixels, which were detected using spectral unmixing. The high detection accuracy for flowering B. rapa was coupled with a rather large false positive rate (43%). The latter could be reduced by using the image detections to target fieldwork to confirm species identity, or by acquiring additional remote sensing data such as laser altimetry or multitemporal imagery.

  20. Assessment of chlorophyll-a concentration in the Gulf of Riga using hyperspectral airborne and simulated Sentinel-3 OLCI data

    NASA Astrophysics Data System (ADS)

    Jakovels, Dainis; Brauns, Agris; Filipovs, Jevgenijs; Taskovs, Juris; Fedorovicha, Dagnija; Paavel, Birgot; Ligi, Martin; Kutser, Tiit

    2016-08-01

    Remote sensing has proved to be an accurate and reliable tool in clear water environments like oceans or the Mediterranean Sea. However, the current algorithms and methods usually fail on optically complex waters like coastal and inland waters. The whole Baltic Sea can be considered as optically complex coastal waters. Remote assessment of water quality parameters (eg., chlorophyll-a concentration) is of interest for monitoring of marine environment, but hasn't been used as a routine approach in Latvia. In this study, two simultaneous hyperspectral airborne data and in situ measurement campaigns were performed in the Gulf of Riga near the River Daugava mouth in summer 2015 to simulate Sentinel-3 data and test existing algorithms for retrieval of Level 2 Water products. Comparison of historical data showed poor overall correlation between in situ measurements and MERIS chlorophyll-a data products. Better correlation between spectral chl-a data products and in situ water sampling measurements was achieved during simultaneous airborne and field campaign resulting in R2 up to 0.94 for field spectral data, R2 of 0.78 for airborne data. Test of all two band ratio combinations showed that R2 could be improved from 0.63 to 0.94 for hyperspectral airborne data choosing 712 and 728 nm bands instead of 709 and 666 nm, and R2 could be improved from 0.61 to 0.83 for simulated Sentinel-3 OLCI data choosing Oa10 and Oa8 bands instead of Oa11 and Oa8. Repeated campaigns are planned during spring and summer blooms 2016 in the Gulf of Riga to get larger data set for validation and evaluate repeatability. The main challenges remain to acquire as good data as possible within rapidly changing environment and often cloudy weather conditions.

  1. TXRF analysis of soils and sediments to assess environmental contamination.

    PubMed

    Bilo, Fabjola; Borgese, Laura; Cazzago, Davide; Zacco, Annalisa; Bontempi, Elza; Guarneri, Rita; Bernardello, Marco; Attuati, Silvia; Lazo, Pranvera; Depero, Laura E

    2014-12-01

    Total reflection x-ray fluorescence spectroscopy (TXRF) is proposed for the elemental chemical analysis of crustal environmental samples, such as sediments and soils. A comparative study of TXRF with respect to flame atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy was performed. Microwave acid digestion and suspension preparation methods are evaluated. A good agreement was found among the results obtained with different spectroscopic techniques and sample preparation methods for Cr, Mn, Fe, Ni, Cu, and Zn. We demonstrated that TXRF is suitable for the assessment of environmental contamination phenomena, even if the errors for Pb, As, V, and Ba are ingent.

  2. Mercury contamination and exposure assessment of fishery products in Korea.

    PubMed

    Yang, Hye-Ran; Kim, Na-Young; Hwang, Lae-Hong; Park, Ju-Sung; Kim, Jung-Hun

    2015-01-01

    In this study, total (T-Hg) and methyl mercury (Me-Hg) contamination was investigated in fishery products including canned fish, fish sauces, dried bonito and frozen tuna sashimi, collected from retail markets in Korea, to assess dietary exposure. Direct mercury analyser and gas chromatography-electron captured detector were employed to measure T-Hg and Me-Hg, respectively. The highest T-Hg and Me-Hg contamination was present in tuna sashimi, followed by dried bonito, respectively. Canned tuna showed more frequent detection and higher content than other canned fishery products. The weekly exposure estimate indicates that exposure to mercury from fishery products is safe, showing 2.59% provisional tolerable weekly intake (PTWI) for T-Hg, 1.82% PTWI for Me-Hg and 4.16% reference dose for Me-Hg. However, it should be addressed to monitor the mercury contamination in fish and fishery products regularly, to safeguard vulnerable population such as children, to limit intake of these food products.

  3. Mercury contamination and exposure assessment of fishery products in Korea.

    PubMed

    Yang, Hye-Ran; Kim, Na-Young; Hwang, Lae-Hong; Park, Ju-Sung; Kim, Jung-Hun

    2015-01-01

    In this study, total (T-Hg) and methyl mercury (Me-Hg) contamination was investigated in fishery products including canned fish, fish sauces, dried bonito and frozen tuna sashimi, collected from retail markets in Korea, to assess dietary exposure. Direct mercury analyser and gas chromatography-electron captured detector were employed to measure T-Hg and Me-Hg, respectively. The highest T-Hg and Me-Hg contamination was present in tuna sashimi, followed by dried bonito, respectively. Canned tuna showed more frequent detection and higher content than other canned fishery products. The weekly exposure estimate indicates that exposure to mercury from fishery products is safe, showing 2.59% provisional tolerable weekly intake (PTWI) for T-Hg, 1.82% PTWI for Me-Hg and 4.16% reference dose for Me-Hg. However, it should be addressed to monitor the mercury contamination in fish and fishery products regularly, to safeguard vulnerable population such as children, to limit intake of these food products. PMID:25249274

  4. Assessment of electrical charge on airborne microorganisms by a new bioaerosol sampling method.

    PubMed

    Lee, Shu-An; Willeke, Klaus; Mainelis, Gediminas; Adhikari, Atin; Wang, Hongxia; Reponen, Tiina; Grinshpun, Sergey A

    2004-03-01

    Bioaerosol sampling is necessary to monitor and control human exposure to harmful airborne microorganisms. An important parameter affecting the collection of airborne microorganisms is the electrical charge on the microorganisms. Using a new design of an electrostatic precipitator (ESP) for bioaerosol sampling, the polarity and relative strength of the electrical charges on airborne microorganisms were determined in several laboratory and field environments by measuring the overall physical collection efficiency and the biological collection efficiency at specific precipitation voltages and polarities. First, bacteria, fungal spores, and dust dispersed from soiled carpets were sampled in a walk-in test chamber. Second, a simulant of anthrax-causing Bacillus anthracis spores was dispersed and sampled in the same chamber. Third, bacteria were sampled in a small office while four adults were engaged in lively discussions. Fourth, bacteria and fungal spores released from hay and horse manure were sampled in a horse barn during cleanup operations. Fifth, bacteria in metalworking fluid droplets were sampled in a metalworking simulator. It was found that the new ESP differentiates between positively and negatively charged microorganisms, and that in most of the tested environments the airborne microorganisms had a net negative charge. This adds a signature to the sampled microorganisms that may assist in their identification or differentiation, for example, in an anti-bioterrorism network.

  5. Using mosaicked airborne imagery to assess cotton root rot infection on a regional basis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton root rot is a serious and destructive disease in many of the cotton production areas in Texas. Since 2012, many cotton growers in Texas have used the Topguard fungicide to control this disease in their fields under Section 18 emergency exemptions. Airborne images have been used to monitor the...

  6. 78 FR 44625 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... June 5, 2013 (78 FR 33894), and posting the draft questionnaire that was the subject of that notice, on... 5, 2013, VA published a notice in the Federal Register (78 FR 33894) (FR Doc. 2013-13224) announcing... AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne Hazard...

  7. Accuracy assessment of airborne photogrammetrically derived high-resolution digital elevation models in a high mountain environment

    NASA Astrophysics Data System (ADS)

    Müller, Johann; Gärtner-Roer, Isabelle; Thee, Patrick; Ginzler, Christian

    2014-12-01

    High-resolution digital elevation models (DEMs) generated by airborne remote sensing are frequently used to analyze landform structures (monotemporal) and geomorphological processes (multitemporal) in remote areas or areas of extreme terrain. In order to assess and quantify such structures and processes it is necessary to know the absolute accuracy of the available DEMs. This study assesses the absolute vertical accuracy of DEMs generated by the High Resolution Stereo Camera-Airborne (HRSC-A), the Leica Airborne Digital Sensors 40/80 (ADS40 and ADS80) and the analogue camera system RC30. The study area is located in the Turtmann valley, Valais, Switzerland, a glacially and periglacially formed hanging valley stretching from 2400 m to 3300 m a.s.l. The photogrammetrically derived DEMs are evaluated against geodetic field measurements and an airborne laser scan (ALS). Traditional and robust global and local accuracy measurements are used to describe the vertical quality of the DEMs, which show a non Gaussian distribution of errors. The results show that all four sensor systems produce DEMs with similar accuracy despite their different setups and generations. The ADS40 and ADS80 (both with a ground sampling distance of 0.50 m) generate the most accurate DEMs in complex high mountain areas with a RMSE of 0.8 m and NMAD of 0.6 m They also show the highest accuracy relating to flying height (0.14‰). The pushbroom scanning system HRSC-A produces a RMSE of 1.03 m and a NMAD of 0.83 m (0.21‰ accuracy of the flying height and 10 times the ground sampling distance). The analogue camera system RC30 produces DEMs with a vertical accuracy of 1.30 m RMSE and 0.83 m NMAD (0.17‰ accuracy of the flying height and two times the ground sampling distance). It is also shown that the performance of the DEMs strongly depends on the inclination of the terrain. The RMSE of areas up to an inclination <40° is better than 1 m. In more inclined areas the error and outlier occurrence

  8. [Risk assessment of quaternary groundwater contamination in Beijing Plain].

    PubMed

    Guo, Gao-Xuan; Li, Yu; Xu, Liang; Li, Zhi-Ping; Yang, Qing; Xu, Miao-Juan

    2014-02-01

    Firstly, advances in investigation and evaluation of groundwater pollution in China in the last decade were presented, and several issues in the field which hinder the development of groundwater environment were pointed out. Then, four key concepts in risk assessment of groundwater pollution were briefly described with more emphasis on the difference between groundwater pollution assessment and groundwater quality assessment in this paper. After that, a method on risk assessment of groundwater pollution which included four indicators, the pollution assessment, the quality assessment, the vulnerability and the pollution load of groundwater, was presented based on the regional characteristics of Beijing Plain. Also, AHP and expert scoring method were applied to determine the weight of the four evaluation factors. Finally, the application of this method in Beijing Plain showed the area with high, relative high, medium, relative low and low risk of groundwater contamination was 1 232.1 km2, 699.3 km2, 1 951.4 km, 2 644 km2, and 133.2 km2, respectively. The study results showed that the higher risk in the western region was likely caused by the higher pollution load and its higher vulnerability, while the relatively high risk in the southeast of Beijing plain area, the Tongzhou District, is mainly caused by historical pollution sources.

  9. Contaminants as viral cofactors: assessing indirect population effects

    USGS Publications Warehouse

    Springman, Katherine R.; Kurath, Gael; Anderson, James J.; Emlen, John M.

    2005-01-01

    Current toxicological methods often miss contaminant effects, particularly when immune suppression is involved. The failure to recognize and evaluate indirect and sublethal effects severely limits the applicability of those methods at the population level. In this study, the Vitality model is used to evaluate the population level effects of a contaminant exerting only indirect, sublethal effects at the individual level. Juvenile rainbow trout (Oncorhynchus mykiss) were injected with 2.5 or 10.0 mg/kg doses of the model CYP1A inducer, β-naphthoflavone (BNF) as a pre-stressor, then exposed to a challenge dose of 102 or 104 pfu/fish of infectious hematopoietic necrosis virus (IHNV), an important viral pathogen of salmonids in North America. At the end of the 28-d challenge, the mortality data were processed according to the Vitality model which indicated that the correlation between the average rate of vitality loss and the pre-stressor dose was strong:R2 = 0.9944. Average time to death and cumulative mortality were dependent on the BNF dose, while no significant difference between the two viral dosages was shown, implying that the history of the organism at the time of stressor exposure is an important factor in determining the virulence or toxicity of the stressor. The conceptual framework of this model permits a smoother transfer of results to a more complex stratum, namely the population level, which allows the immunosuppressive results generated by doses of a CYP1A inducer that more accurately represent the effects elicited by environmentally-relevant contaminant concentrations to be extrapolated to target populations. The indirect effects of other environmental contaminants with similar biotransformation pathways, such as polycyclic aromatic hydrocarbons (PAH), could be assessed and quantified with this model and the results applied to a more complex biological hierarchy.

  10. Assessment of sampling strategy for explosives-contaminated soils

    SciTech Connect

    Thiboutot, S.; Ampleman, G.; Jenkins, T.F.; Walsh, M.E.; Thorne, P.G.; Ranney, T.A.; Grant, C.L.

    1997-12-31

    An explosives-contaminated site was characterized using composite sampling, in-field sample homogenization and on-site analysis. Explosives contaminated sites demonstrate large short-range heterogeneity due to the crystalline nature and poor water solubility of the dispersed contaminants. The sampling strategy must be carefully planned in order to minimize sampling error and total uncertainty. The site investigated in this particular study is an anti-tank firing range that has been in-use for over 20 years. The ammunition fired at this range is a melt-cast explosive based on a mixture of HMX and TNT in the ratio of 70:30. Two previous preliminary sampling surveys of this site have shown high levels of HMX in soil samples collected nearby the targeted tanks. This particular site was chosen for a collaborative effort between the Canadian Department of National Defence and the USA Department of Defense to study sampling strategies and sample heterogeneity where HMX is the main contaminant. On-site colorimetric TNT and HMX methods and enzyme immunoassay TNT and RDX methods were used initially to evaluate if the sampling pattern used provided representative results. A 6 m square grid (36 m{sup 2}) pattern was established, including two of the targeted tanks. Seventeen grids were installed and composite samples were collected within those grids. Four surface composite samples were collected in each quadrant of each grid using a circular pattern that sampled about 10% of the top 5 cm of the surface. Replicates were collected to assess the representativeness achieved. Field analysis showed concentrations of HMX ranged from as high as 1640 mg/kg near one target to 2.1 mg/kg at a distance of 15 m from the target. On the other hand, TNT concentrations were much lower than would be expected based on the 70:30 composition ratio. Results from the colorimetric on-site analyses were in excellent agreement with laboratory results.

  11. NARAC: An Emergency Response Resource for Predicting the Atmospheric Dispersion and Assessing the Consequences of Airborne Radionuclides

    SciTech Connect

    Bradley, M M

    2005-08-23

    Hazardous radioactive materials can be released into the atmosphere by accidents at nuclear power plants, fuel processing facilities, and other facilities, and by transportation accidents involving nuclear materials. In addition, the post-cold-war proliferation of nuclear material has increased the potential for terrorism scenarios involving radiological dispersal devices, improvised nuclear devices, and inadequately secured military nuclear weapons. To mitigate these risks, the National Atmospheric Release Advisory Center (NARAC) serves as a national resource for the United States, providing tools and services to quickly predict the environmental contamination and health effects caused by airborne radionuclides, and to provide scientifically based guidance to emergency managers for the protection of human life. NARAC's expert staff uses computer models, supporting databases, software systems, and communications systems to predict the plume paths and consequences of radiological, chemical, and biological atmospheric releases.

  12. Quantitative airborne assessment of gas flaring combustion efficiency in the Bakken Shale

    NASA Astrophysics Data System (ADS)

    Gvakharia, A.; Kort, E. A.; Sweeney, C.; Peischl, J.; Ryerson, T. B.; Brandt, A. R.; Smith, M. L.

    2015-12-01

    The Bakken shale formation in North Dakota is a prolific source of oil and natural gas, producing 361 million barrels of oil in 2014. Drilling activities in the Bakken largely focus on oil, though co-production of natural gas is abundant. Up to 1/3 of the natural gas produced in this play is not captured, but is instead flared. The US EPA considers flare combustion efficiency to be 98%, indicating fugitive emissions of 2% of flared natural gas due to incomplete combustion. Studies of flaring combustion efficiency have been primarily laboratory-based, with minimal real-world analysis in the field. A recent study [Caulton et al., 2014] analyzed ten flares in the Bakken and found extremely high combustion efficiency of over 99.8%.Differences between this field study and the EPA standard have potentially significant implications for methane emissions from flaring, but given the small sample size, further in-field sampling is needed to quantify combustion efficiency in real conditions and assess why it may be different from laboratory studies.Here we will present a study on flaring combustion efficiency of methane and ethane in the Bakken field using continuous in-situ airborne observations of methane, ethane, and carbon dioxide. Over thirty flare plumes were observed during a three-week period in the Bakken formation in May 2014 in a range of wind conditions. For each flare we calculate the destruction efficiency and emission factors for methane and ethane. Preliminary results suggest combustion efficiency comparable with the EPA value of 98%, notably lower than the previous study. In addition, we calculate the corresponding mass flux of methane from incomplete flare combustion for the entire field using gas flare volume information and compare to the total emissions from the field calculated using our flight data and a mass-balance approach. Using the combustion efficiency from our study suggests methane emissions from incomplete combustion during flaring could be

  13. Levels and risk assessment for humans and ecosystems of platinum-group elements in the airborne particles and road dust of some European cities.

    PubMed

    Gómez, B; Palacios, M A; Gómez, M; Sanchez, J L; Morrison, G; Rauch, S; McLeod, C; Ma, R; Caroli, S; Alimonti, A; Petrucci, E; Bocca, B; Schramel, P; Zischka, M; Petterson, C; Wass, U

    2002-11-01

    Traffic is the main source of platinum-group element (PGE) contamination in populated urban areas. There is increasing concern about the hazardous effects of these new pollutants for people and for other living organisms in these areas. Airborne and road dusts, as well as tree bark and grass samples were collected at locations in the European cities of Göteborg (Sweden), Madrid (Spain), Rome (Italy), Munich (Germany), Sheffield and London (UK). Today, in spite of the large number of parameters that can influence the airborne PGE content, the results obtained so far indicate significantly higher PGE levels at traffic sites compared with the rural or non-polluted zones that have been investigated (background levels). The average Pt content in airborne particles found in downtown Madrid, Göteborg and Rome is in the range 7.3-13.1 pg m(-3). The ring roads of these cities have values in the range 4.1-17.7 pg m(-3). In Munich, a lower Pt content was found in airborne particles (4.1 pg m(-3)). The same tendency has been noted for downtown Rh, with contents in the range 2.2-2.8 pg m(-3), and in the range 0.8-3.0 and 0.3 pg m(-3) for motorway margins in Munich. The combined results obtained using a wide-range airborne classifier (WRAC) collector and a PM-10 or virtual impactor show that Pt is associated with particles for a wide range of diameters. The smaller the particle size, the lower the Pt concentration. However, in particles

  14. ASSESSING CONTAMINANT SENSITIVITY OF ENDANGERED AND THREATENED AQUATIC SPECIES WITH ACUTE TOXICITY TESTS

    EPA Science Inventory

    Assessment of contaminant impacts to endangered and threatened (listed) species requires understanding of a species' sensitivity to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation...

  15. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site in Lakeview, Oregon

    SciTech Connect

    Not Available

    1994-10-01

    This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site in Lake view, Oregon evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site.

  16. ASSESSMENT OF STACHYBOTRYS REGROWTH ON CONTAMINATED WALLBOARD AFTER TREATMENT WITH COMMON SURFACE CLEANERS/DISINFECTANTS

    EPA Science Inventory

    The paper describes results of experiments assessing the efficacy of treating mold-contaminated gypsum wallboard with cleaners and/or disinfectants. Although the accepted recommendations for handling Stachybotrys chartarum contaminated gypsum wallboard are removal and replacement...

  17. Assessing the bioavailability and risk from metal-contaminated soils and dusts

    EPA Science Inventory

    Exposure to contaminated soil and dust is an important pathway in human health risk assessment. Physical and chemical characteristics, as well as biological factors, determine the bioaccessibility/bioavailability of soil and dust contaminants. Within a single sample, contaminat...

  18. Incorporating ecologically relevant habitat and demographic data in assessment of contaminant risk to wildlife

    EPA Science Inventory

    Evaluating population-level effects of contamination on wildlife requires specific information on habitat quality, species distribution, and contaminant concentration. Establishing broadly applicable thresholds for risk assessment involves an understanding of the applicability o...

  19. Documenting the Effectiveness of Cosorption of Airborne Contaminants by a Field-Installed Active Desiccant System: Final Report - Phase 2D

    SciTech Connect

    Fischer, J

    2003-01-23

    The final report for Phase 1 of this research effort (ORNL/SUB/94-SV004/1) concluded that a significant market opportunity would exist for active desiccant systems if it could be demonstrated that they can remove a significant proportion of common airborne contaminants while simultaneously performing the primary function of dehumidifying a stream of outdoor air or recirculated building air. If the engineering community begins to follow the intent of ASHRAE Standard 62, now part of all major building codes, the outdoor air in many major cities may need to be pre-cleaned before it is introduced into occupied spaces. Common air contaminant cosorption capability would provide a solution to three important aspects of the ASHRAE 62-89 standard that have yet to be effectively addressed by heating, ventilation, and air-conditioning (HVAC) equipment manufacturers: (1) The ASHRAE standard defines acceptable outdoor air quality. If the outdoor air contains unacceptable levels of certain common outdoor air contaminants (e.g., sulfur dioxide, ozone), then the standard requires that these contaminants be removed from the outdoor air stream to reach compliance with the acceptable outdoor air quality guidelines. (2) Some engineers prefer to apply a filtration or prescriptive approach rather than a ventilation approach to solving indoor air quality problems. The ASHRAE standard recognizes this approach provided that the filtration technology exists to remove the gaseous contaminants encountered. The performance of current gaseous filtration technologies is not well documented, and they can be costly to maintain because the life of the filter is limited and the cost is high. Moreover, it is not easy to determine when the filters need changing. In such applications, an additional advantage provided by the active desiccant system would be that the same piece of equipment could control space humidity and provide filtration, even during unoccupied periods, if the active desiccant system

  20. Assessing canopy PRI from airborne imagery to map water stress in maize

    NASA Astrophysics Data System (ADS)

    Rossini, M.; Fava, F.; Cogliati, S.; Meroni, M.; Marchesi, A.; Panigada, C.; Giardino, C.; Busetto, L.; Migliavacca, M.; Amaducci, S.; Colombo, R.

    2013-12-01

    This paper presents a method for mapping water stress in a maize field using hyperspectral remote sensing imagery. An airborne survey using AISA (Specim, Finland) was performed in July 2008 over an experimental farm in Italy. Hyperspectral data were acquired over a maize field with three different irrigation regimes. An intensive field campaign was also conducted concurrently with imagery acquisition to measure relative leaf water content (RWC), active chlorophyll fluorescence (ΔF/Fm‧), leaf temperature (Tl) and Leaf Area Index (LAI). The analysis of the field data showed that at the time of the airborne overpass the maize plots with irrigation deficits were experiencing a moderate water stress, affecting the plant physiological status (ΔF/Fm‧, difference between Tl and air temperature (Tair), and RWC) but not the canopy structure (LAI). Among the different Vegetation Indices (VIs) computed from the airborne imagery the Photochemical Reflectance Index computed using the reflectance at 570 nm as the reference band (PRI570) showed the strongest relationships with ΔF/Fm‧ (r2 = 0.76), Tl - Tair (r2 = 0.82) and RWC (r2 = 0.64) and the red-edge Chlorophyll Index (CIred-edge) with LAI (r2 = 0.64). Thus PRI has been proven to be related to water stress at early stages, before structural changes occurred.

  1. Thermal Catalytic Oxidation of Airborne Contaminants by a Reactor Using Ultra-Short Channel Length, Monolithic Catalyst Substrates

    NASA Technical Reports Server (NTRS)

    Perry, J. L.; Tomes, K. M.; Tatara, J. D.

    2005-01-01

    Contaminated air, whether in a crewed spacecraft cabin or terrestrial work and living spaces, is a pervasive problem affecting human health, performance, and well being. The need for highly effective, economical air quality processes spans a wide range of terrestrial and space flight applications. Typically, air quality control processes rely on absorption-based processes. Most industrial packed-bed adsorption processes use activated carbon. Once saturated, the carbon is either dumped or regenerated. In either case, the dumped carbon and concentrated waste streams constitute a hazardous waste that must be handled safely while minimizing environmental impact. Thermal catalytic oxidation processes designed to address waste handling issues are moving to the forefront of cleaner air quality control and process gas decontamination processes. Careful consideration in designing the catalyst substrate and reactor can lead to more complete contaminant destruction and poisoning resistance. Maintenance improvements leading to reduced waste handling and process downtime can also be realized. Performance of a prototype thermal catalytic reaction based on ultra-short waste channel, monolith catalyst substrate design, under a variety of process flow and contaminant loading conditions, is discussed.

  2. Remote sensing and airborne geophysics in the assessment of natural aggregate resources

    USGS Publications Warehouse

    Knepper, D.H.; Langer, W.H.; Miller, S.H.

    1994-01-01

    Natural aggregate made from crushed stone and deposits of sand and gravel is a vital element of the construction industry in the United States. Although natural aggregate is a high volume/low value commodity that is relatively abundant, new sources of aggregate are becoming increasingly difficult to find and develop because of rigid industry specifications, political considerations, development and transporation costs, and environmental concerns, especially in urban growth centers where much of the aggregate is used. As the demand for natural aggregate increases in response to urban growth and the repair and expansion of the national infrastructure, new sources of natural aggregate will be required. The USGS has recognized the necessity of developing the capability to assess the potential for natural aggregate sources on Federal lands; at present, no methodology exists for systematically describing and evaluating potential sources of natural aggregate. Because remote sensing and airborne geophysics can detect surface and nearsurface phenomena, these tools may useful for detecting and mapping potential sources of natural aggregate; however, before a methodology for applying these tools can be developed, it is necessary to understand the type, distribution, physical properties, and characteristics of natural aggregate deposits, as well as the problems that will be encountered in assessing their potential value. There are two primary sources of natural aggregate: (1) exposed or near-surface igneous, metamorphic, and sedimentary bedrock that can be crushed, and (2) deposits of sand and gravel that may be used directly or crushed and sized to meet specifications. In any particular area, the availability of bedrock suitable for crushing is a function of the geologic history of the area - the processes that formed, deformed, eroded and exposed the bedrock. Deposits of sand and gravel are primarily surficial deposits formed by the erosion, transportation by water and ice

  3. Assessment of basic contamination withstand voltage characteristics of polymer insulators

    SciTech Connect

    Matsuoka, R.; Shinokubo, H.; Kondo, K.; Mizuno, Y.; Naito, K.; Fujimura, T.; Terada, T.

    1996-10-01

    An artificial contamination method for hydrophobic polymer insulators was newly developed, which can provide a uniform contaminant layer similar to the natural one neither by damaging the polymer surface nor by adding any chemical agent to the conventional contamination slurry. Using this method, basic contamination withstand voltage characteristics of polymer insulators were investigated comparing with those of porcelain insulators. The results show that although hydrophobic withstand voltage characteristics critical reduction of withstand voltage occurs sometimes under rapid and heavy wetting and contamination conditions.

  4. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  5. Real-time monitoring of non-viable airborne particles correlates with airborne colonies and represents an acceptable surrogate for daily assessment of cell-processing cleanroom performance

    PubMed Central

    RAVAL, JAY S.; KOCH, EILEEN; DONNENBERG, ALBERT D.

    2014-01-01

    Background aims Airborne particulate monitoring is mandated as a component of good manufacturing practice. We present a procedure developed to monitor and interpret airborne particulates in an International Organization for Standardization (ISO) class 7 cleanroom used for the cell processing of Section 351 and Section 361 products. Methods We collected paired viable and non-viable airborne particle data over a period of 1 year in locations chosen to provide a range of air quality. We used receiver operator characteristic (ROC) analysis to determine empirically the relationship between non-viable and viable airborne particle counts. Results Viable and non-viable particles were well-correlated (r 2 = 0.78), with outlier observations at the low end of the scale (non-viable particles without detectable airborne colonies). ROC analysis predicted viable counts ≥0.5/feet 3 (a limit set by the United States Pharmacopeia) at an action limit of ≥32 000 particles (≥0.5 μ)/feet 3 , with 95.6% sensitivity and 50% specificity. This limit was exceeded 2.6 times during 18 months of retrospective daily cleanroom data (an expected false alarm rate of 1.3 times/year). After implementing this action limit, we were alerted in real time to an air-handling failure undetected by our hospital facilities management. Conclusions A rational action limit for non-viable particles was determined based on the correlation with airborne colonies. Reaching or exceeding the action limit of 32 000 non-viable particles/feet 3 triggers suspension of cleanroom cell-processing activities, deep cleaning, investigation of air handling, and a deviation management process. Our full procedure for particle monitoring is available as an online supplement. PMID:22746538

  6. Chemometric assessment of enhanced bioremediation of oil contaminated soils.

    PubMed

    Soleimani, Mohsen; Farhoudi, Majid; Christensen, Jan H

    2013-06-15

    Bioremediation is a promising technique for reclamation of oil polluted soils. In this study, six methods for enhancing bioremediation were tested on oil contaminated soils from three refinery areas in Iran (Isfahan, Arak, and Tehran). The methods included bacterial enrichment, planting, and addition of nitrogen and phosphorous, molasses, hydrogen peroxide, and a surfactant (Tween 80). Total petroleum hydrocarbon (TPH) concentrations and CHEMometric analysis of Selected Ion Chromatograms (SIC) termed CHEMSIC method of petroleum biomarkers including terpanes, regular, diaromatic and triaromatic steranes were used for determining the level and type of hydrocarbon contamination. The same methods were used to study oil weathering of 2 to 6 ring polycyclic aromatic compounds (PACs). Results demonstrated that bacterial enrichment and addition of nutrients were most efficient with 50% to 62% removal of TPH. Furthermore, the CHEMSIC results demonstrated that the bacterial enrichment was more efficient in degradation of n-alkanes and low molecular weight PACs as well as alkylated PACs (e.g. C₃-C₄ naphthalenes, C₂ phenanthrenes and C₂-C₃ dibenzothiophenes), while nutrient addition led to a larger relative removal of isoprenoids (e.g. norpristane, pristane and phytane). It is concluded that the CHEMSIC method is a valuable tool for assessing bioremediation efficiency.

  7. Fungal contamination assessment in Portuguese elderly care centers.

    PubMed

    Viegas, C; Almeida-Silva, M; Gomes, A Quintal; Wolterbeek, H T; Almeida, S M

    2014-01-01

    Individuals spend 80-90% of their day indoors and elderly subjects are likely to spend even a greater amount of time indoors. Thus, indoor air pollutants such as bioaerosols may exert a significant impact on this age group. The aim of this study was to characterize fungal contamination within Portuguese elderly care centers. Fungi were measured using conventional as well as molecular methods in bedrooms, living rooms, canteens, storage areas, and outdoors. Bioaerosols were evaluated before and after the microenvironments' occupancy in order to understand the role played by occupancy in fungal contamination. Fungal load results varied from 32 colony-forming units CFU m(-3) in bedrooms to 228 CFU m(-3) in storage areas. Penicillium sp. was the most frequently isolated (38.1%), followed by Aspergillus sp. (16.3%) and Chrysonilia sp. (4.2%). With respect to Aspergillus genus, three different fungal species in indoor air were detected, with A. candidus (62.5%) the most prevalent. On surfaces, 40 different fungal species were isolated and the most frequent was Penicillium sp. (22.2%), followed by Aspergillus sp. (17.3%). Real-time polymerase chain reaction did not detect the presence of A. fumigatus complex. Species from Penicillium and Aspergillus genera were the most abundant in air and surfaces. The species A. fumigatus was present in 12.5% of all indoor microenvironments assessed. The living room was the indoor microenvironment with lowest fungal concentration and the storage area was highest.

  8. Assessing soil and groundwater contamination from biofuel spills.

    PubMed

    Chen, Colin S; Shu, Youn-Yuen; Wu, Suh-Huey; Tien, Chien-Jung

    2015-03-01

    Future modifications of fuels should include evaluation of the proposed constituents for their potential to damage environmental resources such as the subsurface environment. Batch and column experiments were designed to simulate biofuel spills in the subsurface environment and to evaluate the sorption and desorption behavior of target fuel constituents (i.e., monoaromatic and polyaromatic hydrocarbons) in soil. The extent and reversibility of the sorption of aromatic biofuel constituents onto soil were determined. When the ethanol content in ethanol-blended gasoline exceeded 25%, enhanced desorption of the aromatic constituents to water was observed. However, when biodiesel was added to diesel fuel, the sorption of target compounds was not affected. In addition, when the organic carbon content of the soil was higher, the desorption of target compounds into water was lower. The empirical relationships between the organic-carbon normalized sorption coefficient (Koc) and water solubility and between Koc and the octanol-water partition coefficient (Kow) were established. Column experiments were carried out for the comparison of column effluent concentration/mass from biofuel-contaminated soil. The dissolution of target components depended on chemical properties such as the hydrophobicity and total mass of biofuel. This study provides a basis for predicting the fate and transport of hydrophobic organic compounds in the event of a biofuel spill. The spill scenarios generated can assist in the assessment of biofuel-contaminated sites.

  9. Indirect methods of dried sewage sludge contamination assessments.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz; Grübel, Klaudiusz

    2016-07-28

    Thermal conversion (combustion, co-combustion, gasification and pyrolysis) appears to be the most promising alternative for sewage sludge management in the future. Nevertheless, safe and ecological usage of sewage sludge as a fuel requires information about their contamination. The aim of this paper is to present the photoacoustic spectroscopy (PAS) as a good method for contamination assessments of dried sewage sludge. Two types of granular sewage sludge: Sewage sludge 1 (SS1) taken from Polish wastewater treatment plant operating in the mechanical-biological system and sewage sludge 2 (SS2) taken from mechanical-biological-chemical wastewater treatment plant with phosphorus precipitation were analysed. The spectrophotometer FTIR Nicolet 6700 equipped with photoacoustic cell (Model 300, MTEC, USA) was used. The comparison with the most popular analytical methods (GC-MS) was also done. The results of PAS studies confirm the difference between the SS1 and SS2 which is in agreement with the GC-MS analysis. Higher absorbance was observed at each wavelength characteristics for the oscillator of chemical moieties for the SS1 with respect to the SS2. PMID:27149560

  10. ISSUES IN ASSESSING LOW LEVEL IONIZABLE CONTAMINANT PARTITIONING IN SOILS AND SEDIMENTS

    EPA Science Inventory

    Solubilization has profound implications for such diverse risk assessment activities as assessing sediment contaminant porewater exposures to benthic fauna, determining half lives of refractory toxicants in natural soils and sediments, and assessing the fate and transport of th...

  11. Critical examination of assumptions used in risk assessments of dioxin contaminated soil

    SciTech Connect

    Paustenbach, D.J.; Shu, H.P.; Murray, F.J.

    1986-09-01

    This paper critically evaluates several aspects of previously proposed approaches to setting limits for 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin, TCDD) in residential soil and soil within industrial sites. Factors and assumptions which significantly affect the predicted degree of hazard associated with exposure to soil contaminated with low levels of dioxin are discussed. This paper shows how different, more justifiable assumptions than those used by the Centers for Disease Control (CDC) regarding the quantities of soil typically consumed by children, TCDD's nongenotoxicity, dermal exposure to soil, the concentration of airborne soil particles, dioxin's bioavailability in soil, and extrapolation of the dose response curve can profoundly affect the results of the risk assessment and, subsequently, the magnitude of the recommended limits. Two case studies which quantitatively illustrate the effect of these assumptions on the risk estimates are presented. Non-U.S. regulatory agencies have considered TCDD's nongenotoxicity in estimating that the virtually safe dose (VSD) or acceptable daily dose for dioxin is approximately 10 pg/kg/day (10,000 fg/kg/day). These approaches are compared and contrasted with the method used by the United States EPA whose risk estimates are higher and whose VSD is approximately 1000-fold lower. Alternative approaches to interpreting the cancer data indicate that a VSD of 130 pg/kg/day is more scientifically justified than risks estimated using standard approaches. This assessment indicates that a soil concentration of TCDD considerably in excess of 1 ppb should be acceptable for residential and nonresidential areas.

  12. Alpha contamination assessment for D&D activities: Technology overview

    SciTech Connect

    Conaway, J.G.; Rawool-Sullivan, M.W.; MacArthur, D.W.

    1996-02-01

    Instruments based on the principle of Long-Range Alpha Detection (LRAD) detect the ions created in ambient air by Ionizing radiation, particularly alpha radiation, interacting with air molecules. Using either an electrostatic field or forced convection, these ions can be transported to a detection grid where the ions produce a small current that is measured with a sensitive electrometer. LRAD-based instruments can give separate, simultaneous measurements of alpha-emitting solids and inert radioactive gases such as radon. LRAD-based instruments assess surface contamination on an entire object or large surface area in a single, rapid measurement, including relatively inaccessible areas such as interior surfaces of pipes and process equipment. The LRAD concept is well proven and has been developed into a range of different radiation detection devices. This paper presents an overview of the technology, while several associated papers explore specific applications in greater detail.

  13. Clostridium difficile in a children's hospital: assessment of environmental contamination.

    PubMed

    Warrack, Simone; Duster, Megan; Van Hoof, Sarah; Schmitz, Michelle; Safdar, Nasia

    2014-07-01

    Clostridium difficile infection (CDI) is the most frequent infectious cause of health care-associated diarrhea. Three cases of CDI, in children age 2, 3, and 14 years, occurred in the hematology/oncology ward of our children's hospital over 48 hours. We aimed to assess environmental contamination with C difficile in the shared areas of this unit, and to determine whether person-to-person transmission occurred. C difficile was recovered from 5 of 18 samples (28%). We compared C difficile isolated from each patient and the environment using pulsed-field gel electrophoresis, and found that none of the patient strains matched any of the others, and that none matched any strains recovered from the environment, suggesting that person-to-person transmission had not occurred. We found that C difficile was prevalent in the environment throughout shared areas of the children's hospital unit. Molecular typing to identify mechanisms of transmission is useful for devising appropriate interventions.

  14. Assessing Ground-Water Contamination Across Broad Regions

    NASA Astrophysics Data System (ADS)

    Helsel, D. R.

    2001-05-01

    Ground-water quality is measured at discrete locations, and often interpreted at local scales. However, regional patterns in ground-water quality can be used to: 1) Assess relations between water quality and broad patterns of human activities or geochemical variation; 2) Reduce monitoring costs by sampling more frequently in areas of highest concentration or vulnerability; 3) Prioritize locations for prevention efforts such as for nitrate reduction, to obtain maximum benefits for lower costs; and 4) Project water-quality conditions to unsampled locations based on a regional understanding or "model". Examples of methods for modeling and interpreting ground-water quality at regional scales are presented along with their utility for cost reduction and contamination prevention purposes.

  15. Assessment of natural background levels in potentially contaminated coastal aquifers.

    PubMed

    Molinari, A; Chidichimo, F; Straface, S; Guadagnini, A

    2014-04-01

    The estimation of natural background levels (NBLs) of dissolved concentrations of target chemical species in subsurface reservoirs relies on a proper assessment of the effects of forcing terms driving flow and transport processes taking place within the system and whose dynamics drive background concentration values. We propose coupling methodologies based on (a) global statistical analyses and (b) numerical modeling of system dynamics to distinguish between the impacts of different types of external forcing components influencing background concentration values. We focus on the joint application of a statistical methodology based on Component Separation and experimental/numerical modeling studies of groundwater flow and transport for the NBL estimation of selected chemical species in potentially contaminated coastal aquifers. We consider a site which is located in Calabria, Italy, and constitutes a typical example of a Mediterranean coastal aquifer which has been subject to intense industrial development. Our study is keyed to the characterization of NBLs of manganese and sulfate and is geared to the proper identification of the importance of a natural external forcing (i.e., seawater intrusion) on NBL assessment. Results from the Component Separation statistical approach are complemented by numerical simulations of the advective-dispersive processes that could influence the distribution of chemical species (i.e., sulfate) within the system. Estimated NBLs for manganese are consistent with the geochemical composition of soil samples. While Component Separation ascribes the largest detected sulfate concentrations to anthropogenic sources, our numerical modeling analysis suggests that they are mainly related to the natural process of seawater intrusion. Our results indicate that the use of statistical methodologies in complex groundwater systems should be assisted by a detailed characterization of the dynamics of natural (and/or induced) processes to distinguish

  16. Establishment of Airborne Nanoparticle Exposure Chamber System to Assess Nano TiO2 Induced Mice Lung Effects

    NASA Astrophysics Data System (ADS)

    Chen, Chia-Hua; Li, Jui-Ping; Huang, Nai-Chun; Yang, Chung-Shi; Chen, Jen-Kun

    2011-12-01

    A great many governments have schemed their top priority to support the research and development of emerging nanotechnology, which lead to increasing products containing nanomaterials. However, platforms and protocols to evaluate the safety of nanomaterials are not yet established. We therefore design and fabricate a nanoparticle exposure chamber system (NECS) and try to standardize protocols to assess potential health risk of inhalable nanoparticles. This platform comprises: (1) nano-aerosol generators to produce homogeneous airborne nanoparticles, (2) double isolated container to prevent from unexpected exposure to humans, (3) gas supply system for housing animals or incubating cultured cells, and (4) system for automatic control and airborne nanoparticle analysis. The NECS providing multiple functions includes: (1) a secure environment to handle nanomaterials, (2) real-time measurement for the size and distribution of airborne nanoparticles, (3) SOP of safety evaluation for nanomaterials, and (4) key technology for the development of inhalable pharmaceuticals. We used NECS to mimic occupational environment for exploring potential adverse effects of TiO2 nanoparticles. The adult male ICR mice were exposed to 25nm, well-characterized TiO2 particles for 1 and 4 weeks. More than 90% of the inhaled TiO2 nanoparticles deposit in lung tissue, which tends to be captured by alveolar macrophages. Pulmonary function test does not show significant physiological changes between one and 4 weeks exposure. For plasma biochemistry analysis, there are no obvious inflammation responses after exposure for one and 4 weeks; however, disruption of alveolar septa and increased thickness of alveolar epithelial cells were observed. According to our results, the NECS together with our protocols show comprehensive integration and ideally fit the standard of OECD guildelines-TG403, TG412, TG413; it can be further customized to fulfill diverse demands of industry, government, and third party

  17. Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles

    PubMed Central

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L.

    2016-01-01

    Abstract The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm–2) at cell‐free conditions following 2 h exposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm–2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:26935862

  18. Health-related monitoring and assessment of airborne particulate matter. An overview of recent IAEA programs.

    PubMed

    Parr, R M; Smodis, B

    1999-01-01

    Since 1992, the International Atomic Energy Agency (IAEA) has been promoting studies of air pollution using a standard design of air sampler that provides separation on filters into two size fractions with cutoffs of 2.5 and 10 microns (approximately). These are the size ranges presently considered to have the most important health consequences. Such filter samples are highly amenable to analysis using nuclear and related techniques. After reviewing some of the health effects of airborne particulate matter and current air quality standards and guidelines, this article provides an overview of current and recent IAEA programs in this area, which involve collaborative activities with participants in more than 40 countries.

  19. A Performance Assessment of a Tactical Airborne Separation Assistance System using Realistic, Complex Traffic Flows

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Neitzke, Kurt W.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of aspects of an Airborne Separation Assistance System (ASAS) under varying demand levels using realistic traffic patterns. This study only addresses the tactical aspects of an ASAS using aircraft state data (latitude, longitude, altitude, heading and speed) to detect and resolve projected conflicts. The main focus of this paper is to determine the extent to which sole reliance on the proposed tactical ASAS can maintain aircraft separation at demand levels up to three times current traffic. The effect of mixing ASAS equipped aircraft with non-equipped aircraft that do not have the capability to self-separate is also investigated.

  20. PBT assessment and prioritization of contaminants of emerging concern: Pharmaceuticals.

    PubMed

    Sangion, Alessandro; Gramatica, Paola

    2016-05-01

    The strong and widespread use of pharmaceuticals, together with incorrect disposal procedures, has recently made these products contaminants of emerging concern (CEC). Unfortunately, little is known about pharmaceuticals' environmental behaviour and ecotoxicity, so that EMEA (European Medicines Agency) released guidelines for the pharmaceuticals' environmental risk assessment. In particular, there is a severe lack of information about persistence, bioaccumulation and toxicity (PBT) of the majority of the thousands of substances on the market. Computational tools, like QSAR (Quantitative Structure Activity Relationship) models, are the only way to screen large sets of chemicals in short time, with the aim of ranking, highlighting and prioritizing the most environmentally hazardous for focusing further experimental studies. In this work we propose a screening method to assess the potential persistence, bioaccumulation and toxicity of more than 1200 pharmaceutical ingredients, based on the application of two different QSAR models. We applied the Insubria-PBT Index, a MLR (Multiple Linear Regression) QSAR model based on four simple molecular descriptors, implemented in QSARINS software, and able to synthesize the PBT potential in a unique cumulative value and the US-EPA PBT Profiler that assesses the PBT behaviour evaluating separately P, B and T. Particular attention was given to the study of Applicability Domain in order to provide reliable predictions. An agreement of 86% was found between the two models and a priority list of 35 pharmaceuticals, highlighted as potential PBTs by consensus, was proposed for further experimental validation. Moreover, the results of this computational screening are in agreement with preliminary experimental data in the literature. This study shows how in silico models can be applied in the hazard assessment to perform preliminary screening and prioritization of chemicals, and how the identification of the structural features, mainly

  1. PBT assessment and prioritization of contaminants of emerging concern: Pharmaceuticals.

    PubMed

    Sangion, Alessandro; Gramatica, Paola

    2016-05-01

    The strong and widespread use of pharmaceuticals, together with incorrect disposal procedures, has recently made these products contaminants of emerging concern (CEC). Unfortunately, little is known about pharmaceuticals' environmental behaviour and ecotoxicity, so that EMEA (European Medicines Agency) released guidelines for the pharmaceuticals' environmental risk assessment. In particular, there is a severe lack of information about persistence, bioaccumulation and toxicity (PBT) of the majority of the thousands of substances on the market. Computational tools, like QSAR (Quantitative Structure Activity Relationship) models, are the only way to screen large sets of chemicals in short time, with the aim of ranking, highlighting and prioritizing the most environmentally hazardous for focusing further experimental studies. In this work we propose a screening method to assess the potential persistence, bioaccumulation and toxicity of more than 1200 pharmaceutical ingredients, based on the application of two different QSAR models. We applied the Insubria-PBT Index, a MLR (Multiple Linear Regression) QSAR model based on four simple molecular descriptors, implemented in QSARINS software, and able to synthesize the PBT potential in a unique cumulative value and the US-EPA PBT Profiler that assesses the PBT behaviour evaluating separately P, B and T. Particular attention was given to the study of Applicability Domain in order to provide reliable predictions. An agreement of 86% was found between the two models and a priority list of 35 pharmaceuticals, highlighted as potential PBTs by consensus, was proposed for further experimental validation. Moreover, the results of this computational screening are in agreement with preliminary experimental data in the literature. This study shows how in silico models can be applied in the hazard assessment to perform preliminary screening and prioritization of chemicals, and how the identification of the structural features, mainly

  2. Review of methods for assessing nonpoint-source contaminated ground-water discharge to surface water

    SciTech Connect

    Not Available

    1991-04-01

    The document provides an overview of selected methods that have been used for assessing nonpoint source contaminated ground water discharge to surface water. EPA undertook the project in response to the growing awareness that contaminated ground water discharge is a significant source of nonpoint source contaminant loading to surface water in many parts of the country.

  3. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    PubMed

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure. PMID:26233734

  4. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    PubMed

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure.

  5. Risk assessment of exposure to waterborne and airborne radon-222 in Illinois. Final report

    SciTech Connect

    Hallenbeck, W.H.

    1987-12-01

    This study analyzed epidemiological and experimental animal studies in order to develop exposure-response relationships for radon-induced cancer. These relationships were used to estimate lifetime risks and annual excess cases based on the available waterborne and airborne data for Illinois. Exceedances of the USEPA action level of 4pCi/l occurred in 13% of 303 first-floor measurements and 43% of 1094 basement measurements. For waterborne radon, the highest lifetime risk of cancer mortality associated with an Illinois groundwater-based drinking water system was estimated to be 4 x 104. The number of excess cases of fatal cancer generated per year in Illinois was estimated to be about six. For airborne radon, a tentative value of 0.9 pCi/l (for first floors), derived from the limited existing data, was used to estimate the average lifetime lung-cancer mortality risk and the number of excess cases of fatal lung cancer generated per year. The average lifetime lung-cancer mortality risk was estimated to be 0.0048, and the annual number of excess cases of fatal lung cancer was estimated to be 784. Due to the nature of the underlying exposure-response relationships for radon-induced cancer, the values presented most likely represent upper-bound estimates.

  6. Ecotoxicological and analytical assessment of hydrocarbon-contaminated soils and application to ecological risk assessment

    SciTech Connect

    Saterbak, A.; Toy, R.J.; Wong, D.C.L.; McMain, B.J.; Williams, M.P.; Dorn, P.B.; Brzuzy, L.P.; Chai, E.Y.; Salanitro, J.P.

    1999-07-01

    Ecotoxicological assessments of contaminated soil aim to understand the effect of introduced chemicals on the soil flora and fauna. Ecotoxicity test methods were developed and conducted on hydrocarbon-contaminated soils and on adjacent uncontaminated control soils from eight field locations. Tests included 7-d, 14-d, and chronic survival tests and reproduction assays for the earthworm (Eisenia fetida) and seed germination, root length, and plant growth assays for corn, lettuce, mustard, and wheat. Species-specific responses were observed with no-observed effect concentrations (NOECs) ranging from <1 to 100% contaminated soil. The 14-d earthworm survival NOEC was equal to or greater than the reproduction NOEC values for numbers of cocoons and juveniles, which were similar to one another. Cocoon and juvenile production varied among the control soils. Germination and root length NOECs for mustard and lettuce were less than NOECs for corn and wheat. Root length NOECs were similar to or less than seed germination NOECs. Statistically significant correlations for earthworm survival and seed germination as a function of hydrocarbon measurements were found. The 14-d earthworm survival and the seed germination tests are recommended for use in the context of a risk-based framework for the ecological assessment of contaminated sites.

  7. Airborne EM survey in volcanoes : Application to a volcanic hazards assessment

    NASA Astrophysics Data System (ADS)

    Mogi, T.

    2010-12-01

    Airborne electromagnetics (AEM) is a useful tool for investigating subsurface structures of volcanoes because it can survey large areas involving inaccessible areas. Disadvantages include lower accuracy and limited depth of investigation. AEM has been widely used in mineral exploration in frontier areas, and have been applying to engineering and environmental fields, particularly in studies involving active volcanoes. AEM systems typically comprise a transmitter and a receiver on an aircraft or in a towed bird, and although effective for surveying large areas, their penetration depth is limited because the distance between the transmitter and receiver is small and higher-frequency signals are used. To explore deeper structures using AEM, a semi-airborne system called GRounded Electrical source Airborne Transient ElectroMagnetics (GREATEM) has been developed. The system uses a grounded-electrical-dipole as the transmitter and generates horizontal electric fields. The GREATEM technology, first proposed by Mogi et al. (1998), has recently been improved and used in practical surveys (Mogi et al., 2009). The GREATEM survey system was developed to increase the depth of investigation possible using AEM. The method was tested in some volcanoes at 2004-2005. Here I will talk about some results of typical AEM surveys and GREATEM surveys in some volcanoes in Japan to mitigate hazards associated with volcano eruption. Geologic hazards caused by volcanic eruptions can be mitigated by a combination of prediction, preparedness and land-use control. Risk management depends on the identification of hazard zones and forecasting of eruptions. Hazard zoning involves the mapping of deposits which have formed during particular phases of volcanic activity and their extrapolation to identify the area which would be likely to suffer a similar hazard at some future time. The mapping is usually performed by surface geological surveys of volcanic deposits. Resistivity mapping by AEM is useful

  8. Assessment of bacterial pathogens in fresh rainwater and airborne particulate matter using Real-Time PCR

    NASA Astrophysics Data System (ADS)

    Kaushik, Rajni; Balasubramanian, Rajasekhar

    2012-01-01

    Bacterial pathogens in airborne particulate matter (PM) and in rainwater (RW) were detected using a robust and sensitive Real-Time PCR method. Both RW and PM were collected simultaneously in the tropical atmosphere of Singapore, which were then subjected to analysis for the presence of selected bacterial pathogens and potential pathogen of health concern ( Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Aeromonas hydrophila). These pathogens were found to be prevalent in both PM and RW samples with E. coli being the most prevalent potential pathogen in both types of samples. The temporal distribution of these pathogens in PM and RW was found to be similar to each other. Using the proposed microbiological technique, the atmospheric deposition (dry and wet deposition) of bacterial pathogens to lakes and reservoirs can be studied in view of growing concerns about the outbreak of waterborne diseases.

  9. Assessment of Elemental Content in Airborne Particulate Matter in Bratislava Atmosphere using INAA and AAS

    SciTech Connect

    Meresova, J.; Florek, M.; Holy, K.; Sykora, I.; Frontasyeva, M. V.; Pavlov, S. S.

    2007-11-26

    The wide range concentration of elements including heavy metals, halogens and rare earths in airborne particulate matter were investigated. Sixteen samples were collected on filters in Meteorological station, Comenius University Bratislava (Slovak Republic) in different seasons. Using instrumental neutron activation analysis (INAA) the concentrations of 29 elements (Na, Al, Cl, K, Ca, Sc, Ti, V, Mn, Fe, Ga, As, Se, Br, Rb, In, Sb, I, Cs, Ba, La, Sm, Dy, Tm, W, Au, Hg, Th, U) were determined. The concentrations of other 6 elements (Cr, Ni, Cu, Zn, Cd, Pb) were measured by atomic absorption spectrometry (AAS). The obtained results allow us to better understand the dynamic processes in the atmosphere and to quantify the air pollution and its trends.

  10. Assessing sources of airborne mineral dust and other aerosols, in Iraq

    NASA Astrophysics Data System (ADS)

    Engelbrecht, Johann P.; Jayanty, R. K. M.

    2013-06-01

    Most airborne particulate matter in Iraq comes from mineral dust sources. This paper describes the statistics and modeling of chemical results, specifically those from Teflon® filter samples collected at Tikrit, Balad, Taji, Baghdad, Tallil and Al Asad, in Iraq, in 2006/2007. Methodologies applied to the analytical results include calculation of correlation coefficients, Principal Components Analysis (PCA), and Positive Matrix Factorization (PMF) modeling. PCA provided a measure of the covariance within the data set, thereby identifying likely point sources and events. These include airborne mineral dusts of silicate and carbonate minerals, gypsum and salts, as well as anthropogenic sources of metallic fumes, possibly from battery smelting operations, and emissions of leaded gasoline vehicles. Five individual PMF factors (source categories) were modeled, four of which being assigned to components of geological dust, and the fifth to gasoline vehicle emissions together with battery smelting operations. The four modeled geological components, dust-siliceous, dust-calcic, dust-gypsum, and evaporate occur in variable ratios for each site and size fraction (TSP, PM10, and PM2.5), and also vary by season. In general, Tikrit and Taji have the largest and Al Asad the smallest percentages of siliceous dust. In contrast, Al Asad has the largest proportion of gypsum, in part representing the gypsiferous soils in that region. Baghdad has the highest proportions of evaporite in both size fractions, ascribed to the highly salinized agricultural soils, following millennia of irrigation along the Tigris River valley. Although dust storms along the Tigris and Euphrates River valleys originate from distal sources, the mineralogy bears signatures of local soils and air pollutants.

  11. Assessment of composition and origin of airborne bacteria in the free troposphere over Japan

    NASA Astrophysics Data System (ADS)

    Maki, Teruya; Kakikawa, Makiko; Kobayashi, Fumihisa; Yamada, Maromu; Matsuki, Atsushi; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2013-08-01

    Long-range transport of airborne microorganisms through the free troposphere significantly impacts biological ecosystems, human life, and atmospheric processes in downwind areas. However, microbial communities in the free troposphere have rarely been investigated because the direct collection of microbial cells at high altitudes requires sophisticated sampling techniques. In this study, tropospheric air sampling was performed using a balloon and an aircraft at 800 m and 3000 m, respectively, over the Noto Peninsula in Japan (37.5°N, 137.4°E) where free tropospheric winds carry aerosols from continental areas. The air samples were collected during four different sampling periods when air masses came from desert regions of Asian continent (west samples) and from Siberia of Russia North Asia (north samples). The west samples contained higher levels of aerosols, and bacteria from the west samples grew in culture media containing up to 15% NaCl. In contrast, bacteria from the north samples could not be cultured in the same media. All isolates obtained from the NaCl-amended cultures were similar to Bacillus subtilis and classified as Firmicutes. A 16S rDNA clone library prepared from the west samples was mainly composed of one phylotype of Firmicutes that corresponded to the cultured B. subtilis sequence. A clone library prepared from the north samples consisted primarily of two phyla, i.e., Actinobacteria and Proteobacteria, which are known to dominantly inhabit low-temperature environments of North Asia. Our results suggest that airborne bacterial communities at high altitudes include several species that vary by the direction and interaction of free tropospheric winds.

  12. Toxicity Assessment of Contaminated Soils of Solid Domestic Waste Landfill

    NASA Astrophysics Data System (ADS)

    Pasko, O. A.; Mochalova, T. N.

    2014-08-01

    The paper delivers the analysis of an 18-year dynamic pattern of land pollutants concentration in the soils of a solid domestic waste landfill. It also presents the composition of the contaminated soils from different areas of the waste landfill during its operating period. The authors calculate the concentrations of the following pollutants: chrome, nickel, tin, vanadium, lead, cuprum, zinc, cobalt, beryllium, barium, yttrium, cadmium, arsenic, germanium, nitrate ions and petrochemicals and determine a consistent pattern of their spatial distribution within the waste landfill area as well as the dynamic pattern of their concentration. Test-objects are used in experiments to make an integral assessment of the polluted soil's impact on living organisms. It was discovered that the soil samples of an animal burial site are characterized by acute toxicity while the area of open waste dumping is the most dangerous in terms of a number of pollutants. This contradiction can be attributed to the synergetic effect of the polluted soil, which accounts for the regularities described by other researchers.

  13. Assessment of lead bioaccessibility in peri-urban contaminated soils.

    PubMed

    Smith, Euan; Weber, John; Naidu, Ravi; McLaren, Ronald G; Juhasz, Albert L

    2011-02-15

    Lead (Pb) bioaccessibility was assessed in a range of peri-urban soils (n=31) with differing sources of Pb contamination, including shooting range soils, and soils affected by incinerator, historical fill, mining/smelting, and gasworks activities. A gossan soil sample was also included. Lead bioaccessibility was determined using both gastric and intestinal phases of the SBRC in vitro assay and in vitro data was then incorporated into in vivo-in vitro regression equations to calculate Pb relative bioavailability. Lead bioaccessibility ranged from 26.8-105.2% to 5.5-102.6% for gastric and intestinal phase extractions respectively. Generally, Pb bioaccessibility was highest in the shooting range soils and lowest in the gossan soil. Predictions of relative Pb bioavailability derived from in vitro data were comparable for shooting ranges soils, but highly variable for the other soils examined. For incinerator, historical fill, gasworks and gossan soils, incorporating in vitro gastric data into the in vivo-in vitro regression equation resulting in more conservative Pb relative bioavailability values than those derived using the intestinal in vitro data. PMID:21115224

  14. Surface Water Contamination Risk Assessment Modeled by Fuzzy-WRASTIC.

    PubMed

    Alavipoor, Fatemeh Sadat; Ghorbaninia, Zahra; Karimi, Saeed; Jafari, Hamidreza

    2016-07-01

    This research provides a Fuzzy-WRASTIC new model for water resource contamination risk assessment in a GIS (Geographic Information System) environment. First, this method setting in a multi-criteria evaluation framework (MCE) reviewed and mapped the sub criteria of every above-mentioned criterion. Then, related sub-layers were phased by the observance of GIS environment standards. In the next step, first the sub-layers were combined together, next the modeling of pollution risk status was done by utilizing a fuzzy overlay method and applying the OR, AND, SUM, PRODUCT and GAMMA operators by using WLC (Weighted Linear Combination) method and providing weights in the WRASTIC model. The results provide the best combination of modeling and the percentages of its risk categories of low, medium, high and very high, which are respectively 1.8, 14.07, 51.43 and 32.7. More areas have severe risk due to the unbalanced arrangement and compact of land uses around the compact surface water resources. PMID:27329055

  15. Assessing OSL signal contamination with the composition test

    NASA Astrophysics Data System (ADS)

    Lawson, M. J.; Daniels, J. T.; Rhodes, E. J.

    2013-12-01

    Optically Stimulated Luminescence (OSL) has been applied towards the dating of many geomorphologic contexts and surface processes. The evolution of fluvial systems have been extensively studied using OSL (e.g. Rittenour, 2008), but has yet to overcome the limitations for quartz based OSL dating of fluvial sediments in active tectonic areas. Unfortunately, quartz in these regions is often characterized by weak OSL emissions and can suffer from signal contamination from small mineral inclusions. The OSL signal contributions from these inclusions may dominate the measured signal, given that feldspar often has an inherently brighter signal than quartz. Previously, we presented a signal composition test (Lawson et al., 2012) which utilizes thermal quenching and susceptibility to infrared bleaching to assess the contributions of quartz emissions to the total OSL signal. Additional measurements have been made, accessing how small volumes of feldspar can affect the results of aliquots tested with this composition test. Further, additional feldspar samples have been assessed for their response to the composition test, whose chemistry was determined using energy-dispersive X-ray (EDAX) spectroscopy. The test offers a new tool to determine the best strategy to access signal properties within varying dating contexts, delivering a way to access the best way to date sediments. Lawson, M., Roder, B., Stang, D., & Rhodes, E., 2012. OSL and IRSL characteristics of quartz and feldspar from southern California, USA. Radiation Measurements 47, 830-836. Rittenour, R.M, 2008. Luminescence dating of fluvial deposits: applications to geomorphic, paleoseismic and archaeological research. Boreas 37, 613-635.

  16. Reliability and validity of expert assessment based on airborne and urinary measures of nickel and chromium exposure in the electroplating industry

    PubMed Central

    Chen, Yu-Cheng; Coble, Joseph B; Deziel, Nicole C.; Ji, Bu-Tian; Xue, Shouzheng; Lu, Wei; Stewart, Patricia A; Friesen, Melissa C

    2014-01-01

    The reliability and validity of six experts’ exposure ratings were evaluated for 64 nickel-exposed and 72 chromium-exposed workers from six Shanghai electroplating plants based on airborne and urinary nickel and chromium measurements. Three industrial hygienists and three occupational physicians independently ranked the exposure intensity of each metal on an ordinal scale (1–4) for each worker's job in two rounds: the first round was based on responses to an occupational history questionnaire and the second round also included responses to an electroplating industry-specific questionnaire. Spearman correlation (rs) was used to compare each rating's validity to its corresponding subject-specific arithmetic mean of four airborne or four urinary measurements. Reliability was moderately-high (weighted kappa range=0.60–0.64). Validity was poor to moderate (rs= -0.37–0.46) for both airborne and urinary concentrations of both metals. For airborne nickel concentrations, validity differed by plant. For dichotomized metrics, sensitivity and specificity were higher based on urinary measurements (47–78%) than airborne measurements (16–50%). Few patterns were observed by metal, assessment round, or expert type. These results suggest that, for electroplating exposures, experts can achieve moderately-high agreement and (reasonably) distinguish between low and high exposures when reviewing responses to in-depth questionnaires used in population-based case-control studies. PMID:24736099

  17. Reliability and validity of expert assessment based on airborne and urinary measures of nickel and chromium exposure in the electroplating industry.

    PubMed

    Chen, Yu-Cheng; Coble, Joseph B; Deziel, Nicole C; Ji, Bu-Tian; Xue, Shouzheng; Lu, Wei; Stewart, Patricia A; Friesen, Melissa C

    2014-11-01

    The reliability and validity of six experts' exposure ratings were evaluated for 64 nickel-exposed and 72 chromium-exposed workers from six Shanghai electroplating plants based on airborne and urinary nickel and chromium measurements. Three industrial hygienists and three occupational physicians independently ranked the exposure intensity of each metal on an ordinal scale (1-4) for each worker's job in two rounds: the first round was based on responses to an occupational history questionnaire and the second round also included responses to an electroplating industry-specific questionnaire. The Spearman correlation (r(s)) was used to compare each rating's validity to its corresponding subject-specific arithmetic mean of four airborne or four urinary measurements. Reliability was moderately high (weighted kappa range=0.60-0.64). Validity was poor to moderate (r(s)=-0.37-0.46) for both airborne and urinary concentrations of both metals. For airborne nickel concentrations, validity differed by plant. For dichotomized metrics, sensitivity and specificity were higher based on urinary measurements (47-78%) than airborne measurements (16-50%). Few patterns were observed by metal, assessment round, or expert type. These results suggest that, for electroplating exposures, experts can achieve moderately high agreement and (reasonably) distinguish between low and high exposures when reviewing responses to in-depth questionnaires used in population-based case-control studies.

  18. Organic contaminants in direct coal liquefaction--a preliminary assessment.

    PubMed

    Tanita, R; Telesca, D; Walker, J; Berardinelli, S

    1980-11-01

    Area samples taken at two coal liquefaction facilities were analyzed by either gas chromatography or gas chromatography/mass spectrometry to identify the types of organic contaminants to which workers may be exposed. Results indicate that the contaminants consisted primarily of one or two ring low-molecular weight aromatic compounds.

  19. Assessing stream temperature variations in the Pacific Northwest using airborne thermal infrared remote sensing

    NASA Astrophysics Data System (ADS)

    Tan, J.; Cherkauer, K. A.

    2010-12-01

    Stream temperature is an important indicator of water quality, and a significant concern for endangered cold-water fish species in the Pacific Northwest. Thermal-infrared (TIR) remote sensing allows for the observation of water temperatures in entire river systems in a relatively short space of time, as opposed to more traditional point-based in situ observing methods that can capture only localized water conditions. Point measurements can therefore miss important spatial patterns associated with various factors including exposure to solar radiation, urbanization, changes to riparian zone vegetation, and the presence of groundwater returns and springs. In this paper, we analyze moderate resolution TIR imagery collected from an airborne platform for the Green River in Washington State. Five-meter MODIS/ASTER (MASTER) imagery along the main channel of the Green River was acquired in multiple straight line passes with image overlaps occurring at time intervals of between 3 and 30 minutes on August 25 and 27, 2001. Overlaps of two adjacent images provide a detailed comparison of how stream temperature changes over relatively short time scales, while image captured from different days help identify persistent localized temperature differences. Trees and shrubs in the riparian zone increases shading of the stream and reduces along-stream increases in temperature compared to stream reaches with reduced shading, such as urban areas. Longitudinal profiles of stream temperature from upstream to downstream show that other factors, such as sandbars and cold-water seeps, also contribute to along-stream temperature variations.

  20. Assessing and modeling moose (Alces alces) habitats with airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Melin, M.; Packalén, P.; Matala, J.; Mehtätalo, L.; Pusenius, J.

    2013-08-01

    In the analysis of forest resources, the use of ALS (airborne laser scanning) enables detailed three dimensional (3D) descriptions of forests and their vegetation. Simultaneously, ecologists have recognized that 3D information on vegetation is highly important in analyzing the habitat suitability of a given site. Recently, animals’ habitat preferences have been analyzed, for example, with GPS-collared animals. This has resulted in detailed knowledge about the animals’ movements both spatially and temporally. This study combines 3D information on vegetation obtained from ALS data with information about animal locations from GPS data. The aim was to map and analyze the habitat preferences of moose. The study area was located on the west coast of Finland. The data consisted of 18 GPS-collared moose (monitored from 2009 to 2010) and ALS data collected in 2010. We investigated how habitat structure changes as a function of distance to observed moose locations and how observed moose locations differ from randomly selected locations in terms of 3D structure. We also created a model-based habitat suitability map and tested it against moose occurrences. The results suggested that there are clear differences between the areas occupied and not occupied by moose and that these differences can be detected from ALS data. More importantly, ALS proved its potential in linking 3D descriptions of vegetation directly to observed moose locations without any proxy variables. These observations strongly support future studies.

  1. Radiometric stability assessment of an airborne photogrammetric sensor in a test field

    NASA Astrophysics Data System (ADS)

    Markelin, Lauri; Honkavaara, Eija; Hakala, Teemu; Suomalainen, Juha; Peltoniemi, Jouni

    Radiometric stability is a desired property of digital photogrammetric large-format sensors. This article presents a methodology for determining the radiometric stability of airborne imaging sensors in operational conditions in a test field and the results of stability evaluation of a large-format photogrammetric frame sensor DMC, from Intergraph. The imagery was collected in two days using nine different exposure settings, and images collected with variable exposure time and aperture were compared. The results showed promising stability in many cases, up to a level of 2% of the radiance, but less favorable results also appeared. Possible reasons for the unfavorable results could be the limitations of the experimental set-up or the instability of the sensor. DMC showed high radiometric performance potential, but high sensitivity to the exposure settings. Based on the results, recommendations for the future test field calibration and validation procedures were given. One limitation of the analysis was the insufficient information about the sensor stability potential; proposals were given to sensor manufacturers concerning the necessary information.

  2. Assessing visual green effects of individual urban trees using airborne Lidar data.

    PubMed

    Chen, Ziyue; Xu, Bing; Gao, Bingbo

    2015-12-01

    Urban trees benefit people's daily life in terms of air quality, local climate, recreation and aesthetics. Among these functions, a growing number of studies have been conducted to understand the relationship between residents' preference towards local environments and visual green effects of urban greenery. However, except for on-site photography, there are few quantitative methods to calculate green visibility, especially tree green visibility, from viewers' perspectives. To fill this research gap, a case study was conducted in the city of Cambridge, which has a diversity of tree species, sizes and shapes. Firstly, a photograph-based survey was conducted to approximate the actual value of visual green effects of individual urban trees. In addition, small footprint airborne Lidar (Light detection and ranging) data was employed to measure the size and shape of individual trees. Next, correlations between visual tree green effects and tree structural parameters were examined. Through experiments and gradual refinement, a regression model with satisfactory R2 and limited large errors is proposed. Considering the diversity of sample trees and the result of cross-validation, this model has the potential to be applied to other study sites. This research provides urban planners and decision makers with an innovative method to analyse and evaluate landscape patterns in terms of tree greenness.

  3. Final Report DE-EE0005380: Assessment of Offshore Wind Farm Effects on Sea Surface, Subsurface and Airborne Electronic Systems

    SciTech Connect

    Ling, Hao; Hamilton, Mark F.; Bhalla, Rajan; Brown, Walter E.; Hay, Todd A.; Whitelonis, Nicholas J.; Yang, Shang-Te; Naqvi, Aale R.

    2013-09-30

    Offshore wind energy is a valuable resource that can provide a significant boost to the US renewable energy portfolio. A current constraint to the development of offshore wind farms is the potential for interference to be caused by large wind farms on existing electronic and acoustical equipment such as radar and sonar systems for surveillance, navigation and communications. The US Department of Energy funded this study as an objective assessment of possible interference to various types of equipment operating in the marine environment where offshore wind farms could be installed. The objective of this project was to conduct a baseline evaluation of electromagnetic and acoustical challenges to sea surface, subsurface and airborne electronic systems presented by offshore wind farms. To accomplish this goal, the following tasks were carried out: (1) survey electronic systems that can potentially be impacted by large offshore wind farms, and identify impact assessment studies and research and development activities both within and outside the US, (2) engage key stakeholders to identify their possible concerns and operating requirements, (3) conduct first-principle modeling on the interactions of electromagnetic signals with, and the radiation of underwater acoustic signals from, offshore wind farms to evaluate the effect of such interactions on electronic systems, and (4) provide impact assessments, recommend mitigation methods, prioritize future research directions, and disseminate project findings. This report provides a detailed description of the methodologies used to carry out the study, key findings of the study, and a list of recommendations derived based the findings.

  4. Sustainable mineral resources management: from regional mineral resources exploration to spatial contamination risk assessment of mining

    NASA Astrophysics Data System (ADS)

    Jordan, Gyozo

    2009-07-01

    Wide-spread environmental contamination associated with historic mining in Europe has triggered social responses to improve related environmental legislation, the environmental assessment and management methods for the mining industry. Mining has some unique features such as natural background contamination associated with mineral deposits, industrial activities and contamination in the three-dimensional subsurface space, problem of long-term remediation after mine closure, problem of secondary contaminated areas around mine sites, land use conflicts and abandoned mines. These problems require special tools to address the complexity of the environmental problems of mining-related contamination. The objective of this paper is to show how regional mineral resources mapping has developed into the spatial contamination risk assessment of mining and how geological knowledge can be transferred to environmental assessment of mines. The paper provides a state-of-the-art review of the spatial mine inventory, hazard, impact and risk assessment and ranking methods developed by national and international efforts in Europe. It is concluded that geological knowledge on mineral resources exploration is essential and should be used for the environmental contamination assessment of mines. Also, sufficient methodological experience, knowledge and documented results are available, but harmonisation of these methods is still required for the efficient spatial environmental assessment of mine contamination.

  5. Health risk-based assessment and management of heavy metals-contaminated soil sites in Taiwan.

    PubMed

    Lai, Hung-Yu; Hseu, Zeng-Yei; Chen, Ting-Chien; Chen, Bo-Ching; Guo, Horng-Yuh; Chen, Zueng-Sang

    2010-10-01

    Risk-based assessment is a way to evaluate the potential hazards of contaminated sites and is based on considering linkages between pollution sources, pathways, and receptors. These linkages can be broken by source reduction, pathway management, and modifying exposure of the receptors. In Taiwan, the Soil and Groundwater Pollution Remediation Act (SGWPR Act) uses one target regulation to evaluate the contamination status of soil and groundwater pollution. More than 600 sites contaminated with heavy metals (HMs) have been remediated and the costs of this process are always high. Besides using soil remediation techniques to remove contaminants from these sites, the selection of possible remediation methods to obtain rapid risk reduction is permissible and of increasing interest. This paper discusses previous soil remediation techniques applied to different sites in Taiwan and also clarified the differences of risk assessment before and after soil remediation obtained by applying different risk assessment models. This paper also includes many case studies on: (1) food safety risk assessment for brown rice growing in a HMs-contaminated site; (2) a tiered approach to health risk assessment for a contaminated site; (3) risk assessment for phytoremediation techniques applied in HMs-contaminated sites; and (4) soil remediation cost analysis for contaminated sites in Taiwan.

  6. Ecosystem services - from assessements of estimations to quantitative, validated, high-resolution, continental-scale mapping via airborne LIDAR

    NASA Astrophysics Data System (ADS)

    Zlinszky, András; Pfeifer, Norbert

    2016-04-01

    "Ecosystem services" defined vaguely as "nature's benefits to people" are a trending concept in ecology and conservation. Quantifying and mapping these services is a longtime demand of both ecosystems science and environmental policy. The current state of the art is to use existing maps of land cover, and assign certain average ecosystem service values to their unit areas. This approach has some major weaknesses: the concept of "ecosystem services", the input land cover maps and the value indicators. Such assessments often aim at valueing services in terms of human currency as a basis for decision-making, although this approach remains contested. Land cover maps used for ecosystem service assessments (typically the CORINE land cover product) are generated from continental-scale satellite imagery, with resolution in the range of hundreds of meters. In some rare cases, airborne sensors are used, with higher resolution but less covered area. Typically, general land cover classes are used instead of categories defined specifically for the purpose of ecosystem service assessment. The value indicators are developed for and tested on small study sites, but widely applied and adapted to other sites far away (a process called benefit transfer) where local information may not be available. Upscaling is always problematic since such measurements investigate areas much smaller than the output map unit. Nevertheless, remote sensing is still expected to play a major role in conceptualization and assessment of ecosystem services. We propose that an improvement of several orders of magnitude in resolution and accuracy is possible through the application of airborne LIDAR, a measurement technique now routinely used for collection of countrywide three-dimensional datasets with typically sub-meter resolution. However, this requires a clear definition of the concept of ecosystem services and the variables in focus: remote sensing can measure variables closely related to "ecosystem

  7. A spatially-evaluated methodology for assessing risk to a population from contaminated land.

    PubMed

    Gay, J Rebecca; Korre, Anna

    2006-07-01

    A methodology is proposed which combines quantitative probabilistic human health risk assessment and spatial statistical methods (geostatistics) to produce an assessment of risks to human health from exposure to contaminated land, in a manner which preserves the spatial distribution of risks and provides a measure of uncertainty in the assessment. Maps of soil contaminant levels, which incorporate uncertainty, are produced from sparse sample data using sequential indicator simulation. A real, age-stratified population is mapped across the contaminated area, and intake of soil contaminants by individuals is calculated probabilistically using an adaptation of the Contaminated Land Exposure Assessment (CLEA) model. An abundance of information is contained in results which can be interrogated at the population and individual level, and mapped to provide a powerful visual tool for risk managers, enabling efficient targeting of risk reduction measures to different locations. PMID:16352380

  8. USING SPMDS TO ASSESS MANAGEMENT STRATEGIES FOR PCB CONTAMINATED SEDIMENTS.

    EPA Science Inventory

    Abstract: Dredging in-place treatment, capping and monitored natural recovery, used together or separately are the primary approaches for managing contaminated sediment risks. Understanding how well different approaches work in different environments is critical for choosing an...

  9. Field-based Metabolomics for Assessing Contaminated Surface Waters

    EPA Science Inventory

    Metabolomics is becoming well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical tox...

  10. Assessing Scale Effects on Snow Water Equivalent Retrievals Using Airborne and Spaceborne Passive Microwave Data

    NASA Astrophysics Data System (ADS)

    Derksen, C.; Walker, A.; Goodison, B.

    2003-12-01

    The Climate Research Branch (CRB) of the Meteorological Service of Canada (MSC) has a long-standing research program focused on the development of methods to retrieve snow cover information from passive microwave satellite data for Canadian regions. Algorithms that derive snow water equivalent (SWE) have been developed by CRB and are used to operationally generate SWE information over landscape regions including prairie, boreal forest, and taiga. New multi-scale research datasets were acquired in Saskatchewan, Canada during February 2003 to quantify the impact of spatially heterogeneous land cover and snowpack properties on passive microwave SWE retrievals. MSC microwave radiometers (6.9, 19, 37, and 85 GHz) were flown on the National Research Council (NRC) Twin Otter aircraft at two flying heights along a grid of flight lines, covering a 25 by 25 km study area centered on the Old Jack Pine Boreal Ecosystem Research and Monitoring Site (BERMS). Spaceborne Special Sensor Microwave/Imager (SSM/I) and Advanced Microwave Scanning Radiometer (AMSR-E) brightness temperatures were also acquired for this region. SWE was derived for all passive microwave datasets using the CRB land cover sensitive algorithm suite. An intensive, coincident ground sampling program characterized in situ snow depth, density, water equivalent and pack structure using a land cover based sampling scheme to isolate the variability in snow cover parameters within and between forest stands and land cover types, and within a single spaceborne passive microwave grid cell. The passive microwave data sets that are the focus of this investigation cover a range of spatial resolutions from 100-150 m for the airborne data to 10 km (AMSR-E) and 25 km (SSM/I) for the satellite data, providing the opportunity to investigate and compare microwave emission characteristics, SWE retrievals and land cover effects at different spatial scales. Initial analysis shows that the small footprint airborne passive microwave

  11. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Durango, Colorado

    SciTech Connect

    Not Available

    1995-02-01

    This risk assessment evaluates the possibility of health and environmental risks from contaminated ground water at the uranium mill tailings site near Durango, Colorado. The former uranium processing site`s contaminated soil and material were removed and placed at a disposal site located in Body Canyon, Colorado, during 1986--1991 by the US Departments of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating the nature and extent of ground water contamination at the site. This risk assessment follows an approach similar to that used by the US Environmental Protection Agency. The first step is to determine what site-related contaminants are found in ground water samples. The next step in the risk assessment is to determine how much of these contaminants people might ingest if they got their drinking water from a well on the site. In accordance with standard practice for this type of risk assessment, the highest contaminant concentrations from the most contaminated wells are used. The risk assessment then explains the possible health problems that could result from this amount of contamination.

  12. Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

    SciTech Connect

    Not Available

    1993-12-01

    This Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells. This risk assessment evaluates the most contaminated monitor wells at the processing site. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.

  13. Assessing stream temperature variation in the Pacific Northwest using airborne thermal infrared remote sensing.

    PubMed

    Tan, Jing; Cherkauer, Keith A

    2013-01-30

    The objective of this paper is to evaluate the temporal and spatial variability of stream temperatures and how stream temperatures are affected by land use through the use of airborne thermal infrared (TIR) imagery. Both five-meter and fifteen-meter MODIS/ASTER (MASTER) imagery were acquired along the main channel of the Green-Duwamish River in Washington State, U.S. in multiple straight line passes with image overlaps occurring at time intervals of between 3 and 45 min. Five- and fifteen-meter data were collected on August 25th, 2001, with a few additional five-meter images collected on August 27th. Image overlaps were studied to evaluate the time dependence between acquisition time and observed water temperature. Temperature change between adjacent images over the course of a few minutes was found to be negligible, but became significant at times greater than 45 min, with an estimated increase in water temperature of 2-3 °C between the first and last image collected for the complete five-meter resolution survey. Images captured from different days help identify persistent localized temperature differences. While accounting for temperature changes that occurred during the acquisition process, we still found that average stream reach temperatures increased with urbanization, while variability decreased. The same occurred in the immediate presence of a reservoir. This study suggests that urbanization affects stream temperature not only through the removal of riparian zone vegetation, but also through changes to sources in in-stream variability including the presence of rocks, woody debris and sandbars.

  14. Assessment of airborne heavy metal pollution using plant parts and topsoil.

    PubMed

    Serbula, Snezana M; Miljkovic, Dusanka Dj; Kovacevic, Renata M; Ilic, Ana A

    2012-02-01

    Robinia pseudoacacia L. (Fabaceae) was evaluated as a possible bioindicator of airborne heavy metal pollution, which originates from mining and pyrometallurgical copper production in Bor (Eastern Serbia). Concentrations of Cu, Zn, Pb, Cd, As and Hg were determined in different plant organs (washed/unwashed leaves, branches, roots) and topsoil of R. pseudoacacia by ICP-AES and by AAS. Sampling was carried out during 2008 at ten selected sites distributed in five zones with different levels of pollution. Concentrations of Pb, Cd and Hg did not exceeded the maximum allowed concentration (MAC) in soils at any of the sampling sites. Cu and As were present only at two sites within the MAC, whereas Zn exceeded the MAC at two sampling sites. Although present in the soil, As, Cd and Hg were below limit of detection in all parts of R. pseudoacacia. The rest of the studied elements, collected at the sites closest to the copper smelter or in the directions of the prevailing winds, were found to be at high levels. The higest Cu and Zn concentrations were detected in branches of R. pseudoacacia at the site Krivelj in the rural zone (6418.2±355.4 mg kg⁻¹ and 4699.8±320.8 mg kg⁻¹, respectively). Pb was present in similar amounts in all parts of R. pseudoacacia in the concentration ranging from 4.9 ± 0.3 mg kg⁻¹ (in washed leaves, at tourist zone) to 66.9±5.3 mg kg⁻¹ (in roots, at urban-industrial zone). According to the mobility ratio, leaves and branches of R. pseudoacacia acted as excluders of Cu, Zn and Pb, except for the branches which acted as indicators of Zn. Although As is present in high concentrations in the air and topsoil of the examined area, results show that R. pseudoacacia is not a suitable indicator of environmental pollution with As. PMID:22018546

  15. Assessing and Correcting Topographic Effects on Forest Canopy Height Retrieval Using Airborne LiDAR Data

    PubMed Central

    Duan, Zhugeng; Zhao, Dan; Zeng, Yuan; Zhao, Yujin; Wu, Bingfang; Zhu, Jianjun

    2015-01-01

    Topography affects forest canopy height retrieval based on airborne Light Detection and Ranging (LiDAR) data a lot. This paper proposes a method for correcting deviations caused by topography based on individual tree crown segmentation. The point cloud of an individual tree was extracted according to crown boundaries of isolated individual trees from digital orthophoto maps (DOMs). Normalized canopy height was calculated by subtracting the elevation of centres of gravity from the elevation of point cloud. First, individual tree crown boundaries are obtained by carrying out segmentation on the DOM. Second, point clouds of the individual trees are extracted based on the boundaries. Third, precise DEM is derived from the point cloud which is classified by a multi-scale curvature classification algorithm. Finally, a height weighted correction method is applied to correct the topological effects. The method is applied to LiDAR data acquired in South China, and its effectiveness is tested using 41 field survey plots. The results show that the terrain impacts the canopy height of individual trees in that the downslope side of the tree trunk is elevated and the upslope side is depressed. This further affects the extraction of the location and crown of individual trees. A strong correlation was detected between the slope gradient and the proportions of returns with height differences more than 0.3, 0.5 and 0.8 m in the total returns, with coefficient of determination R2 of 0.83, 0.76, and 0.60 (n = 41), respectively. PMID:26016907

  16. Assessing and correcting topographic effects on forest canopy height retrieval using airborne LiDAR data.

    PubMed

    Duan, Zhugeng; Zhao, Dan; Zeng, Yuan; Zhao, Yujin; Wu, Bingfang; Zhu, Jianjun

    2015-01-01

    Topography affects forest canopy height retrieval based on airborne Light Detection and Ranging (LiDAR) data a lot. This paper proposes a method for correcting deviations caused by topography based on individual tree crown segmentation. The point cloud of an individual tree was extracted according to crown boundaries of isolated individual trees from digital orthophoto maps (DOMs). Normalized canopy height was calculated by subtracting the elevation of centres of gravity from the elevation of point cloud. First, individual tree crown boundaries are obtained by carrying out segmentation on the DOM. Second, point clouds of the individual trees are extracted based on the boundaries. Third, precise DEM is derived from the point cloud which is classified by a multi-scale curvature classification algorithm. Finally, a height weighted correction method is applied to correct the topological effects. The method is applied to LiDAR data acquired in South China, and its effectiveness is tested using 41 field survey plots. The results show that the terrain impacts the canopy height of individual trees in that the downslope side of the tree trunk is elevated and the upslope side is depressed. This further affects the extraction of the location and crown of individual trees. A strong correlation was detected between the slope gradient and the proportions of returns with height differences more than 0.3, 0.5 and 0.8 m in the total returns, with coefficient of determination R2 of 0.83, 0.76, and 0.60 (n = 41), respectively. PMID:26016907

  17. Assessment of airborne asbestos exposure at an asbestos cement sheet and pipe factory in Iran.

    PubMed

    Marioryad, Hossein; Kakooei, Hossein; Shahtaheri, Seyed Jamaleddin; Yunesian, Masud; Azam, Kamal

    2011-07-01

    Iran imports nearly 55,000 metric tons of asbestos per year, and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, asbestos fiber concentrations during AC sheet and pipe manufacturing were measured by phase-contrast microscopy (PCM) and polarized light microscopy (PLM) in 98 personal air samples. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Personal monitoring of fiber levels indicated a range from 0.02 to 0.55PCM f/ml (0.02-0.69PLM f/ml). The AC workers' geometric mean asbestos exposure was 0.09 PCM f/ml (0.11 PLM f/ml), with arithmetic mean of 0.13 PCM f/ml (0.16 PLM f/ml). The observed fiber concentrations in many processes were higher than the threshold limit value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), which is 0.1 f/ml. Based on these findings, the PLM values were approximately 25% higher than PCM values. The SEM data demonstrate that fibrous particles contained chrysotile. The thinnest fiber recognized by SEM had a diameter of 0.2μm. Mean exposure exceeded the TLV for asbestos in pipe molding and finishing (100%) as well as sheet molding and finishing (45.5-83.3%). In conclusion exposure control may be needed to be in compliance with the ACGIH TLV and other guidance levels. Also, with regard to PCM limitations for airborne fiber analysis, the use of microscopic methods other than PCM can be used to improve the techniques used presently.

  18. Assessing and correcting topographic effects on forest canopy height retrieval using airborne LiDAR data.

    PubMed

    Duan, Zhugeng; Zhao, Dan; Zeng, Yuan; Zhao, Yujin; Wu, Bingfang; Zhu, Jianjun

    2015-05-26

    Topography affects forest canopy height retrieval based on airborne Light Detection and Ranging (LiDAR) data a lot. This paper proposes a method for correcting deviations caused by topography based on individual tree crown segmentation. The point cloud of an individual tree was extracted according to crown boundaries of isolated individual trees from digital orthophoto maps (DOMs). Normalized canopy height was calculated by subtracting the elevation of centres of gravity from the elevation of point cloud. First, individual tree crown boundaries are obtained by carrying out segmentation on the DOM. Second, point clouds of the individual trees are extracted based on the boundaries. Third, precise DEM is derived from the point cloud which is classified by a multi-scale curvature classification algorithm. Finally, a height weighted correction method is applied to correct the topological effects. The method is applied to LiDAR data acquired in South China, and its effectiveness is tested using 41 field survey plots. The results show that the terrain impacts the canopy height of individual trees in that the downslope side of the tree trunk is elevated and the upslope side is depressed. This further affects the extraction of the location and crown of individual trees. A strong correlation was detected between the slope gradient and the proportions of returns with height differences more than 0.3, 0.5 and 0.8 m in the total returns, with coefficient of determination R2 of 0.83, 0.76, and 0.60 (n = 41), respectively.

  19. Off-site population radiological dose and risk assessment for potential airborne emissions from the Weldon Spring Site

    SciTech Connect

    Avci, H.I.; Biwer, B.M.; Blunt, D.L.

    1992-11-01

    Radiological doses and health risks to the population around the Weldon Spring site from potential airborne emissions during remedial action at the chemical plant area of the site have been assessed with the Clean Air Act Assessment Package-1988 computer code. Two treatment options are being considered for waste produced by site cleanup activities: chemical stabilization/solidification and vitrification. Over the entire cleanup period of 7 years, the collective dose received by the people who live within 80 km (50 mi) of the site (about 3 million persons) is estimated to be about 34 person-rem for the chemical stabilization/ solidification option and 32 person-rem for the vitrification option. By comparison, the same population is expected to receive about 6 {times} 10{sup 6} person-rem from natural background radiation during that time. If only the population within a reasonable radius of impact is considered (about 10,700 persons live within 5 km [3 mi] of the site), the remedial action activities are estimated to result in about 5 person-rem over the entire cleanup period; the same population is expected to receive about 20,000 person-rem from natural background radiation during that time. Because the doses are low, no cancers or genetic effects are expected to occur among the population around the Weldon Spring site as a result of exposures resulting from potential radioactive releases to the atmosphere during remediation of the chemicalplant area.

  20. Off-site population radiological dose and risk assessment for potential airborne emissions from the Weldon Spring Site

    SciTech Connect

    Avci, H.I.; Biwer, B.M.; Blunt, D.L.

    1992-11-01

    Radiological doses and health risks to the population around the Weldon Spring site from potential airborne emissions during remedial action at the chemical plant area of the site have been assessed with the Clean Air Act Assessment Package-1988 computer code. Two treatment options are being considered for waste produced by site cleanup activities: chemical stabilization/solidification and vitrification. Over the entire cleanup period of 7 years, the collective dose received by the people who live within 80 km (50 mi) of the site (about 3 million persons) is estimated to be about 34 person-rem for the chemical stabilization/ solidification option and 32 person-rem for the vitrification option. By comparison, the same population is expected to receive about 6 [times] 10[sup 6] person-rem from natural background radiation during that time. If only the population within a reasonable radius of impact is considered (about 10,700 persons live within 5 km [3 mi] of the site), the remedial action activities are estimated to result in about 5 person-rem over the entire cleanup period; the same population is expected to receive about 20,000 person-rem from natural background radiation during that time. Because the doses are low, no cancers or genetic effects are expected to occur among the population around the Weldon Spring site as a result of exposures resulting from potential radioactive releases to the atmosphere during remediation of the chemicalplant area.

  1. Mathematical models for assessing the role of airflow on the risk of airborne infection in hospital wards

    PubMed Central

    Noakes, Catherine J.; Sleigh, P. Andrew

    2009-01-01

    Understanding the risk of airborne transmission can provide important information for designing safe healthcare environments with an appropriate level of environmental control for mitigating risks. The most common approach for assessing risk is to use the Wells–Riley equation to relate infectious cases to human and environmental parameters. While it is a simple model that can yield valuable information, the model used as in its original presentation has a number of limitations. This paper reviews recent developments addressing some of the limitations including coupling with epidemic models to evaluate the wider impact of control measures on disease progression, linking with zonal ventilation or computational fluid dynamics simulations to deal with imperfect mixing in real environments and recent work on dose–response modelling to simulate the interaction between pathogens and the host. A stochastic version of the Wells–Riley model is presented that allows consideration of the effects of small populations relevant in healthcare settings and it is demonstrated how this can be linked to a simple zonal ventilation model to simulate the influence of proximity to an infector. The results show how neglecting the stochastic effects present in a real situation could underestimate the risk by 15 per cent or more and that the number and rate of new infections between connected spaces is strongly dependent on the airflow. Results also indicate the potential danger of using fully mixed models for future risk assessments, with quanta values derived from such cases less than half the actual source value. PMID:19812072

  2. A model for the assessment of aquifer contamination potential based on regional geologic framework

    USGS Publications Warehouse

    Soller, D.R.; Berg, R.C.

    1992-01-01

    The texture and three-dimensional framework of geologic materials should be considered in assessments of groundwater's vulnerability to contamination because geology controls the movement of contaminants and groundwater and influences groundwater quality. Contaminants are introduced into, transmitted through, and stored by geologic materials. We present a model that identifies aquifers and ranks sequences of geologic materials by their relative potential for transmitting water and contaminants from land surface. With this basis, the model can be used to assess the potential for contamination of aquifers by surface activities such as landfitling of wastes or application of agricultural chemicals. A regional map of aquifer contamination potential can be generated from the model; it retains the geologic map information intact and available for reinterpretation or other uses. The model was developed using broad, regional map information and is intended to be a general tool for assessing the regional vulnerability of aquifers to contamination. It is not intended for local, site-specific use, but for prioritizing local areas where contamination potential and/or land-use history warrant more detailed assessment or monitoring. Because it provides a regional view of contamination potential, regional patterns or trends of map units should be evaluated, rather than using the map information literally to assess local areas. Methods of applying this model and contamination potential map to groundwater protection and management are currently being studied; research includes an attempt to statistically validate the model with water-quality data, and to identify natural groupings of the ranked contamination potential map units. ?? 1992 Springer-Verlag New York Inc.

  3. Airborne Transparencies.

    ERIC Educational Resources Information Center

    Horne, Lois Thommason

    1984-01-01

    Starting from a science project on flight, art students discussed and investigated various means of moving in space. Then they made acetate illustrations which could be used as transparencies. The projection phenomenon made the illustrations look airborne. (CS)

  4. Equilibrium Partitioning Approach for Assessing Toxicity of Contaminants in Sediments: Linking Measured Concentrations to Effects

    EPA Science Inventory

    A variety of approaches exist for assessing the degree, extent and/or risk of metals contamination in sediments. Selection of the “correct” approach depends on the nature of the question being asked (e.g., the degree of metals contamination in marine sediments may be estimated by...

  5. Assessing the bioavailability and risk from metal contaminated soils and dusts#

    EPA Science Inventory

    Exposure to contaminated soil and dust is an important pathway in human and ecological risk assessment and often is the "risk-driver" for metal contaminated soil. Site-specific soil physical and chemical characteristics, as well as biological factors, determine the bioavailabilit...

  6. [Assessment of risk of contamination of drinking water for the health of children in Tula region].

    PubMed

    Grigor'ev, Iu I; Liapina, N V

    2013-01-01

    The hygienic analysis of centralized drinking water supply in Tula region has been performed Thepriority contaminants of drinking water have been detected On the basis of risk assessment methodology non-carcinogenic health risks to the child population was calculated. A direct relationship between the incidence of some diseases in childhood population and pollution by chemical contaminants of drinking water has been established.

  7. Emerging contaminants: presentations at the 2009 Toxicology and Risk Assessment Conference.

    PubMed

    Murnyak, George; Vandenberg, John; Yaroschak, Paul J; Williams, Larry; Prabhakaran, Krishnan; Hinz, John

    2011-07-15

    A session entitled "Emerging Contaminants" was held in April 2009 in Cincinnati, OH at the 2009 Toxicology and Risk Assessment Conference. The purpose of the session was to share information on both programmatic and technical aspects associated with emerging contaminants. Emerging contaminants are chemicals or materials that are characterized by a perceived or real threat to human health or environment, a lack of published health standards or an evolving standard. A contaminant may also be "emerging" because of the discovery of a new source, a new pathway to humans, or a new detection method or technology. The session included five speakers representing the Department of Defense (DoD), the Environmental Protection Agency (EPA), and each of the military services. The DoD created the Emerging Contaminant Directorate to proactively address environmental, health, and safety concerns associated with emerging contaminants. This session described the scan-watch-action list process, impact assessment methodology, and integrated risk management concept that DoD has implemented to manage emerging contaminants. EPA presented emerging trends in health risk assessment. Researchers made technical presentations on the status of some emerging contaminates in the assessment process (i.e. manganese, RDX, and naphthalene). PMID:21034762

  8. Emerging contaminants: Presentations at the 2009 Toxicology and Risk Assessment Conference

    SciTech Connect

    Murnyak, George; Vandenberg, John; Yaroschak, Paul J.; Williams, Larry; Prabhakaran, Krishnan; Hinz, John

    2011-07-15

    A session entitled 'Emerging Contaminants' was held in April 2009 in Cincinnati, OH at the 2009 Toxicology and Risk Assessment Conference. The purpose of the session was to share information on both programmatic and technical aspects associated with emerging contaminants. Emerging contaminants are chemicals or materials that are characterized by a perceived or real threat to human health or environment, a lack of published health standards or an evolving standard. A contaminant may also be 'emerging' because of the discovery of a new source, a new pathway to humans, or a new detection method or technology. The session included five speakers representing the Department of Defense (DoD), the Environmental Protection Agency (EPA), and each of the military services. The DoD created the Emerging Contaminant Directorate to proactively address environmental, health, and safety concerns associated with emerging contaminants. This session described the scan-watch-action list process, impact assessment methodology, and integrated risk management concept that DoD has implemented to manage emerging contaminants. EPA presented emerging trends in health risk assessment. Researchers made technical presentations on the status of some emerging contaminates in the assessment process (i.e. manganese, RDX, and naphthalene).

  9. A Performance Assessment of an Airborne Separation Assistance System Using Realistic Complex Traffic Flows

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of a tactical Airborne Separation Assistance System (ASAS) in en route airspace, under varying demand levels, with realistic traffic flows. The ASAS concept studied here allows flight crews of equipped aircraft to perform separation from other air traffic autonomously. This study addresses the tactical aspects of an ASAS using aircraft state data (i.e. position and velocity) to detect and resolve projected conflicts. In addition, use of a conflict prevention system helps ASAS-equipped aircraft avoid maneuvers that may cause new conflicts. ASAS-capable aircraft are equipped with satellite-based navigation and Automatic Dependent Surveillance Broadcast (ADS-B) for transmission and receipt of aircraft state data. In addition to tactical conflict detection and resolution (CD&R), a complete, integrated ASAS is likely to incorporate a strategic CD&R component with a longer look-ahead time, using trajectory intent information. A system-wide traffic flow management (TFM) component, located at the FAA command center helps aircraft to avoid regions of excessive traffic density and complexity. A Traffic Alert and Collision Avoidance System (TCAS), as used today is the system of last resort. This integrated approach avoids sole reliance on the use of the tactical CD&R studied here, but the tactical component remains a critical element of the complete ASAS. The focus of this paper is to determine to what extent the proposed tactical component of ASAS alone can maintain aircraft separation at demand levels up to three times that of current traffic. The study also investigates the effect of mixing ASAS-equipped aircraft with unequipped aircraft (i.e. current day) that do not have the capability to self-separate. Position and velocity data for unequipped aircraft needs to be available to ASASequipped. Most likely, for this future concept, state data would be available from instrument flight rules (IFR

  10. Assessment of contaminants in Dubai coastal region, United Arab Emirates

    NASA Astrophysics Data System (ADS)

    Al-Darwish, H. A.; Abd El-Gawad, E. A.; Mohammed, F. H.; Lotfy, M. M.

    2005-12-01

    Coastal uses and other human activities have inevitably impinged on the Gulf environment; therefore, these regions require continuous monitoring. The investigated area covered the maximum fragments of Dubai coastal region in the Arabian Gulf. The determination of major oxides and trace metal concentrations in Dubai sediments revealed three heavily and moderately contaminated regions. One is in the far northeastern part at Al-Hamriya Sts 1 3 and contaminated by Fe, Cu, Pb, and Zn; the second is in the mid-northeastern part at Dry Docks and contaminated by Cu, Ni, Pb, and Zn; and finally, the third is in the near southwestern part at Dubal and contaminated by Fe, Mg, Cr, Ni, and Zn. Al-Hamriya St 3 represented the highest values of Cu, Pb, and Zn, whereas Dubal exhibited the maximum values of Fe, Mg, Ba, Cr, Mn, Ni, and V. The anthropogenic discharge and natural deposits are the main sources of contamination. In general, all trace and major elements showed the minimal levels at Jebel Ali Sanctuary (Sts 11, 12, 13) except for Sr and Ca, which showed their maximum values. The highest concentrations of Ca and Sr are mainly attributed to carbonate gravel sands and sands, which cover most stations. Each of V and Ni showed negative correlation with TPH, which may be indicated that the source of oil contamination in the region is not related to crude oil but mostly attributable to anthropogenic sources. The significant positive correlation, which was found between trace metals and TOC indicates that organic matter plays an important role in the accumulation of trace metals in case of Cu, Zn, and Pb.

  11. Geomorphological assessment of sediment contamination in an urban stream system

    USGS Publications Warehouse

    Rhoads, B.L.; Cahill, R.A.

    1999-01-01

    Little is known about the influence of fluvial-geomorphological features on the dispersal of sediment-related contaminants in urban drainage systems. This study investigates the relation between reach-scale geomorphological conditions and network-scale patterns of trace-element concentrations in a partially urbanized stream system in East-Central Illinois, USA Robust statistical analysis of bulk sediment samples reveals levels of Cr, Cu, Pb, Ni, and Zn exceed contamination thresholds in the portion of the watershed in close proximity to potential sources of pollution-in this case storm-sewer outfalls. Although trace-element concentrations decrease rapidly downstream from these sources, substantial local variability in metal levels exists within contaminated reaches. This local variability is related to reach-scale variation in fluvial-geomorphic conditions, which in turn produces variation in the degree of sorting and organic-matter content of bed material. Metal concentrations at contaminated sites also exhibit considerable variability over time. Analytical tests on specific size fractions of material collected at a highly contaminated site indicate that Cr and Ni are concentrated in the 0.063 to 0.250 mm fraction of the sediment. This fraction also has elevated concentration of Zr. SEM analysis shows that the fine sand fraction contains shards of stainless steel within a matrix of zircon sand, an industrial material associated with a nearby alloy casting operation. Samples of suspended load and bedload at the contaminated site also have elevated amounts of trace metals, but concentrations of Ni and Cr in the bedload are less than concentrations in the bed material, suggesting that these trace elements are relatively immobile. Off the other hand, amounts of CU and Zn in the bedload exceed concentrations in the bed material, implying that these trace metals are preferentially mobilized during transport events.

  12. Use of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research

    PubMed Central

    MAXWELL, SUSAN K.; MELIKER, JAYMIE R.; GOOVAERTS, PIERRE

    2015-01-01

    In recent years, geographic information systems (GIS) have increasingly been used for reconstructing individual-level exposures to environmental contaminants in epidemiological research. Remotely sensed data can be useful in creating space-time models of environmental measures. The primary advantage of using remotely sensed data is that it allows for study at the local scale (e.g., residential level) without requiring expensive, time-consuming monitoring campaigns. The purpose of our study was to identify how land surface remotely sensed data are currently being used to study the relationship between cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessment applications. We present the results of a comprehensive literature review of epidemiological research where remotely sensed imagery or land cover maps derived from remotely sensed imagery were applied. We also discuss the strengths and limitations of the most commonly used imagery data (aerial photographs and Landsat satellite imagery) and land cover maps. PMID:19240763

  13. Use of land surface remotely sensed satellite and airborne data for environmental exposure assessment in cancer research

    USGS Publications Warehouse

    Maxwell, S.K.; Meliker, J.R.; Goovaerts, P.

    2010-01-01

    In recent years, geographic information systems (GIS) have increasingly been used for reconstructing individual-level exposures to environmental contaminants in epidemiological research. Remotely sensed data can be useful in creating space-time models of environmental measures. The primary advantage of using remotely sensed data is that it allows for study at the local scale (e.g., residential level) without requiring expensive, time-consuming monitoring campaigns. The purpose of our study was to identify how land surface remotely sensed data are currently being used to study the relationship between cancer and environmental contaminants, focusing primarily on agricultural chemical exposure assessment applications. We present the results of a comprehensive literature review of epidemiological research where remotely sensed imagery or land cover maps derived from remotely sensed imagery were applied. We also discuss the strengths and limitations of the most commonly used imagery data (aerial photographs and Landsat satellite imagery) and land cover maps. ?? 2010 Nature Publishing Group All rights reserved.

  14. ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS

    SciTech Connect

    R.H. Little, P.R. Maul, J.S.S. Penfoldag

    2003-02-27

    This paper describes and presents the findings from two studies undertaken for the European Commission to assess the long-term impact upon the environment and human health of non-radioactive contaminants found in various low level radioactive waste streams. The initial study investigated the application of safety assessment approaches developed for radioactive contaminants to the assessment of nonradioactive contaminants in low level radioactive waste. It demonstrated how disposal limits could be derived for a range of non-radioactive contaminants and generic disposal facilities. The follow-up study used the same approach but undertook more detailed, disposal system specific calculations, assessing the impacts of both the non-radioactive and radioactive contaminants. The calculations undertaken indicated that it is prudent to consider non-radioactive, as well as radioactive contaminants, when assessing the impacts of low level radioactive waste disposal. For some waste streams with relatively low concentrations of radionuclides, the potential post-closure disposal impacts from non-radioactive contaminants can be comparable with the potential radiological impacts. For such waste streams there is therefore an added incentive to explore options for recycling the materials involved wherever possible.

  15. Control and assessment of the hydrocarbon contamination of Ukrainian soils

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, N. N.

    2008-05-01

    Regularities governing the self-purification of soils from oil hydrocarbons, as well as migration of hydrocarbons, and the effect on the water-physical properties and fertility of soils were revealed in a series of experiments. A system of ecological, economic, and reclamation standards was proposed for regulating economic activities in the case of soil contamination with hydrocarbons.

  16. Assessment of exposures to fecally-contaminated recreational water

    EPA Science Inventory

    Exposure to fecally-contaminated recreational waters can pose a health risk to swimmers and other recreators. Since 2003, we have interviewed nearly 27,000 respondents at seven beaches impacted by treated sewage discharge. Information was collected about the duration and exposure...

  17. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES, INCLUDING INTERSPECIES TOXICITY CORRELATIONS

    EPA Science Inventory

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accorda...

  18. ASSESSING CONTAMINANT SENSITIVITY OF ENDANGERED AND THREATENED SPECIES: 3. EFFLUENT TOXICITY TESTS

    EPA Science Inventory

    Dwyer, F. James, Douglas K. Hardesty, Christopher E. Henke, Christopher G. Ingersoll, David W. Whites, Tom Augspurger, Timothy J. Canfield, David R. Mount and Foster L. Mayer. Submitted. Assessing Contaminant Sensitivity of Endangered and Threatened Species: 3. Effluent Tests. Ar...

  19. Mapping, Assessment and Analysis of Large-Scale Landslides Based on Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Elsner, Bernhard

    2015-04-01

    In the context of the integrated risk management of the Austrian Service for Torrent and Avalanche Control (WLV) large-scale landslides - per definition only areas larger than 10 ha - were mapped in a study area in the South of Innsbruck/Tyrol. The large-scale landslides to be identified are mostly very slow and deep-seated including complex processes like mountain slope deformations ("Talzuschübe"). The mapping method for the first time developed in this study is based on hillshades of high-resolution airborne LIDAR data which recently has been made nearly nationwide available for Austria. These data have the advantage faced with other remote-sensing data like orthophotos that dense and high vegetation and other distracting objects on the ground are eliminated. This guarantees everywhere a high visibility of the terrain surface which is very helpful for the detection of landslides. These aspects allowed developing a new systematic approach for the identification and rough classification of large-scale landslides according to their activity. Using an iterative comparison of first results with other existing methods and field observations the methodology was developed as objective as possible. For this reason these landslides are divided in four distinct segments showing typical characteristics like double ridges or a surface of rupture. According to the characteristics and to the importance of these four segments all detected landslides are then assigned to one of the four classes of activity: "active", "likely active", "inactive" or "possibly inactive". Using this method, large-scale landslides were identified in 26 % of the entire study area. The major part of these landslides (65 %) is supposed to be "inactive" and only 0.5 % are classified as "active". In addition some analyses in the context of natural hazard research were carried out to interpret the quantitative occurrence and spatial distribution of the mapped landslides. Glacial overdeepening in valleys

  20. Assessment of airborne heavy metal pollution in soil and lichen in the Meric-Ergene Basin, Turkey.

    PubMed

    Hanedar, Asude

    2015-01-01

    In the present study, accumulations of airborne heavy metals in lichen and soil samples were determined on the basis of pollutant source groups by conducting Zinc (Zn), Lead (Pb), Iron (Fe), Copper (Cu), Chromium (Cr), Cadmium (Cd), Arsenic (As), Cobalt (Co) and Manganese (Mn) analyses on a total of 48 samples collected in the periods of May 2014 and August 2014 from 12 sampling points in a heavily industrialized area, a mixed industrial and residential area, an agricultural area and a background area in the Meric-Ergene Basin, and pH and total organic carbon determination was carried out on soil samples. With the obtained data, heavy metal levels were statistically assessed in detail by being associated with each other and with their probable sources; the accumulations found in soil and lichen samples were compared and spatial variances were set forth. Based on the results, it was observed that heavy metal pollution is at high levels particularly in industrialized areas, and that the differences between the cleanest and most polluted levels determined from soil samples for As, Cr, Cd and Pb reach 10 folds. The highest levels of all heavy metals were determined in both the soil and lichen samples collected from the areas in the south-east part of the region, where industrial activities and particularly leather and chemical industries are concentrated. With the comparison of the indication properties of soil and lichen, it was determined that significant and comparable results can be observed in both matrices.

  1. Analysis of Variation in Total Airborne Bacteria Concentration to Assess the Performance of Biological Safety Cabinets in Microbial Laboratories

    PubMed Central

    Hwang, Sung Ho; Park, Hyun Hee; Yoon, Chung Sik

    2014-01-01

    Background The purpose of this study was to compare the concentration of total airborne bacteria (TAB) in biosafety cabinets (BSCs) at universities and hospital microbial laboratories to assess the performance of BSCs. Methods TAB was determined by using the single-stage Anderson sampler (BioStage Viable Cascade Impactor). The samples were obtained three times (with the BSC turned off and the shield open; with the BSC turned off and the shield closed; and with the BSC tuned on and operating) from the areas in front of 11 BSCs. Results TAB concentrations of accredited and nonaccredited BSCs were determined. No significant differences were observed in the TAB concentrations of the accredited BSCs and the nonaccredited BSCs for the areas outside the BSCs in the laboratories (p > 0.05). TAB concentrations for the BSCs sampled with the shield open and the instrument turned off showed differences based on the sampling site outside the BSC in each laboratory. Conclusion These results imply that TAB concentration is not altered by the performance of the BSCs or TAB itself and/or concentration of TAB outside the BSC is not a good index of BSC performance. PMID:24932416

  2. Assessment of EOS Aqua AMSR-E Arctic Sea Ice Concentrations using Landsat-7 and Airborne Microwave Imagery

    NASA Technical Reports Server (NTRS)

    Cavalieri, Donald J.; Markus, Thorsten; Hall, Dorothy K.; Gasiewski, Albin J.; Klein, Marian; Ivanoff, Alvaro

    2006-01-01

    An assessment of Advanced Microwave Scanning Radiometer Earth Observing System (AMSR-E) sea ice concentrations under winter conditions using ice concentrations derived from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) imagery obtained during the March 2003 Arctic sea ice validation field campaign is presented. The National Oceanic and Atmospheric Administration Environmental Technology Laboratory's Airborne Polarimetric Scanning Radiometer Measurements, which were made from the National Aeronautics and Space Administration P 3B aircraft during the campaign, were used primarily as a diagnostic tool to understand the comparative results and to suggest improvements to the AMSR-E ice concentration algorithm. Based on the AMSR-E/ETM+ comparisons, a good overall agreement with little bias (approx. 1%) for areas of first year and young sea ice was found. Areas of new ice production result in a negative bias of about 5% in the AMSR-E ice concentration retrievals, with a root mean square error of 8%. Some areas of deep snow also resulted in an underestimate of the ice concentration (approx. 10%). For all ice types combined and for the full range of ice concentrations, the bias ranged from 0% to 3%, and the rms errors ranged from 1% to 7%, depending on the region. The new-ice and deep-snow biases are expected to be reduced through an adjustment of the new-ice and ice-type C algorithm tie points.

  3. Assessing the application of an airborne intensified multispectral video camera to measure chlorophyll a in three Florida estuaries

    SciTech Connect

    Dierberg, F.E.; Zaitzeff, J.

    1997-08-01

    After absolute and spectral calibration, an airborne intensified, multispectral video camera was field tested for water quality assessments over three Florida estuaries (Tampa Bay, Indian River Lagoon, and the St. Lucie River Estuary). Univariate regression analysis of upwelling spectral energy vs. ground-truthed uncorrected chlorophyll a (Chl a) for each estuary yielded lower coefficients of determination (R{sup 2}) with increasing concentrations of Gelbstoff within an estuary. More predictive relationships were established by adding true color as a second independent variable in a bivariate linear regression model. These regressions successfully explained most of the variation in upwelling light energy (R{sup 2}=0.94, 0.82 and 0.74 for the Tampa Bay, Indian River Lagoon, and St. Lucie estuaries, respectively). Ratioed wavelength bands within the 625-710 nm range produced the highest correlations with ground-truthed uncorrected Chl a, and were similar to those reported as being the most predictive for Chl a in Tennessee reservoirs. However, the ratioed wavebands producing the best predictive algorithms for Chl a differed among the three estuaries due to the effects of varying concentrations of Gelbstoff on upwelling spectral signatures, which precluded combining the data into a common data set for analysis.

  4. Recent advances in containment assessment offer proactive alternatives for managing contaminated fisheries

    SciTech Connect

    Bevelhimer, M.S.

    1995-12-01

    For a variety of reasons, many fisheries managers seem reluctant to get involved in contaminant issues even though the effect on fisheries can be far-reaching. The involvement of fisheries managers in this process is critical, and recent advances in assessment techniques offer hope that a more active management of contaminated fisheries is possible. Managing contaminated systems is often limited to contaminant analysis of fish tissue (and sometimes water and sediment), community surveys, and posting of consumption advisories. New approaches using advanced statistical analyses, simulation modeling, and bioindicators of environmental stress offer additional tools that can be used to better understand the transport and fate of contaminants, to assess potential ecological injury, and to evaluate proposed remedial actions. For these tools to be useful in management situations, managers and researchers will need to cooperate in both the development and use of these new techniques. 29 refs.

  5. Cumulative health risk assessment: integrated approaches for multiple contaminants, exposures, and effects

    SciTech Connect

    Rice, Glenn; Teuschler, Linda; MacDonel, Margaret; Butler, Jim; Finster, Molly; Hertzberg, Rick; Harou, Lynne

    2007-07-01

    Available in abstract form only. Full text of publication follows: As information about environmental contamination has increased in recent years, so has public interest in the combined effects of multiple contaminants. This interest has been highlighted by recent tragedies such as the World Trade Center disaster and hurricane Katrina. In fact, assessing multiple contaminants, exposures, and effects has long been an issue for contaminated sites, including U.S. Department of Energy (DOE) legacy waste sites. Local citizens have explicitly asked the federal government to account for cumulative risks, with contaminants moving offsite via groundwater flow, surface runoff, and air dispersal being a common emphasis. Multiple exposures range from ingestion and inhalation to dermal absorption and external gamma irradiation. Three types of concerns can lead to cumulative assessments: (1) specific sources or releases - e.g., industrial facilities or accidental discharges; (2) contaminant levels - in environmental media or human tissues; and (3) elevated rates of disease - e.g., asthma or cancer. The specific initiator frames the assessment strategy, including a determination of appropriate models to be used. Approaches are being developed to better integrate a variety of data, extending from environmental to internal co-location of contaminants and combined effects, to support more practical assessments of cumulative health risks. (authors)

  6. Airborne data acquisition techniques

    SciTech Connect

    Arro, A.A.

    1980-01-01

    The introduction of standards on acceptable procedures for assessing building heat loss has created a dilemma for the contractor performing airborne thermographic surveys. These standards impose specifications on instrumentation, data acquisition, recording, interpretation, and presentation. Under the standard, the contractor has both the obligation of compliance and the requirement of offering his services at a reasonable price. This paper discusses the various aspects of data acquisition for airborne thermographic surveys and various techniques to reduce the costs of this operation. These techniques include the calculation of flight parameters for economical data acquisition, the selection and use of maps for mission planning, and the use of meteorological forecasts for flight scheduling and the actual execution of the mission. The proper consideration of these factors will result in a cost effective data acquisition and will place the contractor in a very competitive position in offering airborne thermographic survey services.

  7. Possibilities of implementation of bioavailability methods for organic contaminants in the Dutch Soil Quality Assessment Framework.

    PubMed

    Brand, Ellen; Lijzen, Johannes; Peijnenburg, Willie; Swartjes, Frank

    2013-10-15

    In the Netherlands, risk assessment of contaminated soils is based on determining the total contaminant concentration. If this measured soil concentration exceeds the Soil Quality Standards (SQS) a higher tier risk evaluation must be performed. Experiences from the field have given rise to the perception that performing risk evaluations based on (measured) total concentrations may lead to an inaccurate assessment of the actual risks. Assuming that only the bioavailable fraction is capable of exerting adverse effects in the soil ecosystem, it is suggested, that by taking bioavailability into account in a (higher tier) risk evaluation, a more effect-based risk assessment can be performed. Bioavailability has been a subject of research for several decades. However up to now bioavailability has not been implemented in the Dutch Soil Quality Assessment Framework. First actions were taken in the Netherlands to determine whether the concept of bioavailability could be implemented in the risk assessment of contaminated soils and to find out how bioavailability can become part of the Dutch Soil Quality Assessment Framework. These actions have led to a concrete proposal for implementation of bioavailability methods in the risk assessment of organic contaminants in soils. This paper focuses on the chemical prediction of bioavailability for ecological risk assessment of contaminated soils.

  8. The exposure assessment of airborne particulates matter (PM10 & PM2.5) towards building occupants: A case study at KL Sentral, Kuala Lumpur, Malaysia

    NASA Astrophysics Data System (ADS)

    Mohddin, S. A.; Aminuddin, N. M.

    2014-02-01

    Airborne particulates have been recognized as a crucial pollutant of indoor air. These pollutants can contribute towards poor indoor air quality (IAQ), which may affect human health in immediate or long term. This study aims to determine the level of IAQ and the effects of particulate towards occupants of office buildings (the office buildings selected for the case study are SSM, KTMB and MRCB at KL Sentral). The objectives of study are (i) to measure the level of airborne particulates that contribute to the IAQ during working hours, (ii) to compare the level of airborne particulates with the existing guidelines and standards of IAQ in Malaysia and other Asian countries and (iii) to assess the symptoms associated with airborne particulates among the building occupants, which were achieved through primary data collection (case study or site survey, structured interview and questionnaire survey) and supported by literature reviews. The results showed that the mass concentration level of airborne particulates within the areas has exceeded the allowable limit of 0.15mg/m3 by IAQ Code of Practice, 2005 of the Department of Safety and Health (DOSH), Malaysia and 0.05mg/m3 by the Department of Environmental (DOE) (outdoor) of 8 hours continuous sampling. Based on the findings, the highest mass concentration values measured is 2.581 mg/m3 at lobby of SSM building which is the highest recorded 17 times higher from the maximum limit recommended by DOSH than the others. This is due to the nearby construction works and the high numbers of particulates are generated from various types of vehicles for transportation surrounding KL Sentral. Therefore, the development of Malaysian Ambient Air Quality Guidelines on PM2.5 as one of the crucial parameters is highly recommended.

  9. Site-specific risk assessment in contaminated vegetable gardens.

    PubMed

    Sipter, Emese; Rózsa, Eniko; Gruiz, Katalin; Tátrai, Erzsébet; Morvai, Veronika

    2008-04-01

    A field survey was carried on in Gyöngyösoroszi, Hungary, near to an abandoned lead/zinc mine to analyse the metal contamination of flooded and non-flooded vegetable gardens, and to evaluate the health risks to local population. Contamination levels of arsenic, cadmium, lead, mercury and zinc were measured in soil and homegrown vegetable samples and bioconcentration factors and hazard indices were calculated. The high metal contents of flooded vegetable gardens were caused by floods, the results indicated significant differences between flooded and non-flooded vegetable gardens. The most accumulating vegetable was sorrel, the most mobile elements were cadmium and lead. Arsenic was not available for vegetables. The health risk was calculated for two exposure routes: ingestion of soil and ingestion of vegetables. The site-specific exposure parameters were established after a population based survey and a special equation was created to calculate the health risk due to homegrown vegetable consumption. The highest risk was associated with ingestion of vegetables, the most hazardous element being lead. The hazard index did not exceed the threshold value of one in flooded or non-flooded gardens. The analyses of health risk indicated that despite the high metal concentrations of soil the contamination of vegetable gardens does not pose an unacceptable risk to the inhabitants of the village. PMID:18191173

  10. National rivers and streams assessment: fish tissue contaminants

    EPA Science Inventory

    Overview of the National Rivers and Streams Assessment (NRSA), a statistical survey of flowing waters in the U.S. Survey is designed to: assess the condition of the nation's rivers and streams; help build state and tribal capacity for monitoring and assessment; promote collabor...

  11. Decision support methods for the environmental assessment of contamination at mining sites.

    PubMed

    Jordan, Gyozo; Abdaal, Ahmed

    2013-09-01

    Polluting mine accidents and widespread environmental contamination associated with historic mining in Europe and elsewhere has triggered the improvement of related environmental legislation and of the environmental assessment and management methods for the mining industry. Mining has some unique features such as natural background pollution associated with natural mineral deposits, industrial activities and contamination located in the three-dimensional sub-surface space, the problem of long-term remediation after mine closure, problem of secondary contaminated areas around mine sites and abandoned mines in historic regions like Europe. These mining-specific problems require special tools to address the complexity of the environmental problems of mining-related contamination. The objective of this paper is to review and evaluate some of the decision support methods that have been developed and applied to mining contamination. In this paper, only those methods that are both efficient decision support tools and provide a 'holistic' approach to the complex problem as well are considered. These tools are (1) landscape ecology, (2) industrial ecology, (3) landscape geochemistry, (4) geo-environmental models, (5) environmental impact assessment, (6) environmental risk assessment, (7) material flow analysis and (8) life cycle assessment. This unique inter-disciplinary study should enable both the researcher and the practitioner to obtain broad view on the state-of-the-art of decision support methods for the environmental assessment of contamination at mine sites. Documented examples and abundant references are also provided.

  12. Methods for Sampling of Airborne Viruses

    PubMed Central

    Verreault, Daniel; Moineau, Sylvain; Duchaine, Caroline

    2008-01-01

    Summary: To better understand the underlying mechanisms of aerovirology, accurate sampling of airborne viruses is fundamental. The sampling instruments commonly used in aerobiology have also been used to recover viruses suspended in the air. We reviewed over 100 papers to evaluate the methods currently used for viral aerosol sampling. Differentiating infections caused by direct contact from those caused by airborne dissemination can be a very demanding task given the wide variety of sources of viral aerosols. While epidemiological data can help to determine the source of the contamination, direct data obtained from air samples can provide very useful information for risk assessment purposes. Many types of samplers have been used over the years, including liquid impingers, solid impactors, filters, electrostatic precipitators, and many others. The efficiencies of these samplers depend on a variety of environmental and methodological factors that can affect the integrity of the virus structure. The aerodynamic size distribution of the aerosol also has a direct effect on sampler efficiency. Viral aerosols can be studied under controlled laboratory conditions, using biological or nonbiological tracers and surrogate viruses, which are also discussed in this review. Lastly, general recommendations are made regarding future studies on the sampling of airborne viruses. PMID:18772283

  13. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  14. Assessing ground-water vulnerability to contamination: Providing scientifically defensible information for decision makers

    USGS Publications Warehouse

    Focazio, Michael J.; Reilly, Thomas E.; Rupert, Michael G.; Helsel, Dennis R.

    2002-01-01

    Throughout the United States increasing demands for safe drinking water and requirements to maintain healthy ecosystems are leading policy makers to ask complex social and scientific questions about how to assess and manage our water resources. This challenge becomes particularly difficult as policy and management objectives require scientific assessments of the potential for ground-water resources to become contaminated from anthropogenic, as well as natural sources of contamination. Assessments of the vulnerability of ground water to contamination range in scope and complexity from simple, qualitative, and relatively inexpensive approaches to rigorous, quantitative, and costly assessments. Tradeoffs must be carefully considered among the competing influences of the cost of an assessment, the scientific defensibility, and the amount of acceptable uncertainty in meeting the objectives of the water-resource decision maker.

  15. Heavy Metal Contamination Assessment and Partition for Industrial and Mining Gathering Areas

    PubMed Central

    Guan, Yang; Shao, Chaofeng; Ju, Meiting

    2014-01-01

    Industrial and mining activities have been recognized as the major sources of soil heavy metal contamination. This study introduced an improved Nemerow index method based on the Nemerow and geo-accumulation index. Taking a typical industrial and mining gathering area in Tianjin (China) as example, this study then analyzed the contamination sources as well as the ecological and integrated risks. The spatial distribution of the contamination level and ecological risk were determined using Geographic Information Systems. The results are as follows: (1) Zinc showed the highest contaminant level in the study area; the contamination levels of the other seven heavy metals assessed were relatively lower. (2) The combustion of fossil fuels and emissions from industrial and mining activities were the main sources of contamination in the study area. (3) The overall contamination level of heavy metals in the study area ranged from heavily contaminated to extremely contaminated and showed an uneven distribution. (4) The potential ecological risk showed an uneven distribution, and the overall ecological risk level ranged from low to moderate. This study also emphasized the importance of partition in industrial and mining areas, the extensive application of spatial analysis methods, and the consideration of human health risks in future studies. PMID:25032743

  16. Heavy metal contamination assessment and partition for industrial and mining gathering areas.

    PubMed

    Guan, Yang; Shao, Chaofeng; Ju, Meiting

    2014-07-01

    Industrial and mining activities have been recognized as the major sources of soil heavy metal contamination. This study introduced an improved Nemerow index method based on the Nemerow and geo-accumulation index. Taking a typical industrial and mining gathering area in Tianjin (China) as example, this study then analyzed the contamination sources as well as the ecological and integrated risks. The spatial distribution of the contamination level and ecological risk were determined using Geographic Information Systems. The results are as follows: (1) Zinc showed the highest contaminant level in the study area; the contamination levels of the other seven heavy metals assessed were relatively lower. (2) The combustion of fossil fuels and emissions from industrial and mining activities were the main sources of contamination in the study area. (3) The overall contamination level of heavy metals in the study area ranged from heavily contaminated to extremely contaminated and showed an uneven distribution. (4) The potential ecological risk showed an uneven distribution, and the overall ecological risk level ranged from low to moderate. This study also emphasized the importance of partition in industrial and mining areas, the extensive application of spatial analysis methods, and the consideration of human health risks in future studies.

  17. Harvesting tree biomass at the stand level to assess the accuracy of field and airborne biomass estimation in savannas.

    PubMed

    Colgan, Matthew S; Asner, Gregory P; Swemmer, Tony

    2013-07-01

    Tree biomass is an integrated measure of net growth and is critical for understanding, monitoring, and modeling ecosystem functions. Despite the importance of accurately measuring tree biomass, several fundamental barriers preclude direct measurement at large spatial scales, including the facts that trees must be felled to be weighed and that even modestly sized trees are challenging to maneuver once felled. Allometric methods allow for estimation of tree mass using structural characteristics, such as trunk diameter. Savanna trees present additional challenges, including limited available allometry and a prevalence of multiple stems per individual. Here we collected airborne lidar data over a semiarid savanna adjacent to the Kruger National Park, South Africa, and then harvested and weighed woody plant biomass at the plot scale to provide a standard against which field and airborne estimation methods could be compared. For an existing airborne lidar method, we found that half of the total error was due to averaging canopy height at the plot scale. This error was eliminated by instead measuring maximum height and crown area of individual trees from lidar data using an object-based method to identify individual tree crowns and estimate their biomass. The best object-based model approached the accuracy of field allometry at both the tree and plot levels, and it more than doubled the accuracy compared to existing airborne methods (17% vs. 44% deviation from harvested biomass). Allometric error accounted for less than one-third of the total residual error in airborne biomass estimates at the plot scale when using allometry with low bias. Airborne methods also gave more accurate predictions at the plot level than did field methods based on diameter-only allometry. These results provide a novel comparison of field and airborne biomass estimates using harvested plots and advance the role of lidar remote sensing in savanna ecosystems.

  18. A comparative review of optical surface contamination assessment techniques

    NASA Technical Reports Server (NTRS)

    Heaney, James B.

    1987-01-01

    This paper will review the relative sensitivities and practicalities of the common surface analytical methods that are used to detect and identify unwelcome adsorbants on optical surfaces. The compared methods include visual inspection, simple reflectometry and transmissiometry, ellipsometry, infrared absorption and attenuated total reflectance spectroscopy (ATR), Auger electron spectroscopy (AES), scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS), and mass accretion determined by quartz crystal microbalance (QCM). The discussion is biased toward those methods that apply optical thin film analytical techniques to spacecraft optical contamination problems. Examples are cited from both ground based and in-orbit experiments.

  19. Human health risk assessment related to contaminated land: state of the art.

    PubMed

    Swartjes, F A

    2015-08-01

    Exposure of humans to contaminants from contaminated land may result in many types of health damage ranging from relatively innocent symptoms such as skin eruption or nausea, on up to cancer or even death. Human health protection is generally considered as a major protection target. State-of-the-art possibilities and limitations of human health risk assessment tools are described in this paper. Human health risk assessment includes two different activities, i.e. the exposure assessment and the hazard assessment. The combination of these is called the risk characterization, which results in an appraisal of the contaminated land. Exposure assessment covers a smart combination of calculations, using exposure models, and measurements in contact media and body liquids and tissue (biomonitoring). Regarding the time frame represented by exposure estimates, biomonitoring generally relates to exposure history, measurements in contact media to actual exposures, while exposure calculations enable a focus on exposure in future situations. The hazard assessment, which is different for contaminants with or without a threshold for effects, results in a critical exposure value. Good human health risk assessment practice accounts for tiered approaches and multiple lines of evidence. Specific attention is given here to phenomena such as the time factor in human health risk assessment, suitability for the local situation, background exposure, combined exposure and harmonization of human health risk assessment tools.

  20. Incorporating biologically based models into assessments of risk from chemical contaminants

    NASA Technical Reports Server (NTRS)

    Bull, R. J.; Conolly, R. B.; De Marini, D. M.; MacPhail, R. C.; Ohanian, E. V.; Swenberg, J. A.

    1993-01-01

    The general approach to assessment of risk from chemical contaminants in drinking water involves three steps: hazard identification, exposure assessment, and dose-response assessment. Traditionally, the risks to humans associated with different levels of a chemical have been derived from the toxic responses observed in animals. It is becoming increasingly clear, however, that further information is needed if risks to humans are to be assessed accurately. Biologically based models help clarify the dose-response relationship and reduce uncertainty.

  1. MERCURY CONTAMINATED MATERIAL DECONTAMINATION METHODS: INVESTIGATION AND ASSESSMENT

    SciTech Connect

    M.A. Ebadian, Ph.D.

    2001-01-01

    Over the years mercury has been recognized as having serious impacts on human health and the environment. This recognition has led to numerous studies that deal with the properties of various mercury forms, the development of methods to quantify and speciate the forms, fate and transport, toxicology studies, and the development of site remediation and decontamination technologies. This report reviews several critical areas that will be used in developing technologies for cleaning mercury from mercury-contaminated surfaces of metals and porous materials found in many DOE facilities. The technologies used for decontamination of water and mixed wastes (solid) are specifically discussed. Many technologies that have recently appeared in the literature are included in the report. Current surface decontamination processes have been reviewed, and the limitations of these technologies for mercury decontamination are discussed. Based on the currently available technologies and the processes published recently in the literature, several processes, including strippable coatings, chemical cleaning with iodine/iodide lixiviant, chemisorbing surface wipes with forager sponge and grafted cotton, and surface/pore fixation through amalgamation or stabilization, have been identified as potential techniques for decontamination of mercury-contaminated metal and porous surfaces. Their potential merits and applicability are discussed. Finally, two processes, strippable coatings and chemical cleaning with iodine/iodide lixiviant, were experimentally investigated in Phase II of this project.

  2. Assessment of combined electro-nanoremediation of molinate contaminated soil.

    PubMed

    Gomes, Helena I; Fan, Guangping; Mateus, Eduardo P; Dias-Ferreira, Celia; Ribeiro, Alexandra B

    2014-09-15

    Molinate is a pesticide widely used, both in space and time, for weed control in rice paddies. Due to its water solubility and affinity to organic matter, it is a contaminant of concern in ground and surface waters, soils and sediments. Previous works have showed that molinate can be removed from soils through electrokinetic (EK) remediation. In this work, molinate degradation by zero valent iron nanoparticles (nZVI) was tested in soils for the first time. Soil is a highly complex matrix, and pollutant partitioning between soil and water and its degradation rates in different matrices is quite challenging. A system combining nZVI and EK was also set up in order to study the nanoparticles and molinate transport, as well as molinate degradation. Results showed that molinate could be degraded by nZVI in soils, even though the process is more time demanding and degradation percentages are lower than in an aqueous solution. This shows the importance of testing contaminant degradation, not only in aqueous solutions, but also in the soil-sorbed fraction. It was also found that soil type was the most significant factor influencing iron and molinate transport. The main advantage of the simultaneous use of both methods is the molinate degradation instead of its accumulation in the catholyte. PMID:24946031

  3. Airborne engineered nanoparticles: potential risks and monitoring challenges for assessing their impacts on children.

    PubMed

    Biskos, G; Schmidt-Ott, A

    2012-06-01

    Engineered nanoparticles (ENPs) are the building blocks of novel materials and consumer products that hold great promise for our societies. When ENPs are released to the environment, however, they can induce irreversible processes that can affect human health. To ensure safety for all nanoparticle-based products throughout their life cycle we urgently need to develop techniques for determining their toxic effects and the exposure levels of humans to ENPs. In an attempt to estimate whether nanotechnology can threaten more sensitive parts of the population such as children, we provide a brief overview of the potential pathways of introducing ENPs into the environment and the state-of-the-art techniques for assessing human exposure, as well as our current knowledge on their toxic effects. PMID:22475252

  4. Malignant mesothelioma, airborne asbestos, and the need for accuracy in chrysotile risk assessments.

    PubMed

    Meisenkothen, Christopher

    2013-01-01

    A man diagnosed with pleural mesothelioma sought legal representation with the author's law firm. He worked 33 years in a wire and cable factory in the northeastern United States (Connecticut) that exclusively used chrysotile asbestos in its manufacturing process. This is the first report of mesothelioma arising from employees of this factory. This report provides additional support for the proposition that chrysotile asbestos can cause malignant mesothelioma in humans. If chrysotile risk assessments are to be accurate, then the literature should contain an accurate accounting of all mesotheliomas alleged to be caused by chrysotile asbestos. This is important not just for public health professionals but also for individuals and companies involved in litigation over asbestos-related diseases. If reports such as these remain unknown, it is probable that cases of mesothelioma among chrysotile-exposed cohorts would go unrecognized and chrysotile-using factories would be incorrectly cited as having no mesotheliomas among their employees.

  5. Approaches to assessing the risk of chemical contamination of Urban Soils

    NASA Astrophysics Data System (ADS)

    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.

  6. Integration of analytical and biological measurements for assessing the effects of contaminants present at Great Lakes areas of concern

    EPA Science Inventory

    Assessing the potential biological impacts of complex contaminant mixtures in aquatic environments is often a challenge for ecotoxicologists. Instrumental analysis of site waters provides insights into the occurrence of contaminants, but provides little information about possibl...

  7. Integration of analytical and biological measurements for assessing the effects of contaminants present at a Great Lakes area of concern

    EPA Science Inventory

    Assessing the potential biological impacts of complex contaminant mixtures in aquatic environments is a challenge. Instrumental analyses of site waters provide insights into the occurrence of contaminants, but provide little information about possible effects. Biological measur...

  8. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

    ATM (Airborne Thematic Mapper) was developed for NSTL (National Space Technology Companies) by Daedalus Company. It offers expanded capabilities for timely, accurate and cost effective identification of areas with prospecting potential. A related system is TIMS, Thermal Infrared Multispectral Scanner. Originating from Landsat 4, it is also used for agricultural studies, etc.

  9. Health risk equations and risk assessment of airborne benzene homologues exposure to drivers and passengers in taxi cabins.

    PubMed

    Chen, Xiaokai; Feng, Lili; Luo, Huilong; Cheng, Heming

    2016-03-01

    Interior air environment and health problems of vehicles have attracted increasing attention, and benzene homologues (BHs) including benzene, toluene, ethylbenzene, xylenes, and styrene are primary hazardous gases in vehicular cabins. The BHs impact on the health of passengers and drivers in 38 taxis is assessed, and health risk equations of in-car BHs to different drivers and passengers are induced. The health risk of in-car BHs for male drivers is the highest among all different receptors and is 1.04, 6.67, and 6.94 times more than ones for female drivers, male passengers, and female passengers, respectively. In-car BHs could not lead to the non-cancer health risk to all passengers and drivers as for the maximal value of non-cancer indices is 0.41 and is less than the unacceptable value (1.00) of non-cancer health risk from USEPA. However, in-car BHs lead to cancer health risk to drivers as for the average value of cancer indices is 1.21E-04 which is 1.21 times more than the unacceptable value (1.00E-04) of cancer health risk from USEPA. Finally, for in-car airborne benzene concentration (X, μg/m(3)) to male drivers, female drivers, male passengers, and female passengers, the cancer health risk equations are Y = 1.48E-06X, Y = 1.42E-06X, Y = 2.22E-07X, and Y = 2.13E-07X, respectively, and the non-cancer health risk equations are Y = 1.70E-03X, Y = 1.63E-03X, Y = 2.55E-04X, and Y = 2.45E-04X, respectively.

  10. Assessment of seismic loading on structures based on airborne LiDAR data from the Kalochori urban area (N. Greece)

    NASA Astrophysics Data System (ADS)

    Rovithis, Emmanouil; Kirtas, Emmanouil; Marini, Eleftheria; Bliziotis, Dimitris; Maltezos, Evangelos; Pitilakis, Dimitris; Makra, Konstantia; Savvaidis, Alexandros

    2016-08-01

    Airborne LiDAR monitoring integrated with field data is employed to assess the fundamental period and the seismic loading of structures composing an urban area under prescribed earthquake scenarios. Α piecewise work-flow is adopted by combining geometrical data of the building stock derived from a LiDAR-based 3D city model, structural data from in-situ inspections on representative city blocks and results of soil response analyses. The procedure is implemented in the residential area of Kalochori, (west of Thessaloniki in Northern Greece). Special attention is paid to the in-situ inspection of the building stock in order to discriminate recordings between actual buildings and man-made constructions that do not conform to seismic design codes and to acquire additional building stock data on structural materials, typologies and number of stories which is not feasible by the LiDAR process. The processed LiDAR and field data are employed to compute the fundamental period of each building by means of code-defined formulas. Knowledge of soil conditions in the Kalochoti area allows for soil response analyses to obtain free-field at ground surface under earthquake scenarios with varying return period. Upon combining the computed vibrational characteristics of the structures with the free-field response spectra, the seismic loading imposed on the structures of the urban area under investigation is derived for each one of the prescribed seismic motions. Results are presented in GIS environment in the form of spatially distributed spectral accelerations with direct implications in seismic vulnerability studies of an urban area.

  11. Simulation tests to assess occupational exposure to airborne asbestos from artificially weathered asphalt-based roofing products.

    PubMed

    Sheehan, Patrick; Mowat, Fionna; Weidling, Ryan; Floyd, Mark

    2010-11-01

    Historically, asbestos-containing roof cements and coatings were widely used for patching and repairing leaks. Although fiber releases from these materials when newly applied have been studied, there are virtually no useful data on airborne asbestos fiber concentrations associated with the repair or removal of weathered roof coatings and cements, as most studies involve complete tear-out of old roofs, rather than only limited removal of the roof coating or cement during a repair job. This study was undertaken to estimate potential chrysotile asbestos fiber exposures specific to these types of roofing products following artificially enhanced weathering. Roof panels coated with plastic roof cement and fibered roof coating were subjected to intense solar radiation and daily simulated precipitation events for 1 year and then scraped to remove the weathered materials to assess chrysotile fiber release and potential worker exposures. Analysis of measured fiber concentrations for hand scraping of the weathered products showed 8-h time-weighted average concentrations that were well below the current Occupational Safety and Health Administration permissible exposure limit for asbestos. There was, however, visibly more dust and a few more fibers collected during the hand scraping of weathered products compared to the cured products previously tested. There was a notable difference between fibers released from weathered and cured roofing products. In weathered samples, a large fraction of chrysotile fibers contained low concentrations of or essentially no magnesium and did not meet the spectral, mineralogical, or morphological definitions of chrysotile asbestos. The extent of magnesium leaching from chrysotile fibers is of interest because several researchers have reported that magnesium-depleted chrysotile fibers are less toxic and produce fewer mesothelial tumors in animal studies than normal chrysotile fibers. PMID:20923966

  12. Community-based risk assessment of water contamination from high-volume horizontal hydraulic fracturing.

    PubMed

    Penningroth, Stephen M; Yarrow, Matthew M; Figueroa, Abner X; Bowen, Rebecca J; Delgado, Soraya

    2013-01-01

    The risk of contaminating surface and groundwater as a result of shale gas extraction using high-volume horizontal hydraulic fracturing (fracking) has not been assessed using conventional risk assessment methodologies. Baseline (pre-fracking) data on relevant water quality indicators, needed for meaningful risk assessment, are largely lacking. To fill this gap, the nonprofit Community Science Institute (CSI) partners with community volunteers who perform regular sampling of more than 50 streams in the Marcellus and Utica Shale regions of upstate New York; samples are analyzed for parameters associated with HVHHF. Similar baseline data on regional groundwater comes from CSI's testing of private drinking water wells. Analytic results for groundwater (with permission) and surface water are made publicly available in an interactive, searchable database. Baseline concentrations of potential contaminants from shale gas operations are found to be low, suggesting that early community-based monitoring is an effective foundation for assessing later contamination due to fracking.

  13. Community-based risk assessment of water contamination from high-volume horizontal hydraulic fracturing.

    PubMed

    Penningroth, Stephen M; Yarrow, Matthew M; Figueroa, Abner X; Bowen, Rebecca J; Delgado, Soraya

    2013-01-01

    The risk of contaminating surface and groundwater as a result of shale gas extraction using high-volume horizontal hydraulic fracturing (fracking) has not been assessed using conventional risk assessment methodologies. Baseline (pre-fracking) data on relevant water quality indicators, needed for meaningful risk assessment, are largely lacking. To fill this gap, the nonprofit Community Science Institute (CSI) partners with community volunteers who perform regular sampling of more than 50 streams in the Marcellus and Utica Shale regions of upstate New York; samples are analyzed for parameters associated with HVHHF. Similar baseline data on regional groundwater comes from CSI's testing of private drinking water wells. Analytic results for groundwater (with permission) and surface water are made publicly available in an interactive, searchable database. Baseline concentrations of potential contaminants from shale gas operations are found to be low, suggesting that early community-based monitoring is an effective foundation for assessing later contamination due to fracking. PMID:23552652

  14. Dose-response and risk assessment of airborne hexavalent chromium and lung cancer mortality.

    PubMed

    Crump, Casey; Crump, Kenny; Hack, Eric; Luippold, Rose; Mundt, Kenneth; Liebig, Elizabeth; Panko, Julie; Paustenbach, Dennis; Proctor, Deborah

    2003-12-01

    This study evaluates the dose-response relationship for inhalation exposure to hexavalent chromium [Cr(VI)] and lung cancer mortality for workers of a chromate production facility, and provides estimates of the carcinogenic potency. The data were analyzed using relative risk and additive risk dose-response models implemented with both Poisson and Cox regression. Potential confounding by birth cohort and smoking prevalence were also assessed. Lifetime cumulative exposure and highest monthly exposure were the dose metrics evaluated. The estimated lifetime additional risk of lung cancer mortality associated with 45 years of occupational exposure to 1 microg/m3 Cr(VI) (occupational exposure unit risk) was 0.00205 (90%CI: 0.00134, 0.00291) for the relative risk model and 0.00216 (90%CI: 0.00143, 0.00302) for the additive risk model assuming a linear dose response for cumulative exposure with a five-year lag. Extrapolating these findings to a continuous (e.g., environmental) exposure scenario yielded an environmental unit risk of 0.00978 (90%CI: 0.00640, 0.0138) for the relative risk model [e.g., a cancer slope factor of 34 (mg/kg-day)-1] and 0.0125 (90%CI: 0.00833, 0.0175) for the additive risk model. The relative risk model is preferred because it is more consistent with the expected trend for lung cancer risk with age. Based on statistical tests for exposure-related trend, there was no statistically significant increased lung cancer risk below lifetime cumulative occupational exposures of 1.0 mg-yr/m3, and no excess risk for workers whose highest average monthly exposure did not exceed the current Permissible Exposure Limit (52 microg/m3). It is acknowledged that this study had limited power to detect increases at these low exposure levels. These cancer potency estimates are comparable to those developed by U.S. regulatory agencies and should be useful for assessing the potential cancer hazard associated with inhaled Cr(VI).

  15. A multi-level assessment methodology for determining the potential for groundwater contamination by pesticides.

    PubMed

    Crowe, A S; Booty, W G

    1995-05-01

    A multi-level pesticide assessment methodology has been developed to permit regulatory personnel to undertake a variety of assessments on the potential for pesticide used in agricultural areas to contaminate the groundwater regime at an increasingly detailed geographical scale of investigation. A multi-level approach accounts for a variety of assessment objectives and detail required in the assessment, the restrictions on the availability and accuracy of data, the time available to undertake the assessment, and the expertise of the decision maker. The level 1: regional scale is designed to prioritize districts having a potentially high risk for groundwater contamination from the application of a specific pesticide for a particular crop. The level 2: local scale is used to identify critical areas for groundwater contamination, at a soil polygon scale, within a district. A level 3: soil profile scale allows the user to evaluate specific factors influencing pesticide leaching and persistence, and to determine the extent and timing of leaching, through the simulation of the migration of a pesticide within a soil profile. Because of the scale of investigation, limited amount of data required, and qualitative nature of the assessment results, the level 1 and level 2 assessment are designed primarily for quick and broad guidance related to management practices. A level 3 assessment is more complex, requires considerably more data and expertise on the part of the user, and hence is designed to verify the potential for contamination identified during the level 1 or 2 assessment. The system combines environmental modelling, geographical information systems, extensive databases, data management systems, expert systems, and pesticide assessment models, to form an environmental information system for assessing the potential for pesticides to contaminate groundwater.

  16. Automatic roof plane detection and analysis in airborne lidar point clouds for solar potential assessment.

    PubMed

    Jochem, Andreas; Höfle, Bernhard; Rutzinger, Martin; Pfeifer, Norbert

    2009-01-01

    A relative height threshold is defined to separate potential roof points from the point cloud, followed by a segmentation of these points into homogeneous areas fulfilling the defined constraints of roof planes. The normal vector of each laser point is an excellent feature to decompose the point cloud into segments describing planar patches. An object-based error assessment is performed to determine the accuracy of the presented classification. It results in 94.4% completeness and 88.4% correctness. Once all roof planes are detected in the 3D point cloud, solar potential analysis is performed for each point. Shadowing effects of nearby objects are taken into account by calculating the horizon of each point within the point cloud. Effects of cloud cover are also considered by using data from a nearby meteorological station. As a result the annual sum of the direct and diffuse radiation for each roof plane is derived. The presented method uses the full 3D information for both feature extraction and solar potential analysis, which offers a number of new applications in fields where natural processes are influenced by the incoming solar radiation (e.g., evapotranspiration, distribution of permafrost). The presented method detected fully automatically a subset of 809 out of 1,071 roof planes where the arithmetic mean of the annual incoming solar radiation is more than 700 kWh/m(2).

  17. Mapping forest stand complexity for woodland caribou habitat assessment using multispectral airborne imagery

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Hu, B.; Woods, M.

    2014-11-01

    The decline of the woodland caribou population is a result of their habitat loss. To conserve the habitat of the woodland caribou and protect it from extinction, it is critical to accurately characterize and monitor its habitat. Conventionally, products derived from low to medium spatial resolution remote sensing data, such as land cover classification and vegetation indices are used for wildlife habitat assessment. These products fail to provide information on the structure complexities of forest canopies which reflect important characteristics of caribou's habitats. Recent studies have employed the LiDAR system (Light Detection And Ranging) to directly retrieve the three dimensional forest attributes. Although promising results have been achieved, the acquisition cost of LiDAR data is very high. In this study, utilizing the very high spatial resolution imagery in characterizing the structural development the of forest canopies was exploited. A stand based image texture analysis was performed to predict forest succession stages. The results were demonstrated to be consistent with those derived from LiDAR data.

  18. Airborne Multi-wavelength High Spectral Resolution Lidar for Process Studies and Assessment of Future Satellite Remote Sensing Concepts

    NASA Astrophysics Data System (ADS)

    Hostetler, C. A.; Ferrare, R. A.; Hair, J. W.; Cook, A. L.; Harper, D. B.; Mack, T. L.; Hare, R. J.; Cleckner, C. S.; Rogers, R.; Mueller, D.; Chemyakin, E.; Burton, S. P.; Obland, M. D.; Scarino, A. J.; Cairns, B.; Russell, P. B.; Redemann, J.; Shinozuka, Y.; Schmid, B.; Berg, L. K.; Fast, J. D.; Flynn, C. J.

    2012-12-01

    NASA Langley recently developed the world's first airborne multi-wavelength high spectral resolution lidar (HSRL). This lidar employs the HSRL technique at 355 and 532 nm to make independent, unambiguous retrievals of aerosol extinction and backscatter. It also employs the standard backscatter technique at 1064 nm and is polarization-sensitive at all three wavelengths. This instrument, dubbed HSRL-2 (the second-generation HSRL developed by NASA Langley), is a prototype for the lidar on NASA's planned Aerosols-Clouds-Ecosystems (ACE) mission. HSRL-2 completed its first science mission in July 2012, the Two-Column Aerosol Project (TCAP) conducted by the Department of Energy (DOE) in Hyannis, MA. TCAP presents an excellent opportunity to assess some of the remote sensing concepts planned for ACE: HSRL-2 was deployed on the Langley King Air aircraft with another ACE-relevant instrument, the NASA GISS Research Scanning Polarimeter (RSP), and flights were closely coordinated with the DOE's Gulfstream-1 aircraft, which deployed a variety of in situ aerosol and trace gas instruments and the new Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR). The DOE also deployed their Atmospheric Radiation Measurement Mobile Facility and their Mobile Aerosol Observing System at a ground site located on the northeastern coast of Cape Cod for this mission. In this presentation we focus on the capabilities, data products, and applications of the new HSRL-2 instrument. Data products include aerosol extinction, backscatter, depolarization, and optical depth; aerosol type identification; mixed layer depth; and range-resolved aerosol microphysical parameters (e.g., effective radius, index of refraction, single scatter albedo, and concentration). Applications include radiative closure studies, studies of aerosol direct and indirect effects, investigations of aerosol-cloud interactions, assessment of chemical transport models, air quality studies, present (e.g., CALIPSO

  19. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Riverton, Wyoming

    SciTech Connect

    Not Available

    1994-09-01

    This Risk Assessment evaluated potential impacts to public health or the environment caused by ground water contamination at the former uranium mill processing site. In the first phase of the U.S. Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project, the tailing and other contaminated material at this site were placed in a disposal cell near the Gas Hills Plant in 1990. The second phase of the UMTRA Project is to evaluate ground water contamination. This risk assessment is the first site-specific document to evaluate potential health and environmental risks for the Riverton site under the Ground Water Project; it will help determine whether remedial actions are needed for contaminated ground water at the site.

  20. Assessment of quantitative imaging of contaminant distributions in porous media

    NASA Astrophysics Data System (ADS)

    Catania, F.; Massabò, M.; Valle, M.; Bracco, G.; Paladino, O.

    2008-01-01

    In this article an experimental setup designed to assist in the characterization of complex solute transport problems in porous media is described. Glass beads representing the medium are confined in a 2-D transparent Perspex box and a water flow transports a fluorescent dye. Under suitable illumination, the dye emits visible light which is collected by a CCD camera. The image acquired by this non-invasive optical technique is processed to estimate the 2-dimensional distribution of tracer concentrations by using an appropriate calibration curve that links fluorescent intensity and solute concentration. Details about the dye choice and discussion about photobleaching are reported. An analysis of the experimental error on the concentration profile is also presented. A few recent results of a study on contaminant plume within a homogenous porous matrix constituted by glass beads having mean diameter of 1 mm or 2 mm shows the performance of constructed model.

  1. Contamination control and plume assessment of low-energy thrusters

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.

    1993-01-01

    Potential contamination of a spacecraft cryogenic surface by a xenon (Xe) ion generator was evaluated. The analysis involves the description of the plume exhausted from the generator with its relative component fluxes on the spacecraft surfaces, and verification of the conditions for condensation, adsorption, and sputtering at those locations. The data describing the plume fluxes and their effects on surfaces were obtained from two sources: the tests carried out with the Xe generator in a small vacuum chamber to indicate deposits and sputter on monitor slides; and the extensive tests with a mercury (Hg) ion thruster in a large vacuum chamber. The Hg thruster tests provided data on the neutrals, on low-energy ion fluxes, on high-energy ion fluxes, and on sputtered materials at several locations within the plume.

  2. Fungal Peptaibiotics: Assessing Potential Meteoritic Amino Acid Contamination

    NASA Technical Reports Server (NTRS)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; Bruckner, H.

    2010-01-01

    The presence of non-protein alpha-dialkyl-amino acids such as alpha-aminoisobutyric acid (alpha-A1B) and isovaline (Iva), which are relatively rare in the terrestrial biosphere, has long been used as an indication of the indigeneity of meteoritic amino acids, however, the discovery of alpha-AIB in peptides producers by a widespread group of filamentous fungi indicates the possibility of a terrestrial biotic source for the alpha-AIB observed in some meteorites. The alpha-AIB-containing peptides produced by these fungi are dubbed peptaibiotics. We measured the molecular distribution and stable carbon and nitrogen isotopic ratios for amino acids found in the total hydrolysates of four biologically synthesized peptaibiotics. We compared these aneasurenetts with those from the CM2 carbonaceous chondrite Murchison and from three Antarctic CR2 carbonaceous chondrites in order to understand the peptaibiotics as a potential source of meteoritic contamination.

  3. Laboratory and greenhouse assessment of phytoremediation of petroleum contaminated soils

    SciTech Connect

    Banks, M.K.; Schwab, A.P.; Wang, X.

    1996-12-31

    Phytoremediation of soils contaminated with petroleum and associated priority pollutants was evaluated in greenhouse and laboratory experiments. Mineralization of several PAHs was measured in rhizosphere soil, non-rhizosphere soil, and sterile soil amended with simulated root exudates. The least amount of mineralization was observed in sterile soil, but there were no differences among all other soils. Mineralization of 14 C-benzo[a]pyrene was determined in chambers to determine the effects of tall fescue on dissipation of this compound. After 180 days, the soils with fescue had more than twice the mineralization than soils without plants. In the soils with plants, evolution of 14CO2 from the soil was five times greater than from the plant biomass. These experiments demonstrate that the presence of plants is a necessary part of the phytoremediation process. There appears to be no residual rhizosphere effect, and the simple exudation of organic compounds does not mimic fully the presence of roots.

  4. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Canonsburg, Pennsylvania

    SciTech Connect

    Not Available

    1994-09-01

    This baseline risk assessment evaluates potential impacts to public health and the environment resulting from ground water contamination from past activities at the former uranium processing site in Canonsburg, Pennsylvania. The US Department of Energy Uranium Mill Tailings Remedial Action (UMTRA) Project has placed contaminated material from this site in an on-site disposal cell. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the UMTRA Ground Water Project. Currently, no domestic or drinking water well tap into contaminated ground water of the two distinct ground water units: the unconsolidated materials and the bedrock. Because there is no access, no current health or environmental risks are associated with the direct use of the contaminated ground water. However, humans and ecological organisms could be exposed to contaminated ground water if a domestic well were to be installed in the unconsolidated materials in that part of the site being considered for public use (Area C). The first step is evaluating ground water data collected from monitor wells at the site. For the Canonsburg site, this evaluation showed the contaminants in ground water exceeding background in the unconsolidated materials in Area C are ammonia, boron, calcium, manganese, molybdenum, potassium, strontium, and uranium.

  5. Characterization of heavy-metal-contaminated sediment by using unsupervised multivariate techniques and health risk assessment.

    PubMed

    Wang, Yeuh-Bin; Liu, Chen-Wuing; Wang, Sheng-Wei

    2015-03-01

    This study characterized the sediment quality of the severely contaminated Erjen River in Taiwan by using multivariate analysis methods-including factor analysis (FA), self-organizing maps (SOMs), and positive matrix factorization (PMF)-and health risk assessment. The SOMs classified the dataset with similar heavy-metal-contaminated sediment into five groups. FA extracted three major factors-traditional electroplating and metal-surface processing factor, nontraditional heavy-metal-industry factor, and natural geological factor-which accounted for 80.8% of the variance. The SOMs and FA revealed the heavy-metal-contaminated-sediment hotspots in the middle and upper reaches of the major tributary in the dry season. The hazardous index value for health risk via ingestion was 0.302. PMF further qualified the source apportionment, indicating that traditional electroplating and metal-surface-processing industries comprised 47% of the health risk posed by heavy-metal-contaminated sediment. Contaminants discharged from traditional electroplating and metal-surface-processing industries in the middle and upper reaches of the major tributary must be eliminated first to improve the sediment quality in Erjen River. The proposed assessment framework for heavy-metal-contaminated sediment can be applied to contaminated-sediment river sites in other regions.

  6. Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment.

    PubMed

    Niemeyer, Júlia Carina; Moreira-Santos, Matilde; Ribeiro, Rui; Rutgers, Michiel; Nogueira, Marco Antonio; da Silva, Eduardo Mendes; Sousa, José Paulo

    2015-01-01

    This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei), shoot length and plant biomass (Avena sativa, Brassica rapa). For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown) were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth). Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available chemical

  7. Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment

    PubMed Central

    Niemeyer, Júlia Carina; Moreira-Santos, Matilde; Ribeiro, Rui; Rutgers, Michiel; Nogueira, Marco Antonio; da Silva, Eduardo Mendes; Sousa, José Paulo

    2015-01-01

    This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei), shoot length and plant biomass (Avena sativa, Brassica rapa). For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown) were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth). Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available chemical

  8. Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment.

    PubMed

    Niemeyer, Júlia Carina; Moreira-Santos, Matilde; Ribeiro, Rui; Rutgers, Michiel; Nogueira, Marco Antonio; da Silva, Eduardo Mendes; Sousa, José Paulo

    2015-01-01

    This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei), shoot length and plant biomass (Avena sativa, Brassica rapa). For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown) were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth). Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available chemical

  9. Contamination assessment in microbiological sampling of the Eyreville core, Chesapeake Bay impact structure

    USGS Publications Warehouse

    Gronstal, A.L.; Voytek, M.A.; Kirshtein, J.D.; Von der, Heyde; Lowit, M.D.; Cockell, C.S.

    2009-01-01

    Knowledge of the deep subsurface biosphere is limited due to difficulties in recovering materials. Deep drilling projects provide access to the subsurface; however, contamination introduced during drilling poses a major obstacle in obtaining clean samples. To monitor contamination during the 2005 International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) deep drilling of the Chesapeake Bay impact structure, four methods were utilized. Fluorescent microspheres were used to mimic the ability of contaminant cells to enter samples through fractures in the core material during retrieval. Drilling mud was infused with a chemical tracer (Halon 1211) in order to monitor penetration of mud into cores. Pore water from samples was examined using excitation-emission matrix (EEM) fl uorescence spectroscopy to characterize dissolved organic carbon (DOC) present at various depths. DOC signatures at depth were compared to signatures from drilling mud in order to identify potential contamination. Finally, microbial contaminants present in drilling mud were identified through 16S ribosomal deoxyribonucleic acid (rDNA) clone libraries and compared to species cultured from core samples. Together, these methods allowed us to categorize the recovered core samples according to the likelihood of contamination. Twenty-two of the 47 subcores that were retrieved were free of contamination by all the methods used and were subsequently used for microbiological culture and culture-independent analysis. Our approach provides a comprehensive assessment of both particulate and dissolved contaminants that could be applied to any environment with low biomass. ?? 2009 The Geological Society of America.

  10. Toxicological assessment of aquatic ecosystems: application to watercraft contaminants in shallow water environments

    USGS Publications Warehouse

    Winger, P.V.; Kemmish, Michael J.

    2002-01-01

    Recreational boating and personal watercraft use have the potential to adversely impact shallow water systems through contaminant release and physical disturbance of bottom sediments. These nearshore areas are often already degraded by surface runoff, municipal and industrial effluents, and other anthropogenic activities. For proper management, information is needed on the level of contamination and environmental quality of these systems. A number of field and laboratory procedures can be used to provide this much needed information. Contaminants, such as metals, pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons, entering aquatic environments generally attach to particulate matter that eventually settles and becomes incorporated into the bottom sediments. Because bottom sediments serve as a sink and as a source for contaminants, environmental assessments generally focus on this matrix. While contaminant residues in sediments and sediment pore waters can reflect environmental quality, characteristics of sediment (redox potential, sediment/pore-water chemistry, acid volatile sulfides, percent organic matter, and sediment particle size) influence their bioavailability and make interpretation of environmental significance difficult. Comparisons of contaminant concentrations in pore water (interstitial water) and sediment with water quality criteria and sediment quality guidelines, respectively, can provide insight into potential biological effects. Laboratory bioaccumulation studies and residue concentrations in resident or caged biota also yield information on potential biological impacts. The usefulness of these measurements may increase as data are developed relating in-situ concentrations, tissue residue levels, and biological responses. Exposure of test organisms in situ or to field-collected sediment and pore water are additional procedures that can be used to assess the biological effects of contaminants. A battery of tests using multi

  11. Passive sampling in contaminated sediment assessment: building consensus to improve decision making.

    PubMed

    Parkerton, Thomas F; Maruya, Keith A

    2014-04-01

    Contaminated sediments pose an ongoing, pervasive, global challenge to environmental managers, because sediments can reflect a legacy of pollution that can impair the beneficial uses of water bodies. A formidable challenge in assessing the risks of contaminated sediments has been the elucidation and measurement of contaminant bioavailability, expressed as the freely dissolved concentration (Cfree ) in interstitial water, which serves as a surrogate measure of the substances' chemical activity. Recent advances in passive sampling methods (PSMs) enable Cfree of sediment-associated contaminants to be quantified at trace levels, thereby overcoming current limitations of predictive models. As a result, PSMs afford the opportunity for a paradigm shift from traditional practice that can effectively reduce uncertainty in risk assessment and bolster confidence in the science used to support management of contaminated sediments. This paper provides a brief overview of the 5 subsequent papers in this series that review literature on PSM use in sediments for both organic and metal(loid) contaminants, outline the technical rationale for using PSMs as a preferred basis for risk assessment over conventional chemical analyses, describe practical considerations for and uncertainties associated with laboratory and field deployment of PSMs, discuss management application of PSMs, including illustrative case studies in which PSMs have been used in decision making, and highlight future research and communication needs. PMID:24142815

  12. Guidance for treatment of variability and uncertainty in ecological risk assessments of contaminated sites

    SciTech Connect

    1998-06-01

    Uncertainty is a seemingly simple concept that has caused great confusion and conflict in the field of risk assessment. This report offers guidance for the analysis and presentation of variability and uncertainty in ecological risk assessments, an important issue in the remedial investigation and feasibility study processes. This report discusses concepts of probability in terms of variance and uncertainty, describes how these concepts differ in ecological risk assessment from human health risk assessment, and describes probabilistic aspects of specific ecological risk assessment techniques. The report ends with 17 points to consider in performing an uncertainty analysis for an ecological risk assessment of a contaminated site.

  13. A Bayesian belief network approach for assessing uncertainty in conceptual site models at contaminated sites.

    PubMed

    Thomsen, Nanna I; Binning, Philip J; McKnight, Ursula S; Tuxen, Nina; Bjerg, Poul L; Troldborg, Mads

    2016-05-01

    A key component in risk assessment of contaminated sites is in the formulation of a conceptual site model (CSM). A CSM is a simplified representation of reality and forms the basis for the mathematical modeling of contaminant fate and transport at the site. The CSM should therefore identify the most important site-specific features and processes that may affect the contaminant transport behavior at the site. However, the development of a CSM will always be associated with uncertainties due to limited data and lack of understanding of the site conditions. CSM uncertainty is often found to be a major source of model error and it should therefore be accounted for when evaluating uncertainties in risk assessments. We present a Bayesian belief network (BBN) approach for constructing CSMs and assessing their uncertainty at contaminated sites. BBNs are graphical probabilistic models that are effective for integrating quantitative and qualitative information, and thus can strengthen decisions when empirical data are lacking. The proposed BBN approach facilitates a systematic construction of multiple CSMs, and then determines the belief in each CSM using a variety of data types and/or expert opinion at different knowledge levels. The developed BBNs combine data from desktop studies and initial site investigations with expert opinion to assess which of the CSMs are more likely to reflect the actual site conditions. The method is demonstrated on a Danish field site, contaminated with chlorinated ethenes. Four different CSMs are developed by combining two contaminant source zone interpretations (presence or absence of a separate phase contamination) and two geological interpretations (fractured or unfractured clay till). The beliefs in each of the CSMs are assessed sequentially based on data from three investigation stages (a screening investigation, a more detailed investigation, and an expert consultation) to demonstrate that the belief can be updated as more information

  14. A Bayesian belief network approach for assessing uncertainty in conceptual site models at contaminated sites.

    PubMed

    Thomsen, Nanna I; Binning, Philip J; McKnight, Ursula S; Tuxen, Nina; Bjerg, Poul L; Troldborg, Mads

    2016-05-01

    A key component in risk assessment of contaminated sites is in the formulation of a conceptual site model (CSM). A CSM is a simplified representation of reality and forms the basis for the mathematical modeling of contaminant fate and transport at the site. The CSM should therefore identify the most important site-specific features and processes that may affect the contaminant transport behavior at the site. However, the development of a CSM will always be associated with uncertainties due to limited data and lack of understanding of the site conditions. CSM uncertainty is often found to be a major source of model error and it should therefore be accounted for when evaluating uncertainties in risk assessments. We present a Bayesian belief network (BBN) approach for constructing CSMs and assessing their uncertainty at contaminated sites. BBNs are graphical probabilistic models that are effective for integrating quantitative and qualitative information, and thus can strengthen decisions when empirical data are lacking. The proposed BBN approach facilitates a systematic construction of multiple CSMs, and then determines the belief in each CSM using a variety of data types and/or expert opinion at different knowledge levels. The developed BBNs combine data from desktop studies and initial site investigations with expert opinion to assess which of the CSMs are more likely to reflect the actual site conditions. The method is demonstrated on a Danish field site, contaminated with chlorinated ethenes. Four different CSMs are developed by combining two contaminant source zone interpretations (presence or absence of a separate phase contamination) and two geological interpretations (fractured or unfractured clay till). The beliefs in each of the CSMs are assessed sequentially based on data from three investigation stages (a screening investigation, a more detailed investigation, and an expert consultation) to demonstrate that the belief can be updated as more information

  15. A Bayesian belief network approach for assessing uncertainty in conceptual site models at contaminated sites

    NASA Astrophysics Data System (ADS)

    Thomsen, Nanna I.; Binning, Philip J.; McKnight, Ursula S.; Tuxen, Nina; Bjerg, Poul L.; Troldborg, Mads

    2016-05-01

    A key component in risk assessment of contaminated sites is in the formulation of a conceptual site model (CSM). A CSM is a simplified representation of reality and forms the basis for the mathematical modeling of contaminant fate and transport at the site. The CSM should therefore identify the most important site-specific features and processes that may affect the contaminant transport behavior at the site. However, the development of a CSM will always be associated with uncertainties due to limited data and lack of understanding of the site conditions. CSM uncertainty is often found to be a major source of model error and it should therefore be accounted for when evaluating uncertainties in risk assessments. We present a Bayesian belief network (BBN) approach for constructing CSMs and assessing their uncertainty at contaminated sites. BBNs are graphical probabilistic models that are effective for integrating quantitative and qualitative information, and thus can strengthen decisions when empirical data are lacking. The proposed BBN approach facilitates a systematic construction of multiple CSMs, and then determines the belief in each CSM using a variety of data types and/or expert opinion at different knowledge levels. The developed BBNs combine data from desktop studies and initial site investigations with expert opinion to assess which of the CSMs are more likely to reflect the actual site conditions. The method is demonstrated on a Danish field site, contaminated with chlorinated ethenes. Four different CSMs are developed by combining two contaminant source zone interpretations (presence or absence of a separate phase contamination) and two geological interpretations (fractured or unfractured clay till). The beliefs in each of the CSMs are assessed sequentially based on data from three investigation stages (a screening investigation, a more detailed investigation, and an expert consultation) to demonstrate that the belief can be updated as more information

  16. Assessment of urban tree growth from structure, nutrients and composition data derived from airborne lidar and imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Gu, H.; Townsend, P. A.; Singh, A.

    2014-12-01

    Urban forests provide important ecosystem services related to climate, nutrients, runoff and aesthetics. Assessment of variations in urban forest growth is critical to urban management and planning, as well as to identify responses to climate and other environmental changes. We estimated annual relative basal area increment by tree rings from 37 plots in Madison, Wisconsin and neighboring municipalities. We related relative basal area growth to variables of vegetation traits derived from remote sensing, including structure (aboveground biomass, diameter, height, basal area, crown width and crown length) from discrete-return airborne lidar, and biochemical variables (foliar nitrogen, carbon, lignin, cellulose, fiber and LMA), spectral indices (NDVI, NDWI, PRI, NDII etc.) and species composition from AVIRIS hyperspectral imagery. Variations in tree growth was mainly correlated with tree species composition (R2 = 0.29, RMSE = 0.004) with coniferous stands having a faster growth rate than broadleaf plots. Inclusion of stand basal area improved model prediction from R2 = 0.29 to 0.35, with RMSE = 0.003. Then, we assessed the growth by functional type, we found that foliar lignin concentration and the proportion of live coniferous trees explained 57% variance in the growth of conifer stands. In contrast, broadleaf forest growth was more strongly correlated with species composition and foliar carbon (R2 = 0.59, RMSE = 0.003). Finally, we compared the relative basal area growth by species. In our study area, red pine and white pine exhibited higher growth rates than other species, while white oak plots grew slowest. There is a significant negative relationship between tree height and the relative growth in red pine stands (r = -0.95), as well as a strong negative relationship between crown width and the relative growth in white pine stands (r = -0.87). Growth declines as trees grow taller and wider may partly be the result of reduced photosynthesis and water availability

  17. An assessment and quantitative uncertainty analysis of the health risks to workers exposed to chromium contaminated soils

    SciTech Connect

    Paustenbach, D.J.; Meyer, D.M.; Sheehan, P.J.; Lau, V. )

    1991-05-01

    Millions of tons of chromite-ore processing residue have been used as fill in various locations in Northern New Jersey and elsewhere in the United States. The primary toxicants in the residue are trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)). The hazard posed by Cr(III) is negligible due to its low acute and chronic toxicity. In contrast, Cr(VI) is considered a inhalation human carcinogen at high concentrations. Approximately 40 commercial and industrial properties in Northern New Jersey have been identified as containing chromite ore processing residue in the soil. The arithmetic mean and geometric mean concentrations of total chromium in soil were 977 and 359 mg/kg, respectively. The data were log-normal distributed. The arithmetic mean and geometric mean concentrations of Cr(VI) in surface soil were 37.6 and 3.1 mg/kg, respectively. The data could not be fit to a standard distribution, likely due to the large number of samples with concentrations below the method detection limit (65%). Dose was calculated for each exposure route using a Monte Carlo statistical simulation. Probability distributions of most exposure parameters were incorporated into the analyses to predict the range and probability of uptake for persons in the exposed population. The exposure parameter distributions included in this assessment are: the concentrations of Cr(VI) and total chromium in air and soil, fraction of the year when suspension of airborne soil particulates is likely to occur due to weather conditions, fraction of Cr(VI) in air which is respirable (less than 10 microns), soil loading rate on skin, occupational tenure, and body weight. The techniques used in this assessment are applicable for evaluating the human health risks posed by most industrial sites having contaminated soil.

  18. Dose assessment for management alternatives for NORM-contaminated equipment within the petroleum industry

    SciTech Connect

    Blunt, D.L.; Smith, K.P.

    1995-08-01

    The contamination of drilling and production equipment by naturally occurring radioactive material (NORM) is a growing concern for the petroleum industry and regulators. Large volumes of NORM-contaminated scrap metal are generated by the industry each year. The contamination generally occurs as surface contamination on the interior of water-handling equipment. The source of this contamination is accumulation of by-product wastes, in the form of scale and sludge contaminated with NORM that are generated by extraction processes. The primary radionuclides of concern in petroleum industry NORM-wastes are radium-226 (Ra-226), and radium-228 (Ra-228). These isotopes are members of the uranium-238 and thorium-232 decay series, respectively. The uranium and thorium isotopes, which are naturally present in the subsurface formations from which hydrocarbons are extracted, are largely immobile and remain in the subsurface. The more soluble radium can become mobilized in the formation water and be transported to the surface in the produced water waste stream. The radium either remains in solution or precipitates in scale or sludge deposits, depending on water salinity and on temperature and pressure phase changes. NORM-containing scale consists of radium that has coprecipitated with barium, calcium, or strontium sulfates, and sludge typically consists of radium-containing silicates and carbonates. This assessment is limited to the evaluation of potential radiological doses from management options that specifically involve recycle and reuse of contaminated metal. Doses from disposal of contaminated equipment are not addressed. Radiological doses were estimated for workers and the general public for equipment decontamination and smelting. Results of this assessment can be used to examine policy issues concerning the regulation and management of NORM-contaminated wastes generated by the petroleum industry.

  19. Assessment of bacterial contamination of drinking water provided to mice.

    PubMed

    Haist, Carrie; Cadillac, Joan; Dysko, Robert

    2004-11-01

    The objective of this study was to evaluate whether an 240-ml water bottle provided to individually housed mice would remain potable for a 2-week interval (based on absence of coliforms). The study used inbred C57BL/6 mice and CB6F1 x C3D2F1 hybrid mice. Test groups were assigned to minimize the variables of strain, caging type (non-ventilated static versus ventilated) and building location. A 3-cc sample of drinking water was removed aseptically from the bottles and vacuum-filtered using a 250-ml filter funnel with a 0.45-mum pore size. The membrane filter was removed using sterile forceps and placed on a blood agar plate for 10 min. The plate was streaked and incubated at 37 degrees C for 5 days. The plates were observed daily, and if growth had occurred, further testing was done to determine specific organisms. Of the 148 samples only 23 had any bacterial growth. Typical bacteria were unspeciated gram-positive bacilli and Staphylococcus, Micrococcus, Streptococcus, and Pantoea species. The absence of coliforms and low percentage of bacterial contamination suggest that drinking water will remain potable for 2 weeks when supplied to an individual mouse.

  20. Assessment of bacterial contamination of drinking water provided to mice.

    PubMed

    Haist, Carrie; Cadillac, Joan; Dysko, Robert

    2004-11-01

    The objective of this study was to evaluate whether an 240-ml water bottle provided to individually housed mice would remain potable for a 2-week interval (based on absence of coliforms). The study used inbred C57BL/6 mice and CB6F1 x C3D2F1 hybrid mice. Test groups were assigned to minimize the variables of strain, caging type (non-ventilated static versus ventilated) and building location. A 3-cc sample of drinking water was removed aseptically from the bottles and vacuum-filtered using a 250-ml filter funnel with a 0.45-mum pore size. The membrane filter was removed using sterile forceps and placed on a blood agar plate for 10 min. The plate was streaked and incubated at 37 degrees C for 5 days. The plates were observed daily, and if growth had occurred, further testing was done to determine specific organisms. Of the 148 samples only 23 had any bacterial growth. Typical bacteria were unspeciated gram-positive bacilli and Staphylococcus, Micrococcus, Streptococcus, and Pantoea species. The absence of coliforms and low percentage of bacterial contamination suggest that drinking water will remain potable for 2 weeks when supplied to an individual mouse. PMID:15636548

  1. International Space Station flights 1A/R-6A external contamination observations and surface assessment

    NASA Astrophysics Data System (ADS)

    Soares, Carlos E.; Mikatarian, Ronald R.; Scharf, Robert A.; Miles, Erica A.

    2002-09-01

    This paper documents International Space Station (ISS) external contamination observations and surface assessments covering Flights 1A/R through 6A. These observations are based on imaging from ISS missions, as active external contamination monitoring is not present in the configuration at this time. Imaging from ISS missions is a critical resource as it records the condition of ISS surfaces and helps identify visible signs of surface degradation. The observations are divided into three main sections; the first section covers the Functional Cargo Block (FGB - Russian Segment), the second section covers the Service Module (SM - Russian Segment), and the third section covers the U.S. Segment (Node 1 and Primary Mating Adapters 1 and 2). This distinction is important as materials selection, design and contamination control procedures differ between the FGB and Service Module on the Russian Segment and the U.S. Segment. Numerous observations of FGB self-contamination have been made through ISS imaging obtained during Shuttle flights. These observations were not surprising as external contamination studies conducted during the Shuttle-Mir (Phase I) Program showed extensive contamination induced by the Russian hardware. The impact of FGB induced contamination on ISS sensitive surfaces was mitigated due to FGB on-orbit time vacuum baking the Russian hardware prior to the deployment of ISS contamination sensitive hardware. Service Module impacts on ISS hardware were mitigated with a combination of changes in materials selection and on-orbit vacuum baking as there would be less on-orbit time before deployment of sensitive surfaces. While changes were made to materials selection, self-contamination observations have also been made on the Service Module. At this point, the U.S. Segment appears to be largely free of self-induced contamination. This confirms predictions made during the design and integration phase. Observed darkening and degradation of surfaces on the U

  2. A tiered assessment framework to evaluate human health risk of contaminated sediment.

    PubMed

    Greenfield, Ben K; Melwani, Aroon R; Bay, Steven M

    2015-07-01

    For sediment contaminated with bioaccumulative pollutants (e.g., PCBs and organochorine pesticides), human consumption of seafood that contain bioaccumulated sediment-derived contaminants is a well-established exposure pathway. Historically, regulation and management of this bioaccumulation pathway has focused on site-specific risk assessment. The state of California (United States) is supporting the development of a consistent and quantitative sediment assessment framework to aid in interpreting a narrative objective to protect human health. The conceptual basis of this framework focuses on 2 key questions: 1) do observed pollutant concentrations in seafood from a given site pose unacceptable health risks to human consumers? and 2) is sediment contamination at a site a significant contributor to seafood contamination? The first question is evaluated by interpreting seafood tissue concentrations at the site, based on health risk calculations. The second question is evaluated by interpreting site-specific sediment chemistry data using a food web bioaccumulation model. The assessment framework includes 3 tiers (screening assessment, site assessment, and refined site assessment), which enables the assessment to match variations in data availability, site complexity, and study objectives. The second and third tiers use a stochastic simulation approach, incorporating information on variability and uncertainty of key parameters, such as seafood contaminant concentration and consumption rate by humans. The framework incorporates site-specific values for sensitive parameters and statewide values for difficult to obtain or less sensitive parameters. The proposed approach advances risk assessment policy by incorporating local data into a consistent region-wide problem formulation, applying best available science in a streamlined fashion. PMID:25641876

  3. A tiered assessment framework to evaluate human health risk of contaminated sediment.

    PubMed

    Greenfield, Ben K; Melwani, Aroon R; Bay, Steven M

    2015-07-01

    For sediment contaminated with bioaccumulative pollutants (e.g., PCBs and organochorine pesticides), human consumption of seafood that contain bioaccumulated sediment-derived contaminants is a well-established exposure pathway. Historically, regulation and management of this bioaccumulation pathway has focused on site-specific risk assessment. The state of California (United States) is supporting the development of a consistent and quantitative sediment assessment framework to aid in interpreting a narrative objective to protect human health. The conceptual basis of this framework focuses on 2 key questions: 1) do observed pollutant concentrations in seafood from a given site pose unacceptable health risks to human consumers? and 2) is sediment contamination at a site a significant contributor to seafood contamination? The first question is evaluated by interpreting seafood tissue concentrations at the site, based on health risk calculations. The second question is evaluated by interpreting site-specific sediment chemistry data using a food web bioaccumulation model. The assessment framework includes 3 tiers (screening assessment, site assessment, and refined site assessment), which enables the assessment to match variations in data availability, site complexity, and study objectives. The second and third tiers use a stochastic simulation approach, incorporating information on variability and uncertainty of key parameters, such as seafood contaminant concentration and consumption rate by humans. The framework incorporates site-specific values for sensitive parameters and statewide values for difficult to obtain or less sensitive parameters. The proposed approach advances risk assessment policy by incorporating local data into a consistent region-wide problem formulation, applying best available science in a streamlined fashion.

  4. Riverland ERA maintenance pad site diesel contamination risk assessment

    SciTech Connect

    Valcich, P.J.

    1993-12-02

    The maintenance pad site consists of a concrete pad and underlying soils, approximately 15 by 46 m in area, and a drainage ditch with dimensions of 2.4 by 91 m. The ditch is located approximately 60 m from the concrete pad and is oriented parallel to the pads long axis. The facility was built in 1943, at which time the concrete pad was the floor of a maintenance shed for railroad activities. In 1955, use of the facility as a maintenance shed was discontinued. Between 1955 and 1957, the facility was used as a radioactivity decontamination area for railroad cars; acetone-soaked rags were used to remove surface contamination from the cars. The concrete pad was washed down with a mixture of water and diesel fuel, which was then flushed via clay pipe to the drainage ditch. In 1963, the maintenance shed was torn down and the concrete pad covered with approximately one-half meter of fill. The concrete pad was re-exposed in 1993. The site was sampled for Toxicity Characteristic Leachate Procedure (TCLP) metals, volatile, and semi-volatile compounds, as well as for extractable fuel hydrocarbons. A total of 17 samples were collected from surface concrete, soil beneath surface concrete, and ditch soil. One concrete sample and one ditch soil sample were split. The ditch soil sample was also duplicated. The relative percent difference (RPD) in extractable hydrocarbons of the two split samples, one from concrete and one from ditch soil are, respectively, 52% and 186%. The RPD for the duplicate sample, taken from the same ditch soil sample from which one of the splits was taken, is 39%.

  5. Field studies in estuarine ecosystems: A review of approaches for assessing contaminant effects

    SciTech Connect

    Clark, J.R.

    1989-01-01

    The types of data obtained in field studies must correspond to data used for risk assessment in order to verify approaches to predicting contaminant fate and effects in estuarine systems. Survival of caged test animals at field test sites provides field data for direct comparison with laboratory toxicity test results. Coupling survival and other effects data from caged-animal studies with assessments of stocks and dynamics of populations of the same or a related species at the field site allows extrapolation from simple laboratory and field test results to more complex and ecologically significant interpretations. The paper presents examples of various approaches to contaminant problems in estuaries.

  6. Methodology for back-contamination risk assessment for a Mars sample return mission

    NASA Technical Reports Server (NTRS)

    Merkhofer, M. W.; Quinn, D. J.

    1977-01-01

    The risk of back-contamination from Mars Surface Sample Return (MSSR) missions is assessed. The methodology is designed to provide an assessment of the probability that a given mission design and strategy will result in accidental release of Martian organisms acquired as a result of MSSR. This is accomplished through the construction of risk models describing the mission risk elements and their impact on back-contamination probability. A conceptual framework is presented for using the risk model to evaluate mission design decisions that require a trade-off between science and planetary protection considerations.

  7. Coupling geochemical, mineralogical and microbiological approaches to assess the health of contaminated soil around the Almalyk mining and smelter complex, Uzbekistan.

    PubMed

    Shukurov, Nosir; Kodirov, Obidjon; Peitzsch, Mirko; Kersten, Michael; Pen-Mouratov, Stanislav; Steinberger, Yosef

    2014-04-01

    This study describes the impact of airborne pollution resulting from mining and smelting activities on the soils of the Almalyk mining and industrial area (NE Uzbekistan). Samples were collected along a transect downwind of the industrial area. Enriched contents of some metals were found in the upper soil layers near the metallurgical complex (Zn≤3010 mg kg(-1), Pb≤630 mg kg(-1), Cd≤30 mg kg(-1)) which suggests that these metals were derived from local stack emissions. The morphology and internal microstructure of metal-bearing spherical particles found in the heavy mineral fraction suggest that these particles were probably a result of inefficient flue gas cleaning technique of the smelter. The highest metal concentrations were found also in soil solutions and exchangeable solid fractions from the first three locations, and decreased with increasing distance from the pollution source along transect. Thermodynamic equilibrium calculations suggest that the mobile metal pool in the contaminated soil is mainly controlled by dissolution of metal carbonates formed as weathering product of the metalliferous particles. The health of the microbiological soil ecosystem was assessed by measurements of basal respiration, nematode abundance, biomass-related C and N content, and microbial metabolic quotient qCO2. Significant correlations were found between the dissolved metal content and the microbiological health parameters, a negative one for Cmic/Corg ratio, and a positive one for qCO2. A negative correlation was found between the amount of nematodes and the metal contents suggesting that the contaminated soil has significant impact on the functioning of the microbiological community. A better understanding of the spatial variations in the whole ecosystem functioning due to airborne impact could be very useful for establishing suitable land use and best management practices for the polluted areas.

  8. Risk assessment for chemical pickling of metals contaminated by radioactive materials.

    PubMed

    Donzella, A; Formisano, P; Giroletti, E; Zenoni, A

    2007-01-01

    In recent years, many cases of contamination of metal scraps by unwanted radioactive materials have occurred. Moreover, international organisations are evaluating the possibility to re-use or to recycle metals coming from nuclear power plants. The metal recycling industry has started to worry about radiation exposure of workers that could be in contact with contaminated metals during each manufacturing phase. Risks are strongly dependent on the radiation source features. The aim of this study is to perform risk assessment for workers involved in chemical pickling of steel coils. Monte Carlo simulations have been performed, using the MCNP package and considering coils contaminated with (60)Co, (137)Cs, (241)Am and (226)Ra. Under the most conservative conditions (coil contaminated with 1.0 kBq g(-1) of (60)Co), the dose assessment results lower than the European dose limit for the population (1 mSv y(-1)), considering a maximum number of 10 contaminated coils handled per year. The only exception concerns the case of (241)Am, for which internal contamination could be non- negligible and should be verified in the specific cases. In every case, radiation exposure risk for people standing at 50 m from the coil is widely <1 mSv y(-1).

  9. Risk assessment for chemical pickling of metals contaminated by radioactive materials.

    PubMed

    Donzella, A; Formisano, P; Giroletti, E; Zenoni, A

    2007-01-01

    In recent years, many cases of contamination of metal scraps by unwanted radioactive materials have occurred. Moreover, international organisations are evaluating the possibility to re-use or to recycle metals coming from nuclear power plants. The metal recycling industry has started to worry about radiation exposure of workers that could be in contact with contaminated metals during each manufacturing phase. Risks are strongly dependent on the radiation source features. The aim of this study is to perform risk assessment for workers involved in chemical pickling of steel coils. Monte Carlo simulations have been performed, using the MCNP package and considering coils contaminated with (60)Co, (137)Cs, (241)Am and (226)Ra. Under the most conservative conditions (coil contaminated with 1.0 kBq g(-1) of (60)Co), the dose assessment results lower than the European dose limit for the population (1 mSv y(-1)), considering a maximum number of 10 contaminated coils handled per year. The only exception concerns the case of (241)Am, for which internal contamination could be non- negligible and should be verified in the specific cases. In every case, radiation exposure risk for people standing at 50 m from the coil is widely <1 mSv y(-1). PMID:16849378

  10. Consumer product in vitro digestion model: Bioaccessibility of contaminants and its application in risk assessment.

    PubMed

    Brandon, Esther F A; Oomen, Agnes G; Rompelberg, Cathy J M; Versantvoort, Carolien H M; van Engelen, Jacqueline G M; Sips, Adrienne J A M

    2006-03-01

    This paper describes the applicability of in vitro digestion models as a tool for consumer products in (ad hoc) risk assessment. In current risk assessment, oral bioavailability from a specific product is considered to be equal to bioavailability found in toxicity studies in which contaminants are usually ingested via liquids or food matrices. To become bioavailable, contaminants must first be released from the product during the digestion process (i.e. become bioaccessible). Contaminants in consumer products may be less bioaccessible than contaminants in liquid or food. Therefore, the actual risk after oral exposure could be overestimated. This paper describes the applicability of a simple, reliable, fast and relatively inexpensive in vitro method for determining the bioaccessibility of a contaminant from a consumer product. Different models, representing sucking and/or swallowing were developed. The experimental design of each model can be adjusted to the appropriate exposure scenarios as determined by the risk assessor. Several contaminated consumer products were tested in the various models. Although relevant in vivo data are scare, we succeeded to preliminary validate the model for one case. This case showed good correlation and never underestimated the bioavailability. However, validation check needs to be continued.

  11. Assessment of the contamination of marine fauna by chlordecone in Guadeloupe and Martinique (Lesser Antilles).

    PubMed

    Dromard, Charlotte R; Bodiguel, Xavier; Lemoine, Soazig; Bouchon-Navaro, Yolande; Reynal, Lionel; Thouard, Emmanuel; Bouchon, Claude

    2016-01-01

    Chlordecone is an organochlorine pesticide, used in the Lesser Antilles from 1972 to 1993 to fight against a banana weevil. That molecule is very persistent in the natural environment and ends up in the sea with runoff waters. From 2003 to 2013, seven campaigns of samplings have been conducted to evaluate the level of contamination of fish, crustaceans, and mollusks. The present study is the first assessment and the first comparison of the concentrations of chlordecone between marine areas, taxonomic groups, and ecological factors like trophic groups or preferential habitat of fish species. The four most contaminated marine areas are located downstream the contaminated rivers and banana plantations. Crustaceans seemed to be more sensitive to the contamination than fish or mollusks. Finally, when comparing contamination of fish according to their ecology, we found that fish usually living at the border of mangrove and presenting detritivores-omnivores diets were the most contaminated by chlordecone. These results are particularly useful to protect the health of the local population by controlling the fishing and the commercialization of seafood products, potentially contaminated by chlordecone. PMID:25994274

  12. Assessment of the contamination of marine fauna by chlordecone in Guadeloupe and Martinique (Lesser Antilles).

    PubMed

    Dromard, Charlotte R; Bodiguel, Xavier; Lemoine, Soazig; Bouchon-Navaro, Yolande; Reynal, Lionel; Thouard, Emmanuel; Bouchon, Claude

    2016-01-01

    Chlordecone is an organochlorine pesticide, used in the Lesser Antilles from 1972 to 1993 to fight against a banana weevil. That molecule is very persistent in the natural environment and ends up in the sea with runoff waters. From 2003 to 2013, seven campaigns of samplings have been conducted to evaluate the level of contamination of fish, crustaceans, and mollusks. The present study is the first assessment and the first comparison of the concentrations of chlordecone between marine areas, taxonomic groups, and ecological factors like trophic groups or preferential habitat of fish species. The four most contaminated marine areas are located downstream the contaminated rivers and banana plantations. Crustaceans seemed to be more sensitive to the contamination than fish or mollusks. Finally, when comparing contamination of fish according to their ecology, we found that fish usually living at the border of mangrove and presenting detritivores-omnivores diets were the most contaminated by chlordecone. These results are particularly useful to protect the health of the local population by controlling the fishing and the commercialization of seafood products, potentially contaminated by chlordecone.

  13. Identification and assessment of trace contaminants associated with oil and gas pipelines abandoned in place

    SciTech Connect

    Thorne, W.E.R.; Basso, A.C.; Dhol, S.K.

    1996-12-31

    As more Alberta oil and gas fields become depleted, attention is being given to development of economically and environmentally sound abandonment procedures. The objective of this study was to identify and assess residual internal and external contaminants associated with abandoned pipelines, particularly those to be abandoned in place. Circumstances which might increase the risk of contaminant release, and other issues relating to residual pipeline contaminants, were also identified. It was found that there are thousands of different substances which could potentially be associated with abandoned pipelines. A wide range in the potential quantities of residual contaminants was also found. Of the issues identified, the effectiveness of pipeline pigging and cleaning procedures prior to abandonment was the most critical determinant of the potential quantities of residual contaminants. However, a number of trace contaminants, such as PCBs (Polychlorinated Biphenyls) and NORMs (Naturally Occurring Radioactive Materials) may remain after thorough cleaning. A brief review of the legislation and regulations from a number of jurisdictions shows that pipeline abandonment has only recently become an issue of concern. Regulations specific to abandonment are lacking, and more general regulations and guidelines are being applied on a contaminant-specific basis, or in terms of waste disposal requirements.

  14. Establishing indices for groundwater contamination risk assessment in the vicinity of hazardous waste landfills in China.

    PubMed

    Li, Ying; Li, Jinhui; Chen, Shusheng; Diao, Weihua

    2012-06-01

    Groundwater contamination by leachate is the most damaging environmental impact over the entire life of a hazardous waste landfill (HWL). With the number of HWL facilities in China rapidly increasing, and considering the poor status of environmental risk management, it is imperative that effective environmental risk management methods be implemented. A risk assessment indices system for HWL groundwater contamination is here proposed, which can simplify the risk assessment procedure and make it more user-friendly. The assessment framework and indices were drawn from five aspects: source term, underground media, leachate properties, risk receptors and landfill management quality, and a risk assessment indices system consisting of 38 cardinal indicators was established. Comparison with multimedia models revealed that the proposed indices system was integrated and quantitative, that input data for it could be easily collected, and that it could be widely used for environmental risk assessment (ERA) in China.

  15. Assessment of diesel contamination in groundwater using electromagnetic induction geophysical techniques.

    PubMed

    Jin, Song; Fallgren, Paul; Cooper, Jeffrey; Morris, Jeffrey; Urynowicz, Michael

    2008-05-01

    Determining hydrocarbon plumes in groundwater is typically accomplished through the installation of extensive monitoring wells. Issues of scale and site heterogeneities tend to introduce errors in delineating the extent of contamination and environmental impact. In this study, electromagnetic induction survey was investigated as an alternative technique for mapping petroleum contaminants in the subsurface. The surveys were conducted at a coal mining site near Gillette, Wyoming, using the EM34-XL ground conductivity meter. Data from this survey were validated with known concentrations of diesel compounds detected in groundwater from the study site. Groundwater data correlated well with the electromagnetic survey data, which was used to generate a site model to identify subsurface diesel plumes. To our knowledge, this is one of the first studies to use electromagnetic survey techniques for mapping hydrocarbon contamination in groundwater. Results from this study indicate that this geophysical technique can be an effective tool for assessing subsurface petroleum hydrocarbon sources and plumes at contaminated sites.

  16. Assessment of diesel contamination in groundwater using electromagnetic induction geophysical techniques

    SciTech Connect

    Jin, S.; Fallgren, P.; Cooper, J.; Morris, J; . Urynowicz, M.

    2008-07-01

    Determining hydrocarbon plumes in groundwater is typically accomplished through the installation of extensive monitoring wells. Issues of scale and site heterogeneities tend to introduce errors in delineating the extent of contamination and environmental impact. In this study, electromagnetic induction survey was investigated as an alternative technique for mapping petroleum contaminants in the subsurface. The surveys were conducted at a coal mining site near Gillette, Wyoming, using the EM34-XL ground conductivity meter. Data from this survey were validated with known concentrations of diesel compounds detected in groundwater from the study site. Groundwater data correlated well with the electromagnetic survey data, which was used to generate a site model to identify subsurface diesel plumes. To our knowledge, this is one of the first studies to use electromagnetic survey techniques for mapping hydrocarbon contamination in groundwater. Results from this study indicate that this geophysical technique can be an effective tool for assessing subsurface petroleum hydrocarbon sources and plumes at contaminated sites.

  17. Risk assessment of groundwater contamination: a multilevel fuzzy comprehensive evaluation approach based on DRASTIC model.

    PubMed

    Zhang, Qiuwen; Yang, Xiaohong; Zhang, Yan; Zhong, Ming

    2013-01-01

    Groundwater contamination is a serious threat to water supply. Risk assessment of groundwater contamination is an effective way to protect the safety of groundwater resource. Groundwater is a complex and fuzzy system with many uncertainties, which is impacted by different geological and hydrological factors. In order to deal with the uncertainty in the risk assessment of groundwater contamination, we propose an approach with analysis hierarchy process and fuzzy comprehensive evaluation integrated together. Firstly, the risk factors of groundwater contamination are identified by the sources-pathway-receptor-consequence method, and a corresponding index system of risk assessment based on DRASTIC model is established. Due to the complexity in the process of transitions between the possible pollution risks and the uncertainties of factors, the method of analysis hierarchy process is applied to determine the weights of each factor, and the fuzzy sets theory is adopted to calculate the membership degrees of each factor. Finally, a case study is presented to illustrate and test this methodology. It is concluded that the proposed approach integrates the advantages of both analysis hierarchy process and fuzzy comprehensive evaluation, which provides a more flexible and reliable way to deal with the linguistic uncertainty and mechanism uncertainty in groundwater contamination without losing important information.

  18. Assessing exposures and risks in heterogeneously contaminated areas: A simulation approach

    SciTech Connect

    Fingleton, D.J.; MacDonell, M.M.; Haroun, L.A. ); Oezkaynak, H.; Butler, D.A.; Jianping Xue )

    1991-01-01

    The US Department of Energy (DOE) is responsible for cleanup activities at a number of facilities under its Environmental Restoration and Waste Management Program. The major goals of this program are to eliminate potential hazards to human health and the environment that are associated with contamination of these sites and, to the extent possible, make surplus real property available for other uses. The assessment of potential baseline health risks and ecological impacts associated with a contaminated site is an important component of the remedial investigation/feasibility study (RI/FS) process required at all Superfund sites. The purpose of this paper is to describe one phase of the baseline assessment, i.e., the characterization of human health risks associated with exposure to chemical contaminants in air and on interior building surfaces at a contaminated site. The model combines data on human activity patterns in a particular microenvironment within a building with contaminant concentrations in that microenvironment to calculate personal exposure profiles and risks within the building. The results of the building assessment are presented as probability distributions functions and cumulative distribution functions, which show the variability and uncertainty in the risk estimates. 23 refs., 2 figs., 1 tab.

  19. Toxicity assessment for petroleum-contaminated soil using terrestrial invertebrates and plant bioassays.

    PubMed

    Hentati, Olfa; Lachhab, Radhia; Ayadi, Mariem; Ksibi, Mohamed

    2013-04-01

    The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC50 of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils. PMID:22773148

  20. Risk Assessment of Groundwater Contamination: A Multilevel Fuzzy Comprehensive Evaluation Approach Based on DRASTIC Model

    PubMed Central

    Zhang, Yan; Zhong, Ming

    2013-01-01

    Groundwater contamination is a serious threat to water supply. Risk assessment of groundwater contamination is an effective way to protect the safety of groundwater resource. Groundwater is a complex and fuzzy system with many uncertainties, which is impacted by different geological and hydrological factors. In order to deal with the uncertainty in the risk assessment of groundwater contamination, we propose an approach with analysis hierarchy process and fuzzy comprehensive evaluation integrated together. Firstly, the risk factors of groundwater contamination are identified by the sources-pathway-receptor-consequence method, and a corresponding index system of risk assessment based on DRASTIC model is established. Due to the complexity in the process of transitions between the possible pollution risks and the uncertainties of factors, the method of analysis hierarchy process is applied to determine the weights of each factor, and the fuzzy sets theory is adopted to calculate the membership degrees of each factor. Finally, a case study is presented to illustrate and test this methodology. It is concluded that the proposed approach integrates the advantages of both analysis hierarchy process and fuzzy comprehensive evaluation, which provides a more flexible and reliable way to deal with the linguistic uncertainty and mechanism uncertainty in groundwater contamination without losing important information. PMID:24453883

  1. Assessment of contaminant fate in catchments using a novel integrated hydrobiogeochemical-multimedia fate model.

    PubMed

    Nizzetto, Luca; Butterfield, Dan; Futter, Martyn; Lin, Yan; Allan, Ian; Larssen, Thorjørn

    2016-02-15

    Models for pollution exposure assessment typically adopt an overly simplistic representation of geography, climate and biogeochemical processes. This strategy is unsatisfactory when high temporal resolution simulations for sub-regional spatial domains are performed, in which parameters defining scenarios can vary interdependently in space and time. This is, for example, the case when assessing the influence of biogeochemical processing on contaminant fate. Here we present INCA-Contaminants, the Integrated Catchments model for Contaminants; a new model that simultaneously and realistically solves mass balances of water, carbon, sediments and contaminants in the soil-stream-sediment system of catchments and their river networks as a function of climate, land use/management and contaminant properties. When forced with realistic climate and contaminant input data, the model was able to predict polychlorinated biphenyls (PCBs) concentrations in multiple segments of a river network in a complex landscape. We analyzed model output sensitivity to a number of hydro-biogeochemical parameters. The rate of soil organic matter mineralization was the most sensitive parameter controlling PCBs levels in river water, supporting the hypothesis that organic matter turnover rates will influence re-mobilization of previously deposited PCBs which had accumulated in soil organic matrix. The model was also used to project the long term fate of PCB 101 under two climate scenarios. Catchment diffuse run-off and riverine transport were the major pathways of contaminant re-mobilization. Simulations show that during the next decade the investigated boreal catchment will shift from being a net atmospheric PCB sink to a net source for air and water, with future climate perturbation having little influence on this trend. Our results highlight the importance of using credible hydro-biogeochemical simulations when modeling the fate of hydrophobic contaminants. PMID:26674684

  2. Assessing nitrate contamination and its potential health risk to Kinmen residents.

    PubMed

    Liu, Chen-Wuing; Lin, Chun-Nan; Jang, Cheng-Shin; Ling, Min-Pei; Tsai, Jeng-Wei

    2011-10-01

    Kinmen is located in the southwest of Mainland China. Groundwater supplies 50% of the domestic water use on the island. Residents of Kinmen drink groundwater over the long term because surface water resources are limited. Nitrate-N pollution is found and distributed primarily in the western part of groundwater aquifer whereas saline groundwater is distributed to the northeastern Kinmen. This work applied the DRASTIC model to construct the vulnerability map of Kinmen groundwater. MT3D was then used to evaluate the contamination potential of nitrate-N. The health risk associated with the ingestion of nitrate-N contaminated groundwater is also assessed. The results from DRASTIC model showed that the upland crop and grass land have high contamination potential, whereas the forest, reservoir and housing land have low contamination potential. The calibrated MT3D model inversely determined the high strength sources (0.09-2.74 kg/m(2)/year) of nitrate contaminant located in the west to the north west area and required 2-5 years travel time to reach the monitoring wells. Simulated results of MT3D also showed that both the continuous and instantaneous contaminant sources of nitrate-N release may cause serious to moderate nitrate contamination in the western Kinmen and jeopardize the domestic use of groundwater. The chronic health hazard quotient (HQ) associated with the potential non-carcinogenic risk of drinking nitrate-N contaminated groundwater showed that the assessed 95th percentile of HQ is 2.74, indicating that exposure to waterborne nitrate poses a potential non-cancer risk to the residents of the island. Corrective measures, including protecting groundwater recharge zones and reducing the number of agricultural and non-agricultural nitrogen sources that enters the aquifer, should be implemented especially in the western part of Kinmen to assure a sustainable use of groundwater resources.

  3. Multimedia contaminant environmental exposure assessment methodology as applied to Los Alamos, New Mexico

    SciTech Connect

    Whelan, G.; Thompson, F.L.; Yabusaki, S.B.

    1983-02-01

    The MCEA (Multimedia Contaminant Environmental Exposure Assessment) methodology assesses exposures to air, water, soil, and plants from contaminants released into the environment by simulating dominant mechanisms of contaminant migration and fate. The methodology encompasses five different pathways (i.e., atmospheric, terrestrial, overland, subsurface, and surface water) and combines them into a highly flexible tool. The flexibility of the MCEA methodology is demonstrated by encompassing two of the pathways (i.e., overland and surface water) into an effective tool for simulating the migration and fate of radionuclides released into the Los Alamos, New Mexico region. The study revealed that: (a) the /sup 239/Pu inventory in lower Los Alamos Canyon increased by approximately 1.1 times for the 50-y flood event; (b) the average contaminant /sup 239/Pu concentrations (i.e., weighted according to the depth of the respective bed layer) in lower Los Alamos Canyon for the 50-y flood event decreased by 5.4%; (c) approx. 27% of the total /sup 239/Pu contamination resuspended from the entire bed (based on the assumed cross sections) for the 50-y flood event originated from lower Pueblo Canyon; (d) an increase in the /sup 239/Pu contamination of the bed followed the general deposition patterns experienced by the sediment in Pueblo-lower Los Alamos Canyon; likewise, a decrease in the /sup 239/Pu contamination of the bed followed general sediment resuspension patterns in the canyon; (e) 55% of the /sup 239/Pu reaching the San Ildefonso Pueblo in lower Los Alamos Canyon originated from lower Los Alamos Canyon; and (f) 56% of the /sup 239/Pu contamination reaching the San Ildefonso Pueblo in lower Los Alamos Canyon was carried through towards the Rio Grande. 47 references, 41 figures, 29 tables.

  4. Waste Area Grouping 2 Remedial Investigation Phase 1 Seep Task data report: Contaminant source area assessment

    SciTech Connect

    Hicks, D.S.

    1996-03-01

    This report presents the findings of the Waste Area Grouping (WAG) 2, Phase 1 Remedial Investigation (RI) Seep Task efforts during 1993 and 1994 at Oak Ridge National Laboratory (ORNL). The results presented here follow results form the first year of sampling, 1992, which are contained in the Phase 1 RI report for WAG 2 (DOE 1995a). The WAG 2 Seep Task efforts focused on contaminants in seeps, tributaries, and main streams within the White Oak Creek (WOC) watershed. This report is designed primarily as a reference for contaminants and a resource for guiding remedial decisions. Additional in-depth assessments of the Seep Task data may provide clearer understandings of contaminant transport from the different source areas in the WOC watershed. WAG 2 consists of WOC and its tributaries downstream of the ORNL main plant area, White Oak Lake, the White Oak Creek Embayment of the Clinch River, and the associated flood plains and subsurface environment. The WOC watershed encompasses ORNL and associated WAGs. WAG 2 acts as an integrator for contaminant releases from the contaminated sites at ORNL and as the conduit transporting contaminants to the Clinch River. The main objectives of the Seep Task were to identify and characterize seeps, tributaries and source areas that are responsible for the contaminant releases to the main streams in WAG 2 and to quantify their input to the total contaminant release from the watershed at White Oak Dam (WOD). Efforts focused on {sup 90}Sr, {sup 3}H, and {sup 137}Cs because these contaminants pose the greatest potential human health risk from water ingestion at WOD. Bimonthly sampling was conducted throughout the WOC watershed beginning in March 1993 and ending in August 1994. Samples were also collected for metals, anions, alkalinity, organics, and other radionuclides.

  5. Levels and risk assessment of chemical contaminants in byproducts for animal feed in Denmark.

    PubMed

    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. PMID:25190554

  6. Levels and risk assessment of chemical contaminants in byproducts for animal feed in Denmark.

    PubMed

    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.

  7. Opportunities and challenges of integrating ecological restoration into assessment and management of contaminated ecosystems.

    PubMed

    Hull, Ruth N; Luoma, Samuel N; Bayne, Bruce A; Iliff, John; Larkin, Daniel J; Paschke, Mark W; Victor, Sasha L; Ward, Sara E

    2016-04-01

    Ecosystem restoration planning near the beginning of the site assessment and management process ("early integration") involves consideration of restoration goals from the outset in developing solutions for contaminated ecosystems. There are limitations to integration that stem from institutional barriers, few successful precedents, and limited availability of guidance. Challenges occur in integrating expertise from various disciplines and multiple, sometimes divergent interests and goals. The more complex process can result in timing, capacity, communication, and collaboration challenges. On the other hand, integrating the 2 approaches presents new and creative opportunities. For example, integration allows early planning for expanding ecosystem services on or near contaminated lands or waters that might otherwise have been unaddressed by remediation alone. Integrated plans can explicitly pursue ecosystem services that have market value, which can add to funds for long-term monitoring and management. Early integration presents opportunities for improved and productive collaboration and coordination between ecosystem restoration and contaminant assessment and management. Examples exist where early integration facilitates liability resolution and generates positive public relations. Restoration planning and implementation before the completion of the contaminated site assessment, remediation, or management process ("early restoration") can facilitate coordination with offsite restoration options and a regional approach to restoration of contaminated environments. Integration of performance monitoring, for both remedial and restoration actions, can save resources and expand the interpretive power of results. Early integration may aid experimentation, which may be more feasible on contaminated lands than in many other situations. The potential application of concepts and tools from adaptive management is discussed as a way of avoiding pitfalls and achieving benefits in

  8. Opportunities and challenges of integrating ecological restoration into assessment and management of contaminated ecosystems.

    PubMed

    Hull, Ruth N; Luoma, Samuel N; Bayne, Bruce A; Iliff, John; Larkin, Daniel J; Paschke, Mark W; Victor, Sasha L; Ward, Sara E

    2016-04-01

    Ecosystem restoration planning near the beginning of the site assessment and management process ("early integration") involves consideration of restoration goals from the outset in developing solutions for contaminated ecosystems. There are limitations to integration that stem from institutional barriers, few successful precedents, and limited availability of guidance. Challenges occur in integrating expertise from various disciplines and multiple, sometimes divergent interests and goals. The more complex process can result in timing, capacity, communication, and collaboration challenges. On the other hand, integrating the 2 approaches presents new and creative opportunities. For example, integration allows early planning for expanding ecosystem services on or near contaminated lands or waters that might otherwise have been unaddressed by remediation alone. Integrated plans can explicitly pursue ecosystem services that have market value, which can add to funds for long-term monitoring and management. Early integration presents opportunities for improved and productive collaboration and coordination between ecosystem restoration and contaminant assessment and management. Examples exist where early integration facilitates liability resolution and generates positive public relations. Restoration planning and implementation before the completion of the contaminated site assessment, remediation, or management process ("early restoration") can facilitate coordination with offsite restoration options and a regional approach to restoration of contaminated environments. Integration of performance monitoring, for both remedial and restoration actions, can save resources and expand the interpretive power of results. Early integration may aid experimentation, which may be more feasible on contaminated lands than in many other situations. The potential application of concepts and tools from adaptive management is discussed as a way of avoiding pitfalls and achieving benefits in

  9. [Probabilistic assessment of radionuclide accumulation in agricultural products and permissible levels of soil radioactive contamination].

    PubMed

    Spiridonov, S I; Ivanov, V V

    2013-01-01

    A number of models have been developed to assess the risks of radionuclide accumulation in agricultural products and to determine the permissible levels of soil radioactive contamination. The proposed approach takes into account uncertainties of some parameters that describe the radionuclide content in different links of food chains. The models are implemented in the form of software for on-line computations. The validity of applying the probabilistic methods for assessing the impacts of radioactive fallout as compared with the deterministic ones is demonstrated on some specific examples. A universal nature of the dependence between the risks of radionuclide content in products and the density of soil contamination is shown. Contamination limits of the agricultural land are found to vary significantly as a function of the risk size. Directions for further research are defined within the framework of this research.

  10. The rationale for simple approaches for sustainability assessment and management in contaminated land practice.

    PubMed

    Bardos, R Paul; Bone, Brian D; Boyle, Richard; Evans, Frank; Harries, Nicola D; Howard, Trevor; Smith, Jonathan W N

    2016-09-01

    The scale of land-contamination problems, and of the responses to them, makes achieving sustainability in contaminated land remediation an important objective. The Sustainable Remediation Forum in the UK (SuRF-UK) was established in 2007 to support more sustainable remediation practice in the UK. The current international interest in 'sustainable remediation' has achieved a fairly rapid consensus on concepts, descriptions and definitions for sustainable remediation, which are now being incorporated into an ISO standard. However the sustainability assessment methods being used remain diverse with a range of (mainly) semi-quantitative and quantitative approaches and tools developed, or in development. Sustainability assessment is site specific and subjective. It depends on the inclusion of a wide range of considerations across different stakeholder perspectives. Taking a tiered approach to sustainability assessment offers important advantages, starting from a qualitative assessment and moving through to semi-quantitative and quantitative assessments on an 'as required' basis only. It is also clear that there are a number of 'easy wins' that could improve performance against sustainability criteria right across the site management process. SuRF-UK has provided a checklist of 'sustainable management practices' that describes some of these. This paper provides the rationale for, and an outline of, and recently published SuRF-UK guidance on preparing for and framing sustainability assessments; carrying out qualitative sustainability assessment; and simple good management practices to improve sustainability across contaminated land management activities.

  11. Re-assessing the likelihood of airborne spread of foot-and-mouth disease at the start of the 1967-1968 UK foot-and-mouth disease epidemic.

    PubMed Central

    Gloster, J.; Freshwater, A.; Sellers, R. F.; Alexandersen, S.

    2005-01-01

    The likelihood of airborne spread of foot-and-mouth disease at the start of the 1967-1968 epidemic is re-assessed in the light of current understanding of airborne disease spread. The findings strongly confirm those made at the time that airborne virus was the most likely cause of the rapid early development of the disease out to 60 km from the source. This conclusion is reached following a detailed epidemiological, meteorological and modelling study using original records and current modelling techniques. The role played by 'lee waves' as the mechanism for the spread is investigated. It is thought that they played little part in influencing the development of the epidemic. A number of lessons learned from the work are drawn, identifying the need for further research on the quantity and characteristics of airborne virus. The results are also used to illustrate what advice would have been available to disease controllers if the outbreak had occurred in 2004. PMID:16181495

  12. Monitored Natural Attenuation of Inorganic Contaminants in Ground Water Volume 1 – Technical Basis for Assessment

    EPA Science Inventory

    This document represents the first volume of a set of three volumes that address the technical basis and requirements for assessing the potential applicability of MNA as part of a ground-water remedy for plumes with non-radionuclide and/or radionuclide inorganic contaminants. Vo...

  13. Evaluation of the Reference Envelope Approach for Assessing Toxicity in Contaminated Surficial Urban Freshwater Sediments

    EPA Science Inventory

    The reference envelope (RE) has been proposed as an alternative approach to assess sediment toxicity to overcome limitations imposed by the use of control sediments including differences in non-contaminant characteristics and low statistical power when many test sediments are com...

  14. Assessment of Adoption Gaps in Management of Aflatoxin Contamination of Groundnut ("Arachis Hypogaea" L.)

    ERIC Educational Resources Information Center

    Kumar, G. D. S.; Popat, M. N.

    2010-01-01

    One of the major impediments for diversification of groundnut ("Arachis Hypogaea" L.) as food crop is aflatoxin contamination. The study was conducted with an objective to assess the adoption gaps in aflatoxin management practices of groundnut (AMPG) and the farmer's characteristics influencing these gaps. The study used an expost-facto research…

  15. Multispecies toxicity assessment of compost produced in bioremediation of an explosives-contaminated sediment

    SciTech Connect

    Gunderson, C.A.; Napolitano, G.E.; Wicker, L.F.; Richmond, J.E.; Stewart, A.J.; Kostuk, J.M.; Gibbs, M.H.

    1997-12-01

    A multispecies terrestrial test system was used to assess the environmental effectiveness of composting for bioremediation of explosives-contaminated soils. The assessment involved comparing biological responses, from the individual to the community level, in remediated and reference composts. A 6-month greenhouse study incorporated two soil invertebrate species, three plant species and an associated symbiont, and the naturally occurring complement of soil microorganisms. Measured parameters included growth and reproduction of earthworms and isopods; soil mote diversity; soil lipid class composition as an indicator of soil microbial community structure; plant growth, photosynthesis, and reproduction; and root nodulation and symbiotic N{sub 2} fixation. Additional short-term toxicity tests of seed germination and earthworm survival were performed to supplement the mesocosm data. Compost prepared from the explosives-contaminated soil inhibited several aspects of plant growth and physiology, but few adverse effects on soil invertebrates were detected. An initial lag in earthworm and isopod reproduction occurred in the reference compost, reflecting some inherent compost differences not associated with contamination, and highlighting the importance and the difficulty of finding appropriate reference soils for assessing hazardous waste sites or remediation technologies. Nonetheless, the results from this study suggested some nonlethal effects from the contaminated-soil compost, primarily to plants. The mesocosm methodology used in this study can bridge the gap between traditional short-term toxicity testing and longer term field assessments, and provide information on ecological effects by explicitly including measurements of multiple species across several levels of ecological organization.

  16. HOLISTIC APPROACH FOR ASSESSING THE PRESENCE AND POTENTIAL IMPACTS OF WATERBORNE ENVIRONMENTAL CONTAMINANTS

    EPA Science Inventory

    As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipe...

  17. The control by ventilation of airborne bacterial transfer between hospital patients, and its assessment by means of a particle tracer

    PubMed Central

    Foord, N.; Lidwell, O. M.

    1972-01-01

    A simple and convenient particle tracer for studies of the effectiveness of isolation units and other places in limiting the airborne transfer of bacteria is described. Particles of potassium iodide 7-8 μm. diameter are generated by spraying from solution and collected on membrane filters. The particles can be identified by development with 0·1% acid palladium chloride solution, when dark brown spots approximately 100 μm. in diameter are produced. ImagesPlate 1 PMID:4503869

  18. Use of aqueous and solvent extraction to assess risk and bioavailability of contaminated soil

    SciTech Connect

    Bordelon, N.; Huebner, H.; Washburn, K.; Donnelly, K.C.

    1995-12-31

    Contaminated media at Superfund sites typically consist of complex mixtures of organic and inorganic chemicals. These mixtures are difficult to characterize, both analytically and toxicologically, especially the complex mixtures of polycyclic aromatic hydrocarbons. The current approach to risk assessment assumes that all contaminants in the soil are available for human exposure. EPA protocol uses solvent extraction to remove chemicals from the soil as a basis for estimating risk to the human population. However, contaminants that can be recovered with a solvent extract may not represent chemicals that are available for exposure. A system using aqueous extraction provides a more realistic picture of what chemicals are bioavailable through leaching and ingestion. A study was conducted with coal tar contaminated soil spiked with benzo(a)pyrene, and trinitrotoluene. Samples were extracted with hexane:acetone and water titrated to pH 2 and pH 7. HPLC analysis demonstrated up to 35% and 29% recovery of contaminants from aqueous extracts with an estimated cancer risk one order of magnitude less than that for solvent extracts. Analysis using the Salmonella/microsome assay showed that solvent extracts were genotoxic with metabolic activation while aqueous extracts showed no genotoxicity. These results suggest that aqueous extraction may be useful in determining what contaminants are available for human exposure, as well as what compounds may pose a risk to human health.

  19. Assessment of the sanitary and environmental risks posed by a contaminated industrial site.

    PubMed

    Di Sante, M; Mazzieri, F; Pasqualini, E

    2009-11-15

    Sites contaminated with hazardous material are a topical and urgent problem all over the world. In accordance with recent Italian regulations, appropriate risk assessment is required in order to determine health risks associated with contaminated sites. The paper presents a case study regarding a disused industrial plant contaminated with polycyclic aromatic hydrocarbons, heavy hydrocarbons and polychlorinated biphenyls. The site is characterized by three different topographical levels. Therefore both the characterization and the conceptual model had to be adapted to the site conditions: we divided the site into three discrete areas and we developed a separate risk assessment for each area. Besides health risk assessment, we performed ecological risk assessment for both groundwater and surface water targets, as required by Italian regulations. The future reuse scenario has not yet been defined and, consequently, risk assessment results will be useful for the remediation program. Risk assessment was supported by leaching tests and hydrocarbon "finger printing". Leaching tests allowed us to determine site-specific soil-water partition coefficient. Hydrocarbon "finger printing" allowed us to differentiate the mobility of the different hydrocarbon groups in migration analyses. We found the site required remediation based on Italian standard. We propose a simple risk-based remediation action consisting in the replacement of the upper 1m with "clean" soil and the placement of a barrier to vapors.

  20. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site at Grand Junction, Colorado. Revision 1

    SciTech Connect

    Not Available

    1994-09-01

    This risk assessment evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site.

  1. Risk assessment and prioritisation of contaminated sites on the catchment scale.

    PubMed

    Troldborg, Mads; Lemming, Gitte; Binning, Philip J; Tuxen, Nina; Bjerg, Poul L

    2008-10-23

    Contaminated sites pose a significant threat to groundwater resources worldwide. Due to limited available resources a risk-based prioritisation of the remediation efforts is essential. Existing risk assessment tools are unsuitable for this purpose, because they consider each contaminated site separately and on a local scale, which makes it difficult to compare the impact from different sites. Hence a modelling tool for risk assessment of contaminated sites on the catchment scale has been developed. The CatchRisk screening tool evaluates the risk associated with each site in terms of its ability to contaminate abstracted groundwater in the catchment. The tool considers both the local scale and the catchment scale. At the local scale, a flexible, site specific leaching model that can be adjusted to the actual data availability is used to estimate the mass flux over time from identified sites. At the catchment scale, a transport model that utilises the source flux and a groundwater model covering the catchment is used to estimate the transient impact on the supply well. The CatchRisk model was tested on a groundwater catchment for a waterworks north of Copenhagen, Denmark. Even though data scarcity limited the application of the model, the sites that most likely caused the observed contamination at the waterworks were identified. The method was found to be valuable as a basis for prioritising point sources according to their impact on groundwater quality. The tool can also be used as a framework for testing hypotheses on the origin of contamination in the catchment and for identification of unknown contaminant sources.

  2. Use of life cycle assessments to evaluate the environmental footprint of contaminated sediment remediation.

    PubMed

    Sparrevik, Magnus; Saloranta, Tuomo; Cornelissen, Gerard; Eek, Espen; Fet, Annik Magerholm; Breedveld, Gijs D; Linkov, Igor

    2011-05-15

    Ecological and human risks often drive the selection of remedial alternatives for contaminated sediments. Traditional human and ecological risk assessment (HERA) includes assessing risk for benthic organisms and aquatic fauna associated with exposure to contaminated sediments before and after remediation as well as risk for human exposure but does not consider the environmental footprint associated with implementing remedial alternatives. Assessment of environmental effects over the whole life cycle (i.e., Life Cycle Assessment, LCA) could complement HERA and help in selecting the most appropriate sediment management alternative. Even though LCA has been developed and applied in multiple environmental management cases, applications to contaminated sediments and marine ecosystems are in general less frequent. This paper implements LCA methodology for the case of the polychlorinated dibenzo-p-dioxins and -furans (PCDD/F)-contaminated Grenland fjord in Norway. LCA was applied to investigate the environmental footprint of different active and passive thin-layer capping alternatives as compared to natural recovery. The results showed that capping was preferable to natural recovery when analysis is limited to effects related to the site contamination. Incorporation of impacts related to the use of resources and energy during the implementation of a thin layer cap increase the environmental footprint by over 1 order of magnitude, making capping inferior to the natural recovery alternative. Use of biomass-derived activated carbon, where carbon dioxide is sequestered during the production process, reduces the overall environmental impact to that of natural recovery. The results from this study show that LCA may be a valuable tool for assessing the environmental footprint of sediment remediation projects and for sustainable sediment management.

  3. Logistic regression modeling to assess groundwater vulnerability to contamination in Hawaii, USA.

    PubMed

    Mair, Alan; El-Kadi, Aly I

    2013-10-01

    Capture zone analysis combined with a subjective susceptibility index is currently used in Hawaii to assess vulnerability to contamination of drinking water sources derived from groundwater. In this study, we developed an alternative objective approach that combines well capture zones with multiple-variable logistic regression (LR) modeling and applied it to the highly-utilized Pearl Harbor and Honolulu aquifers on the island of Oahu, Hawaii. Input for the LR models utilized explanatory variables based on hydrogeology, land use, and well geometry/location. A suite of 11 target contaminants detected in the region, including elevated nitrate (>1 mg/L), four chlorinated solvents, four agricultural fumigants, and two pesticides, was used to develop the models. We then tested the ability of the new approach to accurately separate groups of wells with low and high vulnerability, and the suitability of nitrate as an indicator of other types of contamination. Our results produced contaminant-specific LR models that accurately identified groups of wells with the lowest/highest reported detections and the lowest/highest nitrate concentrations. Current and former agricultural land uses were identified as significant explanatory variables for eight of the 11 target contaminants, while elevated nitrate was a significant variable for five contaminants. The utility of the combined approach is contingent on the availability of hydrologic and chemical monitoring data for calibrating groundwater and LR models. Application of the approach using a reference site with sufficient data could help identify key variables in areas with similar hydrogeology and land use but limited data. In addition, elevated nitrate may also be a suitable indicator of groundwater contamination in areas with limited data. The objective LR modeling approach developed in this study is flexible enough to address a wide range of contaminants and represents a suitable addition to the current subjective approach.

  4. Logistic regression modeling to assess groundwater vulnerability to contamination in Hawaii, USA

    NASA Astrophysics Data System (ADS)

    Mair, Alan; El-Kadi, Aly I.

    2013-10-01

    Capture zone analysis combined with a subjective susceptibility index is currently used in Hawaii to assess vulnerability to contamination of drinking water sources derived from groundwater. In this study, we developed an alternative objective approach that combines well capture zones with multiple-variable logistic regression (LR) modeling and applied it to the highly-utilized Pearl Harbor and Honolulu aquifers on the island of Oahu, Hawaii. Input for the LR models utilized explanatory variables based on hydrogeology, land use, and well geometry/location. A suite of 11 target contaminants detected in the region, including elevated nitrate (> 1 mg/L), four chlorinated solvents, four agricultural fumigants, and two pesticides, was used to develop the models. We then tested the ability of the new approach to accurately separate groups of wells with low and high vulnerability, and the suitability of nitrate as an indicator of other types of contamination. Our results produced contaminant-specific LR models that accurately identified groups of wells with the lowest/highest reported detections and the lowest/highest nitrate concentrations. Current and former agricultural land uses were identified as significant explanatory variables for eight of the 11 target contaminants, while elevated nitrate was a significant variable for five contaminants. The utility of the combined approach is contingent on the availability of hydrologic and chemical monitoring data for calibrating groundwater and LR models. Application of the approach using a reference site with sufficient data could help identify key variables in areas with similar hydrogeology and land use but limited data. In addition, elevated nitrate may also be a suitable indicator of groundwater contamination in areas with limited data. The objective LR modeling approach developed in this study is flexible enough to address a wide range of contaminants and represents a suitable addition to the current subjective approach.

  5. The First Simultaneous Airborne Measurements of BrO, BrCl HOBr in the Tropics: An Assessment on the HOx Budget and O3 Depletion

    NASA Astrophysics Data System (ADS)

    Le Breton, M. R.; Gallagher, M. W.; Shallcross, D. E.; Evans, M. J.; Carpenter, L.; Andrews, S.; Lidster, R. T.; Harris, N. R. P.; Percival, C.

    2014-12-01

    This study represents the first simultaneous airborne measurements of BrO, BrCl, Br2 and HOBr in the tropics using a chemical ionisation mass spectrometer (CIMS). The results suggest that inorganic halogen chemistry has a more significant impact on O3 depletion and oxidising capacity of the troposphere than previously thought. The CIMS instrument was operated on-board the BAe-146 FAAM research aircraft across 20 flights, as part of the CAST (Coordinated Airborne Studies in the Tropics) campaign based on Guam, Micronesia and was supported by measurements of O3 and NOx from core instruments and bromocarbons from Whole Air Samples (WAS). The mean tropospheric BrO concentration over 20 flights was calculated to be 0.69 ppt; a factor of 4 times greater than that predicted by GEOS-Chem running with a tropospheric bromine simulation. An underestimation of HOBr, Br2 and BrCl in the model, when compared to the CIMS data, will contribute to this discrepancy, thus increasing the availability of atomic Br through photolysis, however this does not compensate for the bias currently observed. The magnitude of this discrepancy and subsequent effect on O3 depletion in the tropics is assessed and possible mechanisms are proposed. The measurements of these halogenated species are further used to assess their impact on the HOx budget in the tropics via steady state estimations.

  6. CONSIDERATIONS FOR DEVELOPING A DOSIMETRY-BASED CUMULATIVE RISK ASSESSMENT APPROACH FOR MIXTURES OF ENVIRONMENTAL CONTAMINANTS (Final Report)

    EPA Science Inventory

    This final report, Considerations for Developing a Dosimetry-Based Cumulative Risk Assessment Approach for Mixtures of Environmental Contaminants, addresses the justification for developing physiologically based pharmacokinetic (PBPK) models for cumulative risk assessment....

  7. International Mussel Watch: A global assessment of environmental levels of chemical contaminants

    SciTech Connect

    Not Available

    1992-01-01

    The primary goal of the International Mussel Watch is to ascertain and assess the levels of chlorinated hydrocarbon pesticide (CHP) and polychlorinated biphenyls (PCB) in bivalves collected from coastal marine waters throughout the world. Increased use of these persistent toxic biocides may result in contamination of living coastal resources from whole ecosystems to specific food resources with consequent implication for human health and the integrity of marine communities. Another goal for the International Mussel Watch Project will be to help develop a sustainable activity for observation and monitoring chemical contamination in especially susceptible regions of the world's oceans.

  8. Approaches for assessment of terrestrial vertebrate responses to contaminants: moving beyond individual organisms

    USGS Publications Warehouse

    Albers, P.H.; Heinz, G.H.; Hall, R.J.; Albers, Peter H.; Heinz, Gary H.; Ohlendorf, Harry M.

    2000-01-01

    Conclusions: A need for a broader range ofinformation on effects of contaminants on individuals exists among the 4 classes of terrestrial vertebrates, especially mammals, reptiles, and amphibians. Separation of contaminant effects from other effects and reduction of speculative extrapolation within and among species requires information that can be produced only by combined field and laboratory investigations that incorporate seasonal or annual cycles and important spatial and interaction conditions. Assessments of contaminant effects at the population level and higher are frequently dependent on extrapolations from a lower organizational level. Actual measurements of the effects of contaminants on populations or communities, possibly in conjunction with case studies that establish relations between effects on individuals and effects on populations, are needed to reduce the uncertainty associated with these extrapolations. Associated with these assessment levels is the need for acceptable definitions of what we mean when we refer to a 'meaningful population change' or an 'effect on communities or ecosystems.' At these higher levels of organization we are also confronted with the need for procedures useful for separating contaminant effects from effects caused by other environmental conditions. Although the bulk of literature surveyed was of the focused cause-and-effect type that is necessary for proving relations between contaminants and wildlife, community or ecosystem field assessments, as sometimes performed with reptiles and amphibians, might be a useful alternative for estimating the potential of a contaminant to cause environmental harm. Assumptions about the special usefulness of reptiles and amphibians as environmental indicators ought to be tested with comparisons to mammals and birds. Information on the effects of contaminants above the individual level is needed to generate accurate estimates of the potential consequences of anthropogenic pollution (e

  9. Developing methods to assess and predict the population level effects of environmental contaminants.

    USGS Publications Warehouse

    Emlen, J.M.; Springman, K.R.

    2007-01-01

    The field of ecological toxicity seems largely to have drifted away from what its title implies--assessing and predicting the ecological consequences of environmental contaminants--moving instead toward an emphasis on individual effects and physiologic case studies. This paper elucidates how a relatively new ecological methodology, interaction assessment (INTASS), could be useful in addressing the field's initial goals. Specifically, INTASS is a model platform and methodology, applicable across a broad array of taxa and habitat types, that can be used to construct population dynamics models from field data. Information on environmental contaminants and multiple stressors can be incorporated into these models in a form that bypasses the problems inherent in assessing uptake, chemical interactions in the environment, and synergistic effects in the organism. INTASS can, therefore, be used to evaluate the effects of contaminants and other stressors at the population level and to predict how changes in stressor levels or composition of contaminant mixtures, as well as various mitigation measures, might affect population dynamics.

  10. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The Airborne Oceanographic Lidar (AOL), a spatially scanning range-gated device installed on board a NASA C-54 aircraft, is described. The AOL system is capable of measuring topographical relief or water depth (bathymetry) with a range resolution of plus or minus 0.3 m in the vertical dimension. The system may also be used to measure fluorescent spectral signatures from 3500 to 8000 A with a resolution of 100 A. Potential applications of the AOL, including sea state measurements, water transparency assessments, oil spill identification, effluent identification and crop cover assessment are also mentioned.

  11. Assessment of metal contamination in coastal sediments, seawaters and bivalves of the Mediterranean Sea coast, Egypt.

    PubMed

    El-Sorogy, Abdelbaset S; Attiah, Abdullah

    2015-12-30

    In order to assess metal contamination on the Mediterranean coast of Egypt, 45 sediment samples, seawaters and bivalve specimens were collected from Rosetta coastal area for Mg, Al, K, Fe, Sr, Zn, Pb, Mn, As, Ce, Ni, Cr and Zr analyses by Inductively Coupled Plasma-Mass Spectrometer. The Enrichment Factor (EF), the Geoaccumulation Index (Igeo) and the Contamination Factor (CF) indicated that the coastal sediments of Rosetta area were severely enriched, strongly polluted with As, Pb and very highly contaminated with As, Pb, Ni, Ce, mostly as a result of anthropogenic inputs. Comparison with other samples from the Arabian Gulf, Red Sea and abroad coasts suggested that the studied samples have higher concentrations of Fe, Pb, As, Zn and Ni. The natural sources of heavy metals in the study area are attributed to weathering and decomposition of mountain ranges of the Sudan and Ethiopia, while the anthropogenic ones are the metals produced from industrial, sewage, irrigation and urban runoff.

  12. Assessment of metal contamination in coastal sediments, seawaters and bivalves of the Mediterranean Sea coast, Egypt.

    PubMed

    El-Sorogy, Abdelbaset S; Attiah, Abdullah

    2015-12-30

    In order to assess metal contamination on the Mediterranean coast of Egypt, 45 sediment samples, seawaters and bivalve specimens were collected from Rosetta coastal area for Mg, Al, K, Fe, Sr, Zn, Pb, Mn, As, Ce, Ni, Cr and Zr analyses by Inductively Coupled Plasma-Mass Spectrometer. The Enrichment Factor (EF), the Geoaccumulation Index (Igeo) and the Contamination Factor (CF) indicated that the coastal sediments of Rosetta area were severely enriched, strongly polluted with As, Pb and very highly contaminated with As, Pb, Ni, Ce, mostly as a result of anthropogenic inputs. Comparison with other samples from the Arabian Gulf, Red Sea and abroad coasts suggested that the studied samples have higher concentrations of Fe, Pb, As, Zn and Ni. The natural sources of heavy metals in the study area are attributed to weathering and decomposition of mountain ranges of the Sudan and Ethiopia, while the anthropogenic ones are the metals produced from industrial, sewage, irrigation and urban runoff. PMID:26563548

  13. A hierarchical approach to ecological assessment of contaminated soils at Aberdeen Proving Ground, USA

    SciTech Connect

    Kuperman, R.G.

    1995-12-31

    Despite the expansion of environmental toxicology studies over the past decade, soil ecosystems have largely been ignored in ecotoxicological studies in the United States. The objective of this project was to develop and test the efficacy of a comprehensive methodology for assessing ecological impacts of soil contamination. A hierarchical approach that integrates biotic parameters and ecosystem processes was used to give insight into the mechanisms that lead to alterations in the structure and function of soil ecosystems in contaminated areas. This approach involved (1) a thorough survey of the soil biota to determine community structure, (2) laboratory and field tests on critical ecosystem processes, (3) toxicity trials, and (4) the use of spatial analyses to provide input to the decision-making, process. This methodology appears to, offer an efficient and potentially cost-saving tool for remedial investigations of contaminated sites.

  14. Global assessment of exposure to faecal contamination through drinking water based on a systematic review

    PubMed Central

    Bain, Robert; Cronk, Ryan; Hossain, Rifat; Bonjour, Sophie; Onda, Kyle; Wright, Jim; Yang, Hong; Slaymaker, Tom; Hunter, Paul; Prüss-Ustün, Annette; Bartram, Jamie

    2014-01-01

    Objectives To estimate exposure to faecal contamination through drinking water as indicated by levels of Escherichia coli (E. coli) or thermotolerant coliform (TTC) in water sources. Methods We estimated coverage of different types of drinking water source based on household surveys and censuses using multilevel modelling. Coverage data were combined with water quality studies that assessed E. coli or TTC including those identified by a systematic review (n = 345). Predictive models for the presence and level of contamination of drinking water sources were developed using random effects logistic regression and selected covariates. We assessed sensitivity of estimated exposure to study quality, indicator bacteria and separately considered nationally randomised surveys. Results We estimate that 1.8 billion people globally use a source of drinking water which suffers from faecal contamination, of these 1.1 billion drink water that is of at least ‘moderate’ risk (>10 E. coli or TTC per 100 ml). Data from nationally randomised studies suggest that 10% of improved sources may be ‘high’ risk, containing at least 100 E. coli or TTC per 100 ml. Drinking water is found to be more often contaminated in rural areas (41%, CI: 31%–51%) than in urban areas (12%, CI: 8–18%), and contamination is most prevalent in Africa (53%, CI: 42%–63%) and South-East Asia (35%, CI: 24%–45%). Estimates were not sensitive to the exclusion of low quality studies or restriction to studies reporting E. coli. Conclusions Microbial contamination is widespread and affects all water source types, including piped supplies. Global burden of disease estimates may have substantially understated the disease burden associated with inadequate water services. PMID:24811893

  15. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado

    SciTech Connect

    1995-08-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase I), and the Ground Water Project (phase II). For the UMTRA Project site located near Naturita, Colorado (the Naturita site), phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation`s Upper Burbank Repository at Uravan, Colorado, about 13 road miles (mi) (21 kilometers [km]) to the northwest. No uranium mill tailings are involved because the tailings were removed from the Naturita site and placed at Coke Oven, Colorado, during 1977 to 1979. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health or the environment; and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water, or surface water that has received contaminated ground water. Therefore, a risk assessment is conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment.

  16. Assessing the fate of biodegradable volatile organic contaminants in unsaturated soil filter systems

    NASA Astrophysics Data System (ADS)

    Thullner, Martin; de Biase, Cecilia; Hanzel, Joanna; Reger, Daniel; Wick, Lukas; Oswald, Sascha; van Afferden, Manfred; Schmidt, Axel; Reiche, Nils; Jechalke, Sven

    2010-05-01

    The assessment of contaminant biodegradation in the subsurface is challenged by various abiotic processes leading to a reduction of contaminant concentration without a destructive mass removal of the contaminant. In unsaturated porous media, this interplay of processes is further complicated by volatilization. Many organic contaminants are sufficiently volatile to allow for significant fluxes from the water phase into the soil air, which can eventually lead to an emission of contaminants into the atmosphere. Knowledge of the magnitude of these emissions is thus required to evaluate the efficiency of bioremediation in such porous media and to estimate potential risks due to these emissions. In the present study, vertical flow constructed wetlands were investigated at the pilot scale as part of the SAFIRA II project. The investigated wetland system is intermittently irrigated by contaminated groundwater containing the volatile compounds benzene and MTBE. Measured concentration at the in- and outflow of the system demonstrate a high mass removal rate, but the highly transient flow and transport processes in the system challenge the quantification of biodegradation and volatilization and their contribution to the observed mass removal. By a combination of conservative solute tracer tests, stable isotope fractionation and measurements of natural radon concentration is the treated groundwater is was possible to determine the contribution of biodegradation and volatilization to total mass removal. The results suggest that for the investigated volatile compounds biodegradation is the dominating mass removal process with volatilization contributing only to minor or negligible amounts. These results can be confirmed by reactive transport simulations and were further supported by laboratory studies showing that also gas phase gradients of volatile compounds can be affected by biodegradation suggesting the unsaturated zone to act as a biofilter for contaminants in the soil air.

  17. Design and Performance Assessment of a Stable Astigmatic Herriott Cell for Trace Gas Measurements on Airborne Platforms

    NASA Technical Reports Server (NTRS)

    Dyroff, Christoph; Fried, Alan; Richter, Dirk; Walega, James G.; Zahniser, Mark S.; McManus, J. Barry

    2005-01-01

    The present paper discusses a new, more stable, astigmatic Herriott cell employing carbon fiber stabilizing rods. Laboratory tests using a near-IR absorption feature of CO at 1564.168-nm revealed a factor of two improvement in measurement stability compared with the present commercial design when the sampling pressure was changed by +/-2 Torr around 50 Torr. This new cell should significantly enhance our efforts to measure trace gases employing pathlengths of 100 to 200-meters on airborne platforms with minimum detectable line center absorbances of less than 10(exp -6).

  18. Assessment of Superflux relative to remote sensing. [airborne remote sensing of the Chesapeake Bay plume and shelf regions

    NASA Technical Reports Server (NTRS)

    Campbell, J. W.

    1981-01-01

    The state-of-the-art advancements in remote sensor technology due to the Superflux program are examined. Three major individual sensor technologies benefitted from the program: laser fluorosensors, optical-range scanners, and passive microwave sensors. Under Superflux, convincing evidence was obtained that the airborne oceanographic lidar fluorosensor can map chlorophyll, i.e., is linear, over a wide range from less than 0.5 to 5.0 mg/cu m. The lidar oceanographic probe dual-excitation concept for addressing phytoplankton color group composition was also demonstrated convincingly. Algorithm development, real time capabilities, and multisensor integration are also addressed.

  19. Baseline risk assessment of ground water contamination at the inactive uriniferous lignite ashing site near Belfield, North Dakota

    SciTech Connect

    1994-08-01

    This Baseline Risk Assessment of Ground Water Contamination at the Inactive Uraniferous Lignite Ashing Site Near Belfield, North Dakota, evaluates potential impacts to public health or the environment resulting from ground water contamination at the site where coal containing uranium was burned to produce uranium. The US Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project is evaluating plans to remedy soil and ground water contamination at the site. Phase I of the UMTRA Project consists of determining the extent of soil contamination. Phase II of the UMTRA Project consists of evaluating ground water contamination. Under Phase II, results of this risk assessment will help determine what remedial actions may be necessary for contaminated ground water at the site. This risk assessment evaluates the potential risks to human health and the environment resulting from exposure to contaminated ground water as it relates to historic processing activities at the site. Potential risk is quantified for constituents introduced from the processing activities, and not for those constituents naturally occurring in water quality in the site vicinity. Background ground water quality has the potential to cause adverse health effects from exposure through drinking. Any risks associated with contaminants attributable to site activities are incremental to these risks from background ground water quality. This incremental risk from site-related contaminants is quantified in this risk assessment. The baseline risk from background water quality is incorporated only into the assessment of potential chemical interactions and the definition of the overall site condition.

  20. A Contamination Vulnerability Assessment for the Santa Clara and San Mateo County Groundwater Basins

    SciTech Connect

    Moran, J E; Hudson, G B; Eaton, G F; Leif, R

    2004-01-06

    In response to concerns expressed by the California Legislature and the citizenry of the State of California, the State Water Resources Control Board (SWRCB), implemented a program to assess groundwater quality, and provide a predictive capability for identifying areas that are vulnerable to contamination. The program was initiated in response to concern over public supply well closures due to contamination by chemicals such as MtBE from gasoline, and solvents from industrial operations. As a result of this increased awareness regarding groundwater quality, the Supplemental Report of the 1999 Budget Act mandated the SWRCB to develop a comprehensive ambient groundwater-monitoring plan, and led to the initiation of the Ambient Groundwater Monitoring and Assessment (GAMA) Program. The primary objective of the GAMA Program is to assess the water quality and to predict the relative susceptibility to contamination of groundwater resources throughout the state of California. Under the GAMA program, scientists from Lawrence Livermore National Laboratory (LLNL) collaborate with the SWRCB, the U.S. Geological Survey, the California Department of Health Services (DHS), and the California Department of Water Resources (DWR) to implement this groundwater assessment program. In 2001 and 2002, LLNL carried out this vulnerability study in the groundwater basins of Santa Clara County and San Mateo County, located to the south of the city of San Francisco. The goal of the study is to provide a probabilistic assessment of the relative vulnerability of groundwater used for the public water supply to contamination from surface sources. This assessment of relative contamination vulnerability is made based on the results of two types of analyses that are not routinely carried out at public water supply wells: ultra low-level measurement of volatile organic compounds (VOCs), and groundwater age dating (using the tritium-helium-3 method). In addition, stable oxygen isotope measurements

  1. California GAMA Program: A Contamination Vulnerability Assessment for the Bakersfield Area

    SciTech Connect

    Moran, J E; Hudson, G B; Eaton, G F; Leif, R

    2004-11-01

    In response to concerns expressed by the California Legislature and the citizenry of the State of California, the State Water Resources Control Board (SWRCB), implemented a program to assess groundwater quality, and provide a predictive capability for identifying areas that are vulnerable to contamination. The program was initiated in response to concern over public supply well closures due to contamination by chemicals such as MTBE from gasoline, and solvents from industrial operations. As a result of this increased awareness regarding groundwater quality, the Supplemental Report of the 1999 Budget Act mandated the SWRCB to develop a comprehensive ambient groundwater-monitoring plan, and led to the initiation of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The primary objective of the GAMA Program is to assess the water quality and to predict the relative susceptibility to contamination of groundwater resources throughout the state of California. Under the GAMA program, scientists from Lawrence Livermore National Laboratory (LLNL) collaborate with the SWRCB, the U.S. Geological Survey (USGS), the California Department of Health Services (DHS), and the California Department of Water Resources (DWR) to implement this groundwater assessment program. In 2003, LLNL carried out this vulnerability study in the groundwater basin that underlies Bakersfield, in the southern San Joaquin Valley. The goal of the study is to provide a probabilistic assessment of the relative vulnerability of groundwater used for the public water supply to contamination from surface sources. This assessment of relative contamination vulnerability is made based on the results of two types of analyses that are not routinely carried out at public water supply wells: ultra low-level measurement of volatile organic compounds (VOCs), and groundwater age dating (using the tritium-helium-3 method). In addition, stable oxygen isotope measurements help determine the recharge water

  2. Assessment of post-contamination treatments affecting different bonding stages to dentin

    PubMed Central

    Elkassas, Dina; Arafa, Abla

    2016-01-01

    Objectives: To assess the effect of cleansing treatments following saliva and blood contamination at different bonding stages to dentin. Materials and Methods: Labial surfaces of 168 permanent maxillary central incisors were ground flat exposing superficial dentin. Specimens were divided into: uncontaminated control (A), contamination after etching (B), contamination after adhesive application (C), contamination after adhesive polymerization (D). Groups were further subdivided according to cleansing treatments into: rinsing (B1, C1, D1), re-etching (B2, D3), sodium hypochlorite application (B3), ethyl alcohol application (C2), acetone application (C3), rinsing and rebonding (D2), re-etching and rebonding (D4). Composite microcylinders were bonded to treated substrates and shear loaded micro-shear bond strength (μSBS) until failure and treated surfaces were examined with scanning electron microscope. Debonded surfaces were classified as adhesive, cohesive or mixed failure. The data were analyzed using one-way ANOVA and Tukey's post hoc test. Results: The μSBS values were ranked as follow; Group B: A > B3 > B2 > B1 > B, Group C: A > C3 > C2 > C1 > C, Group D: A > D4 > D1 = D2 ≥ D3. Debonded surfaces showed adhesive failure in Group B while cohesive failure in Groups C and D. Conclusions: Cleansing treatments differ according to bonding step; re-etching then rebonding suggested if etched substrate or polymerized adhesive were contaminated while acetone application decontaminated affected unpolymerized adhesive. PMID:27403048

  3. Chemical contamination assessment of Gulf of Mexico oysters in response to hurricanes Katrina and Rita.

    PubMed

    Johnson, W E; Kimbrough, K L; Lauenstein, G G; Christensen, J

    2009-03-01

    Hurricane Katrina made landfall on August 29, 2005 and caused widespread devastation along the central Gulf Coast states. Less than a month later Hurricane Rita followed a similar track slightly west of Katrina's. A coordinated multi-agency response followed to collect water, sediment and tissue samples for a variety of chemical, biological and toxicological indicators. The National Oceanic and Atmospheric Administration's National Status and Trends Program (NS&T) participated in this effort by measuring chemical contamination in sediment and oyster tissue as part of the Mussel Watch Program, a long-term monitoring program to assess spatial and temporal trends in a wide range of coastal pollutants. This paper describes results for contaminants measured in oyster tissue collected between September 29 and October 10, 2005 and discusses the results in the context of Mussel Watch and its 20-year record of chemical contamination in the region and the nation. In general, levels of metals in oyster tissue were higher then pre- hurricane levels while organic contaminants were at or near record lows. No contaminant reported here exceeded the FDA action level for food safety.

  4. Long-term assessment of contaminated articles from the Chernobyl reactor.

    PubMed

    Alkhomashi, N; Monged, M H E

    2015-06-01

    The Chernobyl accident caused a release of radioactive materials from the reactor into the environment. This event contaminated people, their surroundings and their personal property, especially in the zone around the reactor. Among the affected individuals were British students who were studying in Minsk and Kiev at the time of the Chernobyl accident. These students were exposed to external and internal radiation, and the individuals' articles of clothing were contaminated. The primary objective of this study was to analyze a sample of this contaminated clothing 20 years after the accident using three different detectors, namely, a BP4/4C scintillation detector, a Min-Con Geiger-Müller tube detector and a high-purity germanium (HPGe) detector. The clothing articles were initially assessed and found not to be significantly contaminated. However, there were several hot spots of contamination in various regions of the articles. The net count rates for these hot spots were in the range of 10.00 ± 3.16 c/s to 41.00 ± 6.40 c/s when the BP4/4C scintillation detector was used. The HPGe detector was used to identify the radionuclides present in the clothing, and the results indicated that the only active radionuclide was (137)Cs because of this isotope's long half-life.

  5. Assessing microbial activities in metal contaminated agricultural volcanic soils--An integrative approach.

    PubMed

    Parelho, C; Rodrigues, A S; Barreto, M C; Ferreira, N G C; Garcia, P

    2016-07-01

    Volcanic soils are unique naturally fertile resources, extensively used for agricultural purposes and with particular physicochemical properties that may result in accumulation of toxic substances, such as trace metals. Trace metal contaminated soils have significant effects on soil microbial activities and hence on soil quality. The aim of this study is to determine the soil microbial responses to metal contamination in volcanic soils under different agricultural land use practices (conventional, traditional and organic), based on a three-tier approach: Tier 1 - assess soil microbial activities, Tier 2 - link the microbial activity to soil trace metal contamination and, Tier 3 - integrate the microbial activity in an effect-based soil index (Integrative Biological Response) to score soil health status in metal contaminated agricultural soils. Our results showed that microbial biomass C levels and soil enzymes activities were decreased in all agricultural soils. Dehydrogenase and β-glucosidase activities, soil basal respiration and microbial biomass C were the most sensitive responses to trace metal soil contamination. The Integrative Biological Response value indicated that soil health was ranked as: organic>traditional>conventional, highlighting the importance of integrative biomarker-based strategies for the development of the trace metal "footprint" in Andosols. PMID:27057992

  6. Performance of different assessment methods to evaluate contaminant sources and fate in a coastal aquifer.

    PubMed

    Sbarbati, C; Colombani, N; Mastrocicco, M; Aravena, R; Petitta, M

    2015-10-01

    The present study deals with the application of different monitoring techniques and numerical models to characterize coastal aquifers affected by multiple sources of contamination. Specifically, equivalent freshwater heads in 243 monitoring wells were used to reconstruct the piezometric map of the studied aquifer; flow meter tests were carried out to infer vertical groundwater fluxes at selected wells; deuterium and oxygen isotopes were used to identify the groundwater origin, and tritium was analyzed to estimate the residence time; compound-specific isotope analyses and microbial analyses were employed to track different sources of contamination and their degradation; numerical modelling was used to estimate and verify groundwater flow direction and magnitude throughout the aquifer. The comparison of the information level for each technique allowed determining which of the applied approaches showed the best results to locate the possible sources and better understanding of the fate of the contaminants. This study reports a detailed site characterization process and outcomes for a coastal industrial site, where a comprehensive conceptual model of pollution and seawater intrusion has been built using different assessment methods. Information and results from this study encourages combining different methods for the design and implementation of the monitoring activities in real-life coastal contaminated sites in order to develop an appropriate strategy for control and remediation of the contamination.

  7. Effect of proximity to a cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens and evaluation of the potential for airborne transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of proximity to a beef cattle feedlot on E. coli O157:H7 contamination of leafy greens was examined. In each of two years, leafy greens were planted to nine plots located 60, 120, and 180 meters from a cattle feedlot (3 plots each distance). Leafy greens, feedlot manure, and bioaerosol ...

  8. Assessment of concentrations and effects of organohalogen contaminants in a terrestrial passerine, the European starling.

    PubMed

    Eng, Margaret L; Williams, Tony D; Letcher, Robert J; Elliott, John E

    2014-03-01

    European starlings (Sturnus vulgaris) are a valuable model species for the assessment of concentrations and effects of environmental contaminants in terrestrial birds. Polybrominated diphenyl ethers (PBDEs) are found in birds throughout the world, but relatively little is known of their concentrations or effects in free-living terrestrial passerines. We used a nest box population of European starlings to 1) measure the variation in egg concentrations of persistent organohalogen contaminants at an agricultural site, and 2) assess whether individual variation in PBDE concentrations in eggs was related to reproductive parameters, as well as maternal or nestling characteristics including body condition, thyroid hormones, oxidative stress, and hematocrit. As PBDEs were the main contaminant class of interest, we only assessed a subset of eggs for other organohalogen contaminants to establish background concentrations. Exposure to organohalogen contaminants was extremely variable over this relatively small study area. Geometric mean wet weight concentrations (range in brackets) of the major contaminants were 36.5 (12-174) ng/g ΣDDT (n=6 eggs) and 10.9 (2-307) ng/g ΣPBDEs (n=14). ΣPCBs at 3.58 (1.5-6.4) ng/g (n=6) were lower and less variable. There were low levels of other organochlorine (OC) pesticides such as dieldrin (2.02 ng/g), chlordanes (1.11 ng/g) and chlorobenzenes (0.23 ng/g). The only form of DDT detected was p,p'-DDE. The congener profiles of PBDEs and PCBs reflect those of industrial mixtures (i.e. DE-71, Aroclors 1254, 1260 and 1262). For all of the contaminant classes, concentrations detected in eggs at our study site were below levels previously reported to cause effects. Due to small sample sizes, we did not assess the relationship between ΣPCBs or ΣOCs and adult or chick condition. We observed no correlative relationships between individual variation in PBDE concentrations in starling eggs and reproductive success, maternal condition, or nestling

  9. Gastrointestinal campylobacteriosis in industrialised countries: comparison of the disease situation with salmonellosis, and microbiological contamination assessment.

    PubMed

    Laroche, M; Magras, C

    2013-12-01

    The science-based assessment of foodborne zoonotic risk is used to evaluate the public health impact of a hazard and to guide public decision-making on control measures. Key information for the hazard characterisation and microbiological contamination assessment phases of risk assessment may be obtained from the collection and structured statistical analysis of international data. This approach was used for the hazard characterisation phase of a risk assessment of gastrointestinal campylobacteriosis and salmonellosis in 30 industrialised countries over the period 2005-2009. The results showed an overall increase in the annual ratio campylobacteriosis/salmonellosis (R(moy) > 2), despite significant differences among countries (P < 0.0001). For countries with complete data over 20 years, the results showed significantly higher exposure to campylobacteriosis among certain population segments (men, children under 5 years of age and adults aged between 20 and 30), as well as in summer. A number of paired factors (Campylobacter species/animal species-meat type) are observed in this consumer exposure. However, the overall rate of bacterial transfer in meat supply chains varies widely, with far lower values for cattle (0.16) and pigs (0.24) than for poultry (0.60) and chickens (1.17). A lack of harmonised epidemiological data on the contamination status of foodstuffs (frequency, level, site, and species) further hampers the accurate identification of critical points of contamination and of the spread of the hazard throughout the food chain. PMID:24761724

  10. Uncertainties in human health risk assessment of environmental contaminants: A review and perspective.

    PubMed

    Dong, Zhaomin; Liu, Yanju; Duan, Luchun; Bekele, Dawit; Naidu, Ravi

    2015-12-01

    Addressing uncertainties in human health risk assessment is a critical issue when evaluating the effects of contaminants on public health. A range of uncertainties exist through the source-to-outcome continuum, including exposure assessment, hazard and risk characterisation. While various strategies have been applied to characterising uncertainty, classical approaches largely rely on how to maximise the available resources. Expert judgement, defaults and tools for characterising quantitative uncertainty attempt to fill the gap between data and regulation requirements. The experiences of researching 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) illustrated uncertainty sources and how to maximise available information to determine uncertainties, and thereby provide an 'adequate' protection to contaminant exposure. As regulatory requirements and recurring issues increase, the assessment of complex scenarios involving a large number of chemicals requires more sophisticated tools. Recent advances in exposure and toxicology science provide a large data set for environmental contaminants and public health. In particular, biomonitoring information, in vitro data streams and computational toxicology are the crucial factors in the NexGen risk assessment, as well as uncertainties minimisation. Although in this review we cannot yet predict how the exposure science and modern toxicology will develop in the long-term, current techniques from emerging science can be integrated to improve decision-making. PMID:26386465

  11. Risk assessment for furan contamination through the food chain in Belgian children.

    PubMed

    Scholl, Georges; Huybrechts, Inge; Humblet, Marie-France; Scippo, Marie-Louise; De Pauw, Edwin; Eppe, Gauthier; Saegerman, Claude

    2012-08-01

    Young, old, pregnant and immuno-compromised persons are of great concern for risk assessors as they represent the sub-populations most at risk. The present paper focuses on risk assessment linked to furan exposure in children. Only the Belgian population was considered because individual contamination and consumption data that are required for accurate risk assessment were available for Belgian children only. Two risk assessment approaches, the so-called deterministic and probabilistic, were applied and the results were compared for the estimation of daily intake. A significant difference between the average Estimated Daily Intake (EDI) was underlined between the deterministic (419 ng kg⁻¹ body weight (bw) day⁻¹) and the probabilistic (583 ng kg⁻¹ bw day⁻¹) approaches, which results from the mathematical treatment of the null consumption and contamination data. The risk was characterised by two ways: (1) the classical approach by comparison of the EDI to a reference dose (RfD(chronic-oral)) and (2) the most recent approach, namely the Margin of Exposure (MoE) approach. Both reached similar conclusions: the risk level is not of a major concern, but is neither negligible. In the first approach, only 2.7 or 6.6% (respectively in the deterministic and in the probabilistic way) of the studied population presented an EDI above the RfD(chronic-oral). In the second approach, the percentage of children displaying a MoE above 10,000 and below 100 is 3-0% and 20-0.01% in the deterministic and probabilistic modes, respectively. In addition, children were compared to adults and significant differences between the contamination patterns were highlighted. While major contamination was linked to coffee consumption in adults (55%), no item predominantly contributed to the contamination in children. The most important were soups (19%), dairy products (17%), pasta and rice (11%), fruit and potatoes (9% each). PMID:22632631

  12. An integrated fuzzy-stochastic modeling approach for risk assessment of groundwater contamination.

    PubMed

    Li, Jianbing; Huang, Gordon H; Zeng, Guangming; Maqsood, Imran; Huang, Yuefei

    2007-01-01

    An integrated fuzzy-stochastic risk assessment (IFSRA) approach was developed in this study to systematically quantify both probabilistic and fuzzy uncertainties associated with site conditions, environmental guidelines, and health impact criteria. The contaminant concentrations in groundwater predicted from a numerical model were associated with probabilistic uncertainties due to the randomness in modeling input parameters, while the consequences of contaminant concentrations violating relevant environmental quality guidelines and health evaluation criteria were linked with fuzzy uncertainties. The contaminant of interest in this study was xylene. The environmental quality guideline was divided into three different strictness categories: "loose", "medium" and "strict". The environmental-guideline-based risk (ER) and health risk (HR) due to xylene ingestion were systematically examined to obtain the general risk levels through a fuzzy rule base. The ER and HR risk levels were divided into five categories of "low", "low-to-medium", "medium", "medium-to-high" and "high", respectively. The general risk levels included six categories ranging from "low" to "very high". The fuzzy membership functions of the related fuzzy events and the fuzzy rule base were established based on a questionnaire survey. Thus the IFSRA integrated fuzzy logic, expert involvement, and stochastic simulation within a general framework. The robustness of the modeling processes was enhanced through the effective reflection of the two types of uncertainties as compared with the conventional risk assessment approaches. The developed IFSRA was applied to a petroleum-contaminated groundwater system in western Canada. Three scenarios with different environmental quality guidelines were analyzed, and reasonable results were obtained. The risk assessment approach developed in this study offers a unique tool for systematically quantifying various uncertainties in contaminated site management, and it also

  13. An evaluation of the effectiveness of utilizing bioassays in the assessment of contaminated sites

    SciTech Connect

    Mroz, R.; Carter, J.; Tay, K.L.; Doe, K.

    1995-12-31

    The purpose of this study was to evaluate the battery of biological tests recommended by Environment Canada in the document ``A Review of Whole Organism Bioassays for Assessing the Quality of Soil, Freshwater Sediment and Freshwater in Canada`` for the assessment of contaminated sites. Soil and sediment samples were collected from three contaminated sites in the Atlantic Region and subjected to biological and chemical tests. Four bioassays were conducted on the soil samples: lettuce (Lactuca sativa) seedling emergence, algal (Selenastrum capricornutum) population growth inhibition, earthworm (Eisenia andrel) survival and inhibition of light output in Microtox (Vibrio fischeri). Soil samples collected from Makinsons, Newfoundland had elevated levels of PCBs, total petroleum hydrocarbons (TPH) and heavy metals and showed some toxicity in the algal population growth inhibition test. Samples from the Weldon, New Brunswick site were high in TPH and were marginally toxic to Microtox and lettuce seedlings. The earthworm survival test did not appear sensitive to any of the contaminated soil samples. Freshwater sediment samples, collected from Five Island Lake, Nova Scotia had elevated PCB and heavy metal concentrations. These samples underwent four biological tests: midge (Chironomus tentans) survival, amphipod (Hyalella azteca) survival, algal population growth inhibition and Microtox. At 100% concentration, the sediment was toxic to the first three species, with toxicities ranging from marginal to high. For all samples, the bioassay results were compared to chemical analyses and, in most cases, there was a positive correlation between contaminant concentrations and toxicity.

  14. Assessment of Environmental Contamination and Environmental Decontamination Practices within an Ebola Holding Unit, Freetown, Sierra Leone

    PubMed Central

    Youkee, Daniel; Brown, Colin S.; Lilburn, Paul; Shetty, Nandini; Brooks, Tim; Simpson, Andrew; Bentley, Neil; Lado, Marta; Kamara, Thaim B.; Walker, Naomi F.; Johnson, Oliver

    2015-01-01

    Evidence to inform decontamination practices at Ebola holding units (EHUs) and treatment centres is lacking. We conducted an audit of decontamination procedures inside Connaught Hospital EHU in Freetown, Sierra Leone, by assessing environmental swab specimens for evidence of contamination with Ebola virus by RT-PCR. Swabs were collected following discharge of Ebola Virus Disease (EVD) patients before and after routine decontamination. Prior to decontamination, Ebola virus RNA was detected within a limited area at all bedside sites tested, but not at any sites distant to the bedside. Following decontamination, few areas contained detectable Ebola virus RNA. In areas beneath the bed there was evidence of transfer of Ebola virus material during cleaning. Retraining of cleaning staff reduced evidence of environmental contamination after decontamination. Current decontamination procedures appear to be effective in eradicating persistence of viral RNA. This study supports the use of viral swabs to assess Ebola viral contamination within the clinical setting. We recommend that regular refresher training of cleaning staff and audit of environmental contamination become standard practice at all Ebola care facilities during EVD outbreaks. PMID:26692018

  15. Assessment of Environmental Contamination and Environmental Decontamination Practices within an Ebola Holding Unit, Freetown, Sierra Leone.

    PubMed

    Youkee, Daniel; Brown, Colin S; Lilburn, Paul; Shetty, Nandini; Brooks, Tim; Simpson, Andrew; Bentley, Neil; Lado, Marta; Kamara, Thaim B; Walker, Naomi F; Johnson, Oliver

    2015-01-01

    Evidence to inform decontamination practices at Ebola holding units (EHUs) and treatment centres is lacking. We conducted an audit of decontamination procedures inside Connaught Hospital EHU in Freetown, Sierra Leone, by assessing environmental swab specimens for evidence of contamination with Ebola virus by RT-PCR. Swabs were collected following discharge of Ebola Virus Disease (EVD) patients before and after routine decontamination. Prior to decontamination, Ebola virus RNA was detected within a limited area at all bedside sites tested, but not at any sites distant to the bedside. Following decontamination, few areas contained detectable Ebola virus RNA. In areas beneath the bed there was evidence of transfer of Ebola virus material during cleaning. Retraining of cleaning staff reduced evidence of environmental contamination after decontamination. Current decontamination procedures appear to be effective in eradicating persistence of viral RNA. This study supports the use of viral swabs to assess Ebola viral contamination within the clinical setting. We recommend that regular refresher training of cleaning staff and audit of environmental contamination become standard practice at all Ebola care facilities during EVD outbreaks. PMID:26692018

  16. Assessment of Environmental Contamination and Environmental Decontamination Practices within an Ebola Holding Unit, Freetown, Sierra Leone.

    PubMed

    Youkee, Daniel; Brown, Colin S; Lilburn, Paul; Shetty, Nandini; Brooks, Tim; Simpson, Andrew; Bentley, Neil; Lado, Marta; Kamara, Thaim B; Walker, Naomi F; Johnson, Oliver

    2015-01-01

    Evidence to inform decontamination practices at Ebola holding units (EHUs) and treatment centres is lacking. We conducted an audit of decontamination procedures inside Connaught Hospital EHU in Freetown, Sierra Leone, by assessing environmental swab specimens for evidence of contamination with Ebola virus by RT-PCR. Swabs were collected following discharge of Ebola Virus Disease (EVD) patients before and after routine decontamination. Prior to decontamination, Ebola virus RNA was detected within a limited area at all bedside sites tested, but not at any sites distant to the bedside. Following decontamination, few areas contained detectable Ebola virus RNA. In areas beneath the bed there was evidence of transfer of Ebola virus material during cleaning. Retraining of cleaning staff reduced evidence of environmental contamination after decontamination. Current decontamination procedures appear to be effective in eradicating persistence of viral RNA. This study supports the use of viral swabs to assess Ebola viral contamination within the clinical setting. We recommend that regular refresher training of cleaning staff and audit of environmental contamination become standard practice at all Ebola care facilities during EVD outbreaks.

  17. Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado. Revision 1

    SciTech Connect

    Not Available

    1994-04-01

    This report evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells to determine the potential for immediate human health and environmental impacts. This risk assessment evaluates the most contaminated groundwater that flows beneath the processing site towards the Gunnison River. The monitor wells that have consistently shown the highest concentration of most contaminants are used in this risk assessment. This risk assessment will be used in conjunction with additional activities and documents to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.

  18. A comparison between satellite and airborne multispectral data for the assessment of Mangrove areas in the eastern Caribbean

    SciTech Connect

    Green, E.P.; Edwards, A.J.; Mumby, P.J.

    1997-06-01

    Satellite (SPOT XS and Landsat TM) and airborne multispectral (CASI) imagery was acquired from the Turks and Caicos Islands, British West Indies. The descriptive resolution and accuracy of each image type is compared for two applications: mangrove habitat mapping and the measurement of mangrove canopy characteristics (leaf area index and canopy closure). Mangroves could be separated from non-mangrove vegetation to an accuracy of only 57% with SPOT XS data but better discrimination could be achieved with either Landsat TM or CASI (in both cases accuracy was >90%). CASI data permitted a more accurate classification of different mangrove habitats than was possible using Landsat TM. Nine mangrove habitats could be mapped to an accuracy of 85% with the high-resolution airborne data compared to 31% obtained with TM. A maximum of three mangrove habitats were separable with Landsat TM: the accuracy of this classification was 83%. Measurement of mangrove canopy characteristics is achieved more accurately with CASI than with either satellite sensor, but high costs probably make it a less cost-effective option. The cost-effectiveness of each sensor is discussed for each application.

  19. Monitoring and assessment of airborne Cladosporium Link and Alternaria Nées spores in Sivrihisar (Eskisehir), Turkey.

    PubMed

    Erkara, Ismuhan Potoglu; Ilhan, Semra; Oner, Setenay

    2009-01-01

    The spores of Cladosporium spp. and Alternaria spp., commonly described as the most allergenic spores, were collected by means of Durham gravimetric sampler from the Sivrihisar (Eskisehir) atmosphere throughout 2005 to 2006. The weekly variations in spores/cm(2) of Cladosporium and Alternaria were recorded. During this period, a total of 6,198 spores belonging to Cladosporium spp. and Alternaria spp. were recorded. Of these spores, 2,969 were identified in 2005 and 3,229 in 2006. While 69.55% of the total spores were those of Cladosporium spp., 30.45% were Alternaria spp. Relationships between airborne fungal spore presence and weather conditions were examined statistically. A Shapiro-Wilk test revealed that the airborne spores of Cladosporium spp. and Alternaria spp. had a normal distribution. Following this, Chi-square test, t test and Pearson correlation analysis were performed. The effects of temperature and relative humidity on the spore numbers of Cladosporium spp. and Alternaria spp. were significant according to the month in which they were collected (p < 0.01). The spore concentrations of each species reached to their highest levels in June 2006.

  20. Assessing potential impacts associated with contamination events in water distribution systems : a sensitivity analysis.

    SciTech Connect

    Davis, M. J.; Janke, R.; Taxon, T. N.

    2010-11-01

    An understanding of the nature of the adverse effects that could be associated with contamination events in water distribution systems is necessary for carrying out vulnerability analyses and designing contamination warning systems. This study examines the adverse effects of contamination events using models for 12 actual water systems that serve populations ranging from about 104 to over 106 persons. The measure of adverse effects that we use is the number of people who are exposed to a contaminant above some dose level due to ingestion of contaminated tap water. For this study the number of such people defines the impact associated with an event. We consider a wide range of dose levels in order to accommodate a wide range of potential contaminants. For a particular contaminant, dose level can be related to a health effects level. For example, a dose level could correspond to the median lethal dose, i.e., the dose that would be fatal to 50% of the exposed population. Highly toxic contaminants may be associated with a particular response at a very low dose level, whereas contaminants with low toxicity may only be associated with the same response at a much higher dose level. This report focuses on the sensitivity of impacts to five factors that either define the nature of a contamination event or involve assumptions that are used in assessing exposure to the contaminant: (1) duration of contaminant injection, (2) time of contaminant injection, (3) quantity or mass of contaminant injected, (4) population distribution in the water distribution system, and (5) the ingestion pattern of the potentially exposed population. For each of these factors, the sensitivities of impacts to injection location and contaminant toxicity are also examined. For all the factors considered, sensitivity tends to increase with dose level (i.e., decreasing toxicity) of the contaminant, with considerable inter-network variability. With the exception of the population distribution (factor 4

  1. Assessing the Impact of Source-Zone Remediation Efforts at the Contaminant-Plume Scale Through Analysis of Contaminant Mass Discharge

    PubMed Central

    Brusseau, M. L.; Hatton, J.; DiGuiseppi, W.

    2011-01-01

    The long-term impact of source-zone remediation efforts was assessed for a large site contaminated by trichloroethene. The impact of the remediation efforts (soil vapor extraction and in-situ chemical oxidation) was assessed through analysis of plume-scale contaminant mass discharge, which was measured using a high-resolution data set obtained from 23 years of operation of a large pump-and-treat system. The initial contaminant mass discharge peaked at approximately 7 kg/d, and then declined to approximately 2 kg/d. This latter value was sustained for several years prior to the initiation of source-zone remediation efforts. The contaminant mass discharge in 2010, measured several years after completion of the two source-zone remediation actions, was approximately 0.2 kg/d, which is ten times lower than the value prior to source-zone remediation. The time-continuous contaminant mass discharge data can be used to evaluate the impact of the source-zone remediation efforts on reducing the time required to operate the pump-and-treat system, and to estimate the cost savings associated with the decreased operational period. While significant reductions have been achieved, it is evident that the remediation efforts have not completely eliminated contaminant mass discharge and associated risk. Remaining contaminant mass contributing to the current mass discharge is hypothesized to comprise poorly-accessible mass in the source zones, as well as aqueous (and sorbed) mass present in the extensive lower-permeability units located within and adjacent to the contaminant plume. The fate of these sources is an issue of critical import to the remediation of chlorinated-solvent contaminated sites, and development of methods to address these sources will be required to achieve successful long-term management of such sites and to ultimately transition them to closure. PMID:22115080

  2. Assessing the impact of source-zone remediation efforts at the contaminant-plume scale through analysis of contaminant mass discharge.

    PubMed

    Brusseau, M L; Hatton, J; DiGuiseppi, W

    2011-11-01

    The long-term impact of source-zone remediation efforts was assessed for a large site contaminated by trichloroethene. The impact of the remediation efforts (soil vapor extraction and in-situ chemical oxidation) was assessed through analysis of plume-scale contaminant mass discharge, which was measured using a high-resolution data set obtained from 23 years of operation of a large pump-and-treat system. The initial contaminant mass discharge peaked at approximately 7kg/d, and then declined to approximately 2kg/d. This latter value was sustained for several years prior to the initiation of source-zone remediation efforts. The contaminant mass discharge in 2010, measured several years after completion of the two source-zone remediation actions, was approximately 0.2kg/d, which is ten times lower than the value prior to source-zone remediation. The time-continuous contaminant mass discharge data can be used to evaluate the impact of the source-zone remediation efforts on reducing the time required to operate the pump-and-treat system, and to estimate the cost savings associated with the decreased operational period. While significant reductions have been achieved, it is evident that the remediation efforts have not completely eliminated contaminant mass discharge and associated risk. Remaining contaminant mass contributing to the current mass discharge is hypothesized to comprise poorly accessible mass in the source zones, as well as aqueous (and sorbed) mass present in the extensive lower-permeability units located within and adjacent to the contaminant plume. The fate of these sources is an issue of critical import to the remediation of chlorinated-solvent contaminated sites, and development of methods to address these sources will be required to achieve successful long-term management of such sites and to ultimately transition them to closure.

  3. Geoelectric assessment of soil properties modification due to underground water contamination

    NASA Astrophysics Data System (ADS)

    Chitea, F.; Ioane, D.; Georgescu, P.; Mezincescu, M.

    2009-04-01

    Geophysical investigations, including resistivity and conductivity measurements, have been carried out in an agricultural area with variations of crop growth, located in the vicinity of the Petrobrazi oil refinery, Romania. The scientific project was devoted to the geoelectric assessment of soil and underground water contamination with oil derived products, based on the physical properties modification due to high resistivity contaminants. The shallow geological structure consists of soil (1 m), loess (0.5 m), sandy gravels (20 m) and clay, the oil contaminants being displaced horizontally by the aquifer dynamics with ca 100 m/year at a mean depth of 5 m, at the limit between the vadose and saturated zones. Due to sudden increase of underground contaminantion during technical accidents within the refinery, when the contaminant height above the aquifer reached 4.5 m, and oscilations of water table level associated with seasonal high precipitation regime, the geological formations within the vadose zone were upward polluted. More of that, due to capillarity processes developed on more then 70 years of industrial activity, this upward contamination affected also the soil layer. Results of 3D multielectrode resistivity measurements using the AGI SuperSting showed significant variations of this physical parameter between the surface and 1 m depth. The southern sector, affected by high contamination at the aquifer depth displays high resistivity values, the highest geoelectric anomalies being interpreted as small areas where oil derived products accumulated as a consequence of vertical migration. The soil of the southern sector is characterised by low resistivity values, suggesting that upward contamination processes were much weaker. In the area surveyed with the multielectrode system, conductivity measurements were carried out using a high resolution conductivity meter. Variations of soil quality between the northern sector and the southern one have been observed also

  4. Assessment and modelling of heavy metal contamination from Madneuli open-pit mine, Georgia

    NASA Astrophysics Data System (ADS)

    Tchelidze, T.; Melikadze, G.; Leveinen, J.; Kaija, J.; Kumpalainen, S.

    2003-04-01

    Acid mine drainage from banked waste rocks (150 million m^3) and sulfide ore tailings of the Madneuli Cu-Au open-pit mine have created major environmental pollution problem in Bolnisi district, Georgia. Intensive leaching of exposed rocks and direct discharge of mine waters to nearby watercourses have lead to strong heavy metal pollution of groundwater and Rivers Kazretula, Poladauri and Mashavera. Increased concentrations of Cu, Zn, Pb, Ni, Mn, Cr, Cd and Hg exceeding maximum permissible values by 3-2000 times, are registered almost everywhere. Polluted surface waters are used intensively for irrigation. Besides, contaminated groundwater is pumped for irrigation and drinking water supply in alluvial deposits along the rivers. Because the spread of contamination is a slow process, the adverse health effects may not yet have emerged in the investigation area. The transport modelling was used in the framework of risk assessment to estimate the direction, rate and extent of chemical migration in the contaminated site in order to support environmental management and decisionmaking involving identification of high-risk areas, protection from pollutants, and planning of remediation work. Geochemical and contamination transport modelling conducted in this study suggest that the present contamination levels will eventually reach the total investigation area causing serious health risks to the local population in long terms. Mineral lifetime estimates suggest that the contamination might continue for centuries with current pollution loads. Furthermore, geochemical modelling showed that there is no reason to expect the natural attenuation of the contamination. The potential impacts of preventive actions were studied by preparing a model scenario where the present heavy metal contamination level was lowered to 0.1 mg/l in two streams entering the model area. The model results suggest that within 5 years, already significant reduction of concentrations can be reached. The

  5. Risk assessment for dioxin contamination at Midland, Michigan (second edition). Final report

    SciTech Connect

    Nisbet, I.C.T.; Mendez, W.M.; Phillips, W.; Barnes, D.G.

    1988-04-01

    Results are presented of a comprehensive, multi-media, human-health risk assessment of the contamination in the Midland, Michigan, area with 2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD, and related compounds (dioxin) resulting primarily from past releases from the Dow Chemical Company's Michigan Division plant. The risk assessment follows USEPA's published guidelines for carcinogen risk assessment and exposure assessment. An exposure-assessment section summarizes the available environmental-monitoring data for the Midland area and derives estimated human intakes of dioxin for a number of scenarios based upon exposure of the local population to ambient air, drinking water, soil, and fish. Finally, a risk-characterization section combines the dose response and exposure information to determine estimated probabilities of adverse health effects for the scenarios considered.

  6. Assessment of the CALIPSO Lidar 532 nm Attenuated Backscatter Calibration Using the NASA LaRC Airborne High Spectral Resolution Lidar

    NASA Technical Reports Server (NTRS)

    Rogers, Raymond R.; Hostetler, Chris A.; Hair, Johnathan W.; Ferrare, Richard A.; Liu, Zhaoyan; Obland, Michael D.; Harper, David B.; Cook, Anthony L.; Powell, Kathleen A.; Vaughan, Mark A.; Winker, David M.

    2011-01-01

    The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) spacecraft has provided global, high-resolution vertical profiles of aerosols and clouds since it became operational on 13 June 2006. On 14 June 2006, the NASA Langley Research Center (LaRC) High Spectral Resolution Lidar (HSRL) was deployed aboard the NASA Langley B-200 aircraft for the first of a series of 86 underflights of the CALIPSO satellite to provide validation measurements for the CALIOP data products. To better assess the range of conditions under which CALIOP data products are produced, these validation flights were conducted under both daytime and nighttime lighting conditions, in multiple seasons, and over a large range of latitudes and aerosol and cloud conditions. This paper presents a quantitative assessment of the CALIOP 532 nm calibration (through the 532 nm total attenuated backscatter) using an internally calibrated airborne HSRL underflight data and is the most extensive study of CALIOP 532 nm calibration. Results show that average HSRL and CALIOP 532 nm total attenuated backscatter agree on average within 2.7% +/- 2.1% (CALIOP lower) at night and within 2.9 % +/- 3.9% (CALIOP lower) during the day., demonstrating the accuracy of the CALIOP 532 nm calibration algorithms. Additionally, comparisons with HSRL show consistency of the CALIOP calibration before and after the laser switch in 2009 as well as improvements in the daytime version 3 calibration scheme compared with the version 2 calibration scheme. Potential systematic uncertainties in the methodology relevant to validating satellite lidar measurements with an airborne lidar system are discussed and found to be less than 3.7% for this validation effort with HSRL. Results from this study are also compared to those from prior assessments of CALIOP calibration and attenuated backscatter.

  7. Improvement of modelling capabilities for assessing urban contamination : The EMRAS Urban Remediation Working Group.

    SciTech Connect

    Thiessen, K. M.; Batandjieva, B.; Andersson, K. G.; Arkhipov, A.; Charnock, T. W.; Gallay, F.; Gaschak, S.; Golikov, V.; Hwang, W. T.; Kaiser, J. C.; Kamboj, S.; Steiner, M.; Tomas, J.; Trifunovic, D.; Yu, C.; Ziemer, R. L.; Zlobenko, B.; Environmental Science Division; SENES Oak Ridge; IAEA; Riso National Lab.; Chernobyl Center for Nuclear Safety; Health Protection Agency; IRSN; Inst. of Radiation Hygene of the Ministry of Public Health, Russian Federation; KAERI, Republic of Korea; GSF, Germany; BfS, Germany; CPHR, Cuba; State Office for Radiation Protection, Croatia; AECL, Canada; National Academy of Science, Ukraine

    2008-01-01

    The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modeling for Radiation Safety (EMRAS) programme was established to improve modeling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.

  8. Can airborne ultrasound monitor bubble size in chocolate?

    NASA Astrophysics Data System (ADS)

    Watson, N.; Hazlehurst, T.; Povey, M.; Vieira, J.; Sundara, R.; Sandoz, J.-P.

    2014-04-01

    Aerated chocolate products consist of solid chocolate with the inclusion of bubbles and are a popular consumer product in many countries. The volume fraction and size distribution of the bubbles has an effect on their sensory properties and manufacturing cost. For these reasons it is important to have an online real time process monitoring system capable of measuring their bubble size distribution. As these products are eaten by consumers it is desirable that the monitoring system is non contact to avoid food contaminations. In this work we assess the feasibility of using an airborne ultrasound system to monitor the bubble size distribution in aerated chocolate bars. The experimental results from the airborne acoustic experiments were compared with theoretical results for known bubble size distributions using COMSOL Multiphysics. This combined experimental and theoretical approach is used to develop a greater understanding of how ultrasound propagates through aerated chocolate and to assess the feasibility of using airborne ultrasound to monitor bubble size distribution in these systems. The results indicated that a smaller bubble size distribution would result in an increase in attenuation through the product.

  9. Environmental risk assessment of metals contaminated soils at silvermines abandoned mine site, Co Tipperary, Ireland.

    PubMed

    Aslibekian, Olga; Moles, Richard

    2003-06-01

    A centuries long history of mining and mineral processing has resulted in elevated Cd, Pb and Zn soil concentrations in the vicinity of the Silvermines abandoned mine site (AMS), Co. Tipperary, Ireland. A process for preliminary evaluation of environmental risk was developed and implemented. Potential pathways of metal compound transport and deposition were mapped and used to optimise the subsequent site investigation. Elevated soil metals are shown to be predominantly in areas where metal deposition in soil is associated with water related pathways (surface runoff, seasonal groundwater seepage and floodplains). Extensive areas of soil in the surrounding district are classified as contaminated on the basis of Cd, Pb and Zn concentrations, both total and potential bioavailable (EDTA-extractable). The most affected areas, with metal concentrations in soil comparable with that within the AMS, were floodplains located 2-3 km downstream from the site. Assessment of the sequential effects on grass and grazing animals indicates that Pb poses the greatest risk due to its high toxicity and high concentrations in soil (more than 10,000 mg kg-1). Within floodplain areas grazing cattle may intake a lethal dose of Pb. On the basis of the investigation an approach to risk assessment was developed which allowed quantified assessment of the risks related to individual metals, areas of contamination and contamination targets.

  10. Improving Modeling of Iodine-129 Groundwater Contamination Plumes Using the System Assessment Capability

    SciTech Connect

    Dirkes, J.; Nichols, W.E.; Wurstner, S.K.

    2004-01-01

    Years of production of radioactive materials at the Hanford Site in southeastern Washington State has resulted in contamination of surface, subsurface, and surface water environments. Cleanup of the site has been aided by various tools, including computer software used to predict contaminant migration in the future and estimate subsequent impacts. The System Assessment Capability (SAC) is a total systems tool designed to simulate the movement of contaminants from all waste sites at Hanford through the vadose zone, the unconfined aquifer, and the Columbia River. Except for iodine-129, most of the contaminants modeled by SAC have acceptably matched field measurements. The two most likely reasons for the inconsistency between the measured field data and SAC modeled predictions are an underestimated inventory and an overestimated sorption value (Kd). Field data tend to be point measurements taken from near the surface of the unconfined aquifer. Thus, the depth of the iodine-129 contamination plume on the site is not well characterized. Geostatistical analyses of the measured data were conducted to determine the mass of iodine-129 for four assumed plume depths within the unconfined aquifer. Several simulations for two different Kd’s using the initial SAC inventory were run to determine the effect of an overestimated sorption value on SAC modeled predictions. The initial SAC inventory was then increased for the two different Kd’s to determine the influence of an underestimated inventory on SAC modeled predictions. It was found that evidence for both an underestimated inventory and for an overestimated sorption value for iodine-129 exist. These results suggest that the Kd for iodine-129 should be reevaluated and that a more complete inventory must be generated in order to more accurately model iodine-129 groundwater contamination plumes that match available field data.

  11. Contaminants assessment in the coral reefs of Virgin Islands National Park and Virgin Islands Coral Reef National Monument

    USGS Publications Warehouse

    Bargar, Timothy A.; Garrison, Virginia H.; Alvarez, David A.; Echols, Kathy

    2013-01-01

    Coral, fish, plankton, and detritus samples were collected from coral reefs in Virgin Islands National Park (VIIS) and Virgin Islands Coral Reef National Monument (VICR) to assess existing contamination levels. Passive water sampling using polar organic chemical integrative samplers (POCIS) and semi-permeable membrane devices found a few emerging pollutants of concern (DEET and galaxolide) and polynuclear aromatic hydrocarbons. Very little persistent organic chemical contamination was detected in the tissue or detritus samples. Detected contaminants were at concentrations below those reported to be harmful to aquatic organisms. Extracts from the POCIS were subjected to the yeast estrogen screen (YES) to assess potential estrogenicity of the contaminant mixture. Results of the YES (estrogen equivalency of 0.17–0.31 ng/L 17-β-estradiol) indicated a low estrogenicity likelihood for contaminants extracted from water. Findings point to low levels of polar and non-polar organic contaminants in the bays sampled within VICR and VIIS.

  12. Contaminants assessment in the coral reefs of Virgin Islands National Park and Virgin Islands Coral Reef National Monument.

    PubMed

    Bargar, Timothy A; Garrison, Virginia H; Alvarez, David A; Echols, Kathy R

    2013-05-15

    Coral, fish, plankton, and detritus samples were collected from coral reefs in Virgin Islands National Park (VIIS) and Virgin Islands Coral Reef National Monument (VICR) to assess existing contamination levels. Passive water sampling using polar organic chemical integrative samplers (POCIS) and semi-permeable membrane devices found a few emerging pollutants of concern (DEET and galaxolide) and polynuclear aromatic hydrocarbons. Very little persistent organic chemical contamination was detected in the tissue or detritus samples. Detected contaminants were at concentrations below those reported to be harmful to aquatic organisms. Extracts from the POCIS were subjected to the yeast estrogen screen (YES) to assess potential estrogenicity of the contaminant mixture. Results of the YES (estrogen equivalency of 0.17-0.31 ng/L 17-β-estradiol) indicated a low estrogenicity likelihood for contaminants extracted from water. Findings point to low levels of polar and non-polar organic contaminants in the bays sampled within VICR and VIIS.

  13. Assessment of coastal storm impacts on contaminant body burdens of oysters collected from the Gulf of Mexico.

    PubMed

    Apeti, Dennis A; Lauenstein, Gunnar G; Christensen, John D; Johnson, Edward W; Mason, Andrew

    2011-10-01

    This study evaluated changes in oyster tissue contaminant levels following North Atlantic tropical cyclones to determine if changes in contaminant concentrations were predictable. The basis for this study was analysis of coastal chemical contaminant data from the National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends Mussel Watch Program and NOAA's National Weather Service storm track data. The tendency for contaminant (metals and organic compounds) body burdens to increase or decrease in oyster tissue after a storm was assessed using contingency and correspondence analyses. Post-storm contaminant levels in oysters revealed a consistent pattern of distribution, which could be described as follows: (1) most of the organic contaminants stay within their long-term concentration ranges, (2) very few organic contaminants decreased, and (3) metals overwhelmingly tend to increase.

  14. Integrated assessment of metal contamination in sediments from two tropical estuaries.

    PubMed

    Krull, Marcos; Abessa, Denis M S; Hatje, Vanessa; Barros, Francisco

    2014-08-01

    In order to evaluate if sediment metal contamination is responsible for benthic degradation and identify possible reference sites in Todos os Santos Bay (TSB), comparisons between a highly impacted (Subaé) and less impacted (Jaguaripe) estuarine systems were made based on (i) field assessment of macrobenthic assemblage, (ii) sediment metal concentrations and (iii) chronic toxicity test with the tropical copepod Nitokra sp. Data were integrated by multivariate analysis (BIOENV and PCA) and the ratio-to-mean (RTMe) approach. Estuaries were divided into four different salinity zones to avoid misclassification of benthic conditions. Salinity was the main variable correlated to the benthic distribution in both estuaries, indicating that categories based on salinity features seem to be suitable in TSB. Correspondence among lines of evidence differed in low and high metal contaminated systems. Chronic toxicity was found along both the entire systems, being considerably higher in Jaguaripe. However, there was no clear evidence of metal contamination and benthic alteration in most stations of Jaguaripe. Although the concentrations of Sr and Cu were correlated to the benthic assemblage in Jaguaripe, it is unlikely that toxicity has been caused by these elements. The benthic assemblage distribution of Jaguaripe seems to be rather related to natural stressful conditions of transitional waters. Even though the Jaguaripe estuary might not be pristine, it can be used as a reference estuary for benthic assessment in TSB. Regarding the Subaé estuary, toxicity and Zn were also correlated to the benthic assemblage and most stations showed signs of benthic alteration and metal contamination. All lines of evidence were in agreement providing evidences that metal contamination might be responsible for benthic degradation in Subaé.

  15. Assessment of Groundwater Vulnerability for Antropogenic and Geogenic Contaminants in Subwatershed

    NASA Astrophysics Data System (ADS)

    Ko, K.; Koh, D.; Chae, G.; Cheong, B.

    2007-12-01

    Groundwater is an important natural resource that providing drinking water to more than five million people in Korea. Nonpoint source nitrate was frequently observed contaminant and the investigation result for small potable water supply system that mainly consisted of 70 percent groundwater showed that about 5 percent of water samples exceeded potable water quality standards of Korea. The geogenic contanminants such as arsenic and fluoride also frequently observed contaminants in Korea. In order to protect groundwater and to supply safe water to public, we need to assess groundwater vulnerability and to know the cause of occurrence of contaminants. To achieve this goal, we executed groundwater investigation and assessment study for Keumsan subwatershed with 600km2 in Keum-river watershed. The geostatistical and GIS technique were applied to map the spatial distribution of each contaminants and to calculate vulnerability index. The results of logistic regression for nitrate indicated the close relationship with land use. The results of hydrogeochemical analyses showed that nitrates in groundwater are largely influenced by land use and had high values in granitic region with dense agricultural field and resident. The high nitrates are closely related to groundwater of greenhouse area where large amount of manure and fertilizer were usually introduced in cultural land. The soil in granitic region had high contents of permeable sand of weathered products of granite that play as a role of pathway of contaminants in agricultural land and resident area. The high values of bicarbonate are originated from two sources, limestone dissolution of Ogcheon belt and biodegradation organic pollutants from municipal wastes in granitic region with dense agriculture and residence. It is considered that the anomalous distribution of arsenic and fluoride is related to limestone and metasedimentry rock of Ogcheon belt with high contents of sulfide minerals and F bearing minerals. The

  16. A spatial risk assessment methodology to support the remediation of contaminated land.

    PubMed

    Carlon, Claudio; Pizzol, Lisa; Critto, Andrea; Marcomini, Antonio

    2008-04-01

    When soil and groundwater contaminations occur over large areas, remediation measures should be spatially prioritized on the basis of the risk posed to human health and in compliance with technological and budget constraints. Within this scope, the application of human health risk assessment algorithms in a spatially resolved environment raises a number of methodological and technical complexities. In this paper, a methodology is proposed and applied in a case study to support the entire formulation process of remediation plans, encompassing hazard assessment, exposure assessment, risk characterisation, uncertainty assessment and allocation of risk reduction measures. In the hazard assessment, it supports the selection of Contaminants of Concern (CoC) with regard to both their average concentrations and peak concentrations, i.e. hot spots. In the exposure assessment, it provides a zoning of the site based on the geostatistical mapping of contaminant. In the risk characterisation, it generates vector maps of Risk Factors on the basis of the risk posed by multiple substances and allows the interrogation of most relevant CoC and exposure pathways for each zone of the site. It also supports the Monte Carlo based probabilistic estimation of the Risk Factors and generates maps of the associated uncertainty. In the risk reduction phase, it supports the formulation of remediation plans based on the stepwise spatial allocation of remediation interventions and the on-time simulation of risk reduction performances. The application of this methodology is fully supported by an easy-to-use and customized Geographical Information System and does not require high expertise for interpretation. The proposed methodology is the core module of a Decision Support System (DSS) that was implemented in the DESYRE software aimed at supporting the risk-based remediation of megasites.

  17. Predictors of airborne endotoxin concentrations in inner city homes.

    PubMed

    Mazique, D; Diette, G B; Breysse, P N; Matsui, E C; McCormack, M C; Curtin-Brosnan, J; Williams, D L; Peng, R D; Hansel, N N

    2011-05-01

    Few studies have assessed in home factors which contribute to airborne endotoxin concentrations. In 85 inner city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36-42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483

  18. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Grand Junction, Colorado

    SciTech Connect

    Not Available

    1994-06-01

    This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site Near Grand Junction, Colorado evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site. This risk assessment follows an approach outlined by the EPA. the first step is to evaluate ground water data collected from monitor wells at the site. Evaluation of these data showed that the contaminants of potential concern in the ground water are arsenic, cadmium, cobalt, fluoride, iron, manganese, molybdenum, nickel, sulfate, uranium, vanadium, zinc, and radium-226. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if they drank from a well installed in the contaminated ground water at the former processing site.

  19. Assessment of in-situ bioremediation at a refinery waste-contaminated site and an aviation gasoline contaminated site.

    PubMed

    Bhupathiraju, Vishvesh K; Krauter, Paula; Holman, Hoi-Ying N; Conrad, Mark E; Daley, Paul F; Templeto, Alexis S; Hunt, James R; Hernandez, Mark; Alvarez-Cohen, Lisa

    2002-01-01

    A combination of geochemical, microbiological and isotopic methods were used to evaluate in-situ bioremediation of petroleum hydrocarbons at one site contaminated with refinery waste and a second site contaminated with aviation gasoline at Alameda Point, California. At each site, geochemical and microbiological characteristics from four locations in the contaminated zone were compared to those from two uncontaminated background locations. At both sites, the geochemical indicators of in-situ biodegradation included depleted soil gas and groundwater oxygen, elevated groundwater alkalinity, and elevated soil gas carbon dioxide and methane in the contaminated zone relative to the background. Radiocarbon content of methane and carbon dioxide measured in soil gas at both sites indicated that they were derived from hydrocarbon contaminant degradation. Direct microscopy of soil core samples using cell wall stains and activity stains, revealed elevated microbial numbers and enhanced microbial activities in contaminated areas relative to background areas, corroborating geochemical findings. While microbial plate counts and microcosm studies using soil core samples provided laboratory evidence for the presence of some microbial activity and contaminant degradation abilities, they did not correlate well with either contaminant location, geochemical, isotopic, or direct microscopy data.

  20. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah

    SciTech Connect

    Not Available

    1994-09-01

    This document evaluates potential impacts to public health and the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1989 by the US DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, UMTRA Project is evaluating ground water contamination in this risk assessment.

  1. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Slick Rock, Colorado. Revision 1

    SciTech Connect

    1995-09-01

    Two UMTRA (Uranium Mill Tailings Remedial Action) Project sites are near Slick Rock, Colorado: the North Continent site and the Union Carbide site. Currently, no one uses the contaminated ground water at either site for domestic or agricultural purposes. However, there may be future land development. This risk assessment evaluates possible future health problems associated with exposure to contaminated ground water. Since some health problems could occur, it is recommended that the contaminated ground water not be used as drinking water.

  2. Assessing spaceborne lidar detection and characterization of aerosols near clouds using coincident airborne lidar and other measurements

    NASA Astrophysics Data System (ADS)

    Kacenelenbogen, M. S.; Redemann, J.; Russell, P. B.; Vaughan, M.; Omar, A. H.; Burton, S. P.; Rogers, R.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.

    2011-12-01

    The objectives are to 1) evaluate potential shortcomings in the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol height detection concerning specific biomass burning smoke events informed by airborne High Spectral Resolution Lidar (HSRL) in different cloud environments and 2) study the lidar-derived atmospheric parameters in the vicinity of clouds for the cases where smoke is within or above clouds. In the case of light absorbing aerosols like biomass burning smoke, studies show that the greater the cloud cover below the aerosols, the more likely the aerosols are to heat the planet. An accurate aerosol height assumption is also crucial to a correct retrieval of aerosol chemical composition from passive space-based measurements (through the Single Scattering Albedo (SSA) and aerosol absorption coefficient, as exemplified by aerosol retrievals using the passive Ozone Monitoring Instrument (OMI)). Strong smoke events are recognized as very difficult to quantify from space using passive (MODIS, OMI etc...) or active (CALIOP) satellite sensors for different reasons. This study is performed through (i) the selection of smoke events with coincident CALIOP and airborne HSRL aerosol observations, with smoke presence determined according to the HSRL aerosol classification data, (ii) the order of such events by range of HSRL aerosol optical depth, total color ratio and depolarization ratio (the latter two informing on the size and shape of the particles) and the evaluation of CALIOP's detection, classification and retrieval performance for each event, (iii) the study of the HSRL (or CALIOP when available) atmospheric parameters (total color ratio, volume depolarization ratio, mean attenuated backscatter) in the vicinity of clouds for each smoke event.

  3. Transport of Aquatic Contaminant and Assessment of Radioecological Exposure with Spatial and Temporal Effects

    NASA Astrophysics Data System (ADS)

    Feng, Ying

    1995-01-01

    A comprehensive study of the radioecological exposure assessment for a contaminated aquatic ecosystem has been performed in this dissertation. The primary objectives of this research were to advance the understanding of radiation exposure in nature and to increase current capabilities for estimating aquatic radiation exposure with the consideration of spatial and temporal effect in nature. This was accomplished through the development of a two-dimensional aquatic exposure assessment framework and by applying the framework to the contaminated Chernobyl cooling lake (pond). This framework integrated spatial and temporal heterogeneity effects of contaminant concentration, abundance and distribution of ecosystem populations, spatial- and temporal-dependent (or density-dependent) radionuclide ingestion, and alternative food web structures. The exposure model was built on the population level to allow for the integration of density dependent population regulation into the exposure assessment. Plankton population dynamics have been integrated into the hydrodynamic-transport model to determine plankton biomass density changes and distributions. The distribution of contaminant in water was also calculated using a hydrodynamic-transport model. The significance of adding spatial and temporal effects, spatial and temporal related ecological functions, and hydrodynamics in the exposure assessment was illustrated through a series of case studies. The results suggested that the spatial and temporal heterogeneity effects of radioactive environments were substantial. Among the ecological functions considered, the food web structure was the most important contributor to the variations of fish exposure. The results obtained using a multiple prey food web structure differed by a factor of 20 from the equilibrium concentration, and by a factor of 2.5 from the concentration obtained using a single-prey food web. Impacts of changes in abundance and distribution of biomass on contaminant

  4. An assessment of IceBridge airborne data quality over Arctic sea ice via comparison with in situ measurements gathered in the Beaufort Sea

    NASA Astrophysics Data System (ADS)

    Newman, T.; Farrell, S. L.; Richter-Menge, J.; Connor, L. N.; Kurtz, N. T.; Elder, B. C.

    2012-12-01

    The Arctic sea ice pack has experienced rapid changes over the last decade with well documented losses in ice extent. More recently, observations suggest a decline in sea ice thickness leading to a basin-wide loss of ice volume. Fundamental to our capabilities to monitor and forecast these changes are observations from airborne and satellite-based laser and radar altimeters. The accurate mapping of sea ice thickness, using these instruments, requires the largest identified contributors to thickness errors to be better constrained: namely the uncertainties in sea ice freeboard and snow depth. To quantify these errors a 9 km long survey line was established in March 2011 near the US Navy ICEX2011 ice camp in the Beaufort Sea. The survey line was strategically located to cover a wide range of Arctic ice types: refrozen leads, deformed and undeformed first year ice, and multiyear ice. Survey measurements included estimates of ice thickness using the EM31 (an electromagnetic ground-conductivity meter), direct measurements of sea ice freeboard, snow thickness using a snow magnaprobe and snow pits to characterize the snow layer. The primary goal of the ICEX experiment was to provide an assessment of the remaining errors associated with aircraft-derived snow depth and sea ice thickness as a function of ice type. An Operation IceBridge (OIB) aircraft overflight of the survey line was conducted on the 23rd March 2011 from an altitude of ~465 m. The OIB instrument suite on the aircraft included: the Ku-band radar altimeter (13-17 GHz), the snow radar (2-8 GHz), the Airborne Topographical Mapper (ATM) laser altimeter and the Digital Mapping System (DMS) digital camera, which together provide estimates of sea ice freeboard, thickness, surface roughness and snow depth. We present a new methodology for analyzing the snow radar data for the extraction and estimation of snow depth utilizing a novel wavelet-based layer-picking technique. The snow depths derived from the snow radar

  5. Preliminary hydrogeologic assessment of a ground-water contamination area in Wolcott, Connecticut

    USGS Publications Warehouse

    Stone, J.R.; Casey, G.D.; Mondazzi, R.A.; Frick, T.W.

    1997-01-01

    Contamination of ground water by volatile organic compounds and inorganic constituents has been identified at a number of industrial sites in the Town of Wolcott, Connecticut. Contamination is also present at a municipal landfill in the City of Waterbury that is upgradient from the industrial sites in the local ground-water-flow system. The study area, which lies in the Western Highlands of Connecticut, is in the Mad River Valley, a tributary to the Naugatuck River. Geohydrologic units (aquifer materials) include unconsolidated glacial sediments (surficial materials) and fractured crystalline (metamorphic) bedrock. Surficial materials include glacial till, coarse-grained andfine-grained glacial stratified deposits, and postglacial floodplain alluvium and swamp deposits. The ground-water-flow system in the surficial aquifer is complex because the hydraulic properties of the surficial materials are highly variable. In the bedrock aquifer, ground water moves exclusively through fractures. Hydrologic characteristics of the crystalline bedrock-degree of confinement, hydraulic conductivity, storativity, and porosity-are poorly defined in the study area. Further study is needed to adequately assess ground-water flow and contaminant migration under current or past hydrologic conditions. All known water-supply wells in the study area obtain water from the bedrock aquifer. Twenty households in a hillside residential area on Tosun Road currently obtain drinking water from private wells tapping the bedrock aquifer. The extent of contamination in the bedrock aquifer and the potential for future contamination from known sources of contamination in the surficial aquifer is of concern to regulatory agencies. Previous investigations have identified ground-water contamination by volatile organic compounds at the Nutmeg Valley Road site area. Contamination has been associated with on-site disposal of heavy metals, chlorinated and non-chlorinated volatile organic compounds, and

  6. Assessment of potential groundwater contamination sources in a wellhead protection area.

    PubMed

    Harman, W A; Allan, C J; Forsythe, R D

    2001-07-01

    Determining the human health dangers from potential contamination sources, within a wellhead protection area (WHPA), requires that a risk analysis be undertaken. In this study, a desktop geographic information system and spreadsheet software are used to implement an EPA risk screening methodology for WHPAs called 'Managing Ground Water Contamination Sources in Wellhead Protection Areas--A Priority Setting Approach'. The methodology was applied to a WHPA in Gaston County, North Carolina. Results indicate that the risk of well contamination from an interstate highway and gas station with old steel underground storage tanks were comparatively high. Medium risks included a thoroughfare and highway, while low risks were assigned to machine shops, a body shop, septic systems and a gas station with new underground storage tanks and secondary containment. A sensitivity analyses of the Priority Setting Approach indicated that risk scores were extremely sensitive to hydrogeologic variables such as hydraulic conductivity. It is recommended that risk assessors utilize a range of hydrogeologic parameters to assess overall risk from each potential contamination source.

  7. Prevalence of microbiological contaminants in groundwater sources and risk factor assessment in Juba, South Sudan.

    PubMed

    Engström, Emma; Balfors, Berit; Mörtberg, Ulla; Thunvik, Roger; Gaily, Tarig; Mangold, Mikael

    2015-05-15

    In low-income regions, drinking water is often derived from groundwater sources, which might spread diarrheal disease if they are microbiologically polluted. This study aimed to investigate the occurrence of fecal contamination in 147 improved groundwater sources in Juba, South Sudan and to assess potential contributing risk factors, based on bivariate statistical analysis. Thermotolerant coliforms (TTCs) were detected in 66% of the investigated sources, including 95 boreholes, breaching the health-based recommendations for drinking water. A significant association (p<0.05) was determined between the presence of TTCs and the depth of cumulative, long-term prior precipitation (both within the previous five days and within the past month). No such link was found to short-term rainfall, the presence of latrines or damages in the borehole apron. However, the risk factor analysis further suggested, to a lesser degree, that the local topography and on-site hygiene were additionally significant. In summary, the analysis indicated that an important contamination mechanism was fecal pollution of the contributing groundwater, which was unlikely due to the presence of latrines; instead, infiltration from contaminated surface water was more probable. The reduction in fecal sources in the environment in Juba is thus recommended, for example, through constructing latrines or designating protection areas near water sources. The study results contribute to the understanding of microbiological contamination of groundwater sources in areas with low incomes and high population densities, tropical climates and weathered basement complex environments, which are common in urban sub-Saharan Africa.

  8. Reducing uncertainty in ecological risk assessment: The pros of measuring contaminant exposures

    SciTech Connect

    Burris, J.A.; Pease, A.

    1995-12-31

    Wildlife species (mammals, birds and reptiles) are primarily exposed to contamination in soils via ingestion of food. Uncertainties in risk analyses for this pathway are largely associated with the estimation of the amount of contamination in food items. The benefits of measuring contaminant concentrations in food items are examined based on comparison of risk results with and without measurements of exposure. At two hazardous waste sites, plants and earthworms were analyzed for metals and organics. Site-specific bioaccumulation factors (BAFs) were calculated and compared to literature reported values. In general, the metals concentrations in plant samples were higher than those predicted by literature values with the exception of cadmium and copper. Metal concentrations measured in invertebrates (worms) were lower than those predicted by literature values with the exception of arsenic. Literature BAFs did not adequately predict concentrations of barium, mercury or copper in invertebrate tissue. In the ecological risk assessments for both of the sites, if site-specific measurements were used, risks for wildlife species were not predicted. However if literature BAF values were used, unacceptable risks were predicted. The higher estimates of risks were associated with overestimates of dietary exposures of lead, cadmium, chromium, copper and zinc. Measurement of contaminant exposures provided for a more realistic and cost-effective estimate of ecological risks. The effect of using the empirical data on the magnitude of risks were evaluated including decisions concerning remediation. A cost-benefit analysis will be provided comparing the costs of measurement of exposures versus remediation.

  9. Use of artificial oak log substrates to assess the impact of contaminants on soil macroinvertebrates

    SciTech Connect

    Henry, R.; Charters, D.W.

    1995-12-31

    Consideration of aquatic benthic macroinvertebrates can yield insight concerning the effects of chemical contamination on community structure and function. This approach has been used successfully to distinguish subtle changes in community response to water quality and watershed degradation. Analyses of this type however, has not been developed to the same extent for terrestrial soil macroinvertebrate communities. A number of factors, including sampling protocols and habitat variability, may inhibit efforts in this direction. An artificial substrate was developed that mimics a decaying oak log. These artificial logs are constructed of oak slats filled with various sized oak particles and measure approximately 7 cm x 7 cm x 30 cm. The substrates are deployed on the soil surface across a contaminant gradient and allowed to colonize. Following recovery, the logs are transported to a laboratory where they are disassembled, and the colonizers extracted for taxonomic, numeric, or other analyses. Since the artificial substrate community is a reflection of the endemic soil inhabitants, the results of this type of evaluation can be used in the assessment of ecological concerns associated with soil contamination. The practical and theoretical concerns of this method will be discussed along with the results of an initial trial at a metal contaminated site.

  10. Long-term assessment of natural attenuation: statistical approach on soils with aged PAH contamination.

    PubMed

    Ouvrard, Stéphanie; Chenot, Elodie-Denise; Masfaraud, Jean-François; Schwartz, Christophe

    2013-07-01

    Natural attenuation processes valorization for PAH-contaminated soil remediation has gained increasing interest from site owners. A misunderstanding of this method and a small amount of data available does not encourage its development. However, monitored natural attenuation (MNA) offers a valuable, cheaper and environmentally friendly alternative to more classical options such as physico-chemical treatments (e.g., chemical oxidation, thermal desorption). The present work proposes the results obtained during a long-term natural attenuation assessment of historically contaminated industrial soils under real climatic conditions. This study was performed after a 10 year natural attenuation period on 60 off-ground lysimeters filled with contaminated soils from different former industrial sites (coking industry, manufactured gas plants) whose initial concentration of PAH varied between 380 and 2,077 mg kg(-1). The analysed parameters included leached water characterization, soil PAH concentrations, evaluation of vegetation cover quality and quantity. Results showed a good efficiency of the PAH dissipation and limited transfer of contaminants to the environment. It also highlighted the importance of the fine soil fractions in controlling PAH reactivity. PAH dissipation through water leaching was limited and did not present a significant risk for the environment. This PAH water concentration appeared however as a good indicator of overall dissipation rate, thereby illustrating the importance of pollutant availability in predicting its degradation potential.

  11. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Shiprock, New Mexico. Revision 1

    SciTech Connect

    Not Available

    1994-04-01

    This baseline risk assessment at the former uranium mill tailings site near Shiprock, New Mexico, evaluates the potential impact to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an on-site disposal cell in 1986 through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. There are no domestic or drinking water wells in the contaminated ground water of the two distinct ground water units: the contaminated ground water in the San Juan River floodplain alluvium below the site and the contaminated ground water in the terrace alluvium area where the disposal cell is located. Because no one is drinking the affected ground water, there are currently no health or environmental risks directly associated with the contaminated ground water. However, there is a potential for humans, domestic animals, and wildlife to the exposed to surface expressions of ground water in the seeps and pools in the area of the San Juan River floodplain below the site. For these reasons, this risk assessment evaluates potential exposure to contaminated surface water and seeps as well as potential future use of contaminated ground water.

  12. Human health risk assessment in restoring safe and productive use of abandoned contaminated sites.

    PubMed

    Wcisło, Eleonora; Bronder, Joachim; Bubak, Anicenta; Rodríguez-Valdés, Eduardo; Gallego, José Luis R

    2016-09-01

    In Europe soil contamination has been recognized as a serious problem. The needs to remediate contaminated sites are not questionable, although the remediation actions are often hindered by their very high financial costs. On the other hand, the abandoned contaminated sites may have the potential for redevelopment and creating conditions appropriate for their productive reuse bringing social, economic and environmental benefits. The main concern associated with the contaminated sites is their potential adverse health impact. Therefore, in the process of contaminated site redevelopment the risk assessment and the subsequent risk management decisions will play a crucial role. The main objective of this study was to illustrate the role of the human health risk assessment (HRA) in supporting site remediation and reuse decisions. To exemplify the significance of the HRA process in this field the Nitrastur site, located in Asturias, Spain was used. Risks resulting from soil contamination with arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), mercury (Hg), zinc (Zn) and lead (Pb) were assessed under three potential future land use patterns: industrial, residential and recreational. The results of the study indicated that soil at the Nitrastur site might pose non-cancer and cancer risks to potential future receptors - industrial workers, residents and recreational users. Arsenic and lead are the main substances responsible for the health risk and the primary drivers of remedial decisions at the site. The highest total cancer risks were observed under the residential scenario, followed in descending order by the recreational and industrial ones. The remedial maps illustrate in which areas remediation activities are required, depending on a given land use pattern. The obtained results may be used to develop, analyse, compare and select the remedial options within the intended land use pattern. They may also be used to support the decisions concerning the

  13. Risk assessment of heavy metals and their source distribution in waters of a contaminated industrial site.

    PubMed

    Krishna, A Keshav; Mohan, K Rama

    2014-03-01

    Industrially contaminated sites with hazardous materials are a priority and urgent problem all over the world. Appropriate risk assessment is required to determine health risks associated with contaminated sites. The present study was conducted to investigate distribution of potentially hazardous, heavy metal (As, Cd, Cr, Cu, Ni, Pb and Zn) concentrations in surface and groundwater samples collected during summer (pre-monsoon) and winter (post-monsoon) seasons from an industrially contaminated site, Hyderabad, India, with potential source of metal contamination because of industrial effluents and usage of pesticides in agriculture. Heavy metal (HM) concentrations were analysed by using inductively coupled plasma-mass spectrometer and were compared with permissible limits set by the World Health Organisation. Data obtained was treated using multivariate statistical approaches like R-mode factor analysis (FA), principal component analysis, cluster analysis, geoaccumulation index, enrichment factor, contamination factor and the degree of contamination. Health risk assessment like chronic daily intake (CDI) and hazard quotient (HQ) were also calculated. Relatively high levels were noted in surface water with average concentrations during summer and winter seasons showing 16.13 and 11.83 for As, 7.91 and 1.64 for Cd, 88.33 and 32.90 for Cr, 58.11 and 28.26 for Cu, 53.62 and 69.96 for Ni, 173.8 and 118.6 for Pb, and 2,943 and 1,889 μg/L for Zn. While in groundwater, the mean metal levels during two seasons were 18.18 and 3.76 for As, 1.67 and 0.40 for Cd, 29.40 and 5.15 for Cr, 17.03 and 4.19 for Cu, 25.4 and 6.09 for Ni, 81.7 and 2.87 for Pb and 953 and 989 μg/L for Zn, respectively. FA identified two factors with cumulative loadings of F1-60.82 % and F2-76.55 % for pre-monsoon surface water and F1-48.75 % and F2-67.55 % for groundwater. Whereas, three factors with cumulative loadings of F1-39.13 %, F2-66.60 % and F3-81.01 % for post-monsoon surface water and F1

  14. Human health risk assessment in restoring safe and productive use of abandoned contaminated sites.

    PubMed

    Wcisło, Eleonora; Bronder, Joachim; Bubak, Anicenta; Rodríguez-Valdés, Eduardo; Gallego, José Luis R

    2016-09-01

    In Europe soil contamination has been recognized as a serious problem. The needs to remediate contaminated sites are not questionable, although the remediation actions are often hindered by their very high financial costs. On the other hand, the abandoned contaminated sites may have the potential for redevelopment and creating conditions appropriate for their productive reuse bringing social, economic and environmental benefits. The main concern associated with the contaminated sites is their potential adverse health impact. Therefore, in the process of contaminated site redevelopment the risk assessment and the subsequent risk management decisions will play a crucial role. The main objective of this study was to illustrate the role of the human health risk assessment (HRA) in supporting site remediation and reuse decisions. To exemplify the significance of the HRA process in this field the Nitrastur site, located in Asturias, Spain was used. Risks resulting from soil contamination with arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), mercury (Hg), zinc (Zn) and lead (Pb) were assessed under three potential future land use patterns: industrial, residential and recreational. The results of the study indicated that soil at the Nitrastur site might pose non-cancer and cancer risks to potential future receptors - industrial workers, residents and recreational users. Arsenic and lead are the main substances responsible for the health risk and the primary drivers of remedial decisions at the site. The highest total cancer risks were observed under the residential scenario, followed in descending order by the recreational and industrial ones. The remedial maps illustrate in which areas remediation activities are required, depending on a given land use pattern. The obtained results may be used to develop, analyse, compare and select the remedial options within the intended land use pattern. They may also be used to support the decisions concerning the

  15. Combustion aerosols formed during burning of radioactively contaminated materials: Experimental results

    SciTech Connect

    Halverson, M.A.; Ballinger, M.Y.; Dennis, G.W.

    1987-03-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of potential airborne releases. Radioactive aerosols generated by fires were investigated in experiments in which combustible solids and liquids were contaminated with radioactive materials and burned. Uranium in powder and liquid form was used to contaminate five fuel types: polychloroprene, polystyrene, polymethylmethacrylate, cellulose, and a mixture of 30% tributylphosphate (TBP) in kerosene. Heat flux, oxygen concentration, air flow, contaminant concentration, and type of ignition were varied in the experiments. The highest release (7.1 wt %) came from burning TBP/kerosene over contaminated nitric acid. Burning cellulose contaminated with uranyl nitrate hexahydrate liquid gave the lowest release (0.01 wt %). Rate of release and particle size distribution of airborne radioactive particles were highly dependent on the type of fuel burned.

  16. An assessment and quantitative uncertainty analysis of the health risks to workers exposed to chromium <