Science.gov

Sample records for air contamination level

  1. Air Contamination With Fungals In Museum

    NASA Astrophysics Data System (ADS)

    Scarlat, Iuliana; Haiducu, Maria; Stepa, Raluca

    2015-07-01

    The aim of the studies was to determine the level and kind of fungal contamination of air in museum, deposits patrimony, restoration and conservation laboratories and their effects on health of workers. Microbiological air purity was measured with a SAS-100 Surface Air System impactor. The fungal contamination was observed in all 54 rooms where we made determinations. The highest levels of fungal were recorded at rooms with hygroscopic patrimony objects, eg carpets, chairs, upholstered chairs, books etc. The most species identified included under common allergens: Aspergillus, Penicillium, and Mucor. There fungal species belonging to the genus identified in this study, can trigger serious diseases museum workers, such as for example Aspergillus fumigatus, known allergies and toxic effects that may occur. In some places of the museum, occupational exposure limit values to fungi present in the air in the work environment, recommended by the specialized literature, have been overcome.

  2. Organochlorine pesticides in surface soils from obsolete pesticide dumping ground in Hyderabad City, Pakistan: contamination levels and their potential for air-soil exchange.

    PubMed

    Alamdar, Ambreen; Syed, Jabir Hussain; Malik, Riffat Naseem; Katsoyiannis, Athanasios; Liu, Junwen; Li, Jun; Zhang, Gan; Jones, Kevin C

    2014-02-01

    This study was conducted to examine organochlorine pesticides (OCPs) contamination levels in the surface soil and air samples together with air-soil exchange fluxes at an obsolete pesticide dumping ground and the associated areas from Hyderabad City, Pakistan. Among all the sampling sites, concentrations of OCPs in the soil and air samples were found highest in obsolete pesticide dumping ground, whereas dominant contaminants were dichlorodiphenyltrichloroethane (DDTs) (soil: 77-212,200 ng g(-1); air: 90,700 pg m(-3)) and hexachlorocyclohexane (HCHs) (soil: 43-4,090 ng g(-1); air: 97,400 pg m(-3)) followed by chlordane, heptachlor and hexachlorobenzene (HCB). OCPs diagnostic indicative ratios reflect historical use as well as fresh input in the study area. Moreover, the air and soil fugacity ratios (0.9-1.0) at the dumping ground reflecting a tendency towards net volatilization of OCPs, while at the other sampling sites, the fugacity ratios indicate in some cases deposition and in other cases volatilization. Elevated concentrations of DDTs and HCHs at pesticide dumping ground and its surroundings pose potential exposure risk to biological organisms, to the safety of agricultural products and to the human health. Our study thus emphasizes the need of spatio-temporal monitoring of OCPs at local and regional scale to assess and remediate the future adverse implications.

  3. Elevated CO2 levels affects the concentrations of copper and cadmium in crops grown in soil contaminated with heavy metals under fully open-air field conditions.

    PubMed

    Guo, Hongyan; Zhu, Jianguo; Zhou, Hui; Sun, Yuanyuan; Yin, Ying; Pei, Daping; Ji, Rong; Wu, Jichun; Wang, Xiaorong

    2011-08-15

    Elevated CO(2) levels and the increase in heavy metals in soils through pollution are serious problems worldwide. Whether elevated CO(2) levels will affect plants grown in heavy-metal-polluted soil and thereby influence food quality and safety is not clear. Using a free-air CO(2) enrichment (FACE) system, we investigated the impacts of elevated atmospheric CO(2) on the concentrations of copper (Cu) or cadmium (Cd) in rice and wheat grown in soil with different concentrations of the metals in the soil. In the two-year study, elevated CO(2) levels led to lower Cu concentrations and higher Cd concentrations in shoots and grain of both rice and wheat grown in the respective contaminated soil. Elevated CO(2) levels slightly but significantly lowered the pH of the soil and led to changes in Cu and Cd fractionation in the soil. Our study indicates that elevated CO(2) alters the distribution of contaminant elements in soil and plants, thereby probably affecting food quality and safety.

  4. An accurate derivation of the air dose-rate and the deposition concentration distribution by aerial monitoring in a low level contaminated area

    NASA Astrophysics Data System (ADS)

    Nishizawa, Yukiyasu; Sugita, Takeshi; Sanada, Yukihisa; Torii, Tatsuo

    2015-04-01

    Since 2011, MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan) have been conducting aerial monitoring to investigate the distribution of radioactive cesium dispersed into the atmosphere after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), Tokyo Electric Power Company. Distribution maps of the air dose-rate at 1 m above the ground and the radioactive cesium deposition concentration on the ground are prepared using spectrum obtained by aerial monitoring. The radioactive cesium deposition is derived from its dose rate, which is calculated by excluding the dose rate of the background radiation due to natural radionuclides from the air dose-rate at 1 m above the ground. The first step of the current method of calculating the dose rate due to natural radionuclides is calculate the ratio of the total count rate of areas where no radioactive cesium is detected and the count rate of regions with energy levels of 1,400 keV or higher (BG-Index). Next, calculate the air dose rate of radioactive cesium by multiplying the BG-Index and the integrated count rate of 1,400 keV or higher for the area where the radioactive cesium is distributed. In high dose-rate areas, however, the count rate of the 1,365-keV peak of Cs-134, though small, is included in the integrated count rate of 1,400 keV or higher, which could cause an overestimation of the air dose rate of natural radionuclides. We developed a method for accurately evaluating the distribution maps of natural air dose-rate by excluding the effect of radioactive cesium, even in contaminated areas, and obtained the accurate air dose-rate map attributed the radioactive cesium deposition on the ground. Furthermore, the natural dose-rate distribution throughout Japan has been obtained by this method.

  5. AIRS Level 2 Status

    NASA Technical Reports Server (NTRS)

    Lee, Sung-Yung; Manning, Evan; Olsen, Edward

    2003-01-01

    The Atmospheric Infrared Sounder (AIRS) is a facility instrument onboard EOS Aqua. Major level 2 products are highlighted including temperature profile; water vapor profile; surface skin temperature and other surface parameters; and, cloud friction and top cloud pressure. Level 2 files and data availability are discussed.

  6. Ambient air contamination: Characterization and detection techniques

    NASA Technical Reports Server (NTRS)

    Nulton, C. P.; Silvus, H. S.

    1985-01-01

    Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

  7. Microenvironmental air and soil monitoring of contaminants: An evaluation of indoor and outdoor levels in Chihuahua City

    NASA Astrophysics Data System (ADS)

    Delgado-Rios, Marcos

    Like most of the cities around the world Chihuahua City suffers atmospheric and soil pollution. This is a problem that requires immediate attention from both public authorities and the scientific community. Although it is known that high levels of heavy metals are present in the airborne particulate matter, soil and dust in many urban regions, the information about personal exposure to these pollutants in Chihuahua City is nonexistent. This study focuses on the analysis and characterization of lead and arsenic in the airborne and soil particulate matter present in the interiors of households and their surrounding outdoor environments in the southern part of Chihuahua City. The sampling area chosen for this study was located in the southern part of Chihuahua City. An atmospheric sampling point selected by the Centro de Investigacion en Materiales Avanzados (CIMAV) was selected as a geographical center, with a 2 km radius forming the sampling area. The households selected for analyses were located on Lombardo Toledano Street, a high-traffic street. The main objectives of this study were to establish the maximum exposure level in outdoor and indoor environments for particulate matter less than 10 mum (PM 10), Pb, and As, to determine the background level of Chihuahua City for these same elements, to determine the isotopic ratios of Pb206 and Pb207 in the indoor and outdoor atmospheric samples, and to verify if the source of the pollution is from anthropogenic and/or natural sources. Additionally, a comparison of the analytical data from X-ray fluorescence (XRF) versus the analytical data from inductively coupled plasma with optical emission spectroscopy (ICP-OES) was conducted. The comparison of these techniques was based on sample preparation, speed of analysis, and accuracy of results. In the case of sample preparation, two extraction techniques were performed for a comparison of the extraction/leaching of Pb and As from the samples. These microwave

  8. Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

    NASA Technical Reports Server (NTRS)

    Ramirez, W. Fred; Skliar, Mikhail; Narayan, Anand; Morgenthaler, George W.; Smith, Gerald J.

    1998-01-01

    Control of air contaminants is a crucial factor in the safety considerations of crewed space flight. Indoor air quality needs to be closely monitored during long range missions such as a Mars mission, and also on large complex space structures such as the International Space Station. This work mainly pertains to the detection and simulation of air contaminants in the space station, though much of the work is easily extended to buildings, and issues of ventilation systems. Here we propose a method with which to track the presence of contaminants using an accurate physical model, and also develop a robust procedure that would raise alarms when certain tolerance levels are exceeded. A part of this research concerns the modeling of air flow inside a spacecraft, and the consequent dispersal pattern of contaminants. Our objective is to also monitor the contaminants on-line, so we develop a state estimation procedure that makes use of the measurements from a sensor system and determines an optimal estimate of the contamination in the system as a function of time and space. The real-time optimal estimates in turn are used to detect faults in the system and also offer diagnoses as to their sources. This work is concerned with the monitoring of air contaminants aboard future generation spacecraft and seeks to satisfy NASA's requirements as outlined in their Strategic Plan document (Technology Development Requirements, 1996).

  9. Detection of room air contamination of angiographic CO2 with use of a gas analyzer.

    PubMed

    Culp, William C; Culp, William C

    2002-07-01

    The purpose of this study was to describe a practical method to detect room air contamination in CO2 used for angiography. Samples of CO2 with known room air contamination levels were used in a "bag system" of CO2 delivery and sampled by a gas analyzer commonly used in anesthesia. Nitrogen levels were reliably detected indicating contamination with as little as 2% air. Oxygen levels were reliably detected, indicating contamination with as little as 5% air. Measured CO2 values were unreliable with higher-than-true values at all levels except 100%. All clinically important amounts of N2 and O2 contamination were readily detected by this practical method.

  10. 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...

  11. Fungi as contaminants in indoor air

    NASA Astrophysics Data System (ADS)

    Miller, J. David

    This article reviews the subject of contamination of indoor air with fungal spores. In the last few years there have been advances in several areas of research on this subject. A number of epidemiological studies have been conducted in the U.K., U.S.A. and Canada. These suggest that exposure to dampness and mold in homes is a significant risk factor for a number of respiratory symptoms. Well-known illnesses caused by fungi include allergy and hypersensitivity pneumonitis. There is now evidence that other consequences of exposure to spores of some fungi may be important. In particular, exposure to low molecular weight compounds retained in spores of some molds such as mycotoxins and β 1,3 glucans appears to contribute to some symptoms reported. Fungal contamination of building air is almost always caused by poor design and/or maintenance. Home owners and building operators need to take evidence of fungal contamination seriously.

  12. Air/Superfund national technical guidance study series: Estimation of air impacts for air stripping of contaminated water

    SciTech Connect

    Eklund, B.; Smith, S.; Hunt, M.

    1991-05-01

    Analysis of the air impacts associated with the alternatives to cleaning up Superfund sites is frequently required for planning purposes prior to actual cleanup. Such analyses depend on estimates rather than on field measurements. The report provides procedures for estimating the emissions and ambient air concentrations associated with air stripping - a widely used technique for removing volatile organic compounds (VOC) from contaminated water. Procedures are given to evaluate the effect of the concentration of contaminants in water, the stripping efficiency and the stripping rate on the emission rates and on the ambient air concentrations at selected distances from the air stripper. Henry's Law constants are provided for over 130 compounds to assist in determining stripping efficiencies. Health-based action levels are also provided for the 130 compounds for comparison to the estimated ambient air concentrations. Action levels are also expressed in terms of water concentrations using conservative estimates of emissions and dispersion.

  13. Air cleaning issues with contaminated sites

    SciTech Connect

    Bellamy, R.R.

    1997-08-01

    The US Nuclear Regulatory Commission has developed a list of contaminated sites that warrant special USNRC attention because they pose unique or complex decommissioning issues. This list of radiologically contaminated sites is termed the Site Decommissioning Management Plan (SDMP), and was first issued in 1990. A site is placed on the SDMP list if it has; (1) Problems with the viability of the responsible organization (e.g., the licensee for the site is unable or unwilling to pay for the decommissioning); (2) Large amounts of soil contamination or unused settling ponds or burial grounds that may make the waste difficult to dispose of; (3) The long-term presence of contaminated, unused buildings; (4) A previously terminated license; or (5) Contaminated or potential contamination of the ground water from on-site wastes. In deciding whether to add a site to the SDMP list, the NRC also considers the projected length of time for decommissioning and the willingness of the responsible organization to complete the decommissioning in a timely manner. Since the list was established, 9 sites have been removed from the list, and the current SDMP list contains 47 sites in 11 states. The USNRC annually publishes NUREG-1444, {open_quotes}Site Decommissioning Management Plan{close_quotes}, which updates the status of each site. This paper will discuss the philosophical goals of the SDMP, then will concentrate on the regulatory requirements associated with air cleaning issues at the SDMP sites during characterization and remediation. Both effluent and worker protection issues will be discussed. For effluents, the source terms at sites will be characterized, and measurement techniques will be presented. Off-site dose impacts will be included. For worker protection issues, air sampling analyses will be presented in order to show how the workers are adequately protected and their doses measured to satisfy regulatory criteria during decontamination operations. 1 tab.

  14. Determination of tricresyl phosphate air contamination in aircraft.

    PubMed

    Denola, G; Hanhela, P J; Mazurek, W

    2011-08-01

    Monitoring of tricresyl phosphate (TCP) contamination of cockpit air was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit air contamination suspected to originate from the engine bleed air supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. Air samples were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 air samples were analysed, from 46 different aircraft, and 48 samples were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all samples. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be <5 μg m(-3) compared with the 8-h time-weighted average exposure limit of 100 μg m(-3) for tri-o-cresyl phosphate. The highest concentrations were found at high engine power. Although TCP contamination of cabin/cockpit air has been the subject of much concern in aviation, quantitative data are sparse. PMID:21730359

  15. Determination of tricresyl phosphate air contamination in aircraft.

    PubMed

    Denola, G; Hanhela, P J; Mazurek, W

    2011-08-01

    Monitoring of tricresyl phosphate (TCP) contamination of cockpit air was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit air contamination suspected to originate from the engine bleed air supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. Air samples were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 air samples were analysed, from 46 different aircraft, and 48 samples were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all samples. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be <5 μg m(-3) compared with the 8-h time-weighted average exposure limit of 100 μg m(-3) for tri-o-cresyl phosphate. The highest concentrations were found at high engine power. Although TCP contamination of cabin/cockpit air has been the subject of much concern in aviation, quantitative data are sparse.

  16. Control of indoor air contaminants. Progress report

    SciTech Connect

    Ayer, H.E.

    1988-01-01

    Efforts were made to determine the probability of air contaminants within 1 meter reaching the nose from either a point-source thermal generation of an aerosol or from generations of vapor by evaporation. The study also attempted to define the objective criteria for evaluation of mixing (K) factors between 1 and 10 meters of individual contaminant spaces or in an entire room. Small, thermally generated plumes were able to move with little dilution through spaces of 1 meter and more. Concentrations of acrolein and formaldehyde in side-stream cigarette smoke were tens to hundreds of times the acceptable limits. Between one and two thirds of these concentrations were associated with the particulate phase of the smoke, suggesting that aldehydes may be deposited in the respiratory system rather than absorbed in the nose and trachea, perhaps providing a pathway for bronchial cancer. Concentrations of irritants in contaminant streams sufficient to cause eye or nose/throat irritation may be measured by sampling close enough to the source to trap the entire contaminant stream.

  17. Scrubbing of contaminants from contaminated air streams with aerogel materials with optional photocatalytic destruction

    DOEpatents

    Attia, Yosry A.

    2000-01-01

    Disclosed is a method for separating a vaporous or gaseous contaminant from an air stream contaminated therewith. This method includes the steps of: (a) passing said contaminated air into a contact zone in which is disposed an aerogel material capable of selecting adsorbing said contaminant from air and therein contacting said contaminated air with an aerogel material; and (b) withdrawing from said zone, air depleted of said contaminant. For present purposes, "contaminant" means a material not naturally occurring in ambient air and/or a material naturally occurring in air but present at a concentration above that found in ambient air. Thus, the present invention scrubs (or treats) air for the purpose of returning it to its ambient composition. Also disclosed herein is a process for the photocatalytic destruction of contaminants from an air stream wherein the contaminated air stream is passed into a control cell or contact zone in which is disposed a photocatalytic aerogel and exposing said aerogel to ultraviolet (UV) radiation for photocatalytically destroying the adsorbed contaminant, and withdrawing from said cell an exhaust air stream depleted in said contaminant.

  18. Toxic air contaminants in urban atmospheres: Experience in California

    NASA Astrophysics Data System (ADS)

    Seiber, James N.

    In addition to the criteria gaseous and particulate air pollutants which have been the subject of intensive regulation for many years in the U.S., there exists in the atmosphere of cities and surrounding areas a number of trace toxic contaminants which are of increasing public health and regulatory concern. In California, these Toxic Air Contaminants (TACs) are assessed and regulated by a multi-step process required by legislation. Risk assessment for chemicals which are considered potential TACs involves the gathering and analysis of information on emissions, exposures, toxicology, and epidemiology by two California Agencies, the Air Resources Board and Department of Health Services (now linked by the California Environmental Protection Agency) and an independent Scientific Review Panel. Eighteen chemicals have been designated as TACs since the process started in 1982, including perchloroethylene, formaldehyde, vinyl chloride, and 1,3-butadiene which are mentioned in some detail in this review. Future challenges for risk assessment and management are posed by such issues as gross mixtures, for example, from products of incomplete combustion; transport and deposition out of the originating air basin; contributions of natural sources to ambient levels; and the impact of the list of 189 hazardous air pollutants in the 1990 U.S. Clean Air Act Amendments on California's TAC identification-regulation process. The issues involved in a vigorous pursuit of risk reduction from TACs are discussed based upon experience in California.

  19. Comparison of Air Pollution in Metropolises in China (Beijing) and Japan (Osaka and Nagoya) on the Basis of the Levels of Contaminants and Mutagenicity.

    PubMed

    Coulibaly, Souleymane; Minami, Hiroki; Abe, Maho; Furukawa, Nami; Ono, Ryo; Hasei, Tomohiro; Toriba, Akira; Tang, Ning; Hayakawa, Kazuichi; Funasaka, Kunihiro; Asakawa, Daichi; Ikemori, Fumikazu; Watanabe, Masanari; Honda, Naoko; Wakabayashi, Keiji; Watanabe, Tetsushi

    2016-01-01

    Public concern regarding the transport of air pollutants from mainland East Asia to the leeward area by the prevailing westerlies in spring and winter monsoon has been growing in recent years. We collected total suspended particle (TSP) in Beijing, a metropolis of China located windward of Japan, in spring (late February 2011-May 2011) and in winter (November 2012-early February 2013), then analyzed metals, ions, and organic compounds and mutagenicity, and compared the pollution levels with samples collected at two Japanese metropolises (Osaka and Nagoya) during the same periods. The medians of concentration of TSP and other factors in Beijing were much larger than those in the Japanese metropolises. Especially, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were remarkably high in Beijing in winter, and the median of total PAHs concentration in Beijing was 62-63 times larger than that in the Japanese sites. The mutagenicity of TSP from Beijing toward Salmonella typhimurium YG1024, with and without a mammalian metabolic system (S9 mix), was 13-25 times higher than that from the Japanese sites in winter. These results suggest that air pollution levels in Beijing are very high compared with those at the two Japanese metropolises we evaluated. The diagnostic ratios of PAHs and nitrated polycyclic aromatic hydrocarbons (NPAHs) suggest that the major sources of PAHs and NPAHs in Beijing are different from those at the two Japanese sites in winter, and that the major source in Beijing is coal/biomass combustion.

  20. Circumventing shallow air contamination in Mid Ocean Ridge Basalts

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sujoy; Parai, Rita; Tucker, Jonathan; Middleton, Jennifer; Langmuir, Charles

    2016-04-01

    Noble gases in mantle-derived basalts provide a rich portrait of mantle degassing and surface-interior volatile exchange. However, the ubiquity of shallow-level air contamination frequently obscures the mantle noble gas signal. In a majority of samples, shallow air contamination dominates the noble gas budget. As a result, reconstructing the variability in heavy noble gas mantle source compositions and inferring the history of deep recycling of atmospheric noble gases is difficult. For example, in the gas-rich popping rock 2ΠD43, 129Xe/130Xe ratios reach 7.7±0.23 in individual step-crushes, but the bulk composition of the sample is close to air (129Xe/130Xe of 6.7). Here, we present results from experiments designed to elucidate the source of shallow air contamination in MORBs. Step-crushes were carried out to measure He, Ne, Ar and Xe isotopic compositions on two aliquots of a depleted popping glass that was dredged from between the Kane and Atlantis Fracture Zones of the Mid-Atlantic Ridge in May 2012. One aliquot was sealed in ultrapure N2 after dredge retrieval, while the other aliquot was left exposed to air for 3.5 years. The bulk 20Ne/22Ne and 129Xe/130Xe ratios measured in the aliquot bottled in ultrapure N2 are 12.3 and 7.6, respectively, and are nearly identical to the estimated mantle source values. On the other hand, step crushes in the aliquot left exposed to air for several years show Ne isotopic compositions that are shifted towards air, with a bulk 20Ne/22Ne of 11.5; the bulk 129Xe/130Xe, however, was close to 7.6. These results indicate that lighter noble gases exchange more efficiently between the bubbles trapped in basalt glass and air, suggesting a diffusive or kinetic mechanism for the incorporation of the shallow air contamination. Importantly, in Ne-Ar or Ar-Xe space, step-crushes from the bottled aliquot display a trend that can be easily fit with a simple two-component hyperbolic mixing between mantle and atmosphere noble gases. Step

  1. Indoor air contaminants and their impact on respiratory pathologies.

    PubMed

    Carazo Fernández, Luis; Fernández Alvarez, Ramón; González-Barcala, Francisco Javier; Rodríguez Portal, José Antonio

    2013-01-01

    Humans spend a considerable amount of their time breathing air inside enclosed spaces in which, due to various sources, there may be contaminants that deteriorate the air quality. This is an important risk factor for the health of the general population. This review evaluates the contaminants that are present in the air of indoor air spaces, describing the sources that generate them as well as the physiopathological mechanisms and the diseases that they may cause in the respiratory system. PMID:22704531

  2. Air contamination of a closed anesthesia circuit.

    PubMed

    Mizuno, K; Sumiyoshi, R

    1998-01-01

    Closed-circuit anesthesia (CCA) has certain advantages such as decreased cost, decreased anesthetic gas pollution, improved inhalational gas humidity and temperature in comparison to conventional inhalational anesthesia using a high fresh gas flow, i.e. more than 2 L x min(-1), with a semi-closed breathing circuit. The main disadvantage of CCA is the possibility of hypoxic anesthetic gas delivery. This potentially lethal situation is caused by an insufficient oxygen flow rate for the body metabolism or by the accumulation of inactive gas, usually nitrogen, within the breathing circuit in spite of a sufficient oxygen concentration in the fresh gas supply to the breathing circuit. In the latter case, the accumulation of inactive gas may also lead an increased risk of awareness because of its dilution effect on the concentrations of inhalational anesthetics. We herein present a case of air contamination of the breathing circuit through a sampling line of an anesthetic gas monitor. The air caused a decrease in the oxygen concentration during closed circuit anesthesia.

  3. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum contaminant levels for organic... levels for organic contaminants. (a) The following maximum contaminant levels for organic contaminants... with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c)...

  4. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum contaminant levels for organic... levels for organic contaminants. (a) The following maximum contaminant levels for organic contaminants... with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c)...

  5. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum contaminant levels for organic... levels for organic contaminants. (a) The following maximum contaminant levels for organic contaminants... with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c)...

  6. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum contaminant levels for organic... levels for organic contaminants. (a) The following maximum contaminant levels for organic contaminants... with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c)...

  7. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic... levels for organic contaminants. (a) The following maximum contaminant levels for organic contaminants... with the maximum contaminant level for organic contaminants identified in paragraphs (a) and (c)...

  8. Regenerable Air Purification System for Gas-Phase Contaminant Control

    NASA Technical Reports Server (NTRS)

    Constantinescu, Ileana C.; Finn, John E.; LeVan, M. Douglas; Lung, Bernadette (Technical Monitor)

    2000-01-01

    Tests of a pre-prototype regenerable air purification system (RAPS) that uses water vapor to displace adsorbed contaminants from an adsorbent column have been performed at NASA Ames Research Center. A unit based on this design can be used for removing trace gas-phase contaminants from spacecraft cabin air or from polluted process streams including incinerator exhaust. During the normal operation mode, contaminants are removed from the air on the column. Regeneration of the column is performed on-line. During regeneration, contaminants are displaced and destroyed inside the closed oxidation loop. In this presentation we discuss initial experimental results for the performance of RAPS in the removal and treatment of several important spacecraft contaminant species from air.

  9. Use of blood levels to infer carcass levels of contaminants

    USGS Publications Warehouse

    Hensler, G.L.; Stout, William C.

    1982-01-01

    Inferences may be made about the carcass levels of a contaminant based on the contaminant level in blood samples. A method is given for comparing such populations that utilizes bivariate normal distributions and their principal axes, thereby avoiding a dilemma arising from the use of regression techniques. Confidence intervals and power calculations are given. Data from captive barn owls provide partial justification for the use of this method.

  10. Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

    NASA Technical Reports Server (NTRS)

    Ramirez, W. Fred; Skliar, Mikhail; Narayan, Anand; Morgenthaler, George W.; Smith, Gerald J.

    1996-01-01

    Progress and results in the development of an integrated air quality modeling, monitoring, fault detection, and isolation system are presented. The focus was on development of distributed models of the air contaminants transport, the study of air quality monitoring techniques based on the model of transport process and on-line contaminant concentration measurements, and sensor placement. Different approaches to the modeling of spacecraft air contamination are discussed, and a three-dimensional distributed parameter air contaminant dispersion model applicable to both laminar and turbulent transport is proposed. A two-dimensional approximation of a full scale transport model is also proposed based on the spatial averaging of the three dimensional model over the least important space coordinate. A computer implementation of the transport model is considered and a detailed development of two- and three-dimensional models illustrated by contaminant transport simulation results is presented. The use of a well established Kalman filtering approach is suggested as a method for generating on-line contaminant concentration estimates based on both real time measurements and the model of contaminant transport process. It is shown that high computational requirements of the traditional Kalman filter can render difficult its real-time implementation for high-dimensional transport model and a novel implicit Kalman filtering algorithm is proposed which is shown to lead to an order of magnitude faster computer implementation in the case of air quality monitoring.

  11. Fuzzy measurement based image testing for oil particles contamination level

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Zhang, Xianming; Li, Chuan; Chen, Bin

    2010-11-01

    The oil contamination level testing is important for its using and maintenance which is the basement of the oil contamination control is required higher by the developing device system, and the testing method is urgently needed to be studied for improving the process method and the maintenance quality of the contaminated oil. To classify the level of particles contamination in lubricant, CCD imaging technology is used to capture microscopic digital image of the oil particles sample . The digital image was processed and segmented in order that the computer can recognize and understand the particle targets by using image testing algorithm to measure the sizes, amounts and distributions of particles. The oil contamination level can be measured effectively by the economical and convenient method in which there is little air bubble and bead leading to false particle targets. To improve the influence produced by the false particle targets, One method is that a series of dynamical image samples from the contaminated oil in the multi-period and the multi-state are captured and used to test the particle targets, and the further method is to employ the fuzzy measurement using Gaussian subjection function, which describes the distribution of the standard evidences and the distribution of the testing data, and the testing probabilities of the evidence are weighed by the matching degree of the two distributions, which is used to classify the oil particles contamination level .The test shows that the oil particles contamination level diagnosis reliability is improved and the diagnosis uncertainty is reduced. This method combining with other testing methods by using the multi-information fusion method will be further studied later.

  12. A source of PCB contamination in modified high-volume air samplers

    SciTech Connect

    Basu, I.; O'Dell, J.M.; Arnold, K.; Hites, R.A.

    2000-02-01

    Modified Anderson High Volume (Hi-Vol) air samplers are widely used for the collection of semi-volatile organic compounds (such as PCBs) from air. The foam gasket near the main air flow path in these samplers can become contaminated with PCBs if the sampler or the gasket is stored at a location with high indoor air PCB levels. Once the gasket is contaminated, it releases PCBs back into the air stream during sampling, and as a result, incorrectly high air PCB concentrations are measured. This paper presents data demonstrating this contamination problem using measurements from two Integrated Atmospheric Deposition Network sites: one at Sleeping Bear Dunes on Lake Michigan and the other at Point Petre on Lake Ontario. The authors recommend that these gaskets be replaced by Teflon tape and that the storage history of each sampler be carefully tracked.

  13. Particulate Air Contamination in Puerto Rico: A Student Involvement Project.

    ERIC Educational Resources Information Center

    Eckert, Richard R.

    1979-01-01

    Describes a research project undertaken by physics undergraduate students to monitor particulate air contamination in Ponce, Puerto Rico, and to determine the meteorological factors which contribute to it. (GA)

  14. ESTIMATION OF BACKGROUND LEVELS OF CONTAMINANTS

    EPA Science Inventory

    Samples from hazardous waste site investigations frequently come from two or more statistical populations. Assessment of "background" levels of contaminants can be a significant problem. This problem is being investigated at the US EPA's EMSL in Las Vegas. This paper describes a ...

  15. Treatment of contaminated groundwaters with granular activated carbon and air stripping

    SciTech Connect

    Stenzel, M.H.; Gupta, U.S.

    1985-01-01

    Over the past several years there have been increasing reports of cases of contaminated groundwater. Many cases were caused by leaking from surface impoundments or landfills, or leakage from underground storage tanks. Treatment of groundwater use, discharge or recharge into the aquifer is becoming a major concern. Two widely used treatment techniques are adsorption with granular activated carbon and packed tower air stripping. Granular activated carbon is often applied when organic contaminants need to be removed to nondetectable levels, and should be a part of the process if nonvolatile contaminants are present. Air stripping is capable of 95-99% reduction of volatile contaminants and can be a cost effective treatment technology if nondetectable contaminant levels are not required and air pollution is not a factor. Should off-gas from an air stripper require treatment for removal of organic contaminants, granular activated carbon adsorption can be effectively applied as it was in the water phase. Selection of a groundwater treatment technology depends on factors such as contaminant type, end use of the water and air pollution concern, and each case requires consideration of these factors to arrive at the most cost effective solution.

  16. Air side contamination in Solid Oxide Fuel Cell stack testing

    NASA Astrophysics Data System (ADS)

    Schuler, J. Andreas; Gehrig, Christian; Wuillemin, Zacharie; Schuler, Albert J.; Wochele, Joerg; Ludwig, Christian; Hessler-Wyser, Aïcha; Van herle, Jan

    This work aimed to quantify air side contaminants during Solid Oxide Fuel Cell (SOFC) testing in stack configuration. Post-analyses of a long-term test have shown that performance degradation was mainly due to cathode pollutants originated upstream of the cell, therefore their source identification is crucial. The compressed air system, feeding the airflow to the cathode, was investigated by filtering and subsequent chemical analysis of the filters. Hot-air-sampling was redone in situ at the cathode air entry during a new test run to assess the contaminant concentrations in air in SOFC test conditions. In addition, the behavior of SOFC proximal system components, i.e. alloy oxidation, was characterized separately. Besides the investigation of silicon and sulfur contamination, the present work focused on chromium from high-temperature alloys used in Balance-of-Plant (BoP) components in direct contact with the airflow. Concentrations of volatile Cr-species under SOFC testing conditions were compared to Cr-accumulation on the tested cell as well as to Cr-evaporation rates from BoP alloys, which were individually characterized regarding oxidation behavior. Evaporated Cr quantities were found to saturate the air with Cr-vapors at the cathode air-inlet, as confirmed by the in-situ measurement of volatile species in the hot airflow, and correlate well to accumulated Cr in the cell after long term testing. The results of this study suggest guidelines to reduce air side contamination from exogenous sources in SOFC stacks.

  17. Wash-out of ambient air contaminations for breath measurements.

    PubMed

    Maurer, F; Wolf, A; Fink, T; Rittershofer, B; Heim, N; Volk, T; Baumbach, J I; Kreuer, S

    2014-06-01

    In breath analysis, ambient air contaminations are ubiquitous and difficult to eliminate. This study was designed to investigate the reduction of ambient air background by a lung wash-out with synthetic air. The reduction of the initial ambient air volatile organic compound (VOC) intensity was investigated in the breath of 20 volunteers inhaling synthetic air via a sealed full face mask in comparison to inhaling ambient air. Over a period of 30 minutes, breath analysis was conducted using ion mobility spectrometry coupled to a multi-capillary column. A total of 68 VOCs were identified for inhaling ambient air or inhaling synthetic air. By treatment with synthetic air, 39 VOCs decreased in intensity, whereas 29 increased in comparison to inhaling ambient air. In total, seven VOCs were significantly reduced (P-value < 0.05). A complete wash-out of VOCs in this setting was not observed, whereby a statistically significant reduction up to 65% as for terpinolene was achieved. Our setting successfully demonstrated a reduction of ambient air contaminations from the airways by a lung wash-out with synthetic air.

  18. 29 CFR 1910.1000 - Air contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... in subpart Z of 29 CFR part 1910 in order to determine whether an employee is exposed over the... weighted average specified in subpart Z of 29 CFR part 1910 for the substance involved. (ii) To illustrate... contaminant. L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1910. The...

  19. 29 CFR 1910.1000 - Air contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in subpart Z of 29 CFR part 1910 in order to determine whether an employee is exposed over the... weighted average specified in subpart Z of 29 CFR part 1910 for the substance involved. (ii) To illustrate... contaminant. L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1910. The...

  20. 29 CFR 1910.1000 - Air contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... in subpart Z of 29 CFR part 1910 in order to determine whether an employee is exposed over the... weighted average specified in subpart Z of 29 CFR part 1910 for the substance involved. (ii) To illustrate... contaminant. L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1910. The...

  1. 29 CFR 1910.1000 - Air contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... in subpart Z of 29 CFR part 1910 in order to determine whether an employee is exposed over the... weighted average specified in subpart Z of 29 CFR part 1910 for the substance involved. (ii) To illustrate... contaminant. L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1910. The...

  2. 29 CFR 1915.1000 - Air contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... subpart Z of 29 CFR part 1915 in order to determine whether an employee is exposed over the regulatory... average specified in subpart Z of 29 CFR part 1915 for the material involved. (ii) To illustrate the... particular contaminant. L is the exposure limit for that substance specified in subpart Z of 29 CFR part...

  3. [Study on the groundwater petroleum contaminant remediation by air sparging].

    PubMed

    Wang, Zhi-Qiang; Wu, Qiang; Zou, Zu-Guang; Chen, Hong; Yang, Xun-Chang; Zhao, Ji-Chu

    2007-04-01

    The groundwater petroleum contaminant remediation effect by air sparging was investigated in an oil field. The results show that the soil geological situation has great influence on the air distribution, and the shape of air distribution is not symmetrical to the air sparging (AS) well as axis. The influence distance in the left of AS well is 6 m, and only 4 m in the right. The petroleum removal rate can reach 70% in the zone with higher air saturation, but only 40% in the zone with lower air saturation, and the average petroleum removal rate reaches 60% in the influence zone for 40 days continuous air sparging. The petroleum components in groundwater were analyzed by GC/MS (gas chromatogram-mass spectrograph) before and after experiments, respectively. The results show that the petroleum removal rate has relationship with the components and their properties. The petroleum components with higher volatility are easily removed by volatilization, but those with lower volatility are difficult to remove, so a tailing effect of lingering residual contaminant exists when the air sparging technology is adopted to treat groundwater contaminated by petroleum products.

  4. Achieving indoor air quality through contaminant control

    SciTech Connect

    Katzel, J.

    1995-07-10

    Federal laws outlining industry`s responsibilities in creating a healthy, hazard-free workspace are well known. OSHA`s laws on interior air pollution establish threshold limit values (TLVs) and permissible exposure limits (PELs) for more than 500 potentially hazardous substances found in manufacturing operations. Until now, OSHA has promulgated regulations only for the manufacturing environment. However, its recently-proposed indoor air quality (IAQ) ruling, if implemented, will apply to all workspaces. It regulates IAQ, including environmental tobacco smoke, and requires employers to write and implement IAQ compliance plans.

  5. AIRS Level 2 Data Products

    NASA Technical Reports Server (NTRS)

    Vicente, Gilberto

    2003-01-01

    The Atmospheric InfraRed Sounder (AIRS) Standard Retrieval Product consists of retrieved cloud and surface properties; profiles of retrieved temperature, water vapor, and ozone; and a flag indicating the presence of cloud ice or water. They contain quality assessment flags in addition to retrieved quantities and are generated for all locations where atmospheric soundings are taken. An AIRS granule consists of 6 minutes of data. This corresponds to approximately 1/15 of an orbit but exactly 45 scan lines of AMSU-A data or 135 scan lines of AIRS and HSB data.

  6. Air emissions from exposed contaminated sediments and dredged material

    SciTech Connect

    Valsaraj, K.T.; Ravikrishna, R.; Reible, D.D.; Thibodeaux, L.J.; Choy, B.; Price, C.B.; Brannon, J.M.; Myers, T.E.; Yost, S.

    1999-01-01

    The sediment-to-air fluxes of two polycyclic aromatic hydrocarbons (phenanthrene and pyrene) and a heterocyclic aromatic hydrocarbon (dibenzofuran) from a laboratory-contaminated sediment and those of three polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, and pyrene) from three field sediments were investigated in experimental microcosms. The flux was dependent on the sediment moisture content, air-filled porosity, and the relative humidity of the air flowing over the sediment surface. The mathematical model predictions of flux from the laboratory-spiked sediment agreed with observed values. The fluxes of compounds with higher hydrophobicity were more air-side resistance controlled. Conspicuous differences were observed between the fluxes from the laboratory-spiked and two of the three field sediments. Two field sediments showed dramatic increases in mass-transfer resistances with increasing exposure time and had significant fractions of oil and grease. The proposed mathematical model was inadequate for predicting the flux from the latter field sediments. Sediment reworking enhanced the fluxes from the field sediments due to exposure of fresh solids to the air. Variations in flux from the lab-spiked sediment as a result of change in air relative humidity were due to differences in retardation of chemicals on a dry or wet surface sediment. High moisture in the air over the dry sediment increased the competition for sorption sites between water and contaminant and increased the contaminant flux.

  7. Effect of air-conditioner on fungal contamination

    NASA Astrophysics Data System (ADS)

    Hamada, Nobuo; Fujita, Tadao

    Air-conditioners (AC) produce much dew and wet conditions inside their apparatus, when in operation. We studied the fungal contamination in AC and found that the average fungal contamination of AC filters was about 5-fold greater than that of a carpet, and Cladosporium and Penicillium were predominant in AC filters. The fungal contamination inside AC, which were used everyday, increased more markedly than those not used daily, e.g. a few days per week or rarely. Moreover, the airborne fungal contamination in rooms during air-conditioning was about 2-fold greater than one in rooms without AC, and was highest when air-conditioning started and decreased gradually with time. We recognized that the airborne fungal contamination was controlled by the environmental condition of the rooms, in which AC were used. It is suggested that AC might promote mold allergies in users via airborne fungal spores derived from the AC. On the other hand, AC was estimated to remove moisture in the room atmosphere and carpets, and reduce the relative humidity in rooms. It was found that the average fungal contamination in the house dust of carpets with AC was suppressed by two-third of that in rooms without AC. The use of AC for suppressing fungal hazards was discussed.

  8. Spacecraft contamination programs within the Air Force Systems Command Laboratories

    NASA Technical Reports Server (NTRS)

    Murad, Edmond

    1990-01-01

    Spacecraft contamination programs exist in five independent AFSC organizations: Geophysics Laboratory (GL), Arnold Engineering and Development Center (AEDC), Rome Air Development Center (RADC/OSCE), Wright Research and Development Center (MLBT), Armament Laboratory (ATL/SAI), and Space Systems Division (SSD/OL-AW). In addition, a sizable program exists at Aerospace Corp. These programs are complementary, each effort addressing a specific area of expertise: GL's effort is aimed at addressing the effects of on-orbit contamination; AEDC's effort is aimed at ground simulation and measurement of optical contamination; RADC's effort addresses the accumulation, measurement, and removal of contamination on large optics; MLBT's effort is aimed at understanding the effect of contamination on materials; ATL's effort is aimed at understanding the effect of plume contamination on systems; SSD's effort is confined to the integration of some contamination experiments sponsored by SSD/CLT; and Aerospace Corp.'s effort is aimed at supporting the needs of the using System Program Offices (SPO) in specific areas, such as contamination during ground handling, ascent phase, laboratory measurements aimed at understanding on-orbit contamination, and mass loss and mass gain in on-orbit operations. These programs are described in some detail, with emphasis on GL's program.

  9. Carbon monoxide and water vapor contamination of compressed breathing air for firefighters and divers.

    PubMed

    Austin, C C; Ecobichon, D J; Dussault, G; Tirado, C

    1997-12-12

    Compressed breathing air, used in self-contained breathing apparatus (SCBA) by firefighters and other categories of workers as well as by recreational and commercial divers, is prepared with the aid of high-pressure compressors operating in the range of 5000 psig. There have been reports of unexplained deaths of SCUBA divers and anecdotal accounts of decreased time to exhaustion in firefighters using SCBAs. Compressed breathing air has been found to contain elevated levels of carbon monoxide (CO) and water vapor that are consistent with carboxyhemoglobin (COHb) poisoning and freezing of the user's regulator on the breathing apparatus. The Coburn-Forster-Kane equation (CFK equation) was used to estimate COHb levels at rest and at maximum exercise when exposed to different levels of CO in contaminated breathing air. The results demonstrated that, at maximum exercise, the COHb ranged from 6.0 to 17% with the use of 1 to 4 SCBA cylinders contaminated by 250 ppm CO. Standard operating procedures have been developed at the Montreal Fire Department to minimize the risk of compressed breathing air contamination. Results of the quality analysis/quality control program indicate that implementation of these procedures has improved the quality of the compressed breathing air. Recommendations are made for improvement of the air testing procedures mandated by the Canadian CAN3 180.1-M85 Standard on Compressed Breathing Air and Systems.

  10. Occupational exposure to laser surgery generated air contaminants.

    PubMed

    Blustein, D; Blustein, J

    1998-04-01

    The objective of the review is to show that scientific evidence is lacking on the safety of laser-generated air contaminants. Further research and data collection are necessary to characterize the potential dangers associated with exposures of health care professionals to laser generated air contaminants. The article is a review of existing scientific evidence in the area of exposure risks to health care professionals. A careful search of the scientific literature both in medicine and engineering was performed, as well as contact with experts from laser standards advisory sources. These sources include: International Laser Safety Conference, National Institute of Occupational Safety and Health, American National Standard Institute, Laser Safety Institute and Rockwell Laser Industries. The review includes articles in the literature documenting cases of over-exposures to contaminants while using a class IV laser, the same class laser used in surgery. Several studies of case reports of laser-generated air contaminants from cutting on human and animal tissues are included. Articles and guidelines on this subject of laser-generated contaminants from the above listed sources were used in writing this review. The review indicates that lasers used in surgery are potential occupational health risks.

  11. 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...

  12. THE ALLERGENIC POTENTIAL OF INDOOR AIR FUNGAL CONTAMINANTS

    EPA Science Inventory


    The Allergenic Potential of Indoor Air Fungal Contaminants
    Marsha D W Ward1, Michael E Viana2, Yongjoo 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, SPH,...

  13. RADIAL COMPUTED TOMOGRAPHY OF AIR CONTAMINANTS USING OPTICAL REMOTE SENSING

    EPA Science Inventory

    The paper describes the application of an optical remote-sensing (ORS) system to map air contaminants and locate fugitive emissions. Many ORD systems may utilize radial non-overlapping beam geometry and a computed tomography (CT) algorithm to map the concentrations in a plane. In...

  14. Air contaminant control investigation of a jet augmented local exhaust system

    SciTech Connect

    Cameron, D.B.; Johnston, W.L.; Konzen, R.B.

    1987-01-01

    The feasibility of a jet augmented local exhaust system to control air contaminants was investigated in a scale model hood. Tracer gas concentrations were mapped on top of idealized airflow streamlines to illustrate the jet's interaction with air contaminants. A key findings was the possibility of contaminant loss from the hood if the jet flow was not recaptured completely. Airflow design parameters, which had been identified previously to affect the airflow pattern, were evaluation for their effect on air contaminant control. The results indicated that tracer gas recovery was affected by a single airflow design parameters. An inverse linear relationship between the design parameter and control levels indicated that the recovery rate was controllable in design and that 100% control was achievable at a low total airflow rate. Important potential design advantages include the ability to specify the contaminant control level prior to installation, system flexibility to change contaminant control levels by adjusting airflow design parameters, and lower installation and operation costs than a comparable local exhaust system. The next research step is to test a full-scale prototype system to evaluate its performance efficiency and economy under realistic operating conditions.

  15. An investigation of the source of air Ar contamination in KAr dating

    USGS Publications Warehouse

    Mussett, A.E.; Brent, Dalrymple G.

    1968-01-01

    Precision of young KAr ages is limited by air argon contamination. A series of experiments in which the exposure of basalt and sanidine samples to air argon was controlled, shows that most of the air contamination does not arise in the laboratory. Because of this, it seems unlikely that air argon contamination can be significantly reduced by special sample handling and preparation techniques. ?? 1968.

  16. Air stripping of contaminated water sources - air emissions and controls. Final report

    SciTech Connect

    Vancit, M.A.; Howle, R.H.; Herndon, D.J.; Shareef, S.A.

    1987-08-01

    Air-stripping towers are being used to remove low concentrations of organic contaminants from water. The report describes the technology and methods used to control air pollution resulting from this procedure. The cost of the controls is presented along with other positive and negative impacts of the technology.

  17. Exposure of firefighters to toxic air contaminants.

    PubMed

    Gold, A; Burgess, W A; Clougherty, E V

    1978-07-01

    A personal sampling apparatus for firefighters was developed to sample the fire atmosphere for CO, CO2, O2, NO2, HCI, HCN and pariculate content. Two fire companies made ninety successful sample runs during structural fires. CO presented a potential acute hazard and particulate concentrations were high. HCN was detected at low levels in half the samples. HCI was detected in only eight samples but on two occasions exceeded 100 ppm. CO2 and NO2 levels and O2 depression do not appear to represent significant hazards. PMID:211840

  18. Open air demolition of facilities highly contaminated with plutonium

    SciTech Connect

    Lloyd, E.R.; Lackey, M.B.; Stevens, J.M.; Zinsli, L.C.

    2007-07-01

    The demolition of highly contaminated plutonium buildings usually is a long and expensive process that involves decontaminating the building to near free- release standards and then using conventional methods to remove the structure. It doesn't, however, have to be that way. Fluor has torn down buildings highly contaminated with plutonium without excessive decontamination. By removing the select source term and fixing the remaining contamination on the walls, ceilings, floors, and equipment surfaces; open-air demolition is not only feasible, but it can be done cheaper, better (safer), and faster. Open-air demolition techniques were used to demolish two highly contaminated buildings to slab-on-grade. These facilities on the Department of Energy's Hanford Site were located in, or very near, compounds of operating nuclear facilities that housed hundreds of people working on a daily basis. To keep the facilities operating and the personnel safe, the projects had to be creative in demolishing the structures. Several key techniques were used to control contamination and keep it within the confines of the demolition area: spraying fixatives before demolition; applying fixative and misting with a fine spray of water as the buildings were being taken down; and demolishing the buildings in a controlled and methodical manner. In addition, detailed air-dispersion modeling was done to establish necessary building and meteorological conditions and to confirm the adequacy of the proposed methods. Both demolition projects were accomplished without any spread of contamination outside the modest buffer areas established for contamination control. Furthermore, personnel exposure to radiological and physical hazards was significantly reduced by using heavy equipment rather than 'hands on' techniques. (authors)

  19. OPEN AIR DEMOLITION OF FACILITIES HIGHLY CONTAMINATED WITH PLUTONIUM

    SciTech Connect

    LLOYD, E.R.

    2007-05-31

    The demolition of highly contaminated plutonium buildings usually is a long and expensive process that involves decontaminating the building to near free- release standards and then using conventional methods to remove the structure. It doesn't, however, have to be that way. Fluor has torn down buildings highly contaminated with plutonium without excessive decontamination. By removing the select source term and fixing the remaining contamination on the walls, ceilings, floors, and equipment surfaces; open-air demolition is not only feasible, but it can be done cheaper, better (safer), and faster. Open-air demolition techniques were used to demolish two highly contaminated buildings to slab-on-grade. These facilities on the Department of Energy's Hanford Site were located in, or very near, compounds of operating nuclear facilities that housed hundreds of people working on a daily basis. To keep the facilities operating and the personnel safe, the projects had to be creative in demolishing the structures. Several key techniques were used to control contamination and keep it within the confines of the demolition area: spraying fixatives before demolition; applying fixative and misting with a fine spray of water as the buildings were being taken down; and demolishing the buildings in a controlled and methodical manner. In addition, detailed air-dispersion modeling was done to establish necessary building and meteorological conditions and to confirm the adequacy of the proposed methods. Both demolition projects were accomplished without any spread of contamination outside the modest buffer areas established for contamination control. Furthermore, personnel exposure to radiological and physical hazards was significantly reduced by using heavy equipment rather than ''hands on'' techniques.

  20. Analytical model for contaminant mass removal by air sparging

    SciTech Connect

    Rabideau, A.J.; Blayden, J.M.

    1998-12-31

    An analytical model was developed to predict the removal of volatile organic compounds (VOCs) from ground water by air sparging (AS). The model treats the air sparging zone as a completely mixed reactor subject to the removal of dissolved contaminants by volatilization, advection, and first-order decay. Nonequilibrium desorption is approximated as a first-order mass transfer process. The model reproduces the tailing and rebound behavior often observed at AS sites, and would normally require the estimation of three site-specific parameters. Dimensional analysis demonstrates that predicting tailing can be interpreted in terms of kinetic desorption or diffusion of aqueous phase contaminants into discrete air channels. Related work is ongoing to test the model against field data.

  1. Processing AIRS Scientific Data Through Level 3

    NASA Technical Reports Server (NTRS)

    Granger, Stephanie; Oliphant, Robert; Manning, Evan

    2010-01-01

    The Atmospheric Infra-Red Sounder (AIRS) Science Processing System (SPS) is a collection of computer programs, known as product generation executives (PGEs). The AIRS SPS PGEs are used for processing measurements received from the AIRS suite of infrared and microwave instruments orbiting the Earth onboard NASA's Aqua spacecraft. Early stages of the AIRS SPS development were described in a prior NASA Tech Briefs article: Initial Processing of Infrared Spectral Data (NPO-35243), Vol. 28, No. 11 (November 2004), page 39. In summary: Starting from Level 0 (representing raw AIRS data), the AIRS SPS PGEs and the data products they produce are identified by alphanumeric labels (1A, 1B, 2, and 3) representing successive stages or levels of processing. The previous NASA Tech Briefs article described processing through Level 2, the output of which comprises geo-located atmospheric data products such as temperature and humidity profiles among others. The AIRS Level 3 PGE samples selected information from the Level 2 standard products to produce a single global gridded product. One Level 3 product is generated for each day s collection of Level 2 data. In addition, daily Level 3 products are aggregated into two multiday products: an eight-day (half the orbital repeat cycle) product and monthly (calendar month) product.

  2. A Stochastic Model for Infective Events in Operating Room Caused by Air Contamination

    NASA Astrophysics Data System (ADS)

    Abundo, Paolo; Rosato, Nicola; Abundo, Mario

    2008-07-01

    We propose a simple stochastic model for the movement of a potentially infective particle in operating room in which the local air contamination level is reduced by using a double laminar flow. Numerical simulation is used to obtain qualitative scenario analysis, in order to prevent infection, i.e. impact of the infective particle with the surgical wound, during the operation.

  3. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.52 Maximum contaminant level goals...

  4. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.52 Maximum contaminant level goals...

  5. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.52 Maximum contaminant level goals...

  6. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.52 Maximum contaminant level goals...

  7. 40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum contaminant level goals for microbiological contaminants. 141.52 Section 141.52 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.52 Maximum contaminant level goals...

  8. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.50 Maximum contaminant level goals for...

  9. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.50 Maximum contaminant level goals for...

  10. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.50 Maximum contaminant level goals for...

  11. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.50 Maximum contaminant level goals for...

  12. 40 CFR 141.50 - Maximum contaminant level goals for organic contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum contaminant level goals for organic contaminants. 141.50 Section 141.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.50 Maximum contaminant level goals for...

  13. Quantitative assessment of bio-aerosols contamination in indoor air of University dormitory rooms

    PubMed Central

    Hayleeyesus, Samuel Fekadu; Ejeso, Amanuel; Derseh, Fikirte Aklilu

    2015-01-01

    Objectives The purpose of this study is to provide insight into how students are exposed to indoor bio-aerosols in the dormitory rooms and to figure out the major possible factors that govern the contamination levels. Methodology The Bio-aerosols concentration level of indoor air of thirty dormitory rooms of Jimma University was determined by taking 120 samples. Passive air sampling technique; the settle plate method using open Petri-dishes containing different culture media was employed to collect sample twice daily. Results The range of bio-aerosols contamination detected in the dormitory rooms was 511–9960 CFU/m3 for bacterial and 531–6568 CFU/m3 for fungi. Based on the criteria stated by WHO expert group, from the total 120 samples 95 of the samples were above the recommended level. The statistical analysis showed that, occupancy were significantly affected the concentrations of bacteria that were measured in all dormitory rooms at 6:00 am sampling time (p-value=0.000) and also the concentrations of bacteria that were measured in all dormitory rooms were significantly different to each other (p-value=0.013) as of their significance difference in occupancy (p-value=0.000). Moreover, there were a significant different on the contamination level of bacteria at 6:00 am and 7:00 pm sampling time (p=0.015), whereas there is no significant difference for fungi contamination level for two sampling times (p= 0.674). Conclusion There is excessive bio-aerosols contaminant in indoor air of dormitory rooms of Jimma University and human occupancy produces a marked concentration increase of bacterial contamination levels and most fungi species present into the rooms air of Jimma University dormitory were not human-borne. PMID:26609289

  14. Concentrations of selected contaminants in cabin air of airbus aircrafts.

    PubMed

    Dechow, M; Sohn, H; Steinhanses, J

    1997-07-01

    The concentrations of selected air quality parameters in aircraft cabins were investigated including particle numbers in cabin air compared to fresh air and recirculation air, the microbiological contamination and the concentration of volatile organic compounds (VOC). The Airbus types A310 of Swissair and A340 of Lufthansa were used for measurements. The particles were found to be mainly emitted by the passengers, especially by smokers. Depending on recirculation filter efficiency the recirculation air contained a lower or equal amount of particles compared to the fresh air, whereas the amount of bacteria exceeded reported concentrations within other indoor spaces. The detected species were mainly non-pathogenic, with droplet infection over short distances identified as the only health risk. The concentration of volatile organic compounds (VOC) were well below threshold values. Ethanol was identified as the compound with the highest amount in cabin air. Further organics were emitted by the passengers--as metabolic products or by smoking--and on ground as engine exhaust (bad airport air quality). Cleaning agents may be the source of further compounds.

  15. Regenerable Air Purification System for Gas-Phase Contaminant Control

    NASA Technical Reports Server (NTRS)

    Constantinescu, Ileana C.; Qi, Nan; LeVan, M. Douglas; Finn, Cory K.; Finn, John E.; Luna, Bernadette (Technical Monitor)

    2000-01-01

    A regenerable air purification system (RAPS) that uses water vapor to displace adsorbed contaminants from an. adsorbent column into a closed oxidation loop is under development through cooperative R&D between Vanderbilt University and NASA Ames Research Center. A unit based on this design can be used for removing trace gas-phase contaminants from spacecraft cabin air or from polluted process streams including incinerator exhaust. Recent work has focused on fabrication and operation of a RAPS breadboard at NASA Ames, and on measurement of adsorption isotherm data for several important organic compounds at Vanderbilt. These activities support the use and validation of RAPS modeling software also under development at Vanderbilt, which will in turn be used to construct a prototype system later in the project.

  16. Microbial air contamination in indoor environment of a university library.

    PubMed

    Kalwasińska, Agnieszka; Burkowska, Aleksandra; Wilk, Iwona

    2012-01-01

    The present study was aimed at evaluating the number of bacteria and mould fungi in the indoor and outdoor environment of Toruń University Library. The sampling sites were located in the rooms serving the functions typical of libraries (i.e. in the Main Reading Room, Current Periodicals Reading Room, Collections Conservation Laboratory, Old Prints Storeroom, in rooms serving other (non-library) functions (i.e. main hall, cafeteria, and toilet) as well as outside the library building. The analyses reveal that the concentrations of bacterial as well as fungal aerosols estimated with the use of the impaction method ranged between 10(1)-10(3) CFU·m(-3), which corresponds to the concentrations normally observed in areas of this kind. Evaluation of the hygienic condition of the studied areas was based on the criteria for microbiological cleanliness in interiors submitted by the European Commission in 1993. According to this classification, the air was considered to be heavily or moderately contaminated with bacteria, while the air contamination with mould fungi was described as low or moderate. The air in the Old Prints Storeroom was considered the least contaminated with microbial aerosol.

  17. Control of gas contaminants in air streams through biofiltration

    SciTech Connect

    Holt, T.; Lackey, L.

    1996-11-01

    According to the National Institute for Occupational Safety and Health (NIOSH), the maximum styrene concentration allowed in the work place is 50 ppm for up to a 10-hour work day during a 40-hour work week. The US EPA has classified styrene as one of the 189 hazardous air pollutants listed under Title 3 of the Clean Air Act Amendments to be reduced by a factor of 90% by the year 2000. Significant quantities of styrene are emitted to the atmosphere each year by boat manufacturers. A typical fiberglass boat manufacturing facility can emit over 273 metric tons/year of styrene. The concentration of styrene in the industrial exhaust gas ranges from 20 to 100 ppmv. Such dilute, high volume organically tainted air streams can make conventional abatement technologies such as thermal incineration, adsorption, or absorption technically incompetent or prohibitively expensive. An efficient, innovative, and economical means of remediating styrene vapors would be of value to industries and to the environment. Biofilter technology depends on microorganisms that are immobilized on the packing material in a solid phase reactor to remove or degrade environmentally undesirable compounds contaminating gas streams. The technology is especially successful for treating large volumes of air containing low concentrations of contaminants. The objective of this study was to investigate the feasibility of using biofiltration to treat waste gas streams containing styrene and to determine the critical design and operating parameters for such a system.

  18. Ventilating-air change rate versus particulate contaminant spread

    SciTech Connect

    Langer, G.; Deitesfeld, C.A.

    1987-11-13

    This study provides information on the spread of particulate contamination from glovebox leaks in plutonium manufacturing facilities, with emphasis on the effect of ventilating-air change rate on contaminated spread. A new, very sensitive aerosol tracer technique was developed to simulate plutonium aerosol leaks and its dispersion in a room. The tracer, a submicron aerosol of phloroglucinol, does not interfere with work activity and is detected by its ability to form ice crystals in a supercooled cloud. This technique was applied in Buildings 371 and 707 plutonium production areas. The tracer spread throughout the rooms in a few minutes and reached its equilibrium concentration in 10 to 25 min. Also, to clear the room of all tracer took about the same time. In one room, tracer concentration decreased proportionally to the air change rate, while in the second one, air change rate had no effect. This points out the need for air velocity data. Also, future work must include simultaneous particle concentration measurements at several points. 4 refs., 9 figs., 2 tabs.

  19. Exposure to varying levels of contaminants and symptoms among workers in two office buildings.

    PubMed Central

    Menzres, D; Tamblyn, R M; Nunes, F; Hanley, J; Tamblyn, R T

    1996-01-01

    OBJECTIVES: We hypothesized that exposure to contaminants would be associated with symptoms reported by office workers. METHODS: In two mechanically ventilated office buildings in. Montreal, the outdoor air supply was manipulated for 6 weeks, while symptoms were reported and environmental parameters were measured at multiple sites. RESULTS: Contaminant concentrations varied considerably, in part related to experimental changes in outdoor air supply. Eye symptoms were reported with higher dust and with higher concentrations of nitrogen dioxide. Mucosal symptoms were increased with higher TVOCs, higher nitrogen dioxide, and higher total contaminant load. Systemic symptoms were associated with higher dust levels. CONCLUSIONS: Symptoms reported by the workers were associated with increased concentrations of several contaminants and a summary measure of all contaminants. PMID:8916534

  20. Methodology for Modeling the Microbial Contamination of Air Filters

    PubMed Central

    Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

    2014-01-01

    In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter. PMID:24523908

  1. Biofiltration of trichloroethylene-contaminated air: a pilot study.

    PubMed

    Lackey, Laura W; Gamble, Johnny R; Boles, Jeffrey L

    2003-10-01

    This project demonstrated the biofiltration of a trichloroethylene (TCE)-contaminated airstream generated by air stripping groundwater obtained from several wells located at the Anniston Army Depot, Anniston, AL. The effects of several critical process variables were investigated to evaluate technical and economic feasibility, define operating limits and preferred operating conditions, and develop design information for a full-scale biofilter system. Long-term operation of the demonstration biofilter system was conducted to evaluate the performance and reliability of the system under variable weather conditions. Propane was used as the primary substrate necessary to induce the production of a nonspecific oxygenase. Results indicated that the process scheme used to introduce propane into the biofiltration system had a significant impact on the observed TCE removal efficiency. TCE degradation rates were dependent on the inlet contaminant concentration as well as on the loading rate. No microbial inhibition was observed at inlet TCE concentrations as high as 87 parts per million on a volume basis.

  2. contamination nucléaire par laser UV

    NASA Astrophysics Data System (ADS)

    Delaporte, Ph.; Gastaud, M.; Marine, W.; Sentis, M.; Uteza, O.; Thouvenot, P.; Alcaraz, J. L.; Le Samedy, J. M.; Blin, D.

    2003-06-01

    Le développement et l'utilisation de procédés propres pour le nettoyage ou la préparation de surfaces est l'une des priorités du milieu industriel. Cet intérêt est d'autant plus grand dans le domaine du nucléaire pour lequel la réduction des déchets est un axe de recherche important. Un dispositif de décontamination nucléaire par laser UV impulsionnel a été développé et testé. Il est composé. d'un laser à excimères de 1kW, d'un faisceau de fibres optiques et d'un dispositif de récupération des particules. Les essais réalisés en milieu actif ont démontré sa capacité à nettoyer des surfaces métalliques polluées par différents radioéléments avec des facteurs de décontamination généralement supérieurs à 10. Ce dispositif permet de décontaminer de grandes surfaces de géométrie simple en réduisant fortement la génération de déchets secondaires. Il est, à ce jour et dans ces conditions d'utilisations, le procédé de décontamination par voie sèche le plus efficace.

  3. Processing AIRS Scientific Data Through Level 2

    NASA Technical Reports Server (NTRS)

    Oliphant, Robert; Lee, Sung-Yung; Chahine, Moustafa; Susskind, Joel; arnet, Christopher; McMillin, Larry; Goldberg, Mitchell; Blaisdell, John; Rosenkranz, Philip; Strow, Larrabee

    2007-01-01

    The Atmospheric Infrared Spectrometer (AIRS) Science Processing System (SPS) is a collection of computer programs, denoted product generation executives (PGEs), for processing the readings of the AIRS suite of infrared and microwave instruments orbiting the Earth aboard NASA s Aqua spacecraft. AIRS SPS at an earlier stage of development was described in "Initial Processing of Infrared Spectral Data' (NPO-35243), NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 39. To recapitulate: Starting from level 0 (representing raw AIRS data), the PGEs and their data products are denoted by alphanumeric labels (1A, 1B, and 2) that signify the successive stages of processing. The cited prior article described processing through level 1B (the level-2 PGEs were not yet operational). The level-2 PGEs, which are now operational, receive packages of level-1B geolocated radiance data products and produce such geolocated geophysical atmospheric data products such as temperature and humidity profiles. The process of computing these geophysical data products is denoted "retrieval" and is quite complex. The main steps of the process are denoted microwave-only retrieval, cloud detection and cloud clearing, regression, full retrieval, and rapid transmittance algorithm.

  4. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13... part. The maximum contaminant levels for turbidity in drinking water, measured at a...

  5. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13... part. The maximum contaminant levels for turbidity in drinking water, measured at a...

  6. Cleaning contaminated soil using electrical heating and air stripping

    SciTech Connect

    Buettner, H.M.; Daily, W.D.

    1995-08-01

    In the summer of 1992, a proof-of-concept demonstration of direct electrical heating and air stripping was conducted for enhancing the removal of a volatile organic contaminant, trichloroethylene (TCSE), from soil. Six electrodes were buried in shallow boreholes so that a target region 6.1 m in diameter and 3.05 m in height was heated by ohmic dissipation of power-line-frequency electrical currents supplied by a diesel generator. Air stripping of TCE contamination from the same region was accomplished from a single well at the center of the heated volume. The electrical energy used during the demonstration was 3.46 {times} 10{sup 10} J (9,600 kW {center_dot} h), and the temperature of the extracted air rose from 16 C to 38 C. An energy balance shows that input energy is consistent with the temperature rise in the target volume and the amount of water vaporized at the electrodes. Prior to heating, the TCE concentration in the vapor decreased from about 80 parts per million by volume (ppm{sub v}) to around 60 ppm{sub v}. As soon as electrical heating started, TCE concentrations began to increase. Some concentration data were lost shortly after electrical heating began. After the system was repaired, the TCE concentration fell rapidly from about 140 ppm{sub v} to 5 ppm{sub v} over a period of about 25 days. A simple two-dimensional model for calculation of heating rates is also presented and verified experimentally. Finally some of the operation and safety issues associated with electrical heating are discussed.

  7. 40 CFR Appendix A1 to Subpart F of... - Generic Maximum Contaminant Levels

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Generic Maximum Contaminant Levels A1 Appendix A1 to Subpart F of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Recycling and Emissions Reduction Pt....

  8. 40 CFR Appendix A1 to Subpart F of... - Generic Maximum Contaminant Levels

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Generic Maximum Contaminant Levels A1 Appendix A1 to Subpart F of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Recycling and Emissions Reduction Pt....

  9. 40 CFR Appendix A1 to Subpart F of... - Generic Maximum Contaminant Levels

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Generic Maximum Contaminant Levels A1 Appendix A1 to Subpart F of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Recycling and Emissions Reduction Pt....

  10. 40 CFR Appendix A1 to Subpart F of... - Generic Maximum Contaminant Levels

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Generic Maximum Contaminant Levels A1 Appendix A1 to Subpart F of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Recycling and Emissions Reduction Pt....

  11. 40 CFR Appendix A1 to Subpart F of... - Generic Maximum Contaminant Levels

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Generic Maximum Contaminant Levels A1 Appendix A1 to Subpart F of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Recycling and Emissions Reduction Pt....

  12. Subsurface sediment contamination during borehole drilling with an air-actuated down-hole hammer.

    PubMed

    Malard, Florian; Datry, Thibault; Gibert, Janine

    2005-10-01

    Drilling methods can severely alter physical, chemical, and biological properties of aquifers, thereby influencing the reliability of water samples collected from groundwater monitoring wells. Because of their fast drilling rate, air-actuated hammers are increasingly used for the installation of groundwater monitoring wells in unconsolidated sediments. However, oil entrained in the air stream to lubricate the hammer-actuating device can contaminate subsurface sediments. Concentrations of total hydrocarbons, heavy metals (Cu, Ni, Cr, Zn, Pb, and Cd), and nutrients (particulate organic carbon, nitrogen, and phosphorus) were measured in continuous sediment cores recovered during the completion of a 26-m deep borehole drilled with a down-hole hammer in glaciofluvial deposits. Total hydrocarbons, Cu, Ni, Cr and particulate organic carbon (POC) were all measured at concentrations far exceeding background levels in most sediment cores. Hydrocarbon concentration averaged 124 +/- 118 mg kg(-1) dry sediment (n = 78 samples) with peaks at depths of 8, 14, and 20 m below the soil surface (maximum concentration: 606 mg kg(-1)). The concentrations of hydrocarbons, Cu, Ni, Cr, and POC were positively correlated and exhibited a highly irregular vertical pattern, that probably reflected variations in air loss within glaciofluvial deposits during drilling. Because the penetration of contaminated air into the formation is unpreventable, the representativeness of groundwater samples collected may be questioned. It is concluded that air percussion drilling has strong limitations for well installation in groundwater quality monitoring surveys.

  13. Reactive Distillation and Air Stripping Processes for Water Recycling and Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Reactive distillation designs are considered to reduce the presence of volatile organic compounds in the purified water. Reactive distillation integrates a reactor with a distillation column. A review of the literature in this field has revealed a variety of functional reactive columns in industry. Wastewater may be purified by a combination of a reactor and a distiller (e.g., the EWRS or VPCAR concepts) or, in principle, through a design which integrates the reactor with the distiller. A review of the literature in reactive distillation has identified some different designs in such combinations of reactor and distiller. An evaluation of reactive distillation and reactive air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  14. Wire-Mesh-Based Sorber for Removing Contaminants from Air

    NASA Technical Reports Server (NTRS)

    Perry, Jay; Roychoudhury, Subir; Walsh, Dennis

    2006-01-01

    A paper discusses an experimental regenerable sorber for removing CO2 and trace components principally, volatile organic compounds, halocarbons, and NH3 from spacecraft cabin air. This regenerable sorber is a prototype of what is intended to be a lightweight alternative to activated-carbon and zeolite-pellet sorbent beds now in use. The regenerable sorber consists mainly of an assembly of commercially available meshes that have been coated with a specially-formulated washcoat containing zeolites. The zeolites act as the sorbents while the meshes support the zeolite-containing washcoat in a configuration that affords highly effective surface area for exposing the sorbents to flowing air. The meshes also define flow paths characterized by short channel lengths to prevent excessive buildup of flow boundary layers. Flow boundary layer resistance is undesired because it can impede mass and heat transfer. The total weight and volume comparison versus the atmosphere revitalization equipment used onboard the International Space Station for CO2 and trace-component removal will depend upon the design details of the final embodiment. However, the integrated mesh-based CO2 and trace-contaminant removal system is expected to provide overall weight and volume savings by eliminating most of the trace-contaminant control equipment presently used in parallel processing schemes traditionally used for spacecraft. The mesh-based sorbent media enables integrating the two processes within a compact package. For the purpose of regeneration, the sorber can be heated by passing electric currents through the metallic meshes combined with exposure to space vacuum. The minimal thermal mass of the meshes offers the potential for reduced regeneration-power requirements and cycle time required for regeneration compared to regenerable sorption processes now in use.

  15. Indoor air contamination during a waterpipe (narghile) smoking session.

    PubMed

    Fromme, Hermann; Dietrich, Silvio; Heitmann, Dieter; Dressel, Holger; Diemer, Jürgen; Schulz, Thomas; Jörres, Rudolf A; Berlin, Knut; Völkel, Wolfgang

    2009-07-01

    The smoke of waterpipe contains numerous substances of health concern, but people mistakenly believe that this smoking method is less harmful and addictive than cigarettes. An experiment was performed in a 57 m3 room on two dates with no smoking on the first date and waterpipe smoking for 4h on the second date. We measured volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH), metals, carbon monoxide (CO), nitrogen oxides (e.g. NO), as well as particle mass (PM), particle number concentration (PNC) and particle surface area in indoor air. High concentrations were observed for the target analytes during the 4-h smoking event. The median (90th percentile) values of PM(2.5), PNC, CO and NO were 393 (737 microg/m(3)), 289,000 (550,000 particles/cm(3)), 51 (65 ppm) and 0.11 (0.13 ppm), respectively. The particle size distribution has a maximum of particles relating to a diameter of 17 nm. The seven carcinogenic PAH were found to be a factor 2.6 higher during the smoking session compared to the control day. In conclusion, the observed indoor air contamination of different harmful substances during a WP session is high, and exposure may pose a health risk for smokers but in particular for non-smokers who are exposed to ETS.

  16. Indoor air contamination during a waterpipe (narghile) smoking session.

    PubMed

    Fromme, Hermann; Dietrich, Silvio; Heitmann, Dieter; Dressel, Holger; Diemer, Jürgen; Schulz, Thomas; Jörres, Rudolf A; Berlin, Knut; Völkel, Wolfgang

    2009-07-01

    The smoke of waterpipe contains numerous substances of health concern, but people mistakenly believe that this smoking method is less harmful and addictive than cigarettes. An experiment was performed in a 57 m3 room on two dates with no smoking on the first date and waterpipe smoking for 4h on the second date. We measured volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH), metals, carbon monoxide (CO), nitrogen oxides (e.g. NO), as well as particle mass (PM), particle number concentration (PNC) and particle surface area in indoor air. High concentrations were observed for the target analytes during the 4-h smoking event. The median (90th percentile) values of PM(2.5), PNC, CO and NO were 393 (737 microg/m(3)), 289,000 (550,000 particles/cm(3)), 51 (65 ppm) and 0.11 (0.13 ppm), respectively. The particle size distribution has a maximum of particles relating to a diameter of 17 nm. The seven carcinogenic PAH were found to be a factor 2.6 higher during the smoking session compared to the control day. In conclusion, the observed indoor air contamination of different harmful substances during a WP session is high, and exposure may pose a health risk for smokers but in particular for non-smokers who are exposed to ETS. PMID:19394392

  17. Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California

    USGS Publications Warehouse

    Hothem, R.L.; Crayon, J.J.; Law, M.A.

    2006-01-01

    Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels-black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)-generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded

  18. Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California.

    PubMed

    Hothem, R L; Crayon, J J; Law, M A

    2006-11-01

    Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels--black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)--generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded

  19. Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California.

    PubMed

    Hothem, R L; Crayon, J J; Law, M A

    2006-11-01

    Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels--black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)--generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded

  20. AIR EMISSIONS FROM THE TREATMENT OF SOILS CONTAMINATED WITH PETROLEUM FUELS AND OTHER SUBSTANCES

    EPA Science Inventory

    The report updates a 1992 report that summarizes available information on air emissions from the treatment of soils contaminated with fuels. Soils contaminated by leaks or spills of fuel products, such as gasoline or jet fuel, are a nationwide concern. Air emissions during remedi...

  1. Molecular and ionic contamination monitoring for cleanroom air and wafer surfaces

    NASA Astrophysics Data System (ADS)

    Sun, Peng; Adams, Marty; Shive, Larry; Pirooz, Saeed

    1997-09-01

    Advances in the electronic industry toward large-scale integration of semiconductor devices have placed strict demands on the ability to measure and monitor ultratrace levels of impurities. Even though they have been found to have increasingly detrimental impacts on the performance and yield of semiconductor products, organic and non-metal ionic contaminants have not received the same attention as particles and metallics. Method developments for ultratrace measurements of molecular and ionic contamination are far behind the demands. This paper describes the use of different sampling and analytical techniques to assess and monitor molecular and ionic contaminants in cleanroom ambient air and on wafer surfaces. Thermal desorption gas chromatography mass spectrometry/nitrogen phosphorous detector is used for the identification and quantification of organic contaminants. Ammonium (NH4+) and inorganic anions are analyzed by using capillary electrophoresis with indirect UV detection methods. The identification and quantification of specific organic compounds, which outgas from cleanroom ULPA filters and wafer package boxes and tend to adsorb on silicon wafers, will be demonstrated. Ammonium and anion contamination for different wafer cleaning processes will be compared. The capabilities, applications, and limitations of these techniques will be discussed in further details.

  2. Well site conditions associated with nitrate contamination in a multilayer semiconfined aquifer of Buenos Aires, Argentina

    NASA Astrophysics Data System (ADS)

    Carbó, L. I.; Flores, M. C.; Herrero, M. A.

    2009-06-01

    A stepwise logistic regression (LR) model was generated to evaluate the association between contamination of groundwater by nitrates with several risk factors such as soil types, farm facilities and practises, and well characteristics. The odds ratio was calculated to estimate the degree of impact that the associated variables had on the risk of contamination in a semiconfined multilayer aquifer underlying rural areas of Buenos Aires, Argentina. Duplicate farm groundwater samples ( n = 160) were taken and nitrate was analyzed. Data, involving various farm factors, was gathered via two questionnaires concerning farm’s general and productive aspects, and well characteristics. Statistical tests were run between nitrates and each variable present in the survey. A 96.25% of the samples presented detectable nitrate levels, 40.91% of which had more than 45 ppm nitrates. The final LR model involved five of the variables under study: well age, soil permeability, depth of water table, location, and distance from well to contamination sources. Cross validation proved to be a good estimator of nitrate water contamination. Suspicions about how these characteristics influence groundwater contamination by nitrates were confirmed, and as these five factors represent a higher risk for this type of aquifer, their proper management may contribute to a better resource protection.

  3. Automatic Measurement of Low Level Contamination on Concrete Surfaces

    SciTech Connect

    Tachibana, M.; Itoh, H.; Shimada, T.; Yanagihara, S.

    2002-02-28

    Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm2 for 60Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m2/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application.

  4. Eyewear contamination levels in the operating room: infection risk.

    PubMed

    Lange, Victor R

    2014-04-01

    We investigated eyewear contamination levels in the operating room to assess infection risk and inform protocol development. Microbial contamination after use was found in 37.7% of disposable and 94.9% of reusable eyewear pieces. After disinfection, 74.4% of reusable eyewear also cultured positive. Disposable eyewear may reduce intercase contamination risk. Reusable eyewear may carry ongoing bioburden and, thus, contribute to operating room environment risk. Eyewear with antimicrobial material or components could reduce risk. Alternative decontamination methods for reusable eyewear should be evaluated.

  5. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB) initiated an effort for the evaluation of potential removal of ground water contamination at the Base. This report presents a current assessment of the nature and extent of the contamination believed to be migrating across the southwestern boundary of Area C and the northern boundary of Area B based upon analysis of existing environmental data obtained from several sources. The existing data base indicates widespread, low-level contamination moving across Base boundaries at levels that pose no immediate threat to the Mad River Valley well fields. An investigation by the City of Dayton in May and June 1990, however, implies that a more identifiable plume of PCE and TCE may be crossing the southwestern boundary of Area C immediately downgradient of Landfill 5. More data is needed to delineate ground water contamination and to design and implement a suitable control system. This report concludes that although an extensive study of the boundaries in question would be the preferred approach, a limited, focused investigation and subsequent feasibility study can be accomplished with a reasonable certainty of achieving the desired outcome of this project.

  6. Comparison of Microbial Contamination Levels Among Hospital Operating Rooms and Industrial Clean Rooms

    PubMed Central

    Favero, Martin S.; Puleo, John R.; Marshall, James H.; Oxborrow, Gordon S.

    1968-01-01

    Microbial contamination in industrial clean rooms was compared quantitatively and qualitatively with that of hospital operating rooms. The number of aerobic mesophilic microorganisms which accumulated on stainless-steel strips exposed for periods up to 21 weeks to the intramural air of four operating rooms was at least 1 log higher than the accumulation on strips exposed in four clean rooms, and was essentially the same as that found in two factory areas. Volumetric air samplings showed that there were significantly higher numbers of airborne viable particles per cubic foot of air in operating rooms than in industrial clean rooms. In contrast to clean rooms, where most of the airborne contaminants were those associated with human hair, skin, and respiratory tract, the hospital operating rooms showed a very high level of microorganisms associated with dust and soil. Images Fig. 4 PMID:5649862

  7. Contamination of the air with mineral fibers following the explosive destruction of buildings and fire.

    PubMed

    Hoskins, J A; Brown, R C

    1994-01-01

    Mineral fibers, including asbestos, are ubiquitous contaminants of the environment. Asbestos fibers are generally present at levels below 1 fiber/L in air though 10 fibers/L may be found in cities; these levels do not appear to be high enough to present a hazard to health. These fibers come mostly from the use of fibrous materials as thermal and acoustic insulation in buildings, and their use as friction materials. Historically, occupational air levels were often very high and as a result there was a high incidence of fibrosis and also cancer in exposed workers, mostly among those in the industries concerned with the winning or processing of asbestos fiber. Levels high enough to produce disease have also occurred paraoccupationally in the families of asbestos workers. The effect of fire and explosion in a building is to disrupt its structure and vastly increase the level of airborne fiber for a considerable distance (kilometers) around it. Air levels of fiber can remain high for months, and as a result the earliest occupational experiences are likely to be repeated. The greatest danger is from exposure to blue and brown asbestos, and it is known that even a single high exposure can be responsible for the development of a tumor decades later.

  8. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... levels for radionuclides. (a) (b) MCL for combined radium-226 and -228. The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/L. The combined radium-226 and radium-228 value is...

  9. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... levels for radionuclides. (a) (b) MCL for combined radium-226 and -228. The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/L. The combined radium-226 and radium-228 value is...

  10. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... levels for radionuclides. (a) (b) MCL for combined radium-226 and -228. The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/L. The combined radium-226 and radium-228 value is...

  11. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... levels for radionuclides. (a) (b) MCL for combined radium-226 and -228. The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/L. The combined radium-226 and radium-228 value is...

  12. 40 CFR 141.66 - Maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... levels for radionuclides. (a) (b) MCL for combined radium-226 and -228. The maximum contaminant level for combined radium-226 and radium-228 is 5 pCi/L. The combined radium-226 and radium-228 value is...

  13. Lead and cadmium contamination levels in edible vegetables

    SciTech Connect

    Zurera, G.; Estrada, B.; Rincon, F.; Pozo, R.

    1987-05-01

    The objective of this research is to reveal the level of lead and cadmium pollution in fresh vegetable samples from the Cordovan fertile lowland region of the Guadalquivir River and to establish a base level of contamination to serve as a reference point in further studies. At the same time, the possible health risks for the consumer are discussed.

  14. Hospital ventilation standards and energy conservation: chemical contamination of hospital air. Final report

    SciTech Connect

    Rainer, D.; Michaelsen, G.S.

    1980-03-01

    In an era of increasing energy conservation consciousness, a critical reassessment of the validity of hospital ventilation and thermal standards is made. If current standards are found to be excessively conservative, major energy conservation measures could be undertaken by rebalancing and/or modification of current HVAC systems. To establish whether or not reducing ventilation rates would increase airborne chemical contamination to unacceptable levels, a field survey was conducted to develop an inventory and dosage estimates of hospital generated airborne chemical contaminants to which patients, staff, and visitors are exposed. The results of the study are presented. Emphasis is on patient exposure, but an examination of occupational exposure was also made. An in-depth assessment of the laboratory air environment is documented. Housekeeping products used in survey hospitals, hazardous properties of housekeeping chemicals and probable product composition are discussed in the appendices.

  15. Three-dimensional modeling, estimation, and fault diagnosis of spacecraft air contaminants.

    PubMed

    Narayan, A P; Ramirez, W F

    1998-01-01

    A description is given of the design and implementation of a method to track the presence of air contaminants aboard a spacecraft using an accurate physical model and of a procedure that would raise alarms when certain tolerance levels are exceeded. Because our objective is to monitor the contaminants in real time, we make use of a state estimation procedure that filters measurements from a sensor system and arrives at an optimal estimate of the state of the system. The model essentially consists of a convection-diffusion equation in three dimensions, solved implicitly using the principle of operator splitting, and uses a flowfield obtained by the solution of the Navier-Stokes equations for the cabin geometry, assuming steady-state conditions. A novel implicit Kalman filter has been used for fault detection, a procedure that is an efficient way to track the state of the system and that uses the sparse nature of the state transition matrices. PMID:11543186

  16. Calculation of isotope-specific exemption levels for surface contamination.

    PubMed

    Ogino, Haruyuki; Hattori, Takatoshi

    2009-01-01

    Isotope-specific exemption levels for surface contamination are calculated for representative radionuclides in general nuclear power plants by developing a deterministic dose assessment model for surface contamination that can be applied to radiation, transport and waste safety, and a practical idea of judging exemption for gross surface contamination by measuring gross gamma-ray emission has been proposed. In the dose assessment model, the objects with surface contamination are classified into three types: manually handled, closely handled and remotely handled objects, and the exemption criteria are chosen to be 0.01mSv/yr in the case of using realistic exposure parameters and 1mSv/yr in the case of using low-probability exposure parameters in accordance with the IAEA Safety Standards Series No. RS-G-1.7. Taking into account the distribution area of surface contamination assumed in the dose assessment model, instead of using the evaluation area of 100cm(2) without variation, the exemption levels for gross surface contamination are found to be higher than those obtained by the conventional method for some radionuclides such as Mn-54, Co-60, Zn-65, Nb-94, Cs-134, Cs-137, Eu-152 and Eu-154.

  17. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum... pose an acute risk to health. (c) A public water system must determine compliance with the MCL...

  18. 40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum... pose an acute risk to health. (c) A public water system must determine compliance with the MCL...

  19. Levels of chlorinated, brominated, and perfluorinated contaminants in birds of prey spanning multiple trophic levels.

    PubMed

    Yordy, Jennifer E; Rossman, Sam; Ostrom, Peggy H; Reiner, Jessica L; Bargnesi, Keely; Hughes, Stacy; Elliot, James D

    2013-04-01

    Birds of prey occupy high trophic levels and can consequently bioaccumulate high levels of environmental contaminants. To evaluate exposure to past- and current-use pollutants, we measured legacy contaminants (i.e., polychlorinated biphenyls [PCBs]; organochlorine pesticides, e.g., DDT), contaminants of emerging concern (polybrominated diphenyl ethers [PBDEs]; perfluorinated compounds [PFCs]), and stable isotopes (δ(13)C, δ(15)N) in 26 birds of prey (10 species) from coastal South Carolina (USA) sampled in 2009 and 2010. Nitrogen isotope ratios (δ(15)N) ranged from 5.2% to 13.7%, indicating the birds of prey spanned two to three trophic levels. Legacy contaminant levels were highly variable but generally comparable to levels reported previously for birds of prey in the southeast US, suggesting exposure has not declined substantially over the past 40 yr. Despite their status as newly emerging environmental contaminants, PFC levels were within the same order of magnitude as legacy contaminants. Although PBDEs were less prevalent, levels were among the greatest observed in wildlife to date (∑PBDEs max. 200 μg/g lipid). Relative contaminant profiles also varied between birds of prey utilizing low and high trophic levels; specifically PFCs contributed to a larger proportion of the contaminant burden in birds utilizing high trophic levels, whereas the legacy pesticide mirex was a larger contributor in low-trophic-level birds, indicating that relative exposure is in part dependent on foraging ecology. This study demonstrates that birds of prey continue to face exposure to legacy contaminants as well as newly emerging contaminants at levels of concern. PMID:23568910

  20. Monitoring Trace Contaminants in Air Via Ion Trap Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Palmer, Peter T.; Karr, Dane; Pearson, Richard; Valero, Gustavo; Wong, Carla

    1995-01-01

    Recent passage of the Clean Air Act with its stricter regulation of toxic gas emissions, and the ever-growing number of applications which require faster turnaround times between sampling and analysis are two major factors which are helping to drive the development of new instrument technologies for in-situ, on-line, real-time monitoring. The ion trap, with its small size, excellent sensitivity, and tandem mass spectrometry capability is a rapidly evolving technology which is well-suited for these applications. In this paper, we describe the use of a commercial ion trap instrument for monitoring trace levels of chlorofluorocarbons (CFCs) and volatile organic compounds (VOCs) in air. A number of sample introduction devices including a direct transfer line interface, short column GC, and a cryotrapping interface are employed to achieve increasing levels of sensitivity. MS, MS/MS, and MS/MS/MS methods are compared to illustrate trade-offs between sensitivity and selectivity. Filtered Noise Field (FNF) technology is found to be an excellent means for achieving lower detection limits through selective storage of the ion(s) of interest during ionization. Figures of merit including typical sample sizes, detection limits, and response times are provided. The results indicate the potential of these techniques for atmospheric assessments, the High Speed Research Program, and advanced life support monitoring applications for NASA.

  1. Contaminant levels in fish tissue from San Francisco Bay

    SciTech Connect

    Fairey, R.; Taberski, K.

    1995-12-31

    Edible fish species were collected from thirteen locations throughout San Francisco Bay, during the spring of 1994, for determination of contaminants levels in muscle tissue. Species collected included white croaker, surfperch, leopard and brown smoothhound sharks, striped bass, white sturgeon and halibut Sixty six composite tissue samples were analyzed for the presence of PAHs, PCBs, pesticides, trace elements and dioxin/furans. The US EPA approach to assessing chemical contaminant data for fish tissue consumption was used for identifying the primary chemicals of concern. Six chemicals or chemical groups were found to exceed screening levels established using the US EPA approach. PCBs (as total Aroclors) exceeded the screening level of 3 ppb in all sixty six tissue samples, with the highest concentrations (638 ppb) found near San Francisco`s industrial areas. Mercury was elevated (> 0.14 ppm) in forty of the sixty-six samples with the highest levels (1.26 ppm) occurring in shark muscle tissues. Concentrations of the organochlorine pesticides dieldrin, total chlordanes and total DDTs exceeded screening levels in a number of samples. Dioxin/furans (as TEQs) were elevated (above 0.15 ppt) in 16 of the 19 samples analyzed. Fish with high lipid content (croaker and surfperch) in their muscle tissue generally exhibited higher contaminant levels while fish with low lipid levels (halibut and shark) exhibited lower organic contaminant levels. Tissue samples taken from North Bay stations most often exhibited high levels of chemical contamination. The California Office of Health Hazard Assessment is currently evaluating the results of this study and has issued an interim Health Advisory concerning the human consumption of fish tissue from San Francisco Bay.

  2. Environmental contaminants of emerging concern in seafood--European database on contaminant levels.

    PubMed

    Vandermeersch, Griet; Lourenço, Helena Maria; Alvarez-Muñoz, Diana; Cunha, Sara; Diogène, Jorge; Cano-Sancho, German; Sloth, Jens J; Kwadijk, Christiaan; Barcelo, Damia; Allegaert, Wim; Bekaert, Karen; Fernandes, José Oliveira; Marques, Antonio; Robbens, Johan

    2015-11-01

    Marine pollution gives rise to concern not only about the environment itself but also about the impact on food safety and consequently on public health. European authorities and consumers have therefore become increasingly worried about the transfer of contaminants from the marine environment to seafood. So-called "contaminants of emerging concern" are chemical substances for which no maximum levels have been laid down in EU legislation, or substances for which maximum levels have been provided but which require revision. Adequate information on their presence in seafood is often lacking and thus potential risks cannot be excluded. Assessment of food safety issues related to these contaminants has thus become urgent and imperative. A database (www.ecsafeseafooddbase.eu), containing available information on the levels of contaminants of emerging concern in seafood and providing the most recent data to scientists and regulatory authorities, was developed. The present paper reviews a selection of contaminants of emerging concern in seafood including toxic elements, endocrine disruptors, brominated flame retardants, pharmaceuticals and personal care products, polycyclic aromatic hydrocarbons and derivatives, microplastics and marine toxins. Current status on the knowledge of human exposure, toxicity and legislation are briefly presented and the outcome from scientific publications reporting on the levels of these compounds in seafood is presented and discussed.

  3. Effect of groundwater flow on remediation of dissolved-phase VOC contamination using air sparging.

    PubMed

    Reddy, K R; Adams, J A

    2000-02-25

    This paper presents two-dimensional laboratory experiments performed to study how groundwater flow may affect the injected air zone of influence and remedial performance, and how injected air may alter subsurface groundwater flow and contaminant migration during in situ air sparging. Tests were performed by subjecting uniform sand profiles contaminated with dissolved-phase benzene to a hydraulic gradient and two different air flow rates. The results of the tests were compared to a test subjected to a similar air flow rate but a static groundwater condition. The test results revealed that the size and shape of the zone of influence were negligibly affected by groundwater flow, and as a result, similar rates of contaminant removal were realized within the zone of influence with and without groundwater flow. The air flow, however, reduced the hydraulic conductivity within the zone of influence, reducing groundwater flow and subsequent downgradient contaminant migration. The use of a higher air flow rate further reduced the hydraulic conductivity and decreased groundwater flow and contaminant migration. Overall, this study demonstrated that air sparging may be effectively implemented to intercept and treat a migrating contaminant plume.

  4. Fast detection of air contaminants using immunobiological methods

    NASA Astrophysics Data System (ADS)

    Schmitt, Katrin; Bolwien, Carsten; Sulz, Gerd; Koch, Wolfgang; Dunkhorst, Wilhelm; Lödding, Hubert; Schwarz, Katharina; Holländer, Andreas; Klockenbring, Torsten; Barth, Stefan; Seidel, Björn; Hofbauer, Wolfgang; Rennebarth, Torsten; Renzl, Anna

    2009-05-01

    The fast and direct identification of possibly pathogenic microorganisms in air is gaining increasing interest due to their threat for public health, e.g. in clinical environments or in clean rooms of food or pharmaceutical industries. We present a new detection method allowing the direct recognition of relevant germs or bacteria via fluorescence-labeled antibodies within less than one hour. In detail, an air-sampling unit passes particles in the relevant size range to a substrate which contains antibodies with fluorescence labels for the detection of a specific microorganism. After the removal of the excess antibodies the optical detection unit comprising reflected-light and epifluorescence microscopy can identify the microorganisms by fast image processing on a single-particle level. First measurements with the system to identify various test particles as well as interfering influences have been performed, in particular with respect to autofluorescence of dust particles. Specific antibodies for the detection of Aspergillus fumigatus spores have been established. The biological test system consists of protein A-coated polymer particles which are detected by a fluorescence-labeled IgG. Furthermore the influence of interfering particles such as dust or debris is discussed.

  5. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13... both community water systems and non-community water systems using surface water sources in whole or...

  6. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13... both community water systems and non-community water systems using surface water sources in whole or...

  7. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum contaminant levels for turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER...) Interfere with disinfection; (2) Prevent maintenance of an effective disinfectant agent throughout...

  8. 40 CFR 143.3 - Secondary maximum contaminant levels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant.... Zinc 5 mg/l. These levels represent reasonable goals for drinking water quality. The States...

  9. 40 CFR 143.3 - Secondary maximum contaminant levels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant.... Zinc 5 mg/l. These levels represent reasonable goals for drinking water quality. The States...

  10. 40 CFR 143.3 - Secondary maximum contaminant levels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant.... Zinc 5 mg/l. These levels represent reasonable goals for drinking water quality. The States...

  11. 40 CFR 143.3 - Secondary maximum contaminant levels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant.... Zinc 5 mg/l. These levels represent reasonable goals for drinking water quality. The States...

  12. 40 CFR 143.3 - Secondary maximum contaminant levels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant.... Zinc 5 mg/l. These levels represent reasonable goals for drinking water quality. The States...

  13. Assessment of exposure to indoor air contaminants from combustion sources: methodology and application.

    PubMed

    Leaderer, B P; Zagraniski, R T; Berwick, M; Stolwijk, J A

    1986-08-01

    A methodology for assessing indoor air pollutant exposures is presented, with specific application to unvented combustion by-products. This paper describes the method as applied to a study of acute respiratory illness associated with the use of unvented kerosene space heaters in 333 residences in the New Haven, Connecticut, area from September 1982 to April 1983. The protocol serves as a prototype for a nested design of exposure assessment which could be applied to large-scale field studies of indoor air contaminant levels. Questionnaires, secondary records, and several methods of air monitoring offer a reliable method of estimating environmental exposures for assessing associations with health effects at a reasonable cost. Indoor to outdoor ratios of NO2 concentrations were found to be 0.58 +/- 0.31 for residences without known sources of NO2. Levels of NO2 were found to be comparable for homes with a kerosene heater only and those with a gas cooking stove only. Homes with a kerosene heater and a gas stove had average two-week NO2 levels approximately double those with only one source. Presence of tobacco smokers had a small but significant impact on indoor NO2 levels. Two-week average levels of indoor NO2 were found to be excellent predictors of total personal NO2 exposure for a small sample of adults. Residences with kerosene space heaters had SO2 levels corresponding to the number of hours of heater use and the sulfur content of the fuel. Formaldehyde levels were found to be low and not related to unvented combustion sources. NO2, SO2, and CO2 levels measured in some of the residences were found to exceed those levels specified in current national health standards.

  14. Assessing Aircraft Supply Air to Recommend Compounds for Timely Warning of Contamination

    NASA Astrophysics Data System (ADS)

    Fox, Richard B.

    Taking aircraft out of service for even one day to correct fume-in-cabin events can cost the industry roughly $630 million per year in lost revenue. The quantitative correlation study investigated quantitative relationships between measured concentrations of contaminants in bleed air and probability of odor detectability. Data were collected from 94 aircraft engine and auxiliary power unit (APU) bleed air tests from an archival data set between 1997 and 2011, and no relationships were found. Pearson correlation was followed by regression analysis for individual contaminants. Significant relationships of concentrations of compounds in bleed air to probability of odor detectability were found (p<0.05), as well as between compound concentration and probability of sensory irritancy detectability. Study results may be useful to establish early warning levels. Predictive trend monitoring, a method to identify potential pending failure modes within a mechanical system, may influence scheduled down-time for maintenance as a planned event, rather than repair after a mechanical failure and thereby reduce operational costs associated with odor-in-cabin events. Twenty compounds (independent variables) were found statistically significant as related to probability of odor detectability (dependent variable 1). Seventeen compounds (independent variables) were found statistically significant as related to probability of sensory irritancy detectability (dependent variable 2). Additional research was recommended to further investigate relationships between concentrations of contaminants and probability of odor detectability or probability of sensory irritancy detectability for all turbine oil brands. Further research on implementation of predictive trend monitoring may be warranted to demonstrate how the monitoring process might be applied to in-flight application.

  15. Remediation of saturated soil contaminated with petroleum products using air sparging with thermal enhancement.

    PubMed

    Mohamed, A M I; El-menshawy, Nabil; Saif, Amany M

    2007-05-01

    Pollutants in the form of non-aqueous phase liquids (NAPLs), such as petroleum products, pose a serious threat to the soil and groundwater. A mathematical model was derived to study the unsteady pollutant concentrations through water saturated contaminated soil under air sparging conditions for different NAPLs and soil properties. The comparison between the numerical model results and the published experimental results showed acceptable agreement. Furthermore, an experimental study was conducted to remove NAPLs from the contaminated soil using the sparging air technique, considering the sparging air velocity, air temperature, soil grain size and different contaminant properties. This study showed that sparging air at ambient temperature through the contaminated soil can remove NAPLs, however, employing hot air sparging can provide higher contaminant removal efficiency, by about 9%. An empirical correlation for the volatilization mass transfer coefficient was developed from the experimental results. The dimensionless numbers used were Sherwood number (Sh), Peclet number (Pe), Schmidt number (Sc) and several physical-chemical properties of VOCs and porous media. Finally, the estimated volatilization mass transfer coefficient was used for calculation of the influence of heated sparging air on the spreading of the NAPL plume through the contaminated soil.

  16. Air Sampling Instruments for Evaluation of Atmospheric Contaminants. Fourth Edition.

    ERIC Educational Resources Information Center

    American Conference of Governmental Industrial Hygienists, Cincinnati, OH.

    This text, a revision and extension of the first three editions, consists of papers discussing the basic considerations in sampling air for specific purposes, sampler calibration, systems components, sample collectors, and descriptions of air-sampling instruments. (BT)

  17. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  18. Evolution of Fuel-Air and Contaminant Clouds Resulting from a Cruise Missile Explosion Scenario

    SciTech Connect

    Grossman, A S; Kul, A L

    2005-06-22

    A low-mach-number hydrodynamics model has been used to simulate the evolution of a fuel-air mixture and contaminant cloud resulting from the detonation of a cruise missile. The detonation has been assumed to be non-nuclear. The cloud evolution has been carried out to a time of 5.5 seconds. At this time the contaminant has completely permeated the initial fuel-air mixture cloud.

  19. Removal of contaminated air scrubbers at TA-35-7, Los Alamos National Laboratory

    SciTech Connect

    Harper, J.R.; Garde, R.

    1981-11-01

    Five large excess contaminated air scrubbers located in Building 7 at TA-35 were removed and disposed of in 1979 to 1980. The scrubbers were contaminated with strontium-yttrium and cesium. This report details the removal procedures, the health physics program, the waste management program, and the costs of the operation.

  20. Use of Source Term and Air Dispersion Modeling in Planning Demolition of Highly Alpha-Contaminated Buildings

    SciTech Connect

    Droppo, James G.; Napier, Bruce A.; Rishel, Jeremy P.; Bloom, Richard W.

    2011-06-22

    The current cleanup of structures related to cold-war production of nuclear materials includes the need to demolish a number of highly alpha-contaminated structures. The process of planning for the demolition of such structures includes unique challenges related to ensuring the protection of both workers and the public. Pre-demolition modeling analyses were conducted to evaluate potential exposures resulting from the proposed demolition of a number of these structures. Estimated emission rates of transuranic materials during demolition are used as input to an air-dispersion model. The climatological frequencies of occurrence of peak air and surface exposures at locations of interest are estimated based on years of hourly meteorological records. The modeling results indicate that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. The pre-demolition modeling directed the need for better contamination characterization and/or different demolition methods—and in the end, provided a basis for proceeding with the planned demolition activities. Post-demolition modeling was also conducted for several contaminated structures, based on the actual demolition schedule and conditions. Comparisons of modeled and monitoring results are shown. Recent monitoring data from the demolition of a UO3 plant shows increments in concentrations that were previously identified in the pre-demolition modeling predictions; these comparisons confirm the validity and value of the pre-demolition source-term and air dispersion computations for planning demolition activities for other buildings with high levels of radioactive contamination.

  1. 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.

  2. A SURVEY OF INDOOR AIR CONTAMINATES USING SEMIPERMEABLE MEMBRANE DEVICES

    EPA Science Inventory

    Semipermeable membrane devices (SPMDs) were deployed in indoor areas in approximately 50 residences along the border between Arizona and Mexico to measure airborne contaminants. The results of the primary analyses and gas chromatographic/mass spectrometric confirmation for org...

  3. Air contaminant statistical distributions with application to PM10 in Santiago, Chile.

    PubMed

    Marchant, Carolina; Leiva, Víctor; Cavieres, M Fernanda; Sanhueza, Antonio

    2013-01-01

    The use of statistical distributions to predict air quality is valuable for determining the impact of air chemical contaminants on human health. Concentrations of air pollutants are treated as random variables that can be modeled by a statistical distribution that is positively skewed and starts from zero. The type of distribution selected for analyzing air pollution data and its associated parameters depend on factors such as emission source and local meteorology and topography. International environmental guideline use appropriate distributions to compute exceedance probabilities and percentiles for setting administrative targets and issuing environmental alerts. The distribution bears a relationship to the normal distribution, and there are theoretical - and physical-based mechanistic arguments that support its use when analyzing air-pollutant data. Others distribution have also been used to model air population data, such as the beta, exponential, gamma, Johnson, log-logistic, Pearson, and Weibull distribution. One model also developed from physical-mechanistic considerations that has received considerable interest in recent year is the Birnbaum-Saunders distribution. This distribution has theoretical arguments and properties similar to those of the log-normal distribution, which renders it useful for modeling air contamination data. In this review, we have addressed the range of common atmospheric contaminants and the health effects they cause. We have also reviewed the statistical distributions that have been use to model air quality, after which we have detailed the problem of air contamination in Santiago, Chile. We have illustrated a methodology that is based on the Birnbaum-Saunders distributions to analyze air contamination data from Santiago, Chile. Finally, in the conclusions, we have provided a list of synoptic statements designed to help readers understand the significance of air pollution in Chile, and in Santiago, in particular, but that can be

  4. Reading Grade Levels of Air Force Civilian Personnel.

    ERIC Educational Resources Information Center

    Massey, Randy H.; Mathews, John J.

    A study was conducted to examine the reading levels of United States Air Force civilian employees according to occupational groupings and grade structure. Approximately 1,050 Air Force civilian subjects were tested on the Nelson-Denny Reading Test or the California Reading Test. Subjects were selected from eight Air Force bases representing the…

  5. 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.

  6. Micellar-enhanced ultrafiltration and air stripping for surfactant-contaminant separation and surfactant reuse

    SciTech Connect

    Lipe, K.M.; Sabatini, D.A.; Hasegawa, M.A.; Harwell, J.H.

    1996-05-01

    Micellar-enhanced ultrafiltration (MEUF) and air stripping were evaluated for surfactant-contaminant separation and surfactant recovery. Two linear alkyl diphenyloxide disulfonate (DPDS) surfactants were evaluated with the contaminants naphthalene and trichloroethylene. A separation model developed from micellar partitioning principles showed a good correlation to batch MEUF studies, whereas flux analysis highlighted concentration polarization effects in relation to hydrophobe length. MEUF effectively concentrated the surfactant-contaminant system (93 to 99% retention); however, this did not result in surfactant-contaminant separation. Batch and continuous flow air stripping models were developed based upon air/water ratio, surfactant concentration, and micellar partitioning; model predictions were validated by experimental data. Sensitivity analyses illustrated the decline in contaminant-surfactant separation with increasing surfactant concentration (e.g., TCE removal efficiency declines from 83% to 37% as C-16 DPDS concentration increases from 0 to 55 mM). This effect is greater for more hydrophobic contaminants (naphthalene vs. TCE) and surfactants with greater solubilization potential (C16-DPDS vs. C-12 DPDS). The resulting design equations can account for this effect and thus properly size air strippers to achieve the desired removal efficiency in the presence of surfactant micelles. Proper selection and design of surfactant-contaminant separation and surfactant recovery systems are integral to optimizing surfactant-enhanced subsurface remediation.

  7. Removal of volatile and semivolatile organic contamination from soil by air and steam flushing.

    PubMed

    Sleep, B E; McClure, P D

    2001-07-01

    A soil core, obtained from a contaminated field site, contaminated with a mixture of volatile and semivolatile organic compounds (VOC and SVOC) was subjected to air and steam flushing. Removal rates of volatile and semivolatile organic compounds were monitored during flushing. Air flushing removed a significant portion of the VOC present in the soil, but a significant decline in removal rate occurred due to decreasing VOC concentrations in the soil gas phase. Application of steam flushing after air flushing produced a significant increase in contaminant removal rate for the first 4 to 5 pore volumes of steam condensate. Subsequently, contaminant concentrations decreased slowly with additional pore volumes of steam flushing. The passage of a steam volume corresponding to 11 pore volumes of steam condensate reduced the total VOC concentration in the soil gas (at 20 degrees C) by a factor of 20 to 0.07 mg/l. The corresponding total SVOC concentration in the condensate declined from 11 to 3 mg/l. Declines in contaminant removal rates during both air and steam flushing indicated rate-limited removal consistent with the persistence of a residual organic phase, rate-limited desorption, or channeling. Pressure gradients were much higher for steam flushing than for air flushing. The magnitude of the pressure gradients encountered during steam flushing for this soil indicates that, in addition to rate-limited contaminant removal, the soil permeability (2.1 x 10(-9) cm2) would be a limiting factor in the effectiveness of steam flushing. PMID:11475159

  8. [Microbial contamination of the air in the commercial production of poultry meat].

    PubMed

    Baĭkov, B D; Petkov, G

    1987-01-01

    Microbiologic studies were carried out on industrial premises for the raising of broiler birds on deep litter over a flooring area of 2000 m2 at mechanical ventilation of negative pressure. The microbial count was established through culturing in meat-and-peptone agar regarding the presence of coli bacteria, microscopic fungi, hemolytic cocci and Salmonellae in the air. Studies were also performed to establish the contamination of the atmospheric air at a distance of 10 m surrounding the premises, of the litter as well as of the feed and the soil in immediate proximity to the buildings. It was found that as a result of raising the 'biologic loading' of the ecotope by 60 per cent the microbial contamination of the air in the industrial buildings rose. The basic sources of contamination were the deep litter, the atmospheric air introduced by the ventilation system, the soil, and the feed.

  9. 40 CFR 52.1988 - Air contaminant discharge permits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... other requirements of the SIP. Plant site emission limits and alternative emission limits (bubbles... Emission Limits for Sources of Hazardous Air Pollutants” and 060(8) “Alternative Emission Controls...

  10. 40 CFR 52.1988 - Air contaminant discharge permits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... other requirements of the SIP. Plant site emission limits and alternative emission limits (bubbles... Emission Limits for Sources of Hazardous Air Pollutants” and 060(8) “Alternative Emission Controls...

  11. 40 CFR 52.1988 - Air contaminant discharge permits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... other requirements of the SIP. Plant site emission limits and alternative emission limits (bubbles... Emission Limits for Sources of Hazardous Air Pollutants” and 060(8) “Alternative Emission Controls...

  12. 40 CFR 52.1988 - Air contaminant discharge permits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... other requirements of the SIP. Plant site emission limits and alternative emission limits (bubbles... Emission Limits for Sources of Hazardous Air Pollutants” and 060(8) “Alternative Emission Controls...

  13. 40 CFR 52.1988 - Air contaminant discharge permits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... other requirements of the SIP. Plant site emission limits and alternative emission limits (bubbles... Emission Limits for Sources of Hazardous Air Pollutants” and 060(8) “Alternative Emission Controls...

  14. Effects of water-contaminated air on blowoff limits of opposed jet hydrogen-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Pellett, Gerald L.; Jentzen, Marilyn E.; Wilson, Lloyd G.; Northam, G. Burton

    1988-01-01

    The effects of water-contaminated air on the extinction and flame restoration of the central portion of N2-diluted H2 versus air counterflow diffusion flames are investigated using a coaxial tubular opposed jet burner. The results show that the replacement of N2 contaminant in air by water on a mole for mole basis decreases the maximum sustainable H2 mass flow, just prior to extinction, of the flame. This result contrasts strongly with the analogous substitution of water for N2 in a relatively hot premixed H2-O2-N2 flame, which was shown by Koroll and Mulpuru (1986) to lead to a significant, kinetically controlled increase in laminar burning velocity.

  15. Effects of breathing air containing contaminants such as CO/sub 2/, CO and hydrocarbons at 1 and 5 atmospheres

    SciTech Connect

    Benignus, V.A.

    1987-11-01

    The neural and behavioral effects of air contaminants such as CO/sub 2/, CO, and hydrocarbons are reviewed. Each contaminant or contaminant class is reviewed separately and then an attempt is made to estimate effects of combinations of contaminants. The effects are reviewed for both normobaric and hyperbaric conditions. Rough dose-effects curves were constructed from data found in the literature.

  16. Formaldehyde: a candidate toxic air contaminant. Final report

    SciTech Connect

    Frye, B.; Parker, T.

    1988-03-01

    Formaldehyde (HCHO) is a gas widely used in adhesives and resins, textiles, embalming fluids, fungicides, air fresheners, and cosmetics. It is directly emitted into the ambient outdoor air from vehicular and stationary sources, and is also produced in the atmosphere from other substances by photochemical smog processes. The International Agency for Research on Cancer (IARC) has determined that there is sufficient evidence for carcinogenicity of formaldehyde to animals, and limited evidence for carcinogenicity to humans. EPA classifies formaldehyde as a probable human carcinogen with a one in a million risk concentration of 0.08 ppb.

  17. Remediation alternatives for low-level herbicide contaminated groundwater

    SciTech Connect

    Conger, R.M.

    1995-10-01

    In early 1995, an evaluation of alternatives for remediation of a shallow groundwater plume containing low-levels of an organic herbicide was conducted at BASF Corporation, a petrochemical facility located in Ascension Parish, Louisiana. The contaminated site is located on an undeveloped portion of property within 1/4 mile of the east bank of the Mississippi River near the community of Geismar. Environmental assessment data indicated that about two acres of the thirty acre site had been contaminated from past waste management practices with the herbicide bentazon. Shallow soils and groundwater between 5 to 15 feet in depth were affected. Maximum concentrations of bentazon in groundwater were less than seven parts per million. To identify potentially feasible remediation alternatives, the environmental assessment data, available research, and cost effectiveness were reviewed. After consideration of a preliminary list of alternatives, only two potentially feasible alternatives could be identified. Groundwater pumping, the most commonly used remediation alternative, followed by carbon adsorption treatment was identified as was a new innovative alternative known as vegetative transpiration. This alternative relies on the natural transpiration processes of vegetation to bioremediate organic contaminants. Advantages identified during screening suggest that the transpiration method could be the best remediation alternative to address both economic and environmental factors. An experiment to test critical factors of the vegetatived transpiration alternative with bentazon was recommended before a final decision on feasibility can be made.

  18. Removing volatile contaminants from the unsaturated zone by inducing advective air-phase transport

    USGS Publications Warehouse

    Baehr, A.L.; Hoag, G.E.; Marley, M.C.

    1989-01-01

    Organic liquids inadvertently spilled and then distributed in the unsaturated zone can pose a long-term threat to ground water. Many of these substances have significant volatility, and thereby establish a premise for contaminant removal from the unsaturated zone by inducing advective air-phase transport with wells screened in the unsaturated zone. In order to focus attention on the rates of mass transfer from liquid to vapour phases, sand columns were partially saturated with gasoline and vented under steady air-flow conditions. The ability of an equilibrium-based transport model to predict the hydrocarbon vapor flux from the columns implies an efficient rate of local phase transfer for reasonably high air-phase velocities. Thus the success of venting remediations will depend primarily on the ability to induce an air-flow field in a heterogeneous unsaturated zone that will intersect the distributed contaminant. To analyze this aspect of the technique, a mathematical model was developed to predict radially symmetric air flow induced by venting from a single well. This model allows for in-situ determinations of air-phase permeability, which is the fundamental design parameter, and for the analysis of the limitations of a single well design. A successful application of the technique at a site once contaminated by gasoline supports the optimism derived from the experimental and modeliing phases of this study, and illustrates the well construction and field methods used to document the volatile contaminant recovery. ?? 1989.

  19. INTEGRATION OF PHOTOCATALYTIC OXIDATION WITH AIR STRIPPING OF CONTAMINATED AQUIFERS

    EPA Science Inventory

    Bench scale laboratory studies and pilot scale studies in a simulated field-test situation were performed to evaluate the integration of gas-solid ultaviolet (UV) photocatalytic oxidation (PCO) downstream if an air stripper unit as a technology for cost-effectively treating water...

  20. Effects of walk-by and sash movement on contaminant leakage of air curtain-isolated fume hood.

    PubMed

    Huang, Rong Fung; Chen, Hong Da; Hung, Chien-Hsiung

    2007-12-01

    The effects of the walk-by motion and sash movement on the containment leakage of an air curtain-isolated fume hood were evaluated and compared with the results of a corresponding conventional fume hood. The air curtain was generated by a narrow planar jet issued from the double-layered sash and a suction slot-flow arranged on the floor of the hood just behind the doorsill. The conventional fume hood used for comparison had the major dimensions identical to the air-curtain hood. SF tracer-gas concentrations were released and measured following the prEN 14175-3:2003 protocol to examine the contaminant leakage levels. Experimental results showed that operating the air-curtain hood at the suction velocity above about 6 m/s and jet velocity about 1 m/s could provide drastically high containment performance when compared with the corresponding conventional fume hood operated at the face velocity of 0.5 m/s. The total air flow required for the air-curtain hood operated at 6 m/s suction velocity and 1 m/s jet velocity was about 20% less than that exhausted by the conventional fume hood. If the suction velocity of the air-curtain hood was increased above 8 m/s, the containment leakage during dynamic motions could be reduced to ignorable level (about 10(3) ppm). PMID:18212476

  1. Estimation of Potential Population Level Effects of Contaminants on Wildlife

    SciTech Connect

    Loar, J.M.

    2001-06-11

    The objective of this project is to provide DOE with improved methods to assess risks from contaminants to wildlife populations. The current approach for wildlife risk assessment consists of comparison of contaminant exposure estimates for individual animals to literature-derived toxicity test endpoints. These test endpoints are assumed to estimate thresholds for population-level effects. Moreover, species sensitivities to contaminants is one of several criteria to be considered when selecting assessment endpoints (EPA 1997 and 1998), yet data on the sensitivities of many birds and mammals are lacking. The uncertainties associated with this approach are considerable. First, because toxicity data are not available for most potential wildlife endpoint species, extrapolation of toxicity data from test species to the species of interest is required. There is no consensus on the most appropriate extrapolation method. Second, toxicity data are represented as statistical measures (e.g., NOAEL s or LOAELs) that provide no information on the nature or magnitude of effects. The level of effect is an artifact of the replication and dosing regime employed, and does not indicate how effects might increase with increasing exposure. Consequently, slight exceedance of a LOAEL is not distinguished from greatly exceeding it. Third, the relationship of toxic effects on individuals to effects on populations is poorly estimated by existing methods. It is assumed that if the exposure of individuals exceeds levels associated with impaired reproduction, then population level effects are likely. Uncertainty associated with this assumption is large because depending on the reproductive strategy of a given species, comparable levels of reproductive impairment may result in dramatically different population-level responses. This project included several tasks to address these problems: (1) investigation of the validity of the current allometric scaling approach for interspecies extrapolation

  2. OPERATIONAL LIMITATIONS FOR DEMOLITION OF A HIGHLY ALPHA CONTAMINATED BUILDING MODLES VERSUS MEASURED AIR & SURFACE ACTIVITY CONCENTRATIONS

    SciTech Connect

    LLOYD, E.R.

    2006-11-02

    The demolition of a facility historically used for processing and handling transuranic materials is considered. Residual alpha emitting radionuclide contamination poses an exposure hazard if released to the local environment during the demolition. The process of planning for the demolition of this highly alpha contaminated building, 232-Z, included a predemolition modeling analysis of potential exposures. Estimated emission rates were used as input to an air dispersion model to estimate frequencies of occurrence of peak air and surface exposures. Postdemolition modeling was also conducted, based on the actual demolition schedule and conditions. The modeling results indicated that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. During the demolition of 232-Z, airborne radiation and surface contamination were monitored. The resultant non-detect monitoring results indicate a significant level of conservatism in the modeled results. This comparison supports the use of more realistic assumption in the estimating emission rates. The resultant reduction in modeled levels of potential exposures has significant implications in terms of the projected costs of demolition of such structures.

  3. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1992-03-01

    An environmental investigation of ground water conditions has been undertaken at Wright-Patterson Air Force Base (WPAFB), Ohio to obtain data to assist in the evaluation of a potential removal action to prevent, to the extent practicable, migration of the contaminated ground water across Base boundaries. Field investigations were limited to the central section of the southwestern boundary of Area C and the Springfield Pike boundary of Area B. Further, the study was limited to a maximum depth of 150 feet below grade. Three primary activities of the field investigation were: (1) installation of 22 monitoring wells, (2) collection and analysis of ground water from 71 locations, (3) measurement of ground water elevations at 69 locations. Volatile organic compounds including trichloroethylene, perchloroethylene, and/or vinyl chloride were detected in concentrations exceeding Maximum Contaminant Levels (MCL) at three locations within the Area C investigation area. Ground water at the Springfield Pike boundary of Area B occurs in two primary units, separated by a thicker-than-expected clay layers. One well within Area B was determined to exceed the MCL for trichloroethylene.

  4. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1991-10-01

    In April 1990 Wright-Patterson Air Force Base (WPAFB) initiated an investigation to evaluate a potential CERCLA removal action to prevent, to the extent practicable, the migration of ground-water contamination in the Mad River Valley Aquifer within and across WPAFB boundaries. The action will be based on a Focused Feasibility Study with an Action Memorandum serving as a decision document that is subject to approval by the Ohio Environmental Protection Agency. The first phase (Phase 1) of this effort involves an investigation of ground-water contamination migrating across the southwest boundary of Area C and across Springfield Pike adjacent to Area B. Task 4 of Phase 1 is a field investigation to collect sufficient additional information to evaluate removal alternatives. The field investigation will provide information in the following specific areas of study: water-level data which will be used to permit calibration of the ground-water flow model to a unique time in history; and ground-water quality data which will be used to characterize the current chemical conditions of ground water.

  5. Estimated association between dwelling soil contamination and internal radiation contamination levels after the 2011 Fukushima Daiichi nuclear accident in Japan

    PubMed Central

    Tsubokura, Masaharu; Nomura, Shuhei; Sakaihara, Kikugoro; Kato, Shigeaki; Leppold, Claire; Furutani, Tomoyuki; Morita, Tomohiro; Oikawa, Tomoyoshi; Kanazawa, Yukio

    2016-01-01

    Objectives Measurement of soil contamination levels has been considered a feasible method for dose estimation of internal radiation exposure following the Chernobyl disaster by means of aggregate transfer factors; however, it is still unclear whether the estimation of internal contamination based on soil contamination levels is universally valid or incident specific. Methods To address this issue, we evaluated relationships between in vivo and soil cesium-137 (Cs-137) contamination using data on internal contamination levels among Minamisoma (10–40 km north from the Fukushima Daiichi nuclear power plant), Fukushima residents 2–3 years following the disaster, and constructed three models for statistical analysis based on continuous and categorical (equal intervals and quantiles) soil contamination levels. Results A total of 7987 people with a mean age of 55.4 years underwent screening of in vivo Cs-137 whole-body counting. A statistically significant association was noted between internal and continuous Cs-137 soil contamination levels (model 1, p value <0.001), although the association was slight (relative risk (RR): 1.03 per 10 kBq/m2 increase in soil contamination). Analysis of categorical soil contamination levels showed statistical (but not clinical) significance only in relatively higher soil contamination levels (model 2: Cs-137 levels above 100 kBq/m2 compared to those <25 kBq/m2, RR=1.75, p value <0.01; model 3: levels above 63 kBq/m2 compared to those <11 kBq/m2, RR=1.45, p value <0.05). Conclusions Low levels of internal and soil contamination were not associated, and only loose/small associations were observed in areas with slightly higher levels of soil contamination in Fukushima, representing a clear difference from the strong associations found in post-disaster Chernobyl. These results indicate that soil contamination levels generally do not contribute to the internal contamination of residents in Fukushima; thus, individual

  6. Impacts of contaminant storage on indoor air quality: Model development

    SciTech Connect

    Sherman, Max H.; Hult, Erin L.

    2013-02-26

    A first-order, lumped capacitance model is used to describe the buffering of airborne chemical species by building materials and furnishings in the indoor environment. The model is applied to describe the interaction between formaldehyde in building materials and the concentration of the species in the indoor air. Storage buffering can decrease the effect of ventilation on the indoor concentration, compared to the inverse dependence of indoor concentration on the air exchange rate that is consistent with a constant emission rate source. If the exposure time of an occupant is long relative to the time scale of depletion of the compound from the storage medium, however, the total exposure will depend inversely on the air exchange rate. This lumped capacitance model is also applied to moisture buffering in the indoor environment, which occurs over much shorter depletion timescales of the order of days. This model provides a framework to interpret the impact of storage buffering on time-varying concentrations of chemical species and resulting occupant exposure. Pseudo-steady state behavior is validated using field measurements. Model behavior over longer times is consistent with formaldehyde and moisture concentration measurements in previous studies.

  7. Model for in situ air stripping of contaminated soils: Effects of hydrocarbon adsorption

    SciTech Connect

    Mehrotra, A.K.; Karan, K.; Chakma, A.

    1996-01-01

    Soil contamination due to organic compounds is a widespread problem. The contaminants enter the soil subsurface by a number of routes, such as the disposal of wastes in landfills, spills during transportation of chemicals, plant operation, and leakage from underground storage. Air stripping as a means of soil remediation has gained popularity in recent years. In this in situ process, clean air is injected into the contaminated soil zone to volatilize and strip the contaminants, which are then removed by the carrier gas. The process has been found to be effective especially for treating the vadose zone of the soil contaminated with volatile and semivolatile organics. Nitrogen adsorption/desorption experiments in this study were performed on a soil sample to establish its desorption characteristics. A field-scale model for the air stripping process has been developed to simulate the removal of semivolatile hydrocarbons. The numerical results show that the interphase contaminant transport from the sorbed to the vapor phase plays a dominant role in influencing the process effectiveness.

  8. Applying membrane technology to air stripping effluent for remediation of groundwater contaminated with volatile organic compounds

    SciTech Connect

    Brown, J.J.; Erickson, M.D.; Beskid, N.J.

    1993-12-31

    Remediation groundwater contaminated by volatile organic compounds (VOCs) requires cost- and technically-effective solutions. This paper reviews the options for VOC removal from remediation air streams, focusing on membrane separation. The basic separation science and technology, results of performance tests, and results of cost studies for membrane separation are presented. Competing technologies are discussed and compared with membrane separation. Membrane separation combined with air stripping will provide an economically and environmentally safe technology for remediation of VOC-contaminated groundwater and, as it matures, may become the preferred method. 9 refs., 6 figs., 2 tabs.

  9. Treatment options for low-level radiologically contaminated ORNL filtercake

    SciTech Connect

    Lee, Hom-Ti; Bostick, W.D.

    1996-04-01

    Water softening sludge (>4000 stored low level contaminated drums; 600 drums per year) generated by the ORNL Process Waste Treatment Plant must be treated, stabilized, and placed in safe storage/disposal. The sludge is primarily CaCO{sub 3} and is contaminated by low levels of {sup 90}Sr and {sup 137}Cs. In this study, microwave sintering and calcination were evaluated for treating the sludge. The microwave melting experiments showed promise: volume reductions were significant (3-5X), and the waste form was durable with glass additives (LiOH, fly ash). A commercial vendor using surrogate has demonstrated a melt mineralization process that yields a dense monolithic waste form with a volume reduction factor (VR) of 7.7. Calcination of the sludge at 850-900 C yielded a VR of 2.5. Compaction at 4500 psi increased the VR to 4.2, but the compressed form is not dimensionally stable. Addition of paraffin helped consolidate fines and yielded a VR of 3.5. In conclusion, microwave melting or another form of vitrification is likely to be the best method; however for immediate implementation, the calculation/compaction/waxing process is viable.

  10. [Quality of interior air: biological contaminants and their effects on health; bioaerosols and gathering techniques].

    PubMed

    Bălan, Gabriela

    2007-01-01

    Indoor Air Quality: biological contaminants and health effects; airborne organisms and sampling instruments. Biological contaminants include bacteria, molds, viruses, animal dander and cat saliva, house dust, mites, cockroaches and pollen. Symptoms of health problems caused by biological pollutants include sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fevers. Children, elderly people with breathing problems, allergies and lung diseases are particularly susceptible to disease-causing biological agents in the indoor air. It is convenient to consider microbiological samplers for collecting organisms in air as falling into several broad categories. Many popular microbiological air samplers use the principle of impaction to trap the organisms by impacting them directly on to agar. Further distinct groups are the impingers, which operate by impinging organisms into liquid. PMID:18441954

  11. Overview of the International Space Station System Level Trace Contaminant Injection Test

    NASA Technical Reports Server (NTRS)

    Tatara, James D.; Perry, Jay L.; Franks, Gerald D.

    1997-01-01

    Trace contaminant control onboard the International Space Station will be accomplished not only by the Trace Contaminant Control Subassembly but also by other Environmental Control and Life Support System subassemblies. These additional removal routes include absorption by humidity condensate in the Temperature and Humidity Control Condensing Heat Exchanger and adsorption by the Carbon Dioxide Removal Assembly. The Trace Contaminant Injection Test, which was performed at NASA's Marshall Space Flight Center, investigated the system-level removal of trace contaminants by the International Space Station Atmosphere Revitalization, and Temperature/Humidity Control Subsystems, (November-December 1997). It is a follow-on to the Integrated Atmosphere Revitalization Test conducted in 1996. An estimate for the magnitude of the assisting role provided by the Carbon Dioxide Removal Assembly and the Temperature and Humidity Control unit was obtained. In addition, data on the purity of Carbon Dioxide Removal Assembly carbon dioxide product were obtained to support Environmental Control and Life Support System Air Revitalization Subsystem loop closure.

  12. Monitoring strategy to assessment the air pollution level in Salamanca (México)

    NASA Astrophysics Data System (ADS)

    Barrón-Adame, J. M.; Cortina-Januchs, M. G.; Andina, D.; Vega-Corona, A.

    2009-04-01

    Air pollution affects not only the quality of life and the health of the urban population but also forests and agriculture. Agricultural crops can be injured when exposed to high concentrations of various air pollutants. Air pollutants can generally be classed as either local or widespread. Local pollutants are those emitted from a specific stationary source and result in a well-defined zone of vegetation injury or contamination. Most common among the local pollutants are sulphur dioxide, fluorides, ammonia and particulate matter. The paper presents an air monitoring strategy based on data fusion and Artificial Neural Networks. The main objective is to classify automatically the air pollution level as a proposal to assessment the air pollution level affecting the agriculture in Salamanca (Mexico). Salamanca is catalogued as one of the most polluted cities in Mexico. Pollutant concentrations and meteorological variables have been consider in data fusion process in order to build a Representative Pollution Vector (RPV). Meteorological variables (Wind Direction and Wind Speed) are taken as a decision factor in the air pollutant concentration level. RPV is used to train an Artificial Neural Network in order to classify new pollutant events. In the experiments, real time series gathered from the Automatic Environmental Monitoring Network (AEMN) in Salamanca have been used.

  13. 41 CFR 109-42.1102-52 - Low level contaminated personal property.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... However, recipients shall be advised where levels of radioactive contamination require specific controls... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Low level contaminated... level contaminated personal property. If monitoring of suspect personal property indicates...

  14. 41 CFR 109-42.1102-52 - Low level contaminated personal property.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... However, recipients shall be advised where levels of radioactive contamination require specific controls... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Low level contaminated... level contaminated personal property. If monitoring of suspect personal property indicates...

  15. 41 CFR 109-42.1102-52 - Low level contaminated personal property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... However, recipients shall be advised where levels of radioactive contamination require specific controls... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Low level contaminated... level contaminated personal property. If monitoring of suspect personal property indicates...

  16. 41 CFR 109-42.1102-52 - Low level contaminated personal property.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... However, recipients shall be advised where levels of radioactive contamination require specific controls... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Low level contaminated... level contaminated personal property. If monitoring of suspect personal property indicates...

  17. 41 CFR 109-42.1102-52 - Low level contaminated personal property.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... However, recipients shall be advised where levels of radioactive contamination require specific controls... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Low level contaminated... level contaminated personal property. If monitoring of suspect personal property indicates...

  18. Monitoring of raptors and their contamination levels in Norway.

    PubMed

    Gjershaug, Jan Ove; Kålås, John Atle; Nygård, Torgeir; Herzke, Dorte; Folkestad, Alv Ottar

    2008-09-01

    This article summarizes results from raptor monitoring and contamination studies in Norway of the golden eagle, gyrfalcon, white-tailed sea eagle, osprey, peregrine, and merlin. Golden eagle and gyrfalcon populations have been monitored since 1990 as part of the "Monitoring Programme for Terrestrial Ecosystems" (TOV). No long-term trend in the population size or productivity of golden eagle has been shown in any of the 5 study areas. The reproductive output of gyrfalcon is monitored in 3 areas. It is positively correlated with the populations of its main prey species, the rock ptarmigan and the willow ptarmigan. The white-tailed sea eagle population has been monitored since 1974 by the Norwegian Ornithological Society, and the population is increasing. The levels of pesticides and polychlorinated biphenyls are low in the eggs of both the golden eagle and the gyrfalcon, but elevated levels and effects on reproduction have been indicated for a coastal subpopulation of golden eagle. The pollutant levels in white-tailed sea eagle are lower than in the Baltic population of sea eagles, and shell thinning was never severe overall, but individual eggs have contained pollutant concentrations above critical levels. The levels of pollutants in the bird-eating falcons, peregrine, and merlin were higher than in other species. New emerging pollutants, like brominated diphenylethers and perfluorinated organic compounds, could be detected in all species. By incorporating available published and unpublished data, we were able to produce time trends for pollutants and shell thickness over 4 decades. PMID:18833794

  19. Assessment of the bacterial contamination of hand air dryer in washrooms.

    PubMed

    Alharbi, Sulaiman Ali; Salmen, Saleh Hussein; Chinnathambi, Arunachalam; Alharbi, Naiyf S; Zayed, M E; Al-Johny, Bassam O; Wainwright, Milton

    2016-03-01

    The present study was carried out, using standard techniques, to identify and count the bacterial contamination of hand air dryers, used in washrooms. Bacteria were isolated from the air flow, outlet nozzle of warm air dryers in fifteen air dryers used in these washrooms. Bacteria were found to be relatively numerous in the air flows. Bacterially contaminated air was found to be emitted whenever a warm air dryer was running, even when not being used for hand drying. Our investigation shows that Staphylococcus haemolyticus, Micrococcus luteus, Pseudomonas alcaligenes, Bacillus cereus and Brevundimonad diminuta/vesicularis were emitted from all of the dryers sampled, with 95% showing evidence of the presence of the potential pathogen S. haemolyticus. It is concluded that hot air dryers can deposit pathogenic bacteria onto the hands and body of users. Bacteria are distributed into the general environment whenever dryers are running and could be inhaled by users and none-users alike. The results provide an evidence base for the development and enhancement of hygienic hand drying practices. PMID:26981009

  20. [Simulation on remediation of benzene contaminated groundwater by air sparging].

    PubMed

    Fan, Yan-Ling; Jiang, Lin; Zhang, Dan; Zhong, Mao-Sheng; Jia, Xiao-Yang

    2012-11-01

    Air sparging (AS) is one of the in situ remedial technologies which are used in groundwater remediation for pollutions with volatile organic compounds (VOCs). At present, the field design of air sparging system was mainly based on experience due to the lack of field data. In order to obtain rational design parameters, the TMVOC module in the Petrasim software package, combined with field test results on a coking plant in Beijing, is used to optimize the design parameters and simulate the remediation process. The pilot test showed that the optimal injection rate was 23.2 m3 x h(-1), while the optimal radius of influence (ROI) was 5 m. The simulation results revealed that the pressure response simulated by the model matched well with the field test results, which indicated a good representation of the simulation. The optimization results indicated that the optimal injection location was at the bottom of the aquifer. Furthermore, simulated at the optimized injection location, the optimal injection rate was 20 m3 x h(-1), which was in accordance with the field test result. Besides, 3 m was the optimal ROI, less than the field test results, and the main reason was that field test reflected the flow behavior at the upper space of groundwater and unsaturated area, in which the width of flow increased rapidly, and became bigger than the actual one. With the above optimized operation parameters, in addition to the hydro-geological parameters measured on site, the model simulation result revealed that 90 days were needed to remediate the benzene from 371 000 microg x L(-1) to 1 microg x L(-1) for the site, and that the opeation model in which the injection wells were progressively turned off once the groundwater around them was "clean" was better than the one in which all the wells were kept operating throughout the remediation process.

  1. Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag Gunnar; Lindgren, Torsten; Bakke, Berit; Lundanes, Elsa; Molander, Paal

    2011-05-01

    Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max contamination of the cabin and cockpit air, was an order of magnitude higher as compared to after engine replacement (p = 0.02).

  2. Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants.

    PubMed

    Solbu, Kasper; Daae, Hanne Line; Olsen, Raymond; Thorud, Syvert; Ellingsen, Dag Gunnar; Lindgren, Torsten; Bakke, Berit; Lundanes, Elsa; Molander, Paal

    2011-05-01

    Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max contamination of the cabin and cockpit air, was an order of magnitude higher as compared to after engine replacement (p = 0.02). PMID:21399836

  3. Indoor air condensate as a novel matrix for monitoring inhalable organic contaminants.

    PubMed

    Roll, Isaac B; Halden, Rolf U; Pycke, Benny F G

    2015-05-15

    With the population of developed nations spending nearly 90% of their time indoors, indoor air quality (IAQ) is a critical indicator of human health risks from inhalation of airborne contaminants. We present a novel approach for qualitative monitoring of IAQ through the collection and analysis of indoor air condensate discharged from heat exchangers of heating, ventilation, and air conditioning (HVAC) systems. Condensate samples were collected from six suburban homes and one business in Maricopa County, Arizona, concentrated via solid-phase extraction, analyzed for 10 endocrine disrupting chemicals (EDCs) by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and screened for additional organic compounds by gas chromatography-mass spectrometry (GC-MS). All 10 EDCs were detected in at least one of the sampled buildings. More than 100 additional compounds were detected by GC-MS, of which 40 were tentatively identified using spectral database searches. Twelve compounds listed as designated chemicals for biomonitoring by the California Environmental Contaminant Biomonitoring Program were detected. Microfiltration of condensate samples prior to extraction had no discernable effect on contaminant concentration, suggesting that contaminants were freely dissolved or associated with inhalable, submicron particles. This study is the first to document the utility of HVAC condensate for the qualitative assessment of indoor air for pollutants. PMID:25706557

  4. Indoor air condensate as a novel matrix for monitoring inhalable organic contaminants.

    PubMed

    Roll, Isaac B; Halden, Rolf U; Pycke, Benny F G

    2015-05-15

    With the population of developed nations spending nearly 90% of their time indoors, indoor air quality (IAQ) is a critical indicator of human health risks from inhalation of airborne contaminants. We present a novel approach for qualitative monitoring of IAQ through the collection and analysis of indoor air condensate discharged from heat exchangers of heating, ventilation, and air conditioning (HVAC) systems. Condensate samples were collected from six suburban homes and one business in Maricopa County, Arizona, concentrated via solid-phase extraction, analyzed for 10 endocrine disrupting chemicals (EDCs) by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and screened for additional organic compounds by gas chromatography-mass spectrometry (GC-MS). All 10 EDCs were detected in at least one of the sampled buildings. More than 100 additional compounds were detected by GC-MS, of which 40 were tentatively identified using spectral database searches. Twelve compounds listed as designated chemicals for biomonitoring by the California Environmental Contaminant Biomonitoring Program were detected. Microfiltration of condensate samples prior to extraction had no discernable effect on contaminant concentration, suggesting that contaminants were freely dissolved or associated with inhalable, submicron particles. This study is the first to document the utility of HVAC condensate for the qualitative assessment of indoor air for pollutants.

  5. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1992-03-01

    This report presents information related to the sampling of ground water at the Wright-Patterson Air Force Base. It is part of an investigation into possible ground water contamination. Information concerns well drilling/construction; x-ray diffraction and sampling; soil boring logs; and chain-of-custody records.

  6. Air-Seawater Exchange of Organochlorine Pesticides along the Sediment Plume of a Large Contaminated River.

    PubMed

    Lin, Tian; Guo, Zhigang; Li, Yuanyuan; Nizzetto, Luca; Ma, Chuanliang; Chen, Yingjun

    2015-05-01

    Gaseous exchange fluxes of organochlorine pesticides (OCPs) across the air-water interface of the coastal East China Sea were determined in order to assess whether the contaminated plume of the Yangtze River could be an important regional source of OCPs to the atmosphere. Hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) were the most frequently detected OCPs in air and water. Air-water exchange was mainly characterized by net volatilization for all measured OCPs. The net gaseous exchange flux ranged 10-240 ng/(m2·day) for γ-HCH, 60-370 ng/(m2·day) for trans-CHL, 97-410 ng/(m2·day) for cis-CHL, and ∼0 (e.g., equilibrium) to 490 ng/(m2·day) for p,p'-DDE. We found that the plume of the large contaminated river can serve as a significant regional secondary atmospheric source of legacy contaminants released in the catchment. In particular, the sediment plume represented the relevant source of DDT compounds (especially p,p'-DDE) sustaining net degassing when clean air masses from the open ocean reached the plume area. In contrast, a mass balance showed that, for HCHs, contaminated river discharge (water and sediment) plumes were capable of sustaining volatilization throughout the year. These results demonstrate the inconsistencies in the fate of HCHs and DDTs in this large estuarine system with declining primary sources.

  7. Negotiating indoor air-case report on negotiation of teachers' union, school board on air contaminants.

    PubMed

    Gibson, Sarah; Levenstein, Charles

    2010-01-01

    School districts increasingly understand the need for an indoor air quality plan, but may have difficulty in producing a plan that all necessary parties will accept. This article provides a case study of how one Massachusetts school district, after experiencing environmental problems in an elementary school, worked with parents and unions to develop a comprehensive indoor air quality plan.

  8. Hazard Assessment of Chemical Air Contaminants Measured in Residences

    SciTech Connect

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

    2010-05-10

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

  9. Ozone production by a dc corona discharge in air contaminated by n-heptane

    NASA Astrophysics Data System (ADS)

    Pekárek, S.

    2008-01-01

    Beneficial purposes of ozone such as elimination of odours, harmful bacteria and mildew can be used for transportation of food, fruits and vegetables with the aim to extend their storage life. To date the main technique used for this purpose in the transportation of these commodities, e.g. by trucks, was cooling. Here a combination of cooling together with the supply of ozone into containers with these commodities is considered. For these purposes we studied the effect of air contamination by n-heptane (part of automotive fuels) and humidity on ozone production by a dc hollow needle to mesh corona discharge. We found that, for both polarities of the needle electrode, addition of n-heptane to air (a) decreases ozone production; (b) causes discharge poisoning to occur at lower current than for air; (c) does not substantially influence the current for which the ozone production reaches the maximum. Finally the maximum ozone production for the discharge in air occurs for the same current as the maximum ozone production for the discharge contaminated by n-heptane. We also found that humidity decreases ozone production from air contaminated by n-heptane irrespective of the polarity of the coronating needle electrode. This dependence is stronger for the discharge with the needle biased positively.

  10. Enhanced oxidation of air contaminants on an ultra-low density UV-accessible aerogel photocatalyst

    SciTech Connect

    Dreyer, M.; Newman, G.K.; Lobban, L.; Kersey, S.J.; Wang, R.; Harwell, J.H.

    1997-12-31

    This research developed new forms of photocatalysts that could potentially move photocatalytic degradation of air contaminants into the main stream of industrially used remediation technologies. Tests of the photocatalytic activity of the TiO{sub 2} aerogel catalysts have been carried out using both acetone and methane as the air contaminant. For comparison, the same tests were carried out on a standard (non-aerogel) anatase powder. Despite having very low crystallinity, the aerogel decontaminates the air far more effectively than an equal volume of the anatase powder which indicates that a much larger fraction of the aerogel is activated by the UV light. Experimental data were used to determine adsorption equilibrium constants for acetone, and to determine reaction rate constants assuming a Langmuir-Hinshelwood type rate expression.

  11. Use of plants to monitor contamination of air by SO2 in and around refinery.

    PubMed

    Abdul-Wahab, Sabah A; Yaghi, Basma

    2004-01-01

    The generation of SO2 from a refinery may affect the surrounding environment. Moreover, SO2 and its by-products are phytotoxic as berg. This study aims to investigate plant responses to SO2. The work has been designed with emphasis on using the plants directly in monitoring the contamination of the atmospheric air by SO2. An assessment was made of the impacts of long-term SO2 emissions from an oil refinery on plants located in nearby areas that are likely to be exposed to emission fallout. Three different plant species (Prosopis cineraria. Azadirachta indica, and Phoenix dactilifera) common to the environment of the Arabian Gulf were selected at different distances and directions from the refinery. The analysis of the sulphate contents of these plants were used as bioindicators for monitoring SO2 concentration levels in and around the refinery. The results of this study showed that the three different plant species responsed differently to SO2 in terms of their sulphate contents. Generally, all three species were found to be sensitive to SO2 exposure. Furthermore, the concentration of sulphate was found to be much higher closer to the refinery. On the basis of this study, it can be stated that even though SO2 levels were lower than the permissible limit values, the sulphate contents accumulated in the plants were likely to cause plant injury especially in the vicinity of the source. This suggests that the present environmental guidelines for SO2 may not protect sensitive plant species.

  12. Impact of extreme metal contamination at the supra-individual level in a contaminated bay ecosystem.

    PubMed

    Wu, Bin; Li, Xuegang; Song, Jinming; Hu, Limin; Shi, Xuefa

    2016-07-01

    Anthropogenic stressors impact the global environment and adversely affect the health of organisms and humans. This study was designed as an attempt to evaluate the ecological consequences of severe metal contamination at the supra-individual level based on a field investigation in Jinzhou Bay (JZB), North China in 2010. The chemical results showed high concentrations of metals in the sediment of JZB that were ~129 times greater than the local geochemical background. Furthermore, the measured metals exhibited considerably high toxicity potential indicated by sediment quality guidelines (SQGs). The mean SQGs quotients suggested the overall toxicity incidence was >70% in locations neighboring the Wulihe River mouth. Biomonitoring revealed 116 individuals distributed among a mere 6 species, 4 of which were polychaetes, at 33% of the sampling sites. Thus, few benthic organisms were present in the damaged community structures across the region, which was consistent with the extreme metal contamination. Moreover, the sediment quality assessment, in a weight of evidence framework, demonstrated that the sediment throughout the entire JZB was moderately to severely impaired, especially in the vicinity of the Wulihe River mouth. By synthesizing the present and previous chemical-biological monitoring campaigns, a possible cause-effect relationship between chemical stressors and benthic receptors was established. We also found that the hydrodynamics, sediment sources, and geochemical characteristics of the metals (in addition to the sources of the metals) were responsible for the geochemical distribution of metals in JZB. The significance of the overall finding is that the deleterious responses observed at the community level may possibly be linked to the extreme chemical stress in the sediment of JZB. PMID:26994798

  13. Contamination Revealed by Indicator Microorganism Levels during Veal Processing.

    PubMed

    Bosilevac, Joseph M; Wang, Rong; Luedtke, Brandon E; Wheeler, Tommy L; Koohmaraie, Mohammad

    2016-08-01

    During site visits of veal processors, the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS) has reported processing deficiencies that likely contribute to increased levels of veal contamination. Here, we report the results of measuring aerobic plate count bacteria (APC), Enterobacteriaceae, coliforms (CF), and Escherichia coli during eight sample collections at five veal processors to assess contamination during the harvest of bob veal and formula-fed veal before (n = 5 plants) and after (n = 3 plants) changes to interventions and processing practices. Hides of veal calves at each plant had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 6.02 to 8.07, 2.95 to 5.24, 3.28 to 5.83, and 3.08 to 5.59, respectively. Preintervention carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 3.08 to 5.22, 1.16 to 3.47, 0.21 to 3.06, and -0.07 to 3.10, respectively, before and 2.72 to 4.50, 0.99 to 2.76, 0.69 to 2.26, and 0.33 to 2.12, respectively, after changes were made to improve sanitary dressing procedures. Final veal carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 0.36 to 2.84, -0.21 to 1.59, -0.23 to 1.59, and -0.38 to 1.45 before and 0.44 to 2.64, -0.16 to 1.33, -0.42 to 1.20, and 0.48 to 1.09 after changes were made to improve carcass-directed interventions. Whereas the improved dressing procedures resulted in improved carcass cleanliness, the changes to carcass-directed interventions were less successful, and veal processors are urged to use techniques that ensure uniform and consistent delivery of antimicrobials to carcasses. Analysis of results comparing bob veal to formula-fed veal found bob veal hides, preintervention carcasses, and final carcasses to have increased (P < 0.05) APC, Enterobacteriaceae, CF, and E. coli (with the exception of hide Enterobacteriaceae; P > 0.05) relative to formula fed veal. When both veal categories were harvested at the same plant on

  14. Levels and trends of radioactive contaminants in the Greenland environment.

    PubMed

    Dahlgaard, Henning; Eriksson, Mats; Nielsen, Sven P; Joensen, Hans Pauli

    2004-09-20

    Levels of radioactive contaminants in various Greenland environments have been assessed during 1999-2001. The source of 137Cs, 90Sr and (239,240)Pu in terrestrial and fresh water environments is mainly global fallout. In addition, the Chernobyl accident gave a small contribution of 137Cs. Reindeer and lamb contain the largest observed 137Cs concentrations in the terrestrial environment--up to 80 Bq kg(-1) fresh weight have been observed in reindeer. Due to special environmental conditions, 137Cs is transferred to landlocked Arctic char with extremely high efficiency in South Greenland leading to concentrations up to 100 Bq kg(-1) fresh weight. In these cases very long ecological half-lives are seen. Concentrations of 99Tc, 137Cs and 90Sr in seawater and in marine biota decrease in the order North-East Greenland and the coastal East Greenland current > South-West Greenland > Central West Greenland and North-West Greenland > Irmiger Sea-Faroe Islands. The general large-scale oceanic circulation combined with European coastal discharges and previous contamination of the Arctic Ocean causes this. As the same tendency is seen for the persistent organic pollutants (POPs) DDT and PCB in marine biota, it is suggested that long-distance oceanic transport by coastal currents is a significant pathway also for POPs in the Greenland marine environment. The peak 99Tc discharge from Sellafield 1994-1995 has only been slightly visible in the present survey year 2000. The concentrations are expected to increase in the future, especially in East Greenland. The Bylot Sound at the Thule Airbase (Pituffik) in North-West Greenland was contaminated with plutonium and enriched uranium in a weapons accident in 1968. Biological activity has mixed accident plutonium efficiently into the new sediments resulting in continued high surface sediment concentrations three decades after the accident. Transfer of plutonium to benthic biota is low--and lower than observed in the Irish Sea. This is

  15. Contamination Revealed by Indicator Microorganism Levels during Veal Processing.

    PubMed

    Bosilevac, Joseph M; Wang, Rong; Luedtke, Brandon E; Wheeler, Tommy L; Koohmaraie, Mohammad

    2016-08-01

    During site visits of veal processors, the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS) has reported processing deficiencies that likely contribute to increased levels of veal contamination. Here, we report the results of measuring aerobic plate count bacteria (APC), Enterobacteriaceae, coliforms (CF), and Escherichia coli during eight sample collections at five veal processors to assess contamination during the harvest of bob veal and formula-fed veal before (n = 5 plants) and after (n = 3 plants) changes to interventions and processing practices. Hides of veal calves at each plant had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 6.02 to 8.07, 2.95 to 5.24, 3.28 to 5.83, and 3.08 to 5.59, respectively. Preintervention carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 3.08 to 5.22, 1.16 to 3.47, 0.21 to 3.06, and -0.07 to 3.10, respectively, before and 2.72 to 4.50, 0.99 to 2.76, 0.69 to 2.26, and 0.33 to 2.12, respectively, after changes were made to improve sanitary dressing procedures. Final veal carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 0.36 to 2.84, -0.21 to 1.59, -0.23 to 1.59, and -0.38 to 1.45 before and 0.44 to 2.64, -0.16 to 1.33, -0.42 to 1.20, and 0.48 to 1.09 after changes were made to improve carcass-directed interventions. Whereas the improved dressing procedures resulted in improved carcass cleanliness, the changes to carcass-directed interventions were less successful, and veal processors are urged to use techniques that ensure uniform and consistent delivery of antimicrobials to carcasses. Analysis of results comparing bob veal to formula-fed veal found bob veal hides, preintervention carcasses, and final carcasses to have increased (P < 0.05) APC, Enterobacteriaceae, CF, and E. coli (with the exception of hide Enterobacteriaceae; P > 0.05) relative to formula fed veal. When both veal categories were harvested at the same plant on

  16. 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

  17. The organic contamination level based on the total soil mass is not a proper index of the soil contamination intensity

    USGS Publications Warehouse

    Hung, H.-W.; Daniel, Sheng G.; Lin, T.-F.; Su, Y.; Chiou, C.T.

    2009-01-01

    Concentrations of organic contaminants in common productive soils based on the total soil mass give a misleading account of actual contamination effects. This is attributed to the fact that productive soils are essentially water-saturated, with the result that the soil uptake of organic compounds occurs principally by partition into the soil organic matter (SOM). This report illustrates that the soil contamination intensity of a compound is governed by the concentration in the SOM (Com) rather than by the concentration in whole soil (Cs). Supporting data consist of the measured levels and toxicities of many pesticides in soils of widely differing SOM contents and the related levels in in-situ crops that defy explanation by the Cs values. This SOM-based index is timely needed for evaluating the contamination effects of food crops grown in different soils and for establishing a dependable priority ranking for intended remediation of numerous contamination sites.

  18. Gross Alpha Beta Radioactivity in Air Filters Measured by Ultra Low Level α/β Counter

    NASA Astrophysics Data System (ADS)

    Cfarku, Florinda; Bylyku, Elida; Deda, Antoneta; Dhoqina, Polikron; Bakiu, Erjona; Perpunja, Flamur

    2010-01-01

    Study of radioactivity in air as very important for life is done regularly using different methods in every country. As a result of nuclear reactors, atomic centrals, institutions and laboratories, which use the radioactivity substances in open or closed sources, there are a lot radioactive wastes. Mixing of these wastes after treatment with rivers and lakes waters makes very important control of radioactivity. At the other side nuclear and radiological accidents are another source of the contamination of air and water. Due to their radio toxicity, especially those of Sr90, Pu239, etc. a contamination hazard for human begins exist even at low concentration levels. Measurements of radioactivity in air have been performed in many parts of the world mostly for assessment of the doses and risk resulting from consuming air. In this study we present the results of international comparison organized by IAEA Vienna, Austria for the air filters spiked with unknown Alpha and Beta Activity. For the calibration of system we used the same filters spiked: a) with Pu-239 as alpha source; b) Sr-90 as beta source and also the blank filter. The measurements of air filter samples after calibration of the system are done with Ultra Low Level α/β Counter (MPC 9604) Protean Instrument Corporation. The high sensitivity of the system for the determination of the Gross Alpha and Beta activity makes sure detection of low values activity of air filters. Our laboratory results are: Aα = (0.19±0.01) Bq/filter and Aα (IAEA) = (0.17±0.009) Bq/filter; Aβ = (0.33±0.009) Bq/filter and Aβ (IAEA) = (0.29±0.01) Bq/filter. As it seems our results are in good agreement with reference values given by IAEA (International Atomic Energy Agency).

  19. Enhancement of the microbial community biomass and diversity during air sparging bioremediation of a soil highly contaminated with kerosene and BTEX.

    PubMed

    Kabelitz, Nadja; Machackova, Jirina; Imfeld, Gwenaël; Brennerova, Maria; Pieper, Dietmar H; Heipieper, Hermann J; Junca, Howard

    2009-03-01

    In order to obtain insights in complexity shifts taking place in natural microbial communities under strong selective pressure, soils from a former air force base in the Czech Republic, highly contaminated with jet fuel and at different stages of a bioremediation air sparging treatment, were analyzed. By tracking phospholipid fatty acids and 16S rRNA genes, a detailed monitoring of the changes in quantities and composition of the microbial communities developed at different stages of the bioventing treatment progress was performed. Depending on the length of the air sparging treatment that led to a significant reduction in the contamination level, we observed a clear shift in the soil microbial community being dominated by Pseudomonads under the harsh conditions of high aromatic contamination to a status of low aromatic concentrations, increased biomass content, and a complex composition with diverse bacterial taxonomical branches.

  20. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 1, Site assessment report

    SciTech Connect

    Not Available

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB) initiated an effort for the evaluation of potential removal of ground water contamination at the Base. This report presents a current assessment of the nature and extent of the contamination believed to be migrating across the southwestern boundary of Area C and the northern boundary of Area B based upon analysis of existing environmental data obtained from several sources. The existing data base indicates widespread, low-level contamination moving across Base boundaries at levels that pose no immediate threat to the Mad River Valley well fields. An investigation by the City of Dayton in May and June 1990, however, implies that a more identifiable plume of PCE and TCE may be crossing the southwestern boundary of Area C immediately downgradient of Landfill 5. More data is needed to delineate ground water contamination and to design and implement a suitable control system. This report concludes that although an extensive study of the boundaries in question would be the preferred approach, a limited, focused investigation and subsequent feasibility study can be accomplished with a reasonable certainty of achieving the desired outcome of this project.

  1. Two-dimensional mapping of air contaminant movement using an FTIR/computed tomography system

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Runa; Todd, Lori A.

    1995-05-01

    This paper reports on numerical studies to evaluate the use of a series of scanning open path FTIR spectrometer measurements coupled with computed tomography to create 2D maps of chemical concentrations in air. When taking open-path measurements in the field using a scanning system, depending upon the scan rate and resolution, each measurement is taken at a different point in time. Therefore, as measurements are obtained, the concentrations of the pollutants in air are changing over time and space. The computed tomography mapping system must accurately create a series of maps from air concentration profiles that are in a state of flux. This remote sensing/computed tomography system was evaluated using a series of test maps that simulated the generation and dispersion of contaminant plumes over time. Contaminant generation rate, wind speed, and wind direction were varied to create concentration profiles that changed every fifteen seconds over several hours. A computer simulation program calculated the open-path measurements using these test maps for different interferometer scan times, and a series of reconstructed maps were obtained. The reconstructed maps were compared with original test maps and were evaluated both qualitatively and quantitatively using four measures of image quality. Results of this research provide guidance as to the range of acceptable interferometer scan times that can be used to map concentrations over time using different meteorological conditions, contamination generation rates, and number of contaminant sources.

  2. [Field investigations of the air pollution level of populated territories].

    PubMed

    Vinokurov, M V

    2014-01-01

    The assessment and management of air quality of settlements is one of the priorities in the field of environmental protection. In the management of air quality the backbone factor is the methodology of the organization, performance and interpretation of data of field investigations. The present article is devoted to the analysis of the existing methodological approaches and practical aspects of their application in the organization and performance of field investigations with the aim to confirm the adequacy of the boundaries of the sanitary protection zone in the old industrial regions, hygienic evaluation of the data of field investigations of the air pollution level.

  3. Characterization of the frequency and nature of bleed air contamination events in commercial aircraft.

    PubMed

    Shehadi, M; Jones, B; Hosni, M

    2016-06-01

    Contamination of the bleed air used to pressurize and ventilate aircraft cabins is of concern due to the potential health and safety hazards for passengers and crew. Databases from the Federal Aviation Administration, NASA, and other sources were examined in detail to determine the frequency of bleed air contamination incidents. The frequency was examined on an aircraft model basis with the intent of identifying aircraft make and models with elevated frequencies of contamination events. The reported results herein may help investigators to focus future studies of bleed air contamination incidents on smaller number of aircrafts. Incident frequency was normalized by the number of aircraft, number of flights, and flight hours for each model to account for the large variations in the number of aircraft of different models. The focus of the study was on aircraft models that are currently in service and are used by major airlines in the United States. Incidents examined in this study include those related to smoke, oil odors, fumes, and any symptom that might be related to exposure to such contamination, reported by crew members, between 2007 and 2012, for US-based carriers for domestic flights and all international flights that either originated or terminated in the US. In addition to the reported frequency of incidents for different aircraft models, the analysis attempted to identify propulsion engines and auxiliary power units associated with aircrafts that had higher frequencies of incidents. While substantial variations were found in frequency of incidents, it was found that the contamination events were widely distributed across nearly all common models of aircraft.

  4. Contamination of the turbine air chamber: a risk of cross infection.

    PubMed

    Checchi, L; Montebugnoli, L; Samaritani, S

    1998-08-01

    In the present work, we evaluated (a) the influx of contaminating fluid into the air chamber when a high-speed turbine stops rotating, (b) the significance of a series of variables (type of handpiece and dental unit, shape of the bur, number of stops set on the turbine) which condition it, and (c) the time required to expel the contaminating fluid from the turbine head. Results showed that contamination takes place every time the turbine stops rotating with the bur in contact with an external fluid. The main variable affecting the influx of contaminating fluid into the air chamber of the turbine head was represented by the shape of the bur (F=54.9; p<0.01). Another significant variable was the type of handpiece and dental unit (F=7.3; p<0.01). The number of stops set on the turbine was irrelevant (F=0.03; p=n.s.). The expulsion of the contaminant from the turbine head showed 2 different exponential rates: a very rapid-elimination phase within 30 s and a slow-elimination phase between 60 and 300 s. In order to remove over 99% of the contaminant from the air chamber, a turbine had to run for more than 4-7 min depending on the type of the handpiece. In conclusion, data from the present study suggest that a significant cross-infection potential exists with high-speed handpieces whenever they are only externally scrubbed and disinfected so the internal cleaning and sterilization between patients is mandatory. The practice of flushing by running the turbines between patients should be discouraged. PMID:9722263

  5. Characterization of the frequency and nature of bleed air contamination events in commercial aircraft.

    PubMed

    Shehadi, M; Jones, B; Hosni, M

    2016-06-01

    Contamination of the bleed air used to pressurize and ventilate aircraft cabins is of concern due to the potential health and safety hazards for passengers and crew. Databases from the Federal Aviation Administration, NASA, and other sources were examined in detail to determine the frequency of bleed air contamination incidents. The frequency was examined on an aircraft model basis with the intent of identifying aircraft make and models with elevated frequencies of contamination events. The reported results herein may help investigators to focus future studies of bleed air contamination incidents on smaller number of aircrafts. Incident frequency was normalized by the number of aircraft, number of flights, and flight hours for each model to account for the large variations in the number of aircraft of different models. The focus of the study was on aircraft models that are currently in service and are used by major airlines in the United States. Incidents examined in this study include those related to smoke, oil odors, fumes, and any symptom that might be related to exposure to such contamination, reported by crew members, between 2007 and 2012, for US-based carriers for domestic flights and all international flights that either originated or terminated in the US. In addition to the reported frequency of incidents for different aircraft models, the analysis attempted to identify propulsion engines and auxiliary power units associated with aircrafts that had higher frequencies of incidents. While substantial variations were found in frequency of incidents, it was found that the contamination events were widely distributed across nearly all common models of aircraft. PMID:25864418

  6. Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

    SciTech Connect

    Cunningham, M.E.; Thomas, L.E.

    1995-06-01

    The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

  7. Microbial Air Quality and Bacterial Surface Contamination in Ambulances During Patient Services

    PubMed Central

    Luksamijarulkul, Pipat; Pipitsangjan, Sirikun

    2015-01-01

    Objectives We sought to assess microbial air quality and bacterial surface contamination on medical instruments and the surrounding areas among 30 ambulance runs during service. Methods We performed a cross-sectional study of 106 air samples collected from 30 ambulances before patient services and 212 air samples collected during patient services to assess the bacterial and fungal counts at the two time points. Additionally, 226 surface swab samples were collected from medical instrument surfaces and the surrounding areas before and after ambulance runs. Groups or genus of isolated bacteria and fungi were preliminarily identified by Gram’s stain and lactophenol cotton blue. Data were analyzed using descriptive statistics, t-test, and Pearson’s correlation coefficient with a p-value of less than 0.050 considered significant. Results The mean and standard deviation of bacterial and fungal counts at the start of ambulance runs were 318±485cfu/m3 and 522±581cfu/m3, respectively. Bacterial counts during patient services were 468±607cfu/m3 and fungal counts were 656±612cfu/m3. Mean bacterial and fungal counts during patient services were significantly higher than those at the start of ambulance runs, p=0.005 and p=0.030, respectively. For surface contamination, the overall bacterial counts before and after patient services were 0.8±0.7cfu/cm2 and 1.3±1.1cfu/cm2, respectively (p<0.001). The predominant isolated bacteria and fungi were Staphylococcus spp. and Aspergillus spp., respectively. Additionally, there was a significantly positive correlation between bacterial (r=0.3, p<0.010) and fungal counts (r=0.2, p=0.020) in air samples and bacterial counts on medical instruments and allocated areas. Conclusions This study revealed high microbial contamination (bacterial and fungal) in ambulance air during services and higher bacterial contamination on medical instrument surfaces and allocated areas after ambulance services compared to the start of ambulance runs

  8. Microlith-Based Catalytic Reactor for Air Quality and Trace Contaminant Control Applications

    NASA Technical Reports Server (NTRS)

    Vilekar, Saurabh; Hawley, Kyle; Junaedi, Christian; Crowder, Bruce; Prada, Julian; Mastanduno, Richard; Perry, Jay L.; Kayatin, Matthew J.

    2015-01-01

    Traditionally, gaseous compounds such as methane, carbon monoxide, and trace contaminants have posed challenges for maintaining clean air in enclosed spaces such as crewed spacecraft cabins as they are hazardous to humans and are often difficult to remove by conventional adsorption technology. Catalytic oxidizers have provided a reliable and robust means of disposing of even trace levels of these compounds by converting them into carbon dioxide and water. Precision Combustion, Inc. (PCI) and NASA - Marshall (MSFC) have been developing, characterizing, and optimizing high temperature catalytic oxidizers (HTCO) based on PCI's patented Microlith® technology to meet the requirements of future extended human spaceflight explorations. Current efforts have focused on integrating the HTCO unit with a compact, simple recuperative heat exchanger to reduce the overall system size and weight while also reducing its energy requirements. Previous efforts relied on external heat exchangers to recover the waste heat and recycle it to the oxidizer to minimize the system's power requirements; however, these units contribute weight and volume burdens to the overall system. They also result in excess heat loss due to the separation of the HTCO and the heat recuperator, resulting in lower overall efficiency. Improvements in the recuperative efficiency and close coupling of HTCO and heat recuperator lead to reductions in system energy requirements and startup time. Results from testing HTCO units integrated with heat recuperators at a variety of scales for cabin air quality control and heat melt compactor applications are reported and their benefits over previous iterations of the HTCO and heat recuperator assembly are quantified in this paper.

  9. Measurement of 16 volatile organic compounds in restaurant air contaminated with environmental tobacco smoke.

    PubMed

    Vainiotalo, S; Väänänen, V; Vaaranrinta, R

    2008-11-01

    Tobacco smoke-related air pollutant levels were studied in ten Finnish restaurants. Markers of tobacco smoke were measured together with other compounds typical of tobacco smoke and indoor air. The measurements were carried out at stationary sampling points in smoking and non-smoking areas of the restaurants in 2005-2006, when at least half of the service area had to be non-smoking according to the Finnish Tobacco Act. The average concentrations (geometric mean, microg/m3) of the 16 airborne contaminants measured in the smoking area were: nicotine 18.1; toluene 10.6; isoprene 10.2; m,p-xylene 5.0; limonene 4.8; benzene 3.3; furfuryl aldehyde 3.2; 1,3-butadiene 2.7; 3-ethenylpyridine (3-EP) 2.5; phenol 2.1; ethyl benzene 1.7; pyridine 1.6; o-xylene 1.5; 3-picoline 1.4; styrene 1.2; and naphthalene 0.45. A good correlation (r=0.90-0.99, p<0.001) was obtained between tobacco-specific markers (3-EP and nicotine) and 1,3-butadiene, isoprene, pyridine, furfuryl aldehyde, 3-picoline, phenol, and styrene. A poor or no correlation (r=0.19-0.60) was obtained between 3-EP or nicotine and the rest of the compounds. The average concentrations of all compounds were significantly lower in the non-smoking area than in the smoking area (p<0.05). In the non-smoking area, the average concentration of 3-EP was 0.35 microg/m3 and that of nicotine 1.6 microg/m3. In three restaurants, the area design and ventilation were effective: the average level of 3-EP in the non-smoking section was <3% from that in the smoking section. In the other restaurants, tobacco smoke was spreading more freely and the corresponding value was 14-76%. A sensitive method was applied for the measurement of airborne 1,3-butadiene. The air samples were collected into Carbopack X adsorption tubes and analysed by thermal desorption/gas chromatography/mass selective detection. The precision of the method was 4.2% (at 100 ng/sample) and the limit of quantification 0.02 microg/m3.

  10. Characterization of air contaminants formed by the interaction of lava and sea water.

    PubMed

    Kullman, G J; Jones, W G; Cornwell, R J; Parker, J E

    1994-05-01

    We made environmental measurements to characterize contaminants generated when basaltic lava from Hawaii's Kilauea volcano enters sea water. This interaction of lava with sea water produces large clouds of mist (LAZE). Island winds occasionally directed the LAZE toward the adjacent village of Kalapana and the Hawaii Volcanos National Park, creating health concerns. Environmental samples were taken to measure airborne concentrations of respirable dust, crystalline silica and other mineral compounds, fibers, trace metals, inorganic acids, and organic and inorganic gases. The LAZE contained quantifiable concentrations of hydrochloric acid (HCl) and hydrofluoric acid (HF); HCl was predominant. HCl and HF concentrations were highest in dense plumes of LAZE near the sea. The HCl concentration at this sampling location averaged 7.1 ppm; this exceeds the current occupational exposure ceiling of 5 ppm. HF was detected in nearly half the samples, but all concentrations were <1 ppm Sulfur dioxide was detected in one of four short-term indicator tube samples at approximately 1.5 ppm. Airborne particulates were composed largely of chloride salts (predominantly sodium chloride). Crystalline silica concentrations were below detectable limits, less than approximately 0.03 mg/m3 of air. Settled dust samples showed a predominance of glass flakes and glass fibers. Airborne fibers were detected at quantifiable levels in 1 of 11 samples. These fibers were composed largely of hydrated calcium sulfate. These findings suggest that individuals should avoid concentrated plumes of LAZE near its origin to prevent over exposure to inorganic acids, specifically HCl.

  11. Characterization of air contaminants formed by the interaction of lava and sea water.

    PubMed

    Kullman, G J; Jones, W G; Cornwell, R J; Parker, J E

    1994-05-01

    We made environmental measurements to characterize contaminants generated when basaltic lava from Hawaii's Kilauea volcano enters sea water. This interaction of lava with sea water produces large clouds of mist (LAZE). Island winds occasionally directed the LAZE toward the adjacent village of Kalapana and the Hawaii Volcanos National Park, creating health concerns. Environmental samples were taken to measure airborne concentrations of respirable dust, crystalline silica and other mineral compounds, fibers, trace metals, inorganic acids, and organic and inorganic gases. The LAZE contained quantifiable concentrations of hydrochloric acid (HCl) and hydrofluoric acid (HF); HCl was predominant. HCl and HF concentrations were highest in dense plumes of LAZE near the sea. The HCl concentration at this sampling location averaged 7.1 ppm; this exceeds the current occupational exposure ceiling of 5 ppm. HF was detected in nearly half the samples, but all concentrations were <1 ppm Sulfur dioxide was detected in one of four short-term indicator tube samples at approximately 1.5 ppm. Airborne particulates were composed largely of chloride salts (predominantly sodium chloride). Crystalline silica concentrations were below detectable limits, less than approximately 0.03 mg/m3 of air. Settled dust samples showed a predominance of glass flakes and glass fibers. Airborne fibers were detected at quantifiable levels in 1 of 11 samples. These fibers were composed largely of hydrated calcium sulfate. These findings suggest that individuals should avoid concentrated plumes of LAZE near its origin to prevent over exposure to inorganic acids, specifically HCl. PMID:8593853

  12. Contamination level of alginate impressions arriving at a dental laboratory.

    PubMed

    Sofou, A; Larsen, T; Fiehn, N-E; Owall, B

    2002-09-01

    The contamination level of alginate impressions delivered to a large dental laboratory in Sweden was determined. One hundred and seven consecutive alginate impressions were included during 7 days. Samples were taken and transferred into sterile physiological saline and analysed microbiologically for colony-forming units (cfu) as well as nonhemolytic, alpha-hemolytic, and beta-hemolytic colonies. After sampling, the clinics were contacted and asked to fill in simple questionnaires about their routines of disinfecting impressions. The questionnaire study revealed that about half of the clinics had some kind of disinfection routine, while the others rinsed in running water only. Seventy-two percent of the impressions yielded growth of bacteria, with a median number of 1.3x10(2) cfu. Thirteen per cent of the samples yielded >10(3) cfu, with a maximum number of 3.4x10(4) cfu. The majority of isolates were non- and alpha-hemolytic bacteria. Growth was recorded in 61.3% of disinfected impressions, and the numbers of bacteria in disinfected and nondisinfected impressions were similar. These findings raise the question of whether impressions need to be disinfected or if proper handling and hygienic procedures are sufficient to block the possible route of infection. PMID:12271349

  13. Contamination level of alginate impressions arriving at a dental laboratory.

    PubMed

    Sofou, A; Larsen, T; Fiehn, N-E; Owall, B

    2002-09-01

    The contamination level of alginate impressions delivered to a large dental laboratory in Sweden was determined. One hundred and seven consecutive alginate impressions were included during 7 days. Samples were taken and transferred into sterile physiological saline and analysed microbiologically for colony-forming units (cfu) as well as nonhemolytic, alpha-hemolytic, and beta-hemolytic colonies. After sampling, the clinics were contacted and asked to fill in simple questionnaires about their routines of disinfecting impressions. The questionnaire study revealed that about half of the clinics had some kind of disinfection routine, while the others rinsed in running water only. Seventy-two percent of the impressions yielded growth of bacteria, with a median number of 1.3x10(2) cfu. Thirteen per cent of the samples yielded >10(3) cfu, with a maximum number of 3.4x10(4) cfu. The majority of isolates were non- and alpha-hemolytic bacteria. Growth was recorded in 61.3% of disinfected impressions, and the numbers of bacteria in disinfected and nondisinfected impressions were similar. These findings raise the question of whether impressions need to be disinfected or if proper handling and hygienic procedures are sufficient to block the possible route of infection.

  14. Microbial contamination detection at low levels by [125]I radiolabeling

    NASA Astrophysics Data System (ADS)

    Summers, David; Karouia, Fathi

    Contamination of mission spacecraft is an ongoing issue. A broad diversity of microorganisms have been detected in clean rooms where spacecraft are assembled. Some of which, depicted as oligotroph, are of special regard, as they are capable of colonizing inorganic surfaces like metal, and have been shown to be a concern for forward contamination of pristine celestial bodies. Currently, the NASA standard assay is the only approved assay intended for the enumeration of spores and heterotrophic microbial populations. However, culture-based microbial detection methods underestimate the viable microbial population. More recently, adenosine triphosphate (ATP) bioluminescence and limulus amebocyte lysate (LAL) assays, which employ measure-ments of selected metabolic products as a proxy of biomass, have been used successfully to circumvent the necessity of the growth of microorganisms in order to estimate the biodurdens associated with spacecraft assembly facility. However, these methods have limitation in the amount of cells that can be detected, i.e., 103 cells, and the type of microorganisms respec-tively. This work seeks to develop a new highly sensitive method for the determination of bioburdens (and the detection of microorganisms and life) that is independant of the type of organism while preserving a good turn-around time for analysis for planetary protection purposes. The assay is based on the detection of the organism's protein by labeling them by radioiodination, 125 I, of aromatic rings on tyrosine amino acids residues. Radiolabeling techniques are inherently sensitive and 125 I, in particular, benefits from a 60 day half-life, providing greater activity and signal per unit number of labels. Furthermore, microorganisms can contain over 50% of protein by dry weight. Thus, just one label per protein increases the sensitivity, compared to the ATP and LAL assays, by one and three orders of magnitude by using standard detection methods and the use of multiphoton

  15. Measurements of air contaminants during the Cerro Grande fire at Los Alamos National Laboratory

    SciTech Connect

    Eberhart, Craig

    2010-08-01

    Ambient air sampling for radioactive air contaminants was continued throughout the Cerro Grande fire that burned part of Los Alamos National Laboratory. During the fire, samples were collected more frequently than normal because buildup of smoke particles on the filters was decreasing the air flow. Overall, actual sampling time was 96% of the total possible sampling time for the May 2000 samples. To evaluate potential human exposure to air contaminants, the samples were analyzed as soon as possible and for additional specific radionuclides. Analyses showed that the smoke from the fire included resuspended radon decay products that had been accumulating for many years on the vegetation and the forest floor that burned. Concentrations of plutonium, americium, and depleted uranium were also measurable, but at locations and concentrations comparable to non-fire periods. A continuous particulate matter sampler measured concentrations that exceeded the National Ambient Air Quality Standard for PM-10 (particles less than 10 micrometers in diameter). These high concentrations were caused by smoke from the fire when it was close to the sampler.

  16. Effects of low-pressure air on oxygen contamination and lithium corrosion of a tantalum alloy, T-111, at 980 and 1260 C

    NASA Technical Reports Server (NTRS)

    Gahn, R. F.

    1974-01-01

    The effects were studied of low-pressure air on contamination and corrosion in the tantalum alloy T-111/lithium system at 980 and 1260 C. Capsules of T-111 containing lithium were exposed to six vacuum levels between 1 x 10 to the 8th power and 0.0003 torr by controlled air leakage into a vacuum system. Capsules exposed at 980 C and 0.0002 torr failed from intragranular oxidation. The remainder of the capsules completed the 96-hour tests. The depth of oxygen contamination was greater at 980 C than at 1260 C. Tests made at 0.0001 and 0.00001 torr levels caused large increases in the oxygen content of the T-111. Tests at 0.000001 torr or less produced no significant contamination. No lithium corrosion of the T-111 was observed under any of the conditions.

  17. Use of inorganic dryer-salts in the determination of organic contaminants in air

    SciTech Connect

    Simonov, V.A.

    1985-09-01

    This paper presents results of a study of the adsorptive activity of a number of inorganic salts relative to water vapor and to organic vapors in air under the dynamic conditions which are uses in the indicator tube method. Data are also given on the properties of dryer salts having a surface modified with glycerin. It is shown that lithium chloride on porcelain and potassium carbonate having a surface modified with glycerin can be used to dry air in determining contaminants of nonpolar and polar organic substances in it. Anhydrone on porcelain, calcium chloride, and potassium carbonate absorb some substances which are being determined and therefore are less suitable.

  18. (Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1991-10-01

    This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

  19. Applicability of the environmental relative moldiness index for quantification of residential mold contamination in an air pollution health effects study.

    PubMed

    Kamal, Ali; Burke, Janet; Vesper, Stephen; Batterman, Stuart; Vette, Alan; Godwin, Christopher; Chavez-Camarena, Marina; Norris, Gary

    2014-01-01

    The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigated the impact of exposure to traffic-related air pollution on the respiratory health of asthmatic children in Detroit, Michigan. Since indoor mold exposure may also contribute to asthma, floor dust samples were collected in participants homes (n = 112) to assess mold contamination using the Environmental Relative Moldiness Index (ERMI). The repeatability of the ERMI over time, as well as ERMI differences between rooms and dust collection methods, was evaluated for insights into the application of the ERMI metric. ERMI values for the standard settled floor dust samples had a mean ± standard deviation of 14.5 ± 7.9, indicating high levels of mold contamination. ERMI values for samples collected from the same home 1 to 7 months apart (n = 52) were consistent and without systematic bias. ERMI values for separate bedroom and living room samples were highly correlated (r = 0.69, n = 66). Vacuum bag dust ERMI values were lower than for floor dust but correlated (r = 0.58, n = 28). These results support the use of the ERMI to evaluate residential mold exposure as a confounder in air pollution health effects studies.

  20. Applicability of the Environmental Relative Moldiness Index for Quantification of Residential Mold Contamination in an Air Pollution Health Effects Study

    PubMed Central

    Kamal, Ali; Vesper, Stephen; Batterman, Stuart; Godwin, Christopher; Chavez-Camarena, Marina; Norris, Gary

    2014-01-01

    The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigated the impact of exposure to traffic-related air pollution on the respiratory health of asthmatic children in Detroit, Michigan. Since indoor mold exposure may also contribute to asthma, floor dust samples were collected in participants homes (n = 112) to assess mold contamination using the Environmental Relative Moldiness Index (ERMI). The repeatability of the ERMI over time, as well as ERMI differences between rooms and dust collection methods, was evaluated for insights into the application of the ERMI metric. ERMI values for the standard settled floor dust samples had a mean ± standard deviation of 14.5 ± 7.9, indicating high levels of mold contamination. ERMI values for samples collected from the same home 1 to 7 months apart (n = 52) were consistent and without systematic bias. ERMI values for separate bedroom and living room samples were highly correlated (r = 0.69, n = 66). Vacuum bag dust ERMI values were lower than for floor dust but correlated (r = 0.58, n = 28). These results support the use of the ERMI to evaluate residential mold exposure as a confounder in air pollution health effects studies. PMID:25431602

  1. Plasma flame for mass purification of contaminated air with chemical and biological warfare agents

    SciTech Connect

    Uhm, Han S.; Shin, Dong H.; Hong, Yong C.

    2006-09-18

    An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22 cm diameter and 30 cm length, purifies an airflow rate of 5000 lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.

  2. Atmospheric pressure discharge plasma decomposition for gaseous air contaminants -- Trichlorotrifluoroethane and trichloroethylene

    SciTech Connect

    Oda, Tetsuji; Yamashita, Ryuichi; Takahashi, Tadashi; Masuda, Senichi

    1996-03-01

    The decomposition performance of gaseous environmental destructive contaminants in air by using atmospheric pressure discharged plasma including the surface discharge induced plasma chemical processing (SPCP) was examined. The main contaminants tested were chlorofluorocarbon (CFC-113) and trichloroethylene, typically. The discharge exciting frequency range studied was wide--50 Hz to 50 kHz. Results showed the low frequency discharge requires high voltage to inject high electric power in the gas and to decompose the contaminants. A Gas Chromatograph Mass Spectrometer was used to analyze discharge products of dense CFC-113 or trichloroethylene. Among the detected products were HCl, CClFO, and CHCl{sub 3}. Two different electrode configurations; the silent discharge (coaxial) electrode and the coil-electrode were also tested and compared to each other as a gas reactor.

  3. Microbial Contamination on Used Surgical Masks among Hospital Personnel and Microbial Air Quality in their Working Wards: A Hospital in Bangkok

    PubMed Central

    Luksamijarulkul, Pipat; Aiempradit, Natkitta; Vatanasomboon, Pisit

    2014-01-01

    Objective To assess the relationship of bacterial and fungal contamination on used surgical masks worn by the hospital personnel and microbial air quality in their working wards. Methods This is a cross-sectional study of 230 used surgical masks collected from 214 hospital personnel, and 215 indoor air samples collected from their working wards to culture for bacterial and fungal counts. This study was carried out at the hospital in Bangkok. Group or genus of isolated bacteria and fungi were preliminarily identified by Gram’s stain and lacto-phenol cotton blue. Data were analyzed using paired t-test and Pearson’s correlation coefficient at the significant level of p<0.050. Results Means and standard deviation of bacterial and fungal contamination on inside area of the used masks were 47 ± 56 and 15 ± 9 cfu/ml/piece, and on outside area were 166 ± 199 and 34 ± 18 cfu/ml/piece, respectively, p<0.001. The bacterial and fungal contamination on used masks from hospital personnel working in the male and female medical wards and out-patient department, as well as the bacterial and fungal counts of the indoor air sample collected from the same area were relatively higher than the other wards. The predominant isolated bacteria and fungi contaminated on inside and outside areas of the used masks and air samples were similar (Staphylococcus spp. and Aspergillus spp.; respectively). For its relationship, results found that bacterial and fungal counts in air samples showed significantly positive correlation with the bacterial contamination load on outside area of the used masks, r=0.16, p=0.018 and r=0.21, p=0.003, respectively. Conclusion High bacterial contamination on outside area of the used masks was demonstrated, and it showed a significant correlation with microbial air quality of working wards. PMID:25337311

  4. An air fluorescence imaging system for the detection of radiological contamination

    NASA Astrophysics Data System (ADS)

    Inrig, Elizabeth; Erhardt, Lorne; Koslowsky, Vernon; Andrews, Bob; Ing, Harry; Dick, Michael; Forget, Patrick

    2011-05-01

    On-site detection and measurement of the activity and extent of alpha (α) contamination presents a significant challenge to radiation detection personnel. Due to the short range of these particles, conventional detection techniques involve bringing a probe within a few centimetres of the suspect area. Performing a thorough survey of an area is a time consuming, painstaking, and potentially dangerous task, as personnel may be exposed to harmful radiation. Conventional detectors may have fragile Mylar windows which are highly prone to breakage. The instrumentation under development employs a novel approach: instead of detecting the radiation directly, it detects radiation-induced air fluorescence surrounding the contaminated area. Optical imaging is used to determine the spatial extent of the contamination, providing a much more rapid, accurate and robust tool for in-situ contamination measurements. A mobile, near-field, wide-angle, fast optical system has been designed and constructed to detect and image this radiation-induced air fluorescence. It incorporates large-area position-sensitive photo-multiplier tubes, UV filters, a specially constructed fast electronic shutter, and an aspherical phase mask to significantly increase the instrument's depth-of-field. First tests indicate that a 0.3 μCi α source can be detected in less than 10 seconds at a standoff distance of 1.5 meters.

  5. Investigation of remediation of soil contaminated with diesel fuel using air venting

    SciTech Connect

    Fotinich, A.; Joo, Y.; Dhir, V.K.

    1996-12-31

    Soil venting is an effective and widely used method to remediate hydrocarbonically contaminated soils. A non-isothermal model, proposed by Lingineni and Dhir (1992) to predict evaporation rates of organic contaminants in an unsaturated non-sorbing soil, was incorporated into a computer code capable of numerically analyzing multi-component diesel fuel. The program accounts for 14 major components of diesel fuel as well as for temperature variation due to evaporation of the contaminant, preheating of the venting air, and heat loss. Experiments to verify the model performance were conducted in a one-dimensional column. Temperature readings from thermocouples located in the test section were recorded during the experiment and the composition of hydrocarbons in the effluent air was also monitored. The effluent gas samples were extracted at the selected times and analyzed with the help of a gas chromatograph. The experimental temperature readings and vapor composition in the extracted samples are in general agreement with the predictions from the computer program. The results show that the diesel components are removed according to their volatility with the higher volatility components being removed first. It is also found that preheating of the venting air can significantly increase the removal rates of the components.

  6. Effectiveness of Germicidal UV Radiation for Reducing Fungal Contamination within Air-Handling Units

    PubMed Central

    Levetin, Estelle; Shaughnessy, Richard; Rogers, Christine A.; Scheir, Robert

    2001-01-01

    Levels of fungi growing on insulation within air-handling units (AHUs) in an office building and levels of airborne fungi within AHUs were measured before the use of germicidal UV light and again after 4 months of operation. The fungal levels following UV operation were significantly lower than the levels in control AHUs. PMID:11472952

  7. 40 CFR 141.53 - Maximum contaminant level goals for disinfection byproducts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant level goals for disinfection byproducts. 141.53 Section 141.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.53 Maximum contaminant level goals...

  8. 40 CFR 141.53 - Maximum contaminant level goals for disinfection byproducts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum contaminant level goals for disinfection byproducts. 141.53 Section 141.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.53 Maximum contaminant level goals...

  9. 40 CFR 141.53 - Maximum contaminant level goals for disinfection byproducts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum contaminant level goals for disinfection byproducts. 141.53 Section 141.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.53 Maximum contaminant level goals...

  10. 40 CFR 141.53 - Maximum contaminant level goals for disinfection byproducts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum contaminant level goals for disinfection byproducts. 141.53 Section 141.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.53 Maximum contaminant level goals...

  11. 40 CFR 141.53 - Maximum contaminant level goals for disinfection byproducts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum contaminant level goals for disinfection byproducts. 141.53 Section 141.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.53 Maximum contaminant level goals...

  12. Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

    NASA Technical Reports Server (NTRS)

    Condon, E. P.; Vedder, J. F.

    1984-01-01

    Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

  13. Serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in Air Force health study participants - preliminary report

    SciTech Connect

    Not Available

    1988-06-24

    In 1978, the US Air Force responded to a congressional mandate to initiate an epidemiologic study of the possible health effects of exposure to herbicides and their 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contaminants in Air Force veterans who served in the Ranch Hand defoliation operation during the Vietnam conflict. Accordingly, the Air Force conducted a nonconcurrent prospective study, the Air Force Health Study, of all 1267 members of the Ranch Hand unit and a series of matched controls. This phase of the Air Force study focused on measuring serum TCDD levels in 150 Ranch Hand veterans and 50 controls. All participants were enlisted men; the Ranch Hand veterans had been either herbicide loaders or herbicide specialists in Vietnam. The demographic and health characteristics of Ranch Hand personnel and controls were similar; however, their serum TCDD levels differed markedly.

  14. Higher fuel prices are associated with lower air pollution levels.

    PubMed

    Barnett, Adrian G; Knibbs, Luke D

    2014-05-01

    Air pollution is a persistent problem in urban areas, and traffic emissions are a major cause of poor air quality. Policies to curb pollution levels often involve raising the price of using private vehicles, for example, congestion charges. We were interested in whether higher fuel prices were associated with decreased air pollution levels. We examined an association between diesel and petrol prices and four traffic-related pollutants in Brisbane from 2010 to 2013. We used a regression model and examined pollution levels up to 16 days after the price change. Higher diesel prices were associated with statistically significant short-term reductions in carbon monoxide and nitrogen oxides. Changes in petrol prices had no impact on air pollution. Raising diesel taxes in Australia could be justified as a public health measure. As raising taxes is politically unpopular, an alternative political approach would be to remove schemes that put a downward pressure on fuel prices, such as industry subsidies and shopping vouchers that give fuel discounts.

  15. PCBs, PBDEs, and PAHs in Toronto air: spatial and seasonal trends and implications for contaminant transport.

    PubMed

    Melymuk, Lisa; Robson, Matthew; Helm, Paul A; Diamond, Miriam L

    2012-07-01

    The distributions of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Toronto, Canada and the surrounding suburban/rural area were examined. A series of temporally- and spatially-distributed air samples was collected over a 1-year period with a high-volume active air sampler at one downtown site and polyurethane foam passive air samplers at 19 sites. Passive sampler air concentrations of ΣPAHs ranged from 0.27 to 51 ng/m³. Concentrations of ΣPCBs ranged from 6.0 to 1300 pg/m³, and concentrations of ΣPBDEs ranged from 0.47 to 110 pg/m³. All compounds exhibited the highest concentrations in the urban core, and lowest concentrations in the surrounding rural areas, however the exact ratio depended on location since concentrations varied considerably within the city. Results from the application of a radial dilution model highlighted the influence of the central business district (CBD) of the city as a source of contaminants to the surrounding environment, however the radial dilution comparison also demonstrated that sources outside the CBD have a significant influence on regional contaminant concentrations. A strong relationship between temperature and partial pressure of the gas-phase PCBs, low molecular weight PBDEs and less-reactive PAHs suggested that their dominant emissions originated from temperature-controlled processes such as volatilization from local sources of PCBs, PAHs and PBDEs at warm temperatures, condensation and deposition of emissions at cold temperatures, and ventilation of indoor air with elevated concentrations. The relationship between temperature and atmospheric PAH concentrations varied along the urban-rural gradient, which suggested that in highly urbanized areas, such as downtown Toronto, temperature-related processes have a significant impact on air concentrations, whereas winter emissions from domestic heating have a greater influence in areas

  16. PCBs, PBDEs, and PAHs in Toronto air: spatial and seasonal trends and implications for contaminant transport.

    PubMed

    Melymuk, Lisa; Robson, Matthew; Helm, Paul A; Diamond, Miriam L

    2012-07-01

    The distributions of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Toronto, Canada and the surrounding suburban/rural area were examined. A series of temporally- and spatially-distributed air samples was collected over a 1-year period with a high-volume active air sampler at one downtown site and polyurethane foam passive air samplers at 19 sites. Passive sampler air concentrations of ΣPAHs ranged from 0.27 to 51 ng/m³. Concentrations of ΣPCBs ranged from 6.0 to 1300 pg/m³, and concentrations of ΣPBDEs ranged from 0.47 to 110 pg/m³. All compounds exhibited the highest concentrations in the urban core, and lowest concentrations in the surrounding rural areas, however the exact ratio depended on location since concentrations varied considerably within the city. Results from the application of a radial dilution model highlighted the influence of the central business district (CBD) of the city as a source of contaminants to the surrounding environment, however the radial dilution comparison also demonstrated that sources outside the CBD have a significant influence on regional contaminant concentrations. A strong relationship between temperature and partial pressure of the gas-phase PCBs, low molecular weight PBDEs and less-reactive PAHs suggested that their dominant emissions originated from temperature-controlled processes such as volatilization from local sources of PCBs, PAHs and PBDEs at warm temperatures, condensation and deposition of emissions at cold temperatures, and ventilation of indoor air with elevated concentrations. The relationship between temperature and atmospheric PAH concentrations varied along the urban-rural gradient, which suggested that in highly urbanized areas, such as downtown Toronto, temperature-related processes have a significant impact on air concentrations, whereas winter emissions from domestic heating have a greater influence in areas

  17. Integrated optics ring-resonator chemical sensor for detection of air contamination

    NASA Technical Reports Server (NTRS)

    Manfreda, A. M.; Homer, M. L.; Ksendzov, A.

    2004-01-01

    We report a silicon nitride-based ring resonator chemical sensor with sensing polymer coating. Its sensitivity to isopropanol in air is at least 50 ppm - well under the permissible exposure level of 400 ppm.

  18. Intregrated optics ring-resonator chemical sensor for detection of air contamination

    NASA Technical Reports Server (NTRS)

    Ksendzov, Alexander; Homer, Margie L.; Manfreda, Allison M.

    2004-01-01

    We report a silicon nitride-based ring resonator chemical sensor with sensing polymer coating. Its sensitivity to isopropanol in air is at least 50 ppm - well under the permissible exposure level of 400 ppm.

  19. Indoor air quality levels in a University Hospital in the Eastern Province of Saudi Arabia

    PubMed Central

    El-Sharkawy, Mahmoud F.; Noweir, Mohamed E. H.

    2014-01-01

    Aim of the Study: The complex hospital environment requires special attention to ensure a healthy indoor air quality (IAQ) to protect patients and healthcare workers against hospital-acquired infections and occupational diseases. Poor hospital IAQ may cause outbreaks of building-related illness such as headaches, fatigue, eye, and skin irritations, and other symptoms. The general objective for this study was to assess IAQ inside a large University hospital at Al-Khobar City in the Eastern Province of Saudi Arabia. Materials and Methods: Different locations representing areas where most activities and tasks are performed were selected as sampling points for air pollutants in the selected hospital. In addition, several factors were studied to determine those that were most likely to affect the IAQ levels. The temperature and relative percent humidity of different air pollutants were measured simultaneously at each location. Results: The outdoor levels of all air pollutant levels, except volatile organic compounds (VOCs), were higher than the indoor levels which meant that the IAQ inside healthcare facilities (HCFs) were greatly affected by outdoor sources, particularly traffic. The highest levels of total suspended particulates (TSPs) and those less than 10 microns (PM10) inside the selected hospital were found at locations that are characterized with m4ore human activity. Conclusions: Levels of particulate matter (both PM10 and TSP) were higher than the Air Quality Guidelines (AQGs). The highest concentrations of the fungal species recorded were Cladosporium and Penicillium. Education of occupants of HCF on IAQ is critical. They must be informed about the sources and effects of contaminants and the proper operation of the ventilation system. PMID:24696632

  20. BOREAS AFM-5 Level-1 Upper Air Network Data

    NASA Technical Reports Server (NTRS)

    Barr, Alan; Hrynkiw, Charmaine; Newcomer, Jeffrey A. (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing Atmospheric Environment Service (AES) aerological network, both temporally and spatially. This data set includes basic upper-air parameters collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The level-1 upper-air network data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files also are available on a CD-ROM (see document number 20010000884).

  1. Levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans in breast milk samples from three dioxin-contaminated hotspots of Vietnam.

    PubMed

    Manh, Ho Dung; Kido, Teruhiko; Tai, Pham The; Okamoto, Rie; Honma, Seijiro; Liang, Sun Xian; Anh, Le Thai; Maruzeni, Shoko; Nghi, Tran Ngoc; Nishijo, Muneko; Nakagawa, Hideaki; Nhu, Dang Duc; Van Tung, Dao; Hung, Nguyen Ngoc; Son, Le Ke

    2015-04-01

    We determined polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels in breast milk of 143 primiparae living around the three most dioxin-contaminated areas of Vietnam. The women sampled lived in the vicinity of former U.S. air bases at Bien Hoa (n=51), Phu Cat (n=23), and Da Nang (n=69), which are known as dioxin hotspots. Breast milk samples from Bien Hoa City, where residents live very close to the air base, showed high levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with 18% of the samples containing >5 pgTCDD/g lipid. However, Phu Cat residents lived far from the air base and their samples showed lower TCDD levels, with none containing >5 pgTCDD/g lipid. In Da Nang, TCDD levels in mothers from Thanh Khe (close to the air base, n=43) were significantly higher than those in mothers from Son Tra (far from the air base, n=26), but not other PCDD and PCDF (PCDD/F) congeners. Although TCDD levels in Bien Hoa were the highest among these hotspots, levels of other PCDD/F congeners as well as the geometric mean concentration of total PCDD/F level in Bien Hoa (9.3 pg toxic equivalents [TEQ]/g lipid) were significantly lower than the level observed in Phu Cat (14.1 pgTEQ/g lipid), Thanh Khe (14.3 pgTEQ/g lipid), and Son Tra (13.9 pgTEQ/g lipid). Our findings indicated that residents living close to former U.S. air bases were exposed to elevated levels of TCDD, but not of other PCDD/F congeners.

  2. Levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans in breast milk samples from three dioxin-contaminated hotspots of Vietnam.

    PubMed

    Manh, Ho Dung; Kido, Teruhiko; Tai, Pham The; Okamoto, Rie; Honma, Seijiro; Liang, Sun Xian; Anh, Le Thai; Maruzeni, Shoko; Nghi, Tran Ngoc; Nishijo, Muneko; Nakagawa, Hideaki; Nhu, Dang Duc; Van Tung, Dao; Hung, Nguyen Ngoc; Son, Le Ke

    2015-04-01

    We determined polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels in breast milk of 143 primiparae living around the three most dioxin-contaminated areas of Vietnam. The women sampled lived in the vicinity of former U.S. air bases at Bien Hoa (n=51), Phu Cat (n=23), and Da Nang (n=69), which are known as dioxin hotspots. Breast milk samples from Bien Hoa City, where residents live very close to the air base, showed high levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with 18% of the samples containing >5 pgTCDD/g lipid. However, Phu Cat residents lived far from the air base and their samples showed lower TCDD levels, with none containing >5 pgTCDD/g lipid. In Da Nang, TCDD levels in mothers from Thanh Khe (close to the air base, n=43) were significantly higher than those in mothers from Son Tra (far from the air base, n=26), but not other PCDD and PCDF (PCDD/F) congeners. Although TCDD levels in Bien Hoa were the highest among these hotspots, levels of other PCDD/F congeners as well as the geometric mean concentration of total PCDD/F level in Bien Hoa (9.3 pg toxic equivalents [TEQ]/g lipid) were significantly lower than the level observed in Phu Cat (14.1 pgTEQ/g lipid), Thanh Khe (14.3 pgTEQ/g lipid), and Son Tra (13.9 pgTEQ/g lipid). Our findings indicated that residents living close to former U.S. air bases were exposed to elevated levels of TCDD, but not of other PCDD/F congeners. PMID:25569577

  3. Gestational Diabetes and Preeclampsia in Association with Air Pollution at Levels below Current Air Quality Guidelines

    PubMed Central

    Jakobsson, Kristina; Tinnerberg, Håkan; Rignell-Hydbom, Anna; Rylander, Lars

    2013-01-01

    Background: Several studies have estimated associations between air pollution and birth outcomes, but few have evaluated potential effects on pregnancy complications. Objective: We investigated whether low-level exposure to air pollution is associated with gestational diabetes and preeclampsia. Methods: High-quality registry information on 81,110 singleton pregnancy outcomes in southern Sweden during 1999–2005 was linked to individual-level exposure estimates with high spatial resolution. Modeled exposure to nitrogen oxides (NOx), expressed as mean concentrations per trimester, and proximity to roads of different traffic densities were used as proxy indicators of exposure to combustion-related air pollution. The data were analyzed by logistic regression, with and without adjusting for potential confounders. Results: The prevalence of gestational diabetes increased with each NOx quartile, with an adjusted odds ratio (OR) of 1.69 (95% CI: 1.41, 2.03) for the highest (> 22.7 µg/m3) compared with the lowest quartile (2.5–8.9 µg/m3) of exposure during the second trimester. The adjusted OR for acquiring preeclampsia after exposure during the third trimester was 1.51 (1.32, 1.73) in the highest quartile of NOx compared with the lowest. Both outcomes were associated with high traffic density, but ORs were significant for gestational diabetes only. Conclusion: NOx exposure during pregnancy was associated with gestational diabetes and preeclampsia in an area with air pollution levels below current air quality guidelines. PMID:23563048

  4. Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

    SciTech Connect

    Kennedy, W.E. Jr.; Peloquin, R.A. )

    1990-01-01

    This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs.

  5. Numerical Assessment of Indoor Air Exposure Risk from Subsurface NAPL Contamination under Hydrologic Uncertainties

    NASA Astrophysics Data System (ADS)

    Unger, A.; Yu, S.

    2007-12-01

    Understanding the risk of indoor air exposure to residual contaminants in the subsurface following the redevelopment of contaminated land redevelopment project is a central issue at many brownfield sites. In this study, we examine various mechanisms controlling vapor phase intrusion into the indoor air of a typical residential dwelling from a NAPL source located below the water table, and consequently assess the indoor air exposure risk under multiple hydrologic uncertainties. For this purpose, a multi-phase multi-component numerical model, CompFlow Bio is used to simulate the evolution of a TCE source zone and dissolved plume in a variably saturated heterogeneous aquifer, along with the transport of dissolved TCE upwards through the capillary fringe with subsequent migration of TCE vapors in the vadose zone subject to barometric pressure fluctuations. The TCE vapors then enter the basement of the residential dwelling through a crack in the foundation slab, driven by a slight vacuum within the basement relative to the ambient atmosphere as well as the barometric pressure fluctuations. Hydrologic uncertainties affecting the indoor air concentration of TCE include the vacuum in the basement, the aperture of the crack in the foundation slab, the heterogeneous permeability field, the thickness of the capillary fringe, barometric fluctuations, recharge rates and the location of the TCE source zone. CompFlow Bio is then used to determine the future concentration of TCE into the basement as a consequence of imperfect knowledge in the various hydrologic parameters, and to evaluate the effectiveness of alternative remedial and foundation design options to minimize the exposure risk to the indoor air conditional upon the available data collected at the site. The outcome of this approach is two-fold. First, the owner of the site can reasonably evaluate the future indoor air exposure risk following the redevelopment of a formerly contaminated site following remediation

  6. Measurement and control of the air contamination generated in a medical cyclotron facility for PET radiopharmaceuticals.

    PubMed

    Calandrino, R; del Vecchio, A; Todde, S; Fazio, F

    2007-05-01

    The aim of this paper is to report the data concerning the contamination of the exhausted air from the hot cells dedicated to the large-scale synthesis of positron emission tomography (PET) radiopharmaceuticals. Two cyclotrons are currently operating in Ospedale San Raffaele for the routine production of C and F. They are linked with four radiochemistry laboratories by means of shielded radioisotope delivery lines. The above labs are dedicated both to the large scale preparation and to the research and development of PET radiopharmaceuticals. The department hosts four CT-PET scanners, which operate with a mean patient workload of 40 per day. Radiosyntheses are performed using automated modules located in 10 hot cells. The air outlets are monitored online by a 2-inch NaI(Tl) counter in a Marinelli geometry counting volume. Contamination values up to 10(5) Bq L(-1) have been measured at the hot cell exit point during the synthesis. The corresponding concentrations at the point of release in atmosphere are largely above the threshold of 1.29 Bq L(-1), defined by national regulations as the limit for free environmental release. A shielded gas storage system controlled by a dedicated, customized software program has thus been installed to prevent the potentially hazardous release of gaseous radioactive contaminants. The system has allowed us to maintain the effective dose to neighboring population groups below the limit of 10 muSv y(-1).

  7. Remediation of arsenic contaminated soil by coupling oxalate washing with subsequent ZVI/Air treatment.

    PubMed

    Cao, Menghua; Ye, Yuanyao; Chen, Jing; Lu, Xiaohua

    2016-02-01

    The application of a novel coupled process with oxalate washing and subsequent zero-valent iron (ZVI)/Air treatment for remediation of arsenic contaminated soil was investigated in the present study. Oxalate is biodegradable and widely present in the environment. With addition of 0.1 mol L(-1) oxalate under circumneutral condition, 83.7% and 52.6% of arsenic could be removed from a spiked kaolin and an actual contaminated soil respectively. Much more oxalate adsorption on the actual soil was attributed to the higher soil organic matter and clay content. Interestingly, oxalate retained in the washing effluent could act as an organic ligand to promote the oxidation efficiency of ZVI/Air at near neutral pH. Compared with the absence of oxalate, much more As(III) was oxidized. Arsenic was effectively adsorbed on iron (hydr)oxides as the consumption of oxalate and the increase of pH value. For the actual soil washing effluent, about 94.9% of total arsenic was removed after 120 min's treatment without pH adjustment. It has been demonstrated that As(V) was the dominant arsenic speciation adsorbed on iron (hydr)oxides. This study provides a promising alternative for remediation of arsenic contaminated soil in view of its low cost and environmental benign. PMID:26476769

  8. Remediation of arsenic contaminated soil by coupling oxalate washing with subsequent ZVI/Air treatment.

    PubMed

    Cao, Menghua; Ye, Yuanyao; Chen, Jing; Lu, Xiaohua

    2016-02-01

    The application of a novel coupled process with oxalate washing and subsequent zero-valent iron (ZVI)/Air treatment for remediation of arsenic contaminated soil was investigated in the present study. Oxalate is biodegradable and widely present in the environment. With addition of 0.1 mol L(-1) oxalate under circumneutral condition, 83.7% and 52.6% of arsenic could be removed from a spiked kaolin and an actual contaminated soil respectively. Much more oxalate adsorption on the actual soil was attributed to the higher soil organic matter and clay content. Interestingly, oxalate retained in the washing effluent could act as an organic ligand to promote the oxidation efficiency of ZVI/Air at near neutral pH. Compared with the absence of oxalate, much more As(III) was oxidized. Arsenic was effectively adsorbed on iron (hydr)oxides as the consumption of oxalate and the increase of pH value. For the actual soil washing effluent, about 94.9% of total arsenic was removed after 120 min's treatment without pH adjustment. It has been demonstrated that As(V) was the dominant arsenic speciation adsorbed on iron (hydr)oxides. This study provides a promising alternative for remediation of arsenic contaminated soil in view of its low cost and environmental benign.

  9. Efficient remediation of pentachlorophenol contaminated soil with tetrapolyphosphate washing and subsequent ZVI/Air treatment.

    PubMed

    Cao, Menghua; Wang, Li; Ai, Zhihui; Zhang, Lizhi

    2015-07-15

    In this study, we demonstrate that pentachlorophenol contaminated soil can be efficiently remediated with tetrapolyphosphate washing and subsequent zerovalent iron (ZVI)/Air treatment. 2 mmol L(-1) of tetrapolyphosphate could wash away 52.8% of pentachlorophenol (PCP) at pH 7.0 and 84.2% of pentachlorophenol at pH 11.0 from contaminated soil owing to the promotion effect of tetrapolyphosphate on the soil matrix dispersion and the subsequent solubilization of pentachlorophenol. More importantly, tetrapolyphosphate ions remained in the washing effluent could greatly enhance the molecular oxygen activation by ZVI to oxidize the desorbed PCP without any pH adjustment, and also avoid the competitive consumption of reactive oxygen species, as caused by the common organic surfactants in the washing effluent. Therefore, 85.1% of pentachlorophenol could be aerobically removed from the washing effluent by merely using 5 g L(-1) of ZVI. We also interestingly found that the dissolved iron ions released from the soil could enhance the oxidation of pentachlorophenol in the washing effluent, but the dissolved organic matter had the opposite effect. This study suggests the coupling tetrapolyphosphate washing and subsequent ZVI/Air treatment is an optional approach to remediate pentachlorophenol contaminated soil in view of its low cost and environmental benign.

  10. 40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... arsenic applies only to community water systems. The analyses and determination of compliance with the 0.05 milligrams per liter maximum contaminant level for arsenic use the requirements of § 141.23. (b) The maximum contaminant level for arsenic is 0.05 milligrams per liter for community water...

  11. 40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... arsenic applies only to community water systems. The analyses and determination of compliance with the 0.05 milligrams per liter maximum contaminant level for arsenic use the requirements of § 141.23. (b) The maximum contaminant level for arsenic is 0.05 milligrams per liter for community water...

  12. 40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... arsenic applies only to community water systems. The analyses and determination of compliance with the 0.05 milligrams per liter maximum contaminant level for arsenic use the requirements of § 141.23. (b) The maximum contaminant level for arsenic is 0.05 milligrams per liter for community water...

  13. 40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... arsenic applies only to community water systems. The analyses and determination of compliance with the 0.05 milligrams per liter maximum contaminant level for arsenic use the requirements of § 141.23. (b) The maximum contaminant level for arsenic is 0.05 milligrams per liter for community water...

  14. 40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... arsenic applies only to community water systems. The analyses and determination of compliance with the 0.05 milligrams per liter maximum contaminant level for arsenic use the requirements of § 141.23. (b) The maximum contaminant level for arsenic is 0.05 milligrams per liter for community water...

  15. Identification of the source of PFOS and PFOA contamination at a military air base site.

    PubMed

    Arias E, Victor A; Mallavarapu, Megharaj; Naidu, Ravi

    2015-01-01

    Although the use of perfluorooctane sulfonic acid (PFOS)/perfluorooctanoic acid (PFOA)-based aqueous fire-fighting foams (AFFF) has been banned due to their persistence, bioaccumulation and toxicity to biota, PFOS and PFOA are still present at significant levels in the environment due to their past usage. This study investigated the reasons for detection of PFOS and PFOA in an evaporation pond used to collect the wastewater arising from fire-fighting exercises at a military air base despite the replacement of PFOS/PFOA-based foam with no PFOS/PFOA-foam about 6 years ago. Concentrations in the wastewater stored in this pond ranged from 3.6 to 9.7 mg/L for PFOS and between 0.6 and 1.7 mg/L for PFOA. The hypothesis tested in a laboratory study was that PFOS and PFOA have accumulated in the sediments of the pond and can be released into the main body of the water. Concentrations detected in the sediments were 38 and 0.3 mg/g for PFOS and PFOA, respectively. These values exceed the recently reported average global values for sediments (0.2-3.8 ng/g for PFOS and from 0.1 to 0.6 ng/g for PFOA) by a factor of several thousands. PFOS and PFOA distribution coefficients were derived for the organic content of the pond sediment (1.6%). Identification of the source of contamination and knowledge of the partition between soil and aqueous phases are vital first steps in developing a sustainable remediation technology to remove the source from the site. This study clearly suggests that unless the sediment is cleaned of PFOS/PFOA, these chemicals will continue to be detected for a long period in the pond water, with potential adverse impacts on the ecosystem. PMID:25407991

  16. Characterization of air contaminants formed by the interaction of lava and sea water.

    PubMed Central

    Kullman, G J; Jones, W G; Cornwell, R J; Parker, J E

    1994-01-01

    We made environmental measurements to characterize contaminants generated when basaltic lava from Hawaii's Kilauea volcano enters sea water. This interaction of lava with sea water produces large clouds of mist (LAZE). Island winds occasionally directed the LAZE toward the adjacent village of Kalapana and the Hawaii Volcanos National Park, creating health concerns. Environmental samples were taken to measure airborne concentrations of respirable dust, crystalline silica and other mineral compounds, fibers, trace metals, inorganic acids, and organic and inorganic gases. The LAZE contained quantifiable concentrations of hydrochloric acid (HCl) and hydrofluoric acid (HF); HCl was predominant. HCl and HF concentrations were highest in dense plumes of LAZE near the sea. The HCl concentration at this sampling location averaged 7.1 ppm; this exceeds the current occupational exposure ceiling of 5 ppm. HF was detected in nearly half the samples, but all concentrations were <1 ppm Sulfur dioxide was detected in one of four short-term indicator tube samples at approximately 1.5 ppm. Airborne particulates were composed largely of chloride salts (predominantly sodium chloride). Crystalline silica concentrations were below detectable limits, less than approximately 0.03 mg/m3 of air. Settled dust samples showed a predominance of glass flakes and glass fibers. Airborne fibers were detected at quantifiable levels in 1 of 11 samples. These fibers were composed largely of hydrated calcium sulfate. These findings suggest that individuals should avoid concentrated plumes of LAZE near its origin to prevent over exposure to inorganic acids, specifically HCl. Images Figure 1. Figure 2. Figure 3. Figure 4. A Figure 4. B Figure 4. C Figure 4. D PMID:8593853

  17. Using carcinogenic potency ranking to assign air contaminants to emission classes.

    PubMed

    Schuhmacher-Wolz, Ulrike; Konietzka, Rainer; Schneider, Klaus

    2002-12-01

    Carcinogenic air contaminants are assigned to emission classes with different emission limits on the basis of their inhalation carcinogenic potency within the revised form of the German First General Administrative Regulation Pertaining to the Federal Emission Control Law (Technical Instructions on Air Quality Control-TA Luft). Accordingly, compounds with high carcinogenic potency are regulated more strictly than less potent substances. The data on carcinogenic properties are heterogeneous. Twenty-five substances or substance groups have been scrutinized and a procedure has been developed to rank these chemicals according to their carcinogenic potency. For 14 substances well-founded unit risk estimates were available to allow assignment of these air contaminants to emission classes. Unit risk estimates for bromoethane, 2-butanone oxime, and o-toluidine were derived using the ED(10)/LED(10) method based on animal studies. For several substances no qualified unit risk estimates or carcinogenicity studies were available to estimate carcinogenic potency after inhalation. Carcinogenic potency of these substances was approximated using two simple methods, T25 and CELmin.

  18. Tolerance of non-platinum group metals cathodes proton exchange membrane fuel cells to air contaminants

    NASA Astrophysics Data System (ADS)

    Reshetenko, Tatyana; Serov, Alexey; Artyushkova, Kateryna; Matanovic, Ivana; Sarah Stariha; Atanassov, Plamen

    2016-08-01

    The effects of major airborne contaminants (SO2, NO2 and CO) on the spatial performance of Fe/N/C cathode membrane electrode assemblies were studied using a segmented cell system. The injection of 2-10 ppm SO2 in air stream did not cause any performance decrease and redistribution of local currents due to the lack of stably adsorbed SO2 molecules on Fe-Nx sites, as confirmed by density functional theory (DFT) calculations. The introduction of 5-20 ppm of CO into the air stream also did not affect fuel cell performance. The exposure of Fe/N/C cathodes to 2 and 10 ppm NO2 resulted in performance losses of 30 and 70-75 mV, respectively. DFT results showed that the adsorption energies of NO2 and NO were greater than that of O2, which accounted for the observed voltage decrease and slight current redistribution. The cell performance partially recovered when the NO2 injection was stopped. The long-term operation of the fuel cells resulted in cell performance degradation. XPS analyses of Fe/N/C electrodes revealed that the performance decrease was due to catalyst degradation and ionomer oxidation. The latter was accelerated in the presence of air contaminants. The details of the spatial performance and electrochemical impedance spectroscopy results are presented and discussed.

  19. 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

  20. Tolerance of non-platinum group metals cathodes proton exchange membrane fuel cells to air contaminants

    NASA Astrophysics Data System (ADS)

    Reshetenko, Tatyana; Serov, Alexey; Artyushkova, Kateryna; Matanovic, Ivana; Sarah Stariha; Atanassov, Plamen

    2016-08-01

    The effects of major airborne contaminants (SO2, NO2 and CO) on the spatial performance of Fe/N/C cathode membrane electrode assemblies were studied using a segmented cell system. The injection of 2-10 ppm SO2 in air stream did not cause any performance decrease and redistribution of local currents due to the lack of stably adsorbed SO2 molecules on Fe-Nx sites, as confirmed by density functional theory (DFT) calculations. The introduction of 5-20 ppm of CO into the air stream also did not affect fuel cell performance. The exposure of Fe/N/C cathodes to 2 and 10 ppm NO2 resulted in performance losses of 30 and 70-75 mV, respectively. DFT results showed that the adsorption energies of NO2 and NO were greater than that of O2, which accounted for the observed voltage decrease and slight current redistribution. The cell performance partially recovered when the NO2 injection was stopped. The long-term operation of the fuel cells resulted in cell performance degradation. XPS analyses of Fe/N/C electrodes revealed that the performance decrease was due to catalyst degradation and ionomer oxidation. The latter was accelerated in the presence of air contaminants. The details of the spatial performance and electrochemical impedance spectroscopy results are presented and discussed.

  1. Cascade air-stripping system for removal of low and semi-volatile organic contaminants

    SciTech Connect

    Jang, Won.

    1989-01-01

    Many hazardous waste sites have been known to have groundwaters contaminated with low volatile, hazardous compounds such as bromoform 1,1,2,2-tetrachloroethane, 1,2-dibromo-3-chloropropane (DBCP), napthalene, and polychlorinated biphenyls (PCBs). In addition, a large number of public water supplies have been reported to have taste and odor problems in drinking water, which are attributed primarily to naturally occurring compounds, such as 2-methylisoborneol (MIB), geosmin, etc. These classes of compounds have very low Henry's Constant, H{sub c}, in the range of 1 to 50 atm. Air-stripping in countercurrent packed towers is a well accepted treatment process for removing volatile organic chemicals (VOCs) from water. The USEPA has identified packed countercurrent air-stripping as not only the least-cost, but also one of the best available technologies for the removal of VOCs. However, the economic viability of this process is limited to volatile compounds of H{sub c} value greater than SO atm. A novel modification of the conventional countercurrent air-stripping process, introduced as cascade air-stripping was proposed for cost effective removal of these classes of compounds from water and at hazardous waste spill-sites. The main objectives of this study were to demonstrate the concept of cascade air-stripping; to compare cascade air-stripping with conventional air-stripping under identical conditions; and to verify the hypothesis that the cascade system is superior to the conventional system at the pilot and prototype scales. Results of the pilot and prototype study showed that the cascade airstrip ping system was a viable and economical approach to remove low and semi-volatile organic compounds from water. The cascade system consistently showed higher removals than the conventional system for both pilot and prototype scale study.

  2. Assessment of ground-water contamination at Wurtsmith Air Force Base, Michigan, 1982-85

    USGS Publications Warehouse

    Cummings, T.R.; Twenter, F.R.

    1986-01-01

    Continued study of ground-water contamination at Wurtsmith Air Force Base, Michigan, defined the movement and distribution of volatile organic compounds in the glacial sand and gravel aquifer at known sites of contamination, and has defined new plumes at two other sites. The Arrow Street purge system, installed in 1982 to remove contaminants from the Building 43 plume, has lowered concentrations of trichloroethylene in ground water in the central part of the most contaminated area from a range of 1,000 to 2,000 micrograms per liter to about 200 micrograms per liter. Trichloroethylene is not escaping off-Base from this area. In the southern part of the Base a plume containing principally trichloroethylene and dichloroethylene has been delineated along Mission Drive. Maximum concentrations observed were 5,290 micrograms per liter of trichloroethylene and 1,480 micrograms per liter of dichloroethylene. Hydrologically suitable sites for purge wells are identified in the southern part of the plume using a new ground-water flow model of the Base. A benzene plume near the bulk-fuel storage area, delineated in earlier work, lias shifted to a more northerly direction under influence of the Arrow Street purge system. Sites initially identified for purging the benzene plume have been repositioned because of the change in contaminant movement. JP-4 fuel was found to be accumulating in wells near the bulk-fuel storage area, largely in response to seasonal fluctuations in the water table. It is thought to originate from a spill that occurred several years ago. A more thorough definition of contaminants in the northern landfill area has permitted a determination of the most hydrologically suitable sites for purge wells. In general, Concentrations found in water do not differ greatly from those observed in 1981. Since 1981, concentrations of trichloroethylene have decreased significantly in the Alert Apron plume. Near the origin of the plume, the concentration of trichloroethylene

  3. [Role of environment in complex diseases: air pollution and food contaminants].

    PubMed

    Scheen, A J; Giet, D

    2012-01-01

    Our polluted environment exposes human beings, along their life, to various toxic compounds that could trigger and aggravate different complex diseases. Such a phenomenon is well recognized for cardiovascular diseases, respiratory diseases and cancers, but other chronic inflammatory disorders may also been implicated. The most common factors, but also the most toxic, and thereby the most extensively investigated, are air pollutants (both indoor and outdoor pollution) and various contaminants present in drinking water and food (organic compounds, chemical products, heavy metals, ...). The complex interrelationships between food and pollutants, on the one hand, and between gene and environmental pollutants, including the influence of epigenetics, on the other hand, deserve further careful studies.

  4. Level-1C Product from AIRS: Principal Component Filtering

    NASA Technical Reports Server (NTRS)

    Manning, Evan M.; Jiang, Yibo; Aumann, Hartmut H.; Elliott, Denis A.; Hannon, Scott

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS), launched on the EOS Aqua spacecraft on May 4, 2002, is a grating spectrometer with 2378 channels in the range 3.7 to 15.4 microns. In a grating spectrometer each individual radiance measurement is largely independent of all others. Most measurements are extremely accurate and have very low noise levels. However, some channels exhibit high noise levels or other anomalous behavior, complicating applications needing radiances throughout a band, such as cross-calibration with other instruments and regression retrieval algorithms. The AIRS Level-1C product is similar to Level-1B but with instrument artifacts removed. This paper focuses on the "cleaning" portion of Level-1C, which identifies bad radiance values within spectra and produces substitute radiances using redundant information from other channels. The substitution is done in two passes, first with a simple combination of values from neighboring channels, then with principal components. After results of the substitution are shown, differences between principal component reconstructed values and observed radiances are used to investigate detailed noise characteristics and spatial misalignment in other channels.

  5. Novel closed-loop air-stripping process for VOC removal from contaminated water. Final report

    SciTech Connect

    Bhowmick, M.; Sontag, T.K.; Semmens, M.J.

    1990-12-05

    The study presents an approach for the treatment of contaminated groundwater, which includes Volatile Organic Compounds (VOCs) stripped from the water using hollow fiber membranes or using conventional air stripping technology and then the VOCs are oxidized in the gas phase using UV oxidation or a combination of photooxidation and photo-catalysis with Titanium Dioxide (TiO2). The work on the photooxidation of VOCs is applicable to both water and soil treatment techniques, such as air stripping and in-situ vacuum extraction. The study is divided into five major segments: Each segment includes relevant sections on the experimental methods employed, the results from the tests conducted, the development of models, and the conclusions which were drawn from the work.

  6. [Disinfectants and main sanitary and preventive measures for protection of ventilation and air-conditioning systems from Legionella contamination].

    PubMed

    Gerasimov, V N; Golov, E A; Khramov, M V; Diatlov, I A

    2008-01-01

    The study was devoted to selection and assessment of disinfecting preparations for prevention of contamination by Legionella. Using system of criteria for quality assessment of disinfectants, seven newdomestic ones belonging to quaternary ammonium compounds class or to oxygen-containing preparations and designed for disinfecting of air-conditioning and ventilation systems were selected. Antibacterial and disinfecting activities of working solutions of disinfectants were tested in laboratory on the test-surfaces and test-objects of premises' air-conditioning and ventilation systems contaminated with Legionella. High antimicrobial and disinfecting activity of new preparations "Dezactiv-M", "ExtraDez", "Emital-Garant", "Aquasept Plus", "Samarovka", "Freesept", and "Ecobreeze Oxy" during their exposure on objects and materials contaminated with Legionella was shown. Main sanitary and preventive measures for defending of air-conditioning and ventilation systems from contamination by Legionella species were presented.

  7. Potential contamination of shipboard air samples by diffusive emissions of PCBs and other organic pollutants: implications and solutions.

    PubMed

    Lohmann, Rainer; Jaward, Foday M; Durham, Louise; Barber, Jonathan L; Ockenden, Wendy; Jones, Kevin C; Bruhn, Regina; Lakaschus, Soenke; Dachs, Jordi; Booij, Kees

    2004-07-15

    Air samples were taken onboard the RRS Bransfield on an Atlantic cruise from the United Kingdom to Halley, Antarctica, from October to December 1998, with the aim of establishing PCB oceanic background air concentrations and assessing their latitudinal distribution. Great care was taken to minimize pre- and post-collection contamination of the samples, which was validated through stringent QA/QC procedures. However, there is evidence that onboard contamination of the air samples occurred,following insidious, diffusive emissions on the ship. Other data (for PCBs and other persistent organic pollutants (POPs)) and examples of shipboard contamination are presented. The implications of these findings for past and future studies of global POPs distribution are discussed. Recommendations are made to help critically appraise and minimize the problems of insidious/diffusive shipboard contamination.

  8. Regional contamination versus regional dietary differences: Understanding geographic variation in brominated and chlorinated contaminant levels in polar bears

    USGS Publications Warehouse

    McKinney, M.A.; Letcher, R.J.; Aars, J.; Born, E.W.; Branigan, M.; Dietz, R.; Evans, T.J.; Gabrielsen, G.W.; Muir, D.C.G.; Peacock, E.; Sonne, C.

    2011-01-01

    The relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (Ursus maritimus) contaminant levels is unknown. Dietary variation between Alaska Canada, East Greenland, and Svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (?? 15N, ?? 13C) and adipose fatty acid (FA) signatures relative to their main prey (ringed seals). Western and southern Hudson Bay signatures were characterized by depleted ?? 15N and ??13C, lower proportions of C20 and C22 monounsaturated FAs and higher proportions of C18 and longer chain polyunsaturated FAs. East Greenland and Svalbard signatures were reversed relative to Hudson Bay. Alaskan ?? 2011 American Chemical Society.

  9. Determinants of elite-level air rifle shooting performance.

    PubMed

    Ihalainen, S; Kuitunen, S; Mononen, K; Linnamo, V

    2016-03-01

    This study focused on identifying the most important factors determining performance in elite-level air rifle shooting technique. Forty international- and national-level shooters completed a simulated air rifle shooting competition series. From a total of 13 795 shots in 319 tests, shooting score and 17 aiming point trajectory variables were measured with an optoelectronic device and six postural balance variables were measured with force platform. Principal component analysis revealed six components in the air rifle shooting technique: aiming time, stability of hold, measurement time, cleanness of triggering, aiming accuracy, and timing of triggering. Multiple regression analysis identified four of those, namely stability of hold, cleanness of triggering, aiming accuracy, and timing of triggering as the most important predictors of shooting performance, accounting for 81% of the variance in shooting score. The direct effect of postural balance on performance was small, accounting for less than 1% of the variance in shooting score. Indirectly, the effect can be greater through a more stable holding ability, to which postural balance was correlated significantly (R = 0.55, P < 0.001). The results of the present study can be used in assessing athletes' technical strengths and weaknesses and in directing training programs on distinct shooting technical components.

  10. Evaluating the Spatial Distribution of Toxic Air Contaminants in Multiple Ecosystem Indicators in the Sierra Nevada-Southern Cascades

    NASA Astrophysics Data System (ADS)

    Nanus, L.; Simonich, S. L.; Rocchio, J.; Flanagan, C.

    2013-12-01

    Toxic air contaminants originating from agricultural areas of the Central Valley in California threaten vulnerable sensitive receptors including surface water, vegetation, snow, sediments, fish, and amphibians in the Sierra Nevada-Southern Cascades region. The spatial distribution of toxic air contaminants in different ecosystem indicators depends on variation in atmospheric concentrations and deposition, and variation in air toxics accumulation in ecosystems. The spatial distribution of organic air toxics and mercury at over 330 unique sampling locations and sample types over two decades (1990-2009) in the Sierra Nevada-Southern Cascades region were compiled and maps were developed to further understand spatial patterns and linkages between air toxics deposition and ecological effects. Potential ecosystem impacts in the Sierra Nevada-Southern Cascades region include bioaccumulation of air toxics in both aquatic and terrestrial ecosystems, reproductive disruption, and immune suppression. The most sensitive ecological end points in the region that are affected by bioaccumulation of toxic air contaminants are fish. Mercury was detected in all fish and approximately 6% exceeded human consumption thresholds. Organic air toxics were also detected in fish yielding variable spatial patterns. For amphibians, which are sensitive to pesticide exposure and potential immune suppression, increasing trends in current and historic use pesticides are observed from north to south across the region. In other indicators, such as vegetation, pesticide concentrations in lichen increase with increasing elevation. Current and historic use pesticides and mercury were also observed in snowpack at high elevations in the study area. This study shows spatial patterns in toxic air contaminants, evaluates associated risks to sensitive receptors, and identifies data gaps. Future research on atmospheric modeling and information on sources is needed in order to predict which ecosystems are the

  11. Modelled air pollution levels versus EC air quality legislation - results from high resolution simulation.

    PubMed

    Chervenkov, Hristo

    2013-12-01

    An appropriate method for evaluating the air quality of a certain area is to contrast the actual air pollution levels to the critical ones, prescribed in the legislative standards. The application of numerical simulation models for assessing the real air quality status is allowed by the legislation of the European Community (EC). This approach is preferable, especially when the area of interest is relatively big and/or the network of measurement stations is sparse, and the available observational data are scarce, respectively. Such method is very efficient for similar assessment studies due to continuous spatio-temporal coverage of the obtained results. In the study the values of the concentration of the harmful substances sulphur dioxide, (SO2), nitrogen dioxide (NO2), particulate matter - coarse (PM10) and fine (PM2.5) fraction, ozone (O3), carbon monoxide (CO) and ammonia (NH3) in the surface layer obtained from modelling simulations with resolution 10 km on hourly bases are taken to calculate the necessary statistical quantities which are used for comparison with the corresponding critical levels, prescribed in the EC directives. For part of them (PM2.5, CO and NH3) this is done for first time with such resolution. The computational grid covers Bulgaria entirely and some surrounding territories and the calculations are made for every year in the period 1991-2000. The averaged over the whole time slice results can be treated as representative for the air quality situation of the last decade of the former century.

  12. Degradation of phosphorene in air: understanding at atomic level

    NASA Astrophysics Data System (ADS)

    Wang, Gaoxue; Slough, William J.; Pandey, Ravindra; Karna, Shashi P.

    2016-06-01

    Phosphorene is a promising two-dimensional (2D) material with a direct band gap, high carrier mobility, and anisotropic electronic properties. Phosphorene-based electronic devices, however, are found to degrade upon exposure to air. In this paper, we provide an atomic level understanding of the stability of phosphorene in terms of its interaction with O2 and H2O. The results based on density functional theory together with first principles molecular dynamics calculations show that O2 could the spontaneously dissociate on phosphorene at room temperature. H2O will not strongly interact with pristine phosphorene, however, an exothermic reaction could occur if phosphorene is first oxidized. The pathway of oxidation first, followed by exothermic reaction with water is the most likely route for the chemical degradation of phosphorene-based devices in air.

  13. In situ treatment of arsenic-contaminated groundwater by air sparging.

    PubMed

    Brunsting, Joseph H; McBean, Edward A

    2014-04-01

    Arsenic contamination of groundwater is a major problem in some areas of the world, particularly in West Bengal (India) and Bangladesh where it is caused by reducing conditions in the aquifer. In situ treatment, if it can be proven as operationally feasible, has the potential to capture some advantages over other treatment methods by being fairly simple, not using chemicals, and not necessitating disposal of arsenic-rich wastes. In this study, the potential for in situ treatment by injection of compressed air directly into the aquifer (i.e. air sparging) is assessed. An experimental apparatus was constructed to simulate conditions of arsenic-rich groundwater under anaerobic conditions, and in situ treatment by air sparging was employed. Arsenic (up to 200 μg/L) was removed to a maximum of 79% (at a local point in the apparatus) using a solution with dissolved iron and arsenic only. A static "jar" test revealed arsenic removal by co-precipitation with iron at a molar ratio of approximately 2 (iron/arsenic). This is encouraging since groundwater with relatively high amounts of dissolved iron (as compared to arsenic) therefore has a large theoretical treatment capacity for arsenic. Iron oxidation was significantly retarded at pH values below neutral. In terms of operation, analysis of experimental results shows that periodic air sparging may be feasible.

  14. Uptake of toluene and ethylbenzene by plants: removal of volatile indoor air contaminants.

    PubMed

    Sriprapat, Wararat; Suksabye, Parinda; Areephak, Sirintip; Klantup, Polawat; Waraha, Atcharaphan; Sawattan, Anuchit; Thiravetyan, Paitip

    2014-04-01

    Air borne uptake of toluene and ethylbenzene by twelve plant species was examined. Of the twelve plant species examined, the highest toluene removal was found in Sansevieria trifasciata, while the ethylbenzene removal from air was with Chlorophytum comosum. Toluene and ethylbenzene can penetrate the plant׳s cuticle. However, the removal rates do not appear to be correlated with numbers of stomata per plant. It was found that wax of S. trifasciata and Sansevieria hyacinthoides had greater absorption of toluene and ethylbenzene, and it contained high hexadecanoic acid. Hexadecanoic acid might be involved in toluene and ethylbenzene adsorption by cuticles wax of plants. Chlorophyll fluorescence analysis or the potential quantum yield of PSII (Fv/Fm) in toluene exposed plants showed no significant differences between the control and the treated plants, whereas plants exposed to ethylbenzene showed significant differences or those parameters, specifically in Dracaena deremensis (Lemon lime), Dracaena sanderiana, Kalanchoe blossfeldiana, and Cordyline fruticosa. The Fv/Fm ratio can give insight into the ability of plants to tolerate (indoor) air pollution by volatile organic chemicals (VOC). This index can be used for identification of suitable plants for treating/sequestering VOCs in contaminated air.

  15. Volatilization of chemicals from tap water to indoor air from contaminated water used for showering

    SciTech Connect

    Moya, J. . National Center for Environmental Assessment); Howard-Reed, C.; Corsi, R.L. . Dept. of Civil Engineering)

    1999-07-15

    Volatile organic compounds (VOCs) may enter indoor air during the use of contaminated tap water. When this occurs, occupants can become exposed to potentially toxic VOCs via the inhalation route. The propensity for VOCs to volatilize into indoor air during the routine use of showers was investigated. A series of mass transfer experiments were conducted while a shower was operated within an enclosed chamber. Acetone, ethyl acetate, toluene, ethylbenzene, and cyclohexane were used as volatile tracers. Chemical-specific stripping efficiencies and mass transfer coefficients were determined. An assessment of the importance of gas-phase resistance to mass transfer from water to air was also completed. Chemical-specific stripping efficiencies ranged from 6.3% (for acetone) to 80% (for cyclohexane) for household showers used under normal conditions. As described in this paper, data resulting from this study allow for the determination of overall mass transfer coefficients, and corresponding volatilization rates, for any showering event and chemical of interest. As such, the information presented herein should lead to improved estimates of human inhalation exposure to toxic chemicals that volatilize from water to indoor air.

  16. Tri (2-chloroisopropyl) phosphate--an unexpected organochlorine contaminant in some charcoal air-sampling sorbent tubes

    SciTech Connect

    van Netten, C.; Brands, R.; Park, J.; Deverall, R. )

    1991-09-01

    Air sampling in a government building was necessary in response to reports of a cancer cluster. SKC (Eighty Four, Pa.) charcoal coconut shell-based sorbent tubes (226-01 lot 120) were recommended for this procedure. A recently purchased supply was present at the University of British Columbia and consequently was used for this particular study. Analysis of the front charcoal section showed the presence of a flame retardant, tri (2-chloroisopropyl) phosphate, which was confirmed by gas liquid chromatography (GLC) and mass spectrometry analysis. In an effort to identify the source of this fire retardant in the building, it became apparent from the analysis done on unknown field blanks that tri (2-chloroisopropyl) phosphate was a contaminant of the sorbent tubes used. Analysis of additional blank tubes identified the foam separators as the most likely source of contamination. Levels of tri (2-chloroisopropyl) phosphate in the front charcoal section ranged from 1.3 to 5.9 micrograms. The foam separator contained between 11.4 and 16.5 micrograms, and the backup charcoal section contained between 14.5 and 24.0 micrograms of tri (2-chloroisopropyl) phosphate. In addition, another flame retardant, tri (1,3 dichloro-2-propyl) phosphate was also found. Because these contaminants have long column retention times in GLC, it may not be apparent that these contaminants are present and consequently are likely to have modified the sorbent characteristics of the activated charcoal. Another batch of sorbent tubes bearing the same catalog number and lot number was purchased from the supplier; no flame retardants were found in this batch.

  17. High levels of contaminants in ivory gull Pagophila eburnea eggs from the Russian and Norwegian Arctic.

    PubMed

    Miljeteig, Cecilie; Strøm, Hallvard; Gavrilo, Maria V; Volkov, Andrey; Jenssen, Bjørn M; Gabrielsen, Geir W

    2009-07-15

    We found high levels of contaminants, in particular organochlorines, in eggs of the ivory gull Pagophila eburnea, a high Arctic seabird species threatened by climate change and contaminants. An 80% decline in the ivory gull breeding population in the Canadian Arctic the last two decades has been documented. Because of the dependence of the ivory gull on sea ice and its high trophic position, suggested environmental threats are climate change and contaminants. The present study investigated contaminant levels (organochlorines, brominated flame retardants, perfluorinated alkyl substances, and mercury) in ivory gull eggs from four colonies in the Norwegian (Svalbard) and Russian Arctic (Franz Josef Land and Severnaya Zemlya). The contaminant levels presented here are among the highest reported in Arctic seabird species, and we identify this as an important stressor in a species already at risk due to environmental change.

  18. Air quality in Moscow megacity: basic level and extreme cases

    NASA Astrophysics Data System (ADS)

    Pankratova, N.; Skorokhod, A.; Moiseenko, K.

    2012-04-01

    Moscow is one of the largest megacities in the world. Total annual emissions of polluting substances into the atmosphere in Moscow is likely to be about 2,0 mln. t. More than 90% of pollutants are emitted by traffic. Problem of air quality assessment is very urgent for Moscow both to alarm population and to compare with other world megacities. To study contemporary structure of atmospheric pollution over Moscow megacity data on air composition (including CO, NO, NO2, O3, CH4, CO2, SO2, NMHC, aerosol) obtained since 2002 has been analyzed. The monitoring site is located at Moscow State University meteorological observatory on South-West of Moscow. All observations are provided by A.M. Obukhov Institute of Atmospheric Physics RAS. Due to these continuous measurements typical (basic) level of pollution as well as extreme cases have been studied. The relationship between O3, NOx and VOCs were analyzed as well. Due to weather conditions (cyclonic regime is dominated) concentrations of pollutants usually do not reach dangerous levels but sometimes they are high. The case of abnormal hot and dry weather in the summer of 2010 was investigated. Many Russians were suffering from the record-breaking heat and the worst drought in 40 years. The heat was caused by very intensive and stable blocking anticyclone that established in Moscow since June, 18 till August, 18. Anticyclone of such strength has been never observed before. During 33 days in succession surface air temperature exceeded 30°C. During these 2 months troposphere over ETR was almost closed for western winds. Hot weather led to numerous forest and peat fires (about 29,000 cases) with total covered area about 12,000 km2. One of aftermaths was significant change of atmospheric composition. Many cities and settlements were covered by dense haze from fires. Evident presence of high amount of aerosol in the ambient air caused anxiety and application of safeguards. Meanwhile, less obvious increase of concentrations of

  19. Modeled occupational exposures to gas-phase medical laser-generated air contaminants.

    PubMed

    Lippert, Julia F; Lacey, Steven E; Jones, Rachael M

    2014-01-01

    Exposure monitoring data indicate the potential for substantive exposure to laser-generated air contaminants (LGAC); however the diversity of medical lasers and their applications limit generalization from direct workplace monitoring. Emission rates of seven previously reported gas-phase constituents of medical laser-generated air contaminants (LGAC) were determined experimentally and used in a semi-empirical two-zone model to estimate a range of plausible occupational exposures to health care staff. Single-source emission rates were generated in an emission chamber as a one-compartment mass balance model at steady-state. Clinical facility parameters such as room size and ventilation rate were based on standard ventilation and environmental conditions required for a laser surgical facility in compliance with regulatory agencies. All input variables in the model including point source emission rates were varied over an appropriate distribution in a Monte Carlo simulation to generate a range of time-weighted average (TWA) concentrations in the near and far field zones of the room in a conservative approach inclusive of all contributing factors to inform future predictive models. The concentrations were assessed for risk and the highest values were shown to be at least three orders of magnitude lower than the relevant occupational exposure limits (OELs). Estimated values do not appear to present a significant exposure hazard within the conditions of our emission rate estimates. PMID:24762065

  20. Acute effects of exposure to air contaminants in a sawmill on healthy volunteers.

    PubMed Central

    Dahlqvist, M; Palmberg, L; Malmberg, P; Sundblad, B M; Ulfvarson, U; Zhiping, W

    1996-01-01

    OBJECTIVES: To study whether air contaminants in sawmills can induce acute changes in the upper and lower airways of previously non-exposed subjects. METHODS: Nineteen healthy volunteers were examined to find the concentration of interleukin 6 (IL-6) in nasal lavage fluid and lung function before and after five hour exposure to dusts and fumes generated in a sawmill where timber from Scots pine was sawed. When exposed, the subjects had respirators with and without a particle filter. RESULTS: The median for daily time weighted average concentration of total dust for subjects with respirators without a filter was 0.13 mg/m3, which was significantly higher than the median of 0.04 mg/m3 for subjects who had respirators with a filter. The median for the concentration of IL-6 in the nasal lavage fluid increased after exposure from 0.5 to 5.9 pg/ml in subjects with respirators without a particle filter (P < 0.05). The increase of the concentration of IL-6 was significantly correlated with the dust concentration. A decrease in transfer factor of the lung was significantly correlated with daily time weighted average concentrations of terpenes. CONCLUSION: The findings suggest that healthy volunteers, exposed to air contaminants in a sawmill, show a slight inflammatory reaction. Also, the results of the study indicate the importance of decreasing the concentrations of wood dust in the work environment. PMID:8882114

  1. Impact of clay mineral on air oxidation of PAH-contaminated soils.

    PubMed

    Biache, Coralie; Kouadio, Olivier; Lorgeoux, Catherine; Faure, Pierre

    2014-09-01

    This work investigated the impact of a clay mineral (bentonite) on the air oxidation of the solvent extractable organic matters (EOMs) and the PAHs from contaminated soils. EOMs were isolated from two coking plant soils and mixed with silica sand or bentonite. These samples, as well as raw soils and bentonite/soil mixtures, were oxidized in air at 60 and 100 °C for 160 days. Mineralization was followed by measuring the CO2 produced over the experiments. EOM, polycyclic aromatic compound (PAC), including PAH, contents were also determined. Oxidation led to a decrease in EOM contents and PAH concentrations, these diminutions were enhanced by the presence of bentonite. Transfer of carbon from EOM to insoluble organic matter pointed out a condensation phenomenon leading to a stabilization of the contamination. Higher mineralization rates, observed during the oxidation of the soil/bentonite mixtures, seem to indicate that this clay mineral had a positive influence on the transformation of PAC into CO2.

  2. Contaminant levels in rainbow trout, Oncorhynchus mykiss, and their diets from Missouri coldwater hatcheries

    USGS Publications Warehouse

    McKee, M.J.; Kromrey, G.B.; May, T.W.; Orazio, C.E.

    2008-01-01

    Organochlorine and metal contaminants often occur in commercial fish diets and can accumulate in fish to levels of concern for human consumption. Contaminant levels were investigated in diet and rainbow trout fillets from Missouri coldwater hatcheries used in 'put and take' fisheries. The average fillet:diet ratio was <0.1 for lead and cadmium, 0.4-0.6 for organochlorine compounds, and about 0.8 for mercury. Trout fillet concentrations for all contaminants were low (<50 ng/g) and below Missouri's fish consumption advisory trigger levels. ?? 2008 Springer Science+Business Media, LLC.

  3. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Thompson, Bill

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB), initiated an investigation to evaluate a potential Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to prevent, to the extent practicable, the offsite migration of contaminated ground water from WPAFB. WPAFB retained the services of the Environmental Management Operations (EMO) and its principle subcontractor, International Technology Corporation (IT) to complete Phase 1 of the environmental investigation of ground-water contamination at WPAFB. Phase 1 of the investigation involves the short-term evaluation and potential design for a program to remove ground-water contamination that appears to be migrating across the western boundary of Area C, and across the northern boundary of Area B along Springfield Pike. Primarily, Task 4 of Phase 1 focuses on collection of information at the Area C and Springfield Pike boundaries of WPAFB. This Sampling and Analysis Plan (SAP) has been prepared to assist in completion of the Task 4 field investigation and is comprised of the Quality Assurance Project Plan (QAPP) and the Field Sampling Plan (FSP).

  4. Organophosphate Esters in Canadian Arctic Air: Occurrence, Levels and Trends.

    PubMed

    Sühring, Roxana; Diamond, Miriam L; Scheringer, Martin; Wong, Fiona; Pućko, Monika; Stern, Gary; Burt, Alexis; Hung, Hayley; Fellin, Philip; Li, Henrik; Jantunen, Liisa M

    2016-07-19

    Fourteen organophosphate esters (OPEs) were measured in the filter fraction of 117 active air samples from yearly ship-based sampling campaigns (2007-2013) and two land-based stations in the Canadian Arctic, to assess trends and long-range transport potential of OPEs. Four OPEs were detected in up to 97% of the samples, seven in 50% or less of the samples, and three were not detected. Median concentrations of ∑OPEs were 237 and 50 pg m(-3) for ship- and land-based samples, respectively. Individual median concentrations ranged from below detection to 119 pg m(-3) for ethanol, 2-chloro-, phosphate (3:1) (TCEP). High concentrations of up to 2340 pg m(-3) were observed for Tri-n-butyl phosphate (TnBP) at a land-based sampling location in Resolute Bay from 2012, whereas it was only detected in one ship-based sample at a concentration below 100 pg m(-3). Concentrations of halogenated OPEs seemed to be driven by river discharge from the Nelson and Churchill Rivers (Manitoba) and Churchill River and Lake Melville (Newfoundland and Labrador). In contrast, nonhalogenated OPE concentrations appeared to have diffuse sources or local sources close to the land-based sampling stations. Triphenyl phosphate (TPhP) showed an apparent temporal trend with a doubling-time of 11 months (p = 0.044). The results emphasize the increasing relevance of halogenated and nonhalogenated OPEs as contaminants in the Arctic.

  5. Organophosphate Esters in Canadian Arctic Air: Occurrence, Levels and Trends.

    PubMed

    Sühring, Roxana; Diamond, Miriam L; Scheringer, Martin; Wong, Fiona; Pućko, Monika; Stern, Gary; Burt, Alexis; Hung, Hayley; Fellin, Philip; Li, Henrik; Jantunen, Liisa M

    2016-07-19

    Fourteen organophosphate esters (OPEs) were measured in the filter fraction of 117 active air samples from yearly ship-based sampling campaigns (2007-2013) and two land-based stations in the Canadian Arctic, to assess trends and long-range transport potential of OPEs. Four OPEs were detected in up to 97% of the samples, seven in 50% or less of the samples, and three were not detected. Median concentrations of ∑OPEs were 237 and 50 pg m(-3) for ship- and land-based samples, respectively. Individual median concentrations ranged from below detection to 119 pg m(-3) for ethanol, 2-chloro-, phosphate (3:1) (TCEP). High concentrations of up to 2340 pg m(-3) were observed for Tri-n-butyl phosphate (TnBP) at a land-based sampling location in Resolute Bay from 2012, whereas it was only detected in one ship-based sample at a concentration below 100 pg m(-3). Concentrations of halogenated OPEs seemed to be driven by river discharge from the Nelson and Churchill Rivers (Manitoba) and Churchill River and Lake Melville (Newfoundland and Labrador). In contrast, nonhalogenated OPE concentrations appeared to have diffuse sources or local sources close to the land-based sampling stations. Triphenyl phosphate (TPhP) showed an apparent temporal trend with a doubling-time of 11 months (p = 0.044). The results emphasize the increasing relevance of halogenated and nonhalogenated OPEs as contaminants in the Arctic. PMID:27309668

  6. Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho

    USGS Publications Warehouse

    Williams, Marshall L.

    2014-01-01

    Mountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen).

  7. Alternative Methods for Assessing Contaminant Transport from the Vadose Zone to Indoor Air

    NASA Astrophysics Data System (ADS)

    Baylor, K. J.; Lee, A.; Reddy, P.; Plate, M.

    2010-12-01

    Vapor intrusion, which is the transport of contaminant vapors from groundwater and the vadose zone to indoor air, has emerged as a significant human health risk near hazardous waste sites. Volatile organic compounds (VOCs) such as trichloroethylene (TCE) and tetrachloroethylene (PCE) can volatilize from groundwater and from residual sources in the vadose zone and enter homes and commercial buildings through cracks in the slab, plumbing conduits, or other preferential pathways. Assessment of the vapor intrusion pathway typically requires collection of groundwater, soil gas, and indoor air samples, a process which can be expensive and time-consuming. We evaluated three alternative vapor intrusion assessment methods, including 1) use of radon as a surrogate for vapor intrusion, 2) use of pressure differential measurements between indoor/outdoor and indoor/subslab to assess the potential for vapor intrusion, and 3) use of passive, longer-duration sorbent methods to measure indoor air VOC concentrations. The primary test site, located approximately 30 miles south of San Francisco, was selected due to the presence of TCE (10 - 300 ug/L) in shallow groundwater (5 to 10 feet bgs). At this test site, we found that radon was not a suitable surrogate to asses vapor intrusion and that pressure differential measurements are challenging to implement and equipment-intensive. More significantly, we found that the passive, longer-duration sorbent methods are easy to deploy and compared well quantitatively with standard indoor air sampling methods. The sorbent technique is less than half the cost of typical indoor air methods, and also provides a longer duration sample, typically 3 to 14 days rather than 8 to 24 hours for standard methods. The passive sorbent methods can be a reliable, cost-effective, and easy way to sample for TCE, PCE and other VOCs as part of a vapor intrusion investigation.

  8. Effects of H2O, CO2, and N2 air contaminants on critical airside strain rates for extinction of hydrogen-air counterflow diffusion flames

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.; Northam, G. B.; Wilson, L. G.; Guerra, Rosemary

    1989-01-01

    Dish-shaped counterflow diffusion flames centered by opposing laminar jets of H2 and clean and contaminant O2/N2 mixtures in an argon bath at 1 atm were used to study the effects of contaminants on critical airside strain. The jet velocities for both flame extinction and restoration are found for a wide range of contaminant and O2 concentrations in the air jet. The tests are also conducted for a variety of input H2 concentrations. The results are compared with those from several other studies.

  9. Risk factors for microbial contamination in fruits and vegetables at the preharvest level: a systematic review.

    PubMed

    Park, Sangshin; Szonyi, Barbara; Gautam, Raju; Nightingale, Kendra; Anciso, Juan; Ivanek, Renata

    2012-11-01

    The objective of this study was to perform a systematic review of risk factors for contamination of fruits and vegetables with Listeria monocytogenes, Salmonella, and Escherichia coli O157:H7 at the preharvest level. Relevant studies were identified by searching six electronic databases: MEDLINE, EMBASE, CAB Abstracts, AGRIS, AGRICOLA, and FSTA, using the following thesaurus terms: L. monocytogenes, Salmonella, E. coli O157 AND fruit, vegetable. All search terms were exploded to find all related subheadings. To be eligible, studies had to be prospective controlled trials or observational studies at the preharvest level and had to show clear and sufficient information on the process in which the produce was contaminated. Of the 3,463 citations identified, 68 studies fulfilled the eligibility criteria. Most of these studies were on leafy greens and tomatoes. Six studies assessed produce contamination with respect to animal host-related risk factors, and 20 studies assessed contamination with respect to pathogen characteristics. Sixty-two studies assessed the association between produce contamination and factors related to produce, water, and soil, as well as local ecological conditions of the production location. While evaluations of many risk factors for preharvest-level produce contamination have been reported, the quality assessment of the reviewed studies confirmed the existence of solid evidence for only some of them, including growing produce on clay-type soil, the application of contaminated or non-pH-stabilized manure, and the use of spray irrigation with contaminated water, with a particular risk of contamination on the lower leaf surface. In conclusion, synthesis of the reviewed studies suggests that reducing microbial contamination of irrigation water and soil are the most effective targets for the prevention and control of produce contamination. Furthermore, this review provides an inventory of the evaluated risk factors, including those requiring more

  10. Risk factors for microbial contamination in fruits and vegetables at the preharvest level: a systematic review.

    PubMed

    Park, Sangshin; Szonyi, Barbara; Gautam, Raju; Nightingale, Kendra; Anciso, Juan; Ivanek, Renata

    2012-11-01

    The objective of this study was to perform a systematic review of risk factors for contamination of fruits and vegetables with Listeria monocytogenes, Salmonella, and Escherichia coli O157:H7 at the preharvest level. Relevant studies were identified by searching six electronic databases: MEDLINE, EMBASE, CAB Abstracts, AGRIS, AGRICOLA, and FSTA, using the following thesaurus terms: L. monocytogenes, Salmonella, E. coli O157 AND fruit, vegetable. All search terms were exploded to find all related subheadings. To be eligible, studies had to be prospective controlled trials or observational studies at the preharvest level and had to show clear and sufficient information on the process in which the produce was contaminated. Of the 3,463 citations identified, 68 studies fulfilled the eligibility criteria. Most of these studies were on leafy greens and tomatoes. Six studies assessed produce contamination with respect to animal host-related risk factors, and 20 studies assessed contamination with respect to pathogen characteristics. Sixty-two studies assessed the association between produce contamination and factors related to produce, water, and soil, as well as local ecological conditions of the production location. While evaluations of many risk factors for preharvest-level produce contamination have been reported, the quality assessment of the reviewed studies confirmed the existence of solid evidence for only some of them, including growing produce on clay-type soil, the application of contaminated or non-pH-stabilized manure, and the use of spray irrigation with contaminated water, with a particular risk of contamination on the lower leaf surface. In conclusion, synthesis of the reviewed studies suggests that reducing microbial contamination of irrigation water and soil are the most effective targets for the prevention and control of produce contamination. Furthermore, this review provides an inventory of the evaluated risk factors, including those requiring more

  11. Assessment of ground-water contamination at Wurtsmith Air Force Base, Michigan, 1982-85

    USGS Publications Warehouse

    Cummings, T.R.; Twenter, F.R.

    1986-01-01

    Study of ground-water contamination at Wurtsmith Air Force Base, Michigan, defined the movement and distribution of volatile organic compounds in the glacial sand and gravel aquifer at known sites of contamination, and has defined new plumes at two other sites. The Arrow Street purge system, installed in 1982 to remove contaminants from the Building 43 plume, has lowered concentrations of trichloroethylene (TCE) in groundwater in the central part of the most contaminated area from a range of 1,000 to 2,000 microg/L to about 200 microg/L. TCE is not escaping off-Base from this area. In the southern part of the Base a plume containing principally TCE and dichloroethylene (DCE) has been delineated along Mission Drive. Maximum concentrations observed were 3,290 microg/L of TCE and 1,480 microg/L of DCE. Hydrologically suitable sites for purge wells were identified in the southern part of the plume using a new ground-water flow model of the Base. A benzene plume near the bulk-fuel storage area has shifted to a more northerly direction under influence of the Arrow Street purge system. Sites initially identified for purging the benzene plume have been repositioned because of the change in contaminant movement. JP-4 fuel was found to be accumulating in wells near the bulk-fuel storage area, largely in response to seasonal fluctuations in the water-table. It is thought to originate from a spill that occurred several years ago. In general, concentrations found in water do not differ greatly from those observed in 1981. Since 1981, concentrations of TCE have decreased significantly in the Alert Apron plume. Near the origin of the plume, the concentration of TCE has decreased from 1,000 microg/L in 1980 to 50 microg/L in 1984. Water from Van Etten Lake near the termination of the plume had only a trace of TCE at one site. Benzene detected in water from well AF2 seems to originate near the former site of buried fuel tanks west of the operational apron. During periods of normal

  12. Asthma and low level air pollution in Helsinki

    SciTech Connect

    Poenkae A5 )

    1991-09-01

    The effects of relatively low levels of air pollution and weather conditions on the number of patients who had asthma attacks and who were admitted to a hospital were studied in Helsinki during a 3-y period. The number of admissions increased during cold weather (n = 4,209), especially among persons who were of working age but not among children. Even after standardization for temperature, all admissions, including emergency ward admissions, were significantly correlated with ambient air concentrations of nitrogen dioxide (NO2), nitric oxide (NO), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and total suspended particulates (TSP). Regression analysis revealed that NO and O3 were most strongly associated with asthma problems. Effects of air pollutants and cold were maximal if they occurred on the same day, except for O3, which had a more pronounced effect after a 1-d lag. The associations between pollutants, low temperature, and admissions were most significant among adults of working age, followed by the elderly. Among children, only O3 and NO were significantly correlated with admissions. Levels of pollutants were fairly low, the long-term mean being 19.2 micrograms/m3 for SO2, 38.6 micrograms/m3 for NO2, 22.0 micrograms/m3 or O3, and 1.3 mg/m3 for CO. In contrast, the mean concentration of TSP was high (76.3 micrograms/m3), and the mean temperature was low (+ 4.7 degrees C). These results suggest that concentrations of pollutants lower than those given as guidelines in many countries may increase the incidence of asthma attacks.

  13. Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings

    PubMed Central

    Beamer, P.I.; Sugeng, A. J.; Kelly, M.D.; Lothrop, N.; Klimecki, W.; Wilkinson, S.T.; Loh, M.

    2014-01-01

    Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p<0.05), whose primary source in indoor air is resuspended soil from outdoors. In the second rural community, our estimated metal concentrations in air were comparable to active air sampling measurements taken previously. This passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites. PMID:24469149

  14. Opposed jet burner studies of hydrogen combustion with pure and N2, NO-contaminated air

    NASA Technical Reports Server (NTRS)

    Guerra, Rosemary; Pellett, Gerald L.; Northam, G. Burton; Wilson, Lloyd G.

    1987-01-01

    A counterflow diffusion flame formed by an argon-bathed tubular-opposed jet burner (OJB) was used to determine the 'blowoff' and 'restore' combustion characteristics for jets of various H2/N2 mixtures and for jets of air contaminated by NO (which normally occurs in high-enthalpy airflows supplied to hypersonic test facilities for scramjet combustors). Substantial divergence of 'blowoff' and 'restore' limits occurred as H2 mass flux, M(H)2, increased, the H2 jet became richer, and the M(air)/M(H2 + N2) ratio increased from 1 to 3 (molar H2/O2 from 1 to 16). Both OJB limits were sensitive to reactant composition. One to six percent NO in air led to significant N2-corrected decreases in the M(H2) values for 'blowoff' (2-8 percent) and 'restore' (6-12 percent) for mole fractions of H2 ranging from 0.5 to 0.95. However, when H2/O2 was held constant, all N2-corrected changes in M(H2) were negligible.

  15. High Concentrations of Organic Contaminants in Air from Ship Breaking Activities in Chittagong, Bangladesh.

    PubMed

    Nøst, Therese H; Halse, Anne K; Randall, Scott; Borgen, Anders R; Schlabach, Martin; Paul, Alak; Rahman, Atiqur; Breivik, Knut

    2015-10-01

    The beaches on the coast of Chittagong in Bangladesh are one of the most intense ship breaking areas in the world. The aim of the study was to measure the concentrations of organic contaminants in the air in the city of Chittagong, including the surrounding ship breaking areas using passive air samplers (N = 25). The compounds detected in the highest amounts were the polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs), whereas dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs) were several orders of magnitude lower in comparison. PCBs, PAHs, and HCB were highest at sites near the ship breaking activities, whereas DDTs and SCCPs were higher in the urban areas. Ship breaking activities likely act as atmospheric emission sources of PCBs, PAHs, and HCB, thus adding to the international emphasis on responsible recycling of ships. Concentrations of PAHs, PCBs, DDTs, HCB, and SCCPs in ambient air in Chittagong are high in comparison to those found in similar studies performed in other parts of Asia. Estimated toxic equivalent quotients indicate elevated human health risks caused by inhalation of PAHs at most sites. PMID:26351879

  16. High Concentrations of Organic Contaminants in Air from Ship Breaking Activities in Chittagong, Bangladesh.

    PubMed

    Nøst, Therese H; Halse, Anne K; Randall, Scott; Borgen, Anders R; Schlabach, Martin; Paul, Alak; Rahman, Atiqur; Breivik, Knut

    2015-10-01

    The beaches on the coast of Chittagong in Bangladesh are one of the most intense ship breaking areas in the world. The aim of the study was to measure the concentrations of organic contaminants in the air in the city of Chittagong, including the surrounding ship breaking areas using passive air samplers (N = 25). The compounds detected in the highest amounts were the polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs), whereas dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs) were several orders of magnitude lower in comparison. PCBs, PAHs, and HCB were highest at sites near the ship breaking activities, whereas DDTs and SCCPs were higher in the urban areas. Ship breaking activities likely act as atmospheric emission sources of PCBs, PAHs, and HCB, thus adding to the international emphasis on responsible recycling of ships. Concentrations of PAHs, PCBs, DDTs, HCB, and SCCPs in ambient air in Chittagong are high in comparison to those found in similar studies performed in other parts of Asia. Estimated toxic equivalent quotients indicate elevated human health risks caused by inhalation of PAHs at most sites.

  17. Tropospheric gas at potentially toxic levels in air

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-08-01

    Forest fires and emission of air pollutants, such as fumes from vehicles running on diesel and slow burning of coal and charcoal, release isocyanic acid in the troposphere. In 2011, scientists first detected isocyanic acid in the ambient atmosphere at levels toxic to human populations; at concentrations exceeding 1 part per billion by volume (ppbv), human beings could experience tissue decay when exposed to the toxin. For the first time, using a chemical transport model designed to estimate the distribution and budget of isocyanic acid in the troposphere, Young et al. showed that in several parts of the world, local emissions may increase the concentration of isocyanic acid in the ambient atmosphere, thereby exposing large populations to potentially toxic levels of the acid.

  18. Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping: Scoping Report

    SciTech Connect

    Looney, B.B.

    2000-08-18

    Data collected during the first stage of a Savannah River Technology Center (SRTC) Strategic Research and Development Project confirmed the efficacy of chemical reduction and air stripping/sparging as an ultralow level mercury treatment concept for waters containing Hg(II). The process consists of dosing the water with low levels of stannous chloride to convert the mercury to Hg. This form of mercury can easily be removed from the water by air stripping or sparging. Samples of Savannah River Site (SRS) groundwater containing approximately 130 ng/L of total mercury (as Hg(II)) were used for the study. In undosed samples, sparging removed 0 percent of the initial mercury. In the dosed samples, all of the removals were greater than 94 percent, except in one water type at one dose. This sample, which was saturated with dissolved oxygen, showed a 63 percent reduction in mercury following treatment at the lowest dose. Following dosing at minimally effective levels and sparging, treated water contained less than 10 ng/L total mercury. In general, the data indicate that the reduction of mercury is highly favored and that stannous chloride reagent efficiently targets the Hg(II) contaminant in the presence of competing reactions. Based on the results, the authors estimated that the costs of implementing and operating an ultralow level mercury treatment process based on chemical reduction and stripping/sparging are 10 percent to 20 percent of traditional treatment technologies.

  19. Blood lead levels in children and environmental lead contamination in Miami inner city, Florida.

    PubMed

    Gasana, Janvier; Hlaing, WayWay M; Siegel, Kristy A; Chamorro, Armando; Niyonsenga, Theophile

    2006-09-01

    Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL) as low as 10 microg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 microg/dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 microg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05). However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami.

  20. Blood Lead Levels in Children and Environmental Lead Contamination in Miami Inner City, Florida

    PubMed Central

    Gasana, Janvier; Hlaing, WayWay M.; Siegel, Kristy A.; Chamorro, Armando; Niyonsenga, Theophile

    2006-01-01

    Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL) as low as 10 μg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 μg/dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 μg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05). However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami. PMID:16968968

  1. Simultaneous measurements of wire electrode surface contamination and corona discharge characteristics in an air-cleaning electrostatic precipitator

    SciTech Connect

    Kanazawa, Seiji; Ohkubo, Toshikazu; Nomoto, Yukiharu; Adachi, Takayoshi; Chang, J.S.

    1997-01-01

    Contamination of the corona wire in a wire-to-plate type air-cleaning electrostatic precipitator is studied experimentally. In order to enhance the contamination of wire, air containing dusts is directly supplied to a part of the wire electrode. Spores of Lycopodium and cigarette smoke particles are used as test dusts. Simultaneous measurements of wire electrode optical images and corona discharge modes are carried out during contamination processes. Results show that corona discharge modes and optical emission from the wire electrode change with time due to the surface contamination. In the case of cigarette smoke, after a time elapsed, streamer coronas appear due to the buildup of smoke particles on the wire surface. After the first streamer generation, the corona current fluctuates with time because the formation and diminution of the projections occur alternately at the different parts on the wire electrode surface.

  2. An evaluation of antifungal agents for the treatment of fungal contamination in indoor air environments.

    PubMed

    Rogawansamy, Senthaamarai; Gaskin, Sharyn; Taylor, Michael; Pisaniello, Dino

    2015-06-01

    Fungal contamination in indoor environments has been associated with adverse health effects for the inhabitants. Remediation of fungal contamination requires removal of the fungi present and modifying the indoor environment to become less favourable to growth.  This may include treatment of indoor environments with an antifungal agent to prevent future growth. However there are limited published data or advice on chemical agents suitable for indoor fungal remediation. The aim of this study was to assess the relative efficacies of five commercially available cleaning agents with published or anecdotal use for indoor fungal remediation. The five agents included two common multi-purpose industrial disinfectants (Cavicide® and Virkon®), 70% ethanol, vinegar (4.0%-4.2% acetic acid), and a plant-derived compound (tea tree (Melaleuca alternifolia) oil) tested in both a liquid and vapour form. Tea tree oil has recently generated interest for its antimicrobial efficacy in clinical settings, but has not been widely employed for fungal remediation. Each antifungal agent was assessed for fungal growth inhibition using a disc diffusion method against a representative species from two common fungal genera, (Aspergillus fumigatus and Penicillium chrysogenum), which were isolated from air samples and are commonly found in indoor air. Tea tree oil demonstrated the greatest inhibitory effect on the growth of both fungi, applied in either a liquid or vapour form. Cavicide® and Virkon® demonstrated similar, although less, growth inhibition of both genera. Vinegar (4.0%-4.2% acetic acid) was found to only inhibit the growth of P. chrysogenum, while 70% ethanol was found to have no inhibitory effect on the growth of either fungi. There was a notable inhibition in sporulation, distinct from growth inhibition after exposure to tea tree oil, Virkon®, Cavicide® and vinegar. Results demonstrate that common cleaning and antifungal agents differ in their capacity to inhibit the growth

  3. An evaluation of antifungal agents for the treatment of fungal contamination in indoor air environments.

    PubMed

    Rogawansamy, Senthaamarai; Gaskin, Sharyn; Taylor, Michael; Pisaniello, Dino

    2015-06-02

    Fungal contamination in indoor environments has been associated with adverse health effects for the inhabitants. Remediation of fungal contamination requires removal of the fungi present and modifying the indoor environment to become less favourable to growth.  This may include treatment of indoor environments with an antifungal agent to prevent future growth. However there are limited published data or advice on chemical agents suitable for indoor fungal remediation. The aim of this study was to assess the relative efficacies of five commercially available cleaning agents with published or anecdotal use for indoor fungal remediation. The five agents included two common multi-purpose industrial disinfectants (Cavicide® and Virkon®), 70% ethanol, vinegar (4.0%-4.2% acetic acid), and a plant-derived compound (tea tree (Melaleuca alternifolia) oil) tested in both a liquid and vapour form. Tea tree oil has recently generated interest for its antimicrobial efficacy in clinical settings, but has not been widely employed for fungal remediation. Each antifungal agent was assessed for fungal growth inhibition using a disc diffusion method against a representative species from two common fungal genera, (Aspergillus fumigatus and Penicillium chrysogenum), which were isolated from air samples and are commonly found in indoor air. Tea tree oil demonstrated the greatest inhibitory effect on the growth of both fungi, applied in either a liquid or vapour form. Cavicide® and Virkon® demonstrated similar, although less, growth inhibition of both genera. Vinegar (4.0%-4.2% acetic acid) was found to only inhibit the growth of P. chrysogenum, while 70% ethanol was found to have no inhibitory effect on the growth of either fungi. There was a notable inhibition in sporulation, distinct from growth inhibition after exposure to tea tree oil, Virkon®, Cavicide® and vinegar. Results demonstrate that common cleaning and antifungal agents differ in their capacity to inhibit the growth

  4. An Evaluation of Antifungal Agents for the Treatment of Fungal Contamination in Indoor Air Environments

    PubMed Central

    Rogawansamy, Senthaamarai; Gaskin, Sharyn; Taylor, Michael; Pisaniello, Dino

    2015-01-01

    Fungal contamination in indoor environments has been associated with adverse health effects for the inhabitants. Remediation of fungal contamination requires removal of the fungi present and modifying the indoor environment to become less favourable to growth.  This may include treatment of indoor environments with an antifungal agent to prevent future growth. However there are limited published data or advice on chemical agents suitable for indoor fungal remediation. The aim of this study was to assess the relative efficacies of five commercially available cleaning agents with published or anecdotal use for indoor fungal remediation. The five agents included two common multi-purpose industrial disinfectants (Cavicide® and Virkon®), 70% ethanol, vinegar (4.0%−4.2% acetic acid), and a plant-derived compound (tea tree (Melaleuca alternifolia) oil) tested in both a liquid and vapour form. Tea tree oil has recently generated interest for its antimicrobial efficacy in clinical settings, but has not been widely employed for fungal remediation. Each antifungal agent was assessed for fungal growth inhibition using a disc diffusion method against a representative species from two common fungal genera, (Aspergillus fumigatus and Penicillium chrysogenum), which were isolated from air samples and are commonly found in indoor air. Tea tree oil demonstrated the greatest inhibitory effect on the growth of both fungi, applied in either a liquid or vapour form. Cavicide® and Virkon® demonstrated similar, although less, growth inhibition of both genera. Vinegar (4.0%–4.2% acetic acid) was found to only inhibit the growth of P. chrysogenum, while 70% ethanol was found to have no inhibitory effect on the growth of either fungi. There was a notable inhibition in sporulation, distinct from growth inhibition after exposure to tea tree oil, Virkon®, Cavicide® and vinegar. Results demonstrate that common cleaning and antifungal agents differ in their capacity to inhibit the

  5. Air modelling as an alternative to sampling for low-level radioactive airborne releases

    SciTech Connect

    Morgenstern, M.Y.; Hueske, K.

    1995-05-01

    This paper describes our efforts to assess the effect of airborne releases at one DOE laboratory using air modelling based on historical data. Among the facilities affected by these developments is Los Alamos National Laboratory (LANL) in New Mexico. RCRA, as amended by the Hazardous and Solid Waste Amendments (HSWA) in 1984, requires all facilities which involve the treatment, storage, and disposal of hazardous waste obtain a RCRA/HSWA waste facility permit. LANL complied with CEARP by initiating a process of identifying potential release sites associated with LANL operations prior to filing a RCRA/HSWA permit application. In the process of preparing the RCRA/HSWA waste facility permit application to the U.S. Environmental Protection Agency (EPA), a total of 603 Solid Waste Management Units (SWMUs) were identified as part of the requirements of the HSWA Module VIH permit requirements. The HSWA Module VIII permit requires LANL to determine whether there have been any releases of hazardous waste or hazardous constituents from SWMUs at the facility dating from the 1940`s by performing a RCRA Facility Investigation to address known or suspected releases from specified SWMUs to affected media (i.e. soil, groundwater, surface water, and air). Among the most troublesome of the potential releases sites are those associated with airborne radioactive releases. In order to assess health risks associated with radioactive contaminants in a manner consistent with exposure standards currently in place, the DOE and LANL have established Screening Action Levels (SALs) for radioactive soil contamination. The SALs for each radionuclide in soil are derived from calculations based on a residential scenario in which individuals are exposed to contaminated soil via inhalation and ingestion as well as external exposure to gamma emitters in the soil. The applicable SALs are shown.

  6. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 5, Field Investigation report

    SciTech Connect

    Not Available

    1992-03-01

    An environmental investigation of ground water conditions has been undertaken at Wright-Patterson Air Force Base (WPAFB), Ohio to obtain data to assist in the evaluation of a potential removal action to prevent, to the extent practicable, migration of the contaminated ground water across Base boundaries. Field investigations were limited to the central section of the southwestern boundary of Area C and the Springfield Pike boundary of Area B. Further, the study was limited to a maximum depth of 150 feet below grade. Three primary activities of the field investigation were: (1) installation of 22 monitoring wells, (2) collection and analysis of ground water from 71 locations, (3) measurement of ground water elevations at 69 locations. Volatile organic compounds including trichloroethylene, perchloroethylene, and/or vinyl chloride were detected in concentrations exceeding Maximum Contaminant Levels (MCL) at three locations within the Area C investigation area. Ground water at the Springfield Pike boundary of Area B occurs in two primary units, separated by a thicker-than-expected clay layers. One well within Area B was determined to exceed the MCL for trichloroethylene.

  7. Contaminant effect endpoints in terrestrial vertebrates at and above the individual level

    USGS Publications Warehouse

    Rattner, B.A.; Cohen, J.B.; Golden, N.H.; Albers, P.H.; Heinz, G.H.; Ohlendorf, H.M.

    2000-01-01

    Use of biochemical, physiological, anatomical, reproductive and behavioral characteristics of wild terrestrial vertebrates to assess contaminant exposure and effects has become commonplace over the past 3 decades. At the level of the individual organism, response patterns have been associated with and sometimes causally linked to contaminant exposure. However, such responses at the organismal level are rarely associated with or causally linked to effects at the population level. Although the ultimate goal of ecotoxicology is the protection of populations, communities, and ecosystems, most of the existing science and regulatory legislation focus on the level of the individual. Consequently, much of this overview concentrates on contaminant effects at the organismal level, with some extrapolation to higher-level effects. In this chapter, we review the state of the science for the evaluation of biotic end-points used to assess contaminant exposure and effects at or above the level of the individual. In addition, we describe extant contaminant concentration thresholds, guidelines, or standards (toxicant criteria) in environmental matrices (e.g., water, soil, sediment, foods) that have been developed to protect wild terrestrial vertebrates. Suggestions are provided to develop and embellish the use and value of such endpoints and criteria for extrapolation of effects to higher levels of biological organization. Increasing focus on populations, communities, and ecosystems is needed to develop biologically meaningful regulatory guidelines that will protect natural resources.

  8. 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.

  9. Opposed jet burner studies of effects of CO, CO2, and N2 air-contaminants on hydrogen-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Guerra, Rosemary; Pellett, Gerald L.; Northam, G. Burton; Wilson, Lloyd G.

    1987-01-01

    The blowoff/restore characteristics for jets of various H2/N2 mixtures opposed to jets of air contaminated by N2, CO, and CO2 have been determined using a counterflow diffusion flame formed by a tubular opposed jet burner. Both blowoff and restore limits are found to be sensitive to fuel and air composition. Empirically derived variations in the limits of the average mass flux of incoming H2 with percent contaminant, at fixed incoming fuel and H2/O2 inputs, are used to quantify the effects of oxygen dilution, flame augmentation, and flame retardation by N2, CO, and CO2 contaminants. The implications of the results are discussed.

  10. Air and blood lead levels in a battery factory.

    PubMed

    Ibiebele, D D

    1994-08-01

    Chronic exposure of acid-lead battery factory workers to lead was assessed by determining blood lead levels (PbB) in 80 blood samples obtained from 20 workers and relating the values to lead in air (PbA) values in 80 air samples collected at four operational areas. All the samples were analyzed for lead by atomic absorption spectrophotometry. The geometric means of PbA at the sampling areas were: 92.01 micrograms/m3 in the casting and pasting area; 85.73 micrograms/m3 in the assembly line area; 36.31 micrograms/m3 in the battery charging and sales area; and 4.2 micrograms/m3 in the administration area. The corresponding PbB values were 32.19 micrograms/dl, 35.42 micrograms/dl, 17.33 micrograms/dl and 7.78 micrograms/dl, respectively. The correlations between the PbA and PbB were positive for all the areas and also for the dry and wet seasons. The possibility of predicting PbB by monitoring PbA needs to be evaluated.

  11. Evaluation of bacterial contamination on surgical drapes following use of the Bair Hugger(®) forced air warming system.

    PubMed

    Occhipinti, Lindsay L; Hauptman, Joe G; Greco, Justin J; Mehler, Stephen J

    2013-12-01

    This pilot study determined the rate of bacterial contamination on surgical drapes of small animal patients warmed intra-operatively with the Bair Hugger(®) forced air warming system compared to a control method. Surgical drapes of 100 patients undergoing clean surgical procedures were swabbed with aerobic culturettes at the beginning and end of surgery. Samples were cultured on Trypticase soy agar. Contamination of the surgical drapes was identified in 6/98 cases (6.1%). There was no significant difference in the number of contaminated surgical drapes between the Bair Hugger(®) and control groups (P = 0.47).

  12. Development and Testing of an Air Fluorescence Imaging System for the Detection of Radiological Contamination

    SciTech Connect

    Inrig, Elizabeth; Koslowsky, Vern; Andrews, Bob; Dick, Michael; Forget, Patrick; Ing, Harry; Hugron, Roger; Wong, Larry

    2011-12-13

    Detection of radionuclides emitting short-range radiation, such as {alpha} and low-energy {beta} particles, has always presented a challenge, particularly when such radionuclides are dispersed over a wide area. In this situation, conventional detection methods require the area of interest to be surveyed using a fragile probe at very close range--a slow, error-prone, and potentially dangerous process that may take many hours for a single room. The instrument under development uses a novel approach by imaging radiation-induced fluorescence in the air surrounding a contaminated area, rather than detecting the radiation directly. A robust and portable system has been designed and built that will allow contaminated areas to be rapidly detected and delineated. The detector incorporates position-sensitive photo-multiplier tubes, UV filters, a fast electronic shutter and an aspherical phase mask that significantly increases the depth-of-field. Preliminary tests have been conducted using sealed {sup 241}Am sources of varying activities and surface areas. The details of the instrument design will be described and the results of recent testing will be presented.

  13. Thermal degradation of diesel-contaminated peats in an air atmosphere

    SciTech Connect

    Ghaly, R.A.; Ugursal, V.I.; Ghaly, A.E.; Mansaray, K.G.

    1999-06-01

    Peat, plant matter that is partially fossilized, is formed in poorly oxygenated wetlands where the rate at which the plant matter accumulates is greater than the rate at which it decomposes. Peat is a common solid fuel ranked among coal, coke, wood, and sugarcane bagasse. Peat has also been used to recover oil during the soil and water remediation processes. However, industrial utilization of peat in thermochemical conversion systems to liberate energy requires the knowledge of its thermal characteristics. In this study, the thermal behavior of peat (both uncontaminated and diesel-contaminated) was examined at three heating rates (10, 20, and 50 C/min) in a stationary air atmosphere using a thermogravimetric analysis technique between ambient temperature (25 C) and 600 C. The thermal degradation rate in active and passive pyrolysis zones, the initial degradation temperature, and the residual weight at 600 C were determined. Increasing the heating rate increased both the thermal degradation rate and the residual weight at 600 C and decreased the initial degradation temperature. The residual weight at 600 C was less than the ash content in all of the peat samples indicating the burnout of some of the mineral oxides, which have low melting and boiling temperatures, such as K{sub 2}O and P{sub 2}O. The results provide useful information about utilization of diesel-contaminated peat in thermochemical conversion systems, especially gasifiers, because of its high energy content and low ash content.

  14. The Influence of Declining Air Lead Levels on Blood Lead-Air Lead Slope Factors in Children

    EPA Science Inventory

    This presentation describes calculation of blood lead-air lead slope factor within an analysis of the relationship between blood lead levels and air lead levels among participants in the National Health and Nutrition Examination Survey (NHANES). The slope factors are compared wi...

  15. Level of chemical and microbiological contaminations in chili bo (paste).

    PubMed

    Zaini, Nurul Aqilah Mohd; Harith, Hanis Hazeera; Olusesan, Akanbi Taiwo; Zulkifli, Anwarul Hidayah; Bakar, Fatimah Abu; Osman, Azizah; Hamid, Azizah Abd; Saari, Nazamid

    2010-03-01

    The objective of this study was to determine the level of preservatives and microbiological loads in various brands of commercially available chili bo (paste). Fifteen different brands of chili bo obtained from the local market and hypermarkets were analyzed for pH, moisture and benzoic acid content, microbiological loads (aerobic, anaerobic, aerobic spores, and fungi), and thermophilic microorganisms. Results showed that both moisture content and pH vary among samples. The concentrations of benzoic acid detected in chili bo were found to be in the range of 537 to 5,435 mg/kg. Nine of fifteen brands were found to exceed the maximum level permitted by the Malaysian Food Law in accordance with the Codex Alimentarius (1,000 mg/kg for benzoic acid). An apparent correlation between benzoic acid concentration and microbiological loads present in the chili bo was observed. The microbiological loads were found to be relatively low in the end products containing high amounts of benzoic acid. The heat-resistant (70 to 80 degrees C) microorganisms present in chili bo were identified as Ochrobacterum tritici, Stenotrophomonas rhizophila, Microbacterium maritypicum, Roseomonas spp., CDC group II-E subgroup A, Flavimonas oryzihabitans, and Pseudomonas aeruginosa, with M. maritypicum being the most frequently found (in 9 of 15 samples) microorganism. Most of these identified microorganisms were not known to cause foodborne illnesses.

  16. Level of chemical and microbiological contaminations in chili bo (paste).

    PubMed

    Zaini, Nurul Aqilah Mohd; Harith, Hanis Hazeera; Olusesan, Akanbi Taiwo; Zulkifli, Anwarul Hidayah; Bakar, Fatimah Abu; Osman, Azizah; Hamid, Azizah Abd; Saari, Nazamid

    2010-03-01

    The objective of this study was to determine the level of preservatives and microbiological loads in various brands of commercially available chili bo (paste). Fifteen different brands of chili bo obtained from the local market and hypermarkets were analyzed for pH, moisture and benzoic acid content, microbiological loads (aerobic, anaerobic, aerobic spores, and fungi), and thermophilic microorganisms. Results showed that both moisture content and pH vary among samples. The concentrations of benzoic acid detected in chili bo were found to be in the range of 537 to 5,435 mg/kg. Nine of fifteen brands were found to exceed the maximum level permitted by the Malaysian Food Law in accordance with the Codex Alimentarius (1,000 mg/kg for benzoic acid). An apparent correlation between benzoic acid concentration and microbiological loads present in the chili bo was observed. The microbiological loads were found to be relatively low in the end products containing high amounts of benzoic acid. The heat-resistant (70 to 80 degrees C) microorganisms present in chili bo were identified as Ochrobacterum tritici, Stenotrophomonas rhizophila, Microbacterium maritypicum, Roseomonas spp., CDC group II-E subgroup A, Flavimonas oryzihabitans, and Pseudomonas aeruginosa, with M. maritypicum being the most frequently found (in 9 of 15 samples) microorganism. Most of these identified microorganisms were not known to cause foodborne illnesses. PMID:20202342

  17. The advantages and disadvantages of centralized control of air power at operational level

    NASA Astrophysics Data System (ADS)

    Arisoy, Uǧur

    2014-05-01

    People do not want to see and hear a war. In today's world, if war is inevitable, the use of air power is seen as the preferable means of conducting operations instead of financially burdensome land battles which are more likely to cause heavy loss of life. The use of Air Power has gained importance in NATO operations in the Post-Cold War era. For example, air power has undertaken a decisive role from the beginning to the end of the operation in Libya. From this point of view, the most important issue to consider is how to direct air power more effectively at operational level. NATO's Core JFAC (Joint Force Air Command) was established in 2012 to control joint air power at operational level from a single center. US had experienced JFAC aproach in the Operation Desert Storm in 1991. UK, France, Germany, Italy and Spain are also directing their air power from their JFAC structures. Joint air power can be directed from a single center at operational level by means of JFAC. JFAC aproach provides complex planning progress of Air Power to be controled faster in a single center. An Air Power with a large number of aircrafts, long range missiles of cutting-edge technology may have difficulties in achieving results unless directed effectively. In this article, directing air power more effectively at operational level has been studied in the framework of directing air power from a single center carried out by SWOT analysis technique. "Directing Air Power at operational level from a single center similar to JFAC-like structure" is compared with "Directing Air Power at operational level from two centers similar to AC (Air Command) + CAOC (Combined Air Operations Center) structure" As a result of this study, it is assessed that directing air power at operational level from a single center would bring effectiveness to the air campaign. The study examines directing air power at operational level. Developments at political, strategic and tactical levels have been ignored.

  18. Air purification from TCE and PCE contamination in a hybrid bioreactors and biofilter integrated system.

    PubMed

    Tabernacka, Agnieszka; Zborowska, Ewa; Lebkowska, Maria; Borawski, Maciej

    2014-01-15

    A two-stage waste air treatment system, consisting of hybrid bioreactors (modified bioscrubbers) and a biofilter, was used to treat waste air containing chlorinated ethenes - trichloroethylene (TCE) and tetrachloroethylene (PCE). The bioreactor was operated with loadings in the range 0.46-5.50gm(-3)h(-1) for TCE and 2.16-9.02gm(-3)h(-1) for PCE. The biofilter loadings were in the range 0.1-0.97gm(-3)h(-1) for TCE and 0.2-2.12gm(-3)h(-1) for PCE. Under low pollutant loadings, the efficiency of TCE elimination was 23-25% in the bioreactor and 54-70% in the biofilter. The efficiency of PCE elimination was 44-60% in the bioreactor and 50-75% in the biofilter. The best results for the bioreactor were observed one week after the pollutant loading was increased. However, the process did not stabilize. In the next seven days contaminant removal efficiency, enzymatic activity and biomass content were all diminished.

  19. Prevalence and contamination levels of listeria monocytogenes in ready-to-eat foods in Tokyo, Japan

    PubMed Central

    SHIMOJIMA, Yukako; IDA, Miki; NAKAMA, Akiko; NISHINO, Yukari; FUKUI, Rie; KURODA, Sumiyo; HIRAI, Akihiko; KAI, Akemi; SADAMASU, Kenji

    2016-01-01

    We surveyed prevalence and contamination levels of Listeria monocytogenes in ready-to-eat foods between 2000 and 2012 in Tokyo. L. monocytogenes was isolated from 52 (1.7%) out of 2,980 samples. Comparing the prevalence in the study period, 2.2% were positive in the former period (2000–2005) and 1.2% in the latter (2006–2012). Using the most probable number (MPN) technique, 32 samples were contaminated with fewer than 0.3 L. monocytogenes/g, 10 samples with 0.3–1.0/g and 4 samples with more than 1.0/g (the maximum was 2.3/g). The most common serovar was 1/2a, followed by 1/2b, 4b and 1/2c. We revealed that ready-to-eat foods in Tokyo were contaminated with L. monocytogenes, although the contamination levels were low. PMID:27000951

  20. Cat serum contamination by phthalates, PCBs, and PBDEs versus food and indoor air.

    PubMed

    Braouezec, Clélie; Enriquez, Brigitte; Blanchard, Martine; Chevreuil, Marc; Teil, Marie-Jeanne

    2016-05-01

    A wide variety of endocrine disrupting compounds (EDCs) with semi-volatile properties are emitted to indoor air and, thus, humans might get exposed to these compounds. Pet cats spend the major part of their lifetime at home and might integrate indoor contamination so that they could mirror the human exposure. Three classes of EDCs, polybromodiphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and phthalates (PAEs), were simultaneously considered and quantified in the serum of cats (Felis silvestris catus) living in the Paris area (France). The main compound concentrations by decreasing importance order were as follows: for PAEs, di-n-butyl phthalate (79,900 ng L(-1)) next di-iso-butyl phthalate (53,200 ng L(-1)), di-iso-nonyl phthalate (43,800 ng L(-1)), and di-ethylhexyl phthalate (32,830 ng L(-1)); for PCBs, CB153 (1378 ng L(-1)) next CB52 (509 ng L(-1)), CB101 (355 ng L(-1)), CB110 (264 ng L(-1)), and CB118 (165 ng L(-1)); and for PBDEs, BDE 153/154 (35 ng L(-1)) next BDE47 (10.7 ng L(-1)). Total serum concentrations as mean ± standard deviation were 107 ± 98 μg L(-1) for ∑9PAEs, 2799 ± 944 ng L(-1) for ∑19PCBs, and 56 ± 21 ng L(-1) for ∑9BDEs. The three chemical groups were found in cat food: 0.088 ng g(-1) for ∑9BDEs, 1.7 ng g(-1) for ∑19PCBs, and 2292 ng g(-1) for ∑9PAEs and in indoor air: 0.063 ng m(-3) for ∑9BDEs, 1.5 ng m(-3) for ∑19PCBs, and 848 ng m(-3) for ∑9PAEs. Contaminant intake by food ingestion was approximately 100-fold higher than that by indoor air inhalation.

  1. Biomarker responses and decreasing contaminant levels in ringed seals (Pusa hispida) from Svalbard, Norway.

    PubMed

    Wolkers, Hans; Krafft, Bjørn A; van Bavel, Bert; Helgason, Lisa B; Lydersen, Christian; Kovacs, Kit M

    2008-01-01

    Blubber was analyzed for a wide range of contaminants from five sub-adult and eight adult male ringed seals sampled in 2004, namely, for polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), toxaphenes, chlordanes, dichlorodiphenyldichloroethylene (DDE), and polybrominated diphenylethers (PBDEs). Contaminant levels were compared to previously sampled animals from the same area, as well as data from literature for other arctic wildlife species from a wide variety of locations. Ringed seals sampled in 2004 showed 50-90% lower levels of legacy contaminants such as PCBs and chlorinated pesticides compared to animals sampled in 1996 of similar age (14 sub-adults and 7 adult males), indicating that the decline of chlorinated contaminants observed during the 1990s in a variety of arctic wildlife species is continuing into the 21st century. The results also indicated that PBDE declined in ringed seals; levels in 2004 were about 70-80% lower than in animals sampled in 1998. This is one of the first observations of reduced exposure to these compounds and might be a first indication that restrictions of production and use of these contaminants have resulted in lower exposures in the Arctic. The PCB pattern shifted toward the less chlorinated (i.e., less persistent) PCBs, especially in adult ringed seals, possibly as a result of reduced overall contaminant exposures and a consequently lower cytochrome P-450 (CYP) induction, which results in a slower metabolism of less persistent PCBs. The overall effect would be relative increases in the lower chlorinated PCBs and a relative decreases in the higher chlorinated PCB. Possibly due to low exposure and consequent low induction levels, ethoxyresorufin O-deethylation (EROD) activity proved to be a poor biomarker for contaminant exposure in ringed seals in the present study. The close negative correlation (r(2) = 70.9%)between EROD activity and percent blubber indicates that CYP might respond to increased bioavailability of the

  2. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium... paragraph. Table A—BAT for Radionuclides Listed in § 141.66 Contaminant BAT Combined radium-226 and radium...-3,300 3,300-10,000 Combined radium-226 and radium-228 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6,...

  3. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium... paragraph. Table A—BAT for Radionuclides Listed in § 141.66 Contaminant BAT Combined radium-226 and radium...-3,300 3,300-10,000 Combined radium-226 and radium-228 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6,...

  4. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium... paragraph. Table A—BAT for Radionuclides Listed in § 141.66 Contaminant BAT Combined radium-226 and radium...-3,300 3,300-10,000 Combined radium-226 and radium-228 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6,...

  5. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium... paragraph. Table A—BAT for Radionuclides Listed in § 141.66 Contaminant BAT Combined radium-226 and radium...-3,300 3,300-10,000 Combined radium-226 and radium-228 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6,...

  6. 40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium... paragraph. Table A—BAT for Radionuclides Listed in § 141.66 Contaminant BAT Combined radium-226 and radium...-3,300 3,300-10,000 Combined radium-226 and radium-228 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6,...

  7. Correlation of BTEX levels and toxicity of condensate contaminated groundwater

    SciTech Connect

    Headley, J.; Goudey, S.; Birkholz, D.; Hardisty, P.

    1995-12-31

    The concentration of BTEX was determined for 60 groundwater samples collected from 6 gas plants in Western Canada, using conventional purge-and-trap GC/MS procedures. The gas plants were selected to cover different types of operations with different amine process chemicals employed for the sweetening of the raw sour-gas condensates. Aliquots of the ground water samples were subjected to toxicity screening tests, specifically, (a) bacterial luminescence (microtox) ; (b) daphnia mortality and (c) fathead minnow mortality. For the toxicity tests, sample handling procedures were developed to minimize the loss of volatile organics during the experiments. To account for possible losses, the levels of BTEX were monitored at the start and upon completion of these tests. The results indicated that the toxicity of the groundwater was in general, well correlated to the concentration of BTEX (primarily xylene). Approximately 5% of the samples, however, were observed to be toxic although the concentration of BTEX were below the method detection limit (1 {micro}g/1). Thiophenic volatile organics were implicated for the latter. Based on the laboratory results, the remediation of BTEX is expected to correlate with the removal of the toxicity of the groundwater. These findings are of direct relevance to present technologies employed for remediation of ground water at the Sourgas plants.

  8. Phytoremediation of benzene, toluene, ethylbenzene and xylene contaminated air by D. deremensis and O. microdasys plants

    PubMed Central

    2014-01-01

    Background People usually spent about 90% of their time indoors, which are probably more polluted than outside the buildings. High levels of volatile organic compounds (VOCs) are known as causes of sick building syndrome. The present study was designed to determine the quantitative effects of some plants to improve the quality of the environmental air. Results D. deremensis and O. microdasys were chosen for the present study. There is no report of using O. microdasys for cleaning the air from pollutants. So, in this study, the effectiveness of O. microdasys in air removing from pollutants was studied and compared with D. dermensis. O. microdasys plant can remove 2 ppm concentration benzene, toluene, xylene and ethylbenzene from air in test chambers completely after 48, 55, 47 and 57 hours, respectively. The removal rates of benzene, toluene, xylene and ethylbenzene (BTEX) from air in the test chambers were 1.18, 0.54, 1.64 and 1.35 mg/ m2d1, respectively. Conclusions If an office containing 2.5 ppm of each of BTEX and had an approximate volume of 30 m3, it contains 16, 8, 22 and 22 mg/m3 benzene, toluene, xylene and ethylbenzene, respectively. Using ten O. microdasys pots with the same size used in this study, can remove benzene, toluene, xylene and ethylbenzene totally after 36, 40, 30 and 39 hours. The authors recommended studying the efficiency of the plants for removal of BTEX from air at higher range of concentrations such as 20-30 ppm. PMID:24451679

  9. Contamination of indoor dust and air by polychlorinated biphenyls and brominated flame retardants and relevance of non-dietary exposure in Vietnamese informal e-waste recycling sites.

    PubMed

    Tue, Nguyen Minh; Takahashi, Shin; Suzuki, Go; Isobe, Tomohiko; Viet, Pham Hung; Kobara, Yuso; Seike, Nobuyasu; Zhang, Gan; Sudaryanto, Agus; Tanabe, Shinsuke

    2013-01-01

    This study investigated the occurrence of polychlorinated biphenyls (PCBs), and several additive brominated flame retardants (BFRs) in indoor dust and air from two Vietnamese informal e-waste recycling sites (EWRSs) and an urban site in order to assess the relevance of these media for human exposure. The levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in settled house dust from the EWRSs (130-12,000, 5.4-400, 5.2-620 and 31-1400 ng g(-1), respectively) were significantly higher than in urban house dust but the levels of PCBs (4.8-320 ng g(-1)) were not higher. The levels of PCBs and PBDEs in air at e-waste recycling houses (1000-1800 and 620-720 pg m(-3), respectively), determined using passive sampling, were also higher compared with non-e-waste houses. The composition of BFRs in EWRS samples suggests the influence from high-temperature processes and occurrence of waste materials containing older BFR formulations. Results of daily intake estimation for e-waste recycling workers are in good agreement with the accumulation patterns previously observed in human milk and indicate that dust ingestion contributes a large portion of the PBDE intake (60%-88%), and air inhalation to the low-chlorinated PCB intake (>80% for triCBs) due to their high levels in dust and air, respectively. Further investigation of both indoor dust and air as the exposure media for other e-waste recycling-related contaminants and assessment of health risk associated with exposure to these contaminant mixtures is necessary.

  10. Air mercury contamination in the gold mining town of Portovelo, Ecuador.

    PubMed

    González-Carrasco, Víctor; Velasquez-Lopez, Patricio C; Olivero-Verbel, Jesús; Pájaro-Castro, Nerlis

    2011-09-01

    Portovelo is one of the oldest gold mining towns in Ecuador. Artisanal gold mining still uses mercury in the process of gold recovery. In this study, mercury concentrations in the air of Portovelo were evaluated. High mercury levels in the ambient were found in El Pache sector, where most gold mining processing plants are located. These varied between 2,356.7 ± 1,807.6 and 3,699.5 ± 1,225.3 ng/m(3) during the rainy and dry seasons, respectively. Lower levels were detected in the urban (central) area of Portovelo, with 214.6 ± 43.7 ng/m(3) in the rainy season and 574.2 ± 72.8 ng/m(3) in the dry season, exceeding the Agency for Toxic Substances and Disease Registry minimum risk level of 200 ng/m(3). Average mercury concentrations in exhaled air from miners, measured before and after amalgam burning ranged between 179-1,352 and 2,007-3,389 ng/m(3), respectively. These data suggest Portovelo air is polluted with mercury and humans are being dangerously exposed. Therefore, strong actions must be undertaken to protect human and environmental health, including changing gold recovery systems.

  11. Air mercury contamination in the gold mining town of Portovelo, Ecuador.

    PubMed

    González-Carrasco, Víctor; Velasquez-Lopez, Patricio C; Olivero-Verbel, Jesús; Pájaro-Castro, Nerlis

    2011-09-01

    Portovelo is one of the oldest gold mining towns in Ecuador. Artisanal gold mining still uses mercury in the process of gold recovery. In this study, mercury concentrations in the air of Portovelo were evaluated. High mercury levels in the ambient were found in El Pache sector, where most gold mining processing plants are located. These varied between 2,356.7 ± 1,807.6 and 3,699.5 ± 1,225.3 ng/m(3) during the rainy and dry seasons, respectively. Lower levels were detected in the urban (central) area of Portovelo, with 214.6 ± 43.7 ng/m(3) in the rainy season and 574.2 ± 72.8 ng/m(3) in the dry season, exceeding the Agency for Toxic Substances and Disease Registry minimum risk level of 200 ng/m(3). Average mercury concentrations in exhaled air from miners, measured before and after amalgam burning ranged between 179-1,352 and 2,007-3,389 ng/m(3), respectively. These data suggest Portovelo air is polluted with mercury and humans are being dangerously exposed. Therefore, strong actions must be undertaken to protect human and environmental health, including changing gold recovery systems. PMID:21769613

  12. Numeric removal action levels for contaminated drinking water sites. Update 2. Directive

    SciTech Connect

    1995-03-01

    This document is an updated table of numeric action levels for contaminated drinking water sites. It was originally published as an attachment to 9360.1-02 (Oct. 93) which described the new methodology used by OERR to calculate removal action levels (RALs) in drinking water.

  13. Hot air injection for removal of dense, non-aqueous-phase liquid contaminants from low-permeability soils

    SciTech Connect

    Payne, F.C.

    1996-08-01

    The performance of soil vapor extraction systems for the recovery of volatile and semi-volatile organic compounds is potentially enhanced by the injection of heated air to increase soil temperatures. The soil temperature increase is expected to improve soil vapor extraction (SVE) performance by increasing target compound vapor pressures and by increasing soil permeability through drying. The vapor pressure increase due to temperature rise relieves the vapor pressure limit on the feasibility of soil vapor extraction. However, the system still requires an air flow through the soil system to deliver heat and to recover mobilized contaminants. Although the soil permeability can be increased through drying, very low permeability soils and low permeability soils adjacent to high permeability air flow pathways will be treated slowly, if at all. AR thermal enhancement methods face this limitation. Heated air injection offers advantages relative to other thermal techniques, including low capital and operation costs. Heated air injection is at a disadvantage relative to other thermal techniques due to the low heat capacity of air. To be effective, heated air injection requires that higher air flows be established than for steam injection or radio frequency heating. Heated air injection is not economically feasible for the stratified soil system developed as a standard test for this document. This is due to the inability to restrict heated air flow to the clay stratum when a low-resistance air flow pathway is available in the adjoining sand. However, the technology should be especially attractive, both technically and economically, for low-volatile contaminant recovery from relatively homogeneous soil formations. 16 refs., 2 tabs.

  14. Assessment of natural attenuation of ground-water contamination at sites FT03, LF13, and WP14/LF15, Dover Air Force Base, Delaware

    USGS Publications Warehouse

    Barbaro, Jeffrey R.

    2002-01-01

    Water-quality, aquifer-sediment, and hydro-logic data were used to assess the effectiveness of natural attenuation of ground-water contamination at Fire Training Area Three, the Rubble Area Landfill, the Liquid Waste Disposal Landfill, and the Receiver Station Landfill in the East Management Unit of Dover Air Force Base, Delaware. These sites, which are contaminated with chlorinated solvents and fuel hydrocarbons, are under-going long-term monitoring to determine if natural attenuation continues to sufficiently reduce contaminant concentrations to meet regulatory requirements. This report is the first assessment of the effectiveness of natural attenuation at these sites since long-term monitoring began in 1999, and follows a preliminary investigation done in 1995?96. This assessment was done by the U.S. Geological Survey in cooperation with the U.S. Air Force.Since 1995?96, additional information has been collected and used in the current assessment. The conclusions in this report are based primarily on ground-water samples collected from January through March 2000. Previous analytical results from selected wells, available geologic and geo-physical well logs, and newly acquired information such as sediment organic-carbon measurements, hydraulic-conductivity measurements determined from slug tests on wells in the natural attenuation study area, and water-level measurements from surficial-aquifer wells also were used in this assessment. This information was used to: (1) calculate retardation factors and estimate contaminant migration velocities, (2) improve estimates of ground-water flow directions and inferred contaminant migration pathways, (3) better define the areal extent of contamination and the proximity of contaminants to discharge areas and the Base boundary, (4) develop a better under-standing of the vertical variability of contaminant concentrations and redox conditions, (5) evaluate the effects of temporal changes on concentrations in the plumes and

  15. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and...

  16. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and...

  17. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and...

  18. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and...

  19. 42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.140 Section 84.140 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and...

  20. Contamination in Fractured-Rock Aquifers - Research at the former Naval Air Warfare Center, West Trenton, New Jersey

    USGS Publications Warehouse

    Goode, Daniel J.; Tiedeman, Claire R.; Lacombe, Pierre J.; Imbrigiotta, Thomas E.; Shapiro, Allen M.; Chapelle, Francis H.

    2007-01-01

    The U.S. Geological Survey and cooperators are studying chlorinated solvents in a fractured sedimentary rock aquifer underlying the former Naval Air Warfare Center (NAWC), West Trenton, New Jersey. Fractured-rock aquifers are common in many parts of the United States and are highly susceptible to contamination, particularly at industrial sites. Compared to 'unconsolidated' aquifers, there can be much more uncertainty about the direction and rate of contaminant migration and about the processes and factors that control chemical and microbial transformations of contaminants. Research at the NAWC is improving understanding of the transport and fate of chlorinated solvents in fractured-rock aquifers and will compare the effectiveness of different strategies for contaminant remediation.

  1. 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.

  2. Bioaccumulation Potential Of Air Contaminants: Combining Biological Allometry, Chemical Equilibrium And Mass-Balances To Predict Accumulation Of Air Pollutants In Various Mammals

    SciTech Connect

    Veltman, Karin; McKone, Thomas E.; Huijbregts, Mark A.J.; Hendriks, A. Jan

    2009-03-01

    In the present study we develop and test a uniform model intended for single compartment analysis in the context of human and environmental risk assessment of airborne contaminants. The new aspects of the model are the integration of biological allometry with fugacity-based mass-balance theory to describe exchange of contaminants with air. The developed model is applicable to various mammalian species and a range of chemicals, while requiring few and typically well-known input parameters, such as the adult mass and composition of the species, and the octanol-water and air-water partition coefficient of the chemical. Accumulation of organic chemicals is typically considered to be a function of the chemical affinity forlipid components in tissues. Here, we use a generic description of chemical affinity for neutral and polar lipids and proteins to estimate blood-air partition coefficients (Kba) and tissue-air partition coefficients (Kta) for various mammals. This provides a more accurate prediction of blood-air partition coefficients, as proteins make up a large fraction of total blood components. The results show that 75percent of the modeled inhalation and exhalation rate constants are within a factor of 2 from independent empirical values for humans, rats and mice, and 87percent of the predicted blood-air partition coefficients are within a factor of 5 from empirical data. At steady-state, the bioaccumulation potential of air pollutants is shown to be mainly a function of the tissue-air partition coefficient and the biotransformation capacity of the species and depends weakly on the ventilation rate and the cardiac output of mammals.

  3. Increased prevalence of IgG-induced sensitization and hypersensitivity pneumonitis (humidifier lung) in nonsmokers exposed to aerosols of a contaminated air conditioner.

    PubMed

    Baur, X; Richter, G; Pethran, A; Czuppon, A B; Schwaiblmair, M

    1992-01-01

    Specific IgG antibodies against antigens of a contaminated air conditioner were estimated in serum of 134 workers of a printing company. Altogether 64% of the workers investigated revealed significantly elevated levels (> 3 U/ml) of IgG antibodies specific to these antigens as compared to a nonexposed control group. The occurrence of IgG antibodies for microbial extracts were 25% for Fusarium, 23% for Penicillium notatum, 13% for Alternaria tenuis, 12% for Aureobasidium pullulans, 9% for Sphaeropsidales species, 3% for Micropolyspora faeni, 2% for Aspergillus fumigatus and 2% for Thermoactionomyces vulgaris. Out of the 86 workers with elevated IgG antibodies for air conditioner antigens, 59 were nonsmokers. Considering a cut-off level of 10 U/ml IgG for high values, the proportion of smokers to nonsmokers becomes even more pronounced (6 to 36 respectively, binominal test p < 0.001). This is despite the fact that the distribution of smokers and nonsmokers among the 134 workers is approximately equal (60 to 74). All 3 workers with clinical diagnosis of humidifier lung or humidifier fever belonged to the nonsmoker group. Our findings indicate that crude water extracts of contaminated air conditioners are the best choice as antigen source for the diagnosis of humidifier lung in exposed workers. Nonsmokers are shown to have a high risk for immunological sensitization. PMID:1485005

  4. Entrainment of Upper Level Dry Air Into Hurricane Earl

    NASA Technical Reports Server (NTRS)

    Guillory, Anthony R.; Jedlovec, Gary J.; Hood, Robbie E.; Atkinson, Robert J.; LaFontaine, Frank J.

    1999-01-01

    Hurricane Earl formed in the Gulf of Mexico in September 1998. It quickly was upgraded from a tropical disturbance to tropical storm status and then to a hurricane. Earl possessed hybrid (tropical and extratropical) characteristics throughout its lifetime. The system maintained and erratic track, which led to wide variability in the operational track forecasts. It eventually made landfall on the Florida panhandle on 2 September and raced northeastward. During August and September 1998, NASA conducted the third Convection and Moisture Experiment (CAMEX-3). The experiment was focused on studying hurricanes with an emphasis toward developing a better understanding of their intensification and motion. Earl provides a unique opportunity to utilize high spatial and temporal resolution data collected from the DC-8 and high altitude ER-2 NASA platforms, which flew over Earl as it made landfall. These data can also be put into broader view provided by other instruments from the Geosynchronous Operational Environmental Satellites (GOES) and the Tropical Rainfall Measuring Mission (TRMM) satellites. Hurricane Earl was affected by entrainment of dry air from the northwest. Hurricane Isis was intensifying and approaching the Mexican Pacific coast with its associated outflow potentially affecting the inflow into Earl as the storm neared Florida. In addition, a longwave synoptic trough circulation was present over the eastern U.S. Either or both of these could be responsible for the dry air into the system. This paper will focus on identifying the source of the dry by using upper-level wind and moisture fields derived from the GOES 6.7 um water vapor imagery. We will attempt to relate the large-scale observations to those from the NASA aircraft. An infrared instrument onboard the ER-2 also has a similar wavelength and may be able to confirm some of the GOES findings. In addition, a microwave radiometer with 4 channels focused on measuring precipitation and its associated ice

  5. Factors affecting xylene-contaminated air removal by the ornamental plant Zamioculcas zamiifolia.

    PubMed

    Sriprapat, Wararat; Boraphech, Phattara; Thiravetyan, Paitip

    2014-02-01

    Fifteen plant species-Alternanthera bettzickiana, Drimiopsis botryoides, Aloe vera, Chlorophytum comosum, Aglaonema commutatum, Cordyline fruticosa, Philodendron martianum, Sansevieria hyacinthoides, Aglaonema rotundum, Fittonia albivenis, Muehlenbeckia platyclada, Tradescantia spathacea, Guzmania lingulata, Zamioculcas zamiifolia, and Cyperus alternifolius-were evaluated for the removal efficiency of xylene from contaminated air. Among the test plants, Z. zamiifolia showed the highest xylene removal efficiency. Xylene was toxic to Z. zamiifolia with an LC50 of 3,464 ppm. Higher concentrations of xylene exhibited damage symptoms, including leaf tips turning yellow, holonecrosis, and hydrosis. TEM images showed that a low concentration of xylene vapors caused minor changes in the chloroplast, while a high concentration caused swollen chloroplasts and damage. The effect of photosynthetic types on xylene removal efficiency suggests that a mixture of Z. zamiifolia, S. hyacinthoides, and A. commutatum which represent facultative CAM, CAM, and C3 plants, is the most suitable system for xylene removal. Therefore, for maximum improvement in removing xylene volatile compounds under various conditions, multiple species are needed. The effect of a plant's total leaf area on xylene removal indicates that at lower concentrations of xylene, a small leaf area might be as efficient as a large leaf area.

  6. Utilization of air pollution control residues for the stabilization/solidification of trace element contaminated soil.

    PubMed

    Travar, I; Kihl, A; Kumpiene, J

    2015-12-01

    The aim of this study was to evaluate the stabilization/solidification (S/S) of trace element-contaminated soil using air pollution control residues (APCRs) prior to disposal in landfill sites. Two soil samples (with low and moderate concentrations of organic matter) were stabilized using three APCRs that originated from the incineration of municipal solid waste, bio-fuels and a mixture of coal and crushed olive kernels. Two APCR/soil mixtures were tested: 30% APCR/70% soil and 50% APCR/50% soil. A batch leaching test was used to study immobilization of As and co-occurring metals Cr, Cu, Pb and Zn. Solidification was evaluated by measuring the unconfined compression strength (UCS). Leaching of As was reduced by 39-93% in APCR/soil mixtures and decreased with increased amounts of added APCR. Immobilization of As positively correlated with the amount of Ca in the APCR and negatively with the amount of soil organic matter. According to geochemical modelling, the precipitation of calcium arsenate (Ca3(AsO4)2/4H2O) and incorporation of As in ettringite (Ca6Al2(SO4)3(OH)12 · 26H2O) in soil/APCR mixtures might explain the reduced leaching of As. A negative effect of the treatment was an increased leaching of Cu, Cr and dissolved organic carbon. Solidification of APCR/soil was considerably weakened by soil organic matter.

  7. Bilirubin oxidase based enzymatic air-breathing cathode: Operation under pristine and contaminated conditions.

    PubMed

    Santoro, Carlo; Babanova, Sofia; Erable, Benjamin; Schuler, Andrew; Atanassov, Plamen

    2016-04-01

    The performance of bilirubin oxidase (BOx) based air breathing cathode was constantly monitored over 45 days. The effect of electrolyte composition on the cathode oxygen reduction reaction (ORR) output was investigated. Particularly, deactivation of the electrocatalytic activity of the enzyme in phosphate buffer saline (PBS) solution and in activated sludge (AS) was evaluated. The greatest drop in current density was observed during the first 3 days of constant operation with a decrease of ~60 μA cm(-2) day(-1). The rate of decrease slowed to ~10 μA cm(-2) day(-1) (day 3 to 9) and then to ~1.5 μA cm(-2)day(-1) thereafter (day 9 to 45). Despite the constant decrease in output, the BOx cathode generated residual current after 45 days operations with an open circuit potential (OCP) of 475 mV vs. Ag/AgCl. Enzyme deactivation was also studied in AS to simulate an environment close to the real waste operation with pollutants, solid particles and bacteria. The presence of low-molecular weight soluble contaminants was identified as the main reason for an immediate enzymatic deactivation within few hours of cathode operation. The presence of solid particles and bacteria does not affect the natural degradation of the enzyme.

  8. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    SciTech Connect

    Not Available

    1992-04-01

    This Removal Action System Design has been prepared as a Phase I Volume for the implementation of the Phase II removal action at Wright-Patterson Air Force Base (WPAFB) near Dayton, Ohio. The objective of the removal action is to prevent, to the extent practicable, the migration of ground water contaminated with chlorinated volatile organic compounds (VOCS) across the southwest boundary of Area C. The Phase 1, Volume 9 Removal Action System Design compiles the design documents prepared for the Phase II Removal Action. These documents, which are presented in Appendices to Volume 9, include: Process Design, which presents the 30 percent design for the ground water treatment system (GWTS); Design Packages 1 and 2 for Earthwork and Road Construction, and the Discharge Pipeline, respectively; no drawings are included in the appendix; Design Package 3 for installation of the Ground Water Extraction Well(s); Design Package 4 for installation of the Monitoring Well Instrumentation; and Design Package 5 for installation of the Ground Water Treatment System; this Design Package is incorporated by reference because of its size.

  9. Factors affecting xylene-contaminated air removal by the ornamental plant Zamioculcas zamiifolia.

    PubMed

    Sriprapat, Wararat; Boraphech, Phattara; Thiravetyan, Paitip

    2014-02-01

    Fifteen plant species-Alternanthera bettzickiana, Drimiopsis botryoides, Aloe vera, Chlorophytum comosum, Aglaonema commutatum, Cordyline fruticosa, Philodendron martianum, Sansevieria hyacinthoides, Aglaonema rotundum, Fittonia albivenis, Muehlenbeckia platyclada, Tradescantia spathacea, Guzmania lingulata, Zamioculcas zamiifolia, and Cyperus alternifolius-were evaluated for the removal efficiency of xylene from contaminated air. Among the test plants, Z. zamiifolia showed the highest xylene removal efficiency. Xylene was toxic to Z. zamiifolia with an LC50 of 3,464 ppm. Higher concentrations of xylene exhibited damage symptoms, including leaf tips turning yellow, holonecrosis, and hydrosis. TEM images showed that a low concentration of xylene vapors caused minor changes in the chloroplast, while a high concentration caused swollen chloroplasts and damage. The effect of photosynthetic types on xylene removal efficiency suggests that a mixture of Z. zamiifolia, S. hyacinthoides, and A. commutatum which represent facultative CAM, CAM, and C3 plants, is the most suitable system for xylene removal. Therefore, for maximum improvement in removing xylene volatile compounds under various conditions, multiple species are needed. The effect of a plant's total leaf area on xylene removal indicates that at lower concentrations of xylene, a small leaf area might be as efficient as a large leaf area. PMID:24091527

  10. Analysis of industrial contaminants in indoor air: part 1. Volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons and polychlorinated biphenyls.

    PubMed

    Barro, Ruth; Regueiro, Jorge; Llompart, María; Garcia-Jares, Carmen

    2009-01-16

    This article reviews recent literature on the analysis of industrial contaminants in indoor air in the framework of the REACH project, which is mainly intended to improve protection of human health and the environment from the risks of more than 34 millions of chemical substances. Industrial pollutants that can be found in indoor air may be of very different types and origin, belonging to the volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) categories. Several compounds have been classified into the priority organic pollutants (POPs) class such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/PCDFs) and related polychlorinated compounds, and polycyclic aromatic hydrocarbons (PAHs). Many of these compounds are partially associated to the air gas phase, but also to the suspended particulate matter. Furthermore, settled dust can act as a concentrator for the less volatile pollutants and has become a matrix of great concern for indoors contamination. Main literature considered in this review are papers from the last 10 years reporting analytical developments and applications regarding VOCs, aldehydes and other carbonyls, PCBs, PCDDs, PCDFs, and PAHs in the indoor environment. Sample collection and pretreatment, analyte extraction, clean-up procedures, determination techniques, performance results, as well as compound concentrations in indoor samples, are summarized and discussed. Emergent contaminants and pesticides related to the industrial development that can be found in indoor air are reviewed in a second part in this volume.

  11. Effects of H2O, CO2, and N2 Air Contaminants on Critical Airside Strain Rates for Extinction of Hydrogen-Air Counterflow Diffusion Flames

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.; Wilson, L. G.; Northam, G. B.; Guerra, Rosemary

    1989-01-01

    Coaxial tubular opposed jet burners (OJB) were used to form dish shaped counterflow diffusion flames (CFDF), centered by opposing laminar jets of H2, N2 and both clean and contaminated air (O2/N2 mixtures) in an argon bath at 1 atm. Jet velocities for flame extinction and restoration limits are shown versus wide ranges of contaminant and O2 concentrations in the air jet, and also input H2 concentration. Blowoff, a sudden breaking of CFDF to a stable ring shape, occurs in highly stretched stagnation flows and is generally believed to measure kinetically limited flame reactivity. Restore, a sudden restoration of central flame, is a relatively new phenomenon which exhibits a H2 dependent hysteresis from Blowoff. For 25 percent O2 air mixtures, mole for mole replacement of 25 percent N2 contaminant by steam increased U(air) or flame strength at Blowoff by about 5 percent. This result is consistent with laminar burning velocity results from analogous substitution of steam for N2 in a premixed stoichiometric H2-O2-N2 (or steam) flame, shown by Koroll and Mulpuru to promote a 10 percent increase in experimental and calculated laminar burning velocity, due to enhanced third body efficiency of water in: H + O2 + M yields HO2 + M. When the OJB results were compared with Liu and MacFarlane's experimental laminar burning velocity of premixed stoichiometric H2 + air + steam, a crossover occurred, i.e., steam enhanced OJB flame strength at extinction relative to laminar burning velocity.

  12. 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

  13. 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.

  14. Contaminant levels and toxicity of sediments and water of Baltimore Harbor and Back River, Maryland

    SciTech Connect

    Logan, D.T.; Jacobs, F.; Mehrotra, N.

    1995-12-31

    The Patapsco and Back River Watershed drains the Baltimore metropolitan area, Maryland`s most heavily industrialized and urbanized region. Due to the intensive development and industrialization of the Baltimore metropolitan area over the past 250 years, high levels of contaminants have been discharged into Baltimore Harbor on the Patapsco River and into the Back River. Pollutants historically discharged include heavy metals, petroleum hydrocarbons, pesticides, cyanide, sewage, other organic chemicals, and nutrients. Sources have included industrial and municipal discharges, sewerage overflows, urban runoff, and leaks and spills from vessels and on-land facilities. The Maryland Department of the Environment undertook this study of ambient conditions as part of a developing strategy to assess and improve conditions in the Chesapeake Bay and its tributaries. Past studies were compiled, evaluated, and synthesized to identify the areas of degraded conditions and contaminants of possible concern. Sediment contaminant levels were assessed using historical sediment chemistry data, Effects Range Low and Median concentrations (ER-L and ER-M) as toxicological benchmarks, and a sum of toxicity units approach for multiple contaminants. Data on toxicity testing and biological monitoring was compared to sediment and water quality data. Fish tissue data were used to examine bioaccumulated chemicals. A computerized Geographical Information System (GIS) was used to manipulate and display complex geographical data. The final identification of areas and chemicals of potential concern relied on a syntheses of these results as well as information on present and past contaminant loadings.

  15. Investigation of indoor air volatile organic compounds concentration levels in dental settings and some related methodological issues.

    PubMed

    Santarsiero, Anna; Fuselli, Sergio; Piermattei, Alessandro; Morlino, Roberta; De Blasio, Giorgia; De Felice, Marco; Ortolani, Emanuela

    2009-01-01

    The assessment of indoor air volatile organic compounds (VOCs) concentration levels in dental settings has a big health relevance for the potentially massive occupational exposure to a lot of diverse contaminants. The comparison of the VOCs profile relative to indoor conditions and to the corresponding outdoor concentrations, as well as the discovery of possible correlations between specific dental activities and VOCs concentration variations are of utmost importance for offering a reliable characterization of risk for dentists and dental staff health. In this study we review the most relevant environmental studies addressing the VOCs contamination level in dental settings. We analyze the methodological problems this kind of study must face and we report preliminary results of an indoor air investigation, carried out at dental hospital in Italy, the "Ospedale odontoiatrico George Eastman" of Rome, in which general lines for the analysis of dental settings in environmental terms are sketched. The aim of this work is to identify the kind of problems a typical enclosed (non-industrial) environment indoor air investigation has to cope with by means of the analysis of a case study.

  16. Organic Contaminant Levels in Three Fish Species Downchannel from the Los Alamos National Laboratory

    SciTech Connect

    Gonzales, G.J.; Fresquez, P.R.; Beveridge, J.W.

    1999-06-01

    The LANL contribution, if any, to organic contaminant levels in the common carp, the channel catfish, and the white sucker in the Rio Grande appear to be small; however, low sample sizes, high variation, and potential interaction of species effect with location treatment effect require additional sampling and analysis.

  17. 40 CFR 142.60 - Variances from the maximum contaminant level for total trihalomethanes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Variances from the maximum contaminant level for total trihalomethanes. 142.60 Section 142.60 Protection of Environment ENVIRONMENTAL... disinfectant or oxidant. (2) Use of chlorine dioxide as an alternate or supplemental disinfectant or...

  18. 40 CFR 142.60 - Variances from the maximum contaminant level for total trihalomethanes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Variances from the maximum contaminant level for total trihalomethanes. 142.60 Section 142.60 Protection of Environment ENVIRONMENTAL... disinfectant or oxidant. (2) Use of chlorine dioxide as an alternate or supplemental disinfectant or...

  19. 40 CFR 142.60 - Variances from the maximum contaminant level for total trihalomethanes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Variances from the maximum contaminant level for total trihalomethanes. 142.60 Section 142.60 Protection of Environment ENVIRONMENTAL... disinfectant or oxidant. (2) Use of chlorine dioxide as an alternate or supplemental disinfectant or...

  20. Vandenberg Air Force Base Upper Level Wind Launch Weather Constraints

    NASA Technical Reports Server (NTRS)

    Shafer, Jaclyn A.; Wheeler, Mark M.

    2012-01-01

    The 30th Operational Support Squadron Weather Flight (30 OSSWF) provides comprehensive weather services to the space program at Vandenberg Air Force Base (VAFB) in California. One of their responsibilities is to monitor upper-level winds to ensure safe launch operations of the Minuteman III ballistic missile. The 30 OSSWF tasked the Applied Meteorology Unit (AMU) to analyze VAFB sounding data with the goal of determining the probability of violating (PoV) their upper-level thresholds for wind speed and shear constraints specific to this launch vehicle, and to develop a tool that will calculate the PoV of each constraint on the day of launch. In order to calculate the probability of exceeding each constraint, the AMU collected and analyzed historical data from VAFB. The historical sounding data were retrieved from the National Oceanic and Atmospheric Administration Earth System Research Laboratory archive for the years 1994-2011 and then stratified into four sub-seasons: January-March, April-June, July-September, and October-December. The maximum wind speed and 1000-ft shear values for each sounding in each subseason were determined. To accurately calculate the PoV, the AMU determined the theoretical distributions that best fit the maximum wind speed and maximum shear datasets. Ultimately it was discovered that the maximum wind speeds follow a Gaussian distribution while the maximum shear values follow a lognormal distribution. These results were applied when calculating the averages and standard deviations needed for the historical and real-time PoV calculations. In addition to the requirements outlined in the original task plan, the AMU also included forecast sounding data from the Rapid Refresh model. This information provides further insight for the launch weather officers (LWOs) when determining if a wind constraint violation will occur over the next few hours on day of launch. The interactive graphical user interface (GUI) for this project was developed in

  1. Ocular surface adverse effects of ambient levels of air pollution.

    PubMed

    Torricelli, André Augusto Miranda; Novaes, Priscila; Matsuda, Monique; Alves, Milton Ruiz; Monteiro, Mário Luiz Ribeiro

    2011-01-01

    It is widely recognized today that outdoor air pollution can affect human health. Various chemical components that are present in ambient pollution may have an irritant effect on the mucous membranes of the body, particularly those of the respiratory tract. Much less attention has been focused on the adverse effect on the ocular surface, despite the fact that this structure is even more exposed to air pollution than the respiratory mucosa since only a very thin tear film separates the corneal and conjunctival epithelia from the air pollutants. So far, clinical data are the more widespread tools used by ophthalmologists for assessing possible aggression to the ocular surface; however, clinical findings alone appears not to correlate properly with the complaints presented by the patients pointing out the need for further clinical and laboratory studies on the subject. The purpose of this study is to review signs and symptoms associated with chronic long-term exposure to environmental air pollutants on the ocular structures currently defined as the ocular surface and to review clinical and laboratory tests used to investigate the adverse effects of air pollutants on such structures. We also review previous studies that investigated the adverse effects of air pollution on the ocular surface and discuss the need for further investigation on the subject.

  2. An objective definition of air mass types affecting Athens, Greece; the corresponding atmospheric pressure patterns and air pollution levels.

    PubMed

    Sindosi, O A; Katsoulis, B D; Bartzokas, A

    2003-08-01

    This work aims at defining characteristic air mass types that dominate in the region of Athens, Greece during the cold (November-March) and the warm (May-September) period of the year and also at evaluating the corresponding concentration levels of the main air pollutants. For each air mass type, the mean atmospheric pressure distribution (composite maps) over Europe and the Mediterranean is estimated in order to reveal the association of atmospheric circulation with air pollution levels in Athens. The data basis for this work consists of daily values of thirteen meteorological and six pollutant parameters covering the period 1993-97. The definition of the characteristic air mass types is attempted objectively by using the methods of Factor Analysis and Cluster Analysis. The results show that during the cold period of the year there are six prevailing air mass types (at least 3% of the total number of days) and six infrequent ones. The examination of the corresponding air pollution concentration levels shows that the primary air pollutants appear with increased concentrations when light or southerly winds prevail. This is usually the case when a high pressure system is located over the central Mediterranean or a low pressure system lays over south Italy, respectively. Low levels of the primary pollutants are recorded under northeasterly winds, mainly caused by a high pressure system over Ukraine. During the warm period of the year, the southwestern Asia thermal low and the subtropical anticyclone of the Atlantic Ocean affect Greece. Though these synoptic systems cause almost stagnant conditions, four main air mass types are dominant and ten others, associated with extreme weather, are infrequent. Despite the large amounts of total solar radiation characterizing this period, ozone concentrations remain at low levels in central Athens because of its destruction by nitric oxide.

  3. Treatment of Perchlorate-Contaminated Groundwater Using Highly-Selective, Regenerable Anion-Exchange Resins at Edwards Air Force Base

    SciTech Connect

    Gu, B.

    2003-05-30

    Selective ion exchange is one of the most effective treatment technologies for removing low levels of perchlorate (ClO{sub 4}{sup -}) from contaminated water because of its high efficiency without adverse impacts on the water quality caused by adding or removing any chemicals or nutrients. This report summarizes both the laboratory and a field pilot-scale studies to determine the ability and efficiency of the bifunctional synthetic resins to remove ClO{sub 4}{sup -} from the contaminated groundwater at the Edwards Air Force Base in California. Regeneration of the resins after groundwater treatment was also evaluated using the FeCl{sub 3}-HCl regeneration technique recently developed at Oak Ridge National Laboratory. On the basis of this study, the bifunctional resin, D-3696 was found to be highly selective toward ClO{sub 4}{sup -} and performed much better than one of the best commercial nitrate-selective resins (Purolite A-520E) and more than an order of magnitude better than the Purolite A-500 resin (with a relatively low selectivity). At an influent concentration of {approx} 450 {micro}g/L ClO{sub 4}{sup -} in groundwater, the bifunctional resin bed treated {approx} 40,000 empty bed volumes of groundwater before a significant breakthrough of ClO{sub 4}{sup -} occurred. The presence of relatively high concentrations of chloride and sulfate in site groundwater did not appear to affect the ability of the bifunctional resin to remove ClO{sub 4}{sup -}. However, the presence of high iron or iron oxyhydroxides and/or biomass in groundwater caused a significant fouling of the resin beds and greatly influenced the effectiveness in regenerating the resins sorbed with ClO{sub 4}{sup -}. Under such circumstances, a prefilter ({approx} 0.5-1 {micro}m) was found to be necessary to remove these particulates and to reduce the risk of fouling of the resin beds. Without significant fouling, the resin bed could be effectively regenerated by the FeCl{sub 3} displacement technique

  4. Contaminant levels in eggs of American white pelicans, Pelecanus erythrorhynchos, from Chase Lake, North Dakota

    USGS Publications Warehouse

    Pietz, Pamela J.; Sovada, Marsha A.; Custer, Christine M.; Custer, Thomas W.; Johnson, Kevin M.

    2008-01-01

    American White Pelicans (Pelecanus erythrorhynchos) are colonial nesters, making them susceptible to site-specific mortality factors. One of the largest known breeding colonies is at Chase Lake National Wildlife Refuge in North Dakota. In 2004, this colony suffered total reproductive failure. In 2005, we collected abandoned eggs from this colony to test for environmental contaminants. Nine eggs were analyzed for 28 organochlorine pesticides, total polychlorinated biphenyls, and 26 inorganic elements. Based on concentrations in this sample of eggs and levels linked to reproductive problems in birds, adult pelicans in the Chase Lake breeding colony are not at known risk from any of the environmental contaminants we measured.

  5. 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.

  6. Influence of air contaminants on planar, self-breathing hydrogen PEM fuel cells in an outdoor environment

    NASA Astrophysics Data System (ADS)

    Biesdorf, Johannes; Zamel, Nada; Kurz, Timo

    2014-02-01

    In this study, the effects of air contaminants on the operation of air-breathing fuel cells in an outdoor environment are investigated. For this purpose, a unique testing platform, which allows continuous operation of 30 cells at different locations, was developed. Three of these testing platforms were placed at different sites in Freiburg im Breisgau, Germany, with high variances of weather and pollution patterns. These locations range from a highly polluted place next to a busy highway to a location with virtually pure air at an altitude of 1205 m. The fuel cells were tested at all sites for over 4500 h in continuous operation. The degradation of the cells due to air pollutants was measured as a voltage decrease for three different operation loads and membranes from two different manufactures. As the temperature of the fuel cells has not been regulated, the irreversible degradation of the cell voltages could not be isolated from the dominant influence of the temperature in the raw data. With the use of the measured data, the impact of real mixtures of air contaminants was observed to be mainly reversible.

  7. Air is still contaminated 40 years after the Michigan Chemical plant disaster in St. Louis, Michigan.

    PubMed

    Peverly, Angela A; Salamova, Amina; Hites, Ronald A

    2014-10-01

    The Michigan Chemical (also known as Velsicol Chemical) plant located in St. Louis, Michigan operated from 1936-1978. During this time, the plant manufactured polybrominated biphenyls (PBBs), hexabromobenzene (HBB), 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT), and tris(2,3-dibromopropyl) phosphate (TDBPP), among other products. Due to widespread PBB contamination of Michigan, the plant eventually became a Superfund site, and despite years of cleanup activities, many of the compounds can still be found in the local ecosystem. To investigate the current atmospheric levels and to determine their spatial distributions, we collected tree bark samples from around Michigan and measured the concentrations of these pollutants. For comparison, other organic pollutants, such as polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs), which were not manufactured at the Michigan Chemical plant, were also measured in the same tree bark samples. Our results show levels of PBBs, DDT, and HBB in tree bark collected within 10 km of the Velsicol Superfund site (43, 477, and 108 ng/g lipid wgt., respectively) are 1-2 orders of magnitude higher than at sites located more than 10 km from the site (0.36, 28, and 0.36 ng/g lipid wgt., respectively). Levels of PBDEs and OPEs did not depend on distance from St. Louis. This is the first study on the atmospheric distribution of these chemicals around the Superfund site. PMID:25211223

  8. Reproductive ecology of tree swallows (Tachycineta bicolor) with high levels of polychlorinated biphenyl contamination

    SciTech Connect

    McCarty, J.P.; Secord, A.L.

    1999-07-01

    Tree swallows(Tachycineta bicolor) breeding along the Hudson River forage extensively on PCB-contaminated insects that emerge from the river. The authors studied the reproductive ecology and behavior of tree swallows breeding at several sites along the Hudson River. Related work has shown that PCB levels in both eggs and chicks were among the highest ever reported in this species, with concentrations comparable to those found in aquatic organisms in the Hudson River. In 1994, reproductive success at PCB-contaminated sites was significantly impaired relative to other sites in New York. Reduced reproductive success was largely due to high levels of nest abandonment during incubation and reduced hatchability of eggs. In 1995, reproductive output was normal, but higher than expected rates of abandonment and supernormal clutches persisted. Growth and development of nestlings was not significantly impaired. Given the levels of contamination in this population, the success of most Hudson River tree swallows reinforces the importance of understanding interspecific differences in the effects of contaminants.

  9. Reproductive and behavioral abnormalities in tree swallows with high levels of PCB contamination

    SciTech Connect

    McCarty, J. |; Secord, A.; Tillitt, D.

    1995-12-31

    Tree Swallows (Tachycineta bicolor) breeding along the Hudson River forage extensively on PCB contaminated insects that emerge from the river. The authors studied the reproductive ecology and behavior of tree swallows breeding at several sites along the Hudson River. These sites vary in the severity of PCB contamination. PCB levels in both eggs and chicks were found to be among the highest ever reported in this species, with concentrations comparable to those found in aquatic organisms in the Hudson River. In 1994 reproductive success at PCB contaminated sites was significantly impaired, relative to other sites in New York. Reduced reproductive success was largely attributed to high levels of nest abandonment during incubation and reduced hatchability of eggs. Growth and development of nestlings was not significantly impaired. Abnormal nest building behavior was also noted in 1994, and this was studied in detail in 1995. Nests from contaminated areas are significantly smaller than those at a nearby reference site and at other sites in New York. The authors suggest that the reduced reproductive outputs at these sites are, in large part, a result of effects on the behavior of incubating females. The population-level implications of these patterns are unknown.

  10. Particulate Matter Levels in Ambient Air Adjacent to Industrial Area

    NASA Astrophysics Data System (ADS)

    Mohamed, R. M. S. R.; Nizam, N. M. S.; Al-Gheethi, A. A.; Lajis, A.; Kassim, A. H. M.

    2016-07-01

    Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with human health risks. In this work, the concentrations of particulate matter (PM10) in the ambient air of UTHM campus was investigated tostudy the air qualityand their compliance to the Malaysian Ambient Air Quality Guidelines (AAQG). The PM10 samples were taken over 24 hours from the most significant area at UTHM including Stadium, KolejKediamanTunDr. Ismail (KKTDI) and MakmalBahan. The meteorological parameters; temperature, relative humidity, wind speed and wind direction as well as particulate matterwere estimated by using E-Sampler Particulate Matter (PM10) Collector. The highest concentrations of PM10 (55.56 µg/m3) was recorded at MakmalBahan during the working and weekend days. However, these concentrations are less than 150 pg/m3. It can be concluded that although UTHM is surrounded by the industrial area, the air quality in the campus still within the standards limits.

  11. Contamination of aluminium oxide surfaces in ambient air investigated by FTIR MSR and TOF SIMS. Chemisorption of aliphatic carboxylic acids

    NASA Astrophysics Data System (ADS)

    Sondag, A. H. M.; Raas, M. C.; Van Velzen, P. N. T.

    1989-03-01

    Contamination in ambient air of freshly evaporated aluminium surfaces covered with a thin layer of native oxide has been studied using Fourier transform infrared multiple specular reflectance (FTIR MSR) and time-of-flight secondary ion mass spectrometry (TOF SIMS). The FTIR MSR experiments yield vibrational spectra than can be attributed to short-chain aliphatic carboxylic acids. Some reference spectra have been measured by FTIR MSR spectroscopy of samples prepared by chemisorption of formic, acetic, lactic, butyric and palmitic acids on oxidized aluminium and (in some cases) silver surfaces. From these data the major contaminant has to be the acetate ion. Saturation of the spectral intensities is observed within an hour after exposure to air. The TOF SIMS spectra confirm the conclusion with respect to the acetate ion. Mass peaks belonging to the formate, lactate and some inorganic anions are present in the TOF SIMS spectra.

  12. High dermatophyte contamination levels in hairdressing salons of a West African suburban community.

    PubMed

    Coulibaly, O; Thera, M A; Piarroux, R; Doumbo, O K; Ranque, S

    2015-02-01

    Tinea capitis is a dermatophyte infection of scalp is commonly spread by currently infected patients, asymptomatic carriers or by fomites, such as hairdressing tools. However, studies on the risk factors of Tinea capitis remain scarce. The aim of this study was to evaluate the dermatophytes contamination level of the hairdressing tools to which hairdressing salon customers are exposed in Sirakoro-Méguétana, a suburb of Bamako, the capital city of Mali. A total of 41 hairdressing tools were sampled in five hairdressing salons. Two anthropophilic dermatophytes species, Microsporum audouinii (53.3%) and Trichophyton soudanense (46.7%), were cultured from 30 (73.2%) samples. This first study, addressing hairdressing salons dermatophyte contamination, revealed a strikingly high contamination of hairdressing tools with dermatophyte propagules, which exposes hairdressing salons customers to an important dermatophytosis risk. The sterilisation of hairdressing tools is central to preventing dermatophytoses spreading. Appropriate community information and hairdressers training should be implemented in this view.

  13. [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.

  14. Integration of photocatalytic oxidation with air stripping of contaminated aquifers. Report for 1 October 1993--30 June 1997

    SciTech Connect

    Changrani, R.; Raupp, G.B.; Turchi, C.

    1998-12-01

    The global objective of this work was to evaluate the integration of gas-solid ultraviolet (UV) photocatalytic oxidation (PCO) downstream of an air stripper as a technology for cost-effectively treating water pumped from an aquifer contaminated with chlorinated volatile organic compounds (VOCs). Experimental work was performed at the bench-scale in the laboratory during the first phase of the project, and at the pilot-scale in a simulated field-test situation during the second phase.

  15. Changes in contaminant levels in New Jersey osprey eggs and prey, 1989 to 1998.

    PubMed

    Clark, K E; Stansley, W; Niles, L J

    2001-02-01

    Ospreys are good indicators of the health of estuarine areas because they feed almost exclusively on fish with the balance on other aquatic biota. Through the 1980s, ospreys nesting on Delaware Bay in New Jersey had reduced reproductive success relative to those nesting on the Atlantic coast and the Maurice River, a tributary of Delaware Bay. Earlier research suggested that elevated levels of DDT and polychlorinated biphenyl (PCB) contaminants identified in addled osprey eggs contributed to this reduced productivity. We repeated egg and prey sampling initially conducted in 1989 to evaluate the trends of contaminants in the last decade. Most organochlorine contaminants declined in osprey eggs in 1998 relative to 1989. Across three study areas, PCBs decreased from 4.1-7.7 ppm in 1989 to 1.8-3.2 ppm in 1998; DDE decreased from 1.2-3.2 ppm in 1989 to 0.7-1.2 ppm in 1998. Lead in eggs increased from an average of 0.01 to 0.30 ppm wet weight, and mercury averaged 0.12 ppm and increased only in Atlantic coast eggs. Most of these contaminant changes were also found in typical prey fish: PCBs decreased from 0.18-1.2 ppm in 1989 to 0.06-0.43 ppm in 1998; DDE decreased from 0.05-0.69 ppm in 1989 to 0.03-0.13 ppm in 1998. Lead and mercury increased in most fish samples. The improvement in most organochlorine contaminants in osprey eggs and prey reflected improved nest success in the Delaware Bay study area, and the nesting populations in the Atlantic and Maurice River study areas increased approximately 200% since 1989. PCBs and DDE in osprey eggs were below levels considered to be toxic to egg development. This study documents significant improvements in organochlorine contaminants in southern New Jersey ospreys, but justifies continued monitoring of heavy metals, such as lead and mercury, in aquatic ecosystems. PMID:11243331

  16. Probabilistic approach to estimating indoor air concentrations of chlorinated volatile organic compounds from contaminated groundwater: a case study in San Antonio, Texas.

    PubMed

    Johnston, Jill E; Gibson, Jacqueline MacDonald

    2011-02-01

    This paper describes a probabilistic model, based on the Johnson-Ettinger algorithm, developed to characterize the current and historic exposure to tricholorethylene (TCE) and tetrachlorethylene (PCE) in indoor air from plumes of groundwater contamination emanating from the former Kelly Air Force Base in San Antonio, Texas. We estimate indoor air concentration, house by house, in 30 101 homes and compare the estimated concentrations with measured values in a small subset of homes. We also compare two versions of the Johnson-Ettinger model: one used by the Environmental Protection Agency (EPA) and another based on an alternative parametrization. The modeled mean predicted PCE concentration historically exceeded PCE screening levels (0.41 ug/m(3)) in 5.5% of houses, and the 95th percentile of the predicted concentration exceeded screening levels in 85.3% of houses. For TCE, the mean concentration exceeded the screening level (0.25 ug/m(3)) in 49% of homes, and the 95th percentile of the predicted concentration exceeded the screening level in 99% of homes. The EPA model predicts slightly lower indoor concentrations than the alternative parametrization. Comparison with measured samples suggests both models, with the inputs selected, underestimate indoor concentrations and that the 95th percentiles of the predicted concentrations are closer to measured concentrations than predicted mean values.

  17. Procedures for addressing uncertainty and variability in exposure to characterize potential health risk from trichloroethylene contaminated groundwater at Beale Air Force Base in California

    SciTech Connect

    Bogen, K T; Daniels, J I; Hall, L C

    1999-09-01

    This study was designed to accomplish two objectives. The first was to provide to the US Air Force and the regulatory community quantitative procedures that they might want to consider using for addressing uncertainty and variability in exposure to better characterize potential health risk. Such methods could be used at sites where populations may now or in the future be faced with using groundwater contaminated with low concentrations of the chemical trichloroethylene (TCE). The second was to illustrate and explain the application of these procedures with respect to available data for TCE in ground water beneath an inactive landfill site that is undergoing remediation at Beale Air Force Base in California. The results from this illustration provide more detail than the more traditional conservative deterministic, screening-level calculations of risk, also computed for purposes of comparison. Application of the procedures described in this report can lead to more reasonable and equitable risk-acceptability criteria for potentially exposed populations at specific sites.

  18. CAirTOX, An inter-media transfer model for assessing indirect exposures to hazardous air contaminants

    SciTech Connect

    McKone, T.E.

    1994-01-01

    Risk assessment is a quantitative evaluation of information on potential health hazards of environmental contaminants and the extent of human exposure to these contaminants. As applied to toxic chemical emissions to air, risk assessment involves four interrelated steps. These are (1) determination of source concentrations or emission characteristics, (2) exposure assessment, (3) toxicity assessment, and (4) risk characterization. These steps can be carried out with assistance from analytical models in order to estimate the potential risk associated with existing and future releases. CAirTOX has been developed as a spreadsheet model to assist in making these types of calculations. CAirTOX follows an approach that has been incorporated into the CalTOX model, which was developed for the California Department of Toxic Substances Control, With CAirTOX, we can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The capacity to explicitly address uncertainty has been incorporated into the model in two ways. First, the spreadsheet form of the model makes it compatible with Monte-Carlo add-on programs that are available for uncertainty analysis. Second, all model inputs are specified in terms of an arithmetic mean and coefficient of variation so that uncertainty analyses can be carried out.

  19. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  20. Making leaps in amphibian ecotoxicology: translating individual-level effects of contaminants to population viability.

    PubMed

    Willson, J D; Hopkins, W A; Bergeron, C M; Todd, B D

    2012-09-01

    Concern that environmental contaminants contribute to global amphibian population declines has prompted extensive experimental investigation, but individual-level experimental results have seldom been translated to population-level processes. We used our research on the effects of mercury (Hg) on American toads (Bufo americanus) as a model for bridging the gap between individual-level contaminant effects and amphibian population viability. We synthesized the results of previous field and laboratory studies examining effects of Hg throughout the life cycle of B. americanus and constructed a comprehensive demographic population model to evaluate the consequences of Hg exposure on population dynamics. Our model explicitly considered density-dependent larval survival, which is known to be an important driver of amphibian population dynamics, and incorporated two important factors that have seldom been considered in previous amphibian modeling studies: environmental stochasticity and sublethal effects. We demonstrated that decreases in embryonic survival and sublethal effects (e.g., reduced body size) that delay maturation have minor effects on population dynamics, whereas contaminant effects that reduce late-larval or post-metamorphic survival have important population-level consequences. We found that excessive Hg exposure through maternal transfer or larval diet, alone, had minor effects on B. americanus populations. Simultaneous maternal and dietary exposure resulted in reduced population size and a dramatic increase in extinction probability, but explicit prediction of population-level effects was dependent on the strength of larval density dependence. Our results suggest that environmental contaminants can influence amphibian population viability, but that highly integrative approaches are needed to translate individual-level effects to populations.

  1. MEASUREMENT OF LOW LEVEL AIR TOXICS WITH MODIFIED UV DOAS

    EPA Science Inventory

    To further understand near source impacts, EPA is working to develop open-path optical techniques for spatiotemporal-resolved measurement of air pollutants. Of particular interest is near real time quantification of mobile-source generated CO, Nox and hydrocarbons measured in cl...

  2. Prevention of optics and resist contamination in 300-mm lithography: improvements in chemical air filtration

    NASA Astrophysics Data System (ADS)

    Kinkead, Devon A.; Grayfer, Anatoly; Kishkovich, Oleg P.

    2001-08-01

    Atmospheric pressure deep UV lithography using fast chemically amplified photoresists will be the mainstay of semiconductor production into the foreseeable future. Airborne molecular contamination (AMC) in the form of bases and condensable organic and inorganic materials however, threaten both sensitive optics and modern resists thereby creating a host of yield limiting contamination issues. Past work by Kunz at MIT has described photo-induced organic contamination of lithographic optics as a significant concern in leading-edge lithography. Moreover, Kinkead and Ercken, and Kishkovich and Dean have published work on the impact of base contamination on CD uniformity in modern photoresists. Herein, the authors discuss solutions to control both optics and resist contamination in a single compact filter system for advanced lithography. The results of this work suggest that resist and optics contamination can be controlled as we enter the era of low K1 factor <150nm/300mm-device production.

  3. Campylobacter jejuni contamination of broiler carcasses: Population dynamics and genetic profiles at slaughterhouse level.

    PubMed

    Gruntar, Igor; Biasizzo, Majda; Kušar, Darja; Pate, Mateja; Ocepek, Matjaž

    2015-09-01

    Six slaughter batches deriving from six typical industrial broiler flocks were examined for the presence, quantity and genetic characteristics of contaminating Campylobacter jejuni (C. jejuni) during various stages of slaughtering and carcass processing. To assess the contamination dynamics of the carcasses, the analyses were always conducted on neck-skin samples from the same pre-selected and carefully marked carcasses in each batch. The skin samples were taken sequentially at three successive slaughter-line locations in the evisceration room, after three-day refrigeration and after three-day freezing procedure. Caecal samples from the same animals were also tested, as well as samples from the slaughterhouse environment before and after slaughtering. The samples were analysed by the ISO10272 isolation method; campylobacters from neck-skin samples were also quantified. Isolates were species-identified and genotyped by pulsed-field gel electrophoresis (PFGE). On average, the highest C. jejuni skin contamination was detected at the first sampling point (post-plucking), suggesting that the majority of Campylobacter contamination actually occurs before the entrance to the eviscerating room, probably during the preceding plucking stage. In two out of five positive batches, an additional increase in contamination was recorded after the evisceration step. An evident trend of increasing contamination level was detected when successive batches were compared at each of two initial sampling sites in the evisceration room, indicating an accumulation of contaminating C. jejuni at some point before the evisceration room. Three-day refrigeration and three-day freezing caused a 4.5- and 142-fold drop in mean C. jejuni CFU counts, respectively. All pre-slaughtering samples from the slaughterhouse environment were negative and all post-slaughtering samples, except water from the scalding tank, were positive. Pulsotypes were limited: altogether five different types were detected

  4. Campylobacter jejuni contamination of broiler carcasses: Population dynamics and genetic profiles at slaughterhouse level.

    PubMed

    Gruntar, Igor; Biasizzo, Majda; Kušar, Darja; Pate, Mateja; Ocepek, Matjaž

    2015-09-01

    Six slaughter batches deriving from six typical industrial broiler flocks were examined for the presence, quantity and genetic characteristics of contaminating Campylobacter jejuni (C. jejuni) during various stages of slaughtering and carcass processing. To assess the contamination dynamics of the carcasses, the analyses were always conducted on neck-skin samples from the same pre-selected and carefully marked carcasses in each batch. The skin samples were taken sequentially at three successive slaughter-line locations in the evisceration room, after three-day refrigeration and after three-day freezing procedure. Caecal samples from the same animals were also tested, as well as samples from the slaughterhouse environment before and after slaughtering. The samples were analysed by the ISO10272 isolation method; campylobacters from neck-skin samples were also quantified. Isolates were species-identified and genotyped by pulsed-field gel electrophoresis (PFGE). On average, the highest C. jejuni skin contamination was detected at the first sampling point (post-plucking), suggesting that the majority of Campylobacter contamination actually occurs before the entrance to the eviscerating room, probably during the preceding plucking stage. In two out of five positive batches, an additional increase in contamination was recorded after the evisceration step. An evident trend of increasing contamination level was detected when successive batches were compared at each of two initial sampling sites in the evisceration room, indicating an accumulation of contaminating C. jejuni at some point before the evisceration room. Three-day refrigeration and three-day freezing caused a 4.5- and 142-fold drop in mean C. jejuni CFU counts, respectively. All pre-slaughtering samples from the slaughterhouse environment were negative and all post-slaughtering samples, except water from the scalding tank, were positive. Pulsotypes were limited: altogether five different types were detected

  5. 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.

  6. Microbiological analysis of multi-level borehole samples from a contaminated groundwater system

    NASA Astrophysics Data System (ADS)

    Pickup, R. W.; Rhodes, G.; Alamillo, M. L.; Mallinson, H. E. H.; Thornton, S. F.; Lerner, D. N.

    2001-12-01

    A range of bacteriological, geochemical process-related and molecular techniques have been used to assess the microbial biodegradative potential in groundwater contaminated with phenol and other tar acids. The contaminant plume has travelled 500 m from the pollutant source over several decades. Samples were obtained from the plume using a multi-level sampler (MLS) positioned in two boreholes (boreholes 59 and 60) which vertically transected two areas of the plume. Activity of the microbial community, as represented by phenol degradation potential and ability to utilise a range of substrates, was found to be influenced by the plume. Phenol degradation potential appeared to be influenced more by the concentration of the contaminants than the total bacterial cell numbers. However, in the areas of highest phenol concentration, the depression of cell numbers clearly had an effect. The types of bacteria present were assessed by culture and DNA amplification by polymerase chain reaction (PCR). Bacterial groups or processes associated with major geochemical processes, such as methanogenesis, sulphate reduction and denitrification, that have the potential to drive contaminant degradation, were detected at various borehole levels. A comparative molecular analysis of the microbial community between samples obtained from the MLS revealed the microbial community was diverse. The examination of microbial activity complemented those results obtained through chemical analysis, and when combined with hydrological data, showed that MLS samples provided a realistic profile of plume effects and could be related to the potential for natural attenuation of the site.

  7. Identification of risk factors for Campylobacter contamination levels on broiler carcasses during the slaughter process.

    PubMed

    Seliwiorstow, Tomasz; Baré, Julie; Berkvens, Dirk; Van Damme, Inge; Uyttendaele, Mieke; De Zutter, Lieven

    2016-06-01

    Campylobacter carcass contamination was quantified across the slaughter line during processing of Campylobacter positive batches. These quantitative data were combined together with information describing slaughterhouse and batch related characteristics in order to identify risk factors for Campylobacter contamination levels on broiler carcasses. The results revealed that Campylobacter counts are influenced by the contamination of incoming birds (both the initial external carcass contamination and the colonization level of caeca) and the duration of transport and holding time that can be linked with feed withdrawal period. In addition, technical aspects of the slaughter process such as a dump based unloading system, electrical stunning, lower scalding temperature, incorrect setting of plucking, vent cutter and evisceration machines were identified as risk factors associated with increased Campylobacter counts on processed carcasses. As such the study indicates possible improvements of the slaughter process that can result in better control of Campylobacter numbers under routine processing of Campylobacter positive batches without use of chemical or physical decontamination. Moreover, all investigated factors were existing variations of the routine processing practises and therefore proposed interventions are practically and economically achievable.

  8. Response of the microbial community to seasonal groundwater level fluctuations in petroleum hydrocarbon-contaminated groundwater.

    PubMed

    Zhou, Ai-xia; Zhang, Yu-ling; Dong, Tian-zi; Lin, Xue-yu; Su, Xiao-si

    2015-07-01

    The effects of seasonal groundwater level fluctuations on the contamination characteristics of total petroleum hydrocarbons (TPH) in soils, groundwater, and the microbial community were investigated at a typical petrochemical site in northern China. The measurements of groundwater and soil at different depths showed that significant TPH residue was present in the soil in this study area, especially in the vicinity of the pollution source, where TPH concentrations were up to 2600 mg kg(-1). The TPH concentration in the groundwater fluctuated seasonally, and the maximum variation was 0.8 mg L(-1). The highest TPH concentrations were detected in the silty clay layer and lied in the groundwater level fluctuation zones. The groundwater could reach previously contaminated areas in the soil, leading to higher groundwater TPH concentrations as TPH leaches into the groundwater. The coincident variation of the electron acceptors and TPH concentration with groundwater-table fluctuations affected the microbial communities in groundwater. The microbial community structure was significantly different between the wet and dry seasons. The canonical correspondence analysis (CCA) results showed that in the wet season, TPH, NO3(-), Fe(2+), TMn, S(2-), and HCO3(-) were the major factors correlating the microbial community. A significant increase in abundance of operational taxonomic unit J1 (97% similar to Dechloromonas aromatica sp.) was also observed in wet season conditions, indicating an intense denitrifying activity in the wet season environment. In the dry season, due to weak groundwater level fluctuations and low temperature of groundwater, the microbial activity was weak. But iron and sulfate-reducing were also detected in dry season at this site. As a whole, groundwater-table fluctuations would affect the distribution, transport, and biodegradation of the contaminants. These results may be valuable for the control and remediation of soil and groundwater pollution at this site

  9. Simulation of ground-water flow and potential contaminant transport at Area 6 Landfill, Naval Air Station Whidbey Island, Island County, Washington

    USGS Publications Warehouse

    Simonds, F. William

    2002-01-01

    A three-dimensional finite-difference steady-state ground-water flow model was developed to simulate hydraulic conditions at the Area 6 Landfill, Naval Air Station Whidbey Island, near Oak Harbor, Washington. Remediation efforts were started in 1995 in an attempt to contain trichloroethene and other contaminants in the ground water. The model was developed as a tool to test the effectiveness of the pump-and-treat remediation efforts as well as alternative remediation strategies. The model utilized stratigraphic data from approximately 76 Navy and 19 private wells to define the geometry of the shallow, intermediate, and deep aquifers and the intervening confining layers. Initial aquifer parameters and recharge estimates from aquifer tests and published remedial investigation reports were used in the model and then adjusted until simulated water levels closely matched observed water-level data collected prior to the onset of remediation in 1995. The calibrated model was then modified to depict the remedial pump-and-treat system, in which contaminated ground water is extracted, treated, and returned to the ground surface for infiltration. The water levels simulated by the modified model were compared with observed water levels for the 1998 calendar year, during which time the pump-and-treat system was in nearly continuous operation and the ground-water system had equilibrated to steady-state conditions. Although artificial boundaries were used in the model, the choice of model boundary conditions was simulation in the area of primary concern surrounding the western contaminant plume and extraction wells. Particle tracking results indicate that the model can effectively simulate the advective transport of contaminants from the source area to the pumping wells and thus be used to test alternative remedial pumping strategies.

  10. Enzymatic GST levels and overall health of mullets from contaminated Brazilian Lagoons.

    PubMed

    Bastos, F F; Hauser-Davis, R A; Tobar, S A L; Campos, R C; Ziolli, R L; Bastos, V L F Cunha; Bastos, J Cunha

    2013-01-15

    Glutathione S-transferase (GST) assays in non-mammalian organisms are usually conducted inappropriately, since no previous standardization of the optimal concentrations of proteins and substrates and adequate pH is conducted. Standardization is a key task to adjust enzyme assays at their kinetically correct maximal initial velocities, if one wants these velocities to indicate the amount of enzyme in a sample. In this paper GST assays were standardized in liver cytosol to compare seasonal GST levels in liver of mullet from two contaminated lagoons in the Rio de Janeiro to those from a reference bay. GST potential as a biomarker of sublethal intoxication in this species was also evaluated. Mullet liver GST levels assayed with substrates that corresponded to three different GST isoenzymes varied throughout the year. The differences indicated that mullets are suffering from sublethal intoxication from contaminants in these lagoons. Seasonal variations of activity were relevant, since these could indicate differences in xenobiotic input into the areas. An analysis of overall mullet health condition using a morphological index (the Fulton Condition Factor) and macroscopic abnormalities corroborated the differences in GST levels, with fish from one of the sites in worse overall health condition showing lower and significantly different FCF when compared to the reference site. Therefore, GST standardized activity levels are useful biomarkers of environmental contamination for mullet.

  11. Lead-contaminated house dust and urban children's blood lead levels.

    PubMed Central

    Lanphear, B P; Weitzman, M; Winter, N L; Eberly, S; Yakir, B; Tanner, M; Emond, M; Matte, T D

    1996-01-01

    OBJECTIVES: This study assessed the relationship between lead-contaminated house dust and urban children's blood lead levels. METHODS: A random-sample survey was used to identify and enroll 205 children, 12 to 31 months of age, who had resided in the same house since at least 6 months of age. Children's blood and household dust, water, soil, and paint were analyzed for lead, and interviews were conducted to ascertain risk factors for elevated blood lead (> or = 10 micrograms/dL). RESULTS: Children's mean blood lead level was 7.7 micrograms/dL. In addition to dust lead loading (micrograms of lead per square foot), independent predictors of children's blood lead were Black race, soil lead levels, ingestion of soil or dirt, lead content and condition of painted surfaces, and water lead levels. For dust lead standards of 5 micrograms/sq ft, 20 micrograms/sq ft, and 40 micrograms/sq ft on noncarpeted floors, the estimated percentages of children having blood lead levels at or above 10 micrograms/dL were 4%, 15%, and 20%, respectively, after adjusting for other significant covariates. CONCLUSIONS: Lead-contaminated house dust is a significant contributor to lead intake among urban children who have low-level elevations in blood lead. A substantial proportion of children may have blood lead levels of at least 10 micrograms/dL at dust lead levels considerably lower than current standards. PMID:8876511

  12. Dietary intakes and plasma organochlorine contaminant levels among Great Lakes fish eaters.

    PubMed

    Cole, Donald C; Sheeshka, Judy; Murkin, Elaine J; Kearney, Jill; Scott, Fran; Ferron, Lilliane A; Weber, Jean-Phillippe

    2002-01-01

    Nutritional intakes and contaminant burdens should be assessed jointly in individuals who are at high risk of environmental exposures to contaminants through food. In this study, the authors used shore surveys and community contacts to recruit 91 individuals who frequently consumed Great Lakes fish. These individuals provided dietary intake information and fasting blood samples for lipid and contaminant analyses. Participants ate an annual median of 88 meals of Great Lakes fish. Asian-Canadians consumed more total fish meals (i.e., Great Lakes, non-Great Lakes, and other) (medians = 213.0 females, 223.0 males) than Euro-Canadians (medians = 131.0 females, 137.5 males). The higher total fish consumption by Asian-Canadians was associated with a lower percentage of energy derived from fat, higher protein and iron intakes, and higher plasma concentrations of omega-3 essential fatty acids (e.g., median docosahexaenoic acid levels [microgram/l] in Asian-Canadian females = 5.48, males = 4.38; in Euro-Canadian females = 2.93, males = 2.27). Plasma organochlorine contaminant lipid weight concentrations varied by country of origin and by gender (e.g., median total polychlorinated biphenyls [microgram/kg] in Asian-Canadian females = 490.6, males = 729.0; in Euro-Canadian females = 339.6, males = 355.5). Age was the most consistent predictor (+ve) of contaminant concentrations, followed by years spent in Canada (for Asian-Canadians). Associations with sport fish consumption variables were less consistent than for the aforementioned predictors. Given both the health benefits and potential risks of fish consumption, policies that address diverse ethnocultural groups should support continued consumption of sport fish, but from less-contaminated sources than are currently used.

  13. [Air contamination in the Autonomous City of Buenos Aires: the current risk or future climate change, a false option].

    PubMed

    Abrutzky, Rosana; Dawidowski, Laura; Murgida, Ana; Natenzon, Claudia Eleonor

    2014-09-01

    Based on the theoretical framework of environmental risk, this article discusses the management of air quality in the Autonomous City of Buenos Aires in relation to current and potential impacts of toxic gases and global climate change on the health of the population. Information on historical and current management of the air was linked to the results of the South American Emissions, Megacities and Climate research project to assess danger, exposure, vulnerability and uncertainty as the dimensions of risk. By contextualizing public policies developed in recent decades on this subject, it was possible to identify emerging configurations of risk and uncertainties as accelerators of social vulnerability. On the one hand, the fact that there is a positive correlation between mortality, changes in temperature and air pollution was confirmed. On the other hand, it became clear that there is a disconnect between air quality management and health care management, while limitations were found in the proposed mitigation measures relating to emissions of greenhouse gases produced by fuel, revealing uncertainties regarding their efficacy.

  14. Nitric Oxide and Oxygen Air-Contamination Effects on Extinction Limits of Non-Premixed Hydrocarbon-Air Flames for a HIFiRE Scramjet

    NASA Technical Reports Server (NTRS)

    Pellett, Gerald L.; Dawson, Lucy C.; Vaden, Sarah N.; Wilson, Lloyd G.

    2009-01-01

    Unique nitric oxide (NO) and oxygen air-contamination effects on the extinction Flame Strength (FS) of non-premixed hydrocarbon (HC) vs. air flames are characterized for 7 gaseous HCs, using a new idealized 9.3 mm straight-tube Opposed Jet Burner (OJB) at 1 atm. FS represents a laminar strain-induced extinction limit based on cross-section-average air jet velocity, Uair, that sustains combustion of a counter jet of gaseous fuel just before extinction. Besides ethane, propane, butane, and propylene, the HCs include ethylene, methane, and a 64 mole-% ethylene / 36 % methane mixture, the writer s previously recommended gaseous surrogate fuel for HIFiRE scramjet tests. The HC vs. clean air part of the work is an extension of a May 2008 JANNAF paper that characterized surrogates for the HIFiRE project that should mimic the flameholding of reformed (thermally- or catalytically-cracked) endothermic JP-like fuels. The new FS data for 7 HCs vs. clean air are thus consolidated with the previously validated data, normalized to absolute (local) axial-input strain rates, and co-plotted on a dual kinetically dominated reactivity scale. Excellent agreement with the prior data is obtained for all 7 fuels. Detailed comparisons are also made with recently published (Univ. Va) numerical results for ethylene extinction. A 2009-revised ethylene kinetic model (Univ. Southern Cal) led to predicted limits within approx. 5 % (compared to 45 %, earlier) of this writer s 2008 (and present) ethylene FSs, and also with recent independent data (Univ. Va) obtained on a new OJB system. These +/- 5 % agreements, and a hoped-for "near-identically-performing" reduced kinetics model, would greatly enhance the capability for accurate numerical simulations of surrogate HC flameholding in scramjets. The measured air-contamination effects on normalized FS extinction limits are projected to assess ongoing Arc-Heater-induced "facility test effects" of NO production (e.g., 3 mole-%) and resultant oxygen

  15. Effects of organochlorine contaminants on thyroid hormone levels in Arctic breeding glaucous gulls, Larus hyperboreus.

    PubMed Central

    Verreault, Jonathan; Skaare, Janneche Utne; Jenssen, Bjørn Munro; Gabrielsen, Geir Wing

    2004-01-01

    Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high blood levels of halogenated organic contaminants in this species might cause reproductive, behavioral, and developmental stress. However, potential endocrine system modulation caused by contaminant exposure has yet not been reported in this Arctic apical predator. In this present study we aimed to investigate whether the current levels of a selection of organochlorines (OCs) were associated with altered circulating levels of thyroid hormones (THs) in free-ranging adult glaucous gulls breeding at Bear Island in the Barents Sea. Blood concentrations of 14 polychlorinated biphenyls, hexachlorobenzene (HCB), oxychlordane, and p,p' -dichlorodiphenyldichloroethylene (p,p' -DDE) were quantified, in addition to free and total thyroxine (T4) and triiodothyronine (T3), in plasma of 66 glaucous gulls in the spring of 2001. Negative correlations were found between plasma levels of T4 and T4:T3 ratio, and blood levels of OCs in male glaucous gulls. Despite their relatively low contribution to the total OC fraction, HCB and oxychlordane were the most prominent compounds in terms of their negative effect on the variation of the T4:T3 ratio. Moreover, lower T4 levels and T4:T3 ratios were measured in glaucous gulls breeding in a colony exposed to high levels of OCs, compared with a less exposed colony. Levels of T3 were elevated in the high-OC-exposed colony. This may indicate that the glaucous gull is susceptible to changes to TH homeostasis mediated by exposure to halogenated organic contaminants. PMID:15064156

  16. 14 CFR 325.10 - Modification of the designated level of essential air service.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Modification of the designated level of essential air service. 325.10 Section 325.10 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) PROCEDURAL REGULATIONS ESSENTIAL AIR SERVICE PROCEDURES § 325.10 Modification of the designated level...

  17. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and...

  18. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and...

  19. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and...

  20. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and...

  1. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and...

  2. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and...

  3. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and...

  4. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and...

  5. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and...

  6. 42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.202 Section 84.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and...

  7. Bioavailability of caesium-137 from chernozem soils with high and low levels of radioactive contamination

    NASA Astrophysics Data System (ADS)

    Paramonova, Tatiana; Shamshurina, Eugenia; Machaeva, Ekaterina; Belyaev, Vladimir

    2014-05-01

    Bioavailability of Cs-137 in "soil-plant" system of radioactively contaminated terrestrial ecosystems is the most important factor in the understanding of ecological situation. There are many factors affecting the features of Cs-137 biogeochemical cycle: period since an accident, type and intensity of radioactive fallout, general properties of landscape and the specifics of soil and plant covers, etc. In order to evaluate the importance of soil contamination level for the process of Cs-137 translocation from soil to plant the research in forest-steppe areas of Russia with similar natural properties, but contrasting high (Tula region) and low (Kursk region) levels of radioactive Chernobyl fallout (about 25 years after accident) was conducted. Soil cover of both sites is presented by chernozems with bulk density 1.1-1.2 g/cm3, 6-7% humus and neutral pH 6.5-7.2; plant cover under investigation consist of dry and wet meadows with bioproductivity 1.6-2.5 kg/m2 and 85-90% of biomass concentrated underground, that is typical for Russian forest-steppe landscapes. At the same time levels of soil regional contamination with Cs-137 differ by an order - 620-710 Bq/kg (210-250 kBq/m2) in Tula region and 30-55 Bq/kg (10-20 kBq/m2) in Kursk region. At a higher level of soil radioactive contamination specific activity of Cs-137 in vegetation of meadows is noticeably increased (103-160 Bq/kg in Tula region versus 12-14 Bq/kg in Kursk region) with correlation coefficient r 0.87. Increasing of Cs-137 in the underground parts of plants plays a decisive role in this process, while the specific radionuclide's activity in the aboveground parts of different sites is almost invariant (and ubiquitously roots contain 2-5 times more Cs-137 than shoots). The values of transfer factors for Cs-137 (the ratio of the specific Cs-137 activities in the plant tissue and in the soil) at various levels of soil radioactive contamination vary within a relatively narrow range 0.1-0.4, that confirms the

  8. RELATIONSHIPS BETWEEN LEVELS OF VOLATILE ORGANIC COMPOUNDS IN AIR AND BLOOD FROM THE GENERAL POPULATION

    EPA Science Inventory

    Background: The relationships between levels of volatile organic compounds (VOCs) in blood and air have not been well characterized in the general population where exposure concentrations are generally at ppb levels. Objectives: This study investigates relationships between ...

  9. High-Level Waste Tanks Multi-Dimensional Contaminant Transport Model Development Enhancements for 2000

    SciTech Connect

    Collard, L.B.

    2001-09-21

    A suite of multi-dimensional computer models was developed in 1999 (Collard and Flach) to analyze the transport of residual contamination from high-level waste tanks through the subsurface to seeplines. Enhancements in 2000 to those models include investigate the effect of numerical dispersion, develop a solubility-limited case for U and Pu, and develop a plan for a database as part of the Rapid Screening Tool and start to implement that plan.

  10. Healthy Zero Energy Buildings (HZEB) Program - Cross-Sectional Study of Contaminant Levels, Source, Strengths, and Ventilation Rates in Retail Stores

    SciTech Connect

    Chan, Wanyu R.; Sidheswaran, Meera; Cohn, Sebastian; Sullivan, Douglas P.; Fisk, William

    2014-02-01

    then used to determine the ventilation rates, filtration strategies, or source reductions needed to maintain indoor contaminant concentrations below reference levels. Several scenarios of potential concern were considered: (i) formaldehyde levels in furniture/hardware stores, (ii) contaminants associated with cooking (e.g., PM, acrolein, and acetaldehyde) in grocery stores, and (iii) outdoor contaminants (e.g., PM and O{sub 3}) impacting stores that use natural ventilation. Estimated formaldehyde emission rates suggest that retail stores would need to ventilate at levels far exceeding the current Title 24 requirement to lower indoor concentrations below California’s stringent formaldehyde reference level. Given the high costs of providing ventilation but only modest chronic health benefit is expected, effective source control is an attractive alternative, as demonstrated by some retail stores in this study. Predictions showed that grocery stores need MERV 13 air filters, instead of MERV 8 filters that are more commonly used, to maintain indoor PM at levels that meet the chronic health standards for PM. Exposure to acrolein is a potential health concern in grocery stores, and should be addressed by increasing the use of kitchen range hoods or improving their contaminant removal efficiency. In stores that rely on natural ventilation, indoor PM can be a health concern if the stores are located in areas with high outdoor PM. This concern may be addressed by switching to mechanical ventilation when the outdoor air quality is poor, while continuing natural ventilation when outdoor air quality is good.

  11. Mercury contamination in vicinity of secondary copper smelters in Fuyang, Zhejiang Province, China: levels and contamination in topsoils.

    PubMed

    Yin, Xuebin; Yao, Chunxia; Song, Jing; Li, Zhibo; Zhang, Changbo; Qian, Wei; Bi, De; Li, Chenxi; Teng, Ying; Wu, Longhua; Wan, Hongdong; Luo, Yongming

    2009-06-01

    In the present study, we aim to investigate the extent of soil contamination by Hg, particularly by anthropogenic Hg, and tentatively estimate the total Hg (Hg(T)) accumulation in topsoils (0-15 cm) in Fuyang, Zhejiang Province--a secondary Cu smelter of China. The results show that the levels of soil Hg in the vicinity of the smelters have been substantially elevated following local smelting activities. The spatial distribution of soil Hg in this area reveals a rapid decrease as the distance from the smelter reaches 1.5 km, which is probably due to the quick deposition process of particulate Hg and reactive gaseous Hg emitted from the smelters. The total accumulation of Hg(T) in the topsoils of the study area of 10.9 km(2) is approximately 365-561 kg and of which 346-543 kg might be contributed by anthropogenic emission alone with an annual emission of 17.3-27.2 kg Hg to the topsoils. PMID:19304360

  12. Phytoextraction for clean-up of low-level uranium contaminated soil evaluated.

    PubMed

    Vandenhove, H; Van Hees, M

    2004-01-01

    Spills in the nuclear fuel cycle have led to soil contamination with uranium. In case of small contamination just above release levels, low-cost yet sufficiently efficient remedial measures are recommended. This study was executed to test if low-level U contaminated sandy soil from a nuclear fuel processing site could be phytoextracted in order to attain the required release limits. Two soils were tested: a control soil (317 Bq 238U kg(-1)) and the same soil washed with bicarbonate (69 Bq 238U kg(-1)). Ryegrass (Lolium perenne cv. Melvina) and Indian mustard (Brassica juncea cv. Vitasso) were used as test plants. The annual removal of soil activity by the biomass was less than 0.1%. The addition of citric acid (25 mmol kg(-1)) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15,000 and 10,000 kg ha(-1), respectively, up to 3.5% and 4.6% of the soil activity could be removed annually by the biomass. With a desired activity reduction level of 1.5 and 5 for the bicarbonate-washed and control soil, respectively, it would take 10-50 years to attain the release limit. However, citric acid addition resulted in a decreased dry weight production. PMID:15162854

  13. Molecular-Level Processes Governing the Interaction of Contaminants with Iron and Manganese Oxides - Final Report

    SciTech Connect

    Brown Jr., G. E.; Chambers, S. A.

    1999-10-31

    Many of the inorganic and organic contaminants present in sediments at DOE sites can be altered or destroyed by reduction and oxidation (redox) reactions occurring at mineral surfaces. A fundamental understanding of such redox processes provided by molecular-level studies on structurally and compositionally well-defined mineral surfaces will lead to: (i) improved models of contaminant fate and transport in geochemical systems, and (ii) optimized manipulation of these processes for remediation purposes. To contribute to this understanding, we will study, both experimentally and theoretically, redox processes involving three important contaminants - chromate ion, carbon tetrachloride, and trichloroethene TCE, on the following iron and manganese oxides - hematite, magnetite, maghemite, and pyrolusite. These oxides and their hydroxylated analogs commonly occur as coatings on minerals or as interfaces in the subsurface environment. Single-crystal surfaces of these oxides will be synthesized in carefully controlled fashion by molecular beam epitaxy. These surfaces, as well as high surface are powdered samples of these oxides, will be used in spectroscopic and kinetic experiments in both aqueous and gas phases. Our goal is to identify products and to determine the kinetics and mechanisms of surface-catalyzed redox reaction of Cr(VI) and CR(III), and the reductive dechlorination of carbon tetrachloride and TCE. The combination of theory and experiment will provide the base information needed to scale from the molecular level to the microscopic grain level minerals.

  14. Determination of N-nitrosodimethylamine as part-per-trillion levels drinking waters and contaminated groundwaters

    SciTech Connect

    Tomkins, B.A.; Griest, W.H.; Higgins, C.E.

    1995-12-01

    The carcinogen N-nitrosodimethylamine (NDMA) may be quantitated routinely at ultratrace (ng/L) levels in drinking water or contaminated groundwater. NDMA is selectively detected using a chemiluminescent nitrogen detector (CLND) operated in its nitrosamine-selective mode. The reporting limit for this procedure, evaluated using two independent statistically unbiased protocols, is 2 ng of NDMA/L. A related procedure, employing an automatic sampler instead of the short-path thermal desorber, provides convenient analysis of heavily contaminated samples and exhibits a reporting limit (same protocols cited previously) of 110 ng of NDMA/L. When the two methods are used together in a `two-tiered` protocol, NDMA concentrations spanning 4 orders of magnitude (ng/L to {mu}g/L levels) may be measured routinely. The low-level procedure employing only the short-path thermal desorber was applied successfully to three sources of drinking water, where NDMA concentrations ranged between 2 and 10 ng of NDMA/L. The two-tiered protocol was applied to a series of contaminated groundwaters whose NDMA concentrations ranged between approximately 10-7000 ng of NDMA/L. The results agreed with those obtained from an independent collaborating laboratory, which used a different analytical procedure. 39 refs., 6 figs., 6 tabs.

  15. Influences of ammonia contamination on leaching from air-pollution-control residues.

    PubMed

    Guan, Zhenzhen; Chen, Dezhen; Astrup, Thomas Fruergaard

    2014-12-01

    Application of selective non-catalytic reduction systems at municipal solid waste incinerators (MSWIs) often involves over-stoichiometric injection of ammonia into flue gases. Un-reacted ammonia may be deposited on fly ash particles and can ultimately influence the leaching behaviour of air-pollution-control (APC) residues. Batch tests were conducted to investigate the impacts of ammonia levels on leaching of a range of metals (sodium, potassium, calcium, aluminium, chromium, iron, lead, cadmium, copper, nickel and zinc), as well as chloride and dissolved organic carbon (DOC). Specific conductivity was also identified to reflect the soluble components. The results showed that with ammonia concentrations rising from a background level of 4 to 26,400 mg l(-1), the specific conductivity increased by 2-7 times as pH varied from alkaline to acidic values. DOC release was also significantly enhanced with high ammonia levels of 1400 mg l(-1) or higher at pH > 9; however at these high ammonia concentrations, the role of DOC in cadmium, copper, nickel and zinc leaching was negligible. Based on the experimental data, chloride, sodium and potassium were leached at high concentrations regardless of pH and ammonia concentrations. For aluminium, chromium, iron and lead, ammonia had little impact on their leaching behaviour. With respect to cadmium, copper, nickel and zinc, high ammonia concentrations significantly increased leaching in the pH range of 8-12 due to the formation of metal-ammonia complexes, which was also proved in the speciation calculations. However, the overall results suggest that typical levels of ammonia injection in MSWIs are not likely to affect metal leaching from APC residues. PMID:25147306

  16. Influences of ammonia contamination on leaching from air-pollution-control residues.

    PubMed

    Guan, Zhenzhen; Chen, Dezhen; Astrup, Thomas Fruergaard

    2014-12-01

    Application of selective non-catalytic reduction systems at municipal solid waste incinerators (MSWIs) often involves over-stoichiometric injection of ammonia into flue gases. Un-reacted ammonia may be deposited on fly ash particles and can ultimately influence the leaching behaviour of air-pollution-control (APC) residues. Batch tests were conducted to investigate the impacts of ammonia levels on leaching of a range of metals (sodium, potassium, calcium, aluminium, chromium, iron, lead, cadmium, copper, nickel and zinc), as well as chloride and dissolved organic carbon (DOC). Specific conductivity was also identified to reflect the soluble components. The results showed that with ammonia concentrations rising from a background level of 4 to 26,400 mg l(-1), the specific conductivity increased by 2-7 times as pH varied from alkaline to acidic values. DOC release was also significantly enhanced with high ammonia levels of 1400 mg l(-1) or higher at pH > 9; however at these high ammonia concentrations, the role of DOC in cadmium, copper, nickel and zinc leaching was negligible. Based on the experimental data, chloride, sodium and potassium were leached at high concentrations regardless of pH and ammonia concentrations. For aluminium, chromium, iron and lead, ammonia had little impact on their leaching behaviour. With respect to cadmium, copper, nickel and zinc, high ammonia concentrations significantly increased leaching in the pH range of 8-12 due to the formation of metal-ammonia complexes, which was also proved in the speciation calculations. However, the overall results suggest that typical levels of ammonia injection in MSWIs are not likely to affect metal leaching from APC residues.

  17. New Remote Method for Estimation of Contamination Levels of Reactor Equipment - 13175

    SciTech Connect

    Danilovich, Alexey; Ivanov, Oleg; Potapov, Victor; Semenov, Sergey; Semin, Ilya; Smirnov, Sergey; Stepanov, Vyacheslav; Volkovich, Anatoly

    2013-07-01

    Projects for decommissioning of shutdown reactors and reactor facilities carried out in several countries, including Russia. In the National Research Centre 'Kurchatov Institute' decontamination and decommissioning of the research reactor MR (Material Testing Reactor) has been initiated. The research reactor MR has a long history and consists of nine loop facilities for experiments with different kinds of fuel. During the operation of main and auxiliary equipment of reactors it was subjected to strong radioactive contamination. The character of this contamination requires individual strategies for the decontamination work. This requires information about the character of the distribution of radioactive contamination of equipment in the premises. A detailed radiation survey of these premises using standard dosimetric equipment is almost impossible because of high levels of radiation and high-density of the equipment that does not allow identifying the most active fragments using standard tools of measurement. The problem can be solved using the method of remote measurements of distribution of radioactivity with help of the collimated gamma-ray detectors. For radiation surveys of the premises of loop installations remotely operated spectrometric collimated system was used [1, 2, 3]. As a result of the work, maps of the distribution of activity and dose rate for surveyed premises were plotted and superimposed on its photo. The new results of measurements in different areas of the reactor and at its loop installations, with emphasis on the radioactive survey of highly-contaminated samples, are presented. (authors)

  18. Decreasing Enterobacter sakazakii (Cronobacter spp.) food contamination level with bacteriophages: prospects and problems

    PubMed Central

    Zuber, Sophie; Boissin‐Delaporte, Catherine; Michot, Lise; Iversen, Carol; Diep, Benjamin; Brüssow, Harald; Breeuwer, Pieter

    2008-01-01

    Summary Enterobacter sakazakii (Cronobacter spp.) is an opportunistic pathogen, which can cause rare, but life‐threatening infections in neonates and infants through feeding of a contaminated milk formula. We isolated 67 phages from environmental samples and tested their lytic host range on a representative collection of 40 E. sakazakii strains. A cocktail of five phages prevented the outgrowth of 35 out of 40 test strains in artificially contaminated infant formula. Two E. sakazakii phages represented prolate head Myoviridae. Molecular tests identified them as close relatives of Escherichia coli phage T4. The remaining three phages represented isometric head Myoviridae with large genome size of 140 and 200 kb, respectively, which belonged to two different DNA hybridization groups. A high dose of 108 pfu ml−1 of phage could effectively sterilize a broth contaminated with both high and low pathogen counts (106 and 102 cfu ml−1). In contrast, broth inoculated with 104 phage and 102 bacteria per ml first showed normal bacterial growth until reaching a cell titre of 105 cfu ml−1. Only when crossing this threshold, phage replication started, but it could not reduce the contamination level below 100 cfu ml−1. Phages could be produced with titres of 1010 pfu ml−1 in broth culture, but they were not stable upon freeze‐drying. Addition of trehalose or milk formula stabilized the phage preparation, which then showed excellent storage stability even at elevated temperature. PMID:21261874

  19. Gas-Phase Ambient Air Contaminants Exhibit Significant Dioxin-like and Estrogen-like Activity in Vitro

    PubMed Central

    Klein, Gail P.; Hodge, Erin M.; Diamond, Miriam L.; Yip, Amelia; Dann, Tom; Stern, Gary; Denison, Michael S.; Harper, Patricia A.

    2006-01-01

    Several adverse health effects, such as respiratory and cardiovascular morbidity, have been linked to exposure to particulate matter in ambient air; however, the biologic activity of gas-phase ambient organic air contaminants has not been examined as thoroughly. Using aryl hydrocarbon receptor (AHR)–based and estrogen receptor (ER)–based cell bioassay systems, we assessed the dioxin-like and estrogenic activities of gas-phase organic ambient air contaminants compared with those of particulate-phase contaminants using samples collected between seasons over 2 years from an urban and a rural location in the Greater Toronto Area, Canada. The concentration of the sum (∑) of polycyclic aromatic hydrocarbons, which was highest in the gas phase, was 10–100 times more abundant than that of ∑polychlorinated biphenyls, ∑nitro-polycyclic aromatic hydrocarbons, and ∑organochlorine pesticides, and 103 to 104 times more abundant than ∑polychlorinated dibenzo-p-dioxins/dibenzofurans. Gas-phase samples induced significant AHR- and ER-dependent gene expression. The activity of the gas-phase samples was greater than that of the particulate-phase samples in the estrogen assay and, in one case, in the AHR assay. We found no strong associations between either summer or winter seasons or urban or rural locations in the relative efficacy of the extracts in either the ER or AHR assay despite differences in chemical composition, concentrations, and abundance. Our results suggest that mechanistic studies of the health effects of ambient air must consider gas and particulate phases because chemicals present in both phases can affect AHR and ER signaling pathways. PMID:16675423

  20. Development of Level 3 (gridded) products for the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Granger, Stephanie L.; Leroy, Stephen S.; Manning, Evan M.; Fetzer, Eric J.; Oliphant, Robert B.; Braverman, Amy; Lee, Sung-Yung; Lambrigtsen, Bjom H.

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) sounding system is a suite of infrared and microwave instruments flown as part of NASA's Earth Observing System (EOS) onboard the Aqua platform. The AIRS dataset provides a daily, global view of Earth processes at a finer vertical resolution than ever before. However, analysis of the AIRS data is a daunting task given the sheer volume and complexity of the data. The volume of data produced by the EOS project is unprecedented; the AIRS project alone will produce many terabytes of data over the lifetime of the mission. This paper describes development of AIRS Level 3 data products that will help to alleviate problems of access and usability.

  1. Ground level air convection produces frost damage patterns in turfgrass.

    PubMed

    Ackerson, Bruce J; Beier, Richard A; Martin, Dennis L

    2015-11-01

    Frost injury patterns are commonly observed on the warm-season turfgrass species bermudagrass (Cynodon species Rich.), zoysiagrass (Zoysia species Willd.), and buffalograss [Bouteloua dactyloides (Nutt.) J.T. Columbus] in cool-temperate and subtropical zones. Qualitative observations of these injury patterns are presented and discussed. A model for the formation of such patterns based on thermal instability and convection of air is presented. The characteristic length scale of the observed frost pattern injury requires a temperature profile that decreases with height from the soil to the turfgrass canopy surface followed by an increase in temperature with height above the turfgrass canopy. This is justified by extending the earth temperature theory to include a turf layer with atmosphere above it. Then the theory for a thermally unstable layer beneath a stable region by Ogura and Kondo is adapted to a turf layer to include different parameter values for pure air, as well as for turf, which is treated as a porous medium. The earlier porous medium model of Thompson and Daniels proposed to explain frost injury patterns is modified to give reasonable agreement with observed patterns. PMID:25796203

  2. Ground level air convection produces frost damage patterns in turfgrass.

    PubMed

    Ackerson, Bruce J; Beier, Richard A; Martin, Dennis L

    2015-11-01

    Frost injury patterns are commonly observed on the warm-season turfgrass species bermudagrass (Cynodon species Rich.), zoysiagrass (Zoysia species Willd.), and buffalograss [Bouteloua dactyloides (Nutt.) J.T. Columbus] in cool-temperate and subtropical zones. Qualitative observations of these injury patterns are presented and discussed. A model for the formation of such patterns based on thermal instability and convection of air is presented. The characteristic length scale of the observed frost pattern injury requires a temperature profile that decreases with height from the soil to the turfgrass canopy surface followed by an increase in temperature with height above the turfgrass canopy. This is justified by extending the earth temperature theory to include a turf layer with atmosphere above it. Then the theory for a thermally unstable layer beneath a stable region by Ogura and Kondo is adapted to a turf layer to include different parameter values for pure air, as well as for turf, which is treated as a porous medium. The earlier porous medium model of Thompson and Daniels proposed to explain frost injury patterns is modified to give reasonable agreement with observed patterns.

  3. Ground level air convection produces frost damage patterns in turfgrass

    NASA Astrophysics Data System (ADS)

    Ackerson, Bruce J.; Beier, Richard A.; Martin, Dennis L.

    2015-11-01

    Frost injury patterns are commonly observed on the warm-season turfgrass species bermudagrass ( Cynodon species Rich.), zoysiagrass ( Zoysia species Willd.), and buffalograss [ Bouteloua dactyloides (Nutt.) J.T. Columbus] in cool-temperate and subtropical zones. Qualitative observations of these injury patterns are presented and discussed. A model for the formation of such patterns based on thermal instability and convection of air is presented. The characteristic length scale of the observed frost pattern injury requires a temperature profile that decreases with height from the soil to the turfgrass canopy surface followed by an increase in temperature with height above the turfgrass canopy. This is justified by extending the earth temperature theory to include a turf layer with atmosphere above it. Then the theory for a thermally unstable layer beneath a stable region by Ogura and Kondo is adapted to a turf layer to include different parameter values for pure air, as well as for turf, which is treated as a porous medium. The earlier porous medium model of Thompson and Daniels proposed to explain frost injury patterns is modified to give reasonable agreement with observed patterns.

  4. [Influence of atmospheric transport on air pollutant levels at a mountain background site of East China].

    PubMed

    Su, Bin-Bin; Xu, Ju-Yang; Zhang, Ruo-Yu; Ji, Xian-Xin

    2014-08-01

    Transport characteristics of air pollutants transported to the background atmosphere of East China were investigated using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) 4.8 model driven by NCEP reanalysis data during June 2011 to May 2012. Based on the air pollutants monitoring data collected at the National atmospheric background monitoring station (Wuyishan station) in Fujian Province, characteristics of different clustered air masses as well as the origins of highly polluted air masses were further examined. The results showed that 65% of all the trajectories, in which air masses mainly passed over highly polluted area of East China, Jiangxi province and upper air in desert areas of Northwest China, carried polluted air to the station, while the rest of trajectories (35%) with air masses originated from ocean could effectively remove air pollutants at the Wuyishan station. However, the impact on the air pollutants for each air mass group varied with seasons. Elevated SO2 concentrations observed at the background station were mainly influenced by coal burning activities in Northern China during heating season. The high CO concentrations were likely associated with the pollutants emission in the process of coal production and consumption in Anhui province. The elevated NO(x), O3, PM10 and PM2.5 concentrations were mostly impacted by East China with high levels of air pollutants.

  5. Persistent organic contaminants and steroid hormones levels in Morelet's crocodiles from the Southern Gulf of Mexico.

    PubMed

    Gonzalez-Jauregui, Mauricio; Valdespino, Carolina; Salame-Méndez, Arturo; Aguirre-León, Gustavo; Rendón-Vonosten, Jaime

    2012-04-01

    Effects of endocrine disruptors on reproductive variables of top predators, such as alligators and crocodiles, have long been cited. Due to their long life span, these predators provide us with historic contaminant annals. In this study we tried to test whether lifestyle (free-ranging vs. farm animals) and reproductive age of Morelet's crocodiles in Campeche, Mexico, affect the bioaccumulation of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Subsequently, we tested to see whether their concentration was related to steroid hormones (testosterone and estradiol-17β) levels once normal cyclic hormone variation and reproductive age had been taken into account. From the group of contaminants considered (analyzed as families), only frequency of hexachlorocyclohexanes (∑HCH) and ∑PCB permitted analyses. Whereas there was a greater concentration of ∑HCH bioaccumulated by free-ranging crocodiles, ∑PCB was found in equal quantities in free-ranging and farm animals. No difference was observed in relation to reproductive age for any of the contaminants. However, ∑PCB concentrations were related to testosterone levels among female crocodiles. This androgenic effect of ∑PCB has not been reported previously. Because testosterone promotes aggressive behavior in vertebrates, excessive aggression during the estrous season, or when female crocodiles should be caring for their young, could result in reproductive failure in Morelet's crocodiles and potential long-term decline of the population.

  6. Direct simulation Monte Carlo prediction of on-orbit contaminant deposit levels for HALOE

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael S.; Rault, Didier F. G.

    1994-01-01

    A three-dimensional version of the direct simulation Monte Carlo method is adapted to assess the contamination environment surrounding a highly detailed model of the Upper Atmosphere Research Satellite. Emphasis is placed on simulating a realistic, worst-case set of flow field and surface conditions and geometric orientations for the satellite in order to estimate an upper limit for the cumulative level of volatile organic molecular deposits at the aperture of the Halogen Occultation Experiment. A detailed description of the adaptation of this solution method to the study of the satellite's environment is also presented. Results pertaining to the satellite's environment are presented regarding contaminant cloud structure, cloud composition, and statistics of simulated molecules impinging on the target surface, along with data related to code performance. Using procedures developed in standard contamination analyses, along with many worst-case assumptions, the cumulative upper-limit level of volatile organic deposits on HALOE's aperture over the instrument's 35-month nominal data collection period is estimated at about 13,350 A.

  7. High-Level Waste Tanks Multi-Dimensional Contaminant Transport Model Development

    SciTech Connect

    Collard, L.B.

    1999-11-15

    A suite of multi-dimensional computer models was developed to analyze the transport of residual contamination from high-level waste tanks through the subsurface to seeplines. Cases analyzed ranged from all the tanks in the F- and H-tank farms for an overall look; to the Tank 17-20 4-pack to study plume interaction; to individual tanks, such as Tank 17 and 20 for comparison with one-dimensional and modeling. The main purpose of this work was to develop and test the models, so only two relatively conservative contaminants were examined, Tc-99 and I-129. More complex analyses, such as solubility-limited species and radionuclides that head a decay chain were not addressed in this study.

  8. Procedures for addressing uncertainty and variability in exposure to characterize potential health risk from trichloroethylene contaminated ground water at Beale Air Force Base in California

    SciTech Connect

    Daniels, J I; Bogen, K T; Hall, L C

    1999-10-05

    Conservative deterministic, screening-level calculations of exposure and risk commonly are used in quantitative assessments of potential human-health consequences from contaminants in environmental media. However, these calculations generally are based on multiple upper-bound point estimates of input parameters, particularly for exposure attributes, and can therefore produce results for decision makers that actually overstate the need for costly remediation. Alternatively, a more informative and quantitative characterization of health risk can be obtained by quantifying uncertainty and variability in exposure. This process is illustrated in this report for a hypothetical population at a specific site at Beale Air Force Base in California, where there is trichloroethylene (TCE) contaminated ground water and a potential for future residential use. When uncertainty and variability in exposure were addressed jointly for this case, the 95th-percentile upper-bound value of individual excess lifetime cancer risk was a factor approaching 10 lower than the most conservative deterministic estimate. Additionally, the probability of more than zero additional cases of cancer can be estimated, and in this case it is less than 0.5 for a hypothetical future residential population of up to 26,900 individuals present for any 7.6-y interval of a 70-y time period. Clearly, the results from application of this probabilistic approach can provide reasonable and equitable risk-acceptability criteria for a contaminated site.

  9. No enhancement in bioconcentration of organic contaminants by low levels of DOM

    USGS Publications Warehouse

    Haitzer, M.; Akkanen, J.; Steinberg, C.; Kukkonen, J.V.K.

    2001-01-01

    The aim of the present work was to systematically study the effect of low concentrations of dissolved organic matter (DOM) on the bioconcentration of organic contaminants, in order to show whether the phenomenon of enhanced bioconcentration factors (BCFs), that has been reported in the literature, is generally found at low levels of DOM or if BCF enhancements are more likely due to a random scatter in the experimental data. The first part of the study tested the hypothesis that low levels of DOM affect the uptake kinetics of organic contaminants, leading to transient enhancements of BCFs, relative to DOM-free controls, which could have been reported as BCF enhancements in short-term studies. We found that the presence of low concentrations of two different types of DOM consistently decreased the bioconcentration of benzo[a]pyrene (BaP) in the water flea Daphnia magna at all exposure times (1-24 h), and that no transient BCF enhancements occurred. The second part of the study systematically investigated if low concentrations of DOM from a wide range of different aquatic systems can cause enhancements in the bioconcentration of organic contaminants. Water fleas were exposed to combinations of four different organic contaminants (BaP, tetrachlorobiphenyl, pentachlorophenol and naphthalene) with low concentrations of 12 different types of DOM that had been collected from various regions throughout Europe. In several of the DOM treatments, we found mean BCFs being higher than mean BCFs in the controls (especially for naphthalene). This shows that the experimental setup used in this study (and similarly in previous studies) can produce seeming BCF enhancements at low concentrations of DOM. However, statistical analyses showed that treatment means were not significantly different from control means. Thus, this systematic study suggests that the BCF enhancements that have been reported in the literature are more likely the result of random, experimental variations than the

  10. Auxiliary analyses in support of performance assessment of a hypothetical low-level waste facility: Two-phase flow and contaminant transport in unsaturated soils with application to low-level radioactive waste disposal. Volume 2

    SciTech Connect

    Binning, P.; Celia, M.A.; Johnson, J.C.

    1995-05-01

    A numerical model of multiphase air-water flow and contaminant transport in the unsaturated zone is presented. The multiphase flow equations are solved using the two-pressure, mixed form of the equations with a modified Picard linearization of the equations and a finite element spatial approximation. A volatile contaminant is assumed to be transported in either phase, or in both phases simultaneously. The contaminant partitions between phases with an equilibrium distribution given by Henry`s Law or via kinetic mass transfer. The transport equations are solved using a Galerkin finite element method with reduced integration to lump the resultant matrices. The numerical model is applied to published experimental studies to examine the behavior of the air phase and associated contaminant movement under water infiltration. The model is also used to evaluate a hypothetical design for a low-level radioactive waste disposal facility. The model has been developed in both one and two dimensions; documentation and computer codes are available for the one-dimensional flow and transport model.

  11. Source levels of northern elephant seal vocalizations in-air

    NASA Astrophysics Data System (ADS)

    Insley, Stephen J.; Southall, Brandon L.

    2005-09-01

    Accurate measurements of vocalization sound-pressure levels are necessary to determine the acoustical active space of animals in natural and human-altered ambient noise conditions. Despite this basic need, such data are limited or nonexistent for most species. Our study characterized aerial ambient noise and vocalization source levels for northern elephant seals during the breeding season. Subjects were adult males, lactating females, and dependent offspring (pups) at An~o Nuevo State Reserve. Source level measurements were made using a Type 1 sound level meter and calibrated microphones on-axis: (1) at 1 m; (2) at several known distances (laser measured); and (3) simultaneously at 1 m and a second known distance. Concurrent ambient noise conditions were measured in situ (non-weighted 5 min Leq integrated averages) and recorded for later spectral analysis. Measurements were made at two sites, one relatively noisy and the other relatively quiet, to determine whether animals compensate for higher noise conditions by increasing source levels (Lombard effect). Results indicate a wide range in signal strength, particularly for adult males whose vocalization source levels appear to be correlated with dominance rank and related to ambient noise conditions. The Lombard effect was not observed for adult females or elephant seal pups.

  12. Personal, indoor and outdoor air pollution levels among pregnant women

    NASA Astrophysics Data System (ADS)

    Schembari, Anna; Triguero-Mas, Margarita; de Nazelle, Audrey; Dadvand, Payam; Vrijheid, Martine; Cirach, Marta; Martinez, David; Figueras, Francesc; Querol, Xavier; Basagaña, Xavier; Eeftens, Marloes; Meliefste, Kees; Nieuwenhuijsen, Mark J.

    2013-01-01

    AimThe aims of this study were to investigate the relationship between pregnant women's personal exposures to NOx, NO2, PM2.5 concentration and absorbance as a marker for black carbon and their indoor and outdoor concentration levels at their residence, and also to identify predictors of personal exposure and indoor levels using questionnaire and time activity data. MethodWe recruited 54 pregnant women in Barcelona who carried a personal PM2.5 sampler for two days and NOx/NO2 passive badges for one week, while indoor and outdoor PM2.5 and NOx/NO2 levels at their residence were simultaneously measured. Time activity and house characteristics were recorded. Gravimetry determinations for PM2.5 concentration and absorbance measurements were carried out on the PM2.5 filter samples. ResultsLevels of personal exposure to NOx, PM2.5 and absorbance were slightly higher than indoor and outdoor levels (geometric mean of personal NOx = 61.9 vs indoor NOx = 60.6 μg m-3), while for NO2 the indoor levels were slightly higher than the personal ones. Generally, there was a high statistically significant correlation between personal exposure and indoor levels (Spearman's r between 0.78 and 0.84). Women spent more than 60% of their time indoors at home. Ventilation of the house by opening the windows, the time spent cooking and indicators for traffic intensity were re-occurring statistically significant determinants of the personal and indoor pollutants levels with models for NOx explaining the 55% and 60% of the variability respectively, and models for NO2 explaining the 39% and 16% of the variability respectively. Models for PM2.5 and absorbance explained the least of the variability. ConclusionOur findings improve the current understanding of the characterization and inter-associations between personal, indoor and outdoor pollution levels among pregnant women. Variability in personal and indoor NOx and to a lesser extent NO2 levels could be explained well, but not the variability

  13. Factors Affecting Parent's Perception on Air Quality-From the Individual to the Community Level.

    PubMed

    Guo, Yulin; Liu, Fengfeng; Lu, Yuanan; Mao, Zongfu; Lu, Hanson; Wu, Yanyan; Chu, Yuanyuan; Yu, Lichen; Liu, Yisi; Ren, Meng; Li, Na; Chen, Xi; Xiang, Hao

    2016-01-01

    The perception of air quality significantly affects the acceptance of the public of the government's environmental policies. The aim of this research is to explore the relationship between the perception of the air quality of parents and scientific monitoring data and to analyze the factors that affect parents' perceptions. Scientific data of air quality were obtained from Wuhan's environmental condition reports. One thousand parents were investigated for their knowledge and perception of air quality. Scientific data show that the air quality of Wuhan follows an improving trend in general, while most participants believed that the air quality of Wuhan has deteriorated, which indicates a significant difference between public perception and reality. On the individual level, respondents with an age of 40 or above (40 or above: OR = 3.252; 95% CI: 1.170-9.040), a higher educational level (college and above: OR = 7.598; 95% CI: 2.244-25.732) or children with poor healthy conditions (poor: OR = 6.864; 95% CI: 2.212-21.302) have much more negative perception of air quality. On the community level, industrial facilities, vehicles and city construction have major effects on parents' perception of air quality. Our investigation provides baseline information for environmental policy researchers and makers regarding the public's perception and expectation of air quality and the benefits to the environmental policy completing and enforcing.

  14. Factors Affecting Parent's Perception on Air Quality-From the Individual to the Community Level.

    PubMed

    Guo, Yulin; Liu, Fengfeng; Lu, Yuanan; Mao, Zongfu; Lu, Hanson; Wu, Yanyan; Chu, Yuanyuan; Yu, Lichen; Liu, Yisi; Ren, Meng; Li, Na; Chen, Xi; Xiang, Hao

    2016-01-01

    The perception of air quality significantly affects the acceptance of the public of the government's environmental policies. The aim of this research is to explore the relationship between the perception of the air quality of parents and scientific monitoring data and to analyze the factors that affect parents' perceptions. Scientific data of air quality were obtained from Wuhan's environmental condition reports. One thousand parents were investigated for their knowledge and perception of air quality. Scientific data show that the air quality of Wuhan follows an improving trend in general, while most participants believed that the air quality of Wuhan has deteriorated, which indicates a significant difference between public perception and reality. On the individual level, respondents with an age of 40 or above (40 or above: OR = 3.252; 95% CI: 1.170-9.040), a higher educational level (college and above: OR = 7.598; 95% CI: 2.244-25.732) or children with poor healthy conditions (poor: OR = 6.864; 95% CI: 2.212-21.302) have much more negative perception of air quality. On the community level, industrial facilities, vehicles and city construction have major effects on parents' perception of air quality. Our investigation provides baseline information for environmental policy researchers and makers regarding the public's perception and expectation of air quality and the benefits to the environmental policy completing and enforcing. PMID:27187432

  15. Dose coefficients and derived guidance and clinical decision levels for contaminated wounds

    SciTech Connect

    Bertelli, Luiz; Toohey, Richard E

    2009-01-01

    The NCRP Wound Model describing the retention of selected radionuclides at the site of a contaminated wound and their uptake into the transfer compartment has been combined with the ICRP element-specific systemic models for those radionuclides to derive dose coefficients for intakes via contaminated wounds. Those coefficients have been used to generate derived guidance levels (i.e., the activity in a wound that would result in an effective dose of 20 or 50 mSv, or in some cases, a committed organ equivalent dose of 500 mSv), and clinical decision levels (i.e., activity levels that would indicate the need for consideration of medical intervention to remove activity from the wound site or administration of decorporation therapy or both), typically set at 5 times the derived guidance levels. Data are provided for the radionuclides commonly encountered at nuclear power plants and nuclear weapons, fuel fabrication or recycling, waste disposal, medical and research facilities. These include: {sup 60}Co, {sup 90}Sr, {sup 99m}Tc, {sup 131}I, {sup 137}Cs, {sup 192}Ir, {sup 210}Po, {sup 226,228}Ra, {sup 228,232}Th, {sup 235,238}U, {sup 237}Np, {sup 238,239}Pu, {sup 241}Am, {sup 242,244}Cm, and {sup 252}Cf.

  16. Magnitude and distribution of canine fecal contamination and helminth eggs in two areas of different urban structure, Greater Buenos Aires, Argentina.

    PubMed

    Rubel, D; Wisnivesky, C

    2005-11-01

    The canine fecal contamination and the potential transmission of parasites to human and canine populations represent a public health problem of cosmopolitan importance. The objectives of this work were to evaluate the magnitude of fecal and parasite contamination in two suburban areas of different characteristics, and to investigate their distribution in various urban microenvironments such as yards, green spaces and sidewalks. The areas were referred to as middle-income neighbourhood (MIN) and low-income neighbourhood (LIN). To evaluate fecal contamination and its distribution, feces were counted and areas surveyed were calculated. The parasite contamination was evaluated from the prevalence of helminthosis found in a randomly selected fecal sample of the canine population in each of the study areas. The respective median fecal densities in MIN and LIN were 0.11 and 0.12 feces/m2 for green spaces, 0.10 and 0.19 feces/m2 for sidewalks (Mann-Whitney test, p<0.05), and 0.04 and 0.07 feces/m2 for households. In all the surveyed environments, dogs were free-ranging animals and preferred to defecate on grass surfaces rather than on bare soil, tile or sand. In MIN and LIN the respective prevalences were 40% and 70% for helminths in general (Chi square=15.17, p<0.01), 14 and 53% for Ancylostoma (Chi square=23.99, p<0.01), 9 and 17% for Toxocara (p>0.05), and 26 and 38% for Trichuris (p>0.05). Sidewalks were the most contaminated environments in LIN. The level of infected feces in sidewalks and yards was higher in LIN than in MIN (Mann-Whitney test, p<0.05). This study includes a discussion of the influence of variables such as canine population density, sidewalk structure and amount of available green spaces on the distribution of fecal contamination, and results obtained are compared with those previously recorded for Buenos Aires City. An increasing gradient of contamination by canine feces and parasites was observed as socioeconomic status decreased, the canine

  17. 210Pb dating of sediments in a heavily contaminated drainage channel to the La Plata estuary in Buenos Aires, Argentina.

    PubMed

    Di Gregorio, D E; Fernández Niello, J O; Huck, H; Somacal, H; Curutchet, G

    2007-01-01

    Concentrations of (210)Pb and (137)Cs in sediment samples collected from two cores at a drainage channel to the La Plata river estuary in Buenos Aires, Argentina, were measured using ultralow-background detection systems. The (210)Pb data were used to determine the rate of sediment accumulation of the sites. These results were correlated with some heavy metal (chromium and lead) concentrations of the samples in an attempt to characterize the historical input of contaminants due to the industrial development, which has taken place in this area over the last century. The (137)Cs measurements demonstrate that cesium dating is not adequate in regions of the southern hemisphere.

  18. Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake.

    PubMed

    Thienpont, Joshua R; Korosi, Jennifer B; Hargan, Kathryn E; Williams, Trisha; Eickmeyer, David C; Kimpe, Linda E; Palmer, Michael J; Smol, John P; Blais, Jules M

    2016-08-17

    Giant Mine, located in the city of Yellowknife (Northwest Territories, Canada), is a dramatic example of subarctic legacy contamination from mining activities, with remediation costs projected to exceed $1 billion. Operational between 1948 and 2004, gold extraction at Giant Mine released large quantities of arsenic and metals from the roasting of arsenopyrite ore. We examined the long-term ecological effects of roaster emissions on Pocket Lake, a small lake at the edge of the Giant Mine lease boundary, using a spectrum of palaeoenvironmental approaches. A dated sedimentary profile tracked striking increases (approx. 1700%) in arsenic concentrations coeval with the initiation of Giant Mine operations. Large increases in mercury, antimony and lead also occurred. Synchronous changes in biological indicator assemblages from multiple aquatic trophic levels, in both benthic and pelagic habitats, indicate dramatic ecological responses to extreme metal(loid) contamination. At the peak of contamination, all Cladocera, a keystone group of primary consumers, as well as all planktonic diatoms, were functionally lost from the sediment record. No biological recovery has been inferred, despite the fact that the bulk of metal(loid) emissions occurred more than 50 years ago, and the cessation of all ore-roasting activities in Yellowknife in 1999. PMID:27534958

  19. Changes in contaminant distributions with trophic level in a marine food chain study

    SciTech Connect

    Pruell, R.J.; Johnson, M.W.; Taplin, B.K.; McGovern, D.G.; Montmarquet, B.T.

    1994-12-31

    A laboratory study was designed to investigate the transfer of chlorinated organic contaminants from sediments to marine biota in a simplified marine food chain. Sediments collected from the Passaic River, NJ, which contained high concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), PCBs and chlorinated pesticides, were used as the contamination source. Polychaete worms (Nereis virens) were exposed to Passaic River sediment for 70 days to allow steady-state concentrations to be achieved and then these organisms were fed to a crustacean, the American lobster (Homarus americanus). Contaminant distributions were altered significantly as they passed from sediments to polychaetes and then to the lobster. PCDDs and PCDFs containing four or five chlorines were accumulated by the polychaetes and lobster; however, the highly chlorinated congeners were not accumulated. PCB patterns in lobsters indicated that these organisms metabolized many PCB congeners. Coplanar PCBs did not appear to be metabolized and therefore became enriched relative to total PCB levels in the lobsters. Lobsters also greatly altered the ratios of chlordane and DDT series compounds relative to those in the sediments and polychaetes.

  20. Allowable Residual Contamination Levels in soil for decommissioning the Shippingport Atomic Power Station site

    SciTech Connect

    Kennedy, W.E. Jr.; Napier, B.A.; Soldat, J.K.

    1983-09-01

    As part of decommissioning the Shippingport Atomic Power Station, a fundamental concern is the determination of Allowable Residual Contamination Levels (ARCL) for radionuclides in the soil at the site. The ARCL method described in this report is based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for unrestricted use of the land after decommissioning. In addition to naturally occurring radionuclides and fallout from weapons testing, soil contamination could potentially come from five other sources. These include operation of the Shippingport Station as a pressurized water reactor, operations of the Shippingport Station as a light-water breeder, operation of the nearby Beaver Valley reactors, releases during decommissioning, and operation of other nearby industries, including the Bruce-Mansfield coal-fired power plants. ARCL values are presented for 29 individual radionculides and a worksheet is provided so that ARCL values can be determined for any mixture of the individual radionuclides for any annual dose limit selected. In addition, a worksheet is provided for calculating present time soil concentration value that will decay to the ARCL values after any selected period of time, such as would occur during a period of restricted access. The ARCL results are presented for both unconfined (surface) and confined (subsurface) soil contamination. The ARCL method and results described in this report provide a flexible means of determining unrestricted-use site release conditions after decommissioning the Shippingport Atomic Power Station.

  1. Water level management and contaminant exposure to tree swallows nesting on the Upper Mississippi River

    USGS Publications Warehouse

    Custer, T.W.; Dummer, P.M.; Custer, Christine M.; Li, A.U.; Warburton, D.; Melancon, M.J.; Hoffman, D.J.; Matson, C.W.; Bickham, J.W.

    2007-01-01

    The U.S. Army Corps of Engineers conducted a water drawdown on Navigation Pool 8 of the Upper Mississippi River during the summers of 2001 and 2002 to increase aquatic vegetation production and thereby improve fish and wildlife habitat. Flooding of previously dried wetlands, however, may increase the rate of mercury methylation and make mercury more available to terrestrial vertebrates that feed in aquatic environments. Our objective was to determine if mercury, other elements, and organochlorine contaminants were more available to vertebrates following the 2001 drawdown. Tree swallow (Tachycineta bicolor) eggs and nestlings were collected at two sites on Pool 8 and a nearby Reference site in 2000 (pre-2001 drawdown), 2001 (pre-2001 drawdown) and 2002 (post-2001 drawdown) and tissues were analyzed for mercury, other elements, and organochlorine contaminants. Bioindicator measurements of genetic damage, oxidative stress, ethoxyresorufin-O-dealkylase activity, and the ratio of liver to nestling mass were also measured in nestlings at all sites and all years. Based on a multivariate analysis, the 2001 drawdown of Pool 8 did not influence element concentrations, organochlorine concentrations, or bioindicator response. Concentrations of inorganic and organochlorine contaminants in tree swallow eggs and nestlings were not at toxic levels. Hatching success did not differ among years and was comparable to the nationwide average.

  2. Water level management and contaminant exposure to tree swallows nesting on the Upper Mississippi River.

    PubMed

    Custer, Thomas W; Dummer, Paul M; Custer, Christine M; Li, Azusa U; Warburton, David; Melancon, Mark J; Hoffman, David J; Matson, Cole W; Bickham, John W

    2007-10-01

    The U.S. Army Corps of Engineers conducted a water drawdown on Navigation Pool 8 of the Upper Mississippi River during the summers of 2001 and 2002 to increase aquatic vegetation production and thereby improve fish and wildlife habitat. Flooding of previously dried wetlands, however, may increase the rate of mercury methylation and make mercury more available to terrestrial vertebrates that feed in aquatic environments. Our objective was to determine if mercury, other elements, and organochlorine contaminants were more available to vertebrates following the 2001 drawdown. Tree swallow (Tachycineta bicolor) eggs and nestlings were collected at two sites on Pool 8 and a nearby Reference site in 2000 (pre-2001 drawdown), 2001 (pre-2001 drawdown) and 2002 (post-2001 drawdown) and tissues were analyzed for mercury, other elements, and organochlorine contaminants. Bioindicator measurements of genetic damage, oxidative stress, ethoxyresorufin-O-dealkylase activity, and the ratio of liver to nestling mass were also measured in nestlings at all sites and all years. Based on a multivariate analysis, the 2001 drawdown of Pool 8 did not influence element concentrations, organochlorine concentrations, or bioindicator response. Concentrations of inorganic and organochlorine contaminants in tree swallow eggs and nestlings were not at toxic levels. Hatching success did not differ among years and was comparable to the nationwide average. PMID:17286172

  3. A method for determining allowable residual contamination levels of radionuclide mixtures in soil

    SciTech Connect

    Napier, B.A.

    1982-05-01

    An important consideration in the disposal of radioactive wastes, and consequently in the preparation of plans for remedial actions at contaminated sites, is the amount of radioactive contamination that may be allowed to remain at any particular waste site. The allowable residual contamination level (ARCL) is dependent on the radiation dose limit imposed, the physical and environmental characteristics of the waste site, and the time at which exposure to the wastes is assumed to occur. The steps in generating an ARCL are generally as follows: (1) develop plausible, credible site-specific exposure scenario; (2) calculate maximum annual radiation doses to an individual for each radionuclide based on the existing physical characteristics of the waste site and the site-specific exposure scenario; (3) calculate the ARCL for the dose limit desired, including all radionuclides present, uncorrected for site cleanup or barrier considerations; and (4) apply any corrections for proposed cleanup activity or addition of barriers to waste migration or uptake to obtain the ARCL applicable to the proposed action. Use of this method allows appropriate application of resources to achieve uniform compliance with a single regulatory standard, i.e., a radiation dose rate limit. Application and modification of the ARCL method requires appropriate models of the environmental transport and fate of radionuclides. Example calculations are given for several specific waste forms and waste site types in order to demonstrate the technique and generate comparisons with other approaches.

  4. DDT in zebra mussels from Lake Maggiore (N. Italy): level of contamination and endocrine disruptions.

    PubMed

    Binelli, Andrea; Bacchetta, Renato; Mantecca, Paride; Ricciardi, Francesco; Provini, Alfredo; Vailati, Giovanni

    2004-08-10

    The DDT contamination of Lake Maggiore (Northern Italy) has been monitored since a serious pollution event occurred in 1996. To assess the environmental risk associated with this contamination, bioaccumulation data coupled with histopathological markers were evaluated on zebra mussel populations from two different contaminated sites from April 2001 to April 2002. Biomonitoring results showed high DDT pollution in 2001 because of a flood which transported DDTs still contained in the sediments of a polluted river to the lake. DDT concentrations reached values of 4-5 microg/g lipids, higher than those recorded in other industrialized countries but comparable to levels measured in developing ones. In the ovaries of the most highly polluted mussels, histological analyses showed a delay in oocyte maturation and a high incidence of pathological pictures mainly referable to oocyte degeneration and haemocytic infiltration. Moreover, despite the presence of mature sperms, in 2001 first male gamete release occurred about 2 months later than in females. These results indicated a neuroendocrine interference of DDT on Dreissena polymorpha reproduction and also showed that these invertebrates can be successfully used to evaluate ecological implications due to exposure to endocrine disruptors in freshwater environments.

  5. Incidence and levels of deoxynivalenol, fumonisins and zearalenone contaminants in animal feeds used in Korea in 2012.

    PubMed

    Kim, Dong-Ho; Lee, In-Hye; Do, Woo-Hyun; Nam, Woo-Seon; Li, Hua; Jang, Han-Sub; Lee, Chan

    2014-01-01

    The objective of this study was to evaluate the occurrence and levels of deoxynivalenol (DON), fumonisins B1 and B2 (FBs), and zearalenone (ZEN) contaminants in animal feeds used in Korea in 2012. Contamination with DON was observed in 91.33% and 53.33% in compound feeds and feed ingredients, respectively. Among compound feeds, poultry layer feed (laying) exhibited the highest contaminant level of 1.492 mg/kg. FBs contaminants were present in compound feeds and feed ingredients at 93.33% and 83.33%, respectively. Most poultry broiler (early) feeds were highly contaminated with FBs, and one of these feeds detected the level as 12.823 mg/kg as the highest level. The levels of ZEN in compound feeds and feed ingredients were 71.33% and 47%, respectively. Ninety-eight percent of compound feeds for cattle were contaminated with ZEN, and the highest contamination level of 0.405 mg/kg was observed in cattle fatting feeds. PMID:24366207

  6. Incidence and levels of deoxynivalenol, fumonisins and zearalenone contaminants in animal feeds used in Korea in 2012.

    PubMed

    Kim, Dong-Ho; Lee, In-Hye; Do, Woo-Hyun; Nam, Woo-Seon; Li, Hua; Jang, Han-Sub; Lee, Chan

    2013-12-23

    The objective of this study was to evaluate the occurrence and levels of deoxynivalenol (DON), fumonisins B1 and B2 (FBs), and zearalenone (ZEN) contaminants in animal feeds used in Korea in 2012. Contamination with DON was observed in 91.33% and 53.33% in compound feeds and feed ingredients, respectively. Among compound feeds, poultry layer feed (laying) exhibited the highest contaminant level of 1.492 mg/kg. FBs contaminants were present in compound feeds and feed ingredients at 93.33% and 83.33%, respectively. Most poultry broiler (early) feeds were highly contaminated with FBs, and one of these feeds detected the level as 12.823 mg/kg as the highest level. The levels of ZEN in compound feeds and feed ingredients were 71.33% and 47%, respectively. Ninety-eight percent of compound feeds for cattle were contaminated with ZEN, and the highest contamination level of 0.405 mg/kg was observed in cattle fatting feeds.

  7. Incidence and Levels of Deoxynivalenol, Fumonisins and Zearalenone Contaminants in Animal Feeds Used in Korea in 2012

    PubMed Central

    Kim, Dong-Ho; Lee, In-Hye; Do, Woo-Hyun; Nam, Woo-Seon; Li, Hua; Jang, Han-Sub; Lee, Chan

    2013-01-01

    The objective of this study was to evaluate the occurrence and levels of deoxynivalenol (DON), fumonisins B1 and B2 (FBs), and zearalenone (ZEN) contaminants in animal feeds used in Korea in 2012. Contamination with DON was observed in 91.33% and 53.33% in compound feeds and feed ingredients, respectively. Among compound feeds, poultry layer feed (laying) exhibited the highest contaminant level of 1.492 mg/kg. FBs contaminants were present in compound feeds and feed ingredients at 93.33% and 83.33%, respectively. Most poultry broiler (early) feeds were highly contaminated with FBs, and one of these feeds detected the level as 12.823 mg/kg as the highest level. The levels of ZEN in compound feeds and feed ingredients were 71.33% and 47%, respectively. Ninety-eight percent of compound feeds for cattle were contaminated with ZEN, and the highest contamination level of 0.405 mg/kg was observed in cattle fatting feeds. PMID:24366207

  8. Assessment of internal contamination problems associated with bioregenerative air/water purification systems

    NASA Technical Reports Server (NTRS)

    Johnson, Anne H.; Bounds, B. Keith; Gardner, Warren

    1990-01-01

    The emphasis is to characterize the mechanisms of bioregenerative revitalization of air and water as well as to assess the possible risks associated with such a system in a closed environment. Marsh and aquatic plants are utilized for purposes of wastewater treatment as well as possible desalinization and demineralization. Foliage plants are also being screened for their ability to remove toxic organics from ambient air. Preliminary test results indicate that treated wastewater is typically of potable quality with numbers of pathogens such as Salmonella and Shigella significantly reduced by the artificial marsh system. Microbiological analyses of ambient air indicate the presence of bacilli as well as thermophilic actinomycetes.

  9. Perfluorinated acids in air, rain, snow, surface runoff, and lakes: relative importance of pathways to contamination of urban lakes.

    PubMed

    Kim, Seung-Kyu; Kannan, Kurunthachalam

    2007-12-15

    Concentrations of perfluorinated acids (PFAs) were measured in various environmental matrices (air, rain, snow, surface runoff water, and lake water) in an urban area, to enable identification of sources and pathways of PFAs to urban water bodies. Total PFA concentrations ranged from 8.28 to 16.0 pg/ m3 (mean 11.3) in bulk air (sum of vapor and particulate phases), 0.91 to 13.2 ng/L (6.19) in rainwater, 0.91 to 23.9 ng/L (7.98) in snow, 1.11-81.8 ng/L (15.1 ng/L) in surface runoff water (SRW), and 9.49 to 35.9 ng/L (21.8) in lake water. Perfluorooctanoic acid (PFOA) was the predominant compound, accounting for > 35% of the total PFA concentrations, in all environmental matrices analyzed. Concentrations and relative compositions of PFAs in SRW were similar to those found for urban lakes. SRW contributes to contamination by PFOA in urban lakes. The measured concentration ratios of FTOH to PFOA in air were 1-2 orders of magnitude lower than the ratios calculated based on an assumption of exclusive atmospheric oxidation of FTOHs. Nevertheless, the mass balance analysis suggested the presence of an unknown input pathway that could contribute to a significant amount of total PFOA loadings to the lake. Flux estimates of PFOA at the air-water interface in the urban lake suggest net volatilization from water.

  10. Contaminant levels in fish and shellfish from the EMAP-Estuaries Louisiana Province

    SciTech Connect

    Benson, W.H.; O`Neal, J.M.; Allgood, J.C.; Summers, J.K.

    1994-12-31

    The Environmental Monitoring and Assessment Program-Estuaries (EMAP-E) is a research program designed to assess the ecological condition of the nation`s near-coastal ecosystems. The program is specifically designed to assess changes in ecological condition over broad biogeographic regions and over long time periods. The authors examined approximately 150 sites in the Gulf of Mexico between Anclote Anchorage, FL and the Rio Grande, TX during the summer of 1993. Species collected for chemical analyses included Atlantic croaker, catfish and shrimp. Results will be presented for contaminant levels in edible flesh analyzed for organochlorine and organophosphate pesticides, PCB congeners, butlytins, and a suite of trace elements.

  11. 77 FR 66595 - U.S. Air Force Broadcast of Consent Order, and Determination of Interest Level for a United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... Department of the Air Force U.S. Air Force Broadcast of Consent Order, and Determination of Interest Level for a United Launch Alliance (ULA) Consent Order Industry Day AGENCY: Headquarters Air Force, Deputy Under Secretary of the Air Force (Space). ACTION: Publicize Consent Order, and Determine Level...

  12. Field monitoring and performance evaluation of an in situ air sparging system at a gasoline-contaminated site.

    PubMed

    Hall, B L; Lachmar, T E; Dupont, R R

    2000-06-30

    In situ air sparging (IAS) has been used since the mid-1980s, but few carefully designed field studies have been performed to evaluate its effectiveness. In this study, 27 discrete monitoring points (MPs) were installed at a gasoline-contaminated site to investigate the efficacy of IAS. Each MP was instrumented with a pressure transducer and a Technalithics dissolved oxygen (DO) probe, and located so they could be used to characterize subsurface changes in total head and DO with depth, distance and orientation around a central injection well. Because the blower over-heated and automatically shut down after approximately 30 min and short-circuiting of air into two MPs occurred within 2 min, the study was designed as three sets of three 30-min trials. Longer trials would not have yielded different nor more insightful results. A volume of soil was not oxygenated during any injection. Instead, air traveled directly to at least four of seven different MPs during eight of the nine trials, probably as a result of an air bubble forming beneath a confining layer. The order of air arrival at the MPs varied during the first few trials, but once a preferential pathway was established, it did not collapse between trials and provided the shortest distance to the vadose zone during subsequent trials. Oxygen uptake rates estimated for MPs that received air during any trial exceeded the consumption rates of the Technalithics DO probes, and indicate that the probes could be used for estimating oxygen transfer during system operation or for oxygen uptake measurements during shut-down tests. The data from the monitoring system indicate that IAS is infeasible for remediation of soil and groundwater at this site due to its low horizontal hydraulic conductivity. Similar behavior is anticipated when IAS is applied at other sites with low hydraulic conductivity materials. PMID:10794912

  13. Field monitoring and performance evaluation of an in situ air sparging system at a gasoline-contaminated site.

    PubMed

    Hall, B L; Lachmar, T E; Dupont, R R

    2000-06-30

    In situ air sparging (IAS) has been used since the mid-1980s, but few carefully designed field studies have been performed to evaluate its effectiveness. In this study, 27 discrete monitoring points (MPs) were installed at a gasoline-contaminated site to investigate the efficacy of IAS. Each MP was instrumented with a pressure transducer and a Technalithics dissolved oxygen (DO) probe, and located so they could be used to characterize subsurface changes in total head and DO with depth, distance and orientation around a central injection well. Because the blower over-heated and automatically shut down after approximately 30 min and short-circuiting of air into two MPs occurred within 2 min, the study was designed as three sets of three 30-min trials. Longer trials would not have yielded different nor more insightful results. A volume of soil was not oxygenated during any injection. Instead, air traveled directly to at least four of seven different MPs during eight of the nine trials, probably as a result of an air bubble forming beneath a confining layer. The order of air arrival at the MPs varied during the first few trials, but once a preferential pathway was established, it did not collapse between trials and provided the shortest distance to the vadose zone during subsequent trials. Oxygen uptake rates estimated for MPs that received air during any trial exceeded the consumption rates of the Technalithics DO probes, and indicate that the probes could be used for estimating oxygen transfer during system operation or for oxygen uptake measurements during shut-down tests. The data from the monitoring system indicate that IAS is infeasible for remediation of soil and groundwater at this site due to its low horizontal hydraulic conductivity. Similar behavior is anticipated when IAS is applied at other sites with low hydraulic conductivity materials.

  14. Tracer studies for evaluation of in situ air sparging and in-well aeration system performance at a gasoline-contaminated site.

    PubMed

    Berkey, Jennifer S; Lachmar, Thomas E; Doucette, William J; Ryan Dupont, R

    2003-03-17

    Field-scale tracer studies were conducted at a gasoline-contaminated site in order to evaluate the effectiveness of in situ air sparging (IAS) and in-well aeration (IWA) in controlling the movement of soil gas and groundwater in the subsurface. The field site was comprised of silty sand (SM) and silty clay (CL), underlain by a clay layer at approximately 7.6 m. Depth to groundwater ranged from 2.4 to 3 m. Soil permeability and the natural hydraulic gradient were both low. Helium was used to trace the movement of soil gas in the unsaturated zone during the IAS field study, and successfully confirmed short-circuit pathways for injected air and demonstrated the limited distribution of injected gases at this site. Fluorescein, bromide, and rhodamine were used to trace the movement of groundwater during the IWA system field study, and successfully documented the inability of the IWA system to recirculate enough groundwater to enhance subsurface dissolved oxygen levels or to remediate groundwater by air stripping at this site. The inability of the systems to remediate the site was likely due to site conditions which consist of low-permeability soils and decreasing permeability with depth. As a result, relatively impermeable layers exist at the depth of the IAS screen and the lower IWA screen. These site conditions are not conducive to successful performance of either remediation system.

  15. Assessment of PCDD/Fs levels in soil at a contaminated sawmill site in Sweden--a GIS and PCA approach to interpret the contamination pattern and distribution.

    PubMed

    Henriksson, S; Hagberg, J; Bäckström, M; Persson, I; Lindström, G

    2013-09-01

    Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) were analysed in soil from a Swedish sawmill site where chlorophenols (CPs) had been used more than 40 years ago. The most contaminated area at the site was the preservation subarea where the PCDD/F WHO2005-TEQ level was 3450 times higher than the current Swedish guideline value of 200 ng TEQ/kg soil for land for industrial use. It was also shown that a fire which destroyed the sawmill might have affected the congener distribution at the concerned areas. To get a broader picture of the contamination both GIS (spatial interpolation analysis) and multivariate data analysis (PCA) were applied to visualize and compare PCDD/F levels as well as congener distributions at different areas at the site. It is shown that GIS and PCA are powerful tools in decisions on future investigations, risk assessments and remediation of contaminated sites.

  16. Field study of pulsed air sparging for remediation of petroleum hydrocarbon contaminated soil and groundwater.

    PubMed

    Yang, Xiaomin; Beckmann, Dennis; Fiorenza, Stephanie; Niedermeier, Craig

    2005-09-15

    Recent laboratory-scale studies strongly suggested an advantage to operating air-sparging systems in a pulsed mode; however, little definitive field data existed to support the laboratory-scale observations. This study aimed to evaluate the performance of a field-scale pulsed air-sparging system during a short-term pilot test and during long-term system operation. The air-sparging system consisted of 32 sparging points and had been previously operated in a continuous mode for two years before the field study was performed. The field study used instruments with continuous data logging capabilities to monitor the dynamic responses of groundwater and soil vapor parameters to air injection. The optimum pulsing frequency was based on the evidence that the hydrocarbon volatilization and oxygen dissolution rates dramatically dropped after the air-sparging system reached steady state. The short-term pilot test results indicated a substantial increase in hydrocarbon volatilization and biodegradation in pulsed operation. On the basis of the results of the pilottest, the air-sparging system was set to operate in a pulsed mode at an optimum pulsing frequency. Operation parameters were collected 2, 8, and 12 months after the start of the pulsed operation. The long-term monitoring results showed thatthe pulsed operation increased the average hydrocarbon removal rate (kg/day) by a factor of up to 3 as compared to the previous continuous operation. The pulsed air sparging has resulted in higher reduction rates of dissolved benzene, toluene, ethylbenzene, and xylenes (BTEX) than were observed during the continuous operation. Among BTEX, benzene's reduction rate was the highest during the pulsed air-sparging operation. PMID:16201659

  17. Field study of pulsed air sparging for remediation of petroleum hydrocarbon contaminated soil and groundwater.

    PubMed

    Yang, Xiaomin; Beckmann, Dennis; Fiorenza, Stephanie; Niedermeier, Craig

    2005-09-15

    Recent laboratory-scale studies strongly suggested an advantage to operating air-sparging systems in a pulsed mode; however, little definitive field data existed to support the laboratory-scale observations. This study aimed to evaluate the performance of a field-scale pulsed air-sparging system during a short-term pilot test and during long-term system operation. The air-sparging system consisted of 32 sparging points and had been previously operated in a continuous mode for two years before the field study was performed. The field study used instruments with continuous data logging capabilities to monitor the dynamic responses of groundwater and soil vapor parameters to air injection. The optimum pulsing frequency was based on the evidence that the hydrocarbon volatilization and oxygen dissolution rates dramatically dropped after the air-sparging system reached steady state. The short-term pilot test results indicated a substantial increase in hydrocarbon volatilization and biodegradation in pulsed operation. On the basis of the results of the pilottest, the air-sparging system was set to operate in a pulsed mode at an optimum pulsing frequency. Operation parameters were collected 2, 8, and 12 months after the start of the pulsed operation. The long-term monitoring results showed thatthe pulsed operation increased the average hydrocarbon removal rate (kg/day) by a factor of up to 3 as compared to the previous continuous operation. The pulsed air sparging has resulted in higher reduction rates of dissolved benzene, toluene, ethylbenzene, and xylenes (BTEX) than were observed during the continuous operation. Among BTEX, benzene's reduction rate was the highest during the pulsed air-sparging operation.

  18. Stress and physiological, behavioral and performance patterns of children under varied air ion levels

    NASA Astrophysics Data System (ADS)

    Fornof, K. T.; Gilbert, G. O.

    1988-12-01

    The possibility that individual differences in reactivity to stressors are a major factor underlying discordant results reported for air ion studies prompted an investigation of response patterns in school children under both normal indoor air ion levels and moderately increased negative air ion levels (4000±500/cm3). It was hypothesized that the impact of stressors is reduced with high negative air ionization, and that resultant changes in stress effects would be differentially exhibited according to the children's normal degree of stimulus reactivity. A counter-balanced, replicative, withinssubject design was selected, and the subjects were 12 environmentally sensitive, 1st 4th grade school children. In addition to monitoring stress effects on activity level, attention span, concentration to task and conceptual performance, measures were also made of urinary 5-hydroxyindole acetic acid levels and skin resistance response (SRR) to determine if changes extended to the physiological state. The cold water test was used to add physical stress and enable calculations of Lacey's autonomic lability scores (ALS) as indicators of individual reactivity. The results show main effects for air ions on both physiological parameters, with 48% less change in %SRR ( P<0.01) and 46% less change in urinary 5-HIAA levels ( P<0.055) during negative air ions, indicating increased stress tolerance. Strong interactive effects for ALS x air ion condition appeared, with high and low ALS children reacting oppositely to negative air ions in measures of skin resistance level ( P<0.01), wrist activity ( P<0.01) and digit span backwards ( P<0.004). Thus individual differences in autonomic reactivity and the presence or absence of stressors appear as critical elements for internal validity, and in preventing consequent skewed results from obscuring progress in air ion research.

  19. REMOVAL OF ORGANIC CCL CONTAMINANTS FROM DRINKING WATERS BY GAC, AIR STRIPPING, AND MEMBRANE PROCESSES

    EPA Science Inventory

    The 1996 amendments to the Safe Drinking Water Act (SWDA) require the US Environmental Protection Agency (USEPA) to establish a list of unregulated microbiological and chemical contaminants to aid in priority-setting for the Agency's drinking water program. This list, known as t...

  20. Copper contamination effects on hydrogen-air combustion under SCRAMJET (supersonic combustion ramjet) testing conditions

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Berry, G.F.

    1990-01-01

    Two forms of copper catalytic reactions (homogeneous and heterogeneous) in hydrogen flames were found in a literature survey. Hydrogen atoms in flames recombine into hydrogen molecules through catalytic reactions, and these reactions which affect the timing of the combustion process. Simulations of hydrogen flames with copper contamination were conducted by using a modified general chemical kinetics program (GCKP). Results show that reaction times of hydrogen flames are shortened by copper catalytic reactions, but ignition times are relatively insensitive to the reactions. The reduction of reaction time depends on the copper concentration, copper phase, particle size (if copper is in the condensed phase), and initial temperature and pressure. The higher the copper concentration of the smaller the particle, the larger the reduction in reaction time. For a supersonic hydrogen flame (Mach number = 4.4) contaminated with 200 ppm of gaseous copper species, the calculated reaction times are reduced by about 9%. Similar reductions in reaction time are also computed for heterogeneous copper contamination. Under scramjet testing conditions, the change of combustion timing appears to be tolerable (less than 5%) if the Mach number is lower than 3 or the copper contamination is less than 100 ppm. The higher rate the Mach number, the longer the reaction time and the larger the copper catalytic effects. 7 tabs., 8 figs., 34 refs.

  1. FORCED AIR VENTILATION FOR REMEDIATION OF UNSATURATED SOILS CONTAMINATED BY VOC

    EPA Science Inventory

    Parameters which were expected to control the removal process of VOCs from contaminated soil during the SVE operation were studied by means of numerical simulations and laboratory experiments in this project. Experimental results of SVE with soil columns in the laboratory indicat...

  2. Tracking Blood Lead and Zinc Protoporphyrin Levels in Andean Adults Working in a Lead Contaminated Environment

    PubMed Central

    Ortega, Fernando; Counter, S. Allen; Buchanan, Leo H.; Parra, Angelica Maria Coronel; Collaguaso, Maria Angela; Jacobs, Anthony B.

    2014-01-01

    The purpose of this study was to investigate current blood lead (PbB) and zinc protoporphyrin (ZPP) levels in adults presently living in environmentally Pb-contaminated Andean communities, and to compare the findings with the PbB and ZPP levels of Pb-exposed adult cohorts from the same study area tested between 1996 and 2007. Blood samples from 39 adults were measured for PbB and ZPP concentrations. The current mean PbB level (22.7 μg/dl) was significantly lower than the mean (37.9 μg/dl) of the initial 1996 cohort. PbB levels for the 1997, 1998, 2003, and 2006 cohorts were also significantly lower than the levels for the 1996 group. Elevated ZPP/heme ratios of 103.3, 128.4 and 134.2 μmol/mol were not significantly different for the 2006, 2007 and 2012 groups, indicating chronic Pb exposure. While ZPP levels of Andean Ecuadorian Pb-glazing workers have remained elevated, PbB levels declined. Pb exposure of the workers need to be continually monitored. PMID:24274152

  3. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, Terry C.; Fliermans, Carl B.

    1995-01-01

    An apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants; an oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth; withholding it periodicially forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene.

  4. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1995-01-24

    An apparatus and method are described for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants. An oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth. Withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene. 3 figures.

  5. Levels of asymmetry in Formica pratensis Retz. (Hymenoptera, Insecta) from a chronic metal-contaminated site

    SciTech Connect

    Rabitsch, W.B.

    1997-07-01

    Asymmetries of bilaterally symmetrical morphological traits in workers of the ant Formica pratensis Retzius were compared at sites with different levels of metal contamination and between mature and pre-mature colonies. Statistical analyses of the right-minus-left differences revealed that their distributions fit assumptions of fluctuating asymmetry (FA). No direct asymmetry or antisymmetry were present. Mean measurement error accounts for a third of the variation, but the maximum measurement error was 65%. Although significant differences of FA in ants were observed, the inconsistent results render uncovering a clear pattern difficult. Lead, cadmium, and zinc concentrations in the ants decreased with the distance from the contamination source, but no relation was found between FA and the heavy metal levels. Ants from the premature colonies were more asymmetrical than those from mature colonies but accumulated less metals. The use of asymmetry measures in ecotoxicology and biomonitoring is criticized, but should remain widely applicable if statistical assumptions are complemented by genetic and historical data.

  6. Oil contamination of fish in the North Sea. Determination of levels and identification of sources

    SciTech Connect

    Johnsen, S.; Restucci, R.; Klungsoyr, J.

    1996-12-31

    Two fish species, cod and haddock have been sampled from five different regions in the Norwegian sector of the North Sea, the Haltenbanken and the Barents Sea, Three of the five sampling areas were located in regions with no local oil or gas production, while the remaining two areas represented regions with high density of oil and gas production fields. A total of 25 specimen of each of the two fish species were collected, and liver (all samples) and muscle (10 samples from each group) were analyzed for the content of total hydrocarbons (THC), selected aromatic compounds (NPD and PAH) and bicyclic aliphatic decalines. The present paper outlines the results of liver samples analyses from four of the sampled regions, & northern North Sea region and the three reference regions Egersundbanken, Haltenbanken and the Barents Sea. In general, no significant difference was observed between the hydrocarbon levels within the sampled regions. The only observed exception was a moderate, but significant increase in decaline levels in haddock liver from the Northern North Sea region. The qualitative interpretation of the results showed that the sources of hydrocarbon contamination varied within the total sampling area. This observation indicates that the local discharge sources in areas with high petroleum production activity are the sources of hydrocarbons in fish from such areas. However, it was not possible to identify single discharges as a contamination source from the present results.

  7. Distribution pathways of hexachlorocyclohexane isomers in a soil-plant-air system. A case study with Cynara scolymus L. and Erica sp. plants grown in a contaminated site.

    PubMed

    Pereira, R Calvelo; Monterroso, C; Macías, F; Camps-Arbestain, M

    2008-09-01

    This study focuses on the main routes of distribution and accumulation of different hexachlorocyclohexane (HCH) isomers (mainly alpha-, beta-, gamma- and delta-HCH) in a soil-plant-air system. A field assay was carried out with two plant species, Cynara scolymus L. and Erica sp., which were planted either: (i) directly in the HCH-contaminated soil; or (ii) in pots filled with uncontaminated soil, which were placed in the HCH-contaminated soil. Both plant species accumulated HCH in their tissues, with relatively higher accumulation in above-ground biomass than in roots. The beta-HCH isomer was the main isomer in all plant tissues. Adsorption of HCH by the roots from contaminated soil (soil-->root pathway) and adsorption through the aerial biomass from either the surrounding air, following volatilization of the contaminant (soil-->air-->shoot pathway), and/or contact with air-suspended particles contaminated with HCH (soil particles-->shoot pathway) were the main mechanisms of accumulation. These results may have important implications for the use of plants for reducing the transfer of contaminants via the atmosphere.

  8. Functional gene array-based analysis of microbial community structure in groundwater with gradient of contaminant levels

    SciTech Connect

    Wu, Liyou; Van Nostrand, Joy; Schadt, Christopher Warren; Watson, David B; Jardine, Philip M; Palumbo, Anthony Vito; Hazen, Terry; Zhou, Jizhong

    2009-04-01

    To understand how contaminants affect microbial community diversity, heterogeneity, and functional structure, six groundwater monitoring wells from the Field Research Center of the U.S. Department of Energy Environmental Remediation Science Program (ERSP; Oak Ridge, TN), with a wide range of pH, nitrate, and heavy metal contamination were investigated. DNA from the groundwater community was analyzed with a functional gene array containing 2006 probes to detect genes involved in metal resistance, sulfate reduction, organic contaminant degradation, and carbon and nitrogen cycling. Microbial diversity decreased in relation to the contamination levels of the wells. Highly contaminated wells had lower gene diversity but greater signal intensity than the pristine well. The microbial composition was heterogeneous, with 17?70% overlap between different wells. Metal-resistant and metal-reducing microorganisms were detected in both contaminated and pristine wells, suggesting the potential for successful bioremediation of metal-contaminated groundwaters. In addition, results of Mantel tests and canonical correspondence analysis indicate that nitrate, sulfate, pH, uranium, and technetium have a significant (p < 0.05) effect on microbial community structure. This study provides an overall picture of microbial community structure in contaminated environments with functional gene arrays by showing that diversity and heterogeneity can vary greatly in relation to contamination.

  9. Functional gene array-based analysis of microbial community structure in groundwaters with a gradient of contaminant levels

    SciTech Connect

    Waldron, P.J.; Wu, L.; Van Nostrand, J.D.; Schadt, C.W.; Watson, D.B.; Jardine, P.M.; Palumbo, A.V.; Hazen, T.C.; Zhou, J.

    2009-06-15

    To understand how contaminants affect microbial community diversity, heterogeneity, and functional structure, six groundwater monitoring wells from the Field Research Center of the U.S. Department of Energy Environmental Remediation Science Program (ERSP; Oak Ridge, TN), with a wide range of pH, nitrate, and heavy metal contamination were investigated. DNA from the groundwater community was analyzed with a functional gene array containing 2006 probes to detect genes involved in metal resistance, sulfate reduction, organic contaminant degradation, and carbon and nitrogen cycling. Microbial diversity decreased in relation to the contamination levels of the wells. Highly contaminated wells had lower gene diversity but greater signal intensity than the pristine well. The microbial composition was heterogeneous, with 17-70% overlap between different wells. Metal-resistant and metal-reducing microorganisms were detected in both contaminated and pristine wells, suggesting the potential for successful bioremediation of metal-contaminated groundwaters. In addition, results of Mantel tests and canonical correspondence analysis indicate that nitrate, sulfate, pH, uranium, and technetium have a significant (p < 0.05) effect on microbial community structure. This study provides an overall picture of microbial community structure in contaminated environments with functional gene arrays by showing that diversity and heterogeneity can vary greatly in relation to contamination.

  10. Functional gene array-based analysis of microbial community structure in groundwaters with a gradient of contaminant levels.

    PubMed

    Waldron, Patricia J; Wu, Liyou; Van Nostrand, Joy D; Schadt, Chris W; He, Zhili; Watson, David B; Jardine, Philip M; Palumbo, Anthony V; Hazen, Terry C; Zhou, Jizhong

    2009-05-15

    To understand how contaminants affect microbial community diversity, heterogeneity, and functional structure, six groundwater monitoring wells from the Field Research Center of the U.S. Department of Energy Environmental Remediation Science Program (ERSP; Oak Ridge, TN), with a wide range of pH, titrate, and heavy metal contamination were investigated. DNA from the groundwater community was analyzed with a functional gene array containing 2006 probes to detect genes involved in metal resistance, sulfate reduction, organic contaminant degradation, and carbon and nitrogen cycling. Microbial diversity decreased in relation to the contamination levels of the wells. Highly contaminated wells had lower gene diversity but greater signal intensity than the pristine well. The microbial composition was heterogeneous, with 17-70% overlap between differentwells. Metal-resistant and metal-reducing microorganisms were detected in both contaminated and pristine wells, suggesting the potential for successful bioremediation of metal-contaminated groundwaters. In addition, results of Mantel tests and canonical correspondence analysis indicate that nitrate, sulfate, pH, uranium, and technetium have a significant (p < 0.05) effect on microbial community structure. This study provides an overall picture of microbial community structure in contaminated environments with functional gene arrays by showing that diversity and heterogeneity can vary greatly in relation to contamination.

  11. In-situ determination of radionuclide levels in facilities to be decommissioned using the allowable residual contamination level method

    SciTech Connect

    Arthur, R.J.; Haggard, D.L.

    1989-07-01

    This feasibility study resulted in verification of a direct and two alternate indirect techniques for making in-situ determinations of {sup 90}Sr and other radionuclide levels in a Hanford facility to be decommissioned that was evaluated using the Allowable Residual Contamination Level (ARCL) method. The ARCL method is used to determine the extent of decontamination that will be required before a facility can be decommissioned. A sump in the 1608F Building was chosen for the feasibility study. Hanford decommissioning personnel had previously taken 79 concrete and surface scale samples from the building to be analyzed by radiochemical analysis. The results of the radiochemical analyses compare favorably with the values derived by the in-situ methods presented in this report. Results obtained using a portable spectrometer and thermoluminescent dosimeters (TLDs) were both very close to the radiochemistry results. Surface {sup 90}Sr levels detected on the sump floor were 550 pCi/cm{sup 2} using the spectrometer system and 780 pCi/cm{sup 2} using the TLD data. This compares favorably with the levels determined by radiochemical analyses (i.e., 230 to 730 pCi/cm{sup 2}). Surface {sup 90}Sr levels detected on the sump wall ranged between 10 and 80 pCi/cm{sup 2} using the spectrometer system, compared with a conservative 200 pCi/cm{sup 2} using the TLD data. The radiochemical results ranged between 19 and 77 pCi/cm{sup 2} for the four samples taken from the wall at indeterminate locations. 17 refs., 15 figs., 2 tabs.

  12. Linking source and effect: resuspended soil lead, air lead, and children's blood lead levels in Detroit, Michigan.

    PubMed

    Zahran, Sammy; Laidlaw, Mark A S; McElmurry, Shawn P; Filippelli, Gabriel M; Taylor, Mark

    2013-03-19

    This study evaluates atmospheric concentrations of soil and Pb aerosols, and blood lead levels (BLLs) in 367839 children (ages 0-10) in Detroit, Michigan from 2001 to 2009 to test a hypothesized soil → air dust → child pathway of contemporary Pb risk. Atmospheric soil and Pb show near-identical seasonal properties that match seasonal variation in children's BLLs. Resuspended soil appears to be a significant underlying source of atmospheric Pb. A 1% increase in the amount of resuspended soil results in a 0.39% increase in the concentration of Pb in the atmosphere (95% CI, 0.28 to 0.50%). In turn, atmospheric Pb significantly explains age-dependent variation in child BLLs. Other things held equal, a change of 0.0069 μg/m(3) in atmospheric Pb increases BLL of a child 1 year of age by 10%, while approximately 3 times the concentration of Pb in air (0.023 μg/m(3)) is required to induce the same increase in BLL of a child 7 years of age. Similarly, a 0.0069 μg/m(3) change in air Pb increases the odds of a child <1 year of age having a BLL ≥ 5 μg/dL by a multiplicative factor of 1.32 (95% CI, 1.26 to 1.37). Overall, the resuspension of Pb contaminated soil explains observed seasonal variation in child BLLs.

  13. Biofiltration of benzene contaminated air streams using compost-activated carbon filter media

    SciTech Connect

    Zhu, L.; Kocher, W.M.; Abumaizar, R.J.

    1998-12-31

    Three laboratory-scale biofilter columns were operated for 81 days to investigate the removal of benzene from a waste gas stream. The columns contain a mixture of yard waste and sludge compost as biomedia. Different amounts of granular activated carbon (GAC) are mixed with the compost in two of the three columns to evaluate the extent to which biofilter performance can be enhanced. The effects of different operating conditions on the performance of the removal of benzene from air were evaluated. More than 90% removal efficiency was observed for an influent benzene concentration of about 75 ppm and an air flow rate of 0.3 L/min. in all 3 columns under steady-state conditions. Under most cases of shock loading conditions, such as a sudden increase in the air flow rate, or the benzene concentration in the influent, the biofilters containing GAC provided higher removal efficiencies and more stable operation than the biofilter containing compost only.

  14. Effects of decontamination at varying contamination levels of Campylobacter jejuni on broiler meat.

    PubMed

    Boysen, L; Wechter, N S; Rosenquist, H

    2013-05-01

    When assessing effects of decontamination techniques on counts of Campylobacter spp. on broiler meat, it is essential that the results reflect the variations that may exist. Decontamination studies often use high inoculation levels (10(7) to 10(8) cfu) and one or few strains of Campylobacter jejuni, thereby restricting the results to reflect only a limited part of the true situation. This study presents results from physical and chemical decontamination of broiler meat medallions using different strains and different initial concentrations of C. jejuni. For 3 strains of C. jejuni, mean log reductions obtained by freezing at -20°C for 7 d was significantly higher for an initial concentration of 10(7) cfu/sample on the meat compared with an initial concentration of 10(3) cfu/sample. For freezing at -20°C for 24 h or application of 6% tartaric acid and subsequent storage for 24 h, no statistically significant difference in reductions was found for initial concentrations ranging from 10(3) to 10(7) cfu per sample. The mean log reductions obtained by all techniques were strongly dependent on the strain tested. The results reveal that reductions obtained with high inoculation levels of C. jejuni (10(7) cfu/sample) or single or few strains of the species (or both) should not be interpreted as a generic result for the species. If inoculation studies cannot be replaced by investigations of naturally contaminated meat, we advise using a mixture of strains found in the production environment at levels as close as possible to the natural contamination level.

  15. Community perspectives on the risk of indoor air pollution arising from contaminated groundwater.

    PubMed

    Johnston, Jill E; Kramer, Amanda J; Gibson, Jacqueline MacDonald

    2015-05-01

    The migration of volatile contaminants into overlying buildings, known as vapor intrusion, is a health concern for people living above contaminated groundwater. As public health and environmental agencies develop protocols to evaluate vapor intrusion exposure, little attention has been paid to the experiences and opinions of communities likely to be affected by vapor intrusion. Using a community-driven research approach and qualitative interviews, we explored community perspectives on the vapor intrusion pathway and the perceived impact on community health and well-being among neighbors living atop a large, shallow-chlorinated solvent plume in San Antonio, TX. Most participants associated vapor intrusion with health risks, expressing concern about the unavoidable and uncontrollable nature of their exposure. Few were satisfied with the responsiveness of public officials. Above all, participants wanted more accurate, transparent information and additional independent scientific investigations.

  16. Community perspectives on the risk of indoor air pollution arising from contaminated groundwater.

    PubMed

    Johnston, Jill E; Kramer, Amanda J; Gibson, Jacqueline MacDonald

    2015-05-01

    The migration of volatile contaminants into overlying buildings, known as vapor intrusion, is a health concern for people living above contaminated groundwater. As public health and environmental agencies develop protocols to evaluate vapor intrusion exposure, little attention has been paid to the experiences and opinions of communities likely to be affected by vapor intrusion. Using a community-driven research approach and qualitative interviews, we explored community perspectives on the vapor intrusion pathway and the perceived impact on community health and well-being among neighbors living atop a large, shallow-chlorinated solvent plume in San Antonio, TX. Most participants associated vapor intrusion with health risks, expressing concern about the unavoidable and uncontrollable nature of their exposure. Few were satisfied with the responsiveness of public officials. Above all, participants wanted more accurate, transparent information and additional independent scientific investigations. PMID:25815742

  17. Relationship Between Indoor Air Pollutant Levels and Residential Environment in Children With Atopic Dermatitis

    PubMed Central

    Lee, Jung Hyun; Lee, Ho Seok; Park, Mi Ran; Lee, Sang Woon; Kim, Eun Hye; Cho, Joong Bum; Kim, Jihyun; Han, Youngshin; Jung, Kweon; Cheong, Hae Kwan; Lee, Sang Il

    2014-01-01

    Purpose This study was aimed to investigate the relationship between indoor air pollutant levels and residential environment in children with atopic dermatitis (AD) living in Seoul. Methods A total of 150 children with AD were included. Residential environment was assessed by questionnaires which were completed by their parents. To evaluate the level of exposure to the indoor air pollutants, concentrations of the indoor air pollutants including particulate matter with diameter less than 10 µm (PM10), formaldehyde, carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NO2), Total Volatile Organic Compound (TVOC), benzene, toluene, ethyl-benzene, xylene, styrene, bacterial aerosols, and airborne fungi were measured. Results A significant difference was exhibited in the levels of PM10 in case of visible fungus on the walls (P=0.047). There was relationship between the construction year of the house, moving to a newly constructed building within 1 year and formaldehyde level. With the use of artificial air freshener, the differences were found in the concentrations of TVOC (P=0.003), benzene (P=0.015), toluene (P=0.012) and ethyl-benzene (P=0.027). The concentration of xylene was significantly high when oil was used as heating fuel (P=0.015). Styrene exhibited differences depending on building type and its concentrations were significantly high in a residential and commercial complex building (P=0.005). The indoor concentration of bacterial aerosols was significantly low with the use of air cleaner (P=0.045). High NO2, benzene concentrations were present in case of almost no ventilation (P=0.028 and P=0.028, respectively). Conclusions Individual residential environments are closely related with the levels of the indoor air pollutants. To alleviate AD symptoms, simple questions about residential environments such as visible fungus on the walls and the use of artificial air freshener are helpful to assess the possibility of increased indoor air pollutant levels

  18. Simulation of ground-water flow and application to the design of a contaminant removal system, Loring Air Force Base, Maine

    USGS Publications Warehouse

    Starn, J.J.

    1997-01-01

    The fractured-bedrock aquifer underlying the former Fire Training Area at Loring Air Force Base, Maine, has been contaminated with petroleum products as a result of fire training activities. A numerical model of the ground-water-flow system near the Fire Training Area was developed to provide information for the design and operation of a contaminant removal system. The goals of the simulation modeling were to (1) determine the maximum pumping rate that could be sustained, giventhe constraint that water levels not rise above a specified altitude, and (2) determine the effect of seasonal variation in recharge on the ability of a transient pumping scenario to capture contaminants. A steady-state simulation model of ground-water flow was used to determine the optimal pumping rate at the site. The optimal pumping rate was 8,570 ft3/d (44 gal/min). Monthly recharge rates wereestimated for use in a transient simulation model. During a typical year, most recharge probably occurs during two periods-one during snowmelt in early spring and another, possibly less significant period, during the late fall. The transient response of the water table to 8.5 inches of recharge in April, 2 inches of recharge in October, and 0.25 inches of recharge per month for each remaining month wassimulated. Fluctuations in ground-water levels caused by simulated seasonal variation of recharge would have minimal effect on the operation of thecontaminant removal system because the system is not pumped when recharge is lowest, ground-water velocities are lowest, and ground-water flow past the trench is minimal.

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

    PubMed

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

    2016-02-01

    Honey bees are exposed to a variety of environmental factors that impact their health, including nutritional stress, pathogens, and pesticides. In particular, there has been increasing evidence that sublethal exposure to pesticides can cause subtle, yet important effects on honey bee health and behavior. Here, we add to this body of knowledge by presenting data on bee-collected pollen containing sublethal levels of cyhalothrin, a pyrethroid insecticide, which, when fed to young honey bees, resulted in significant changes in lifespan, nutritional physiology,and behavior. For the first time, we show that when young, nest-aged bees are presented with pollen containing field-relevant levels of cyhalothrin, they reduce their consumption of contaminated pollen. This indicates that, at least for some chemicals, young bees are able to detect contamination in pollen and change their behavioral response, even if the contamination levels do not prevent foraging honey bees from collecting the contaminated pollen. PMID:26476556

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

    PubMed

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

    2016-02-01

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

  1. Nonlinear Least-Squares Based Method for Identifying and Quantifying Single and Mixed Contaminants in Air with an Electronic Nose

    PubMed Central

    Zhou, Hanying; Homer, Margie L.; Shevade, Abhijit V.; Ryan, Margaret A.

    2006-01-01

    The Jet Propulsion Laboratory has recently developed and built an electronic nose (ENose) using a polymer-carbon composite sensing array. This ENose is designed to be used for air quality monitoring in an enclosed space, and is designed to detect, identify and quantify common contaminants at concentrations in the parts-per-million range. Its capabilities were demonstrated in an experiment aboard the National Aeronautics and Space Administration's Space Shuttle Flight STS-95. This paper describes a modified nonlinear least-squares based algorithm developed to analyze data taken by the ENose, and its performance for the identification and quantification of single gases and binary mixtures of twelve target analytes in clean air. Results from laboratory-controlled events demonstrate the effectiveness of the algorithm to identify and quantify a gas event if concentration exceeds the ENose detection threshold. Results from the flight test demonstrate that the algorithm correctly identifies and quantifies all registered events (planned or unplanned, as singles or mixtures) with no false positives and no inconsistencies with the logged events and the independent analysis of air samples.

  2. HYGIENE-AND FOOD-RELATED BEHAVIORS ASSOCIATED WITH BLOOD LEAD LEVELS OF YOUNG CHILDREN FROM LEAD-CONTAMINATED HOMES

    EPA Science Inventory

    Exposures associated with blood lead levels greater than 40 ug/dl in young children who live in lead-contaminated homes have been well documented. As the action level for lead is reduced, activities that contribute to lower levels of lead exposure must be identified. A child's ea...

  3. Corticosterone levels in relation to trace element contamination along an urbanization gradient in the common blackbird (Turdus merula).

    PubMed

    Meillère, Alizée; Brischoux, François; Bustamante, Paco; Michaud, Bruno; Parenteau, Charline; Marciau, Coline; Angelier, Frédéric

    2016-10-01

    In a rapidly urbanizing world, trace element pollution may represent a threat to human health and wildlife, and it is therefore crucial to assess both exposition levels and associated effects of trace element contamination on urban vertebrates. In this study, we investigated the impact of urbanization on trace element contamination and stress physiology in a wild bird species, the common blackbird (Turdus merula), along an urbanization gradient (from rural to moderately urbanized areas). Specifically, we described the contamination levels of blackbirds by 4 non-essential (Ag, Cd, Hg, Pb) and 9 essential trace elements (As, Co, Cr, Cu, Fe, Mn, Ni, Se, Zn), and explored the putative disrupting effects of the non-essential element contamination on corticosterone levels (a hormonal proxy for environmental challenges). We found that non-essential trace element burden (Cd and Pb specifically) increased with increasing urbanization, indicating a significant trace element contamination even in medium sized cities and suburban areas. Interestingly, the increased feather non-essential trace element concentrations were also associated with elevated feather corticosterone levels, suggesting that urbanization probably constrains birds and that this effect may be mediated by trace element contamination. Future experimental studies are now required to disentangle the influence of multiple urban-related constraints on corticosterone levels and to specifically test the influence of each of these trace elements on corticosterone secretion.

  4. Corticosterone levels in relation to trace element contamination along an urbanization gradient in the common blackbird (Turdus merula).

    PubMed

    Meillère, Alizée; Brischoux, François; Bustamante, Paco; Michaud, Bruno; Parenteau, Charline; Marciau, Coline; Angelier, Frédéric

    2016-10-01

    In a rapidly urbanizing world, trace element pollution may represent a threat to human health and wildlife, and it is therefore crucial to assess both exposition levels and associated effects of trace element contamination on urban vertebrates. In this study, we investigated the impact of urbanization on trace element contamination and stress physiology in a wild bird species, the common blackbird (Turdus merula), along an urbanization gradient (from rural to moderately urbanized areas). Specifically, we described the contamination levels of blackbirds by 4 non-essential (Ag, Cd, Hg, Pb) and 9 essential trace elements (As, Co, Cr, Cu, Fe, Mn, Ni, Se, Zn), and explored the putative disrupting effects of the non-essential element contamination on corticosterone levels (a hormonal proxy for environmental challenges). We found that non-essential trace element burden (Cd and Pb specifically) increased with increasing urbanization, indicating a significant trace element contamination even in medium sized cities and suburban areas. Interestingly, the increased feather non-essential trace element concentrations were also associated with elevated feather corticosterone levels, suggesting that urbanization probably constrains birds and that this effect may be mediated by trace element contamination. Future experimental studies are now required to disentangle the influence of multiple urban-related constraints on corticosterone levels and to specifically test the influence of each of these trace elements on corticosterone secretion. PMID:27213675

  5. A RAPID DNA EXTRACTION METHOD FOR PCR IDENTIFICATION OF FUNGAL INDOOR AIR CONTAMINANTS

    EPA Science Inventory

    Following air sampling, fungal DNA needs to be extracted and purified to a state suitable for laboratory use. Our laboratory has developed a simple method of extraction and purification of fungal DNA appropriate for enzymatic manipulation and polymerase chain reaction (PCR) appli...

  6. PULSED AIR SPARGING IN AQUIFERS CONTAMINATED WITH DENSE NONAQUEOUS PHASE LIQUIDS

    EPA Science Inventory

    Air sparging was evaluated for remediation of tetrachloroethylene (PCE) present as dense nonaqueous phase liquid (DNAPL) in aquifers. A two-dimensional laboratory tank with a transparent front wall allowed for visual observation of DNAPL mobilization. A DNAPL zone 50 cm high was ...

  7. EMERGING TECHNOLOGY REPORT: DESTRUCTION OF ORGANIC CONTAMINANTS IN AIR USING ADVANCED ULTRAVIOLET FLASHLAMPS

    EPA Science Inventory

    This paper describes a new process for photo-oxidation of volatile organic compounds (VOCs) in air using an advanced ultraviolet source, a Purus xenon flashlamp. The flashlamps have greater output at 200-250 nm than medium-pressure mercury lamps at the same power and therefore ca...

  8. Influence of contaminated drinking water on perfluoroalkyl acid levels in human serum--A case study from Uppsala, Sweden.

    PubMed

    Gyllenhammar, Irina; Berger, Urs; Sundström, Maria; McCleaf, Philip; Eurén, Karin; Eriksson, Sara; Ahlgren, Sven; Lignell, Sanna; Aune, Marie; Kotova, Natalia; Glynn, Anders

    2015-07-01

    In 2012 a contamination of drinking water with perfluoroalkyl acids (PFAAs) was uncovered in the City of Uppsala, Sweden. The aim of the present study was to determine how these substances have been distributed from the contamination source through the groundwater to the drinking water and how the drinking water exposure has influenced the levels of PFAAs in humans over time. The results show that PFAA levels in groundwater measured 2012-2014 decreased downstream from the point source, although high ΣPFAA levels (>100ng/L) were still found several kilometers from the point source in the Uppsala aquifer. The usage of aqueous film forming fire-fighting foams (AFFF) at a military airport in the north of the city is probably an important contamination source. Computer simulation of the distribution of PFAA-contaminated drinking water throughout the City using a hydraulic model of the pipeline network suggested that consumers in the western and southern parts of Uppsala have received most of the contaminated drinking water. PFAA levels in blood serum from 297 young women from Uppsala County, Sweden, sampled during 1996-1999 and 2008-2011 were analyzed. Significantly higher concentrations of perfluorobutane sulfonic acid (PFBS) and perfluorohexane sulfonic acid (PFHxS) were found among women who lived in districts modeled to have received contaminated drinking water compared to unaffected districts both in 1996-1999 and 2008-2011, indicating that the contamination was already present in the late 1990s. Isomer-specific analysis of PFHxS in serum showed that women in districts with contaminated drinking water also had an increased percentage of branched isomers. Our results further indicate that exposure via contaminated drinking water was the driving factor behind the earlier reported increasing temporal trends of PFBS and PFHxS in blood serum from young women in Uppsala.

  9. Microbial counts and particulate matter levels in roadside air samples under skytrain stations, Bangkok, Thailand.

    PubMed

    Luksamijarulkul, Pipat; Kongtip, Pornpimol

    2010-05-01

    In conditions with heavy traffic and crowds of people on roadside areas under skytrain stations in Bangkok, the natural air ventilation may be insufficient and air quality may be poor. A study of 350 air samples collected from the roadside, under skytrain stations in Bangkok, was carried out to assess microbial counts (210 air samples) and particulate matter (PM10) levels (140 samples). The results reveal the mean +/- standard deviation bacterial counts and fungal counts were 406.8 +/- 302.7 cfu/m3 and 128.9 +/- 89.7 cfu/m3, respectively. The PM10 level was 186.1 +/- 188.1 microg/m3. When compared to recommended levels, 4.8% of air samples (10/210 samples) had bacterial counts more than recommended levels (> 1,000 cfu/ m3) and 27.1% (38/140 samples) had PM10 levels more than recommended levels (> 120 microg/m3). These may affect human health, especially of street venders who spend most of their working time in these areas. PMID:20578558

  10. Microbial counts and particulate matter levels in roadside air samples under skytrain stations, Bangkok, Thailand.

    PubMed

    Luksamijarulkul, Pipat; Kongtip, Pornpimol

    2010-05-01

    In conditions with heavy traffic and crowds of people on roadside areas under skytrain stations in Bangkok, the natural air ventilation may be insufficient and air quality may be poor. A study of 350 air samples collected from the roadside, under skytrain stations in Bangkok, was carried out to assess microbial counts (210 air samples) and particulate matter (PM10) levels (140 samples). The results reveal the mean +/- standard deviation bacterial counts and fungal counts were 406.8 +/- 302.7 cfu/m3 and 128.9 +/- 89.7 cfu/m3, respectively. The PM10 level was 186.1 +/- 188.1 microg/m3. When compared to recommended levels, 4.8% of air samples (10/210 samples) had bacterial counts more than recommended levels (> 1,000 cfu/ m3) and 27.1% (38/140 samples) had PM10 levels more than recommended levels (> 120 microg/m3). These may affect human health, especially of street venders who spend most of their working time in these areas.

  11. Assessment of contaminant levels and trophic relations at a World Heritage Site by measurements in a characteristic shorebird species

    SciTech Connect

    Schwemmer, Philipp; Covaci, Adrian; Das, Krishna; Lepoint, Gilles; Adler, Sven; Garthe, Stefan

    2015-01-15

    The River Elbe is responsible for influxes of contaminants into the Wadden Sea World Heritage Site. We investigated levels of polychlorinated biphenyls (PCBs), oxychlordane (OxC), hexachlorobenzene (HCB), hexachlorocyclohexanes (α-, β-, γ-HCHs), dichlorodiphenyltrichloroethane (DDT) and its metabolites, and polybrominated diphenyl ethers (PBDEs) in blood and feathers from Eurasian oystercatchers (Haematopus ostralegus; n=28) at the Elbe and compared it with a non-riverine site about 90 km further north. (1) Mean levels of all contaminants in feathers and serum were significantly higher at the river (∑PCBs: 27.6 ng/g feather, 37.0 ng/ml serum; ∑DDTs: 5.3 ng/g feather, 4.4 ng/ml serum) compared with the non-riverine site (∑PCBs: 6.5 ng/g feather, 1.2 ng/ml serum; ∑DDTs: 1.4 ng/g feather, 0.5 ng/ml serum). Mean ∑HCH and HCB levels were <1.8 ng/g in feather and <1.8 ng/ml in serum at both sites. (2) Levels of most detectable compounds in serum and feathers were significantly related, but levels were not consistently higher in either tissue. (3) There was no significant relationship between trophic level in individual oystercatchers (expressed as δ15N) or the degree of terrestrial feeding (expressed as δ13C) and contaminant loads. (4) PBDEs were not detected in significant amounts at either site. The results of this study indicate that the outflow from one of Europe′s largest river systems is associated with significant historical contamination, reflected by the accumulation of contaminants in body tissues in a coastal benthivore predator. - Highlights: • Contaminants in Oystercatchers from the Elbe river and a non-riverine site were measured. • Mean levels of contaminants were higher at the river than at the non-riverine site. • Levels of most contaminants in serum and feathers were significantly related. • No relationship between trophic level (δ15N) and contaminant level was found. • One of Europe′s largest river systems is associated

  12. Laboratory Rodent Diets Contain Toxic Levels of Environmental Contaminants: Implications for Regulatory Tests

    PubMed Central

    Rocque, Louis-Marie; Spiroux de Vendômois, Joël; Séralini, Gilles-Eric

    2015-01-01

    The quality of diets in rodent feeding trials is crucial. We describe the contamination with environmental pollutants of 13 laboratory rodent diets from 5 continents. Measurements were performed using accredited methodologies. All diets were contaminated with pesticides (1-6 out of 262 measured), heavy metals (2-3 out of 4, mostly lead and cadmium), PCDD/Fs (1-13 out of 17) and PCBs (5-15 out of 18). Out of 22 GMOs tested for, Roundup-tolerant GMOs were the most frequently detected, constituting up to 48% of the diet. The main pesticide detected was Roundup, with residues of glyphosate and AMPA in 9 of the 13 diets, up to 370 ppb. The levels correlated with the amount of Roundup-tolerant GMOs. Toxic effects of these pollutants on liver, neurodevelopment, and reproduction are documented. The sum of the hazard quotients of the pollutants in the diets (an estimator of risk with a threshold of 1) varied from 15.8 to 40.5. Thus the chronic consumption of these diets can be considered at risk. Efforts toward safer diets will improve the reliability of toxicity tests in biomedical research and regulatory toxicology. PMID:26133768

  13. Laboratory Rodent Diets Contain Toxic Levels of Environmental Contaminants: Implications for Regulatory Tests.

    PubMed

    Mesnage, Robin; Defarge, Nicolas; Rocque, Louis-Marie; Spiroux de Vendômois, Joël; Séralini, Gilles-Eric

    2015-01-01

    The quality of diets in rodent feeding trials is crucial. We describe the contamination with environmental pollutants of 13 laboratory rodent diets from 5 continents. Measurements were performed using accredited methodologies. All diets were contaminated with pesticides (1-6 out of 262 measured), heavy metals (2-3 out of 4, mostly lead and cadmium), PCDD/Fs (1-13 out of 17) and PCBs (5-15 out of 18). Out of 22 GMOs tested for, Roundup-tolerant GMOs were the most frequently detected, constituting up to 48% of the diet. The main pesticide detected was Roundup, with residues of glyphosate and AMPA in 9 of the 13 diets, up to 370 ppb. The levels correlated with the amount of Roundup-tolerant GMOs. Toxic effects of these pollutants on liver, neurodevelopment, and reproduction are documented. The sum of the hazard quotients of the pollutants in the diets (an estimator of risk with a threshold of 1) varied from 15.8 to 40.5. Thus the chronic consumption of these diets can be considered at risk. Efforts toward safer diets will improve the reliability of toxicity tests in biomedical research and regulatory toxicology. PMID:26133768

  14. Laboratory Rodent Diets Contain Toxic Levels of Environmental Contaminants: Implications for Regulatory Tests.

    PubMed

    Mesnage, Robin; Defarge, Nicolas; Rocque, Louis-Marie; Spiroux de Vendômois, Joël; Séralini, Gilles-Eric

    2015-01-01

    The quality of diets in rodent feeding trials is crucial. We describe the contamination with environmental pollutants of 13 laboratory rodent diets from 5 continents. Measurements were performed using accredited methodologies. All diets were contaminated with pesticides (1-6 out of 262 measured), heavy metals (2-3 out of 4, mostly lead and cadmium), PCDD/Fs (1-13 out of 17) and PCBs (5-15 out of 18). Out of 22 GMOs tested for, Roundup-tolerant GMOs were the most frequently detected, constituting up to 48% of the diet. The main pesticide detected was Roundup, with residues of glyphosate and AMPA in 9 of the 13 diets, up to 370 ppb. The levels correlated with the amount of Roundup-tolerant GMOs. Toxic effects of these pollutants on liver, neurodevelopment, and reproduction are documented. The sum of the hazard quotients of the pollutants in the diets (an estimator of risk with a threshold of 1) varied from 15.8 to 40.5. Thus the chronic consumption of these diets can be considered at risk. Efforts toward safer diets will improve the reliability of toxicity tests in biomedical research and regulatory toxicology.

  15. Allowable residual contamination levels of radionuclides in soil from pathway analysis

    SciTech Connect

    Nyquist, J.E.; Baes, C.F. III

    1987-01-01

    The uncertainty regarding radionuclide distributions among Remedial Action Program (RAP) sites and long-term decommissioning and closure options for these sites requires a flexible approach capable of handling different levels of contamination, dose limits, and closure scenarios. We identified a commercially available pathway analysis model, DECOM, which had been used previously in support of remedial activities involving contaminated soil at the Savannah River Plant. The DECOM computer code, which estimates concentrations of radionuclides uniformly distributed in soil that correspond to an annual effective dose equivalent, is written in BASIC and runs on an IBM PC or compatible microcomputer. We obtained the latest version of DECOM and modified it to make it more user friendly and applicable to the Oak Ridge National Laboratory (ORNL) RAP. Some modifications involved changes in default parameters or changes in models based on approaches used by the EPA in regulating remedial actions for hazardous substances. We created a version of DECOM as a LOTUS spreadsheet, using the same models as the BASIC version of DECOM. We discuss the specific modeling approaches taken, the regulatory framework that guided our efforts, the strengths and limitations of each approach, and areas for improvement. We also demonstrate how the LOTUS version of DECOM can be applied to specific problems that may be encountered during ORNL RAP activities. 18 refs., 2 figs., 3 tabs.

  16. Evaluation of internal contamination levels after a radiological dispersal device incident using portal monitors.

    PubMed

    Palmer, R C; Hertel, N E; Ansari, A; Manger, R P; Freibert, E J

    2012-08-01

    Following a radioactive dispersal device (RDD) incident, it may be necessary to evaluate the internal contamination levels of a large number of potentially affected individuals to determine if immediate medical follow-up is necessary. Since the current laboratory capacity to screen for internal contamination is limited, rapid field screening methods can be useful in prioritising individuals. This study evaluated the suitability of a radiation portal monitor for such screening. A model of the portal monitor was created for use with models of six anthropomorphic phantoms in Monte Carlo N-Particle Transport Code Version 5 (MCNP) X-5 Monte Carlo Team (MCNP-A General Monte Carlo N-Particle Transport Code Version 5. LA-CP-03-0245. Vol. 2. Los Alamos National Laboratory, 2004.). The count rates of the portal monitor were simulated for inhalation and ingestion of likely radionuclides from an RDD for each of the phantoms. The time-dependant organ concentrations of the radionuclides were determined using Dose and Risk Calculation Software Eckerman, Leggett, Cristy, Nelson, Ryman, Sjoreen and Ward (Dose and Risk Calculation Software Ver. 8.4. ORNL/TM-2001/190. Oak Ridge National Laboratory, 2006.). Portal monitor count rates corresponding to a committed effective dose E(50) of 10 mSv are reported.

  17. Treatment of Navy landfill leachate contaminated with low levels of priority pollutants. Final report, Jun 89-Mar 90

    SciTech Connect

    Jue, C.; Regan, R.W.

    1991-10-01

    This report discusses remediation of landfill leachate and contaminated ground water at selected Naval facilities. A conventional treatment train (air stripping, ion exchange, and carbon adsorption) was used to illustrate the treatment potential for a diluted leachate at Naval Weapons Station, Seal Beach. The treatment removed specified organics to below 29 ppb and specified metals to below California's drinking water standards. Available costs for conventional and innovative treatment trains were considered. Treatment technologies include oil water separators, activated sludge, trickling filter, powdered activated carbon, neutralization, oxidation reduction, precipitation/floculation/sedimentation, and air stripping.

  18. BOREAS AFM-5 Level-2 Upper Air Network Standard Pressure Level Data

    NASA Technical Reports Server (NTRS)

    Barr, Alan; Hrynkiw, Charmaine; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS AFM-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing AES aerological network, both temporally and spatially. This data set includes basic upper-air parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure from data collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  19. [Study on feasible emission control level of air pollutions for cement industry ].

    PubMed

    Ren, Chun; Jiang, Mei; Zou, Lan; Li, Xiao-qian; Wei, Yu-xia; Zhao, Guo-hua; Zhang, Guo-ning

    2014-09-01

    The revised National Emission Standard of Air Pollutions for Cement Industry has been issued, which will be effective for the new enterprises and the existing enterprises on Mar. 1st, 2014 and July 1st, 2015, respectively. In the process of revision, the key technical issues on determination of standard limits was how to determine the feasible emission control level of air pollutions. Feasible emission control requirements were put forward, according to air pollutants emission, technologies, environmental management requirements and foreign standards, etc. The main contents of the revised standard include expanding the scope of application, increasing the pollutants, improving the particulate and NO emissions control level, and increasing special emission limits applied to key areas of air pollutants. The standard will become the gripper of pollution prevention, total emission reduction, structural adjustment and optimization of the layout, and will promote scientific and technical progression for the cement industry.

  20. A new dose model for assessment of health risk due to contaminants in air.

    PubMed

    Rajkumar, T; Guesgen, H W; Robinson, S; Fisher, G W

    2000-01-01

    The problem of making quantitative assessments of the risks associated with human exposure to toxic contaminants in the environment is a pressing one. This study demonstrates the capability of a new computational technique involving the use of fuzzy logic and neural networks to produce realistic risk assessments. The systematic analysis of human exposure involves the use of measurements and models, the results of which are sometimes used in regulatory decisions or in the drafting of legislation. Because of limited scientific understanding, however, interpretation of models often involves substantial uncertainty. Extensive measurement programs can be very expensive. The high complexity and inherent heterogeneity of exposure analysis is still a major challenge. The approach to this challenge tested here is to use a new model incorporating sophisticated artificial intelligence algorithms. Exposure assessment often requires that a number of factors be evaluated, including exposure concentrations, intake rates, exposure times, and frequencies. These factors are incorporated into a system that can "learn" the relevant relationships based on a known data set. The results can then be applied to new data sets and thus be applied widely without the need for extensive measurements. In this analysis, an example is developed for human health risk through inhalation exposure to benzene from vehicular emissions in the cities of Auckland and Christchurch, New Zealand. Risk factors considered were inhaled contaminant concentration, age, body weight, and activity patterns of humans. Three major variables affecting the inhaled contaminant concentration were emissions (mainly from motor vehicles), meteorology (wind speed, temperature, and atmospheric stability), and site factors (hilly, flat, etc.). The results are preliminary and used principally to demonstrate the technique, but they are very encouraging.