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Sample records for airborne dust collected

  1. Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea.

    PubMed

    Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

    2012-04-30

    Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 μm size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 μm size fractions collected on railroad ties appeared to be smaller than 10 μm, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount of Fe mixed with Na, Mg, Al, Si, S, Ca, and C. The difference in composition of the Fe-containing particles between the two subway stations was attributed to the different ballast tracks used. PMID:22381374

  2. Chemical speciation of size-segregated floor dusts and airborne magnetic particles collected at underground subway stations in Seoul, Korea.

    PubMed

    Jung, Hae-Jin; Kim, BoWha; Malek, Md Abdul; Koo, Yong Sung; Jung, Jong Hoon; Son, Youn-Suk; Kim, Jo-Chun; Kim, HyeKyoung; Ro, Chul-Un

    2012-04-30

    Previous studies have reported the major chemical species of underground subway particles to be Fe-containing species that are generated from wear and friction processes at rail-wheel-brake and catenaries-pantographs interfaces. To examine chemical composition of Fe-containing particles in more details, floor dusts were collected at five sampling locations of an underground subway station. Size-segregated floor dusts were separated into magnetic and non-magnetic fractions using a permanent magnet. Using X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDX), iron metal, which is relatively harmless, was found to be the dominating chemical species in the floor dusts of the <25 μm size fractions with minor fractions of Mg, Al, Si, Ca, S, and C. From SEM analysis, the floor dusts of the <25 μm size fractions collected on railroad ties appeared to be smaller than 10 μm, indicating that their characteristics should somewhat reflect the characteristics of airborne particles in the tunnel and the platform. As most floor dusts are magnetic, PM levels at underground subway stations can be controlled by removing magnetic indoor particles using magnets. In addition, airborne subway particles, most of which were smaller than 10 μm, were collected using permanent magnets at two underground subway stations, namely Jegi and Yangjae stations, in Seoul, Korea. XRD and SEM/EDX analyses showed that most of the magnetic aerosol particles collected at Jegi station was iron metal, whereas those at Yangjae station contained a small amount of Fe mixed with Na, Mg, Al, Si, S, Ca, and C. The difference in composition of the Fe-containing particles between the two subway stations was attributed to the different ballast tracks used.

  3. Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust.

    PubMed

    Barone, T L; Patts, J R; Janisko, S J; Colinet, J F; Patts, L D; Beck, T W; Mischler, S E

    2016-01-01

    Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine.

  4. Longitudinal study of dust and airborne endotoxin in the home.

    PubMed

    Park, J H; Spiegelman, D L; Burge, H A; Gold, D R; Chew, G L; Milton, D K

    2000-11-01

    To characterize the seasonal variability of endotoxin levels, we measured endotoxin in dust from the bed, bedroom floor, and kitchen floor in 20 homes, and in air from the bedroom in 15 of the homes. All homes were located in the greater Boston, Massachusetts, area and were sampled each month from April 1995 to June 1996. Outdoor air was collected at two locations. We found greater within-home than between-home variance for bedroom floor, kitchen floor, and airborne endotoxin. However, the reverse was true for bed dust endotoxin. Thus, studies using single measurements of dust endotoxin are most likely to reliably distinguish between homes if bed dust is sampled. Dust endotoxin levels were not significantly associated with airborne endotoxin. Airborne endotoxin was significantly (p = 0. 04) and positively associated with absolute humidity in a mixed-effect model adjusting for a random home effect and fixed effect of sampling month and home characteristics. This finding implies that indoor humidity may be an important factor controlling endotoxin exposure. We found a significant (p < 0.05) seasonal effect in kitchen floor dust (spring > fall) and bedroom airborne endotoxin (spring > winter), but not in the other indoor samples. We found significant seasonal pattern in outdoor airborne endotoxin (summer > winter). PMID:11102291

  5. Airborne Dust in Space Vehicles and Habitats

    NASA Technical Reports Server (NTRS)

    James, John

    2006-01-01

    Airborne dust, suspended inside a space vehicle or in future celestial habitats, can present a serious threat to crew health if it is not controlled. During the Apollo missions to the moon, lunar dust brought inside the capsule caused eye irritation and breathing difficulty to the crew when they launched from the moon and re-acquired "microgravity." During Shuttle flights reactive and toxic dusts such as lithium hydroxide have created a risk to crew health, and fine particles from combustion events can be especially worrisome. Under nominal spaceflight conditions, airborne dusts and particles tend to be larger than on earth because of the absence of gravity settling. Aboard the ISS, dusts are effectively managed by HEPA filters, although floating dust in newly-arrived modules can be a nuisance. Future missions to the moon and to Mars will present additional challenges because of the possibility that external dust will enter the breathing atmosphere of the habitat and reach the crew's respiratory system. Testing with simulated lunar and Martian dust has shown that these materials are toxic when placed into the lungs of test animals. Defining and evaluating the physical and chemical properties of Martian dusts through robotic missions will challenge our ability to prepare better dust simulants and to determine the risk to crew health from exposure to such dusts.

  6. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  7. Airborne Dust Models in Valley Fever Research

    NASA Astrophysics Data System (ADS)

    Sprigg, W. A.; Galgiani, J. N.; Vujadinovic, M.; Pejanovic, G.; Vukovic, A. J.; Prasad, A. K.; Djurdjevic, V.; Nickovic, S.

    2011-12-01

    Dust storms (haboobs) struck Phoenix, Arizona, in 2011 on July 5th and again on July 18th. One potential consequence: an estimated 3,600 new cases of Valley Fever in Maricopa County from the first storm alone. The fungi, Coccidioides immitis, the cause of the respiratory infection, Valley Fever, lives in the dry desert soils of the American southwest and southward through Mexico, Central America and South America. The fungi become part of the dust storm and, a few weeks after inhalation, symptoms of Valley Fever may appear, including pneumonia-like illness, rashes, and severe fatigue. Some fatalities occur. Our airborne dust forecast system predicted the timing and extent of the storm, as it has done with other, often different, dust events. Atmosphere/land surface models can be part of public health services to reduce risk of Valley Fever and exacerbation of other respiratory and cardiovascular illness.

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

    PubMed

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

    2010-02-01

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

  9. Airborne dust particle counting techniques.

    PubMed

    Sharma, S G; Prasad, B D

    2006-03-01

    The paper briefly describes an electro-optical system for counting of dust particles, which is based on the scattering phenomena. Utilizing the scattering of light by various size particles present in the environment, various particle counting techniques have been developed in order to measure the scattered intensity of light. Light scatters in all directions but much more in the so-called near forward direction 17( composite function) off axis, at 163( composite function) from the light source in the visible range. On the basis of two techniques, the right angle and forward angle scattering, opto-mechanical systems have been developed which measure scattered intensity and particulate matter. The forward scattering Nephelometer is more sensitive and therefore is more suitable for pollution monitoring than the right angle scattering Nephelometer. Whereas the right angle scattering Nephelometer has the utility in extremely low concentration in ppb level owing to the excellent light trap efficiency in comparison to forward scattering Nephelometer. In this paper measurement techniques and measurement results associated with design and development of a real time particle analyser are also discussed.

  10. Immune Alterations in Rats Exposed to Airborne Lunar Dust

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Quiriarte, Heather; Nelman, Mayra; Lam, Chiu-wing; James, John T.; Sams, Clarence

    2014-01-01

    The lunar surface is covered by a layer of fine, reactive dust. Very little is known regarding the toxicity of lunar dust on human physiology. This study assessed the toxicity of airborne lunar dust exposure in rats on pulmonary and systemic immune parameters.

  11. Mineralogical, Chemical, and Optical Interrelationships of Airborne Mineral Dusts

    NASA Astrophysics Data System (ADS)

    Engelbrecht, J. P.; Moosmuller, H.; Pincock, S. L.; Jayanty, R. K. M.; Casuccio, G.

    2014-12-01

    The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The < 38 μm sieved fraction of each sample was re-suspended in an entrainment chamber, from which the airborne mineral dust could be monitored, sampled and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5 particulate mass fractions, an aerodynamic particle size (APS) analyzer, and a three wavelength (405, 532, 781nm) photoacoustic resonator with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sample media included Teflon® membrane and quartz fiber filters for chemical analysis (71 species), and Nuclepore® filters for individual particle analysis by Scanning Electron Microscopy (SEM). The < 38 μm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the > 38 μm, < 125 μm soil fractions were mineralogically characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will

  12. Microbial immigration across the Mediterranean via airborne dust.

    PubMed

    Rosselli, Riccardo; Fiamma, Maura; Deligios, Massimo; Pintus, Gabriella; Pellizzaro, Grazia; Canu, Annalisa; Duce, Pierpaolo; Squartini, Andrea; Muresu, Rosella; Cappuccinelli, Pietro

    2015-01-01

    Dust particles lifting and discharge from Africa to Europe is a recurring phenomenon linked to air circulation conditions. The possibility that microorganisms are conveyed across distances entails important consequences in terms of biosafety and pathogens spread. Using culture independent DNA-based analyses via next generation sequencing of the 16 S genes from the airborne metagenome, the atmospheric microbial community was characterized and the hypothesis was tested that shifts in species diversity could be recorded in relation to dust discharge. As sampling ground the island of Sardinia was chosen, being an ideal cornerstone within the Mediterranean and a crossroad of wind circulation amidst Europe and Africa. Samples were collected in two opposite coastal sites and in two different weather conditions comparing dust-conveying winds from Africa with a control situation with winds from Europe. A major conserved core microbiome was evidenced but increases in species richness and presence of specific taxa were nevertheless observed in relation to each wind regime. Taxa which can feature strains with clinical implications were also detected. The approach is reported as a recommended model monitoring procedure for early warning alerts in frameworks of biosafety against natural spread of clinical microbiota across countries as well as to prevent bacteriological warfare. PMID:26542754

  13. Microbial immigration across the Mediterranean via airborne dust

    PubMed Central

    Rosselli, Riccardo; Fiamma, Maura; Deligios, Massimo; Pintus, Gabriella; Pellizzaro, Grazia; Canu, Annalisa; Duce, Pierpaolo; Squartini, Andrea; Muresu, Rosella; Cappuccinelli, Pietro

    2015-01-01

    Dust particles lifting and discharge from Africa to Europe is a recurring phenomenon linked to air circulation conditions. The possibility that microorganisms are conveyed across distances entails important consequences in terms of biosafety and pathogens spread. Using culture independent DNA-based analyses via next generation sequencing of the 16 S genes from the airborne metagenome, the atmospheric microbial community was characterized and the hypothesis was tested that shifts in species diversity could be recorded in relation to dust discharge. As sampling ground the island of Sardinia was chosen, being an ideal cornerstone within the Mediterranean and a crossroad of wind circulation amidst Europe and Africa. Samples were collected in two opposite coastal sites and in two different weather conditions comparing dust-conveying winds from Africa with a control situation with winds from Europe. A major conserved core microbiome was evidenced but increases in species richness and presence of specific taxa were nevertheless observed in relation to each wind regime. Taxa which can feature strains with clinical implications were also detected. The approach is reported as a recommended model monitoring procedure for early warning alerts in frameworks of biosafety against natural spread of clinical microbiota across countries as well as to prevent bacteriological warfare. PMID:26542754

  14. Elemental composition of airborne dust in the Shale Shaker House during an offshore drilling operation.

    PubMed

    Hansen, A B; Larsen, E; Hansen, L V; Lyngsaae, M; Kunze, H

    1991-12-01

    During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively coupled plasma-mass spectrometry). The total amount of dust collected varied from 0.04 to 1.41 mg m-3 with barium (Ba) as the single most abundant element. The open shale shakers turned out to be the major cause of generation of dust from the solid components of the drilling mud.

  15. Elemental composition of airborne dust in the Shale Shaker House during an offshore drilling operation.

    PubMed

    Hansen, A B; Larsen, E; Hansen, L V; Lyngsaae, M; Kunze, H

    1991-12-01

    During 2 days of an offshore drilling operation in the North Sea, 16 airborne dust samples from the atmosphere of the Shale Shaker House were collected onto filters. During this operation, drilling mud composed of a water slurry of barite (BaSO4) together with minor amounts of additives, among them chrome lignosulphonate and chrome lignite, was circulated between the borehole and the Shale Shaker House. The concentration of airborne dust in the atmosphere was determined and the elemental composition of the particles analysed by both PIXE (proton-induced X-ray emission) and ICP-MS (inductively coupled plasma-mass spectrometry). The total amount of dust collected varied from 0.04 to 1.41 mg m-3 with barium (Ba) as the single most abundant element. The open shale shakers turned out to be the major cause of generation of dust from the solid components of the drilling mud. PMID:1768013

  16. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  17. Methods to assess airborne concentrations of cotton dust.

    PubMed

    Corn, M

    1987-01-01

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

  18. Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China.

    PubMed Central

    Olenchock, S A; Christiani, D C; Mull, J C; Ye, T T; Lu, P L

    1983-01-01

    Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels. PMID:6639029

  19. Airborne Imagery Collections Barrow 2013

    DOE Data Explorer

    Cherry, Jessica; Crowder, Kerri

    2015-07-20

    The data here are orthomosaics, digital surface models (DSMs), and individual frames captured during low altitude airborne flights in 2013 at the Barrow Environmental Observatory. The orthomosaics, thermal IR mosaics, and DSMs were generated from the individual frames using Structure from Motion techniques.

  20. Changes in the Airborne Bacterial Community in Outdoor Environments following Asian Dust Events

    PubMed Central

    Yamaguchi, Nobuyasu; Park, Jonguk; Kodama, Makiko; Ichijo, Tomoaki; Baba, Takashi; Nasu, Masao

    2014-01-01

    Bacterial abundance and community compositions have been examined in aeolian dust in order to clarify their possible impacts on public health and ecosystems. The influence of transcontinentally transported bacterial cells on microbial communities in the outdoor environments of downwind areas should be determined because the rapid influx of a large amount of bacterial cells can disturb indigenous microbial ecosystems. In the present study, we analyzed bacteria in air samples (approximately 100 m3 d−1) that were collected on both Asian dust days and non-Asian dust days over 2 years (between November 2010 and July 2012). Changes in bacterial abundance and community composition were investigated based on their 16S rRNA gene amount and sequence diversity. Seasonal monitoring revealed that airborne bacterial abundance was more than 10-fold higher on severe dust days, while moderate dust events did not affect airborne bacterial abundance. A comparison of bacterial community compositions revealed that bacteria in Asian dust did not immediately disturb the airborne microbial community in areas 3,000–5,000 km downwind of dust source regions, even when a large amount of bacterial cells were transported by the atmospheric event. However, microbes in aeolian dust may have a greater impact on indigenous microbial communities in downwind areas near the dust source. Continuous temporal and spatial analyses from dust source regions to downwind regions (e.g., from the Gobi desert to China, Korea, Japan, and North America) will assist in estimating the impact of atmospherically transported bacteria on indigenous microbial ecosystems in downwind areas. PMID:24553107

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

    PubMed

    Layton, David W; Beamer, Paloma I

    2009-11-01

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

  2. Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline

    USGS Publications Warehouse

    Griffin, Dale W.; Kubilay, Nilgün; Kocak, Mustafa; Gray, Mike A.; Borden, Timothy C.; Shinn, Eugene A.

    2007-01-01

    Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust measurements demonstrated that the region is routinely impacted by dust generated regionally and from North Africa and that the highest combined percent recovery of total CFU and African dust deposition occurred in the month of April (93.4% of CFU recovery and 91.1% of dust deposition occurred during African dust days versus no African dust present, for that month). A statistically significant correlation was observed (peak regional African dust months of March, April and May; rs=0.576, P=0.000) between an increase in the prevalence of microorganisms recovered from atmospheric samples on dust days (regional and African as determined by ground-based dust measurements), versus that observed on non-dust days. Given the prevalence of atmospherically suspended desert dust and microorganisms observed in this study, and that culture-based studies typically only recover a small fraction (

  3. Dust collection on serviceable satellites

    NASA Technical Reports Server (NTRS)

    Nuth, J. A., III

    1986-01-01

    One rationale for the Space Shuttle program which was dramatically realized during the repair of the Solar Maximum Mission (SMM) is the efficiency of in-orbit satellite servicing. An unexpected benefit of this repair mission was the return of parts of the Solar Max satellite which had been exposed for four years to the space environment. Studies conducted on these parts have yielded valuable data on the micrometeorite flux and composition at shuttle altitudes during this time period. The scientific results from studies of the cosmic dust component of the observed particle impacts are not yet complete but it is clear from the preliminary data available that such studies will be a valuable adjunct to the studies of cosmic dust particles collected in the atmosphere. The success of the initial studies of particles collected during repairs of the SMM spacecraft on a surface not specifically designed as a particle collector nor retrieved in a manner intended to minimize or eliminate local contamination raises the possibility that even more interesting results might be obtained if serviceable satellites were initially designed with these objectives in mind. All designs for modern satellites utilize some form of thermal blanket material in order to minimize thermal stresses inside the spacecraft. It is proposed that all future satellites be designed with standardized removeable sections of thermal blanket material which could be replaced during on-orbit servicing and returned to earth for detailed study.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  5. Examination of water spray airborne coal dust capture with three wetting agents

    PubMed Central

    Organiscak, J.A.

    2015-01-01

    Water spray applications are one of the principal means of controlling airborne respirable dust in coal mines. Since many coals are hydrophobic and not easily wetted by water, wetting agents can be added to the spray water in an effort to improve coal wetting and assist with dust capture. In order to study wetting agent effects on coal dust capture, laboratory experiments were conducted with three wetting agents used by the coal industry on -325 mesh sized Pocahontas No. 3 coal dust. Significant differences in coal dust sink times were observed among the three wetting agents at water mixture concentrations of 0.05%, 0.1% and 0.2%. The best wetting agent as identified by the coal dust sink test was only tested at the lowest 0.05% water mixture concentration and was found to have a negligible effect on spray airborne dust capture. Water spray airborne dust capture results for all three wetting agents tested at a 0.2% water mixture concentration showed that all three wetting agents exhibit similar but small improvements in dust capture efficiency as compared with water. These results indicate that the coal dust sink test may not be a good predictor for the capture of airborne dust. Additional research is needed to examine if the coal dust sink test is a better predictor of wetting agent dust suppression effects during cutting, loading, conveying and dumping of coal products by comparison to airborne dust capture from sprays. PMID:26251565

  6. Electrospray Collection of Lunar Dust

    NASA Technical Reports Server (NTRS)

    Dziekan, Michael

    2012-01-01

    A report describes ElectroSpray Ionization based Electrostatic Precipitation (ESIEP) for collecting lunar dust particles. While some HEPA filtration processes may remove a higher fraction (>99.9 percent) of the particles, the high efficiency may not be appropriate from an overall system standpoint, especially in light of the relatively large power requirement that such systems demand. The new electrospray particle capture technology is described as a variant of electrostatic precipitation that eliminates the current drawbacks of electrostatic precipitation. The new approach replaces corona prone field with a mist of highly charged micro-droplets generated by electrospray ionization (ESI) as the mechanism by which incoming particles are attracted and captured. In electrospray, a miniscule flow rate (microliters/minute) of liquid (typically water and a small amount of salt to enhance conductivity) is fed from the tip of a needle held at a high voltage potential relative to an opposite counter electrode. At sufficient field strength, a sharp liquid meniscus forms , which emits a jet of highly charged droplets that drift through the surrounding gas and are collected on the walls of a conductive tube. Particles in the gas have a high probability of contact with the droplets either by adhering to the droplets or otherwise acquiring a high level of charge, causing them to be captured on the collecting electrode as well. The spray acts as a filtration material that is continuously introduced and removed from the gas flow, and thus can never become clogged.

  7. Dielectrophoretic separation of airborne microbes and dust particles using a microfluidic channel for real-time bioaerosol monitoring.

    PubMed

    Moon, Hui-Sung; Nam, Yun-Woo; Park, Jae Chan; Jung, Hyo-Il

    2009-08-01

    Airborne microbes such as fungi, bacteria, and viruses are a threat to public health. Robust and real-time detection systems are necessary to prevent and control such dangerous biological particles in public places and dwellings. For direct and real-time detection of airborne microbes, samples must be collected and typically resuspended in liquid prior to detection; however, environmental particles such as dust are also trapped in such samples. Therefore, the isolation of target bacteria or a selective collection of microbes from unwanted nonbiological particles prior to detection is of great importance. Dielectrophoresis (DEP), the translational motion of charge neutral matter in nonuniform electric fields, is an emerging technique that can rapidly separate biological particles in microfluidics because low voltages produce significant and contactless forces on particles without any modification or labeling. In this paper, we propose a new method for the separation of airborne microbes using DEP with a simple and novel curved electrode design for separating bacteria in a solution containing beads or dust that are taken from an airborne environmental sample. Using this method, we successfully isolated 90% of the airborne bacterium Micrococcus luteus from a mixture of bacteria and dust using a microfluidic device, consisting of novel curved electrodes that attract bacteria and repel or leave dust particles. As there has been little research on analyzing environmental samples using microfluidics and DEP, this work describes a novel strategy for a rapid and direct bioaerosol monitoring system.

  8. The application of performance standards to personal airborne dust samplers.

    PubMed

    Kenny, L C; Lidén, G

    1989-01-01

    This paper summarizes current proposals for the specification and testing of personal sampler performance, and discusses their implications for the precision of dust concentration estimates. A method of specifying the performance of a sampling instrument in terms of the range of masses it would collect from various dust clouds is proposed. Some of the practical difficulties which are likely to arise in the process of testing real samplers with respect to performance standards are discussed.

  9. Considerations when collecting coal dust

    SciTech Connect

    Olechiw, W.J.

    1995-12-31

    There are several applications in the handling of coal in which capturing coal dust is important. They are in pulverizing operations at belt conveyor transfer points and pneumatic conveying receivers. In each case the processing and handling of coal generates considerable dust which is suspended in the air. Health and safety, environmental considerations and good housekeeping practices dictate that the suspended coal dust be captured, contained and transferred for re-use or disposal. It is no longer acceptable practice to expose operating personnel to breathing dust (OSSA regulations). In addition particulate emissions are being more closely regulated both in total mass and particle size (PM-10 legislation). In general dusty environments reduce the efficiency of operating equipment by fouling bearings and rollers, increasing friction, clogging air filters and increasing wear and tear on equipment and energy costs. Of paramount concern is the fact that spontaneous combustion can occur where coal dust accumulates on horizontal surfaces.

  10. Exposure to airborne microorganisms, dust and endotoxin during processing of peppermint and chamomile herbs on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during processing of peppermint (Mentha piperita) and chamomile (Matricaria recutita) by herb farmers, and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 13 farms owned by herb cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the farm air during processing of peppermint herb were large, within a range from 895.1-6,015.8 x 10(3) cfu/m(3) (median 1,055.3 x 10(3) cfu/m(3)). During processing of chamomile herb they were much lower and varied within a range from 0.88-295.6 x 10(3) cfu/m(3) (median 27.3 x 10(3) cfu/m(3)). Gram-negative bacteria distinctly prevailed during processing of peppermint leaves, forming 46.4-88.5 % of the total airborne microflora. During processing of chamomile herb, Gram-negative bacteria were dominant at 3 out of 6 sampling sites forming 54.7-75.3 % of total microflora, whereas at the remaining 3 sites the most common were fungi forming 46.2-99.9 % of the total count. The species Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans ), having strong allergenic and endotoxic properties, distinctly prevailed among Gram-negative isolates. Among fungi, the most common species was Alternaria alternata. The concentrations of airborne dust and endotoxin determined on the examined herb farms were large. The concentrations of airborne dust during peppermint and chamomile processing ranged from 86.7-958.9 mg/m(3), and from 1.1-499.2 mg/m(3), respectively (medians 552.3 mg/m(3) and 12.3 mg/m(3)). The concentrations of airborne endotoxin determined during peppermint and chamomile processing were within a wide range 1.53-208.33 microg/m(3) and 0.005-2604.19 microg/m(3) respectively (medians 57.3 microg/m(3) and 0.96 microg/m(3)). In conclusion, farmers

  11. Characteristics of airborne coal mine dust and its implication to coal workers' pneumoconiosis

    SciTech Connect

    Kim, H.

    1989-01-01

    Size selective airborne dust samples were collected using 4-stage cassette impactors at nine different locations in continuous mining sections in each of five coal seams located in the Appalachian bituminous coal field. These coal seams were the Upper Freeport, Pittsburgh, Kittanning, Coalburg, and Pocahontas. Mineralogical analyses were performed by an x-ray powder diffraction photographic technique. The distributions of total and respirable dust concentrations were fit best by a log-normal distribution. The effects of the coal seam and the sampling location on dust levels were significant. The results of the particle size distribution analyses suggest that coal mine dust has a multi-modal distribution. The effects of the coal seam and the sampling locations were significant. The distributions obtained were often affected by such mine-related variables as ventilation rate, relative humidity, and the section dimensions. Nine minerals commonly found in the coal mine dust samples collected from the coal seams studied were illite, calcite, kaolinite, quartz, dolomite, siderite, gypsum, anhydrite, and pyrite in descending order of magnitude. Relative abundance of all mineral species except siderite and gypsum was coal seam specific and suggests that existence of coal seam variability of mineral content. Although mineral content was affected by sampling locations and the sections within a mine, the magnitude was small when compared with that of cal seams. Mineral content also appears to be affected by particle size, although no particular pattern was observed.

  12. Health effects of particulate air pollution and airborne desert dust

    NASA Astrophysics Data System (ADS)

    Lelieveld, J.; Pozzer, A.; Giannadaki, D.; Fnais, M.

    2013-12-01

    Air pollution by fine particulate matter (PM2.5) has increased strongly with industrialization and urbanization. In the past decades this increase has taken place at a particularly high pace in South and East Asia. We estimate the premature mortality and the years of human life lost (YLL) caused by anthropogenic PM2.5 and airborne desert dust (DU2.5) on regional and national scales (Giannadaki et al., 2013; Lelieveld et al., 2013). This is based on high-resolution global model calculations that resolve urban and industrial regions in relatively great detail. We apply an epidemiological health impact function and find that especially in large countries with extensive suburban and rural populations, air pollution-induced mortality rates have been underestimated given that previous studies largely focused on the urban environment. We calculate a global premature mortality by anthropogenic aerosols of 2.2 million/year (YLL ≈ 16 million/year) due to lung cancer and cardiopulmonary disease. High mortality rates by PM2.5 are found in China, India, Bangladesh, Pakistan and Indonesia. Desert dust DU2.5 aerosols add about 0.4 million/year (YLL ≈ 3.6 million/year). Particularly significant mortality rates by DU2.5 occur in Pakistan, China and India. The estimated global mean per capita mortality caused by airborne particulates is about 0.1%/year (about two thirds of that caused by tobacco smoking). We show that the highest premature mortality rates are found in the Southeast Asia and Western Pacific regions (about 25% and 46% of the global rate, respectively) where more than a dozen of the most highly polluted megacities are located. References: Giannadaki, D., A. Pozzer, and J. Lelieveld, Modeled global effects of airborne desert dust on air quality and premature mortality, Atmos. Chem. Phys. Discuss. (submitted), 2013. Lelieveld, J., C. Barlas, D. Giannadaki, and A. Pozzer, Model calculated global, regional and megacity premature mortality due to air pollution by ozone

  13. Effect of an electrostatic space charge system on airborne dust and subsequent potential transmission of microorganisms to broiler breeder pullets by airborne dust.

    PubMed

    Richardson, L J; Mitchell, B W; Wilson, J L; Hofacre, C L

    2003-01-01

    High levels of dust and microorganisms are known to be associated with animal confinement rearing facilities. Many of the microorganisms are carried by dust particles, thus providing an excellent vector for horizontal disease transmission between birds. Two environmentally controlled rooms containing female broiler breeder pullets (n = 300) were used to evaluate the effectiveness of an electrostatic space charge system (ESCS) in reducing airborne dust and gram-negative bacteria levels over an 8-wk period (starting when the birds were 10 wk old). The ESCS was used to evaluate the effectiveness of reducing airborne microorganism levels by charging airborne dust particles and causing the particles to be attracted to grounded surfaces (i.e., walls, floor, equipment). The use of the ESCS resulted in a 64% mean reduction in gram-negative bacteria. Airborne dust levels were reduced an average of 37% over a 1-wk period in the experimental room compared with the control room on the basis of samples taken every 10 min. The reductions of airborne dust and bacteria in this study are comparable with earlier results obtained with the ESCS in commercial hatching cabinets and experimental caged layer rooms, suggesting the system could also be applied to other types of enclosed animal housing. PMID:12713167

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  15. [Occurrence of molds in airborne dusts in poultry farms].

    PubMed

    Gemeinhardt, H; Wallenstein, G

    1985-01-01

    To reach conclusions in terms of industrial hygiene, mycological samples were taken in modern poultry farms between 1979 and 1981. Sedimentation plates, the Krotow slit collector and the SPG-10 airborne dust sampler were used to determine the mould content of the air. The lowest germ counts were made in cage systems, while somewhat higher numbers were recorded among adult bids kept in the floor systems. Unexpectedly high numbers of mould germs were found in the air of large poultry houses where chickens were reared on relatively fresh litter. The fungus genera Penicillium and Cladosporium and, in one case, the species Scopulariopsis brevicaulis were predominant on old litter in both the floor and the cage system, whereas moulds of the Aspergillus group (Aspergillus candidus and A. versicolor) were additionally existent on fresh straw layers.

  16. Statistical analysis of the size and elemental composition of airborne coal-mine dust. Open File Report (Interim) 1984-86

    SciTech Connect

    Mutmansky, J.M.; Lee, C.

    1987-03-01

    The report was part of an ongoing effort at The Pennsylvania State University to investigate the characteristics of airborne mine dusts and its relationship to coal worker's pneumoconiosis (CWP). The specific purpose of the project was to analyze the size and elemental composition of airborne coal mine dusts and the ramifications of these characteristics. A dust sampling strategy using multi-stage cascade impactors was established for characterization purposes. Analysis of the size distributions of the collected samples was performed based upon the aerodynamic diameter of the dust. Patterns of lognormality and bimodality were found in the data. Elemental analysis was performed by the PIXE method for both major and trace elements. Size dependency and locational variation of the elemental composition of the airborne dust were significant in some cases. Relationships to the mining section activities were also investigated.

  17. Statistical analysis of the size and elemental composition of airborne coal mine dust

    SciTech Connect

    Lee, C.

    1986-01-01

    The specific purpose of this thesis is to analyze two of the basic characteristics of airborne coal mine dust, size and elemental composition, and to study their ramifications on dust control measures and medical studies of coal workers' pneumoconiosis. A dust-sampling strategy using multi-stage cascade impactors is established for characterization purposes. Analysis of the size data based upon the aerodynamic diameter is performed to examine the two assumptions implicitly made in the current practice for coal mine dust size presentation; lognormality and unimodality in the mass size distribution. The bimodal lognormal model is able to identify the major modal patterns observed in the empirical models. Association of the elemental composition of coal with the rank is tested to be significant. Size dependency and locational variation of elemental composition of airborne coal mine dust are significant. The size dependency is more significant in the immediate return of the continuous miner operation and the elements showing significant locational variability are found to be enriched near the roof bolter operation. The coal seam is the main source of major elements in airborne coal mine dust, while no consistent relationship exists for the trace elements. The significance of the dust in the intake air as a potential source for the elements in airborne coal mine dust is shown. Dust reentrained along the shuttle car route is also found to be a significant dust source. Dust particles in the respirable size range are likely to transport through the working area.

  18. Effects of studded tires on roadside airborne dust pollution in Niigata, Japan

    NASA Astrophysics Data System (ADS)

    Fukuzaki, Norio; Yanaka, Takaaki; Urushiyama, Yoshio

    Two series of dust samples, collected by Andersen impactors (denoted by AN) and low-volume air samplers (denoted by LV), were investigated with respect to roadside airborne dusts collected in two different periods in 1983. These were the periods (i) with studded tires (February and March) and (ii) without studded tires (October). Multi-element determinations of these samples were made by neutron activation analysis and atomic absorption spectrometry. The total concentration of AN in roadside air for period (i) was about three times higher than for the period without studded tires. The lithophilic elements such as Na, Al, K, Ca, Ti, Fe and Th, and component-metal elements of stud tip, W and Ta, produced a significant increase in atmospheric concentration in winter. The contribution of pavement material, one of the most interesting components of airborne particles in this study, was related to total AN and LV by the chemical element balance method. It made up only 16 percent (9.1 μgm -3) of AN in October, compared with 46 percent (70.2 μgm -3) in February. It was also observed that the atmospheric concentrations of pavement debris to total LV decreased with the distance from the road to each sampling site.

  19. MicroMED: a dust particle counter for the characterization of airborne dust close to the surface of Mars

    NASA Astrophysics Data System (ADS)

    Cozzolino, Fabio; Esposito, Francesca; Molfese, Cesare; Cortecchia, Fausto; Saggin, Bortolino; D'amato, Francesco

    2015-04-01

    Monitoring of airborne dust is very important in planetary climatology. Indeed, dust absorbs and scatter solar and thermal radiation, severely affecting atmospheric thermal structure, balance and dynamics (in terms of circulations). Wind-driven blowing of sand and dust is also responsible for shaping planetary surfaces through the formation of sand dunes and ripples, the erosion of rocks, and the creation and transport of soil particles. Dust is permanently present in the atmosphere of Mars and its amount varies with seasons. During regional or global dust storms, more than 80% of the incoming sunlight is absorbed by dust causing an intense atmospheric heating. Airborne dust is therefore a crucial climate component on Mars which impacts atmospheric circulations at all scales. Main dust parameters influencing the atmosphere heating are size distribution, abundance, albedo, single scattering phase function, imaginary part of the index of refraction. Moreover, major improvements of Mars climate models require, in addition to the standard meteorological parameters, quantitative information about dust lifting, transport and removal mechanisms. In this context, two major quantities need to be measured for the dust source to be understood: surface flux and granulometry. While many observations have constrained the size distribution of the dust haze seen from the orbit, it is still not known what the primary airborne dust (e.g. the recently lifted dust) is made of, size-wise. MicroMED has been designed to fill this gap. It will measure the abundance and size distribution of dust, not in the atmospheric column, but close to the surface, where dust is lifted, so to be able to monitor dust injection into the atmosphere. This has never been performed in Mars and other planets exploration. MicroMED is an Optical Particle Counter, analyzing light scattered from single dust particles to measure their size and abundance. A proper fluid-dynamic system, including a pump and a

  20. Exposure to airborne microorganisms, dust and endotoxin during processing of valerian roots on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during various stages of valerian (Valeriana officinalis) roots processing by herb farmers and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 15 farms owned by valerian cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the air showed a marked variability and were within a range of 0.95-7,966.6 x 10(3) cfu/m (3). Though median was relatively low (10.75 x 10(3) cfu/m (3)), on 4 farms the concentrations exceeded the level of 10(5) cfu/m (3) and on 1 farm the level of 10(6) cfu/m (3). During the processing of valerian roots, distinct changes could be observed in the composition of airborne microflora. In the first stages of processing, the freshly dug and washed roots until shaking in the drying room, the most numerous were Gram-negative bacteria of the family Pseudomonadaceae (mostly Stenotrophomonas maltophilia, Pseudomonas chlororaphis and Pseudomonas fluorescens). After drying, the dominant organisms were thermo-resistant endospore-forming bacilli (Bacillus spp.) and fungi, among which prevailed Aspergillus fumigatus. Altogether, 29 species or genera of bacteria and 19 species or genera of fungi were identified in the farm air during valerian processing, of these, 10 and 12 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of airborne dust and endotoxin on the examined farms were very large and ranged from 10.0-776.7 mg/m (3), and from 0.15-24,448.2 microg/m (3), respectively (medians 198.3 mg/m (3) and 40.48 microg/m (3)). In conclusion, farmers cultivating valerian could be exposed during processing of valerian roots to large concentrations of airborne microorganisms, dust and endotoxin posing a risk of work

  1. On the visibility of airborne volcanic ash and mineral dust

    NASA Astrophysics Data System (ADS)

    Weinzierl, B.; Sauer, D. N.; Minikin, A.; Reitebuch, O.; Dahlkötter, F.; Mayer, B. C.; Emde, C.; Tegen, I.; Gasteiger, J.; Petzold, A.; Veira, A.; Kueppers, U.; Schumann, U.

    2012-12-01

    After the eruption of the Eyjafjalla volcano (Iceland) in April 2010 which caused the most extensive restrictions of the airspace over Europe since the end of World War II, the aviation safety concept of avoiding "visible ash", i.e. volcanic ash that can be seen by the human eye, was recommended. However so far, no clear definition of "visible ash" and no relation between the visibility of an aerosol layer and related aerosol mass concentrations are available. The goal of our study is to assess whether it is possible from the pilot's perspective in flight to detect the presence of volcanic ash and to distinguish between volcanic ash and other aerosol layers just by sight. In our presentation, we focus the comparison with other aerosols on aerosol types impacting aviation: Besides volcanic ash, dust storms are known to be avoided by aircraft. We use in-situ and lidar data as well photographs taken onboard the DLR research aircraft Falcon during the Saharan Mineral Dust Experiments (SAMUM) in 2006 and 2008 and during the Eyjafjalla volcanic eruption in April/May 2010. We complement this analysis with numerical modelling, using idealized radiative transfer simulations with the 3D Monte Carlo radiative transfer code MYSTIC for a variety of selected viewing geometries. Both aerosol types, Saharan mineral dust and volcanic ash, show an enhanced coarse mode (> 1 μm) aerosol concentration, but volcanic ash aerosol additionally contains a significant number of Aitken mode particles (< 150 nm). Volcanic ash is slightly more absorbing than mineral dust, and the spectral behaviour of the refractive index is slightly different. According to our simulations, these differences are not detectable just by human eye. Furthermore, our data show, that it is difficult to define a lower threshold for the visibility of an aerosol layer because the visual detectability depends on many parameters, including the thickness of the aerosol layer, the brightness and color contrast between the

  2. Influence of coal type on water spray suppression of airborne respirable dust

    SciTech Connect

    Organiscak, J.A. ); Leon, M.H. )

    1994-08-01

    A laboratory study was conducted to investigate the water spray capture efficiency of airborne respirable dust generated from nine different bituminous coal seams. Experiments involved grinding a uniform coal sample mass, injecting the dust into a closed steady-state chamber, and measuring the aerosol's decay response when exposed to a hollow cone water spray. The amount of airborne dust generated from these differential coal types varied, but had similar particle size distributions. The spray knockdown efficiency was comparable among coal types, and the size distribution of the dust was uniformly reduced by the water spray. Since water spray capture efficiency remained essentially uniform, the dust concentration at the end of the spray period was a function of the amount of dust generated. Therefore, a particular water spray system used in different coal seams under identical operating conditions (seam height, airflow, water pressure and flow, mining practices, etc.) can be expected to remove airborne dust in a uniform manner. However, dust concentrations will likely vary around identical water spray control systems used in different underground mines because of the diversity in operating conditions and the amount of dust generated from different coal scams. 11 refs., 8 figs., 3 tabs.

  3. An evaluation of effect of airborne dust from a cotton mill on the guinea-pig ileum with reference to byssinosis.

    PubMed

    Cinkotai, F F; Franklin, D W

    1975-08-01

    The effect of airborne dust on the guinea-pig ileum was studied. Tyrode extracts of airborne dust collected freshly in the cardroom of a cotton mill, and extracts of air pollutant samples drawn on the roof of the mill and of the local town hall were all found to induce the guinea-pig ileum to contract when applied in a tissue-bath. However, the force of contraction with air pollutants was rather greater than that with the cardroom dust. Considering the variables involved, the ileum response to the cardroom dust may have been due to ordinary air pollutants which constitute a significant part of the dust. It is concluded that this pharmacological phenomenon is probably not relevant in the context of byssinosis.

  4. 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.

  5. Long-Term Variability of Airborne Asian Dust Observed from TOMS

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Hsu, N. C.; Seftor, C. J.; Holben, B. N.; Holben, B. N.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Recent studies suggest that airborne Asian dust may not only play an important role in the regional radiation budget, but also influence the air quality over North America through long-range transport. In this paper, we use satellite data to investigate the long-term variability of airborne Asian dust as well as the daily variation of the dust aerosol distribution. By combining the Total Ozone Mapping Spectrometer (TOMS) aerosol index with National Centers for Environmental Prediction (NCEP) wind data, our analysis shows a strong correlation between the generation of dust storms in the region and the passage of springtime weather fronts. This is consistent with earlier studies performed by other researchers. According to both the Nimbus-7 and Earth-Probe TOMS data the Takla Makan desert, the Gobi desert, and the and region of Inner Mongolia are major sources of the eastward-flowing airborne Asian dust. Heavily populated areas in eastern China (e.g., Beijing) are often on the primary path of the dust storms originating in these desert regions. The increasing desertification north of the Beijing region has served to exacerbate problems stemming from these storms. The time series derived from 20 years of TOMS aerosol index data shows the first significant satellite evidence of the atmospheric effect of increasing desertification, indicating that the amount of dust blown eastward has increased strongly during the past few years including the year 2000.

  6. A brief report of gram-negative bacterial endotoxin levels in airborne and settled dusts in animal confinement buildings

    SciTech Connect

    Thedell, T.D.; Mull, J.C.; Olenchock, S.A.

    1980-01-01

    Gram-negative bacterial endotoxins, implicated in adverse worker health responses, were found in settled and airborne dust samples obtained from poultry and swine confinement units. Results of the Limulus amebocyte lysate gel test found endotoxin levels in dust samples ranged from 4.5 to 47.7 micrograms of FDA Klebsiella endotoxin equivalents/gm. Differences in endotoxin levels between dust samples may have been due to variables in time, geographic locations, confined animals, confinement buildings and equipment, and methods of sample collection. Animal confinement workers are potentially exposed to large amounts of gram-negative bacterial endotoxins; however, the respiratory health effects of such exposures to animal confinement workers have yet to be determined.

  7. Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust, volume 73

    NASA Technical Reports Server (NTRS)

    Haas, Michael R. (Editor); Davidson, Jacqueline A. (Editor); Erickson, Edwin F. (Editor)

    1995-01-01

    This symposium was organized to review the science related to NASA's Airborne Astronomy Program on the occasion of the twentieth anniversary of the Kuiper Airborne Observatory (KAO). The theme selected, 'The Galactic Ecosystem: From Gas to Stars to Dust,' was considered to capture the underlying commonality of much of the research discussed. The 8 sessions were as follows: The Interstellar Medium; The Life Cycle of the ISM in Other Galaxies; Star and Planetary System Formation; Our Planetary System: The Solar System; The Enrichment of the Interstellar Medium; The Galactic Center: A Unique Region of the Galactic Ecosystem; Instrumentation for Airborne Astronomy; KAO History and Education; and Missions and the Future of Infrared Astronomy.

  8. Collective excitations and dust particles in space

    NASA Technical Reports Server (NTRS)

    Gilra, D. P.

    1972-01-01

    It is shown that observed bands at 2200 A and in the 10 micron region are most probably due to collective excitations of dust particles. The following specific conclusions are drawn: (1) the 2200 A interstellar band is very likely due to graphite particles; (2) these graphite particles should be very small, approximately spherical, and should have no coating whatsoever; (3) the identification of circumstellar and interstellar silicates from the observations in the 10 micron region does not seem to be correct; (4) very valuable information about the shape of the circumstellar and interstellar dust particles can be obtained directly from observations; and (5) narrow band polarization measurements in the spectral regions of these bands will be very helpful in determining the shape of the particles.

  9. Using proximate analysis to characterize airborne dust generation from bituminous coals

    SciTech Connect

    Page, S.J.; Organiscak, J.A.

    2005-11-01

    Prolonged exposure to airborne respirable coal dust is responsible for coal workers pneumoconiosis (CWP), commonly called black lung. Health research studies have identified that the prevalence and severity of CWP are directly related to both the amount of dust exposure and the coal rank. The amount of airborne respirable dust (ARD) smaller than 10 micrometers generated from breakage of different coals varies widely. To investigate the cause, researchers for the National Institute for Occupational Safety and Health (NIOSH) have conducted experiments to identify the causes of airborne respirable dust liberation. Laboratory crushing experiments were conducted on a range of low to high volatile bituminous coals from eight mines. The results indicate that the proximate analysis of a coal sample can provide a very good indicator of the potential for a dust problem. For application to the coal mining, processing, and utilization industries, data from 977 US coal seams compiled by the Department of Energy (DoE) has been used to calculate this dust generation potential from an equation based on the NIOSH measured data. A simple procedure for this calculation is provided. 1 fig.

  10. Pristine Stratospheric Collections of Cosmic Dust

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Clemett, S. J.

    2012-01-01

    Since 1981, NASA has routinely collected interplanetary dust particles (IDPs) in the stratosphere by inertial impact onto silicone oil-coated flat plate collectors deployed on the wings of high-altitude aircraft [1]. The highly viscous oil traps and localizes the particles, which can fragment during collection. Particles are removed from the collectors with a micromanipulator and washed of the oil using organic solvents, typically hexane or xylene. While silicone oil is an efficient collection medium, its use is problematic. All IDPs are initially coated with this material (polydimethylsiloxane, n(CH3)2SiO) and traces of oil may remain after cleaning. The solvent rinse itself is also a concern as it likely removes indigenous organics from the particles. To avoid these issues, we used a polyurethane foam substrate for the oil-free stratospheric collection of IDPs.

  11. Airborne Dust, "The Good Guy or the Bad Guy": How Much do We Know?

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2010-01-01

    Processes in generating, transporting, and dissipating the airborne dust particles are global phenomena -African dust regularly reaching the Alps; Asian dust seasonally crossing the Pacific into North America, and ultimately the Atlantic into Europe. One of the vital biogeochemical roles dust storms play in Earth's ecosystem is routinely mobilizing mineral dust, as a source of iron, from deserts into oceans for fertilizing the growth of phytoplankton -the basis of the oceanic food chain. Similarly, these dust-laden airs also supply crucial nutrients for the soil of tropical rain forests, the so-called womb of life that hosts 50-90% of the species on Earth. With massive amounts of dust lifted from desert regions and injected into the atmosphere, however, these dust storms often affect daily activities in dramatic ways: pushing grit through windows and doors, forcing people to stay indoors, causing breathing problems, reducing visibility and delaying flights, and by and large creating chaos. Thus, both increasing and decreasing concentrations of doses result in harmful biological effects; so do the airborne dust particles to our Living Earth. Since 1997 NASA has been successfully launching a series of satellites - the Earth Observing System - to intensively study, and gain a better understanding of, the Earth as an integrated system. Through participation in many satellite remote-sensing/retrieval and validation projects over the years, we have gradually developed and refined the SMART (Surface-sensing Measurements for Atmospheric Radiative Transfer) and COMMIT (Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile observatories, a suite of surface remote sensing and in-situ instruments that proved to be vital in providing high temporal measurements, which complement the satellite observations. In this talk, we will present SMART-COMMIT which has played key roles, serving as network or supersite, in major international research projects such

  12. Pb, Sr and Nd isotopic composition and trace element characteristics of coarse airborne particles collected with passive samplers

    NASA Astrophysics Data System (ADS)

    Hoàng-Hòa, Thi Bich; Stille, Peter; Dietze, Volker; Guéguen, Florence; Perrone, Thierry; Gieré, Reto

    2015-09-01

    Passive samplers for collection of coarse airborne particulate matter have been installed in and around the coal-mining town of Cam Pha, Quang Ninh Province (Vietnam). Analysis of Pb, Sr, and Nd isotope ratios and of major and trace element distribution patterns in atmospheric particulates collected at three stations allowed for the identification of four important dust components: (1) coal dust from an open-pit mine and fly ash particles from a coal-fired power station, (2) diesel soot, (3) traffic dust from metal, tire and pavement abrasion, and (4) limestone-derived dust. Outside of the coal-mining area, traffic-derived dust defines the atmospheric baseline composition of the studied environment.

  13. The role of airborne mineral dusts in human disease

    NASA Astrophysics Data System (ADS)

    Morman, Suzette A.; Plumlee, Geoffrey S.

    2013-06-01

    Exposure to fine particulate matter (PM) is generally acknowledged to increase risk for human morbidity and mortality. However, particulate matter (PM) research has generally examined anthropogenic (industry and combustion by-products) sources with few studies considering contributions from geogenic PM (produced from the Earth by natural processes, e.g., volcanic ash, windborne ash from wildfires, and mineral dusts) or geoanthropogenic PM (produced from natural sources by processes that are modified or enhanced by human activities, e.g., dusts from lakebeds dried by human removal of water, dusts produced from areas that have undergone desertification as a result of human practices). Globally, public health concerns are mounting, related to potential increases in dust emission from climate related changes such as desertification and the associated long range as well as local health effects. Recent epidemiological studies have identified associations between far-traveled dusts from primary sources and increased morbidity and mortality in Europe and Asia. This paper provides an outline of public health research and history as it relates to naturally occurring inorganic mineral dusts. We summarize results of current public health research and describe some of the many challenges related to understanding health effects from exposures to dust aerosols.

  14. Speciation of airborne dust from a nickel refinery roasting operation.

    PubMed

    Andersen, I; Berge, S R; Resmann, F

    1998-04-01

    Earlier work-related lung and nasal cancer studies included estimates of exposures to different nickel species in the refinery. Based on the metallurgy, only insoluble nickel was believed to be present around the roasters but mixed exposure was assumed in most areas, including the tankhouse. Occasional leaching tests of samples from the roaster area have indicated the presence of soluble nickel. This study reports on five parallel sets of dust samples collected from different floors with standard equipment and treated as follows. Two sets were leached with an ammonium citrate buffer at pH 4.4. Undissolved material was treated with HClO4/HNO3, evaporated to dryness and dissolved in HCl, Ni, Cu, Co, Fe, Se, and As were determined in both fractions. Water soluble Ni was found in all samples, ranging from 5-35%. Sulfate in the solutions correlated nearly stoichiometrically to the total metal content. The three remaining sets were investigated by, respectively, differential leaching, X-ray diffraction and scanning electron microscopy. The percentage of soluble nickel found by differential leaching corresponded well with those obtained by the simplified procedure. X-Ray diffraction analysis showed the presence of NiSO4.6H2O as well as oxides of Ni and Cu. This study indicates mixed exposures also in the roaster area. It also clearly indicates that basing exposure on the metallurgy alone can lead to serious misjudgements. The impact of this new information on the interpretation of cancer incidence at this refinery must await the analysis in an ongoing case-reference study. PMID:9684402

  15. Airborne bacteria transported with Sahara dust particles from Northern Africa to the European Alps

    NASA Astrophysics Data System (ADS)

    Lazzaro, A.; Meola, M.

    2015-12-01

    The Sahara Desert is the most important source of aerosols transported across the Mediterranean towards Europe. Airborne microorganisms associated with aerosols may be transported over long distances and act as colonizers of distant habitats. However, little is known on the composition and viability of such microorganisms, due to difficulties related to their detection, collection and isolation. Here we describe an in-depth assessment of the bacterial communities associated with Sahara dust (SD) particles deposited on snow. Two distinct SD events reaching the European Alps in February and May 2014 were preserved as distinct ochre-coloured layers within the snowpack. In June 2014, we collected samples from a snow profile at 3621 m a.s.l. close to the Jungfraujoch (Swiss Alps). SD particles were analyzed by Scanning Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy (SEM-EDX). Backward trajectories were calculated using the NOAA HYSPLIT model. Bacterial communities were charac-terized by MiSeq Illumina sequencing of the 16S rRNA gene. Microbial physiological profiles were assessed by incubation of samples on BIOLOG plates. The SD-layers were generally enriched in illite and kaolinite particles as compared to the adjacent snow layers. The source of SD could be traced back to Algeria. We observed distinct bacterial community structures in the SD-layers as compared to the clean snow layers. While sporulating bacteria were not enriched in the SD-layers, low abundant (<1%) phyla such as Gemmatimonadetes and Deinococcus-Thermus appeared to be specific bioindicators for SD. Both phyla are adapted to arid oligotrophic environments and UV radiation and thus are well suited to survive the harsh conditions of long-distance airborne transport. Our results show that bacteria are viable and metabolically active after the trek to the European Alps.

  16. Geochemical and microbiological fingerprinting of airborne dust that fell in Canberra, Australia, in October 2002

    NASA Astrophysics Data System (ADS)

    de Deckker, Patrick; Abed, Raeid M. M.; de Beer, Dirk; Hinrichs, Kai-Uwe; O'Loingsigh, Tadhg; Schefuß, Enno; Stuut, Jan-Berend W.; Tapper, Nigel J.; van der Kaars, Sander

    2008-12-01

    During the night of 22-23 October 2002, a large amount of airborne dust fell with rain over Canberra, located some 200 km from Australia's east coast, and at an average altitude of 650 m. It is estimated that during that night about 6 g m-2 of aeolian dust fell. We have conducted a vast number of analyses to "fingerprint" some of the dust and used the following techniques: grain size analysis; scanning electron microscope imagery; major, trace, and rare earth elemental, plus Sr and Nd isotopic analyses; organic compound analyses with respective compound-specific isotope analyses; pollen extraction to identify the vegetation sources; and molecular cloning of 16S rRNA genes in order to identify dust bacterial composition. DNA analyses show that most obtained 16S rRNA sequences belong mainly to three groups: Proteobacteria (25%), Bacteriodetes (23%), and gram-positive bacteria (23%). In addition, we investigated the meteorological conditions that led to the dust mobilization and transport using model and satellite data. Grain sizes of the mineral dust show a bimodal distribution typical of proximal dust, rather than what is found over oceans, and the bimodal aspect of size distribution confirms wet deposition by rain droplets. The inorganic geochemistry points to a source along/near the Darling River in NW New South Wales, a region that is characteristically semiarid, and both the organic chemistry and palynoflora of the dust confirm the location of this source area. Meteorological reconstructions of the event again clearly identify the area near Bourke-Cobar as being the source of the dust. This study paves the way for determining the export of Australian airborne dust both in the oceans and other continents.

  17. The effect of airborne dust on astronomical polarization measurements

    NASA Astrophysics Data System (ADS)

    Bailey, Jeremy; Ulanowski, Z.; Lucas, P. W.; Hough, J. H.; Hirst, E.; Tamura, M.

    2008-05-01

    In the past, it has generally been assumed that polarization observations made with ground-based telescopes are unaffected by the passage of light through the Earth's atmosphere. Here, we report observations with a new high-sensitivity astronomical polarimeter (PlanetPol) made during a Saharan dust event over the La Palma observatory in 2005 May that show excess linear polarization in the horizontal direction due to the passage of the starlight through the dust. The polarization reached a maximum value of 4.8 × 10-5 at 56° zenith distance and varied over five nights in proportion to the change in dust optical depth. Polarization of transmitted light (dichroism) does not occur for spherical or randomly oriented non-spherical particles. Thus, these results imply that some fraction of the dust grain population aligns with a preferred orientation. We use T-matrix models to demonstrate that the observed polarization direction implies a vertical orientation for the long axis of the particles. We suggest a possible mechanism for vertical orientation resulting from the electric field in the atmosphere. These results will need to be taken into account in the design and use of future instruments for high-sensitivity astronomical polarimetry. The results also indicate possible new approaches to studying aerosol particles and their effects on the Earth's atmosphere.

  18. Airborne fungal and bacterial components in PM1 dust from biofuel plants.

    PubMed

    Madsen, Anne Mette; Schlünssen, Vivi; Olsen, Tina; Sigsgaard, Torben; Avci, Hediye

    2009-10-01

    Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size (<1.5 microm). High exposures to fungi and bacteria are observed at biofuel plants. Airborne cultivable bacteria are often described to be present in clusters or associated with larger particles with an aerodynamic diameter (d(ae)) of 2-8 microm. In this study, we investigate whether airborne fungal components smaller than spore size are present in bioaerosols in working areas at biofuel plants. Furthermore, we measure the exposure to bacteria and fungal components in airborne particulate matter (PM) with a D(50) of 1 microm (called PM(1) dust). PM(1) was sampled using Triplex cyclones at a working area at 14 Danish biofuel plants. Millipore cassettes were used to sample 'total dust'. The PM(1) particles (29 samples) were analysed for content of 11 different components and the total dust was analysed for cultivable fungi, N-acetyl-beta-D-glucosaminidase (NAGase), and (1 --> 3)-beta-D-glucans. In the 29 PM(1) samples, cultivable fungi were found in six samples and with a median concentration below detection level. Using microscopy, fungal spores were identified in 22 samples. The components NAGase and (1 --> 3)-beta-D-glucans, which are mainly associated with fungi, were present in all PM(1) samples. Thermophilic actinomycetes were present in 23 of the 29 PM(1) samples [average = 739 colony-forming units (CFU) m(-3)]. Cultivable and 'total bacteria' were found in average concentrations of, respectively, 249 CFU m(-3) and 1.8 x 10(5) m(-3). DNA- and RNA-containing particles of different lengths were counted by microscopy and revealed a high concentration of particles with a length of 0.5-1.5 microm and only few particles >1.5 microm. The number of cultivable fungi and beta-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 microm, with DNA/RNA-containing particles >1.5 microm, and with other

  19. Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.

    PubMed

    Lewis, Ryan C; Gaffney, Shannon H; Le, Matthew H; Unice, Ken M; Paustenbach, Dennis J

    2012-09-01

    Workers handle catalysts extensively at petroleum refineries throughout the world each year; however, little information is available regarding the airborne concentrations and plausible exposures during this type of work. In this paper, we evaluated the airborne concentrations of 15 metals and total dust generated during solid catalyst loading and unloading operations at one of the largest petroleum refineries in the world using historical industrial hygiene samples collected between 1989 and 2006. The total dust and metals, which included aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, platinum, silicon, silver, vanadium, and zinc, were evaluated in relation to the handling of four different types of solid catalysts associated with three major types of catalytic processes. Consideration was given to the known components of the solid catalysts and any metals that were likely deposited onto them during use. A total of 180 analytical results were included in this analysis, representing 13 personal and 54 area samples. Of the long-term personal samples, airborne concentrations of metals ranged from <0.001 to 2.9mg/m(3), and, in all but one case, resulted in concentrations below the current U.S. Occupational Safety and Health Administration's Permissible Exposure Limits and the American Conference of Governmental Industrial Hygienists' Threshold Limit Values. The arithmetic mean total dust concentration resulting from long-term personal samples was 0.31mg/m(3). The data presented here are the most complete set of its kind in the open literature, and are useful for understanding the potential exposures during solid catalyst handling activities at this petroleum refinery and perhaps other modern refineries during the timeframe examined. PMID:22177528

  20. Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.

    PubMed

    Lewis, Ryan C; Gaffney, Shannon H; Le, Matthew H; Unice, Ken M; Paustenbach, Dennis J

    2012-09-01

    Workers handle catalysts extensively at petroleum refineries throughout the world each year; however, little information is available regarding the airborne concentrations and plausible exposures during this type of work. In this paper, we evaluated the airborne concentrations of 15 metals and total dust generated during solid catalyst loading and unloading operations at one of the largest petroleum refineries in the world using historical industrial hygiene samples collected between 1989 and 2006. The total dust and metals, which included aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, platinum, silicon, silver, vanadium, and zinc, were evaluated in relation to the handling of four different types of solid catalysts associated with three major types of catalytic processes. Consideration was given to the known components of the solid catalysts and any metals that were likely deposited onto them during use. A total of 180 analytical results were included in this analysis, representing 13 personal and 54 area samples. Of the long-term personal samples, airborne concentrations of metals ranged from <0.001 to 2.9mg/m(3), and, in all but one case, resulted in concentrations below the current U.S. Occupational Safety and Health Administration's Permissible Exposure Limits and the American Conference of Governmental Industrial Hygienists' Threshold Limit Values. The arithmetic mean total dust concentration resulting from long-term personal samples was 0.31mg/m(3). The data presented here are the most complete set of its kind in the open literature, and are useful for understanding the potential exposures during solid catalyst handling activities at this petroleum refinery and perhaps other modern refineries during the timeframe examined.

  1. Dust aerosol optical properties using ground-based and airborne lidar in the framework of FENNEC

    NASA Astrophysics Data System (ADS)

    Marnas, Fabien; Chazette, Patrick; Flamant, Cyrille; Royer, Philippe; Boytard, Mai-Lan; Genau, Pascal; Doira, Pascal; Bruneau, Didier; Pelon, Jacques; Sanak, Joseph

    2013-04-01

    The FENNEC program aims to improve our knowledge of both the role of the Saharan Heat Low (SHL) on the West African monsoon and the interactions between the African continent and the Mediterranean basin through the Saharan dust transport. The Saharan desert is the major source of mineral dust in the world and may significantly impact the air quality over the Western Europe by increasing the particular matter content. Two lidar systems were operated by the French component of the FENNEC project: an airborne lidar which was flown aboard the French Falcon 20 research aircraft and a ground-based lidar which was located in the southeastern part of Spain, close to Marbella. The presence of dust in the Saharan atmospheric boundary layer has been easily highlighted using the lidars and confirmed by ground-based sunphotometer and observations from both MODIS and SEVIRI spaceborne instruments. The simultaneous use of the sunphotometer-derived Angstrom exponent and the lidar-derived backscatter to extinction ratio is appeared to be a good approach to separate the optical contribution of dust from local aerosols for the coastal site. Over Spain, the dust layer was mainly located above the planetary boundary layer with several kilometers thick. Over the tropical Atlantic Ocean and the Mauritania the airborne lidar shows a high planetary boundary layer (~5 km above the mean sea level) associated to strong aerosol optical thickness (> 0.8 at 532 nm). The airborne lidar data have been inverted using both MODIS and SEVIRI-derived aerosol optical thickness. The differences between dust optical properties close to and remote from the sources will be discussed.

  2. Factors Affecting Vegetable Growers’ Exposure to Fungal Bioaerosols and Airborne Dust

    PubMed Central

    Hansen, Vinni M.; Meyling, Nicolai Vitt; Winding, Anne; Eilenberg, Jørgen; Madsen, Anne Mette

    2012-01-01

    We have quantified vegetable growers’ exposure to fungal bioaerosol components including (1→3)-β-d-glucan (β-glucan), total fungal spores, and culturable fungal units. Furthermore, we have evaluated factors that might affect vegetable growers’ exposure to fungal bioaerosols and airborne dust. Investigated environments included greenhouses producing cucumbers and tomatoes, open fields producing cabbage, broccoli, and celery, and packing facilities. Measurements were performed at different times during the growth season and during execution of different work tasks. Bioaerosols were collected with personal and stationary filter samplers. Selected fungal species (Beauveria spp., Trichoderma spp., Penicillium olsonii, and Penicillium brevicompactum) were identified using different polymerase chain reaction-based methods and sequencing. We found that the factors (i) work task, (ii) crop, including growth stage of handled plant material, and (iii) open field versus greenhouse significantly affected the workers’ exposure to bioaerosols. Packing of vegetables and working in open fields caused significantly lower exposure to bioaerosols, e.g. mesophilic fungi and dust, than harvesting in greenhouses and clearing of senescent greenhouse plants. Also removing strings in cucumber greenhouses caused a lower exposure to bioaerosols than harvest of cucumbers while removal of old plants caused the highest exposure. In general, the exposure was higher in greenhouses than in open fields. The exposures to β-glucan during harvest and clearing of senescent greenhouse plants were very high (median values ranging between 50 and 1500 ng m−3) compared to exposures reported from other occupational environments. In conclusion, vegetable growers’ exposure to bioaerosols was related to the environment, in which they worked, the investigated work tasks, and the vegetable crop. PMID:22003240

  3. Collection of cosmic dust in earth orbit for exobiological analysis

    NASA Technical Reports Server (NTRS)

    Fogleman, Guy; Huntington, Judith L.; Carle, Glenn C.

    1989-01-01

    Two proposed NASA exobiology flight experiments are described in terms of the approaches to cosmic dust collection and the issues addressed by the analysis of the samples. A passive collector is planned for use with the Cosmic Dust Collection Facility, and an active system is described for attachment to the Space Station Freedom payload. Exobiological study of cosmic dust could provide insights on organic chemistry in the grains and on the relative abundances of biogenic elements in interstellar, cometary, and meteoric samples.

  4. Mineralogy of Interplanetary Dust Particles from the Comet Giacobini-Zinner Dust Stream Collections

    NASA Technical Reports Server (NTRS)

    Nakamura-Messenger, K.; Messenger, S.; Westphal, A. J.; Palma, R. L.

    2015-01-01

    The Draconoid meteor shower, originating from comet 21P/Giacobini-Zinner, is a low-velocity Earth-crossing dust stream that had a peak anticipated flux on Oct. 8, 2012. In response to this prediction, NASA performed dedicated stratospheric dust collections to target interplanetary dust particles (IDPs) from this comet stream on Oct 15-17, 2012 [3]. Twelve dust particles from this targeted collection were allocated to our coordinated analysis team for studies of noble gas (Univ. Minnesota, Minnesota State Univ.), SXRF and Fe-XANES (SSL Berkeley) and mineralogy/isotopes (JSC). Here we report a mineralogical study of 3 IDPs from the Draconoid collection..

  5. Characterisation of airborne particles collected within and proximal to an opencast coalmine: South Wales, U.K.

    PubMed

    Jones, Tim; Blackmore, Pete; Leach, Matt; Bérubé, Kelly; Sexton, Keith; Richards, Roy

    2002-05-01

    Airborne particulate matter has been collected from within, and proximal to, an opencast coal mine in south Wales. This work forms the first part of a three year project to collect and characterise, then determine the possible toxicology of airborne particles in the south Wales region. High-resolution Field Emission SEM has shown that the coal mine dusts consist largely of an assemblage of mineral grains and vehicle exhaust particles. SEM-EDX has shown that the mineralogical make-up of the PM10 is complex, heterogeneous, and constantly changing. These findings are supported by analytical TEM-EPXMA. However, patterns can be determined relating the mineralogical composition of the airborne particles to collection locations and mining activities within the opencast. At our study opencast, Park Slip West, quartz, which has known health effects, never exceeded 30% of the total collection mass, and average levels were much less. Vehicle exhaust emissions was the largest source in terms of particle numbers. The mass of airborne particulate matter within the pit averaged approximately twice that of outside the pit: importantly however, this higher mass was due to relatively large, and non-respirable, mineral grains. This study demonstrates that the physicochemical and mineralogical characterisation of airborne particles from mining and quarrying is essential to quantify the respirable fraction, and to identify potentially hazardous components within the PM10. PMID:12004982

  6. Characterisation of airborne particles collected within and proximal to an opencast coalmine: South Wales, U.K.

    PubMed

    Jones, Tim; Blackmore, Pete; Leach, Matt; Bérubé, Kelly; Sexton, Keith; Richards, Roy

    2002-05-01

    Airborne particulate matter has been collected from within, and proximal to, an opencast coal mine in south Wales. This work forms the first part of a three year project to collect and characterise, then determine the possible toxicology of airborne particles in the south Wales region. High-resolution Field Emission SEM has shown that the coal mine dusts consist largely of an assemblage of mineral grains and vehicle exhaust particles. SEM-EDX has shown that the mineralogical make-up of the PM10 is complex, heterogeneous, and constantly changing. These findings are supported by analytical TEM-EPXMA. However, patterns can be determined relating the mineralogical composition of the airborne particles to collection locations and mining activities within the opencast. At our study opencast, Park Slip West, quartz, which has known health effects, never exceeded 30% of the total collection mass, and average levels were much less. Vehicle exhaust emissions was the largest source in terms of particle numbers. The mass of airborne particulate matter within the pit averaged approximately twice that of outside the pit: importantly however, this higher mass was due to relatively large, and non-respirable, mineral grains. This study demonstrates that the physicochemical and mineralogical characterisation of airborne particles from mining and quarrying is essential to quantify the respirable fraction, and to identify potentially hazardous components within the PM10.

  7. Airborne dust transport to the eastern Pacific Ocean off southern California: Evidence from San Clemente Island

    USGS Publications Warehouse

    Muhs, D.R.; Budahn, J.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.

    2007-01-01

    Islands are natural dust traps, and San Clemente Island, California, is a good example. Soils on marine terraces cut into Miocene andesite on this island are clay-rich Vertisols or Alfisols with vertic properties. These soils are overlain by silt-rich mantles, 5-20 cm thick, that contrast sharply with the underlying clay-rich subsoils. The silt mantles have a mineralogy that is distinct from the island bedrock. Silt mantles are rich in quartz, which is rare in the island andesite. The clay fraction of the silt mantles is dominated by mica, also absent from local andesite, and contrasts with the subsoils, dominated by smectite. Ternary plots of immobile trace elements (Sc-Th-La and Ta-Nd-Cr) show that the island andesite has a composition intermediate between average upper continental crust and average oceanic crust. In contrast, the silt and, to a lesser extent, clay fractions of the silt mantles have compositions closer to average upper continental crust. The silt mantles have particle size distributions similar to loess and Mojave Desert dust, but are coarser than long-range-transported Asian dust. We infer from these observations that the silt mantles are derived from airborne dust from the North American mainland, probably river valleys in the coastal mountains of southern California and/or the Mojave Desert. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. Examination of satellite imagery shows that easterly Santa Ana winds carry abundant dust to the eastern Pacific Ocean and the California Channel Islands. Airborne dust from mainland North America may be an important component of the offshore sediment budget in the easternmost Pacific Ocean, a finding of potential biogeochemical and climatic significance.

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

    PubMed Central

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

    1995-01-01

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

  9. Airborne and Grain Dust Fungal Community Compositions Are Shaped Regionally by Plant Genotypes and Farming Practices

    PubMed Central

    Pellissier, Loïc; Oppliger, Anne; Hirzel, Alexandre H.; Savova-Bianchi, Dessislava; Mbayo, Guilain; Mascher, Fabio; Kellenberger, Stefan

    2016-01-01

    Chronic exposure to airborne fungi has been associated with different respiratory symptoms and pathologies in occupational populations, such as grain workers. However, the homogeneity in the fungal species composition of these bioaerosols on a large geographical scale and the different drivers that shape these fungal communities remain unclear. In this study, the diversity of fungi in grain dust and in the aerosols released during harvesting was determined across 96 sites at a geographical scale of 560 km2 along an elevation gradient of 500 m by tag-encoded 454 pyrosequencing of the internal transcribed spacer (ITS) sequences. Associations between the structure of fungal communities in the grain dust and different abiotic (farming system, soil characteristics, and geographic and climatic parameters) and biotic (wheat cultivar and previous crop culture) factors were explored. These analyses revealed a strong relationship between the airborne and grain dust fungal communities and showed the presence of allergenic and mycotoxigenic species in most samples, which highlights the potential contribution of these fungal species to work-related respiratory symptoms of grain workers. The farming system was the major driver of the alpha and beta phylogenetic diversity values of fungal communities. In addition, elevation and soil CaCO3 concentrations shaped the alpha diversity, whereas wheat cultivar, cropping history, and the number of freezing days per year shaped the taxonomic beta diversity of these communities. PMID:26826229

  10. Airborne and Grain Dust Fungal Community Compositions Are Shaped Regionally by Plant Genotypes and Farming Practices.

    PubMed

    Pellissier, Loïc; Oppliger, Anne; Hirzel, Alexandre H; Savova-Bianchi, Dessislava; Mbayo, Guilain; Mascher, Fabio; Kellenberger, Stefan; Niculita-Hirzel, Hélène

    2016-04-01

    Chronic exposure to airborne fungi has been associated with different respiratory symptoms and pathologies in occupational populations, such as grain workers. However, the homogeneity in the fungal species composition of these bioaerosols on a large geographical scale and the different drivers that shape these fungal communities remain unclear. In this study, the diversity of fungi in grain dust and in the aerosols released during harvesting was determined across 96 sites at a geographical scale of 560 km(2) along an elevation gradient of 500 m by tag-encoded 454 pyrosequencing of the internal transcribed spacer (ITS) sequences. Associations between the structure of fungal communities in the grain dust and different abiotic (farming system, soil characteristics, and geographic and climatic parameters) and biotic (wheat cultivar and previous crop culture) factors were explored. These analyses revealed a strong relationship between the airborne and grain dust fungal communities and showed the presence of allergenic and mycotoxigenic species in most samples, which highlights the potential contribution of these fungal species to work-related respiratory symptoms of grain workers. The farming system was the major driver of the alpha and beta phylogenetic diversity values of fungal communities. In addition, elevation and soil CaCO3 concentrations shaped the alpha diversity, whereas wheat cultivar, cropping history, and the number of freezing days per year shaped the taxonomic beta diversity of these communities. PMID:26826229

  11. Analysis of Potentially Toxic Metals in Airborne Cement Dust Around Sagamu, Southwestern Nigeria

    NASA Astrophysics Data System (ADS)

    Gbadebo, A. M.; Bankole, O. D.

    This study analyzed the concentration levels of potentially toxic and harmful elements contained in the airborne cement dust generated in the vicinity and farther away 500 m in the conventional four cardinal directions from the West African Portland Cement Company (WAPCO) factory mill, Sagamu. The results indicated that the concentration range of these toxic elements fall between 40.0 and 280,000 μg g-1 in the cement dust samples. Also, the concentration range of these toxic elements in 1 L of air samples varies between 0.01 μg g-1 and 29.92 μg L-1. The results generally show elevated concentrations of all the elements when compared with USA threshold limit of particulate mental concentration (e.g., Pb (1.5 g m-3); Cd (0.004-0.026 g m-3) in the air. These elements in the airborne cement dusts may pose a great threat to the health of plants, animals and residents in and around the factory and also to workers and visitors to the factory.

  12. Sensory and other neurogenic effects of exposures to airborne office dust

    NASA Astrophysics Data System (ADS)

    Mølhave, L.; Kjærgaard, S. K.; Attermann, J.

    This Danish Office Dust Experiment investigated the response of 24 healthy non-sensitive adult subjects to exposure to normal office dust in the air (7 μg m -3 clean air, 136 and 390 μg m -3 TSP). The dust had no major identifiable specific reactive components. The exposure duration was 5 1/4 h and was arranged in a climate chamber in controlled atmospheric conditions. Measurements were made acutely at exposure onset, subacutely at exposure end and next day (late). As secondary aims the time course and threshold of any observed effect of the exposures, and the characteristics of any hyperresponding subgroup were investigated. In a questionnaire with 36 questions the dust exposures caused increased acute, subacute and late perceptions of reduced air quality, acute and subacute increased odor intensity, acute eye irritation, acute and late heavy head, subacute feeling of perspiration, and subacute general irritation. Cough increased subacutely during exposures. In addition, a performance test showed effects of dust exposures which also affected "Mood Scale" ratings. No effect was seen on an addition test for distraction, and objective measurements of skin humidity. The overall conclusion of the study is that healthy subjects without hypersensitivity reactions seem to respond to airborne house dust. The responses are both subjective sensory reactions and other neurogenic effects even at exposure levels within the range found in normal buildings. Some of the effects appeared acutely and decreased through adaptation while others increased during prolonged exposure and remained for more than 17 h after the exposure ended. The findings may indicate for this type of dust a threshold level for the dose-response relationships below 140 μg m -3.

  13. Effect of ultraviolet on the survival of bacteria airborne in simulated Martian dust clouds.

    PubMed

    Hagen, C A; Hawrylewicz, E J; Anderson, B T; Cephus, M L

    1970-01-01

    A chamber was constructed to create simulated Martian dust storms and thereby study the survival of airborne micro-organisms while exposed to the rigors of the Martian environment, including ultraviolet irradiation. Representative types of sporeforming and non-sporeforming bacteria present in spacecraft assembly areas and indigenous to humans were studied. It was found that daily ultraviolet irradiation of 2 to 9 X 10(7) erg cm-2 was not sufficient to sterilize the dust clouds. The soil particles protected the organisms from ultraviolet irradiation since the numbers of survivors from irradiated environments were similar to those from unirradiated environments. Pending further data of the Martian environment, the contamination and dissemination of Mars with terrestrial micro-organisms is still a distinct possibility.

  14. Airborne Fungal and Bacterial Components in PM1 Dust from Biofuel Plants

    PubMed Central

    Madsen, Anne Mette; Schlünssen, Vivi; Olsen, Tina; Sigsgaard, Torben; Avci, Hediye

    2009-01-01

    Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size (<1.5 μm). High exposures to fungi and bacteria are observed at biofuel plants. Airborne cultivable bacteria are often described to be present in clusters or associated with larger particles with an aerodynamic diameter (dae) of 2–8 μm. In this study, we investigate whether airborne fungal components smaller than spore size are present in bioaerosols in working areas at biofuel plants. Furthermore, we measure the exposure to bacteria and fungal components in airborne particulate matter (PM) with a D50 of 1 μm (called PM1 dust). PM1 was sampled using Triplex cyclones at a working area at 14 Danish biofuel plants. Millipore cassettes were used to sample ‘total dust’. The PM1 particles (29 samples) were analysed for content of 11 different components and the total dust was analysed for cultivable fungi, N-acetyl-β-D-glucosaminidase (NAGase), and (1 → 3)-β-D-glucans. In the 29 PM1 samples, cultivable fungi were found in six samples and with a median concentration below detection level. Using microscopy, fungal spores were identified in 22 samples. The components NAGase and (1 → 3)-β-D-glucans, which are mainly associated with fungi, were present in all PM1 samples. Thermophilic actinomycetes were present in 23 of the 29 PM1 samples [average = 739 colony-forming units (CFU) m−3]. Cultivable and ‘total bacteria’ were found in average concentrations of, respectively, 249 CFU m−3 and 1.8 × 105 m−3. DNA- and RNA-containing particles of different lengths were counted by microscopy and revealed a high concentration of particles with a length of 0.5–1.5 μm and only few particles >1.5 μm. The number of cultivable fungi and β-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 μm, with DNA/RNA-containing particles >1.5 μm, and with other fungal components in PM1

  15. Collation of earth resources data collected by ERIM airborne sensors

    NASA Technical Reports Server (NTRS)

    Hasell, P. G., Jr.

    1975-01-01

    Earth resources imagery from nine years of data collection with developmental airborne sensors is cataloged for reference. The imaging sensors include single and multiband line scanners and side-looking radars. The operating wavelengths of the sensors include ultraviolet, visible and infrared band scanners, and X- and L-band radar. Imagery from all bands (radar and scanner) were collected at some sites and many sites had repeated coverage. The multiband scanner data was radiometrically calibrated. Illustrations show how the data can be used in earth resource investigations. References are made to published reports which have made use of the data in completed investigations. Data collection sponsors are identified and a procedure described for gaining access to the data.

  16. 78 FR 54956 - Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

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

  17. Machine vision based particle size and size distribution determination of airborne dust particles of wood and bark pellets

    SciTech Connect

    Igathinathane, C; Pordesimo, L.O.

    2009-08-01

    Dust management strategies in industrial environment, especially of airborne dust, require quantification and measurement of size and size distribution of the particles. Advanced specialized instruments that measure airborne particle size and size distribution apply indirect methods that involve light scattering, acoustic spectroscopy, and laser diffraction. In this research, we propose a simple and direct method of airborne dust particle dimensional measurement and size distribution analysis using machine vision. The method involves development of a user-coded ImageJ plugin that measures particle length and width and analyzes size distribution of particles based on particle length from high-resolution scan images. Test materials were airborne dust from soft pine wood sawdust pellets and ground pine tree bark pellets. Subsamples prepared by dividing the actual dust using 230 mesh (63 m) sieve were analyzed as well. A flatbed document scanner acquired the digital images of the dust particles. Proper sampling, layout of dust particles in singulated arrangement, good contrast smooth background, high resolution images, and accurate algorithm are essential for reliable analysis. A halo effect around grey-scale images ensured correct threshold limits. The measurement algorithm used Feret s diameter for particle length and pixel-march technique for particle width. Particle size distribution was analyzed in a sieveless manner after grouping particles according to their distinct lengths, and several significant dimensions and parameters of particle size distribution were evaluated. Results of the measurement and analysis were presented in textual and graphical formats. The developed plugin was evaluated to have a dimension measurement accuracy in excess of 98.9% and a computer speed of analysis of <8 s/image. Arithmetic mean length of actual wood and bark pellets airborne dust particles were 0.1138 0.0123 and 0.1181 0.0149 mm, respectively. The airborne dust particles of

  18. Airborne radionuclides in mosses collected at different latitudes.

    PubMed

    Krmar, M; Wattanavatee, K; Radnović, D; Slivka, J; Bhongsuwan, T; Frontasyeva, M V; Pavlov, S S

    2013-03-01

    Terrestrial mosses are a promising medium for investigation and monitoring of airborne radionuclide depositions due to their widespread occurrence, ease of sampling, and the possibility of high-resolution gamma spectrometry measurements without preparatory chemical treatment of samples. The overall objective of the present study was to compare (7)Be, (210)Pb and (137)Cs activity concentrations (in Bq/kg) in moss samples collected at two different climate zones: the south of Thailand (7 °N) and in Serbia (∼45 °N) in order to examine deposition of airborne radionuclide in these distant areas. Significant difference of the (210)Pb content (almost a factor of 2) in mosses was observed. The mean value of (7)Be activity in samples from Serbia was almost 40% higher than activity of those collected in Thailand. Level of (137)Cs in Thailand mosses was below the detection limit. It was shown that air transport of water droplets in the area of waterfalls and strong turbulence can deposit U and Th daughter nuclei. PMID:21880403

  19. Airborne radionuclides in mosses collected at different latitudes.

    PubMed

    Krmar, M; Wattanavatee, K; Radnović, D; Slivka, J; Bhongsuwan, T; Frontasyeva, M V; Pavlov, S S

    2013-03-01

    Terrestrial mosses are a promising medium for investigation and monitoring of airborne radionuclide depositions due to their widespread occurrence, ease of sampling, and the possibility of high-resolution gamma spectrometry measurements without preparatory chemical treatment of samples. The overall objective of the present study was to compare (7)Be, (210)Pb and (137)Cs activity concentrations (in Bq/kg) in moss samples collected at two different climate zones: the south of Thailand (7 °N) and in Serbia (∼45 °N) in order to examine deposition of airborne radionuclide in these distant areas. Significant difference of the (210)Pb content (almost a factor of 2) in mosses was observed. The mean value of (7)Be activity in samples from Serbia was almost 40% higher than activity of those collected in Thailand. Level of (137)Cs in Thailand mosses was below the detection limit. It was shown that air transport of water droplets in the area of waterfalls and strong turbulence can deposit U and Th daughter nuclei.

  20. Martian Dust Collected by Phoenix's Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image from NASA's Phoenix Lander's Optical Microscope shows particles of Martian dust lying on the microscope's silicon substrate. The Robotic Arm sprinkled a sample of the soil from the Snow White trench onto the microscope on July 2, 2008, the 38th Martian day, or sol, of the mission after landing.

    Subsequently, the Atomic Force Microscope, or AFM, zoomed in one of the fine particles, creating the first-ever image of a particle of Mars' ubiquitous fine dust, the most highly magnified image ever seen from another world.

    The Atomic Force Microscope was developed by a Swiss-led consortium in collaboration with Imperial College London. The AFM is part of Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer instrument.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  1. Real-time PCR detection of toxigenic Fusarium in airborne and settled grain dust and associations with trichothecene mycotoxins.

    PubMed

    Halstensen, Anne Straumfors; Nordby, Karl-Christian; Eduard, Wijnand; Klemsdal, Sonja Sletner

    2006-12-01

    Inhalation of immunomodulating mycotoxins produced by Fusarium spp. that are commonly found in grain dust may imply health risks for grain farmers. Airborne Fusarium and mycotoxin exposure levels are mainly unknown due to difficulties in identifying Fusarium and mycotoxins in personal aerosol samples. We used a novel real-time PCR method to quantify the fungal trichodiene synthase gene (tri5) and DNA specific to F. langsethiae and F. avenaceum in airborne and settled grain dust, determined the personal inhalant exposure level to toxigenic Fusarium during various activities, and evaluated whether quantitative measurements of Fusarium-DNA could predict trichothecene levels in grain dust. Airborne Fusarium-DNA was detected in personal samples even from short tasks (10-60 min). The median Fusarium-DNA level was significantly higher in settled than in airborne grain dust (p < 0.001), and only the F. langsethiae-DNA levels correlated significantly in settled and airborne dust (r(s) = 0.20, p = 0.003). Both F. langsethiae-DNA and tri5-DNA were associated with HT-2 and T-2 toxins (r(s) = 0.24-0.71, p < 0.05 to p < 00.01) in settled dust, and could thus be suitable as indicators for HT-2 and T-2. The median personal inhalant exposure to specific toxigenic Fusarium spp. was less than 1 genome m(-3), but the exposure ranged from 0-10(5) genomes m(-3). This study is the first to apply real-time PCR on personal samples of inhalable grain dust for the quantification of tri5 and species-specific Fusarium-DNA, which may have potential for risk assessments of inhaled trichothecenes. PMID:17133280

  2. Airborne Sunphotometry of African Dust and Marine Boundary Layer Aerosols in PRIDE

    NASA Technical Reports Server (NTRS)

    Livingston, John M.; Redemann, Jens; Russell, Philip; Schmid, Beat; Reid, Jeff; Pilewskie, Peter; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    The Puerto Rico Dust Experiment (PRIDE) was conducted during summer 2000 to study the radiative, microphysical and transport properties of Saharan dust in the Caribbean region. During PRIDE, NASA Ames Research Center's six-channel airborne autotracking sunphotometer (AATS-6) was operated aboard a Piper Navajo airplane based at Roosevelt Roads Naval Station on the northeast coast of Puerto Rico. AATS-6 measurements were taken during 21 science flights off the coast of Puerto Rico in the western Caribbean. Data were acquired within and above the Marine Boundary Layer (MBL) and the Saharan Aerosol Layer (SAL) up to 5.5 km altitude tinder a wide range of dust loadings. Aerosol optical depth (AOD) spectra and columnar water vapor (CWV) values have been calculated from the AATS-6 measurements by using sunphotometer calibration data obtained at Mauna Loa Observatory (3A kin ASL) before (May) and after (October) PRIDE. Mid-visible AOD values measured near the surface during PRIDE ranged from 0.07 on the cleanest day to 0.55 on the most turbid day. Values measured above the MBL were as high as 0.35; values above the SAL were as low as 0.01. The fraction of total column AOD due to Saharan dust cannot be determined precisely from AATS-6 AOD data alone due to the uncertainty in the extent of vertical mixing of the dust down through the MBL. However, analyses of ground-based and airborne in-situ aerosol sampling measurements and ground-based aerosol lidar backscatter data should yield accurate characterization of the vertical mixing that will enable calculation of the Saharan dust AOD component from the sunphotometer data. Examples will be presented showing measured AATS-6 AOD spectra, calculated aerosol extinction and water vapor density vertical profiles, and aerosol size distributions retrieved by inversion of the AOD spectra. Near sea-surface AOD spectra acquired by AATS-6 during horizontal flight legs at 30 m ASL are available for validation of AOD derived from coincident

  3. Physics of Interplanetary Dust Collection with Aerogel

    NASA Technical Reports Server (NTRS)

    Anderson, William W.

    1998-01-01

    This report presents the results of research undertaken to study various problems associated with hypervelocity capture of dust particles in aerogel. The primary topics investigated were the properties of shocked aerogel and the requirements for reliable capture of particles on the STARDUST mission. In particular, the viscosity of shocked aerogel has been an open question. The results presented here suggest that the viscosity of aerogel at high impact velocities is negligible, although there remains some uncertainty about lower velocities. The model adopted for viscosity treats the mixture of polymeric silica and decomposition products and finds that, for particle velocities of 6-7 km/s, the viscosity is similar to that typical of light gasses at STP. Expressions for the Hugoniot of aerogel as a function of density were also obtained from the available data. All aerogels of interest for cosmic dust collectors have very similar shock velocity-particle velocity Hugoniot curves. The strength behavior of aerogel for low-speed penetration was measured, but further work is needed to study the proper way to apply this to the issue of terminal deceleration of a dust particle. Preliminary calculations designed to maximize the penetration depths were performed to determine the required density of aerogel to reliably stop a particle in a 3 cm thickness of aerogel (the path length expected for a normal impact into the STARDUST collector). In order to stop a particle of density rho(sub p) and diameter d(sub p), the mean density of the aerogel collector should be no less than that given by the expression bar rho(sub 0) = 1.085 X 10(exp -4 )rho(sub p)d(sub p), for densities measured in g/ cu cm and the particle diameter measured in micrometers.

  4. Optical spectroscopy of interplanetary dust collected in the earth's stratosphere

    NASA Technical Reports Server (NTRS)

    Fraundorf, P.; Patel, R. I.; Shirck, J.; Walker, R. M.; Freeman, J. J.

    1980-01-01

    Optical absorption spectra of interplanetary dust particles 2-30 microns in size collected in the atmosphere at an altitude of 20 km by inertial impactors mounted on NASA U-2 aircraft are reported. Fourier transform absorption spectroscopy of crushed samples of the particles reveals a broad feature in the region 1300-800 kaysers which has also been found in meteorite and cometary dust spectra, and a weak iron crystal field absorption band at approximately 9800 kaysers, as is observed in meteorites. Work is currently in progress to separate the various components of the interplanetary dust particles in order to evaluate separately their contributions to the absorption.

  5. An airborne meteorological data collection system using satellite relay (ASDAR)

    NASA Technical Reports Server (NTRS)

    Bagwell, J. W.; Lindow, B. G.

    1978-01-01

    The National Aeronautics and Space Administration (NASA) has developed an airborne data acquisition and communication system for the National Oceanic and Atmospheric Administration (NOAA). This system known as ASDAR, the Aircraft to Satellite Data Relay, consists of a microprocessor based controller, time clock, transmitter and antenna. Together they acquire meteorological and position information from existing aircraft systems on B-747 aircraft, convert and format these, and transmit them to the ground via the GOES meteorological satellite series. The development and application of the ASDAR system is described with emphasis on unique features. Performance to date is exceptional, providing horizon-to-horizon coverage of aircraft flights. The data collected is of high quality and is considered a valuable addition to the data base from which NOAA generates its weather forecasts.

  6. Classification of the Johnson Space Center stratospheric dust collection

    NASA Technical Reports Server (NTRS)

    Mackinnon, I. D. R.; Mckay, D. S.; Nace, G.; Isaacs, A. M.

    1982-01-01

    Data on the nature of dust in the upper atmosphere have been provided by a stratospheric dust collection program. This program makes it possible to study in detail materials related to early solar system history. A comprehensive overview of the stratospheric collection program provides a basis for a better understanding of stratospheric dust origins. It is important for the development of this understanding that easily accessible criteria for classification be established. The present investigation is concerned with the development of a suitable classification scheme for the obtained stratospheric materials. Three sets of eight collectors were flown on WB57 high-altitude aircraft during August and September, 1981, as part of the considered collection program. Three of the 24 impactors (flags) have undergone preliminary examination. The current investigation is concerned with selected data on materials from flags W7010, W7017, and W7029.

  7. Heavy Metal Content in Airborne Dust of Childhood Leukemia Cluster Areas: Even Small Towns Have Air Pollutants

    NASA Astrophysics Data System (ADS)

    Sheppard, P. R.; Witten, M. L.

    2004-12-01

    Currently in the US, there are at least two ongoing clusters of childhood leukemia, where the incidence rate over the last several years has exceeded the national norm. In Fallon, Nevada, a town of 8,000 people, 16 children have been diagnosed with leukemia since 1995, three of whom have died. In Sierra Vista, Arizona, a town of 38,000 people, 12 children have been diagnosed since 1998, two of whom have died. A possible third cluster of childhood leukemia and other cancers is being monitored in Elk Grove, California, a suburb of Sacramento. For the purpose of characterizing the heavy metal content of airborne dust of these three communities, total suspended particulate samples were collected from each town as well as from nearby towns that could be considered as control comparisons. Sampling was done using portable high-volume blowers and glass- or quartz-fiber filter media. Filters were measured for elemental concentrations using inductively coupled plasma mass spectroscopy. To date, our most notable results are from the Nevada region. Compared to other control towns in the region, Fallon had significantly more tungsten in its airborne dust. Uranium was also higher in dust of Fallon than in other control towns. Uranium is a known health hazard, though it is not necessarily specifically related to childhood leukemia. The role of tungsten in childhood leukemia has not been widely studied. However, other research has identified tungsten exposure as an environmental concern in Fallon. A CDC study of human tissue samples from Fallon has shown high tungsten levels in people of Fallon, and a USGS study of drinking water in Fallon also has shown high tungsten there. Tree-ring research on selected trees has shown high tungsten values in recent rings compared to earlier rings. While these multiple indications of tungsten in the Fallon environment do not directly lead to the conclusion that tungsten causes leukemia, they do combine to suggest that biomedical research on the

  8. Cosmic Dust Collection Facility: Scientific objectives and programmatic relations

    NASA Technical Reports Server (NTRS)

    Hoerz, Fred (Editor); Brownlee, D. E.; Bunch, T. E.; Grounds, D.; Grun, E.; Rummel, Y.; Quaide, W. L.; Walker, R. M.

    1990-01-01

    The science objectives are summarized for the Cosmic Dust Collection Facility (CDCF) on Space Station Freedom and these objectives are related to ongoing science programs and mission planning within NASA. The purpose is to illustrate the potential of the CDCF project within the broad context of early solar system sciences that emphasize the study of primitive objects in state-of-the-art analytical and experimental laboratories on Earth. Current knowledge about the sources of cosmic dust and their associated orbital dynamics is examined, and the results are reviewed of modern microanalytical investigations of extraterrestrial dust particles collected on Earth. Major areas of scientific inquiry and uncertainty are identified and it is shown how CDCF will contribute to their solution. General facility and instrument concepts that need to be pursued are introduced, and the major development tasks that are needed to attain the scientific objectives of the CDCF project are identified.

  9. Progress toward a cosmic dust collection facility on space station

    NASA Technical Reports Server (NTRS)

    Mackinnon, Ian D. R. (Editor); Carey, William C. (Editor)

    1987-01-01

    Scientific and programmatic progress toward the development of a cosmic dust collection facility (CDCF) for the proposed space station is documented. Topics addressed include: trajectory sensor concepts; trajectory accuracy and orbital evolution; CDCF pointing direction; development of capture devices; analytical techniques; programmatic progress; flight opportunities; and facility development.

  10. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    SciTech Connect

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-15

    Radioactive fission product {sup 131}I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, {sup 134}Cs and {sup 137}Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m{sup -3} in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of {sup 134}Cs and {sup 137}Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m{sup -3}) variation of stable cesium ({sup 133}Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  11. Correlation between Asian Dust and Specific Radioactivities of Fission Products Included in Airborne Samples in Tokushima, Shikoku Island, Japan, Due to the Fukushima Nuclear Accident

    NASA Astrophysics Data System (ADS)

    Sakama, M.; Nagano, Y.; Kitade, T.; Shikino, O.; Nakayama, S.

    2014-06-01

    Radioactive fission product 131I released from the Fukushima Daiichi Nuclear Power Plants (FD-NPP) was first detected on March 23, 2011 in an airborne aerosol sample collected at Tokushima, Shikoku Island, located in western Japan. Two other radioactive fission products, 134Cs and 137Cs were also observed in a sample collected from April 2 to 4, 2011. The maximum specific radioactivities observed in this work were about 2.5 to 3.5 mBq×m-3 in a airborne aerosol sample collected on April 6. During the course of the continuous monitoring, we also made our first observation of seasonal Asian Dust and those fission products associated with the FDNPP accident concurrently from May 2 to 5, 2011. We found that the specific radioactivities of 134Cs and 137Cs decreased drastically only during the period of Asian Dust. And also, it was found that this trend was very similar to the atmospheric elemental concentration (ng×m-3) variation of stable cesium (133Cs) quantified by elemental analyses using our developed ICP-DRC-MS instrument.

  12. Investigation of bacterial effects of Asian dust events through comparison with seasonal variability in outdoor airborne bacterial community

    PubMed Central

    Park, Jonguk; Ichijo, Tomoaki; Nasu, Masao; Yamaguchi, Nobuyasu

    2016-01-01

    Atmospheric bacterial dispersion with aeolian dust has been reported to have a potential impact on public health and ecosystems. Asian dust is a major aeolian event that results in an estimated 4 million tons of Asian dust particles falling in Japan annually, 3,000–5,000 km away from their source regions. However, most studies have only investigated the effects of Asian dust during dust seasons. Therefore, in this study, outdoor bacterial abundance and community composition were determined by 16S rRNA quantitative PCR and amplicon sequencing, respectively, and compared on Asian and non-Asian dust days (2013–2015; 44 samples over four seasons). Seasonal variations in bacterial abundance of non-Asian dust days were not observed. Bacterial abundance of individual samples collected on non-Asian dust days changed dynamically relative to Asian dust days, with bacterial abundance occasionally reaching those of Asian dust days. The bacterial community composition on non-Asian dust days was rather stable seasonally, and did not differ from that on Asian dust days. These results indicate that bacteria in Asian dust does not immediately influence indigenous bacterial communities at the phylum/class level in distant downwind areas; accordingly, further studies of bacterial communities in downwind areas closer to the dust source are warranted. PMID:27761018

  13. Airborne Dust Cloud Measurements at the INL National Security Test Range

    SciTech Connect

    Michael L. Abbott; Norm Stanley; Larry Radke; Charles Smeltzer

    2007-09-01

    On July 11, 2007, a surface, high-explosive test (<20,000 lb TNT-equivalent) was carried out at the National Security Test Range (NSTR) on the Idaho National Laboratory (INL) Site. Aircraft-mounted rapid response (1-sec) particulate monitors were used to measure airborne PM-10 concentrations directly in the dust cloud and to develop a PM-10 emission factor that could be used for subsequent tests at the NSTR. The blast produced a mushroom-like dust cloud that rose approximately 2,500–3,000 ft above ground level, which quickly dissipated (within 5 miles of the source). In general, the cloud was smaller and less persistence than expected, or that might occur in other areas, likely due to the coarse sand and subsurface conditions that characterize the immediate NSTR area. Maximum short time-averaged (1-sec) PM-10 concentrations at the center of the cloud immediately after the event reached 421 µg m-3 but were rapidly reduced (by atmospheric dispersion and fallout) to near background levels (~10 µg m-3) after about 15 minutes. This occurred well within the INL Site boundary, about 8 km (5 miles) from the NSTR source. These findings demonstrate that maximum concentrations in ambient air beyond the INL Site boundary (closest is 11.2 km from NSTR) from these types of tests would be well within the 150 µg m-3 24-hour National Ambient Air Quality Standards for PM-10. Aircraft measurements and geostatistical techniques were used to successfully quantify the initial volume (1.64E+9 m3 or 1.64 km3) and mass (250 kg) of the PM-10 dust cloud, and a PM-10 emission factor (20 kg m-3 crater soil volume) was developed for this specific type of event at NSTR. The 250 kg of PM-10 mass estimated from this experiment is almost seven-times higher than the 36 kg estimated for the environmental assessment (DOE-ID 2007) using available Environmental Protection Agency (EPA 1995) emission factors. This experiment demonstrated that advanced aircraft-mounted instruments operated by

  14. Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California

    USGS Publications Warehouse

    Muhs, D.R.; Budahn, J.R.; Johnson, D.L.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.; Jones, J.A.

    2008-01-01

    There is an increasing awareness that dust plays important roles in climate change, biogeochemical cycles, nutrient supply to ecosystems, and soil formation. In Channel Islands National Park, California, soils are clay-rich Vertisols or Alfisols and Mollisols with vertic properties. The soils are overlain by silt-rich mantles that contrast sharply with the underlying clay-rich horizons. Silt mantles contain minerals that are rare or absent in the volcanic rocks that dominate these islands. Immobile trace elements (Sc-Th-La and Ta-Nd-Cr) and rare-earth elements show that the basalt and andesite on the islands have a composition intermediate between upper-continental crust and oceanic crust. In contrast, the silt fractions and, to a lesser extent, clay fractions of the silt mantle have compositions closer to average upper-continental crust and very similar to Mojave Desert dust. Island shelves, exposed during the last glacial period, could have provided a source of eolian sediment for the silt mantles, but this is not supported by mineralogical data. We hypothesize that a more likely source for the silt-rich mantles is airborne dust from mainland California and Baja California, either from the Mojave Desert or from the continental shelf during glacial low stands of sea. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. The eolian silt mantles constitute an important medium of plant growth and provide evidence that abundant eolian silt and clay may be delivered to the eastern Pacific Ocean from inland desert sources. ?? 2007 Geological Society of America.

  15. Separating Dust Mixtures and Other External Aerosol Mixtures Using Airborne High Spectral Resolution Lidar Data

    NASA Astrophysics Data System (ADS)

    Burton, S. P.; Ferrare, R. A.; Vaughan, M.; Hostetler, C. A.; Rogers, R. R.; Hair, J. W.; Cook, A. L.; Harper, D. B.

    2013-12-01

    Knowledge of aerosol type is important for source attribution and for determining the magnitude and assessing the consequences of aerosol radiative forcing. The NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL-1) has acquired considerable datasets of both aerosol extensive parameters (e.g. aerosol optical depth) and intensive parameters (e.g. aerosol depolarization ratio, lidar ratio) that can be used to infer aerosol type. An aerosol classification methodology has been used extensively to classify HSRL-1 aerosol measurements of different aerosol types including dust, smoke, urban pollution, and marine aerosol. However, atmospheric aerosol is frequently not a single pure type, but instead occurs as a mixture of types, and this mixing affects the optical and radiative properties of the aerosol. Here we present a comprehensive and unified set of rules for characterizing external mixtures using several key aerosol intensive parameters: extinction-to-backscatter ratio (i.e. lidar ratio), backscatter color ratio, and depolarization ratio. Our mixing rules apply not just to the scalar values of aerosol intensive parameters, but to multi-dimensional normal distributions with variance in each measurement dimension. We illustrate the applicability of the mixing rules using examples of HSRL-1 data where mixing occurred between different aerosol types, including advected Saharan dust mixed with the marine boundary layer in the Caribbean Sea and locally generated dust mixed with urban pollution in the Mexico City surroundings. For each of these cases we infer a time-height cross section of mixing ratio along the flight track and we partition aerosol extinction into portions attributed to the two pure types. Since multiple aerosol intensive parameters are measured and included in these calculations, the techniques can also be used for cases without significant depolarization (unlike similar work by earlier researchers), and so a third example of a

  16. 78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

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

  17. Particle Size Distribution of Airborne Microorganisms and Pathogens during an Intense African Dust Event in the Eastern Mediterranean

    PubMed Central

    Polymenakou, Paraskevi N.; Mandalakis, Manolis; Stephanou, Euripides G.; Tselepides, Anastasios

    2008-01-01

    Background The distribution of microorganisms, and especially pathogens, over airborne particles of different sizes has been ignored to a large extent, but it could have significant implications regarding the dispersion of these microorganisms across the planet, thus affecting human health. Objectives We examined the microbial quality of the aerosols over the eastern Mediterranean region during an African storm to determine the size distribution of microorganisms in the air. Methods We used a five-stage cascade impactor for bioaerosol collection in a coastal city on the eastern Mediterranean Sea during a north African dust storm. Bacterial communities associated with aerosol particles of six different size ranges were characterized following molecular culture–independent methods, regardless of the cell culturability (analysis of 16S rRNA genes). Results All 16S rDNA clone libraries were diverse, including sequences commonly found in soil and marine ecosystems. Spore-forming bacteria such as Firmicutes dominated large particle sizes (> 3.3 μm), whereas clones affiliated with Actinobacteria (found commonly in soil) and Bacteroidetes (widely distributed in the environment) gradually increased their abundance in aerosol particles of reduced size (< 3.3 μm). A large portion of the clones detected at respiratory particle sizes (< 3.3 μm) were phylogenetic neighbors to human pathogens that have been linked to several diseases. Conclusions The presence of aerosolized bacteria in small size particles may have significant implications to human health via intercontinental transportation of pathogens. PMID:18335093

  18. Tantalum dust deflagration in a bag filter dust-collecting device.

    PubMed

    Matsuda, T; Yamaguma, M

    2000-10-01

    An accidental tantalum powder deflagration with casualties occurred during the operation of a bag filter dust-collecting device. To understand the mechanism of the incident and its material hazards, experiments for determining the combustibility and ignition characteristics of the tantalum powder were performed. The magnitude of the tantalum dust explosion is classified as severe (K(st)=273), contrary to the classification found in the preceding literature. The minimum ignition energies for both a dust cloud and a dust layer of the tantalum powder were also found to be far lower than previous values. Judging from the observation of the surface with an SEM, the coral-like structure of each particle of the tantalum powder can enhance its fire and explosion hazards and affect its sensitivity to electrostatic sparks by increasing in particle surface area. A thin, non-conductive oxide layer of the tantalum powder surface has a high resistivity and generates electrostatic charge when rubbed with conductive materials like the wall of the collecting device. The authors conclude that the possible cause of the ignition was electrostatic discharge resulting from charging electrostatically. PMID:10946117

  19. Tantalum dust deflagration in a bag filter dust-collecting device.

    PubMed

    Matsuda, T; Yamaguma, M

    2000-10-01

    An accidental tantalum powder deflagration with casualties occurred during the operation of a bag filter dust-collecting device. To understand the mechanism of the incident and its material hazards, experiments for determining the combustibility and ignition characteristics of the tantalum powder were performed. The magnitude of the tantalum dust explosion is classified as severe (K(st)=273), contrary to the classification found in the preceding literature. The minimum ignition energies for both a dust cloud and a dust layer of the tantalum powder were also found to be far lower than previous values. Judging from the observation of the surface with an SEM, the coral-like structure of each particle of the tantalum powder can enhance its fire and explosion hazards and affect its sensitivity to electrostatic sparks by increasing in particle surface area. A thin, non-conductive oxide layer of the tantalum powder surface has a high resistivity and generates electrostatic charge when rubbed with conductive materials like the wall of the collecting device. The authors conclude that the possible cause of the ignition was electrostatic discharge resulting from charging electrostatically.

  20. The influence of coal physical and mechanical properties and mining energy consumption factor on airborne respirable dust level

    SciTech Connect

    Koziel, A.; Malec, M.; Wardas, E.

    1999-07-01

    The fact that there are not any explicitly defined relationships describing the influence of physical and mechanical properties of coal and of energy consumption factor on dust level prompted Polish and American investigators to carry out a joint research project within the framework of the US-Poland Maria Sklodowska-Curie Joint Fund II. The paper presents methods used to perform tests under laboratory conditions at the Pittsburgh Research Laboratory as well as under real conditions in the course of coal cutting in Polish coal mines. Measuring systems and results of the tests are described. The analysis carried out has provided a basis for determining the influence of specified operational parameters, i.e., coal compression strength R{sub c}, coal cuttability factor A, energy consumption factor of mining E{sub uc}, load of cutting drums as well as of laboratory parameters, i.e., grindability, coal breakage characteristics (product size distribution), moisture content, volatile and fixed carbon content, specific energy of crushing on a level of generated dust (total dust, specific dust and airborne respirable dust). The effect of technical parameters, i.e., face height, airflow velocity in a face, amount and pressure of water in spraying systems of longwall shearers, depth of cut taken by a cutting drum and application of powered cowls on dust level under operating conditions are also presented. Results of the tests made it possible to work out guidelines relating to methods and technology for effective reduction of dust emission on longwall faces.

  1. Airborne dust and aeroallergen concentration in a horse stable under two different management systems.

    PubMed

    Woods, P S; Robinson, N E; Swanson, M C; Reed, C E; Broadstone, R V; Derksen, F J

    1993-05-01

    Airborne dust concentration (ADC) was measured in 2 different horse management systems using an Andersen cascade impactor in the box-stall, and a personal Marple cascade impactor attached to the halter to measure ADC in the breathing zone. The levels of aeroallergens implicated in chronic obstructive pulmonary disease were measured by radioallergosorbent-inhibition immunoassay. A conventional management system (System C) utilising hay feed and straw bedding, and a recommended environment (System R) utilising wood shaving bedding and a complete pelleted diet were studied. In the stall, total and respirable ADC (geometric mean) were significantly higher in System C (2.55 mg/m3; 0.44 mg/m3, respectively) than in System R (0.70 mg/m3; 0.20 mg/m3, respectively). In System C, the total and respirable ADC in the breathing zone (17.51 mg/m3; 9.28 mg/m3) were much higher than in the stall, but values in both regions were similar in System R (0.52 mg/m3; 0.30 mg/m3). Major aeroallergens were significantly higher in System C than in System R: Micropolyspora faeni (1423 ng/m3 and 705 ng/m3), Aspergillus fumigatus (1823 ng/m3 and 748 ng/m3), and mite allergens (1420 ng/m3 and 761 ng/m3). Measurement of ADC with personal samplers indicates that the very high inhalation challenge in the breathing zone is not reflected in measurements of stall air quality. When compared with System C, System R produced only 3% of the respirable dust burden in the breathing zone and a decreased aeroallergen challenge.

  2. Total airborne mold particle sampling: evaluation of sample collection, preparation and counting procedures, and collection devices.

    PubMed

    Godish, Diana; Godish, Thad

    2008-02-01

    This study was conducted to evaluate (i) procedures used to collect, prepare, and count total airborne mold spore/particle concentrations, and (ii) the relative field performance of three commercially available total airborne mold spore/particle sampling devices. Differences between factory and laboratory airflow calibration values of axial fan-driven sampling instruments (used in the study) indicated a need for laboratory calibration using a mass flow meter to ensure that sample results were accurately calculated. An aniline blue-amended Calberla's solution adjusted to a pH of 4.2-4.4 provided good sample mounting/counting results using Dow Corning high vacuum grease, Dow Corning 280A adhesive, and Dow Corning 316 silicone release spray for samples collected using mini-Burkard and Allergenco samplers. Count variability among analysts was most pronounced in 5% counts of relatively low mold particle deposition density samples and trended downward with increased count percentage and particle deposition density. No significant differences were observed among means of 5, 10, and 20% counts and among analysts; a significant interaction effect was observed between analysts' counts and particle deposition densities. Significantly higher mini-Burkard and Air-O-Cell total mold spore/particle counts for 600x vs. 400x (1.9 and 2.3 x higher, respectively), 1000x vs. 600x (1.9 and 2.2 x higher, respectively) and 1000x vs. 400x (3.6 and 4.6 x higher, respectively) comparisons indicated that 1000x magnification counts best quantified total airborne mold spore/particles using light microscopy, and that lower magnification counts may result in unacceptable underreporting of airborne mold spore/particle concentrations. Modest but significantly higher (1.2x) total mold spore concentrations were observed with Allergenco vs. mini-Burkard samples collected in co-located, concurrently operated sampler studies; moderate but significantly higher mini-Burkard count values (1.4x) were

  3. Bioprocess of Kosa bioaerosols: effect of ultraviolet radiation on airborne bacteria within Kosa (Asian dust).

    PubMed

    Kobayashi, Fumihisa; Maki, Teruya; Kakikawa, Makiko; Yamada, Maromu; Puspitasari, Findya; Iwasaka, Yasunobu

    2015-05-01

    Kosa (Asian dust) is a well-known weather phenomenon in which aerosols are carried by the westerly winds from inland China to East Asia. Recently, the frequency of this phenomenon and the extent of damage caused have been increasing. The airborne bacteria within Kosa are called Kosa bioaerosols. Kosa bioaerosols have affected ecosystems, human health and agricultural productivity in downwind areas. In order to develop a new and useful bacterial source and to identify the source region of Kosa bioaerosols, sampling, isolation, identification, measurement of ultraviolet (UV) radiation tolerance and experimental simulation of UV radiation conditions were performed during Kosa bioaerosol transportation. We sampled these bioaerosols using a Cessna 404 airplane and a bioaerosol sampler at an altitude of approximately 2900 m over the Noto Peninsula on March 27, 2010. The bioaerosol particles were isolated and identified as Bacillus sp. BASZHR 1001. The results of the UV irradiation experiment showed that the UV radiation tolerance of Kosa bioaerosol bacteria was very high compared with that of a soil bacterium. Moreover, the UV radiation tolerance of Kosa bioaerosol spores was higher than that of soil bacterial spores. This suggested that Kosa bioaerosols are transported across the atmosphere as living spores. Similarly, by the experimental simulation of UV radiation conditions, the limited source region of this Kosa bioaerosol was found to be southern Russia and there was a possibility of transport from the Kosa source area. PMID:25735592

  4. Wind barriers suppress fugitive dust and soil-derived airborne particles in arid regions

    SciTech Connect

    Grantz, D.A.; Vaughn, D.L.; Farber, R.J.; Kim, B.; Ashbaugh, L.; Van Curen, T.; Campbell, R.

    1998-07-01

    Areas of abandoned agricultural land in the Antelope Valley, western Mojave (high) desert of California have proven in the previous studies to be recalcitrant to conventional tillage and revegetation strategies designed to suppress wind erosion of soil and transport of sediment and fugitive dust. These areas represented a continuing source of drifting sand and of coarse and respirable suspended particulate matter. The traditional techniques failed because furrows collapsed and the water holding capacity of the overburden was too low to support seed germination and transplant survival. In this study a variety of wind barriers were evaluated for suppression of sediment transport. Airborne particles were measured with an array of coarse particle samplers at heights of 0.2, 1.0, and 2.0 m above the soil surface. Discrete artificial wind barriers, consisting of widely spaced roughness elements were effective in suppressing fugitive emissions. Wind fences established along the leeward edge of an area of blowing sand, perpendicular to the prevailing wind, significantly decreased fugitive emissions. Control was greatest and precision of the measurements was highest under high wind conditions. These techniques provide rapid and effective suppression of fugitive emissions of soil-derived particles under conditions that resist conventional tillage and revegetation techniques. A simple, indirect procedure for determining local wind velocity erosion thresholds requiring only sampling of wind run and suspended particulate mass compared favorably with direct measurement of saltation as a function of wind velocity.

  5. Bioprocess of Kosa bioaerosols: effect of ultraviolet radiation on airborne bacteria within Kosa (Asian dust).

    PubMed

    Kobayashi, Fumihisa; Maki, Teruya; Kakikawa, Makiko; Yamada, Maromu; Puspitasari, Findya; Iwasaka, Yasunobu

    2015-05-01

    Kosa (Asian dust) is a well-known weather phenomenon in which aerosols are carried by the westerly winds from inland China to East Asia. Recently, the frequency of this phenomenon and the extent of damage caused have been increasing. The airborne bacteria within Kosa are called Kosa bioaerosols. Kosa bioaerosols have affected ecosystems, human health and agricultural productivity in downwind areas. In order to develop a new and useful bacterial source and to identify the source region of Kosa bioaerosols, sampling, isolation, identification, measurement of ultraviolet (UV) radiation tolerance and experimental simulation of UV radiation conditions were performed during Kosa bioaerosol transportation. We sampled these bioaerosols using a Cessna 404 airplane and a bioaerosol sampler at an altitude of approximately 2900 m over the Noto Peninsula on March 27, 2010. The bioaerosol particles were isolated and identified as Bacillus sp. BASZHR 1001. The results of the UV irradiation experiment showed that the UV radiation tolerance of Kosa bioaerosol bacteria was very high compared with that of a soil bacterium. Moreover, the UV radiation tolerance of Kosa bioaerosol spores was higher than that of soil bacterial spores. This suggested that Kosa bioaerosols are transported across the atmosphere as living spores. Similarly, by the experimental simulation of UV radiation conditions, the limited source region of this Kosa bioaerosol was found to be southern Russia and there was a possibility of transport from the Kosa source area.

  6. Optimization of the concentration optics of the Martian airborne dust sensor for MetNet space mission

    NASA Astrophysics Data System (ADS)

    Cortés, F.; González, A.; de Castro, A. J.; López, F.

    2012-06-01

    Martian atmosphere contains a significant and rapidly changing load of suspended dust that never drops to zero. The main component of Martian aerosol is micron-sized dust thought to be a product of soil weathering. Although airborne dust plays a key role in Martian climate, the basic physical properties of these aerosols are still poorly known. The scope of Mars MetNet Mission is to deploy several tens of mini atmospheric stations on the Martian surface. MEIGA-MetNet payload is the Spanish contribution in MetNet. Infrared Laboratory of University Carlos III (LIR-UC3M) is in charge of the design and development of a micro-sensor for the characterization of airborne dust. This design must accomplish with a strict budget of mass and power, 45 g and 1 W respectively. The sensor design criteria have been obtained from a physical model specifically developed for optimizing IR local scattering. The model calculates the spectral power density scattered and detected between 1 and 5 μm by a certain particle distribution and sensor configuration. From model calculations a modification based on the insertion of a compound ellipsoidal concentrator (CEC) has appeared as necessary. Its implementation has multiplied up to 100 the scattered optical power detected, significantly enhancing the detection limits of the sensor.

  7. Abundance and Community Structure of Bacteria on Asian Dust Particles Collected in Beijing, China, during the Asian Dust Season.

    PubMed

    Yamaguchi, Nobuyasu; Baba, Takashi; Ichijo, Tomoaki; Himezawa, Yuka; Enoki, Kanami; Saraya, Makoto; Li, Pin-Fang; Nasu, Masao

    2016-01-01

    Approximately 180 t/km(2) of Asian dust particles are estimated to fall annually on Beijing, China, and there is significant concern about the influence of microbes transported by Asian dust events on human health and downwind ecosystems. In this study, we collected Asian dust particles in Beijing, and analyzed the bacterial communities on these particles by culture-independent methods. Bacterial cells on Asian dust particles were visualized first by laser scanning microscopy, which demonstrated that Asian dust particles carry bacterial cells to Beijing. Bacterial abundance, as determined by quantitative polymerase chain reaction (PCR), was 10(8) to 10(9) cells/g, a value about 10 times higher than that in Asian dust source soils. Inter-seasonal variability of bacterial community structures among Asian dust samples, as compared by terminal restriction fragment length polymorphism (T-RFLP), was low during the Asian dust season. Several viable bacteria, including intestinal bacteria, were found in Asian dust samples by denaturing gradient gel electrophoresis (DGGE). Clone library analysis targeting 16S ribosomal RNA (rRNA) gene sequences demonstrated that bacterial phylogenetic diversity was high in the dust samples, and most of these were environmental bacteria distributed in soil and air. The dominant species in the clone library was Segetibacter aerophilus (Bacteroidetes), which was first isolated from an Asian dust sample collected in Korea. Our results also indicate the possibility of a change in the bacterial community structure during transportation and increases in desiccation-tolerant bacteria such as Firmicutes.

  8. Recognizing Leonid Meteoroids Among The Collected Startospheric Dust

    NASA Technical Reports Server (NTRS)

    Rietmeijer, Frans J. M.; Jenniskens, Peter; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Three chemical groups of primary "silicate" spheres <30 micron in diameter of cometary origin were collected in the lower stratosphere between 1981 May and 1994 July. The "silicate" sphere abundances represent an annual background from contributions by sporadic meteor and weak annual meteor shower activities. During two collection periods, from 06/22 until 08/18, 1983 (U2015), and from 09/15-12/15, 1981 (W7027/7029), a higher number of spheres was collected compared to other periods of the year represented by the other collectors studied here. This study links two different data sets, viz. the NASA/JSC Cosmic Dust Catalogs and peak activities of annual meteor showers, and identified high-velocity cometary sources for collected stratospheric "silicate" spheres. The majority of spheres on flag U2015 may originate from comet P/Swift-Tuttle (Perseids), while the majority of spheres on flags W7027/7029 could be from comet P/Halley (Orionids) or comet P/Tempel-Tuttle (Leonids). Variations in relative proportions of the Mg,Si,Ca +/- Al, Mg,Si +/- Fe and Al,Si,Ca spheres may offer a hint of chemical differences among high-velocity comets. Proof for the findings reported here might be obtained by targeted cosmic dust collections in the lower stratosphere including periods of meteor shower and storm activity.

  9. Recognizing Leonid Meteoroids among the Collected Stratospheric Dust

    NASA Astrophysics Data System (ADS)

    Rietmeijer, Frans J. M.; Jenniskens, Peter

    Three chemical groups of primary "silicate" spheres <30 µm in diameter of cometary origin were collected in the lower stratosphere between 1981 May and 1994 July. The "silicate" sphere abundances represent an annual background from contributions by sporadic meteor and weak annual meteor shower activities. During two collection periods, from 06/22 until 08/18, 1983 (U2015), and from 09/15-12/15, 1981 (W7027/7029), a higher number of spheres was collected compared to other periods of the year represented by the other collectors studied here. This study links two different data sets, viz. the NASSA/JSC Cosmic Dust Catalogs and peak activities of annual meteor showers, and identified high-velocity cometary sources for collected stratospheric "silicate" spheres. The majority of spheres on flag U2015 may originate from comet P/Swift-Tuttle (Perseids), while the majority of spheres on flags W7027/7029 could be from comet P/Halley (Orionids) or comet P/Tempel-Tuttle (Leonids). Variations in relative proportions of the Mg,Si,Ca +/- Al, Mg,Si +/- Fe and Al, Si,Ca spheres may offer a hint of chemical differences among high-velocity comets. Proof for the findings reported here might be obtained by targeted cosmic dust collections in the lower stratosphere including periods of meteor shower and storm activity.

  10. Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

    NASA Astrophysics Data System (ADS)

    Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

    2010-05-01

    For the interpretation of airborne gamma-ray spectrometry as well as airborne electromagnetics it is of great importance to determine the distance between the geophysical sensor and the ground surface. Since radar altimeters do not penetrate vegetation, laser altimeters became popular in airborne geophysics over the past years. Currently the airborne geophysical platform of the Geological Survey of Austria (GBA) is equipped with a Riegl LD90-3800VHS-FLP high resolution laser altimeter, measuring the distances according to the first and the last reflected pulse. The goal of the presented study was to explore the possibilities of deriving additional information about the survey area from the laser data and to determine the accuracy of such results. On one hand the difference between the arrival time of the first and the last reflected pulse can be used to determine the height of the vegetation. This parameter is for example important for the correction of damping effects on airborne gamma-ray measurements caused by vegetation. Moreover especially for groundwater studies at catchment scale, this parameter can also be applied to support the spatial assessment of evapotranspiration. In combination with the altitude above geoid, determined by a GPS receiver, a rough digital elevation model of the survey area can be derived from the laser altimetry. Based on a data set from a survey area in the northern part of Austria, close to the border with the Czech Republic, the reliability of such a digital elevation model and the calculated vegetation height was tested. In this study a mean deviation of -1.4m, with a standard deviation of ±3.4m, between the digital elevation model from Upper Austria (25m spatial resolution) and the determined elevation model was determined. We also found an obvious correlation between the calculated vegetation heights greater 15m and the mapped forest published by the ‘Department of Forest Inventory' of the ‘Federal Forest Office' of Austria

  11. An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Saharan Dust During the NAMMA Field Campaign

    NASA Technical Reports Server (NTRS)

    Hansell, R. A.; Tsay, S. C.; Ji, Q.; Hsu, N. C.; Jeong, M. J.; Wang, S. H.; Reid, J. S.; Liou, K. N.; Ou, S. C.

    2010-01-01

    In September 2006, NASA Goddard s mobile ground-based laboratories were deployed to Sal Island in Cape Verde (16.73degN, 22.93degW) to support the NASA African Monsoon Multidisciplinary Analysis (NAMMA) field study. The Atmospheric Emitted Radiance Interferometer (AERI), a key instrument for spectrally characterizing the thermal IR, was used to retrieve the dust IR aerosol optical depths (AOTs) in order to examine the diurnal variability of airborne dust with emphasis on three separate dust events. AERI retrievals of dust AOT are compared with those from the coincident/collocated multifilter rotating shadow-band radiometer (MFRSR), micropulse lidar (MPL), and NASA Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) sensors. The retrieved AOTs are then inputted into the Fu-Liou 1D radiative transfer model to evaluate local instantaneous direct longwave radiative effects (DRE(sub LW)) of dust at the surface in cloud-free atmospheres and its sensitivity to dust microphysical parameters. The top-of-atmosphere DRE(sub LW) and longwave heating rate profiles are also evaluated. Instantaneous surface DRE(sub LW) ranges from 2 to 10 W/sq m and exhibits a strong linear dependence with dust AOT yielding a DRE(sub LW) of 16 W/sq m per unit dust AOT. The DRE(sub LW) is estimated to be approx.42% of the diurnally averaged direct shortwave radiative effect at the surface but of opposite sign, partly compensating for the shortwave losses. Certainly nonnegligible, the authors conclude that DRE(sub LW) can significantly impact the atmospheric energetics, representing an important component in the study of regional climate variation.

  12. Elevated Airborne Exposures of Teenagers to Manganese, Chromium, and Iron from Steel Dust and New York City’s Subway System

    PubMed Central

    CHILLRUD, STEVEN N.; EPSTEIN, DAVID; ROSS, JAMES M.; SAX, SONJA N.; PEDERSON, DEE; SPENGLER, JOHN D.; KINNEY, PATRICK L.

    2011-01-01

    There is increasing interest in potential health effects of airborne exposures to hazardous air pollutants at relatively low levels. This study focuses on sources, levels, and exposure pathways of manganese, chromium, and iron among inner-city high school students in New York City (NYC) and the contribution of subways. Samples of fine particulate matter (PM2.5) were collected during winter and summer over 48 h periods in a variety of settings including inside homes, outdoors, and personal samples (i.e., sampling packs carried by subjects). PM2.5 samples were also collected in the NYC subway system. For NYC, personal samples had significantly higher concentrations of iron, manganese, and chromium than did home indoor and ambient samples. The ratios and strong correlations between pairs of elements suggested steel dust as the source of these metals for a large subset of the personal samples. Time–activity data suggested NYC subways as a likely source of these elevated personal metals. In duplicate PM2.5 samples that integrated 8 h of underground subway exposure, iron, manganese, and chromium levels (>2 orders of magnitude above ambient levels) and their ratios were consistent with the elevated personal exposures. Steel dust in the NYC subway system was the dominant source of airborne exposures to iron, manganese, and chromium for many young people enrolled in this study, with the same results expected for other NYC subway riders who do not have occupational exposures to these metals. However, there are currently no known health effects at the exposure levels observed in this study. PMID:14968857

  13. Natural Airborne Dust and Heavy Metals: A Case Study for Kermanshah, Western Iran (2005–2011)

    PubMed Central

    PIRSAHEB, Meghdad; ZINATIZADEH, Aliakbar; KHOSRAVI, Touba; ATAFAR, Zahra; DEZFULINEZHAD, Saeed

    2014-01-01

    Abstract Background Dust pollution has become a serious environmental problem especially in recent decades. The present study aim was the investigation of the levels of PM10 concentration in Kermanshah, western Iran and also measured five important heavy metals (Pb, Cd, As, Hg and Cr) in some samples during 2005 to 2011. Methods A total 2277 samples were collected from air pollution measurement station belonging to the Department of Environment in Kermanshah. Furthermore, four samples were collected during dusty days to determine the selected heavy metals concentration. The samples were analyzed statistically using the SPSS Ver.16 Results The highest seasonal average concentration in spring was recorded in 2008 with 216.63μg/m3, and the maximum values of 267.79 and 249.09μg/m3 were observed in summer and winter in 2009, respectively. The maximum concentration of 127.1μg/m3 was in autumn in 2010. The metals concentration (Pb, Cd, As, Hg and Cr) of samples were 42.32±5.40, 37.45±9.29, 3.51±2.07, 1.88±1.64 and 0μg/g in July, 2009, respectively. Conclusion According to National Ambient Air Quality of USEPA guidelines, the most days with non-standard, warning, emergency and critical conditions were related to 2009 (120 days) while the least polluted days were recorded in 2006 (16 days). There are concerns about the increasing frequency and intensity trend of dust storms in recent years as a result of special condition in neighboring Western countries which it could endanger public health and environment. All measured heavy metals except mercury was higher than the standard level of WHO and USEPA. PMID:26005656

  14. Multisensor airborne imagery collection and processing onboard small unmanned systems

    NASA Astrophysics Data System (ADS)

    Linne von Berg, Dale; Anderson, Scott A.; Bird, Alan; Holt, Niel; Kruer, Melvin; Walls, Thomas J.; Wilson, Michael L.

    2010-04-01

    FEATHAR (Fusion, Exploitation, Algorithms, and Targeting for High-Altitude Reconnaissance) is an ONR funded effort to develop and test new tactical sensor systems specifically designed for small manned and unmanned platforms (payload weight < 50 lbs). This program is being directed and executed by the Naval Research Laboratory (NRL) in conjunction with the Space Dynamics Laboratory (SDL). FEATHAR has developed and integrated EyePod, a combined long-wave infrared (LWIR) and visible to near infrared (VNIR) optical survey & inspection system, with NuSAR, a combined dual band synthetic aperture radar (SAR) system. These sensors are being tested in conjunction with other ground and airborne sensor systems to demonstrate intelligent real-time cross-sensor cueing and in-air data fusion. Results from test flights of the EyePod and NuSAR sensors will be presented.

  15. 30 CFR 33.9 - Certification of dust-collecting systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL... numbers of the dust-collector parts, and description of the limitations for which performance is certified... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Certification of dust-collecting systems....

  16. Cometary dust: A thermal criterion to identify cometary samples among the collected interplanetary dust

    NASA Astrophysics Data System (ADS)

    Flynn, George J.

    The relative proportions of the cometary and the asteroidal contributions to the interplanetary dust have not yet been definitively established. These proportions may vary with time as a result of major catastrophic disruptions in the main belt or the appearance of fresh, active comets. Dermott et al. and Reach suggest the debris from catastrophic collisions in the main belt can account for most of the zodiacal cloud particles. Earth collection of these asteroidal particles is strongly favored by near-Earth gravitational enhancement. However, comets are observed to produce interplanetary dust particles (IDP's), and the identification of cometary IDP's would allow inferences of the compositions, mineralogies, and physical properties of the comets. The peak temperatures reached by IDP's on atmospheric entry indicate the distribution of IDP velocities. Each IDP contains many internal thermometers: minerals that transform above certain temperatures, volatile elements that are lost sequentially with increasing temperatures, solar flare tracks that anneal at different temperatures in different minerals, and solar-implanted noble gases that outgas progressively with temperature. Thus, limits on the peak temperature reached by each IDP on Earth atmospheric entry can be set. Other aspects of this investigation are covered.

  17. Cometary dust: A thermal criterion to identify cometary samples among the collected interplanetary dust

    NASA Technical Reports Server (NTRS)

    Flynn, George J.

    1994-01-01

    The relative proportions of the cometary and the asteroidal contributions to the interplanetary dust have not yet been definitively established. These proportions may vary with time as a result of major catastrophic disruptions in the main belt or the appearance of fresh, active comets. Dermott et al. and Reach suggest the debris from catastrophic collisions in the main belt can account for most of the zodiacal cloud particles. Earth collection of these asteroidal particles is strongly favored by near-Earth gravitational enhancement. However, comets are observed to produce interplanetary dust particles (IDP's), and the identification of cometary IDP's would allow inferences of the compositions, mineralogies, and physical properties of the comets. The peak temperatures reached by IDP's on atmospheric entry indicate the distribution of IDP velocities. Each IDP contains many internal thermometers: minerals that transform above certain temperatures, volatile elements that are lost sequentially with increasing temperatures, solar flare tracks that anneal at different temperatures in different minerals, and solar-implanted noble gases that outgas progressively with temperature. Thus, limits on the peak temperature reached by each IDP on Earth atmospheric entry can be set. Other aspects of this investigation are covered.

  18. Variations in the structure of airborne bacterial communities in a downwind area during an Asian dust (Kosa) event.

    PubMed

    Maki, Teruya; Puspitasari, Findya; Hara, Kazutaka; Yamada, Maromu; Kobayashi, Fumihisa; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2014-08-01

    Asian dust (Kosa) events transport airborne microorganisms that significantly impact biological ecosystems, human health, and ice-cloud formation in downwind areas. However, the composition and population dynamics of airborne bacteria have rarely been investigated in downwind areas during Kosa events. In this study, air samplings were sequentially performed at the top of a 10-m high building within the Kosa event arrival area (Kanazawa City, Japan) from May 1 to May 7, 2011, during a Kosa event. The particle concentrations of bacterial cells and mineral particles were ten-fold higher during the Kosa event than on non-Kosa event days. A 16S ribosomal DNA clone library prepared from the air samples primarily contained sequences from three phyla: Cyanobacteria, Firmicutes, and Alphaproteobacteria. The clones from Cyanobacteria were mainly from a marine type of Synechococcus species that was dominant during the first phase of the Kosa event and was continuously detected throughout the Kosa event. The clones from Alphaproteobacteria were mainly detected at the initial and final periods of the Kosa event, and phylogenetic analysis showed that their sequences clustered with those from a marine bacterial clade (the SAR clade) and Sphingomonas spp. During the middle of the Kosa event, the Firmicutes species Bacillus subtilis and Bacillus pumilus were predominant; these species are known to be predominant in the atmosphere above the Chinese desert, which is the source of the dust during Kosa events. The clones obtained after the Kosa event had finished were mainly from Bacillus megaterium, which is thought to originate from local terrestrial areas. Our results suggest that airborne bacterial communities at the ground level in areas affected by Kosa events change their species compositions during a Kosa event toward those containing terrestrial and pelagic bacteria transported from the Sea of Japan and the continental area of China by the Kosa event. PMID:24815557

  19. Saharan dust long-range transport across the Atlantic studied by an airborne Doppler wind lidar and the MACC model

    NASA Astrophysics Data System (ADS)

    Chouza, Fernando; Reitebuch, Oliver; Benedetti, Angela; Weinzierl, Bernadett

    2016-09-01

    A huge amount of dust is transported every year from north Africa into the Caribbean region. This paper presents an investigation of this long-range transport process based on airborne Doppler wind lidar (DWL) measurements conducted during the SALTRACE campaign (June-July 2013), as well as an evaluation of the ability of the MACC (Monitoring Atmospheric Composition and Climate) global aerosol model to reproduce it and its associated features. Although both the modeled winds from MACC and the measurements from the DWL show a generally good agreement, some differences, particularly in the African easterly jet (AEJ) intensity, were noted. The observed differences between modeled and measured wind jet speeds are between 5 and 10 m s-1. The vertical aerosol distribution within the Saharan dust plume and the marine boundary layer is investigated during the June-July 2013 period based on the MACC aerosol model results and the CALIOP satellite lidar measurements. While the modeled Saharan dust plume extent shows a good agreement with the measurements, a systematic underestimation of the marine boundary layer extinction is observed. Additionally, three selected case studies covering different aspects of the Saharan dust long-range transport along the west African coast, over the North Atlantic Ocean and the Caribbean are presented. For the first time, DWL measurements are used to investigate the Saharan dust long-range transport. Simultaneous wind and backscatter measurements from the DWL are used, in combination with the MACC model, to analyze different features associated with the long-range transport, including an African easterly wave trough, the AEJ and the intertropical convergence zone.

  20. 78 FR 44625 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

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

  1. Airborne Fungi in Sahara Dust Aerosols Reaching the Eastern Caribbean: II. Species Identification Using Molecular Techniques

    NASA Astrophysics Data System (ADS)

    de La Mota, A.; Betancourt, C.; Detres, Y.; Armstrong, R.

    2003-12-01

    Fungi samples from filters collected in Castle Bruce, Dominica from March through July 2002, were previously purified and identified to genus level using classic macroscopic and microscopic techniques. A total of 105 isolated colonies were cultured in liquid media and the mycelial mats used for DNA extraction. PCR was used to amplify the ITS region of the rDNA using the ITS1 and ITS4 primers. Both strands of the amplified products were sequenced and the final identification to species level was completed by a GenBank search. Fourteen different species and one fungal endophyte were identified from genders Aspergillus,Penicillium, Fusarium, Cladosporium, Curvularia and Phanerochaete. Some of these species such as A. fumigatus, A. japonicus, P. citrinum and C. cladosporoides are known to cause respiratory disorders in humans. A. fumigatus causes an aggressive pulmonary allergic response that might result in allergic bronchopulmonary aspergillosis. Other species such as F. equiseti and C. brachyspora are plant pathogens affecting economically important crops. Sahara dust is an important source of fungal spores of species that are not common in the Caribbean region.

  2. Airborne Fungi in Sahara Dust Aerosols Reaching the Eastern Caribbean: I. Taxonomic Characterization by Morphological Features

    NASA Astrophysics Data System (ADS)

    Rivera-Denizard, O.; Betancourt, C.; Armstrong, R. A.; Detres, Y.

    2003-12-01

    A wide variety of microorganisms are dispersed into the Caribbean region due to the input of Saharan dust aerosols during the summer months. These microorganisms can cause diseases in plants and animals, and might be responsible for an increase incidence of asthma and respiratory diseases in this region. A PM 2.5 air sampling station was installed in Castle Bruce, Dominica from March through July of 2002. Fourteen filters were obtained by running the air sampler continuously for 24 hour periods. The samples were collected in sterile Teflon filters (47 mm in diameter, 0.2 um pore size), inoculated in Malt Extract Agar (MEA) with lactic acid and incubated at 29° C. Colonies were counted, isolated and cultured on separate Petri dishes. Fungal classification to the genus level used macroscopic features and microscopic evaluation. The Nomarski light microscopy technique was used for identification of reproductive structures. A total of 105 colonies were isolated. Six genera including Aspergillus, Penicillium, Cladosporium, Fusarium, Curvularia,and Nigrospora were identified. The protocol for the molecular characterization to species level is presented as the second part of this work.

  3. Dust collection efficiency analysis in a two-dimensional circulating granular bed filter.

    PubMed

    Bai, Jing-Cheng; Wu, Shu-Yii; Lee, An-Sheng

    2006-05-01

    Dust collection efficiency data were analyzed to determine better operating conditions for a two-dimensional circulating granular bed filter (CGBF). The dust collection efficiency in the granular bed was affected by the following operating parameters: the louver angle, the solids mass flow rate, and the particle size of the bed material. Experimental results showed that higher dust collection efficiency occurs when the solids mass flow rates were 20.34 +/- 0.24, 21.50 +/- 0.11, and 30.51 +/- 0.57 g/sec at louver angles of 45 degrees, 30 degrees, and 20 degrees, respectively. Optimal dust collection efficiency peaked with a louver angle of 30 degrees. Average particle sizes of bed material by sieve diameters (microm) of 795 microm had higher dust collection efficiency than the average collector particle size of 1500 microm. Dust collection efficiency is influenced by bed material attrition phenomenon, causing dust collection efficiency to decrease rapidly. The dust collection efficiency analysis not only found the system free of design defects but also assisted in the operation of the two-dimensional CGBF system.

  4. Interstellar dust. Evidence for interstellar origin of seven dust particles collected by the Stardust spacecraft.

    PubMed

    Westphal, Andrew J; Stroud, Rhonda M; Bechtel, Hans A; Brenker, Frank E; Butterworth, Anna L; Flynn, George J; Frank, David R; Gainsforth, Zack; Hillier, Jon K; Postberg, Frank; Simionovici, Alexandre S; Sterken, Veerle J; Nittler, Larry R; Allen, Carlton; Anderson, David; Ansari, Asna; Bajt, Saša; Bastien, Ron K; Bassim, Nabil; Bridges, John; Brownlee, Donald E; Burchell, Mark; Burghammer, Manfred; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M; Doll, Ryan; Floss, Christine; Grün, Eberhard; Heck, Philipp R; Hoppe, Peter; Hudson, Bruce; Huth, Joachim; Kearsley, Anton; King, Ashley J; Lai, Barry; Leitner, Jan; Lemelle, Laurence; Leonard, Ariel; Leroux, Hugues; Lettieri, Robert; Marchant, William; Ogliore, Ryan; Ong, Wei Jia; Price, Mark C; Sandford, Scott A; Sans Tresseras, Juan-Angel; Schmitz, Sylvia; Schoonjans, Tom; Schreiber, Kate; Silversmit, Geert; Solé, Vicente A; Srama, Ralf; Stadermann, Frank; Stephan, Thomas; Stodolna, Julien; Sutton, Stephen; Trieloff, Mario; Tsou, Peter; Tyliszczak, Tolek; Vekemans, Bart; Vincze, Laszlo; Von Korff, Joshua; Wordsworth, Naomi; Zevin, Daniel; Zolensky, Michael E

    2014-08-15

    Seven particles captured by the Stardust Interstellar Dust Collector and returned to Earth for laboratory analysis have features consistent with an origin in the contemporary interstellar dust stream. More than 50 spacecraft debris particles were also identified. The interstellar dust candidates are readily distinguished from debris impacts on the basis of elemental composition and/or impact trajectory. The seven candidate interstellar particles are diverse in elemental composition, crystal structure, and size. The presence of crystalline grains and multiple iron-bearing phases, including sulfide, in some particles indicates that individual interstellar particles diverge from any one representative model of interstellar dust inferred from astronomical observations and theory.

  5. Comparison of filter bag, cyclonic, and wet dust collection methods in vacuum cleaners.

    PubMed

    Trakumas, S; Willeke, K; Reponen, T; Grinshpun, S A; Friedman, W

    2001-01-01

    In this study, methods were developed for comparative evaluation of three primary dust collection methods employed in vacuum cleaners: filter bag, cyclonic, and wet primary dust collection. The dry collectors were evaluated with KCl test aerosols that are commonly used in filter testing. However, these aerosols cannot be used for evaluating wet collectors due to their hygroscopicity. Therefore, the wet collectors were evaluated with nonhygroscopic test particles. Both types of test aerosol indicated similar collection efficiencies in tests with dry collectors. The data show that high initial collection efficiency can be achieved by any one of the three dust collection methods: up to 50% for 0.35 microm particles, and close to 100% for 1.0 microm and larger particles. The degree of dependence of the initial collection efficiency on airflow rate was strongly related to the type and manufacturing of the primary dust collector. Collection efficiency decreased most with decreasing flow rate for the tested wet collectors. The tested cyclonic and wet collectors showed high reentrainment of already collected dust particles. After the filter bag collectors had been loaded with test dust, they also reemitted particles. The degree of reentrainment from filter bags depends on the particulate load and the type of filter material used. Thus, the overall particle emissions performance of a vacuum cleaner depends not only on the dust collection efficiency of the primary collector and other filtration elements employed, but also on the degree of reentrainment of already collected particles.

  6. Apparatus for collection of dust and soot by wetting

    SciTech Connect

    Kovac, E.

    1984-06-05

    A dust and soot collector surrounds a top portion of a stack or duct. Sprays of water are directed across a path of a gas flow exiting the stack. The water removes particles of dust and soot from the gas. A slush is created which falls into a peripheral trough and is removed.

  7. The simulation of cosmic dust collection process with little damage

    NASA Astrophysics Data System (ADS)

    Li, Danming; Li, Yali; Wu, Qingxiao; Dai, Peng

    2016-07-01

    To built a cosmic dust collector according to a predetermined concept, mateirals that can be used to buffer the poential high speed collision of the cosmic dust have been studied. In this study, aerogel was chosen as an ideal buffer material and analyzed with SPH modeling method which is embedded in ABAQUS FE code. This report presents the interactions of cosmic dust, varing composition, shape and velocity, with the buffer material. The results show that cosmic dust that moves at 6 Km/s or less can be captured with minor damage to the buffer material of certain length. The simulation provides favorable technical support for the structural design of the cosmic dust collector.

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

    PubMed

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

    2002-11-01

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

  9. Airborne particles in Swansea, UK: their collection and characterization.

    PubMed

    Price, Heather; Arthur, Robert; Sexton, Keith; Gregory, Clive; Hoogendoorn, Bastiaan; Matthews, Ian; Jones, Tim; BéruBé, Kelly

    2010-01-01

    Urban air particulate matter (PM) has previously been associated with a variety of adverse health effects. It is now believed that the smallest particles, ultrafine or nanoparticles, are linked to the greatest health effects. The physicochemistry of these particles is likely to provide information regarding their toxicity. Therefore, the aim of this study was to further the understanding of the heterogeneous and changing particle concentrations in urban air, in conjunction with gaining an understanding of the physicochemistry of the particles. A Dekati electrical low-pressure impactor was used to collect the particles and real-time data in a busy traffic corridor in Swansea, Wales, over a period of 10 nonconsecutive weeks. Particle concentrations in the street canyon were analyzed and particle physicochemistries investigated using a variety of techniques. Particle number concentrations were found to vary both diurnally and from day to day in the traffic corridor. Of all particles, the nano to fine size fraction was consistently identified in the highest concentrations (maximum: 140,000 particles cm(-3)). Particle physicochemistry was found to vary as a function of size, with larger particles exhibiting a greater variety of morphologies (and consequently particle types) and associated metals. PMID:20155578

  10. Apparatus for real-time airborne particulate radionuclide collection and analysis

    DOEpatents

    Smart, John E.; Perkins, Richard W.

    2001-01-01

    An improved apparatus for collecting and analyzing an airborne particulate radionuclide having a filter mounted in a housing, the housing having an air inlet upstream of the filter and an air outlet downstream of the filter, wherein an air stream flows therethrough. The air inlet receives the air stream, the filter collects the airborne particulate radionuclide and permits a filtered air stream to pass through the air outlet. The improvement which permits real time counting is a gamma detecting germanium diode mounted downstream of the filter in the filtered air stream. The gamma detecting germanium diode is spaced apart from a downstream side of the filter a minimum distance for a substantially maximum counting detection while permitting substantially free air flow through the filter and uniform particulate radionuclide deposition on the filter.

  11. Passive airborne dust sampling with the electrostatic dustfall collector: optimization of storage and extraction procedures for endotoxin and glucan measurement.

    PubMed

    Noss, Ilka; Doekes, Gert; Sander, Ingrid; Heederik, Dick J J; Thorne, Peter S; Wouters, Inge M

    2010-08-01

    We recently introduced a passive dust sampling method for airborne endotoxin and glucan exposure assessment-the electrostatic dustfall collector (EDC). In this study, we assessed the effects of different storage and extraction procedures on measured endotoxin and glucan levels, using 12 parallel EDC samples from 10 low exposed indoor environments. Additionally, we compared 2- and 4-week sampling with the prospect of reaching higher dust yields. Endotoxin concentrations were highest after extraction with pyrogen-free water (pf water) + Tween. Phosphate-buffered saline (PBS)-Tween yielded significantly (44%) lower levels, and practically no endotoxin was detected after extraction in pf water without Tween. Glucan levels were highest after extraction in PBS-Tween at 120 degrees C, whereas extracts made in NaOH at room temperature or 120 degrees C were completely negative. Direct extraction from the EDC cloth or sequential extraction after a preceding endotoxin extraction yielded comparable glucan levels. Sample storage at different temperatures before extraction did not affect endotoxin and glucan concentrations. Doubling the sampling duration yielded similar endotoxin and only 50% higher glucan levels. In conclusion, of the tested variables, the extraction medium was the predominant factor affecting endotoxin and glucan yields.

  12. Monitoring airborne dust in a high density coal-fired power station region in North Yorkshire.

    PubMed

    Vallack, H W; Chadwick, M J

    1993-01-01

    Concerns about the levels of dust deposition in the vicinity of coal-fired power stations in North Yorkshire, in particular Drax Power Station, prompted the commissioning of a detailed monitoring study in the area. This paper describes the first two years' work. The first 12-month study concentrated on the village of Barlow close to Drax Power Station, whilst in the second 12-month study, monitoring sites were spread along a transect passing through the power station belt formed by Ferrybridge, Eggborough and Drax Power Stations. Two monitoring sites were common to both 12-month studies, thus giving two years of continuous monitoring. Pairs of wet Frisbee dust deposit gauges (based on inverted Frisbees) were located at each site. Undissolved particulate matter from each gauge was weighed and characterized by microscopic examination of individual particles. The first 12-month study revealed a downward gradient in dust deposition rate and cenosphere content with distance from Drax Power Station. The high cenosphere content at Barlow, especially at the eastern end, suggested that there was a significant contribution from coal-fired power stations. In the second year, the overall pattern of dust deposition rate and cenosphere content across the power station belt suggested that power stations were contributing to higher levels. In particular, relatively high levels were again found at Barlow. Wind direction correlations point to the fly-ash tip next to Drax Power Station as being the source of cenospheres arriving at Barlow. It is concluded that in both years the fly-ash tip Drax Power Station was making a significant contribution to higher than expected dust deposition rates at Barlow, particularly its eastern end. Other villages in the area may also have been affected by dust originating from coal-fired power stations.

  13. Respiratory protection provided by N95 filtering facepiece respirators against airborne dust and microorganisms in agricultural farms.

    PubMed

    Lee, Shu-An; Adhikari, Atin; Grinshpun, Sergey A; McKay, Roy; Shukla, Rakesh; Zeigler, Haoyue Li; Reponen, Tiina

    2005-11-01

    A new system was used to determine the workplace protection factors (WPF) for dust and bioaerosols in agricultural environments. The field study was performed with a subject wearing an N95 filtering facepiece respirator while performing animal feeding, grain harvesting and unloading, and routine investigation of facilities. As expected, the geometric means (GM) of the WPFs increased with increasing particle size ranging from 21 for 0.7-1 microm particles to 270 for 5-10 microm particles (p < 0.001). The WPF for total culturable fungi (GM = 35) was significantly greater than for total culturable bacteria (GM = 9) (p = 0.01). Among the different microorganism groups, the WPFs of Cladosporium, culturable fungi, and total fungi were significantly correlated with the WPFs of particles of the same sizes. As compared with the WPFs for dust particles, the WPFs for bioaerosols were found more frequently below 10, which is a recommended assigned protection factor (APF) for N95 filtering facepiece respirators. More than 50% of the WPFs for microorganisms (mean aerodynamic diameter < 5 microm) were less than the proposed APF of 10. Even lower WPFs were calculated after correcting for dead space and lung deposition. Thus, the APF of 10 for N95 filtering facepiece respirators seems inadequate against microorganisms (mean aerodynamic size < 5 microm). These results provide useful pilot data to establish guidelines for respiratory protection against airborne dust and microorganisms on agricultural farms. The method is a promising tool for further epidemiological and intervention studies in agricultural and other similar occupational and nonoccupational environments. PMID:16234218

  14. 30 CFR 33.9 - Certification of dust-collecting systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Certification of dust-collecting systems. 33.9 Section 33.9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN...

  15. 30 CFR 33.9 - Certification of dust-collecting systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Certification of dust-collecting systems. 33.9 Section 33.9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN...

  16. 30 CFR 33.9 - Certification of dust-collecting systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Certification of dust-collecting systems. 33.9 Section 33.9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN...

  17. 30 CFR 33.36 - Method of drilling; combination unit or dust-collecting system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Method of drilling; combination unit or dust... ROCK DRILLING IN COAL MINES Test Requirements § 33.36 Method of drilling; combination unit or dust-collecting system. Drilling shall be conducted in accordance with the applicant's specifications...

  18. 30 CFR 33.36 - Method of drilling; combination unit or dust-collecting system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Method of drilling; combination unit or dust... ROCK DRILLING IN COAL MINES Test Requirements § 33.36 Method of drilling; combination unit or dust-collecting system. Drilling shall be conducted in accordance with the applicant's specifications...

  19. 30 CFR 33.9 - Certification of dust-collecting systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Certification of dust-collecting systems. 33.9 Section 33.9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN...

  20. Dust storm contributions to airborne particulate matter in Reykjavík, Iceland

    NASA Astrophysics Data System (ADS)

    Thorsteinsson, Throstur; Gísladóttir, Guđrún; Bullard, Joanna; McTainsh, Grant

    2011-10-01

    Episodes of high levels of particulate matter (PM) in Reykjavík occur several times a year. The main sources of daily variation in PM are traffic or highly localized (e.g. construction) sources, however several episodes have been identified where these are not the cause. Examining PM10 (diameter < 10 μm) levels around the time when dust storms are seen on satellite images, and verifying that the weather conditions are favorable for the duration of the high levels of PM (>50-100 μg m-3; 30-min average), demonstrates that dust storms are the source of these increased levels of PM10. Since satellite coverage is sparse, visual confirmation of many such peaks in PM10 cannot be achieved. The level of pollution measured in Reykjavík during dust storms indicates that at least 200 kg s-1 of PM10 sized material is being eroded and transported away from sand plains ˜110 km away - this equates to an emission rate of 35 g m2 h-1. The source regions for dust storms in Iceland are the sandur areas on the southern coast of Iceland, and regions close to the glaciers. With climate warming, and fast retreating glaciers, the potential source regions in Iceland are rapidly increasing.

  1. Swine confinement buildings: effects of airborne particles and settled dust on airway smooth muscles.

    PubMed

    Demanche, Annick; Bonlokke, Jakob; Beaulieu, Marie-Josee; Assayag, Evelyne; Cormier, Yvon

    2009-01-01

    Swine confinement workers are exposed to various contaminants. These agents can cause airway inflammation and bronchoconstriction. This study was undertaken to evaluate if the bronchoconstrictive effects of swine barn air and settled dust are mediated by endotoxin, and if these effects are directly mediated on airway smooth muscles. Mouse tracheas where isolated and mounted isometrically in organ baths. Tracheas, with or without epithelium, were attached to a force transducer and tension was recorded. Concentrated swine building air at 68 EU/ml or settled dust extract at 0.01 g/ml were added for 20 minutes and tracheal smooth muscle contraction was measured. Direct role of LPS was assessed by removing it from air concentrates with an endotoxin affinity resin. Swine barn air and settled dust extract caused contraction of tracheal smooth muscle by 26 and 20%, respectively, of the maximal induced by methacholine. Removal of epithelium did not affect the contractile effects. LPS alone and LPS with peptidoglycans did not induce contraction. However, when endotoxin was removed from swine barn air concentrates, it lost 24% of its contractile effect. Concentrated swine barn air and settled dust have direct effects on airway smooth muscles. This effect is partially due to LPS but a synergy with other components of the environment of swine confinement buildings is required. PMID:20047256

  2. Collecting Comet Samples by ER-2 Aircraft: Cosmic Dust Collection During the Draconid Meteor Shower in October 2012

    NASA Technical Reports Server (NTRS)

    Bastien, Ron; Burkett, P. J.; Rodriquez, M.; Frank, D.; Gonzalez, C.; Robinson, G.-A.; Zolensky, M.; Brown, P.; Campbell-Brown, M.; Broce, S.; Kapitzke, M.; Moes, T.; Steel, D.; Williams, T.; Gearheart, D.

    2014-01-01

    Many tons of dust grains, including samples of asteroids and comets, fall from space into the Earth's atmosphere each day. NASA periodically collects some of these particles from the Earth's stratosphere using sticky collectors mounted on NASA's high-flying aircraft. Sometimes, especially when the Earth experiences a known meteor shower, a special opportunity is presented to associate cosmic dust particles with a known source. NASA JSC's Cosmic Dust Collection Program has made special attempts to collect dust from particular meteor showers and asteroid families when flights can be planned well in advance. However, it has rarely been possible to make collections on very short notice. In 2012, the Draconid meteor shower presented that opportunity. The Draconid meteor shower, originating from Comet 21P/Giacobini-Zinner, has produced both outbursts and storms several times during the last century, but the 2012 event was not predicted to be much of a show. Because of these predictions, the Cosmic Dust team had not targeted a stratospheric collection effort for the Draconids, despite the fact that they have one of the slowest atmospheric entry velocities (23 km/s) of any comet shower, and thus offer significant possibilities of successful dust capture. However, radar measurements obtained by the Canadian Meteor Orbit Radar during the 2012 Draconids shower indicated a meteor storm did occur October 8 with a peak at 16:38 (+/-5 min) UTC for a total duration of approximately 2 hours.

  3. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

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

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

    PubMed

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

    2015-08-17

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

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

    PubMed Central

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

    2015-01-01

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

  6. Estimation of Collection Efficiency Change of Moving Granular Bed Filter by Dust Load

    SciTech Connect

    Furuuchi, M.; Hata, M.; Kanaoka, C.; Kawaminami, Y.

    2002-09-18

    Final goal of this study is to theoretically describe effects of influencing factors on the performance of the coke bed filter as a material classifier and to predict its optimal operating condition. In this paper, the author focuses on the basic investigation on collection mechanism of a fixed coke bed filter on the basis of the depth filtration theory, in which an influence of dust load on the dust collection efficiency.

  7. New house dust collection system and its use in a study of asthma in dust mite sensitive children in Raleigh, North Carolina

    SciTech Connect

    Lindstrom, A.B.; Beck, M.A.; Henry, M.M.; Barnes, D.M.; Henderson, F.W.

    1993-01-01

    A prototype dust collection system, the House Dust Vacuum One (HDVI), was designed for use in a study to investigate the relationship between house dust mite antigen levels and the presence of asthma in dust mite sensitive children. The HDVI was designed for the collection of dust samples from all potentially relevant domestic substrates, with the primary sampling objective being the retrieval at least 100 mg of sample material. During the winter of 1991-92, dust samples were collected from six different microenvironments in the homes of 49 dust mite sensitive children living in the Raleigh, NC metropolitan area. In addition to the standard antigen immunoassay, the performance of the HDVI was assessed by conducting side by side comparison tests using two alternative antigen collection systems. Microenvironmental antigen concentrations were found to be lognormally distributed within the test homes and within each microenvironment. With the relatively large quantity of sample material collected and the ease with which the HDVI was able to collect samples from a wide variety of substrates, the new unit was determined to be well suited for surface dust and dust mite antigen collection studies.

  8. Waveband selection within 400-4000  cm-1 of optical identification of airborne dust in coal mine tunneling face.

    PubMed

    Wang, Wenzheng; Wang, Yanming; Shi, Guoqing

    2016-04-10

    Aimed at the optical evaluation of pollution levels caused by rock dust in an underground coal mine tunneling face, the optimal detection line and optical channel were investigated. The spatial distribution of airborne rock dust under local mining and ventilation conditions was simulated by the computational fluid dynamics method; thus, combined with the scattering and absorption properties of dust particles and gas molecules, the spectral transmission characteristics of a polluted atmosphere, including dust aerosols within 400-4000  cm-1, were obtained. By eliminating the optical background of mine gases, the pure infrared signals of rock dust were further analyzed. Based on the comparison results, the detection line, which is 1.5 m high and 0.3 m away from the right wall, was determined to be the best observation position, and a waveband of 1505-1525  cm-1 was selected to estimate the dust concentration. In addition, a dual-band detection method was presented, which can simultaneously identify the dust distribution and dispersion.

  9. Transport of mineral dust derived from airborne wind lidar measurements during SALTRACE

    NASA Astrophysics Data System (ADS)

    Chouza, Fernando; Reitebuch, Oliver; Groß, Silke; Rahm, Stephan; Freudenthaler, Volker; Toledano, Carlos; Weinzierl, Bernadett

    2015-04-01

    During the SALTRACE field experiment conducted between the 10 of June and the 15 of July 2013, the transport and properties of Saharan dust were characterized by a 2-µm Doppler wind lidar (DWL) deployed on the DLR Falcon 20 research aircraft. Unlike aerosol lidars, the DLW is able to simultaneously measure wind fields and -by means of an adequate calibration- aerosol optical properties, which is more adequate for aerosol transport studies. The retrieved horizontal and vertical wind speed provide a direct observation of dust long range transport mechanisms across the Atlantic (e.g. by the African easterly jet) from Western Africa to the Caribbean. Vertical wind observations revealed the structure of island induced lee waves in the Cape Verde and Barbados regions. A novel method for the calibration of DWLs based on simultaneous measurements with a ground-based aerosol lidar and sun photometer was developed. After being calibrated, the system is able to retrieve quantitative aerosol backscatter and extinction coefficients, which is usually not obtained from coherent lidars. Results from the validation with a ground-based aerosol lidar in Barbados and the CALIPSO satellite instrument will be discussed.

  10. Composition of Dust Particles Collected in the Inner Coma of Comet 67P/Churymumo-Gerasimenko by Rosetta

    NASA Astrophysics Data System (ADS)

    Hilchenbach, M.; Kissel, J.; Langevin, Y.; Briois, C.; Koch, A.; Schulz, R.; Silen, J.; Altobelli, N.; Altwegg, K.; Baklouti, D.; Bardyn, A.; Colangeli, L.; Cottin, H.; Engrand, C.; Fischer, H.; Fray, N.; Glasmachers, A.; Grün, E.; Haerendel, G.; Henkel, H.; Höfner, H.; Hornung, K.; Jessberger, E.-K.; Lehto, H.; Ligier, N.; Martin, P.; Merouane, S.; Orthous-Daunay, F.-R.; Paquette, J.; Raulin, F.; Le Roy, L.; Rynö, J.; Silieström, S.; Steiger, W.; Stenzel, O.; Stephan, T.; Thirkell, L.; Thomas, R.; Torkar, K.; Varmuza, K.; Wanczek, K.-P.; Zaprudin, B.

    2016-08-01

    The dust particle instrument COSIMA - COmetary Secondary Ion Mass Analyser - on board ESA’s ROSETTA mission is collecting and analyzing dust particles in the inner coma of Jupiter-family comet 67P/Churyumov-Gerasimenko.

  11. The development and the tests of the electrostatic probe for dust particle collection in thermonuclear reactors

    NASA Astrophysics Data System (ADS)

    Begrambekov, L. B.; Voityuk, A. N.; Zakharov, A. M.

    2016-09-01

    Formation of dust particles in thermonuclear reactors can greatly affect the plasma parameters and lead to accumulation of tritium. The rates of formation and deposition of dust need to be measured, and the parameters of formation of dust particles and clusters need to be studied. A model of a device for collection of fine conductive particles capable of removing them from the reactor chamber for future research is proposed in this paper. The dust collector's operation is based on a principle of applied electrostatic field. The model was tested in different operating conditions: in vacuum, at the atmospheric pressure in the atmosphere of air and dry nitrogen. The experiments were conducted with a stationary system and with the dust collector in motion relative to the dusty surface. It is shown that, during the probe moving relative to the surface, it can remove up to 95% of fine tungsten particles with sizes ranging from 1 to 10 μm.

  12. Mechanical intervention for reducing dust concentration in traditional rice mills.

    PubMed

    Pranav, Prabhanjan K; Biswas, Mrinmoy

    2016-08-01

    A huge number of workers are employed in traditional rice mills where they are potentially exposed to dust. In this study a dust collection system was developed to capture the airborne dust in the rice mill. The feeding and sieving section of the mill was identified as major dust creating zone. The dust was captured by creating suitable air stream at feeding and sieving sections of the mill and collected in cyclone dust collector. The air stream was created by blower which was selected on the basis to get minimum air speed of 0.5 m/s in the working zones of workers. It was observed that the developed system is successfully collects the significant amount of dust and able to reduce the dust concentration up to 58%. Further, the respirable dust concentration reduced to below 5 mg/m(3) throughout the mill which is within the recommended limit of dust exposure.

  13. Mechanical intervention for reducing dust concentration in traditional rice mills

    PubMed Central

    PRANAV, Prabhanjan K.; BISWAS, Mrinmoy

    2016-01-01

    A huge number of workers are employed in traditional rice mills where they are potentially exposed to dust. In this study a dust collection system was developed to capture the airborne dust in the rice mill. The feeding and sieving section of the mill was identified as major dust creating zone. The dust was captured by creating suitable air stream at feeding and sieving sections of the mill and collected in cyclone dust collector. The air stream was created by blower which was selected on the basis to get minimum air speed of 0.5 m/s in the working zones of workers. It was observed that the developed system is successfully collects the significant amount of dust and able to reduce the dust concentration up to 58%. Further, the respirable dust concentration reduced to below 5 mg/m3 throughout the mill which is within the recommended limit of dust exposure. PMID:26829976

  14. Mineralogical analysis of dust collected from typical recycling line of waste printed circuit boards.

    PubMed

    Wang, Fangfang; Zhao, Yuemin; Zhang, Tao; Duan, Chenlong; Wang, Lizhang

    2015-09-01

    As dust is one of the byproducts originating in the mechanical recycling process of waste printed circuit boards such as crushing and separating, from the viewpoints of resource reuse and environmental protection, an effective recycling method to recover valuable materials from this kind of dust is in urgent need. In this paper, detailed mineralogical analysis on the dust collected from a typical recycling line of waste printed circuit boards is investigated by coupling several analytical techniques. The results demonstrate that there are 73.1wt.% organic matters, 4.65wt.% Al, 4.55wt.% Fe, 2.67wt.% Cu and 1.06wt.% Pb in the dust, which reveals the dust is worthy of reuse and harmful to environment. The concentration ratios of Fe, Mn and Zn can reach 12.35, 12.33 and 6.67 respectively by magnetic separation. The yield of dust in each size fraction is nonuniform, while the yield of -0.75mm size fraction is up to 51.15wt.%; as the particle size decreases, the content of liberated metals and magnetic materials increase, and metals are mainly in elemental forms. The F, Cl and Br elements combing to C in the dust would make thermal treatment dangerous to the environment. Based on these results, a flowsheet to recycle the dust is proposed. PMID:26117419

  15. Mineralogical analysis of dust collected from typical recycling line of waste printed circuit boards.

    PubMed

    Wang, Fangfang; Zhao, Yuemin; Zhang, Tao; Duan, Chenlong; Wang, Lizhang

    2015-09-01

    As dust is one of the byproducts originating in the mechanical recycling process of waste printed circuit boards such as crushing and separating, from the viewpoints of resource reuse and environmental protection, an effective recycling method to recover valuable materials from this kind of dust is in urgent need. In this paper, detailed mineralogical analysis on the dust collected from a typical recycling line of waste printed circuit boards is investigated by coupling several analytical techniques. The results demonstrate that there are 73.1wt.% organic matters, 4.65wt.% Al, 4.55wt.% Fe, 2.67wt.% Cu and 1.06wt.% Pb in the dust, which reveals the dust is worthy of reuse and harmful to environment. The concentration ratios of Fe, Mn and Zn can reach 12.35, 12.33 and 6.67 respectively by magnetic separation. The yield of dust in each size fraction is nonuniform, while the yield of -0.75mm size fraction is up to 51.15wt.%; as the particle size decreases, the content of liberated metals and magnetic materials increase, and metals are mainly in elemental forms. The F, Cl and Br elements combing to C in the dust would make thermal treatment dangerous to the environment. Based on these results, a flowsheet to recycle the dust is proposed.

  16. Collection and curation of interplanetary dust particles recovered from the stratosphere

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Warren, Jack L.

    1994-01-01

    Since May 1981, the National Aeronautics and Space Administration (NASA) has used aircraft to collect interplanetary dust particles (IDP's) from Earth's stratosphere. Specially designed dust collectors are prepared for flight and processed after flight in an ultraclean (Class-100) laboratory constructed for this purpose at the Lyndon B. Johnson Space Center (JSC) in Houston, Texas. Particles are individually retrieved from the collectors, examined, and cataloged, and then made available to the scientific community for research. Interplanetary dust thereby joins lunar samples and Antarctic meteorites as a critical extraterrestrial material being curated at JSC.

  17. Endotoxin levels in settled airborne dust in European schools: the HITEA school study.

    PubMed

    Jacobs, J H; Krop, E J M; Borras-Santos, A; Zock, J-P; Taubel, M; Hyvarinnen, A; Pekkanen, J; Doekes, G; Heederik, D J J

    2014-04-01

    Indoor exposure to microbial agents is known to influence respiratory health. Besides home exposure, exposure in schools can affect respiratory health. In this study, we measured endotoxin in settled dust in primary schools in three European countries from three different geographical regions with different climates. Our aim was to characterize endotoxin levels in primary schools and evaluate associations with potential determinants. Endotoxin levels were repeatedly assessed in 23 schools in Spain (n = 7), the Netherlands (n = 10), and Finland (n = 6) using electrostatic dustfall collectors. In total, 645 measurements were taken in 237 classrooms. Endotoxin levels differed significantly between countries; Dutch schools had the highest levels, while Finnish schools showed the lowest levels. In each country, differences in endotoxin levels were observed between schools and over the sampling periods. Estimates improved after adjustment for sampling period. Factors affecting endotoxin levels in a school differed per country. In general, endotoxin levels were higher in lower grades and in classrooms with higher occupancy. School endotoxin levels may contribute significantly to total endotoxin exposure in children and teachers. As the correlation between the repeated measurements is reasonable, single endotoxin measurements form a reasonable basis for estimating annual endotoxin levels in schools.

  18. Instrument Would Detect and Collect Biological Aerosols

    NASA Technical Reports Server (NTRS)

    Savoy, Steve; Mayo, Mike

    2006-01-01

    A proposed compact, portable instrument would sample micron-sized airborne particles, would discriminate between biological ones (e.g., bacteria) and nonbiological ones (e.g., dust particles), and would collect the detected biological particles for further analysis. The instrument is intended to satisfy a growing need for means of rapid, inexpensive collection of bioaerosols in a variety of indoor and outdoor settings. Purposes that could be served by such collection include detecting airborne pathogens inside buildings and their ventilation systems, measuring concentrations of airborne biological contaminants around municipal waste-processing facilities, monitoring airborne effluents from suspected biowarfare facilities, and warning of the presence of airborne biowarfare agents

  19. Dust particles from comets and asteroids collected at the Earth's orbit: Parent-daughter relationships

    NASA Technical Reports Server (NTRS)

    Jackson, A. A.; Zook, H. A.

    1991-01-01

    The relative contributions of comets and asteroids to the reservoir of dust in the interplanetary medium is not well known. There are direct observations of dust released from comets and there is evidence to associate the IRAS dust bands with possible collisions of Asteroids in the main belt. It is believed that one may combine lab analysis of the physics and chemistry of captured particles with orbital data in order to identify comet and asteroid parent bodies. It is possible to use the collected orbits of the dust to connect with its source in two ways. One is to consider the long time orbit evolution of the dust under Poynting-Robertson drag. The other is to look at the prompt orbit change of dust from comets onto trajectories that intersect the earth's orbit. In order to characterize the orbits of dust particles evolved over a long period of time, a study of its orbital evolution was undertaken. Various parameters associated with these dust orbits as they cross the Earth's orbit were considered in order to see if one may discriminate between particles evolved from comets and asteroids. The method was to calculate by a numerical procedure the orbits of dust particles after they left their parent bodies. It appears that as the particles pass the Earth's orbit, asteroidal grains and cometary grains can be differentiated on the basis of their measured orbital eccentricities even after much planetary perturbation. Broad parent daughter associations can be made on this basis from measurement of their trajectories intercepted in earth orbit.

  20. A microfluidics-based on-chip impinger for airborne particle collection.

    PubMed

    Mirzaee, I; Song, M; Charmchi, M; Sun, H

    2016-06-21

    Capturing airborne particles from air into a liquid is a critical process for the development of many sensors and analytical systems. A miniaturized airborne particle sampling device (microimpinger) has been developed in this research. The microimpinger relies on a controlled bubble generation process produced by driving air through microchannel arrays. The particles confined in the microscale bubbles are captured in the sampling liquid while the bubbles form, are released and travel in a millimetre-scale sealed liquid reservoir. The microchannel arrays in the impinger are fabricated using a soft-lithography method with polydimethylsiloxane (PDMS) as the structural material. To prevent air leakage at the connections, a PDMS-only sealing technique is successfully developed. The hydrophobicity of the microchannel surface is found to be critical for generating continuous and stable bubbles in the bubbling process. A Teflon layer is coated on the walls of a microchannel array by vapor deposition which effectively increases the hydrophobicity of the PDMS. The collection efficiency of the microimpinger is measured by counting different sizes of fluorescent polystyrene latex particles on polycarbonate membrane filters. Collection efficiencies above 90% are achieved. Furthermore, the particle capturing mechanisms during the injection, formation and rise of a single microbubble are investigated by a computational fluid dynamics (CFD) model. The Navier-Stokes equations are solved along with the use of the volume-of-fluid (VOF) method to capture the bubble deformations and the particles are tracked using a Lagrangian equation of motion. The model is also employed to study the effect of bubble size on the collection efficiency of the microimpinger.

  1. A microfluidics-based on-chip impinger for airborne particle collection.

    PubMed

    Mirzaee, I; Song, M; Charmchi, M; Sun, H

    2016-06-21

    Capturing airborne particles from air into a liquid is a critical process for the development of many sensors and analytical systems. A miniaturized airborne particle sampling device (microimpinger) has been developed in this research. The microimpinger relies on a controlled bubble generation process produced by driving air through microchannel arrays. The particles confined in the microscale bubbles are captured in the sampling liquid while the bubbles form, are released and travel in a millimetre-scale sealed liquid reservoir. The microchannel arrays in the impinger are fabricated using a soft-lithography method with polydimethylsiloxane (PDMS) as the structural material. To prevent air leakage at the connections, a PDMS-only sealing technique is successfully developed. The hydrophobicity of the microchannel surface is found to be critical for generating continuous and stable bubbles in the bubbling process. A Teflon layer is coated on the walls of a microchannel array by vapor deposition which effectively increases the hydrophobicity of the PDMS. The collection efficiency of the microimpinger is measured by counting different sizes of fluorescent polystyrene latex particles on polycarbonate membrane filters. Collection efficiencies above 90% are achieved. Furthermore, the particle capturing mechanisms during the injection, formation and rise of a single microbubble are investigated by a computational fluid dynamics (CFD) model. The Navier-Stokes equations are solved along with the use of the volume-of-fluid (VOF) method to capture the bubble deformations and the particles are tracked using a Lagrangian equation of motion. The model is also employed to study the effect of bubble size on the collection efficiency of the microimpinger. PMID:27185303

  2. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    PubMed

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks.

  3. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    PubMed

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks. PMID:26771587

  4. Airborne microorganisms in the African desert dust corridor over the mid-Atlantic ridge, Ocean Drilling Program, Leg 209

    USGS Publications Warehouse

    Griffin, Dale W.; Westphal, Douglas L.; Gray, Michael A.

    2006-01-01

    The objective of this study was to enhance our understanding of the fate and trans-Atlantic transport of dustborne microorganisms from Northern Africa to the Caribbean and Americas, and more specifically to determine if culturable populations could be detected at a mid-ocean site, closer to the source of dust relative to land-based Caribbean sites, during the early summer months of May and June. Between the dates of 22 May and 30 June 2003, daily air samples were collected and evaluated for the presence of culturable bacterial and fungal colony-forming units (CFU). Here we report a statistically significant correlation between daily atmospheric CFU counts at a mid-ocean research site (???15??N, 45??W) and daily desert dust concentrations as determined by the U.S. Navy's Naval Aerosol Analysis and Prediction System (NAAPS) Global Aerosol Model (Honrath et al. (2004). Journal of Geophysical Research, 109; Johnson et al. (2003). Global Biogeochemical Cycles, 17, 1063; Reid et al. (2004). Geophysical Research Letters, 31; Schollaert, Yoder, Westphal, & O'Reilly (2003). Journal of Geophysical Research, 108, 3191). ?? Springer Science+Business Media B.V. 2006.

  5. Airborne Hyperspectral Survey of Afghanistan 2007: Flight Line Planning and HyMap Data Collection

    USGS Publications Warehouse

    Kokaly, Raymond F.; King, Trude V.V.; Livo, K. Eric

    2008-01-01

    Hyperspectral remote sensing data were acquired over Afghanistan with the HyMap imaging spectrometer (Cocks and others, 1998) operating on the WB-57 high altitude NASA research aircraft (http://jsc-aircraft-ops.jsc.nasa.gov/wb57/index.html). These data were acquired during the interval of August 22, 2007 to October 2, 2007, as part of the United States Geological Survey (USGS) project 'Oil and Gas Resources Assessment of the Katawaz and Helmand Basins'. A total of 218 flight lines of hyperspectral remote sensing data were collected over the country. This report describes the planning of the airborne survey and the flight lines that were flown. Included with this report are digital files of the nadir tracks of the flight lines, including a map of the labeled flight lines and corresponding vector shape files for geographic information systems (GIS).

  6. Stratospheric Collection of Dust from Comet 73P/Schwassmann-Wachmann 3

    NASA Technical Reports Server (NTRS)

    Messenger, Scott R.; Walker, Robert M.

    2011-01-01

    Interplanetary dust particles (IDPs) collected in the stratosphere are unique materials that are compositionally distinct from meteorites. Astronomical observations and dynamical models indicate that both asteroids and short-period comets are significant sources of IDPs. IDPs having fragile, porous structures, unequilibrated, anhydrous mineralogy, and high atmospheric entry velocities are thought to derive from comets, whereas asteroidal IDPs are identified by their compact structure, hydrated mineralogy and low atmospheric entry velocities. Uncertainty remains in the classification of asteroidal and cometary IDPs owing to our limited sampling of comets and the asteroid belt and the complex dynamical histories of most IDPs in space. Most IDPs spend thousands of years in space prior to being accreted by the Earth. During this time, dust particles undergo orbital evolution, including gradual reduction in their perihelion and eccentricity as a result of Poynting-Robertson drag. Planetary encounters may also significantly change their orbital parameters. Consequently, it is generally not possible to identify the specific parent body of a given IDP. However, it has been proposed that it is possible to identify dust from comets that have formed Earth-crossing dust trails. In this case, the dust particles have been in space for such a short period of time (a few decades or less) that their orbits have not significantly changed. Furthermore, these fresh IDPs could be identified in the laboratory from their short space-exposure histories (low solar noble gas abundance and lack of solar flare tracks). NASA flew several dedicated IDP collection missions attempting to collect dust from comet 26P/Grigg-Skjellerup, the best candidate identified. Remarkably, many particles from those collectors exhibit unusual properties, including low abundances of solar noble gases and high abundances of presolar grains. These observations are consistent with the dust particles originating from

  7. Vertical distribution of airborne bacterial communities in an Asian-dust downwind area, Noto Peninsula

    NASA Astrophysics Data System (ADS)

    Maki, Teruya; Hara, Kazutaka; Kobayashi, Fumihisa; Kurosaki, Yasunori; Kakikawa, Makiko; Matsuki, Atsushi; Chen, Bin; Shi, Guangyu; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2015-10-01

    Bacterial populations transported from ground environments to the atmosphere get dispersed throughout downwind areas and can influence ecosystem dynamics, human health, and climate change. However, the vertical bacterial distribution in the free troposphere was rarely investigated in detail. We collected aerosols at altitudes of 3000 m, 1000 m, and 10 m over the Noto Peninsula, Japan, where the westerly winds carry aerosols from continental and marine areas. During the sampling period on March 10, 2012, the air mass at 3000 m was transported from the Chinese desert region by the westerly winds, and a boundary layer was formed below 2000 m. Pyrosequencing targeting 16S rRNA genes (16S rDNA) revealed that the bacterial community at 3000 m was predominantly composed of terrestrial bacteria, such as Bacillus and Actinobacterium species. In contrast, those at 1000 m and 10 m included marine bacteria belonging to the classes Cyanobacteria and Alphaproteobacteria. The entire 16S rDNA sequences in the clone libraries were identical to those of the terrestrial and marine bacterial species, which originated from the Chinese desert region and the Sea of Japan, respectively. The origins of air masses and meteorological conditions contribute to vertical variations in the bacterial communities in downwind atmosphere.

  8. 77 FR 12080 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Cotton Dust...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-28

    ... Register on October 5, 2011 (76 FR 61752). Interested parties are encouraged to send comments to the OMB...; Cotton Dust Standard ACTION: Notice. SUMMARY: The Department of Labor (DOL) is submitting the Occupational Safety and Health Administration sponsored information collection request (ICR) titled,...

  9. 78 FR 25308 - Proposed Collection; Comment Request; Coal Mine Dust Sampling Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Mine Safety and Health Administration Proposed Collection; Comment Request; Coal Mine Dust Sampling Devices AGENCY: Mine Safety and Health Administration, Labor. ACTION: 60-Day Notice. SUMMARY: The Department...

  10. 30 CFR 33.36 - Method of drilling; combination unit or dust-collecting system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Method of drilling; combination unit or dust-collecting system. 33.36 Section 33.36 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... ROCK DRILLING IN COAL MINES Test Requirements § 33.36 Method of drilling; combination unit or...

  11. 30 CFR 33.36 - Method of drilling; combination unit or dust-collecting system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Method of drilling; combination unit or dust-collecting system. 33.36 Section 33.36 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... ROCK DRILLING IN COAL MINES Test Requirements § 33.36 Method of drilling; combination unit or...

  12. 30 CFR 33.36 - Method of drilling; combination unit or dust-collecting system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Method of drilling; combination unit or dust-collecting system. 33.36 Section 33.36 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF... ROCK DRILLING IN COAL MINES Test Requirements § 33.36 Method of drilling; combination unit or...

  13. Vertical mass impact and features of Saharan dust intrusions derived from ground-based remote sensing in synergy with airborne in-situ measurements

    NASA Astrophysics Data System (ADS)

    Córdoba-Jabonero, Carmen; Andrey-Andrés, Javier; Gómez, Laura; Adame, José Antonio; Sorribas, Mar; Navarro-Comas, Mónica; Puentedura, Olga; Cuevas, Emilio; Gil-Ojeda, Manuel

    2016-10-01

    A study of the vertical mass impact of Saharan dust intrusions is presented in this work. Simultaneous ground-based remote-sensing and airborne in-situ measurements performed during the AMISOC-TNF campaign over the Tenerife area (Canary Islands) in summertime from 01 July to 11 August 2013 were used for that purpose. A particular dusty (DD) case, associated to a progressively arriving dust intrusion lasting for two days on 31 July (weak incidence) and 01 August (strong incidence), is especially investigated. AERONET AOD and AEx values were ranging, respectively, from 0.2 to 1.4 and 0.35 to 0.05 along these two days. Vertical particle size distributions within fine and coarse modes (0.16-2.8 μm range) were obtained from aircraft aerosol spectrometer measurements. Extinction profiles and Lidar Ratio (LR) values were derived from MPLNET/Micro Pulse Lidar observations. MAXDOAS measurements were also used to retrieve the height-resolved aerosol extinction for evaluation purposes in comparison to Lidar-derived profiles. The synergy between Lidar observations and airborne measurements is established in terms of the Mass Extinction Efficiency (MEE) to calculate the vertical mass concentration of Saharan dust particles. Both the optical and microphysical profilings show dust particles mostly confined in a layer of 4.3 km thickness from 1.7 to 6 km height. LR ranged between 50 and 55 sr, typical values for Saharan dust particles. In addition, this 2-day dust event mostly affected the Free Troposphere (FT), being less intense in the Boundary Layer (BL). In particular, rather high Total Mass Concentrations (TMC) were found on the stronger DD day (01 August 2013): 124, 70 and 21 μg m-3 were estimated, respectively, at FT and BL altitudes and on the near-surface level. This dust impact was enhanced due to the increase of large particles affecting the FT, but also the BL, likely due to their gravitational settling. However, the use of an assumed averaged MEE value can be

  14. Pristine stratospheric collection of interplanetary dust on an oil-free polyurethane foam substrate

    NASA Astrophysics Data System (ADS)

    Messenger, Scott; Nakamura-Messenger, Keiko; Keller, Lindsay P.; Clemett, Simon J.

    2015-08-01

    We performed chemical, mineralogical, and isotopic studies of the first interplanetary dust particles (IDPs) collected in the stratosphere without the use of silicone oil. The collection substrate, polyurethane foam, effectively traps impacting particles, but the lack of an embedding medium results in significant particle fragmentation. Two dust particles found on the collector exhibit the typical compositional and mineralogical properties of chondritic porous interplanetary dust particles (CP-IDPs). Hydrogen and nitrogen isotopic imaging revealed isotopic anomalies of typical magnitude and spatial variability observed in previous CP-IDP studies. Oxygen isotopic imaging shows that individual mineral grains and glass with embedded metal and sulfide (GEMS) grains are dominated by solar system materials. No systematic differences are observed in element abundance patterns of GEMS grains from the dry collection versus silicone oil-collected IDPs. This initial study establishes the validity of a new IDP collection substrate that avoids the use of silicone oil as a collection medium, removing the need for this problematic contaminant and the organic solvents necessary to remove it. Additional silicone oil-free collections of this type are needed to determine more accurate bulk element abundances of IDPs and to examine the indigenous soluble organic components of IDPs.

  15. Electron Microanalysis of Aerosols Collected at Mauna Loa Observatory During an Asian Dust Storm Event

    NASA Astrophysics Data System (ADS)

    Conny, J. M.; Willis, R. D.; Ortiz-Montalvo, D. L.; Colton, A.

    2014-12-01

    Located in the remote marine free troposphere, the Mauna Loa Observatory (MLO) represents a clean airshed that can be used to study anthropogenic pollution influences and long-range transport of aerosol particles from the Asian mainland. Because of the global nature of Asian dust storms, the radiative properties of these particles transported long-range can significantly impact global climate. It has been proposed that aerosols transported to MLO during upslope wind conditions (typically daytime) are local in origin while aerosols transported during downslope conditions (typically nighttime) represent long-range transport in the free troposphere. Twelve PM10 samples (six daytime/nightime pairs) were collected on polycarbonate filters for 72 hours each between March 15 and April 26, 2011. Bulk samples of dust from local sources (road dust, parking lot, lava fields) were collected as well in order to assess the PM10 contribution from local dusts. On March 19-20 the Korea Meteorological Administration documented a significant dust event over the Korean peninsula. Back-trajectory analyses from MLO coupled with local wind speed and wind direction data suggest that this dust event may have been captured during the MLO sampling campaign. MLO samples were analyzed by computer-controlled scanning electron microscopy (CCSEM) coupled with energy-dispersive X-ray spectrometry (EDX) and particles were sorted into compositionally-distinct particle types which were then compared across the sample set. Concentrations of particle types expected to be associated with Asian dust were observed to peak in one pair of daytime/nighttime samples collected between March 22 and March 28. Manual microscopic characterization of suspected Asian dust particles and local dust particles was carried out using electron backscatter diffraction (EBSD) in conjunction with EDX and focussed ion beam SEM (FIB-SEM) in an effort to characterize differences in physicochemical or radiative properties of

  16. Analysis of Measurements of Saharan Dust by Airborne and Ground-based Remote Sensing Methods during the Puerto Rico Dust Experiment (PRIDE)

    NASA Technical Reports Server (NTRS)

    Reid, Jeffrey S.; Kinney, James E.; Westphal, Douglas L.; Holben, Brent N.; Welton, E. Judd; Tsay, Si-Chee; Eleuterio, Daniel P.; Campbell, James; Christopher, Sundar A.; Jonsson, Haflidi H.

    2003-01-01

    For 26 days in mid-June and July 2000, a research group comprised of U.S. Navy, NASA, and university scientists conducted the Puerto Rico Dust Experiment (PRIDE). In this paper we give a brief overview of mean meteorological conditions during the study. We focus on findings on African dust transported into the Caribbean utilizing Navajo aircraft and AERONET Sun photometer data. During the study midvisible aerosol optical thickness (AOT) in Puerto Rico averaged 0.25, with a maximum less than 0.5 and with clean marine periods of _0.08. Dust AOTs near the coast of Africa (Cape Verde Islands and Dakar) averaged _0.4, 30% less than previous years. By analyzing dust vertical profiles in addition to supplemental meteorology and MPLNET lidar data we found that dust transport cannot be easily categorized into any particular conceptual model. Toward the end of the study period, the vertical distribution of dust was similar to the commonly assumed Saharan Air Layer (SAL) transport. During the early periods of the study, dust had the highest concentrations in the marine and convective boundary layers with only a, weak dust layer in the SAL being present, a state usually associated with wintertime transport patterns. We corroborate the findings of Maring et al. that in most cases, there was an unexpected lack of vertical stratification of dust particle size. We systematically analyze processes which may impact dust vertical distribution and determine and speculate that dust vertical distribution predominately influenced by flow patterns over Africa and differential advection couple with mixing by easterly waves and regional subsidence.

  17. COLLECTION OF AIRBORNE PARTICLES BY A HIGH-GRADIENT PERMANENT MAGNETIC METHOD

    SciTech Connect

    Cheng, Mengdawn; Allman, Steve L; Ludtka, Gerard Michael; Avens, Larry R

    2014-01-01

    We report on the use of magnetic force in collection of airborne particles by a high- gradient permanent magnetic separation (HGPMS) device. Three aerosol particles of different magnetic susceptibility (NaCl, CuO, and Fe2O3) were generated in the electrical mobility size range of 10 to 200 nm and were used to study HGPMS collection. One HGPMS matrix element, made of stainless steel wool, was used in the device configuration. Three flow rates were selected to simulate the environmental wind speeds of interest to the study. Magnetic force was found to exhibit an insignificant effect on the separation of NaCl particles, even in the HGPMS configuration. Diffusion was a major mechanism in the removal of the diamagnetic particles; however, diffusion is insignificant under the influence of a high-gradient magnetic field for paramagnetic or ferromagnetic particles. The HGPMS showed high-performance collection (> 99%) of paramagnetic CuO and ferromagnetic Fe2O3 particles for particle sizes greater than or equal to 60 nm. As the wind speed increases, the influence of the magnetic force weakens, and the capability to remove particles from the gas stream diminishes. The results suggest that the HGPMS principle could be explored for development of an advanced miniaturized passive aerosol collector.

  18. Composition of Dust Particles Collected in the Coma of Comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Hilchenbach, Martin; Kissel, Jochen; Langevin, Yves; Briois, Christelle; Koch, Andreas; Schulz, Rita; Silen, Johan; Rynö, Jouni

    2016-04-01

    The COmetary Secondary Ion Mass Analyser (COSIMA) is a dust particle composition analyzing instrument onboard the ROSETTA spacecraft orbiting comet 67P/Churyumov-Gerasimenko since August 2014. COSIMA is collecting cometary particles on metal targets in the inner coma, identifies the collected particle on microscopic images and analyses their composition by secondary ion mass spectrometry. We will report on the high resolution mass spectra containing positive or negative ions of elements, organic molecules and molecular fragments originating from the cometary particle surfaces.

  19. CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF FLOOR DUST SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.19)

    EPA Science Inventory

    This SOP describes the method for collecting a floor dust sample from carpet. Dust samples will be collected in the room that the child uses most at home and/or at day care using a High Volume Small Surface Sampler (HVS3). In addition, participants will also be asked to donate a ...

  20. Airborne manganese as dust vs. fume determining blood levels in workers at a manganese alloy production plant.

    PubMed

    Park, Robert M; Baldwin, Mary; Bouchard, Maryse F; Mergler, Donna

    2014-12-01

    The appropriate exposure metrics for characterizing manganese (Mn) exposure associated with neurobehavioral effects have not been established. Blood levels of Mn (B-Mn) provide a potentially important intermediate marker of Mn airborne exposures. Using data from a study of a population of silicon- and ferro-manganese alloy production workers employed between 1973 and 1991, B-Mn levels were modeled in relation to prior Mn exposure using detailed work histories and estimated respirable Mn concentrations from air-sampling records. Despite wide variation in exposure levels estimated for individual jobs, duration of employment (exposure) was itself a strong predictor of B-Mn levels and strongest when an 80-day half-life was applied to contributions over time (t=6.95, 7.44, respectively; p<10(-5)). Partitioning exposure concentrations based on process origin into two categories: (1) "large" respirable particulate (Mn-LRP) derived mainly from mechanically generated dust, and (2) "small" respirable particulate (Mn-SRP) primarily electric furnace condensation fume, revealed that B-Mn levels largely track the small, fume exposures. With a half-life of 65 days applied in a model with cumulative exposure terms for both Mn-LRP (t=-0.16, p=0.87) and Mn-SRP (t=6.45, p<10(-5)), the contribution of the large-size fraction contribution was negligible. Constructing metrics based on the square root of SRP exposure concentrations produced a better model fit (t=7.87 vs. 7.44, R(2)=0.2333 vs. 0.2157). In a model containing both duration (t=0.79, p=0.43) and (square root) fume (t=2.47, p=0.01) metrics, the duration term was a weak contributor. Furnace-derived, small respirable Mn particulate appears to be the primary contributor to B-Mn levels, with a dose-rate dependence in a population chronically exposed to Mn, with air-concentrations declining in recent years. These observations may reflect the presence of homeostatic control of Mn levels in the blood and other body tissues and be

  1. China Dust

    Atmospheric Science Data Center

    2013-04-16

    ... SpectroRadiometer (MISR) nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a ... arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the ...

  2. Evaluation of a low-cost electrostatic dust fall collector for indoor air endotoxin exposure assessment.

    PubMed

    Noss, Ilka; Wouters, Inge M; Visser, Maaike; Heederik, Dick J J; Thorne, Peter S; Brunekreef, Bert; Doekes, Gert

    2008-09-01

    Exposure to endotoxin in home environments has become a key issue in asthma and allergy research. Most studies have analyzed floor or mattress dust endotoxin, but its validity as a proxy for airborne exposure is unknown, while active airborne dust sampling is not feasible in large-scale population studies because of logistic and financial limitations. We therefore developed and evaluated a simple passive airborne dust collection method for airborne endotoxin exposure assessment. We explored an electrostatic dust fall collector (EDC), consisting of a 42- by 29.6-cm-sized folder with four electrostatic cloths exposed to the air. The EDC was tested during two 14-day periods in seven nonfarm and nine farm homes and in farm stables. In parallel, active airborne dust sampling was performed with Harvard impactors and floor dust collected by vacuuming, using nylon sampling socks. The endotoxin levels could be measured in all EDC cloth extracts. The levels (in EU/m(2)) between EDCs used simultaneously or in different sampling periods in the same home correlated strongly (r > 0.8). EDC endotoxin also correlated moderately to strongly (r = 0.6 to 0.8) with the endotoxin measured by active airborne dust sampling and living room floor dust sampling and-in farm homes-with the endotoxin captured by the EDC in stables. In contrast, endotoxin levels measured by floor dust sampling showed only a poor correlation with the levels measured by active airborne dust sampling. We therefore conclude that measuring endotoxin levels with the EDC is a valid measure of average airborne endotoxin exposure, while reproducibility over time is at least equivalent to that of reservoir dust analyses.

  3. Effective localized collection and identification of airborne species through electrodynamic precipitation and SERS-based detection

    PubMed Central

    Lin, En-Chiang; Fang, Jun; Park, Se-Chul; Johnson, Forrest W.; Jacobs, Heiko O.

    2013-01-01

    Various nanostructured sensor designs currently aim to achieve or claim single molecular detection by a reduction of the active sensor size. However, a reduction of the sensor size has the negative effect of reducing the capture probability considering the diffusion-based analyte transport commonly used. Here we introduce and apply a localized programmable electrodynamic precipitation concept as an alternative to diffusion. The process provides higher collection rates of airborne species and detection at lower concentration. As an example, we compare an identical nanostructured surfaced-enhanced Raman spectroscopy sensor with and without localized delivery and find that the sensitivity and detection time is improved by at least two orders of magnitudes. Localized collection in an active-matrix array-like fashion is also tested, yielding hybrid molecular arrays on a single chip over a broad range of molecular weights, including small benzenethiol (110.18 Da) and 4-fluorobenzenethiol (128.17 Da), or large macromolecules such as anti-mouse IgG (~150 kDa). PMID:23535657

  4. Spectroscopic Characterization of Dust-Fall Samples Collected from Greater Cairo, Egypt.

    PubMed

    Shaltout, Abdallah A; Allam, Mousa A; Mostafa, Nasser Y; Heiba, Zein K

    2016-04-01

    This work aimed to characterize dust-fall samples collected from street's trees in Greater Cairo (GC), Egypt, and its surroundings by different spectroscopic techniques, namely; X-ray diffraction (XRD), attenuated total-reflection Fourier transform infrared (ATR-FTIR), particle-size analyzer, and scanning electron microscopy (SEM) combined with energy dispersive X-ray measurements. Samples were collected from 19 different locations inside and outside of GC. Quantitative phase analysis of the dust-fall samples was performed using the Rietveld method. Results showed that the most frequently observed phases in the dust-fall samples were calcite (CaCO3), dolomite (CaMg(CO3)2), gypsum (CaSO4·2H2O), and quartz (SiO2) with average concentrations of 39 ± 16, 8 ± 7, 22 ± 13, and 33 ± 14 wt%, respectively. The occurrence of these constituents referred to a combination of different anthropogenic and natural sources. The ATR-FTIR results are in good agreements with XRD data of the different observed phases. Based on the SEM and particle-size measurements, quantitative determination of the particle-size distribution was described. It was found that not only the large-sized particles are deposited but also the small-sized ones (PM10 and PM2.5). In addition, the particle size of the collected dust-fall samples varied from 0.1 to 200 µm with an average particle size of 17.36 µm; however, the particle size ranged from 2.5 to 40 µm predominated in all of the dust-fall samples. PMID:26710766

  5. Soil sample collection and analysis for the Fugitive Dust Characterization Study

    NASA Astrophysics Data System (ADS)

    Ashbaugh, Lowell L.; Carvacho, Omar F.; Brown, Michael S.; Chow, Judith C.; Watson, John G.; Magliano, Karen C.

    A unique set of soil samples was collected as part of the Fugitive Dust Characterization Study. The study was carried out to establish whether or not source profiles could be constructed using novel analytical methods that could distinguish soil dust sources from each other. The soil sources sampled included fields planted in cotton, almond, tomato, grape, and safflower, dairy and feedlot facilities, paved and unpaved roads (both urban and rural), an agricultural staging area, disturbed land with salt buildup, and construction areas where the topsoil had been removed. The samples were collected using a systematic procedure designed to reduce sampling bias, and were stored frozen to preserve possible organic signatures. For this paper the samples were characterized by particle size (percent sand, silt, and clay), dry silt content (used in EPA-recommended fugitive dust emission factors), carbon and nitrogen content, and potential to emit both PM 10 and PM 2.5. These are not the "novel analytical methods" referred to above; rather, it was the basic characterization of the samples to use in comparing analytical methods by other scientists contracted to the California Air Resources Board. The purpose of this paper is to document the methods used to collect the samples, the collection locations, the analysis of soil type and potential to emit PM 10, and the sample variability, both within field and between fields of the same crop type.

  6. Conveyor dust control

    SciTech Connect

    Goldbeck, L.

    1999-11-01

    In the past, three different approaches have been used to control dust arising at conveyor load zones. They are: Dust Containment consists of those mechanical systems employed to keep material inside the transfer point with the main material body. Dust Suppression systems increase the mass of suspended dust particles, allowing them to fall from the air stream. Dust Collection is the mechanical capture and return of airborne material after it becomes airborne from the main material body. Previously, these three approaches have always been seen as separate entities. They were offered by separate organizations competing in the marketplace. The three technologies vied for their individual piece of the rock, at the expense of the other technologies (and often at the expense of overall success). There have been considerable amounts of I`m better selling, as well as finger pointing at the other systems when problems arose. Each system claimed its own technology was the best, providing the most effective, most cost-efficient, most maintenance-free solution to fugitive material.

  7. Seasonal variations of sugars in atmospheric particulate matter from Gosan, Jeju Island: Significant contributions of airborne pollen and Asian dust in spring

    NASA Astrophysics Data System (ADS)

    Fu, Pingqing; Kawamura, Kimitaka; Kobayashi, Minoru; Simoneit, Bernd R. T.

    2012-08-01

    Sugars are important water-soluble organic constituents of atmospheric particulate matter (PM). In order to better understand the sources and seasonal variations of sugars in aerosols, primary saccharides (fructose, glucose, sucrose, and trehalose) and sugar alcohols (arabitol and mannitol), together with levoglucosan, have been studied in ambient aerosols at Gosan, Jeju Island in the western North Pacific, the downwind region of the Asian outflow, using gas chromatography-mass spectrometry. The results showed that the sugar composition varied seasonally with a total concentration range of 6.8-1760 ng m-3 (mean 246 ng m-3). The total identified sugars had the highest concentration in April, the spring bloom season at Jeju Island, when sucrose contributed up to 80% of the total sugars. The dominance of sucrose was also detected in pollen samples, suggesting that pollen can contribute significantly to sucrose in aerosols during the spring bloom. The seasonal variation of trehalose is consistent with those of non-sea-salt Ca2+ and δ13C of total carbon with elevated levels during the Asian dust storm events. This study indicates that sugar compounds in atmospheric PM over East Asia can be derived from biomass burning, Asian dust, and primary biological aerosols such as fungal spores and pollen. Furthermore, this study supports the idea that sucrose could be used as a tracer for airborne pollen grains, and trehalose as a tracer for Asian dust outflow.

  8. A Scheme for Dust Collection and Analysis: A Student-Led Project

    NASA Astrophysics Data System (ADS)

    Brockie, I.; Kelley, M. C.; Hirzel, A.; Gumbel, J.

    2012-12-01

    Under New York Space Grant funding, we have designed a dust collector to be launched on a NASA Terrier-Orion rocket in 2014 and then recovered in the waters off Wallops Island, VA. The prime target is the meteoric dust layer near 95 km, but we will also see if dust filtering exists lower in the atmosphere from this source, using multiple collection strategies. The collector is based on aerogel, the same material used in the Stardust mission, which collected material from the comet tail. This form of glass has an extremely low specific gravity, <0.02. This material will be provided by Stephen Jones, who made the Stardust collector. Collection timing will be provided by the flight-tested Cornell COUGAR GPS system. Analysis will be done at San Diego State University (SDSU) in William Tong's laboratory. The SDSU system is a multiple laser-based unit with a sensitivity of 10-8 moles. We will also use this new technology to study some of the Stardust material that was saved for this purpose.

  9. Aging of mineral dust during transport from the Sahara into the Cape Verde area - results from airborne measurements during SAMUM

    NASA Astrophysics Data System (ADS)

    Weinzierl, B.; Sauer, D.; Esselborn, M.; Petzold, A.; Veira, A.; Rose, M.; Mund, S.; Wirth, M.; Ansmann, A.; Tesche, M.; Groß, S.; Freudenthaler, V.

    2012-04-01

    The Saharan Mineral Dust Experiment (SAMUM) was conducted to better understand the properties of fresh and aged mineral dust. Within SAMUM, two field missions were performed: SAMUM-1 (summer 2006, Morocco) focused on the chemical, microphysical, optical and radiative properties of fresh dust aerosol in the vertical column over the Sahara, while SAMUM-2 (winter 2008, Cape Verde) concentrated on the properties of aged dust and the mixing of mineral dust with biomass burning aerosol. During both field experiments, the DLR Falcon research aircraft was equipped with an extensive set of aerosol instruments for size, volatility, and absorption measurements, impactor sampling for chemical analyses and with a nadir-looking High Spectral Resolution Lidar (HSRL). In the Cape Verde area, we found a complex stratification with dust covering the altitude range below 2 km and tropical biomass burning layers aloft. We show that the aerosol type of individual aerosol layers can be classified based on depolarization and lidar ratios and, in addition, on in situ measured Ångström exponents of absorption åap. The dust layers had a geometrical depth of 1.3 ± 0.4 km and showed a median åap of 3.95. The median effective diameter Deff was 2.5 μm and the dust layers over Cape Verde yielded clear signals of aging: large particles were depleted due to gravitational settling and the accumulation mode diameter was shifted towards larger sizes as a result of coagulation. The tropical biomass layers had a depth of 2.0 ± 1.1 km and were characterized by a median åap of 1.34. They always contained a certain amount of large dust particles and showed a median Deff of 1.1 μm and a fine mode Deff,fine of 0.33. The dust and biomass burning layers had a median aerosol optical depth (AOD) of 0.23 and 0.09, respectively. The median contributions of the dust and biomass burning layers to the AOD of the total atmospheric column below 10 km were 75 and 37%, respectively. We present the properties of

  10. Collection strategy, inner morphology, and size distribution of dust particles in ASDEX Upgrade

    SciTech Connect

    M. Balden; N. Endstrasser; P. W. Humrickhouse; V. Rohde; M. Rasinski; U. von Toussaint; S. Elgeti; R. Neu

    2014-04-01

    The dust collection and analysis strategy in ASDEX Upgrade (AUG) is described. During five consecutive operation campaigns (2007–2011), Si collectors were installed, which were supported by filtered vacuum sampling and collection with adhesive tapes in 2009. The outer and inner morphology (e.g. shape) and elemental composition of the collected particles were analysed by scanning electron microscopy. The majority of the ~50?000 analysed particles on the Si collectors of campaign 2009 contain tungsten—the plasma-facing material in AUG—and show basically two different types of outer appearance: spheroids and irregularly shaped particles. By far most of the W-dominated spheroids consist of a solid W core, i.e. solidified W droplets. A part of these particles is coated with a low-Z material; a process that seems to happen presumably in the far scrape-off layer plasma. In addition, some conglomerates of B, C and W appear as spherical particles after their contact with plasma. By far most of the particles classified as B-, C- and W-dominated irregularly shaped particles consist of the same conglomerate with varying fraction of embedded W in the B–C matrix and some porosity, which can exceed 50%. The fragile structures of many conglomerates confirm the absence of intensive plasma contact. Both the ablation and mobilization of conglomerate material and the production of W droplets are proposed to be triggered by arcing. The size distribution of each dust particle class is best described by a log-normal distribution allowing an extrapolation of the dust volume and surface area. The maximum in this distribution is observed above the resolution limit of 0.28 µm only for the W-dominated spheroids, at around 1 µm. The amount of W-containing dust is extrapolated to be less than 300 mg on the horizontal areas of AUG.

  11. Introducing a New Stratospheric Dust-Collecting System with Potential Use for Upper Atmospheric Microbiology Investigations

    PubMed Central

    Rietmeijer, Frans J.M.; Rotundi, Alessandra; Ferrari, Marco

    2014-01-01

    Abstract The stratosphere is a known host to terrestrial microbes of most major biological lineages, but it is also host to incoming meteoric dust. Our goal is to (1) introduce DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval), an active collector for the nondestructive collection of nano- to micrometer particles in the stratosphere between 30 and 40 km altitude, and (2) demonstrate that even a single particle can be collected free of resident atmospheric and laboratory contaminant particles. DUSTER improves the pervasive and persistent contamination problem in the field of aerobiology research. Here, we demonstrate the collector's advances by the identification of a (terrestrial) spore particle found among a population of nanometer-scale inorganic meteoric particles. This was possible because the size, shape, morphology, and chemical composition of each particle can be determined while still on the collector surface. Particles can be removed from DUSTER for specific laboratory analyses. So far, DUSTER has not been fitted for aerobiological purposes; that is, no attempts were made to sterilize the collector other than with isopropyl alcohol. Its design and laboratory protocols, however, allow adjustments to dedicated aerobiological sampling opportunities. Key Words: Aerobiology—Upper stratosphere—Dust collector—Single particles—Sampling. Astrobiology 14, 694–705. PMID:25046407

  12. Airborne spectrophotometry of SN 1987A from 1.7 to 12.6 microns - Time history of the dust continuum and line emission

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; Rank, David M.; Bregman, Jesse D.; Witteborn, Fred C.; Tielens, A. G. G. M.; Cohen, Martin; Pinto, Philip A.; Axelrod, Timothy S.

    1993-01-01

    Spectrophotometric observations of SN 1987A from the Kuiper Airborne Observatory are presented for five epochs at 60, 260, 415, 615, and 775 days after the explosion. The low-resolution (lambda/Delta lambda = 50-100) spectra of SN 1987A are combined with data from other wavelengths to model the continuum, subtract the continuum from the spectra to determine line strengths and reveal molecular bands, separate the atomic continuum radiation from the dust continuum, and derive constraints on the grain temperatures and optical depths. A scenario for the evolution of SN 1987A and that of the ejecta from which it arises is obtained on the basis of the analysis of the continuum emission.

  13. Cosmic dust collection with a sub-satellite tethered to a space station

    NASA Technical Reports Server (NTRS)

    Corso, G. J.

    1986-01-01

    The number concentration and density of 1 micron and submicron sized grains in interplanetary space, as well as their relation to the larger zodical dust particles, and the importance of the Beta meteoroid phenomenon are currently being questioned. The best approach to collecting large numbers of intact micron and submicron sized cosmic dust particles in real time while avoiding terrestrial and man made contamination would be to employ a tethered subsatellite from a space station down into the Earth's atmosphere. Such a subsatellite tied to the space shuttle by a 100 km long tether is being developed. It is also possible that a permanent space station would allow the use of a tether even longer that 100 km. It should be noted that the same tethered collectors could also be employed to study the composition and flux of man made Earth orbiting debris in any direction within 100 km or so of the space station.

  14. Cosmic dust collection with a sub satellite tethered to a Space Station

    NASA Technical Reports Server (NTRS)

    Corso, George J.

    1987-01-01

    The number concentration and density of 1 micron and submicron sized grains in interplanetary space, as well as their relation to the larger zodical dust particles, and the importance of the beta meteoroid phenomenon are currently being questioned. The best approach to collecting large numbers of intact micron and submicron sized cosmic dust particles in real time while avoiding terrestrial and man made contamination would be to employ a tethered subsatellite from a space station down into the earth's atmosphere. Such a subsatellite tied to the space shuttle by a 100 km long tether is being developed. It is also possible that a permanent space station would allow the use of a tether even longer than 100 km. It should be noted that the same tethered collectors could also be employed to study the composition and flux of man made earth orbiting debris in any direction within 100 km or so of the space station.

  15. Aspergillus, Penicillium and Talaromyces isolated from house dust samples collected around the world.

    PubMed

    Visagie, C M; Hirooka, Y; Tanney, J B; Whitfield, E; Mwange, K; Meijer, M; Amend, A S; Seifert, K A; Samson, R A

    2014-06-01

    As part of a worldwide survey of the indoor mycobiota, dust was collected from nine countries. Analyses of dust samples included the culture-dependent dilution-to-extinction method and the culture-independent 454-pyrosequencing. Of the 7 904 isolates, 2 717 isolates were identified as belonging to Aspergillus, Penicillium and Talaromyces. The aim of this study was to identify isolates to species level and describe the new species found. Secondly, we wanted to create a reliable reference sequence database to be used for next-generation sequencing projects. Isolates represented 59 Aspergillus species, including eight undescribed species, 49 Penicillium species of which seven were undescribed and 18 Talaromyces species including three described here as new. In total, 568 ITS barcodes were generated, and 391 β-tubulin and 507 calmodulin sequences, which serve as alternative identification markers. PMID:25492981

  16. Aspergillus, Penicillium and Talaromyces isolated from house dust samples collected around the world

    PubMed Central

    Visagie, C.M.; Hirooka, Y.; Tanney, J.B.; Whitfield, E.; Mwange, K.; Meijer, M.; Amend, A.S.; Seifert, K.A.; Samson, R.A.

    2014-01-01

    As part of a worldwide survey of the indoor mycobiota, dust was collected from nine countries. Analyses of dust samples included the culture-dependent dilution-to-extinction method and the culture-independent 454-pyrosequencing. Of the 7 904 isolates, 2 717 isolates were identified as belonging to Aspergillus, Penicillium and Talaromyces. The aim of this study was to identify isolates to species level and describe the new species found. Secondly, we wanted to create a reliable reference sequence database to be used for next-generation sequencing projects. Isolates represented 59 Aspergillus species, including eight undescribed species, 49 Penicillium species of which seven were undescribed and 18 Talaromyces species including three described here as new. In total, 568 ITS barcodes were generated, and 391 β-tubulin and 507 calmodulin sequences, which serve as alternative identification markers. PMID:25492981

  17. Aspergillus, Penicillium and Talaromyces isolated from house dust samples collected around the world.

    PubMed

    Visagie, C M; Hirooka, Y; Tanney, J B; Whitfield, E; Mwange, K; Meijer, M; Amend, A S; Seifert, K A; Samson, R A

    2014-06-01

    As part of a worldwide survey of the indoor mycobiota, dust was collected from nine countries. Analyses of dust samples included the culture-dependent dilution-to-extinction method and the culture-independent 454-pyrosequencing. Of the 7 904 isolates, 2 717 isolates were identified as belonging to Aspergillus, Penicillium and Talaromyces. The aim of this study was to identify isolates to species level and describe the new species found. Secondly, we wanted to create a reliable reference sequence database to be used for next-generation sequencing projects. Isolates represented 59 Aspergillus species, including eight undescribed species, 49 Penicillium species of which seven were undescribed and 18 Talaromyces species including three described here as new. In total, 568 ITS barcodes were generated, and 391 β-tubulin and 507 calmodulin sequences, which serve as alternative identification markers.

  18. Improving plant competitiveness through conveyor dust control technologies

    SciTech Connect

    Goldbeck, L.J.

    1997-09-01

    In the past, three different approaches--containment, suppression, and collection--have been used to control dust arising at conveyor load zones. Dust containment consists of those mechanical systems employed to keep material inside the transfer point with the main material body. Dust suppression systems increase the mass of suspended dust particles, allowing them to fall from the airstream. Dust collection is the mechanical capture and return of airborne material after it becomes airborne from the main material body. Previously, these three approaches have always been seen as separate entities, offered by separate organizations competing in the marketplace. Each system claimed its own technology was the best solution, providing the most effective, most cost-efficient, most maintenance-free answer to fugitive material. These three technologies are evaluated.

  19. [Chemical characteristics in airborne particulate matter (PM10) during a high pollution spring dust storm episode in Beijing, Tianjin and Zhangjiakou, China].

    PubMed

    Liu, Qing-Yang; Liu, Yan-Ju; Zhao, Qiang; Zhang, Ting-Ting; Zhang, Mei-Gen; Wang, Cun-Mei

    2014-08-01

    Atmospheric particulate matter (PM10) was collected at sampling locations of Beijing, Tianjin and Zhangjiakou from April 1st to May 24th, 2012. The mass concentration of PM10 and concentrations of ions, elemental carbon (EC) and organic carbon (OC) in PM10 were determined. The results showed that average mass concentration of PM10 were 233.82 microg x m(-3) for Beijing, 279.64 microg x (-3) for Tianjin and 238.13 microg x m(-3) for Zhangjiakou, respectively. Backward trajectories results confirmed dust storm events occurred from 27th to 29th April. The maximum daily mass concentrations of PM10 were 755.54 microg x m(-3) for Beijing, 831.32 microg x m(-3) for Tianjin and 582.82 microg x m(-3) for Zhangjiakou during the dust storm episodes, respectively. Water-soluble ions (Na+, NH4+, Ca2+, K+, F-, Cl-, NO3-, SO4(2-)), organic carbon (OC) and elemental carbon (EC) were major aerosol components during the dust storm episodes, and their concentrations were higher than non-dust storm days. In addition, dust storm caused increases in NO3-, SO4(2-) and enrichment of secondary organic carbon (SOC) concentration relative to OC, suggesting that chemical reaction processes involving gas-particle conversion occurred during the long-distance transport of aerosol particles. PMID:25338350

  20. [Chemical characteristics in airborne particulate matter (PM10) during a high pollution spring dust storm episode in Beijing, Tianjin and Zhangjiakou, China].

    PubMed

    Liu, Qing-Yang; Liu, Yan-Ju; Zhao, Qiang; Zhang, Ting-Ting; Zhang, Mei-Gen; Wang, Cun-Mei

    2014-08-01

    Atmospheric particulate matter (PM10) was collected at sampling locations of Beijing, Tianjin and Zhangjiakou from April 1st to May 24th, 2012. The mass concentration of PM10 and concentrations of ions, elemental carbon (EC) and organic carbon (OC) in PM10 were determined. The results showed that average mass concentration of PM10 were 233.82 microg x m(-3) for Beijing, 279.64 microg x (-3) for Tianjin and 238.13 microg x m(-3) for Zhangjiakou, respectively. Backward trajectories results confirmed dust storm events occurred from 27th to 29th April. The maximum daily mass concentrations of PM10 were 755.54 microg x m(-3) for Beijing, 831.32 microg x m(-3) for Tianjin and 582.82 microg x m(-3) for Zhangjiakou during the dust storm episodes, respectively. Water-soluble ions (Na+, NH4+, Ca2+, K+, F-, Cl-, NO3-, SO4(2-)), organic carbon (OC) and elemental carbon (EC) were major aerosol components during the dust storm episodes, and their concentrations were higher than non-dust storm days. In addition, dust storm caused increases in NO3-, SO4(2-) and enrichment of secondary organic carbon (SOC) concentration relative to OC, suggesting that chemical reaction processes involving gas-particle conversion occurred during the long-distance transport of aerosol particles.

  1. Characterization of Fine Airborne Particulate Collected in Tokyo and Major Atmospheric Emission Sources by Using Single Particle Measurement of SEM-EDX

    NASA Astrophysics Data System (ADS)

    Sato, K.; Iijima, A.; Furuta, N.

    2008-12-01

    In our long-term monitoring of size-classified Airborne Particulate Matter (APM) in Tokyo since 1995, it had been demonstrated that toxic elements such as As, Se, Cd, Sb and Pb were extremely enriched in fine APM (PM2.5). However, in that study, total sampled APM on a filter was digested with acids, and thus only averaged elemental composition in fine APM could be obtained. One of the effective methods to determine the origin of APM is single particle measurement by using SEM-EDX. By using characteristic shapes observed by SEM and marker elements contained in APM measured by EDX, detailed information for source identification can be obtained. In this study, fine APM (PM2.5) was collected at various locations such as roadside, diesel vehicle exhaust, a heavy oil combustion plant and a waste incineration plant as well as ambient atmosphere in Tokyo, and characteristics of fine particles that will be utilized for identification of emission sources are elucidated. Fine particles can be classified into 3 main characteristic shape groups; edge-shaped, cotton-like and spherical. Shape of particles collected in a heavy oil combustion plant and a waste incineration plant was mostly spherical, and these particles may be associated with thermal process. Diesel exhaust particles were predominantly cotton-like which may consist of coagulated nano-sized particles. Most of brake abrasion dusts were edge-shaped, which may be associated with mechanical abrasion of brake pads. In the elemental analysis of fine particles, high concentrations of Sb, Cu, Ti and Ba were detected in brake abrasion dusts. Since these elements are major constituents of brake pads, these can be used for marker elements of brake abrasion dusts. High concentration of C was detected in diesel exhaust particles and oil combustion particles, and thus C can be used for marker elements of their origin. Furthermore, high concentrations of C, Ca and K were detected in fly ash from a waste incineration plant, which

  2. Attempt at dust debris collection with stacked detectors (A0138-2)

    NASA Technical Reports Server (NTRS)

    Mandeville, J. C.

    1984-01-01

    The primary objective of this experiment is to investigate the feasibility of future missions of multilayer thin-film detectors acting as energy sorter to collect micrometeoroids, if not in their original shape, at least as fragments suitable for chemical analysis. It is expected that this kind of particle collector will help in solving one of the most puzzling topics in cosmic-dust studies: the mineralogical and chemical composition of the particles. This is a matter of great interest in the study of the origin and evolution of the solar system.

  3. Airborne Sunphotometer Measurements of Aerosol Optical Depth and Columnar Water Vapor During the Puerto Rico Dust Experiment, and Comparison with Land, Aircraft, and Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Livingston, John M.; Russell, Philip B.; Reid, Jeffrey; Redemann, Jens; Schmid, Beat; Allen, Duane A.; Torres, Omar; Levy, Robert C.; Remer, Lorraine A.; Holben, Brent N.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    Analyses of aerosol optical depth (AOD) and columnar water vapor (CWV) measurements obtained with the six-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) mounted on a twin-engine aircraft during the summer 2000 Puerto Rico Dust Experiment are presented. In general, aerosol extinction values calculated from AATS-6 AOD measurements acquired during aircraft profiles up to 5 km ASL reproduce the vertical structure measured by coincident aircraft in-situ measurements of total aerosol number and surface area concentration. Calculations show that the spectral dependence of AOD was small (mean Angstrom wavelength exponents of approximately 0.20) within three atmospheric layers defined as the total column beneath the top of each aircraft profile, the region beneath the trade wind inversion, and the region within the Saharan Air Layer (SAL) above the trade inversion. This spectral behavior is consistent with attenuation of incoming solar radiation by large dust particles or by dust plus sea salt. Values of CWV calculated from profile measurements by AATS-6 at 941.9 nm and from aircraft in-situ measurements by a chilled mirror dewpoint hygrometer agree to within approximately 4% (0.13 g/sq cm). AATS-6 AOD values measured on the ground at Roosevelt Roads Naval Air Station and during low altitude aircraft runs over the adjacent Cabras Island aerosol/radiation ground site agree to within 0.004 to 0.030 with coincident data obtained with an AERONET Sun/sky Cimel radiometer located at Cabras Island. For the same observation times, AERONET retrievals of CWV exceed AATS-6 values by a mean of 0.74 g/sq cm (approximately 21 %) for the 2.9-3.9 g/sq cm measured by AATS-6. Comparison of AATS-6 aerosol extinction values obtained during four aircraft ascents over Cabras Island with corresponding values calculated from coincident aerosol backscatter measurements by a ground-based micro-pulse lidar (MPL-Net) located at Cabras yields a similar vertical structure above the trade

  4. Potential exposures to airborne and settled surface dust in residential areas of lower Manhattan following the collapse of the World Trade Center--New York City, November 4-December 11, 2001.

    PubMed

    2003-02-21

    Following the terrorist attacks of September 11, 2001, which destroyed the World Trade Center (WTC) in lower Manhattan, the New York City (NYC) Department of Health and Mental Hygiene (DOHMH) and the Agency for Toxic Substances and Disease Registry (ATSDR), with assistance from the U.S. Public Health Service (PHS) Commissioned Corps Readiness Force and the WTC Environmental Assessment Working Group, assessed the composition of outdoor and indoor settled surface and airborne dust in residential areas around the WTC and in comparison areas. This report summarizes the results of the investigation, which found 1) similar levels of airborne total fibers in lower and in upper Manhattan, 2) greater percentage levels of synthetic vitreous fibers (SVF) and mineral components of concrete and building wallboard in settled dust of residential areas in lower Manhattan than in upper Manhattan, and 3) low levels of asbestos in some settled surface dust in lower Manhattan residential areas. Based in part on the results of this investigation, the U.S. Environmental Protection Agency (EPA) is cleaning and sampling residential areas as requested by lower Manhattan residents. In addition, to assess any short- or long-term health effects of smoke, dust, and airborne substances around the WTC site, DOHMH and ATSDR are developing a registry that will track the health of persons who were most highly exposed to these materials.

  5. Integration for Airborne Dust Prediction Systems and Vegetation Phenology to Track Pollen for Asthma Alerts in Public Health Decision Support Systems

    NASA Technical Reports Server (NTRS)

    Luvall, J. C.; Sprigg, W. A.; Nickovic, S.; Huete, A.; Budge, A.; Flowers, L.

    2008-01-01

    The objective of the program is to assess the feasibility of combining a dust transport model with MODIS derived phenology to study pollen transport for integration with a public health decision support system. The use of pollen information has specifically be identified as a critical need by the New Mexico State Health department for inclusion in the Environmental Public Health Tracking (EPHT) program. Material and methods: Pollen can be transported great distances. Local observations of plan phenology may be consistent with the timing and source of pollen collected by pollen sampling instruments. The Dust REgional Atmospheric Model (DREAM) is an integrated modeling system designed to accurately describe the dust cycle in the atmosphere. The dust modules of the entire system incorporate the state of the art parameterization of all the major phases of the atmospheric dust life such as production, diffusion, advection, and removal. These modules also include effects of the particles size distribution on aerosol dispersion. The model was modified to use pollen sources instead of dust. Pollen release was estimated based on satellite-derived phenology of key plan species and vegetation communities. The MODIS surface reflectance product (MOD09) provided information on the start of the plant growing season, growth stage, and pollen release. The resulting deterministic model is useful for predicting and simulating pollen emission and downwind concentration to study details of phenology and meteorology and their dependencies. The proposed linkage in this project provided critical information on the location timing and modeled transport of pollen directly to the EPHT> This information is useful to support the centers for disease control and prevention (CDC)'s National EPHT and the state of New Mexico environmental public health decision support for asthma and allergies alerts.

  6. House dust in seven Danish offices

    NASA Astrophysics Data System (ADS)

    Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

    Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000-160.000 CFU g -1 microorganisms and 71.000-90.000 CFU g -1 microfungi. The content of culturable microfungi was 65-123 CFU 30 g -1 dust. The content of endotoxins ranged from 5.06-7.24 EU g -1 (1.45 ng g -1 to 1.01 ng g -1). Allergens (ng g -1) were from 147-159 (Mite), 395-746 (dog) and 103-330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8-9.8 mg g -1. The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml -1. The water content was 2% (WGT) and the organic fraction 33%. 6.5-5.9% (dry) was water soluble. The fiber content was less than 0.2-1.5% (WGT) and the desorbable VOCs was 176-319 μg g -1. Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001-1 mm and the average specific density was 1.0 g m -3. The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26-0.75 mg m -3 in average contained 300-170 CFU m -3. The organic fraction was from 55-70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is

  7. Introducing a new stratospheric dust-collecting system with potential use for upper atmospheric microbiology investigations.

    PubMed

    Della Corte, Vincenzo; Rietmeijer, Frans J M; Rotundi, Alessandra; Ferrari, Marco

    2014-08-01

    The stratosphere is a known host to terrestrial microbes of most major biological lineages, but it is also host to incoming meteoric dust. Our goal is to (1) introduce DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval), an active collector for the nondestructive collection of nano- to micrometer particles in the stratosphere between 30 and 40 km altitude, and (2) demonstrate that even a single particle can be collected free of resident atmospheric and laboratory contaminant particles. DUSTER improves the pervasive and persistent contamination problem in the field of aerobiology research. Here, we demonstrate the collector's advances by the identification of a (terrestrial) spore particle found among a population of nanometer-scale inorganic meteoric particles. This was possible because the size, shape, morphology, and chemical composition of each particle can be determined while still on the collector surface. Particles can be removed from DUSTER for specific laboratory analyses. So far, DUSTER has not been fitted for aerobiological purposes; that is, no attempts were made to sterilize the collector other than with isopropyl alcohol. Its design and laboratory protocols, however, allow adjustments to dedicated aerobiological sampling opportunities.

  8. Introducing a new stratospheric dust-collecting system with potential use for upper atmospheric microbiology investigations.

    PubMed

    Della Corte, Vincenzo; Rietmeijer, Frans J M; Rotundi, Alessandra; Ferrari, Marco

    2014-08-01

    The stratosphere is a known host to terrestrial microbes of most major biological lineages, but it is also host to incoming meteoric dust. Our goal is to (1) introduce DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval), an active collector for the nondestructive collection of nano- to micrometer particles in the stratosphere between 30 and 40 km altitude, and (2) demonstrate that even a single particle can be collected free of resident atmospheric and laboratory contaminant particles. DUSTER improves the pervasive and persistent contamination problem in the field of aerobiology research. Here, we demonstrate the collector's advances by the identification of a (terrestrial) spore particle found among a population of nanometer-scale inorganic meteoric particles. This was possible because the size, shape, morphology, and chemical composition of each particle can be determined while still on the collector surface. Particles can be removed from DUSTER for specific laboratory analyses. So far, DUSTER has not been fitted for aerobiological purposes; that is, no attempts were made to sterilize the collector other than with isopropyl alcohol. Its design and laboratory protocols, however, allow adjustments to dedicated aerobiological sampling opportunities. PMID:25046407

  9. Coal miners' mortality in relaton to radiological category, lung function and exposure to airborne dust. Final report

    SciTech Connect

    Miller, B.G.; Jacobsen, M.; Steele, R.C.

    1981-06-01

    This report describes mortality among 29,553 British coal miners. They represent 93.5% of 31,611 men who were surveyed radiologically at 24 coal mines in the period 1953 through 1958. The main aim of the work was to consider risks of death attributed to various underlying causes, as recorded on death certificates, in relation to radiological signs of pneumoconiosis, measures of lung function, and exposure to respirable coal mine dust.

  10. Preliminary assessment of an economical fugitive road dust sampler for the collection of bulk samples for geochemical analysis.

    PubMed

    Witt, Emitt C; Wronkiewicz, David J; Shi, Honglan

    2013-01-01

    Fugitive road dust collection for chemical analysis and interpretation has been limited by the quantity and representativeness of samples. Traditional methods of fugitive dust collection generally focus on point-collections that limit data interpretation to a small area or require the investigator to make gross assumptions about the origin of the sample collected. These collection methods often produce a limited quantity of sample that may hinder efforts to characterize the samples by multiple geochemical techniques, preserve a reference archive, and provide a spatially integrated characterization of the road dust health hazard. To achieve a "better sampling" for fugitive road dust studies, a cyclonic fugitive dust (CFD) sampler was constructed and tested. Through repeated and identical sample collection routes at two collection heights (50.8 and 88.9 cm above the road surface), the products of the CFD sampler were characterized using particle size and chemical analysis. The average particle size collected by the cyclone was 17.9 μm, whereas particles collected by a secondary filter were 0.625 μm. No significant difference was observed between the two sample heights tested and duplicates collected at the same height; however, greater sample quantity was achieved at 50.8 cm above the road surface than at 88.9 cm. The cyclone effectively removed 94% of the particles >1 μm, which substantially reduced the loading on the secondary filter used to collect the finer particles; therefore, suction is maintained for longer periods of time, allowing for an average sample collection rate of about 2 g mi.

  11. Exposure to airborne allergens: a review of sampling methods.

    PubMed

    Renström, Anne

    2002-10-01

    A number of methods are used to assess exposure to high-molecular weight allergens. In the occupational setting, airborne dust is often collected on filters using pumps, the filters are eluted and allergen content in the eluate analysed using immunoassays. Collecting inhalable dust using person-carried pumps may be considered the gold standard. Other allergen sampling methods are available. Recently, a method that collects nasally inhaled dust on adhesive surfaces within nasal samplers has been developed. Allergen content can be analysed in eluates using sensitive enzyme immunoassays, or allergen-bearing particles can be immunostained using antibodies, and studied under the microscope. Settling airborne dust can be collected in petri dishes, a cheap and simple method that has been utilised in large-scale exposure studies. Collection of reservoir dust from surfaces using vacuum cleaners with a dust collector is commonly used to measure pet or mite allergens in homes. The sampling methods differ in properties and relevance to personal allergen exposure. Since methods for all steps from sampling to analysis differ between laboratories, determining occupational exposure limits for protein allergens is today unfeasible. A general standardisation of methods is needed.

  12. Airborne detection and quantification of swine influenza a virus in air samples collected inside, outside and downwind from swine barns.

    PubMed

    Corzo, Cesar A; Culhane, Marie; Dee, Scott; Morrison, Robert B; Torremorell, Montserrat

    2013-01-01

    Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m³ of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m³ of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m³. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions.

  13. Airborne Detection and Quantification of Swine Influenza A Virus in Air Samples Collected Inside, Outside and Downwind from Swine Barns

    PubMed Central

    Corzo, Cesar A.; Culhane, Marie; Dee, Scott; Morrison, Robert B.; Torremorell, Montserrat

    2013-01-01

    Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m3 of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m3 of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m3. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions. PMID:23951164

  14. Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India.

    NASA Astrophysics Data System (ADS)

    Sharma, Disha; Kulshrestha, Umesh

    Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India. The Critical Load approach alongwith integrated assessment models has been used in the European nations for policy formations to reduce acidic emissions. This unique approach was applied to assess the of vulnerability of natural systems to the present day atmospheric pollution scenario. The calculated values of critical loads of sulphur ( 225 - 275 eq/ha/yr) and nitrogen (298 - 303 eq/ha/yr), for the soil system in Delhi, were calculated with respect to Anjan grass, Hibiscus and Black siris. The present loads of sulphur (PL(S) = 26.40 eq/ha/yr) and nitrogen (PL(N) = 36.51 eq/ha/yr) were found to be much lower than their critical loads without posing any danger of atmospheric acidic deposition on the soil systems. The study indicated that the system is still protective due to high pH of soil. The nature of buffering capability of calcium derived from soil dust can be considered as a natural tool to combat acidification in the Indian region. The results showed that the pollution status in Delhi is still within the safe limits. However, at the pace at which the city is growing, it is likely that in coming decades, it may exceed these critical values. In order to set deposition limits and avoid adverse effects of acidic deposition this approach can be applied in India too. Such approach is very useful, not only in abating pollution but also in devising means of cost optimal emission abatement strategies.

  15. Characterisation of nano- and micron-sized airborne and collected subway particles, a multi-analytical approach.

    PubMed

    Midander, Klara; Elihn, Karine; Wallén, Anna; Belova, Lyuba; Karlsson, Anna-Karin Borg; Wallinder, Inger Odnevall

    2012-06-15

    Continuous daily measurements of airborne particles were conducted during specific periods at an underground platform within the subway system of the city center of Stockholm, Sweden. Main emphasis was placed on number concentration, particle size distribution, soot content (analyzed as elemental and black carbon) and surface area concentration. Conventional measurements of mass concentrations were conducted in parallel as well as analysis of particle morphology, bulk- and surface composition. In addition, the presence of volatile and semi volatile organic compounds within freshly collected particle fractions of PM(10) and PM(2.5) were investigated and grouped according to functional groups. Similar periodic measurements were conducted at street level for comparison. The investigation clearly demonstrates a large dominance in number concentration of airborne nano-sized particles compared to coarse particles in the subway. Out of a mean particle number concentration of 12000 particles/cm(3) (7500 to 20000 particles/cm(3)), only 190 particles/cm(3) were larger than 250 nm. Soot particles from diesel exhaust, and metal-containing particles, primarily iron, were observed in the subway aerosol. Unique measurements on freshly collected subway particle size fractions of PM(10) and PM(2.5) identified several volatile and semi-volatile organic compounds, the presence of carcinogenic aromatic compounds and traces of flame retardants. This interdisciplinary and multi-analytical investigation aims to provide an improved understanding of reported adverse health effects induced by subway aerosols. PMID:22551935

  16. Typology of dust particles collected by the COSIMA mass spectrometer in the inner coma of 67P/Churyumov Gerasimenko

    NASA Astrophysics Data System (ADS)

    Langevin, Y.; Hilchenbach, M.; Ligier, N.; Merouane, S.; Hornung, K.; Engrand, C.; Schulz, R.; Kissel, J.; Rynö, J.; Eng, P.

    2016-06-01

    The COSIMA mass spectrometer on board the ROSETTA orbiter has collected dust in the near coma of comet 67P/Churyumov-Gerasimenko since August 11, 2014. The collected dust particles are identified by taking images with a microscope (COSISCOPE) under grazing incidence illumination before and after exposure of the target to cometary dust. More than 10,000 dust particles >14 μm in size collected from August 11, 2014 to April 3, 2015 have been detected on three distinct target assemblies, including ˜500 dust particles with sizes ranging from 50 to more than 500 μm, that can be resolved by COSISCOPE (pixel size 14 μm). During this period, the heliocentric distance decreased from 3.5 AU to less than 2 AU. The collection efficiency on targets covered with "metal black" has been very high, due to the low relative velocity of incoming dust. Therefore, the COSISCOPE observations provide the first optical characterization of an unbiased sample of particles collected in the inner coma of a comet. The typology of particles >100 μm in size is dominated by clusters with a wide range of structure and strength, most originating from the disruption of large aggregates (>1 mm in size) shortly before collection. A generic relationship between these clusters and IDPs/Antarctic meteorites is likely in the framework of accretion models. About 15% of particles larger than 100 μm are compact particles with two likely contributions, one being linked to clusters and another leaving the cometary nucleus as single compact particles.

  17. Analysis of volatiles present in interplanetary dust and stratospheric particles collected on large area collectors

    NASA Technical Reports Server (NTRS)

    Hartmetz, C. P.; Gibson, E. K., Jr.; Blanford, G. E.

    1991-01-01

    Results are presented from an analysis of six chondritic interplanetary dust particles (IDPs) and 22 other stratospheric particles collected on large-area collector, carried out in order to obtain information on the nature, distribution, and form of volatiles in IDPs. A laser microprobe/mass spectrometer (LMMS) was used to extract volatile elements and molecules from particles larger than 10 microns, and an improved hexane rinsing technique was developed for the removal of contaminants. Results show that, because of contamination from silicone oil, freon, and hexane, most of the LMMS signal from IDPs can be interpreted as arising from contamination. Therefore, a species was not considered indigenous unless the signal was an order of magnitude greater in abundance than that released from a pure contaminant coated on gold.

  18. Repetitive Immunoassay with a Surface Acoustic Wave Device and a Highly Stable Protein Monolayer for On-Site Monitoring of Airborne Dust Mite Allergens.

    PubMed

    Toma, Koji; Miki, Daisuke; Kishikawa, Chisato; Yoshimura, Naoyuki; Miyajima, Kumiko; Arakawa, Takahiro; Yatsuda, Hiromi; Mitsubayashi, Kohji

    2015-10-20

    This work describes a sensor to be incorporated into the on-site monitoring system of airborne house dust mite (HDM) allergens. A surface acoustic wave (SAW) device was combined with self-assembled monolayers of a highly stable antibody capture protein on the SAW surface that have high resistance to pH change. A sandwich assay was used to measure a HDM allergen, Der f 1 derived from Dermatophagoides farinae. Capture antibodies were cross-linked to a protein G based capture layer (ORLA85) on the sensor surface, thereby only Der f 1 and detection antibodies were regenerated by changing pH, resulting in fast repetition of the measurement. The sensor was characterized through 10 repetitive measurements of Der f 1, which demonstrated high reproducibility of the sensor with the coefficient of variation of 5.6%. The limit of detection (LOD) of the sensor was 6.1 ng·mL(-1), encompassing the standard (20 ng·mL(-1)) set by the World Health Organization. Negligible sensor outputs were observed for five different major allergens including other HDM allergens which tend to have cross-reactivity to Der f 1 and their mixtures with Der f 1. Finally, the sensor lifetime was evaluated by conducting three measurements per day, and the sensor output did not substantially change for 4 days. These characteristics make the SAW immunosensor a promising candidate for incorporation into on-site allergen monitoring systems.

  19. Human occupancy as a source of indoor airborne bacteria.

    PubMed

    Hospodsky, Denina; Qian, Jing; Nazaroff, William W; Yamamoto, Naomichi; Bibby, Kyle; Rismani-Yazdi, Hamid; Peccia, Jordan

    2012-01-01

    Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM(10) and PM(2.5) size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM(10). On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments.

  20. Volatile organic compounds in an urban airborne environment adjacent to a municipal incinerator, waste collection centre and sewage treatment plant

    NASA Astrophysics Data System (ADS)

    Leach, J.; Blanch, A.; Bianchi, A. C.

    The occurrence and temporal distribution of airborne volatile organic compounds (VOC) at nine closely grouped locations in a suburban environment on the edge of the coastline of the Southampton Water estuary, located on the coastline of central southern England, was studied over six monthly periods spanning 1996-1997. The sampling sites circumscribed a juxtaposed municipal incinerator, waste collection and processing centre and sewage treatment plant. Three sets of airborne samples being taken before and after the closure of the municipal incinerator. VOC with volatilities of low to medium polarity ranging broadly from those of n-butane to n-octadecane were the major focus of interest. Over 100 individual compounds were routinely found in localised samples taken during the period of study. The types and concentrations of VOC identified partly reflect the imprint of the various waste processing operations on atmospheric VOC within the local environment. The most abundant VOC classes consisted of aromatic, chlorinated and organosulphide compounds, with smaller proportions of alkanes, alkenes and cycloalkane compounds. Compounds produced by sewage-processing and waste management operations, including volatile organosulphides and various oxygenated compounds, may occasionally exceed olfactory detection thresholds and represent a source of potential odour complaints in the local urban environment.

  1. Natural and anthropogenic radionuclides in airborne particulate samples collected in Barcelona (Spain).

    PubMed

    Vallés, I; Camacho, A; Ortega, X; Serrano, I; Blázquez, S; Pérez, S

    2009-02-01

    Results for naturally occurring (7)Be, (210)Pb, (40)K, (214)Bi, (214)Pb, (212)Pb, (228)Ac and (208)Tl and anthropogenic (137)Cs in airborne particulate matter in the Barcelona area during the period from January 2001 to December 2005 are presented and discussed. The (212)Pb and (208)Tl, (214)Bi and (214)Pb, (7)Be and (210)Pb radionuclide levels showed a significant correlation with each other, with correlation coefficients of 0.99, 0.78 and 0.69, respectively, suggesting similar origin/behaviour of these radionuclides in the air. Caessium-137 and Potassium-40 were transported to the air as resuspended particle from the soil. The (7)Be and (210)Pb concentrations showed similar seasonal variations, with a tendency for maximum concentrations during the summer months. An inverse relationship was observed between the (7)Be, (210)Pb, (40)K and (137)Cs concentrations and weekly rainfall, indicating washout of atmospheric aerosols carrying these radionuclides.

  2. Predictors of airborne endotoxin concentrations in inner city homes.

    PubMed

    Mazique, D; Diette, G B; Breysse, P N; Matsui, E C; McCormack, M C; Curtin-Brosnan, J; Williams, D L; Peng, R D; Hansel, N N

    2011-05-01

    Few studies have assessed in home factors which contribute to airborne endotoxin concentrations. In 85 inner city Baltimore homes, we found no significant correlation between settled dust and airborne endotoxin concentrations. Certain household activities and characteristics, including frequency of dusting, air conditioner use and type of flooring, explained 36-42% of the variability of airborne concentrations. Measurements of both airborne and settled dust endotoxin concentrations may be needed to fully characterize domestic exposure in epidemiologic investigations. PMID:21429483

  3. Waste Workers’ Exposure to Airborne Fungal and Bacterial Species in the Truck Cab and During Waste Collection

    PubMed Central

    Madsen, Anne Mette; Alwan, Taif; Ørberg, Anders; Uhrbrand, Katrine; Jørgensen, Marie Birk

    2016-01-01

    A large number of people work with garbage collection, and exposure to microorganisms is considered an occupational health problem. However, knowledge on microbial exposure at species level is limited. The aim of the study was to achieve knowledge on waste collectors’ exposure to airborne inhalable fungal and bacterial species during waste collection with focus on the transport of airborne microorganisms into the truck cab. Airborne microorganisms were collected with samplers mounted in the truck cab, on the workers’ clothes, and outdoors. Fungal and bacterial species were quantified and identified. The study showed that the workers were exposed to between 112 and 4.8×104 bacteria m−3 air and 326 and 4.6×104 fungi m−3 air. The personal exposures to bacteria and fungi were significantly higher than the concentrations measured in the truck cabs and in the outdoor references. On average, the fungal and bacterial concentrations in truck cabs were 111 and 7.7 times higher than outdoor reference measurements. In total, 23 fungal and 38 bacterial species were found and identified. Most fungal species belonged to the genus Penicillium and in total 11 Penicillium species were found. Identical fungal species were often found both in a personal sample and in the same person’s truck cab, but concentrations were on average 27 times higher in personal samples. Concentrations of fungal and bacterial species found only in the personal samples were lower than concentrations of species also found in truck cabs. Skin-related bacteria constituted a large fraction of bacterial isolates found in personal and truck cab samples. In total, six Staphylococcus species were found. In outdoor samples, no skin-related bacteria were found. On average, concentrations of bacterial species found both in the truck cab and personal samples were 77 times higher in personal samples than in truck cab samples. In conclusion, high concentrations of fungi were found in truck cabs, but the

  4. Airborne and Ground-Based Platforms for Data Collection in Small Vineyards: Examples from the UK and Switzerland

    NASA Astrophysics Data System (ADS)

    Green, David R.; Gómez, Cristina; Fahrentrapp, Johannes

    2015-04-01

    This paper presents an overview of some of the low-cost ground and airborne platforms and technologies now becoming available for data collection in small area vineyards. Low-cost UAV or UAS platforms and cameras are now widely available as the means to collect both vertical and oblique aerial still photography and airborne videography in vineyards. Examples of small aerial platforms include the AR Parrot Drone, the DJI Phantom (1 and 2), and 3D Robotics IRIS+. Both fixed-wing and rotary wings platforms offer numerous advantages for aerial image acquisition including the freedom to obtain high resolution imagery at any time required. Imagery captured can be stored on mobile devices such as an Apple iPad and shared, written directly to a memory stick or card, or saved to the Cloud. The imagery can either be visually interpreted or subjected to semi-automated analysis using digital image processing (DIP) software to extract information about vine status or the vineyard environment. At the ground-level, a radio-controlled 'rugged' model 4x4 vehicle can also be used as a mobile platform to carry a number of sensors (e.g. a Go-Pro camera) around a vineyard, thereby facilitating quick and easy field data collection from both within the vine canopy and rows. For the small vineyard owner/manager with limited financial resources, this technology has a number of distinct advantages to aid in vineyard management practices: it is relatively cheap to purchase; requires a short learning-curve to use and to master; can make use of autonomous ground control units for repetitive coverage enabling reliable monitoring; and information can easily be analysed and integrated within a GIS with minimal expertise. In addition, these platforms make widespread use of familiar and everyday, off-the-shelf technologies such as WiFi, Go-Pro cameras, Cloud computing, and smartphones or tablets as the control interface, all with a large and well established end-user support base. Whilst there are

  5. Characterization of sintering dust collected in the various fields of the electrostatic precipitator.

    PubMed

    Lanzerstorfer, Christof; Steiner, Dominik

    2016-01-01

    Sinter plant off-gas is usually de-dusted by electrostatic precipitators. Compliance with the dust emission limits is often difficult because of the high specific resistivity of the emitted dust. Mechanical properties of the dust are also relevant for the electrostatic precipitator design. Dust samples from the four consecutive electrostatic precipitator fields were characterized in this study. Most measured parameters showed a considerable variation in the various dust samples. The particle size of the dust as well as its bulk density continuously decreased from the first field to the fourth field. The flowability of the dusts was generally bad and decreased from the first to the last field. In contrast, the wall friction angles with structural steel were quite constant at approximately 30°. The Fe content was lower in the dust from the last two fields while the concentration of K, Na, Cl(-) and [Formula: see text] was significantly higher. At the same time the particle density was lower. The maximum specific dust resistivity for the first field and second field dust was approximately 3 × 10(11) Ω cm and no signs for the occurrence of back corona were detected. For the dusts from the last two fields the maximum value was approximately 2 × 10(12) Ω cm. Back corona was observed in the temperature range from 120°C to 210°C. In this area the dust resistivity values were higher than 4 × 10(11) Ω cm.

  6. Pyrethroid Pesticides and Their Metabolites in Vacuum Cleaner Dust Collected from Homes and Day-Care Centers

    EPA Science Inventory

    The purpose of this study was to quantify the concentrations of 13 selected pyrethroid pesticides and their degradation products in samples of indoor dust that had been collected in vacuum cleaner bags during the Children's Total Exposure to Persistent Pesticides and Other Persis...

  7. Impaction onto a Glass Slide or Agar versus Impingement into a Liquid for the Collection and Recovery of Airborne Microorganisms

    PubMed Central

    Juozaitis, Arvydas; Willeke, Klaus; Grinshpun, Sergey A.; Donnelly, Jean

    1994-01-01

    To study impaction versus impingement for the collection and recovery of viable airborne microorganisms, three new bioaerosol samplers have been designed and built. They differ from each other by the medium onto which the bioaerosol particles are collected (glass, agar, and liquid) but have the same inlet and collection geometries and the same sampling flow rate. The bioaerosol concentrations recorded by three different collection techniques have been compared with each other: impaction onto a glass slide, impaction onto an agar medium, and impingement into a liquid. It was found that the particle collection efficiency of agar slide impaction depends on the concentration of agar in the collection medium and on the sampling time, when samples are collected on a nonmoving agar slide. Impingement into a liquid showed anomalous behavior with respect to the sampling flow rate. Optimal sampling conditions in which all three new samplers exhibit the same overall sampling efficiency for nonbiological particles have been established. Inlet and collection efficiencies of about 100% have been achieved for all three devices at a sampling flow rate of 10 liters/min. The new agar slide impactor and the new impinger were then used to study the biological factors affecting the overall sampling efficiency. Laboratory experiments on the total recovery of a typical environmental microorganism, Pseudomonas fluorescens ATCC 13525, showed that both sampling methods, impaction and impingement, provided essentially the same total recovery when relatively nonstressed microorganisms were sampled under optimal sampling conditions. Comparison tests of the newly developed bioaerosol samplers with those commercially available showed that the incorporation of our research findings into the design of the new samplers yields better performance data than data from currently available samplers. PMID:16349217

  8. Measurements of the elemental and isotopic composition of interplanetary dust collected on LDEF. [Long Duration Exposure Facility

    NASA Technical Reports Server (NTRS)

    Fechtig, H.; Jessberger, E.; Hoerz, F.; Igenbergs, E.; Kuczera, H.

    1985-01-01

    A passive interplanetary dust collection experiment, currently in orbit aboard the Long Duration Exposure Facility, is described. The collectors, germanium target plates covered by metallized Mylar foils, are designed for secondary ion mass spectrometry measurements of the elemental and isotopic compositions of residues resulting from micrometeoroid (greater than 10 to the -10th grams) impacts. Impact simulation experiments have demonstrated the validity of the collection concept. Quantitative elemental analyses are complicated by the nonuniform distribution of projectile-derived elements.

  9. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites.

    PubMed

    Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

    2015-01-01

    Blasting is an integral part of large-scale open cut mining that often occurs in close proximity to population centers and often results in the emission of particulate material and gases potentially hazardous to health. Current air quality monitoring methods rely on limited numbers of fixed sampling locations to validate a complex fluid environment and collect sufficient data to confirm model effectiveness. This paper describes the development of a methodology to address the need of a more precise approach that is capable of characterizing blasting plumes in near-real time. The integration of the system required the modification and integration of an opto-electrical dust sensor, SHARP GP2Y10, into a small fixed-wing and multi-rotor copter, resulting in the collection of data streamed during flight. The paper also describes the calibration of the optical sensor with an industry grade dust-monitoring device, Dusttrak 8520, demonstrating a high correlation between them, with correlation coefficients (R(2)) greater than 0.9. The laboratory and field tests demonstrate the feasibility of coupling the sensor with the UAVs. However, further work must be done in the areas of sensor selection and calibration as well as flight planning. PMID:26274959

  10. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites

    PubMed Central

    Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

    2015-01-01

    Blasting is an integral part of large-scale open cut mining that often occurs in close proximity to population centers and often results in the emission of particulate material and gases potentially hazardous to health. Current air quality monitoring methods rely on limited numbers of fixed sampling locations to validate a complex fluid environment and collect sufficient data to confirm model effectiveness. This paper describes the development of a methodology to address the need of a more precise approach that is capable of characterizing blasting plumes in near-real time. The integration of the system required the modification and integration of an opto-electrical dust sensor, SHARP GP2Y10, into a small fixed-wing and multi-rotor copter, resulting in the collection of data streamed during flight. The paper also describes the calibration of the optical sensor with an industry grade dust-monitoring device, Dusttrak 8520, demonstrating a high correlation between them, with correlation coefficients (R2) greater than 0.9. The laboratory and field tests demonstrate the feasibility of coupling the sensor with the UAVs. However, further work must be done in the areas of sensor selection and calibration as well as flight planning. PMID:26274959

  11. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites.

    PubMed

    Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

    2015-01-01

    Blasting is an integral part of large-scale open cut mining that often occurs in close proximity to population centers and often results in the emission of particulate material and gases potentially hazardous to health. Current air quality monitoring methods rely on limited numbers of fixed sampling locations to validate a complex fluid environment and collect sufficient data to confirm model effectiveness. This paper describes the development of a methodology to address the need of a more precise approach that is capable of characterizing blasting plumes in near-real time. The integration of the system required the modification and integration of an opto-electrical dust sensor, SHARP GP2Y10, into a small fixed-wing and multi-rotor copter, resulting in the collection of data streamed during flight. The paper also describes the calibration of the optical sensor with an industry grade dust-monitoring device, Dusttrak 8520, demonstrating a high correlation between them, with correlation coefficients (R(2)) greater than 0.9. The laboratory and field tests demonstrate the feasibility of coupling the sensor with the UAVs. However, further work must be done in the areas of sensor selection and calibration as well as flight planning.

  12. Natural and anthropogenic radionuclides in airborne particulate samples collected in Barcelona (Spain).

    PubMed

    Vallés, I; Camacho, A; Ortega, X; Serrano, I; Blázquez, S; Pérez, S

    2009-02-01

    Results for naturally occurring (7)Be, (210)Pb, (40)K, (214)Bi, (214)Pb, (212)Pb, (228)Ac and (208)Tl and anthropogenic (137)Cs in airborne particulate matter in the Barcelona area during the period from January 2001 to December 2005 are presented and discussed. The (212)Pb and (208)Tl, (214)Bi and (214)Pb, (7)Be and (210)Pb radionuclide levels showed a significant correlation with each other, with correlation coefficients of 0.99, 0.78 and 0.69, respectively, suggesting similar origin/behaviour of these radionuclides in the air. Caessium-137 and Potassium-40 were transported to the air as resuspended particle from the soil. The (7)Be and (210)Pb concentrations showed similar seasonal variations, with a tendency for maximum concentrations during the summer months. An inverse relationship was observed between the (7)Be, (210)Pb, (40)K and (137)Cs concentrations and weekly rainfall, indicating washout of atmospheric aerosols carrying these radionuclides. PMID:19027201

  13. 78 FR 28242 - Proposed Information Collection; Cleanup Program for Accumulations of Coal and Float Coal Dusts...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ... were published (35 FR 17097, November 20, 1970) as part of a final rule that implemented requirements... Coal and Float Coal Dusts, Loose Coal, and Other Combustibles AGENCY: Mine Safety and Health... program for accumulations of coal and float coal dusts, loose coal, and other combustibles in...

  14. 77 FR 38323 - Proposed Extension of Existing Information Collection; Respirable Coal Mine Dust Sampling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... to respirable coal mine dust containing quartz has been associated with some miners developing silicosis (black lung), the 2.0 mg/m\\3\\ standard is further reduced, using the formula 10 / % quartz, when the respirable dust contains more than 5 percent quartz. Parts 70 and 71 also require each coal...

  15. Efficiency of dust sampling inlets in calm air.

    PubMed

    Breslin, J A; Stein, R L

    1975-08-01

    Measurement of airborne dust concentrations usually involves drawing a sample of the dust-laden air into the measuring instrument through an inlet. Even if the surrounding air is calm, theoretical calculations predict that large particles may not be sampled accurately due to the combined effects of gravity and inertia on the particles near the sampling inlet. Tests were conducted to determine the conditions of particle size, inlet radius, and flow rare necessary for accurate dust sampling. A coal-dust aerosol was sampled simultaneously through inlets of different diameters at the same volume flow-rate and collected on filters. The dust was removed from the filters and the particles were counted and sized with a Coulter counter. Results showed that published criteria for inlet conditions for correct sampling are overly restrictive and that respirable-size particles are sampled correctly in the normal range or operation of most dust sampling instruments. PMID:1227283

  16. Impurities of Resorcinol Bis(diphenyl phosphate) in Plastics and Dust Collected on Electric/Electronic Material.

    PubMed

    Ballesteros-Gómez, Ana; Aragón, Álvaro; Van den Eede, Nele; de Boer, Jacob; Covaci, Adrian

    2016-02-16

    Resorcinol bis(diphenylphosphate) (RDP) is an organophosphorus flame retardant widely used in electric and electronic equipment. It has been detected in house dust of several European countries according to recent literature. Similar to other flame retardants, RDP formulations and products treated with RDP, such as plastics, can contain RDP impurities, byproducts and breakdown products. In this study, we use screening methods based on wide scope solvent extraction and high resolution time-of-flight mass spectrometry for the identification of RDP related compounds in products and in dust. We analyzed both plastics from electrical/electronic equipment that contained RDP and indoor dust collected on and around surfaces of this equipment. A variety of compounds, namely TPHP, hydroxylated TPHP and RDP (meta-HO-TPHP and meta-HO-RDP), dihydroxylated TPHP, RDP with the loss of a phenyl group (RDP-[Phe]) and RDP oligomers were detected in plastics containing high levels of RDP. Regarding dust samples collected on electronics, TPHP meta-HO-TPHP, meta-HO-RDP, RDP-[Phe] and RDP oligomers were detected. High concentrations of meta-HO-TPHP (20-14 227 ng/g), TPHP (222-50 728 ng/g) and RDP (23-29 118 ng/g) were found in many of the dust samples, so that these compounds seem to easily migrate into the environment. These RDP impurities, byproducts and breakdown products are for the first time reported in indoor dust. Meta-HO-TPHP could be relevant for future biomonitoring studies concerning flame retardants.

  17. Analysis of dust samples collected from spent nuclear fuel interim storage containers at Hope Creek, Delaware, and Diablo Canyon, California.

    SciTech Connect

    Bryan, Charles R.; Enos, David George

    2014-07-01

    Potentially corrosive environments may form on the surface of spent nuclear fuel dry storage canisters by deliquescence of deposited dusts. To assess this, samples of dust were collected from in-service dry storage canisters at two near-marine sites, the Hope Creek and Diablo Canyon storage installations, and have been characterized with respect to mineralogy, chemistry, and texture. At both sites, terrestrially-derived silicate minerals, including quartz, feldspars, micas, and clays, comprise the largest fraction of the dust. Also significant at both sites were particles of iron and iron-chromium metal and oxides generated by the manufacturing process. Soluble salt phases were minor component of the Hope Creek dusts, and were compositionally similar to inland salt aerosols, rich in calcium, sulfate, and nitrate. At Diablo Canyon, however, sea-salt aerosols, occurring as aggregates of NaCl and Mg-sulfate, were a major component of the dust samples. The seasalt aerosols commonly occurred as hollow spheres, which may have formed by evaporation of suspended aerosol seawater droplets, possibly while rising through the heated annulus between the canister and the overpack. The differences in salt composition and abundance for the two sites are attributed to differences in proximity to the open ocean and wave action. The Diablo Canyon facility is on the shores of the Pacific Ocean, while the Hope Creek facility is on the shores of the Delaware River, several miles from the open ocean.

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

    NASA Astrophysics Data System (ADS)

    Holmes, S. A.

    2009-12-01

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

  19. Lofting of dust by very large explosions

    SciTech Connect

    Mason, A.S.; Finnegan, D.L.; Hagan, R.C.; Raymond, R. Jr.; Cocks, G.G.; Zoller, W.H.; Peach, C.L.

    1987-08-01

    One of the goals of the Minor Scale test was to determine the quantity, form, and composition of dust lofted by a large detonation of a conventional high explosive at ground level. The explosive charge was 4427 tonnes of ammonium nitrate-fuel oil (ANFO), whose blast effect is approximately equal to that of an 8 kT nuclear device. The experimental techniques used to determine the amount of dust were (1) use of elements in soil as natural tracers, (2) inclusion of tracer elements in the ANFO charge and the immediate surroundings, (3) airborne collection of the lofted dust on filter media, and (4) analysis of the samples for both tracers and dust. The tracer content of the sample can then relate the dust collected to the total amount lofted and to the location of its origin within the experimental setup. Indium, in the oxide form, was placed within the explosive charge, and tantalum as very fine dust, was placed near the soil surface immediately adjacent to the charge container. The amounts of the tracers and of dust collected by each filter were measured by instrumental neutron activation analysis. A research aircraft equipped with well-characterized high-volume filter samplers was flown through the dust cloud at 10 levels between the top at 4.6 km and the bottom at 1.7 km above ground level. The cloud dust density was distinctly biomodal; its maxima were at 4.1 and 2.9 km. The majority of the indium was associated with the dust in the upper part of the cloud, and the majority of the tantalum was in the lower part. The estimate of the total dust lofted by use of the naturally occurring tracers was 3.0 x 10/sup 9/ g. Samples are being studied by scanning electron microscopy to determine their particle size and composition distributions as functions of location within the cloud.

  20. COMPARISON OF METHODS FOR DETECTION AND ENUMERATION OF AIRBORNE MICROORGANISMS COLLECTED BY LIQUID IMPINGEMENT

    EPA Science Inventory

    Bacterial agents and cell components can be spread as bioaerosols, producing infections and asthmatic problems. This study compares four methods for the detection and enumeration of aerosolized bacteria collected in an AGI-30 impinger. Changes in the total and viable concentratio...

  1. Comparison of methods for detection and enumeration of airborne microorganisms collected by liquid impingement.

    PubMed Central

    Terzieva, S; Donnelly, J; Ulevicius, V; Grinshpun, S A; Willeke, K; Stelma, G N; Brenner, K P

    1996-01-01

    Bacterial agents and cell components can be spread as bioaerosols, producing infections and asthmatic problems. This study compares four methods for the detection and enumeration of aerosolized bacteria collected in an AGI-30 impinger. Changes in the total and viable concentrations of Pseudomonas fluorescens in the collection fluid with respect to time of impingement were determined. Two direct microscopic methods (acridine orange and BacLight) and aerodynamic aerosol-size spectrometry (Aerosizer) were employed to measure the total bacterial cell concentrations in the impinger collection fluid and the air, respectively. These data were compared with plate counts on selective (MacConkey agar) and nonselective (Trypticase soy agar) media, and the percentages of culturable cells in the collection fluid and the bacterial injury response to the impingement process were determined'. The bacterial collection rate was found to be relatively unchanged during 60 min of impingement. The aerosol measurements indicated an increased amount of cell fragments upstream of the impinger due to continuous bacterial nebulization. Some of the bacterial clusters, present in the air upstream of the impinger, deagglomerated during impingement, thus increasing the total bacterial count by both direct microscopic methods. The BacLight staining technique was also used to determine the changes in viable bacterial concentration during the impingement process. The percentage of viable bacteria, determined as a ratio of BacLight live to total counts was only 20% after 60 min of sampling. High counts on Trypticase soy agar indicated that most of the injured cells could recover. On the other hand, the counts from the MacConkey agar were very low, indicating that most of the cells were structurally damaged in the impinger. The comparison of data on the percentage of injured bacteria obtained by the traditional plate count with the data on percentage of nonviable bacteria obtained by the Bac

  2. Physics of spacecraft-based interplanetary dust collection by impact into low-density media

    NASA Technical Reports Server (NTRS)

    Anderson, William W.; Ahrens, T. J.

    1994-01-01

    A spacecraft encountering an interplanetary dust particle (IDP) at a relative velocity of several kilometers per second may be used to capture that particle for in situ analysis or for analysis upon Earth return. In this paper we study the impact of a dust particle into a low-density medium (i.e., a foam) such that the foam dissipates the kinetic energy of impact over a sufficient distance to stop the particle without destroying it.

  3. Chemical speciation of lead dust associated with primary lead smelting.

    PubMed Central

    Spear, T M; Svee, W; Vincent, J H; Stanisich, N

    1998-01-01

    The research presented in this article assessed geochemical factors relating to dust produced during primary lead smelting. Bulk dust samples and size-selective airborne dust samples were collected from four areas of a primary lead smelter and analyzed by X-ray diffraction and sequential chemical extraction. X-ray diffraction showed that the smelter dusts were composed primarily of sulfides, oxides, sulfates, and silicates of metal ores, with galena being the primary dust component. Sequential extraction revealed the solubility of lead compounds at less than 7% in the exchangeable and mildly acidic steps for the bulk dusts collected from four smelter areas. The later steps of the extraction procedure were more effective in dissolving the lead compounds associated with the bulk dust samples, with 43%, 26%, and 8% of the total lead, in the ore storage, sinter, and blast/dross smelter areas, respectively, being extracted in the residual step. Sequential extraction of coarse airborne dust samples from the ore storage and sinter plant showed that 1.2% and 4.1% of the total lead, respectively, was exchangeable. The finer particle size fractions from these areas of the smelter showed higher percentages of exchangeable lead. Of the course airborne dust from the blast/dross furnace processes, 65% of the total lead was exchangeable. However, the largest percentage of lead from these areas was associated with the finer particle-size fractions. If lead bioavailability is related to its solubility as determined through sequential extraction, the health hazards associated with lead exposure may be appreciably enhanced in the blast and dross furnace processes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9721256

  4. Interplanetary dust particles collected in the stratosphere: observations of atmospheric heating and constraints on their interrelationships and sources.

    PubMed

    Sandford, S A; Bradley, J P

    1989-01-01

    The majority of the interplanetary dust particles (IDPs) collected in the stratosphere belong to one of three major classes, the first two dominated by the anhydrous minerals olivine and pyroxene, and the third by hydrous layer-lattice silicates. Infrared spectroscopy and transmission electron microscopy studies show that the different IDP classes represent different types of dust that exist as individual particles in interplanetary space. The majority of the collected IDPs smaller than 30 micrometers in diameter in the layer-lattice silicate and pyroxene classes appear not to have been heated to temperatures above 600 degrees C during atmospheric entry. The relatively low maximum temperatures experienced by these IDPs during atmospheric entry imply that they arrive at the top of the atmosphere with low geocentric encounter velocities. This limits the possible encounter trajectories for these particles to relatively circular, prograde orbits. As a result, it is unlikely that these IDPs are from Earth-crossing comets or asteroids. Asteroids, and comets having low inclinations and perihelia outside 1.2 AU, appear to be the best candidates for the parent bodies of the pyroxene and layer-lattice silicate particles. Chemical and mineralogical information suggests that the pyroxene-rich IDPs are from comets and the layer-lattice silicate-rich IDPs are from asteroids. The collected IDPs dominated by olivine appear to include a larger fraction of particles heating above 600 degrees C, suggesting that these particles were captured from more eccentric orbits. This, and the observation of the infrared spectral features of olivine in several comets suggest these particles have a cometary origin. Since much of the collected dust has apparently been captured from nearly circular, prograde orbits and since there are no appropriate parent bodies presently in such orbits, these results provide an experimental confirmation that the Poynting-Robertson effect exists as a

  5. Culturability of Bacillus spores on aerosol collection filters exposed to airborne combustion products of Al, Mg, and B·Ti.

    PubMed

    Adhikari, Atin; Yermakov, Michael; Indugula, Reshmi; Reponen, Tiina; Driks, Adam; Grinshpun, Sergey A

    2016-05-01

    Destruction of bioweapon facilities due to explosion or fire could aerosolize highly pathogenic microorganisms. The post-event air quality assessment is conducted through air sampling. A bioaerosol sample (often collected on a filter for further culture-based analysis) also contains combustion products, which may influence the microbial culturability and, thus, impact the outcome. We have examined the interaction between spores deposited on collection filters using two simulants of Bacillus anthracis [B. thuringiensis (Bt) and B. atrophaeus (referred to as BG)] and incoming combustion products of Al as well as Mg and B·Ti (common ingredient of metalized explosives). Spores extracted from Teflon, polycarbonate, mixed cellulose ester (MCE), and gelatin filters (most common filter media for bioaerosol sampling), which were exposed to combustion products during a short-term sampling, were analyzed by cultivation. Surprisingly, we observed that aluminum combustion products enhanced the culturability of Bt (but not BG) spores on Teflon filters increasing the culturable count by more than an order of magnitude. Testing polycarbonate and MCE filter materials also revealed a moderate increase of culturability although gelatin did not. No effect was observed with either of the two species interacting on either filter media with products originated by combustion of Mg and B·Ti. Sample contamination, spore agglomeration, effect of a filter material on the spore survival, changes in the spore wall ultrastructure and germination, as well as other factors were explored to interpret the findings. The study raises a question about the reliability of certain filter materials for collecting airborne bio-threat agents in combustion environments. PMID:26914458

  6. Culturability of Bacillus spores on aerosol collection filters exposed to airborne combustion products of Al, Mg, and B·Ti.

    PubMed

    Adhikari, Atin; Yermakov, Michael; Indugula, Reshmi; Reponen, Tiina; Driks, Adam; Grinshpun, Sergey A

    2016-05-01

    Destruction of bioweapon facilities due to explosion or fire could aerosolize highly pathogenic microorganisms. The post-event air quality assessment is conducted through air sampling. A bioaerosol sample (often collected on a filter for further culture-based analysis) also contains combustion products, which may influence the microbial culturability and, thus, impact the outcome. We have examined the interaction between spores deposited on collection filters using two simulants of Bacillus anthracis [B. thuringiensis (Bt) and B. atrophaeus (referred to as BG)] and incoming combustion products of Al as well as Mg and B·Ti (common ingredient of metalized explosives). Spores extracted from Teflon, polycarbonate, mixed cellulose ester (MCE), and gelatin filters (most common filter media for bioaerosol sampling), which were exposed to combustion products during a short-term sampling, were analyzed by cultivation. Surprisingly, we observed that aluminum combustion products enhanced the culturability of Bt (but not BG) spores on Teflon filters increasing the culturable count by more than an order of magnitude. Testing polycarbonate and MCE filter materials also revealed a moderate increase of culturability although gelatin did not. No effect was observed with either of the two species interacting on either filter media with products originated by combustion of Mg and B·Ti. Sample contamination, spore agglomeration, effect of a filter material on the spore survival, changes in the spore wall ultrastructure and germination, as well as other factors were explored to interpret the findings. The study raises a question about the reliability of certain filter materials for collecting airborne bio-threat agents in combustion environments.

  7. Transport of Alaskan Dust into the Gulf of Alaska and Comparison with Similar High-Latitude Dust Environments

    NASA Technical Reports Server (NTRS)

    Crusium, John; Levy, Rob; Wang, Jun; Campbell, Rob; Schroth, Andrew W.

    2012-01-01

    Transport of Alaskan dust into the Gulf of Alaska and comparison with similar high-latitude dust environments. An airborne flux of the micronutrient iron, derived from dust originating from coastal regions may be an important contributor of iron to the Gulf of Alaska's (GoA) oligotrophic waters. Dust blowing off glacier termini and dry riverbeds is a recurring phenomenon in Alaska, usually occurring in the autumn. Since previous studies assumed that dust originating in the deserts of Asia was the largest source of . airborne iron to the GoA, the budget of aeolian deposition of iron needs to be reassessed. Since late 20 I 0, our group has been monitoring dust activity using satellites over the Copper River Delta (CRD) where the most vigorous dust plumes have been observed. Since 2011, sample aerosol concentration and their composition are being collected at Middleton Island (100km off shore of CRD). This presentation will show a summary of the ongoing dust observations and compare with other similar environments (Patagonia, Iceland) by showing case studies. Common features will be highlighted

  8. Gene expression profiling and pathway analysis of human bronchial epithelial cells exposed to airborne particulate matter collected from Saudi Arabia

    PubMed Central

    Sun, Hong; Shamy, Magdy; Kluz, Thomas; Muñoz, Alexandra B.; Zhong, Mianhua; Laulicht, Freda; Alghamdi, Mansour A.; Khoder, Mamdouh I.; Chen, Lung-Chi; Costa, Max

    2013-01-01

    Epidemiological studies have established a positive correlation between human mortality and increased concentration of airborne particulate matters (PM). However, the mechanisms underlying PM related human diseases, as well as the molecules and pathways mediating the cellular response to PM, are not fully understood. This study aims to investigate the global gene expression changes in human cells exposed to PM10 and to identify genes and pathways that may contribute to PM related adverse health effects. Human bronchial epithelial cells were exposed to PM10 collected from Saudi Arabia for 1 or 4 days, and whole transcript expression was profiled using the GeneChip human gene 1.0 ST array. A total of 140 and 230 genes were identified that significantly changed more than 1.5 fold after PM10 exposure for 1 or 4 days, respectively. Ingenuity Pathway Analysis revealed that different exposure durations triggered distinct pathways. Genes involved in NRF2-mediated response to oxidative stress were up-regulated after 1 day exposure. In contrast, cells exposed for 4 days exhibited significant changes in genes related to cholesterol and lipid synthesis pathways. These observed changes in cellular oxidative stress and lipid synthesis might contribute to PM related respiratory and cardiovascular disease. PMID:23085030

  9. Extracts of airborne particulates collected at different locations in the Copenhagen area induce the expression of cytochrome P-450IA1

    SciTech Connect

    Roepstorff, V.; Ostenfeldt, N.; Autrup, H. )

    1990-08-01

    Acetone extracts of airborne particulates collected at different sites in the greater Copenhagen area were tested for their ability to induce the expression of cytochrome P-450IA1 RNA in a human breast cancer cell line, T47-D. The induction efficiency was expressed as an benz(a) anthracene equivalents, that is, the amount of benz(a)anthracene required to give the same level of induction. A significantly higher level of induction of P-450IA1 RNA was seen with samples collected on days with a smog alert. The inducibility of samples collected in rural areas was lower, but no significant difference in inducibility was found between samples collected in urban and suburban areas. Lack of correlation between the mutagenic activity in the Ames assay and the P-450IA1-inducing activity of the samples suggests that the complex mixture of compounds found in airborne particulates may have different biological activities in the two short-term test systems. Measurements of P-450IA1 inducibility provide a new, sensitive approach to assess the biological activity of material present in air pollution. The presence in airborne particulates of chemical compounds that induce cytochrome P-450IA1 an enzyme responsible for the metabolism of ubiquitous chemical carcinogens, suggests that the general environment may change an individual's response to the impact of exogenous chemicals, including the carcinogens present in cigarette smoke.

  10. Effect of prior dust collection on detection, counting efficiency, and energy resolution for alpha continuous air monitors

    SciTech Connect

    Newton, G.J.; Hoover, M.D.

    1994-11-01

    For the past several years, we have supported the DOE Waste Isolation Pilot Plant (WIPP) project by evaluating the capabilities and performance of the Eberline Alpha 6 continuous air monitor (CAM). This evalution has focused on the ability of the CAM to correctly report plutonium in the presence of salt dust. Tests involving the simultaneous collection of plutonium and salt have shown that burial by salt can degrade the detection of plutonium, but that this interference is negligible when salt concentrations are below about 0.2 mg/m{sup 3}. Throughout the evalution, it has been assumed that salt burial is a concern for slow, chronic release of plutonium, but that any acute release of plutonium would be collected on the top surface of the filter or salt and would be unattenuated. The spectral quality of alpha radiation detection on membrane filters is observed to improve with filter loading. This is attributed to the probability that accumulations of dust tend to fill in surface irregularities of the collection filter at a a faster rate than they create additional surface irregularities. The validity of these assumptions about the improved detection of plutonium on salt-layer surfaces has recently been questioned. Based on electron micrographic examination of salt-laden filters, it has been speculated that collection of salt dust on a membrane filter results in formation of pores, fissures, and dendritic shapes of salt on the filter surface. If plutonium were collected, particles could penetrate into the pores and fissures, resulting in a degraded or lost signal from the plutonium. Because no experimental evidence existed to answer the concern, the purpose of the current study was to quantify any differences between detection of plutonium on clean or salt-laden filters.

  11. Characterization of Airborne Particles Collected from Car Engine Air Filters Using SEM and EDX Techniques

    PubMed Central

    Heredia Rivera, Birmania; Gerardo Rodriguez, Martín

    2016-01-01

    Particulate matter accumulated on car engine air-filters (CAFs) was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of particles were studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed particles by friction, and the second consisted of particles retained on the filters. Larger particles with a diameter of 74–10 µm were observed in the first category. In the second one, the detected particles had a diameter between 16 and 0.7 µm. These particles exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt), metallic (mainly Fe), and biological particles (vegetal and animal debris). The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric particles, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of filters and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city. PMID:27706087

  12. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, C.-W.; James, J. T.; Taylor, L.; Zeidler-Erdely, P. C.; Castranova, V.

    2009-01-01

    NASA will build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of fine, reactive dust. Astronauts on the Moon will go in and out of the base for various activities, and will inevitably bring some dust into the living quarters. Depressurizing the airlock so that astronauts can exit for outdoor activities could also bring dust inside the airlock to the habitable area. Concerned about the potential health effects on astronauts exposed to airborne lunar dust, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust. The toxicity data also will be needed by toxicologists to establish safe exposure limits for astronauts residing in the lunar habitat and by environmental engineers to design an appropriate dust mitigation strategy. We conducted a study to examine biomarkers of toxicity (inflammation and cytotoxicity) in lung lavage fluids from mice intrapharyngeally instilled with lunar dust samples; we also collected lung tissue from the mice for histopathological examination 3 months after the dust instillation. Reference dusts (TiO2 and quartz) having known toxicities and industrial exposure limits were studied in parallel with lunar dust so that the relative toxicity of lunar dust can be determined. A 6-month histopathology study has been planned. These instillation experiments will be followed by inhalation studies, which are more labor intensive and technologically difficult. The animal inhalation studies will be conducted first with an appropriate lunar dust simulant to ensure that the exposure techniques to be used with actual lunar dust will be successful. The results of these studies collectively will reveal the toxicological risk of exposures and enable us to establish exposure limits on lunar dust for astronauts living in the lunar habitat.

  13. Airborne biological particles and electric fields

    NASA Astrophysics Data System (ADS)

    Benninghoff, William S.; Benninghoff, Anne S.

    1982-01-01

    In November and December 1977 at McMurdo Station in Antarctica we investigated the kinds, numbers, and deposition of airborne particles larger than 2 μm while measuring electric field gradient at 2.5 m above the ground. Elementary collecting devices were used: Staplex Hi-Volume and Roto-rod samplers, Tauber (static sedimentation) traps, petrolatum-coated microscope slides, and snow (melted and filtered). The electric fields were measured by a rotating dipole (Stanford Radioscience Laboratory field mill number 2). During periods of blowing snow and dust the electric field gradient was + 500 to + 2500 V/m, and Tauber traps with grounded covers collected 2 or more times as much snow and dust as the ones with ungrounded covers. During falling snow the electric field gradient was -1000 to -1500 V/m, and the ungrounded traps collected almost twice as much snow and dust as those grounded. These observations suggest that under the prevailing weather conditions in polar regions the probable net effect is deposition of greater quantities of dust, including diaspores and minute organisms, on wet, grounded surfaces. This hypothesis needs examination for its use in explanation of biological distribution patterns.

  14. Gene expression profiling and pathway analysis of human bronchial epithelial cells exposed to airborne particulate matter collected from Saudi Arabia

    SciTech Connect

    Sun, Hong; Shamy, Magdy; Kluz, Thomas; Muñoz, Alexandra B.; Zhong, Mianhua; Laulicht, Freda; Alghamdi, Mansour A.; Khoder, Mamdouh I.; Chen, Lung-Chi; Costa, Max

    2012-12-01

    Epidemiological studies have established a positive correlation between human mortality and increased concentration of airborne particulate matters (PM). However, the mechanisms underlying PM related human diseases, as well as the molecules and pathways mediating the cellular response to PM, are not fully understood. This study aims to investigate the global gene expression changes in human cells exposed to PM{sub 10} and to identify genes and pathways that may contribute to PM related adverse health effects. Human bronchial epithelial cells were exposed to PM{sub 10} collected from Saudi Arabia for 1 or 4 days, and whole transcript expression was profiled using the GeneChip human gene 1.0 ST array. A total of 140 and 230 genes were identified that significantly changed more than 1.5 fold after PM{sub 10} exposure for 1 or 4 days, respectively. Ingenuity Pathway Analysis revealed that different exposure durations triggered distinct pathways. Genes involved in NRF2-mediated response to oxidative stress were up-regulated after 1 day exposure. In contrast, cells exposed for 4 days exhibited significant changes in genes related to cholesterol and lipid synthesis pathways. These observed changes in cellular oxidative stress and lipid synthesis might contribute to PM related respiratory and cardiovascular disease. -- Highlights: ► PM exposure modulated gene expression and associated pathways in BEAS-2B cells. ► One-day exposure to PM induced genes involved in responding to oxidative stress. ► 4-day exposure to PM changed genes associated to cholesterol and lipid synthesis.

  15. Analysis of Dust Samples Collected from an Unused Spent Nuclear Fuel Interim Storage Container at Hope Creek, Delaware.

    SciTech Connect

    Bryan, Charles R.; Enos, David

    2015-03-01

    In July, 2014, the Electric Power Research Institute and industry partners sampled dust on the surface of an unused canister that had been stored in an overpack at the Hope Creek Nuclear Generating Station for approximately one year. The foreign material exclusion (FME) cover that had been on the top of the canister during storage, and a second recently - removed FME cover, were also sampled. This report summarizes the results of analyses of dust samples collected from the unused Hope Creek canister and the FME covers. Both wet and dry samples of the dust/salts were collected, using SaltSmart(TM) sensors and Scotch - Brite(TM) abrasive pads, respectively. The SaltSmart(TM) samples were leached and the leachate analyzed chemically to determine the composition and surface load per unit area of soluble salts present on the canister surface. The dry pad samples were analyzed by X-ray fluorescence and by scanning electron microscopy to determine dust texture and mineralogy; and by leaching and chemical analysis to deter mine soluble salt compositions. The analyses showed that the dominant particles on the canister surface were stainless steel particles, generated during manufacturing of the canister. Sparse environmentally - derived silicates and aluminosilicates were also present. Salt phases were sparse, and consisted of mostly of sulfates with rare nitrates and chlorides. On the FME covers, the dusts were mostly silicates/aluminosilicates; the soluble salts were consistent with those on the canister surface, and were dominantly sulfates. It should be noted that the FME covers were w ashed by rain prior to sampling, which had an unknown effect of the measured salt loads and compositions. Sulfate salts dominated the assemblages on the canister and FME surfaces, and in cluded Ca - SO4 , but also Na - SO4 , K - SO4 , and Na - Al - SO4 . It is likely that these salts were formed by particle - gas conversion reactions, either

  16. Observations on the use of membrane filtration and liquid impingement to collect airborne microorganisms in various atmospheric environments

    USGS Publications Warehouse

    Griffin, Dale W.; Gonzalez, C.; Teigell, N.; Petrosky, T.; Northup, D.E.; Lyles, M.

    2011-01-01

    The influence of sample-collection-time on the recovery of culturable airborne microorganisms using a low-flow-rate membrane-filtration unit and a high-flow-rate liquid impinger were investigated. Differences in recoveries were investigated in four different atmospheric environments, one mid-oceanic at an altitude of ~10.0 m, one on a mountain top at an altitude of ~3,000.0 m, one at ~1.0 m altitude in Tallahassee, Florida, and one at ~1.0 m above ground in a subterranean-cave. Regarding use of membrane filtration, a common trend was observed: the shorter the collection period, the higher the recovery of culturable bacteria and fungi. These data also demonstrated that lower culturable counts were common in the more remote mid-oceanic and mountain-top atmospheric environments with bacteria, fungi, and total numbers averaging (by sample time or method categories) <3.0 colony-forming units (CFU) m -3. At the Florida and subterranean sites, the lowest average count noted was 3.5 bacteria CFU m-3, and the highest averaged 140.4 total CFU m-3. When atmospheric temperature allowed use, the high-volume liquid impinger utilized in this study resulted in much higher recoveries, as much as 10?? greater in a number of the categories (bacterial, fungal, and total CFU). Together, these data illustrated that (1) the high-volume liquid impinger is clearly superior to membrane filtration for aeromicrobiology studies if start-up costs are not an issue and temperature permits use; (2) although membrane filtration is more cost friendly and has a 'typically' wider operational range, its limits include loss of cell viability with increased sample time and issues with effectively extracting nucleic acids for community-based analyses; (3) the ability to recover culturable microorganisms is limited in 'extreme' atmospheric environments and thus the use of a 'limited' methodology in these environments must be taken into account; and (4) the atmosphere culls, i.e., everything is not

  17. Haul road dust control

    SciTech Connect

    Reed, W.R.; Organiscak, J.A.

    2007-10-15

    A field study was conducted to measure dust from haul trucks at a limestone quarry and a coal preparation plant waste hauling operation. The study found that primarily wind, distance and road treatment conditions notably affected the dust concentrations at locations next to, 50 ft from, and 100 ft away from the unpaved haulage road. Airborne dust measured along the unpaved haul road showed that high concentrations of fugitive dust can be generated with these concentrations rapidly decreasing to nearly background levels within 100 ft of the road. Instantaneous respirable dust measurements illustrated that the trucks generate a real-time dust cloud that has a peak concentration with a time-related decay rate as the dust moves past the sampling locations. The respirable dust concentrations and peak levels were notably diminished as the dust cloud was transported, diluted, and diffused by the wind over the 100 ft distance from the road. Individual truck concentrations and peak levels measured next to the dry road surface test section were quite variable and dependent on wind conditions, particularly wind direction, with respect to reaching the sampling location. The vast majority of the fugitive airborne dust generated from unpaved and untreated haulage roads was non-respirable. 6 figs.

  18. Intergalactic Dust

    NASA Astrophysics Data System (ADS)

    Li, A.

    2002-12-01

    We study the composition and sizes of intergalactic dust based on the expulsion of interstellar dust from the galactic disk. Interstellar grains in the Galactic disk are modelled as a mixture of amorphous silicate dust and carbonaceous dust consisting of polycyclic aromatic hydrocarbon (PAH) molecules and larger graphitic grains (Li & Draine 2001) with size distributions like those of the Milky Way dust (Weingartner & Draine 2001). We model their dynamic evolution in terms of the collective effects caused by (1) radiative acceleration, (2) gravitational attraction, (3) gas drag, (4) thermal sputtering, and (5) Lorenz force from the galactic magnetic field (Ferrara et al. 1991). Radiation pressure from the stellar disk exerts an upward force on dust grains and may ultimately expel them out of the entire galaxy. Gravitational force from the stellar, dust and gas disk as well as the dark matter halo exerts a downward force. Thermal sputtering erodes all grains to some degree but more efficiently destroys small grains. This, together with the fact that (1) very small grains (with small radiation pressure efficiencies) are not well coupled to starlight; (2) for large grains the radiative force to the gravitational force is approximately inversely proportional to grain size, acts as a size ``filter'' for dust leaking into the intergalactic space. Since the radiation pressure efficiency and the grain destruction rate are sensitive to dust composition, the relative importance of carbon dust compared to silicate dust expelled into the intergalactic space differs from that in the galactic plane. We derive the size distributions of both silicate and carbonaceous dust finally getting into the intergalactic space and obtain an intergalactic extinction curve. The predicted intergalactic infrared emission spectrum is calculated. References: Ferrara, A., Ferrini, F., Franco, J., & Barsella, B. 1991, ApJ, 381, 137 Li, A., & Draine, B.T. 2001, ApJ, 554, 778 Weingartner, J

  19. The Nature of Interstellar Dust

    NASA Technical Reports Server (NTRS)

    Huss, G. R.

    2003-01-01

    The STARDUST mission is designed to collect dust the coma of comet Wild 2 and to collect interstellar dust on a second set of collectors. We have a reasonable idea of what to expect from the comet dust collection because the research community has been studying interplanetary dust particles for many years. It is less clear what we should expect from the interstellar dust. This presentation discusses what we might expect to find on the STARDUST interstellar dust collector.

  20. Pneumoconiosis, lung function and exposure to airborne dust: epidemiological research to compare responses of working coalminers with responses of ex-miners. Part 2. Final report

    SciTech Connect

    Soutar, C.A.; Maclaren, W.; Hurley, F.; Murdoch, R.; Hadden, G.

    1982-03-01

    The relationship between dust exposure and disease for miners was compared with that for ex-miners, in order to determine whether relationships found in other studies on miners alone could be applied to both groups. 17,738 men examined in the 1950s were followed up approximately 22 years later. Sixty one per cent of the survivors were examined, being 40% of the original sample. Records were made of respiratory symptoms, smoking habit, lung spirometry and chest radiograph findings. Radiographs were interpreted according to the International Labour Office Classification of Pneumoconiosis. Lifetime dust exposure was calculated for each subject. The dust/disease relationship was found to be the same for both groups. Ex-miners were found to have more pneumoconiosis and fibrosis and to be in worse health than miners. Pneumoconiosis progression was shown to be related to continued dust exposure; fibrosis progression was related to the presence of dust in the lungs. Dust exposure was shown to cause a mainly restrictive pattern of lung disease in contrast to the obstructive pattern caused by smoking. Colliery-related differences were found in lung disease which it was felt needed further investigation.

  1. Characterization of dusts collected from swine confinement buildings. [Verticillium sp. ; Actinomycetes

    SciTech Connect

    Donham, K.J.; Scallon, L.J.; Popendorf, W.; Treauhaft, M.W.; Roberts, R.D.

    1986-07-01

    The air in 21 different swine confinement buildings was sampled with 37 mm cassette filters with and without cyclone preselectors and with cascade impactors. Filter results yielded a mean total aerosol of 6.3 mg/m/sup 3/, a mean respirable aerosol of 0.5 mg/m/sup 3/; the geometric mean diameter was 2.9 microns. Cascade impactor measurements revealed a mean total aerosol of 7.6 mg/m/sup 3/, a respirable aerosol of 2.5 mg/m/sup 3/ and a mass median diameter of 9.6 microns. The two major constituents in these aerosols were grain particles and dried fecal matter. The grain particles were larger than fecal particles and proportionately more abundant in finishing buildings where 50 kg-100 kg animals are housed. Therefore the respirable fraction was less in finishing buildings than in farrowing and nursery buildings. Culturing of settled dusts yielded six different mold species, with the highest counts for Verticillium sp. (5 x 10/sup 2/ cfu/mg dry dust) grown at 37/sup 0/C. Thermophilic Actinomycetes and both gram negative and gram positive bacteria were isolated.

  2. PRESOLAR GRAINS FROM NOVAE: EVIDENCE FROM NEON AND HELIUM ISOTOPES IN COMET DUST COLLECTIONS

    SciTech Connect

    Pepin, Robert O.; Palma, Russell L.; Gehrz, Robert D.; Starrfield, Sumner

    2011-12-01

    Presolar grains in meteorites and interplanetary dust particles carry non-solar isotopic signatures pointing to origins in supernovae, giant stars, and possibly other stellar sources. There have been suggestions that some of these grains condensed in the ejecta of classical nova outbursts, but the evidence is ambiguous. We report neon and helium compositions in particles captured on stratospheric collectors flown to sample materials from comets 26P/Grigg-Skjellerup and 55P/Tempel-Tuttle that point to condensation of their gas carriers in the ejecta of a neon (ONe) nova. The absence of detectable {sup 3}He in these particles indicates space exposure to solar wind irradiation of a few decades at most, consistent with origins in cometary dust streams. Measured {sup 4}He/{sup 20}Ne, {sup 20}Ne/{sup 22}Ne, {sup 21}Ne/{sup 22}Ne, and {sup 20}Ne/{sup 21}Ne isotope ratios, and a low upper limit on {sup 3}He/{sup 4}He, are in accord with calculations of nucleosynthesis in neon nova outbursts. Of these, the uniquely low {sup 4}He/{sup 20}Ne and high {sup 20}Ne/{sup 22}Ne ratios are the most diagnostic, reflecting the large predicted {sup 20}Ne abundances in the ejecta of such novae. The correspondence of measured Ne and He compositions in cometary matter with theoretical predictions is evidence for the presence of presolar grains from novae in the early solar system.

  3. An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Dust in Zhangye China During the Asian Monsoon Year Field Experiment (2008)

    NASA Technical Reports Server (NTRS)

    Hansell, Richard A.; Tsay, Si-Chee; Hsu, N. Christina; Ji, Qiang; Bell, Shaun W.; Holben, Brent N.; Ellsworth, Welton J.; Roush, Ted L.; Zhang, Wu; Huang, J.; Li, Zhanquing; Chen, Hongbin

    2012-01-01

    Tiny suspensions of solid particles or liquid droplets, called aerosols, hover in earth's atmosphere and can be found over just about anywhere including oceans, deserts, vegetated areas, and other global regions. Aerosols come in a variety of sizes, shapes, and compositions which depend on such factors as their origin and how long they have been in the atmosphere (i.e., their residence time). Some of the more common types of aerosols include mineral dust and sea salt which get lifted from the desert and ocean surfaces, respectively by mechanical forces such as strong winds. Depending on their size, aerosols will either fall out gravitationally, as in the case of larger particles, or will remain resident in the atmosphere where they can undergo further change through interactions with other aerosols and cloud particles. Not only do aerosols affect air quality where they pose a health risk, they can also perturb the distribution of radiation in the earth-atmosphere system which can inevitably lead to changes in our climate. One aerosol that has been in the forefront of many recent studies, particularly those examining its radiative effects, is mineral dust. The large spatial coverage of desert source regions and the fact that dust can radiatively interact with such a large part of the electromagnetic spectrum due to its range in particle size, makes it an important aerosol to study. Dust can directly scatter and absorb solar and infrared radiation which can subsequently alter the amount of radiation that would otherwise be present in the absence of dust at any level of the atmosphere like the surface. This is known as radiative forcing. At the surface dust can block incoming solar energy, however at infrared wavelengths, dust acts to partially compensate the solar losses. Evaluating the solar radiative effect of dust aerosols is relatively straightforward due in part to the relatively large signal-to-noise ratio in the measurements. At infrared wavelengths, on the

  4. Granulometry and the content of toxic and potentially toxic elements in vacuum-cleaner collected, indoor dusts of the city of Warsaw.

    PubMed

    Lisiewicz, M; Heimburger, R; Golimowski, J

    2000-12-18

    Twenty-seven sites, together with 23 household dust sample sites, representing the home environment, and four public room dust sample sites, representing working environment (mainly offices) have been described in this paper. The latter were examined to obtain an approximate reference to the home environment data. All the samples were collected between May and July 1997 by a vacuum-cleaner method, in the city of Warsaw, Poland. The granulometry of the dusts was determined by their separation into seven fractions in the range 8-500 microm. The concentrations of Cr, Ni, Cu, Zn, Pb, Br and Fe in the samples were investigated in fractions 8-32, 32-63 and 63-125 microm by the EDXRF technique. The results showed higher concentrations of these elements in finer fractions (8-32 microm). The Pb content in the household dusts was found to be unexpectedly low, ranging from 120 microg g(-1) for the 63-125 microm fraction, up to 210 microg g(-1) for the 8-32 microm fraction. Car exhausts could not be determined clearly as the main source of Pb in the indoor household dusts due to the lack of a Pb-Br intercorrelation. In these dusts, only Cr and Zn showed a remarkably high content of 90-100 and 1020-1070 (microg g(-1)), respectively. In the household dusts, strong intercorrelations were present in the three analysed fractions for the metal pairs: Pb-Zn, Pb-Cu, Fe-Cr, and Cu-Cr (weaker). The working environment rooms showed a higher degree of dustiness by 300%, as compared to the dwellings. The dusts collected in the working environment rooms showed slightly higher concentrations of Ni and by 50-100% higher concentrations of: Cu, Zn, Pb, Br than the analysed household dusts.

  5. Uranium mill ore dust characterization

    SciTech Connect

    Knuth, R.H.; George, A.C.

    1980-11-01

    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 ..mu..m with a median diameter of 11 ..mu..m. The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  6. Mammalian airborne allergens.

    PubMed

    Aalberse, Rob C

    2014-01-01

    Historically, horse dandruff was a favorite allergen source material. Today, however, allergic symptoms due to airborne mammalian allergens are mostly a result of indoor exposure, be it at home, at work or even at school. The relevance of mammalian allergens in relation to the allergenic activity of house dust extract is briefly discussed in the historical context of two other proposed sources of house dust allergenic activity: mites and Maillard-type lysine-sugar conjugates. Mammalian proteins involved in allergic reactions to airborne dust are largely found in only 2 protein families: lipocalins and secretoglobins (Fel d 1-like proteins), with a relatively minor contribution of serum albumins, cystatins and latherins. Both the lipocalin and the secretoglobin family are very complex. In some instances this results in a blurred separation between important and less important allergenic family members. The past 50 years have provided us with much detailed information on the genomic organization and protein structure of many of these allergens. However, the complex family relations, combined with the wide range of post-translational enzymatic and non-enzymatic modifications, make a proper qualitative and quantitative description of the important mammalian indoor airborne allergens still a significant proteomic challenge. PMID:24925404

  7. Deposition Rates and Characterization of Arabian Mineral Dust

    NASA Astrophysics Data System (ADS)

    Puthan Purakkal, J.; Stenchikov, G. L.; Engelbrecht, J. P.

    2015-12-01

    Airborne mineral dust directly and indirectly impacts on global climate, continental and marine biochemistry, human and animal health, agriculture, equipment, and visibility. Annual global dust emissions are poorly known with estimates differing by a factor of at least two. Local dust emission and deposition rates are even less quantified. Dust deposition rate is a key parameter, which helps to constrain the modeled dust budget of the atmosphere. However, dust deposition remains poorly known, due to the limited number of reliable measurements. Simulations and satellite observations suggest that coastal dusts contribute substantially to the total deposition flux into the Red Sea. Starting December 2014, deposition samplers, both the "frisbee" type, and passive samplers for individual particle scanning electron microscopy were deployed at King Abdullah University of Science and Technology (KAUST), along the Red Sea in Saudi Arabia. Sampling periods of one month were adopted. The deposition rates range from 3 g m-2 month-1 for fair weather conditions to 23 g m-2 month-1 for high dust events. The X-ray diffraction (XRD) analyses of deposited dust samples show mineralogical compositions different from any of the parent soils, the former consisting mainly of gypsum, calcite, and smaller amounts of albite, montmorillonite, chlorite, quartz and biotite. The deposited dust samples on the other hand contain more gypsum and less quartz than the previously collected soil samples. This presentation discusses the results from XRD, chemical analysis and SEM-based individual particle analysis of the soils and the deposited dust samples. The monthly dust accumulation rates and their seasonal and spatial variability are compared with the regional model predictions. Data from this study provide an observational basis for validating the regional dust mass balance along the Arabian Red Sea coastal plain.

  8. Tracing geogenic and anthropogenic sources in urban dusts: Insights from lead isotopes

    NASA Astrophysics Data System (ADS)

    Del Rio-Salas, R.; Ruiz, J.; De la O-Villanueva, M.; Valencia-Moreno, M.; Moreno-Rodríguez, V.; Gómez-Alvarez, A.; Grijalva, T.; Mendivil, H.; Paz-Moreno, F.; Meza-Figueroa, D.

    2012-12-01

    Tracing the source of metals in the environment is critical to understanding their pollution level and fate. Geologic materials are an important source of airborne particulate matter, but the contribution of contaminated soil to concentrations of Pb in airborne dust is not yet widely documented. To examine the potential significance of this mechanism, surface soil samples were collected, as well as wind-transported dust trapped at 1 and 2 m height at seven different locations including residential, industrial, high-traffic and rural sites. Samples of dust deposited on roofs from 24 schools were also obtained and analyzed for Pb isotope ratios. Spatial distribution of Pb of airborne and sedimented dust suggests a process dominated by re-suspension/sedimentation, which was controlled by erosion, traffic and topography of the urban area. Anthropogenic lead input in the city grades outward the urban zone toward geogenic values. Our results shows that Pb-isotopic signatures of leaded gasoline are imprinted in dust sedimented on roofs. Considering that leaded-gasoline has not been in use in Mexico since two decades ago, this signature shows not only a Pb-legacy in soil, but also a re-suspension process affecting air column below 3 m in height. The combination of the 207Pb/206Pb data of the surrounding rocks and urban dust, reveal three well-defined zones with remarkable anthropogenic influence, which correspond to the oldest urban sectors. This work highlights the importance of spatial characterization of metals in particles suspended below a height of 3 m of the airborne column, a fact that should be considered to identify exposure paths to humans and the potential risks. Lead isotope signatures allowed the identification of geogenic and anthropogenic emission sources for dust, a matter that deserves consideration in the efforts to control airborne metal emissions.

  9. Macrocyclic-, polycyclic-, and nitro musks in cosmetics, household commodities and indoor dusts collected from Japan: implications for their human exposure.

    PubMed

    Nakata, Haruhiko; Hinosaka, Mari; Yanagimoto, Hayato

    2015-01-01

    This paper reported the occurrence and concentrations of macrocyclic-, polycyclic- and nitro musks in cosmetics and household commodities collected from Japan. The high concentrations and detection frequencies of Musk T, habanolide, and exaltolides were found in commercial products, suggesting their large amounts of production and usage in Japan. Polycyclic musks, HHCB and OTNE, also showed high concentrations in cosmetics and products. The estimated dairy intakes of Musk T and HHCB by the dermal exposure to commercial products were 7.8 and 7.9 μg/kg/day in human, respectively, and perfume and body lotion are dominant exposure sources. We also analyzed synthetic musks in house dusts. Polycyclic musks, HHCB and OTNE, showed high concentrations in samples, but macrocyclic musks were detected only in a few samples, although these types of musks were highly detected in commercial products. This is probably due to easy-degradation of macrocyclic musks in indoor environment. The dairy intakes of HHCB by dust ingestions were 0.22 ng/kg/day in human, which were approximately five orders of magnitudes lower than those of dermal absorption from commercial household commodities.

  10. Collection, Storage and Real-Time Transmission of Housekeeping and Instrument Data Aboard Manned NASA Airborne Science Platforms

    NASA Astrophysics Data System (ADS)

    Van Gilst, D. P.; Sorenson, C. E.

    2011-12-01

    Multi-instrument aircraft-based science campaigns require a baseline level of housekeeping service to record and distribute real time data, including timing signals, aircraft state and air data. As campaigns have become more sophisticated with greater integration between aircraft, ground instrumentation, satellites and forecasters in locations around the world, the scope of the services provided by the facility data systems on NASA's airborne science aircraft have increased to include situational awareness displays, real-time interchange of data between instruments and aircraft, and ingest of data to assist in real-time targeting of flights. As the scope of services has expanded, it has become increasingly important to provide standardized interfaces to experimenters to minimize integration complexity, and to make services sufficiently reliable for mission operations to depend upon them. Within the NASA airborne science program in recent years this has been provided by systems based around the core of the REVEAL/NASDAT system, with additional services including satellite communications, data display and ingest of outside data being provided by a mix of custom and COTS hardware and software. With a strong emphasis on transmission of data over industry standard IP and ethernet based networks, this system has been proven on numerous highly diverse missions on the DC-8 over the last 4 years and is being replicated on other NASA Airborne Science Platforms.

  11. Influence of Asian Dust Particles on Immune Adjuvant Effects and Airway Inflammation in Asthma Model Mice

    PubMed Central

    Kurai, Jun; Watanabe, Masanari; Tomita, Katsuyuki; Yamasaki, Hiroyuki Sano Akira; Shimizu, Eiji

    2014-01-01

    Objective An Asian dust storm (ADS) contains airborne particles that affect conditions such as asthma, but the mechanism of exacerbation is unclear. The objective of this study was to compare immune adjuvant effects and airway inflammation induced by airborne particles collected on ADS days and the original ADS soil (CJ-1 soil) in asthma model mice. Methods Airborne particles were collected on ADS days in western Japan. NC/Nga mice were co-sensitized by intranasal instillation with ADS airborne particles and/or Dermatophagoides farinae (Df), and with CJ-1 soil and/or Df for 5 consecutive days. Df-sensitized mice were stimulated with Df challenge intranasally at 7 days after the last Df sensitization. At 24 hours after challenge, serum allergen specific antibody, differential leukocyte count and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were measured, and airway inflammation was examined histopathologically. Results Co-sensitization with ADS airborne particles and Df increased the neutrophil and eosinophil counts in BALF. Augmentation of airway inflammation was also observed in peribronchiolar and perivascular lung areas. Df-specific serum IgE was significantly elevated by ADS airborne particles, but not by CJ-1 soil. Levels of interleukin (IL)-5, IL-13, IL-6, and macrophage inflammatory protein-2 were higher in BALF in mice treated with ADS airborne particles. Conclusion These results suggest that substances attached to ADS airborne particles that are not in the original ADS soil may play important roles in immune adjuvant effects and airway inflammation. PMID:25386753

  12. Allergies, asthma, and dust

    MedlinePlus

    ... much dust. Dust particles collect in fabrics and carpets. If you can, get rid of fabric or ... are covered in cloth. Replace wall-to-wall carpet with wood or other hard flooring. Since mattresses, ...

  13. An assessment of the surface longwave direct radiative effect of airborne dust in Zhangye, China, during the Asian Monsoon Years field experiment (2008)

    NASA Astrophysics Data System (ADS)

    Hansell, Richard A.; Tsay, Si-Chee; Hsu, N. Christina; Ji, Qiang; Bell, Shaun W.; Holben, Brent N.; Welton, Ellsworth J.; Roush, Ted L.; Zhang, W.; Huang, J.; Li, Zhanqing; Chen, H.

    2012-08-01

    In April-June 2008, NASA Goddard's ground-based mobile laboratories (SMART-COMMIT) were deployed to Zhangye China (39.0°N; 101°W) to support the Asian Monsoon Years field experiment and the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate. One of the primary objectives at Zhangye, a semi-arid region located between the Taklimakan and Gobi Deserts, was to capture and characterize dust aerosols near the source and to quantify their direct radiative effects (DRE). A regional dust optical model was constructed by combining previously measured soil mineralogy data at Zhangye with COMMIT's particle microphysical measurements. During a 2-week period of heightened dust activity, retrieved longwave (LW) aerosol optical thickness (τ) from SMART's Atmospheric Emitted Radiance Interferometer was used in the Fu-Liou radiative transfer model to derive LW instantaneous DRE (DRELW) at the surface, top of atmosphere, and heating rate profiles for cloud-free conditions. Conservatively, surface instantaneous DRELW and LW forcing efficiency range from about 2-20 Wm-2 and 31-35 Wm-2τ-1 (0 ≤ τ ≤ 0.83), respectively. The significance of DRELWrelative to its shortwave counterpart was estimated to be between 51 and 58%, but of opposite sign, partly compensating shortwave surface cooling. Compared to Saharan dust observed during the NAMMA-2006 field experiment at Cape Verde, dust LW forcing efficiency for this study was found to be a factor of two larger stemming from differences in environmental and surface conditions, aerosol absorption, and Zhangye's close proximity to major desert sources. Relative to observed and modeled ranges in surface DRELW for clouds (˜30-80 Wm-2) and greenhouse gases (˜2 Wm-2), this study's upper range in DRELW represents a significant perturbation to the climate system with important implications for better understanding regional changes in surface temperatures and moisture budgets.

  14. Modeling of dust deposition in central Asia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The deposition of dust particles has a significant influence on the global bio-geochemical cycle. Currently, the lack of spatiotemporal data creates great uncertainty in estimating the global dust budget. To improve our understanding of the fate, transport and cycling of airborne dust, there is a ne...

  15. Use of electrostatic dust cloth for self-administered home allergen collection

    EPA Science Inventory

    Abstract Most epidemiologic studies employ a vacuum cleaner used by a trained technician to collect household allergens. This approach is labor intensive, equipment dependent, and impractical if study subjects reside over a wide geographic area. We examined the feasibility of a s...

  16. Exposure to airborne microorganisms and endotoxin in herb processing plants.

    PubMed

    Dutkiewicz, J; Krysińska-Traczyk, E; Skórska, C; Sitkowska, J; Prazmo, Z; Golec, M

    2001-01-01

    Microbiological air sampling was performed in two herb processing plants located in eastern Poland. Air samples for determination of the levels of bacteria, fungi, dust and endotoxin were collected at 14 sites during cleaning, cutting, grinding, sieving, sorting and packing of 11 kinds of herbs (nettle, caraway, birch, celandine, marjoram, mint, peppermint, sage, St. John's wort, calamus, yarrow), used for production of medications, cosmetics and spices. It was found that processing of herbs was associated with a very high pollution of the air with bacteria, fungi, dust and endotoxin. The numbers of microorganisms (bacteria and fungi) in the air of herb processing plants ranged within 40.6-627.4 x 10(3) cfu/m3 (mean +/- S.D = 231.4 +/- 181.0 x 10(3) cfu/m3). The greatest concentrations were noted at the initial stages of production cycle, during cleaning, cutting and grinding of herbs. The numbers of airborne microorganisms were also significantly (p<0.0001) related to the kind of processed herb, being the greatest at processing marjoram, nettle, yarrow and mint. The values of the respirable fraction of airborne microflora in the examined facilities varied within a fairly wide range and were between 14.7-67.7%. The dominant microorganisms in the air of herb processing plants were mesophilic bacteria, among which endospore-forming bacilli (Bacillus spp.) and actinomycetes of the species Streptomyces albus were most numerous. Among Gram-negative bacteria, the most common was endotoxin-producing species Alcaligenes faecalis. Altogether, 37 species or genera of bacteria and 23 species or genera of fungi were identified in the air of herb processing plants, of these, 11 and 10 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of dust and bacterial endotoxin in the air of herb processing plants were large with extremely high levels at some sampling sites. The concentrations of airborne dust ranged within 3

  17. Exposure to airborne microorganisms and endotoxin in herb processing plants.

    PubMed

    Dutkiewicz, J; Krysińska-Traczyk, E; Skórska, C; Sitkowska, J; Prazmo, Z; Golec, M

    2001-01-01

    Microbiological air sampling was performed in two herb processing plants located in eastern Poland. Air samples for determination of the levels of bacteria, fungi, dust and endotoxin were collected at 14 sites during cleaning, cutting, grinding, sieving, sorting and packing of 11 kinds of herbs (nettle, caraway, birch, celandine, marjoram, mint, peppermint, sage, St. John's wort, calamus, yarrow), used for production of medications, cosmetics and spices. It was found that processing of herbs was associated with a very high pollution of the air with bacteria, fungi, dust and endotoxin. The numbers of microorganisms (bacteria and fungi) in the air of herb processing plants ranged within 40.6-627.4 x 10(3) cfu/m3 (mean +/- S.D = 231.4 +/- 181.0 x 10(3) cfu/m3). The greatest concentrations were noted at the initial stages of production cycle, during cleaning, cutting and grinding of herbs. The numbers of airborne microorganisms were also significantly (p<0.0001) related to the kind of processed herb, being the greatest at processing marjoram, nettle, yarrow and mint. The values of the respirable fraction of airborne microflora in the examined facilities varied within a fairly wide range and were between 14.7-67.7%. The dominant microorganisms in the air of herb processing plants were mesophilic bacteria, among which endospore-forming bacilli (Bacillus spp.) and actinomycetes of the species Streptomyces albus were most numerous. Among Gram-negative bacteria, the most common was endotoxin-producing species Alcaligenes faecalis. Altogether, 37 species or genera of bacteria and 23 species or genera of fungi were identified in the air of herb processing plants, of these, 11 and 10 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of dust and bacterial endotoxin in the air of herb processing plants were large with extremely high levels at some sampling sites. The concentrations of airborne dust ranged within 3

  18. Polycyclic aromatic hydrocarbons in deposited bedroom dust collected from Xinxiang, a fast developing city in North China.

    PubMed

    Yang, Zhong-Zhi; Li, Yong-Fang; Fan, Jing

    2015-01-01

    To investigate the contamination levels of polycyclic aromatic hydrocarbons (PAHs) in the indoor environment, 16 PAHs were measured in 20 deposited bedroom dust (DBD) samples collected from four residential areas in Xinxiang City. The total PAH concentrations (∑PAHs, defined as the sum of 16 PAHs) in 20 DBD samples ranged from 1.47 to 21.8 μg/g dry weight. PAH ratios indicated that main sources of PAHs in most DBD samples were coal, grasses, and wood combustion. Correlation analysis showed that there were no significant positive correlations between ∑PAH concentrations in DBD and the number of family members or duration of residence. Analysis using the t test revealed that tobacco smoke was a source of PAHs in DBD and that an unattached kitchen may be a significant influencing factor related to PAHs in DBD collected from residential areas in Xinxiang City. Our results showed that the kitchen exhaust fan or hood had no significant influence on total PAHs in DBD, and there was no significant difference in ∑PAH concentrations in DBD in homes which used liquefied petroleum gas and those which used natural gas.

  19. Polycyclic aromatic hydrocarbons in deposited bedroom dust collected from Xinxiang, a fast developing city in North China.

    PubMed

    Yang, Zhong-Zhi; Li, Yong-Fang; Fan, Jing

    2015-01-01

    To investigate the contamination levels of polycyclic aromatic hydrocarbons (PAHs) in the indoor environment, 16 PAHs were measured in 20 deposited bedroom dust (DBD) samples collected from four residential areas in Xinxiang City. The total PAH concentrations (∑PAHs, defined as the sum of 16 PAHs) in 20 DBD samples ranged from 1.47 to 21.8 μg/g dry weight. PAH ratios indicated that main sources of PAHs in most DBD samples were coal, grasses, and wood combustion. Correlation analysis showed that there were no significant positive correlations between ∑PAH concentrations in DBD and the number of family members or duration of residence. Analysis using the t test revealed that tobacco smoke was a source of PAHs in DBD and that an unattached kitchen may be a significant influencing factor related to PAHs in DBD collected from residential areas in Xinxiang City. Our results showed that the kitchen exhaust fan or hood had no significant influence on total PAHs in DBD, and there was no significant difference in ∑PAH concentrations in DBD in homes which used liquefied petroleum gas and those which used natural gas. PMID:25404542

  20. [Further development of an apparatus for dust control in the mechanical digging of supporting beams, recesses and pile endings].

    PubMed

    Preat, B

    1982-01-01

    The Zolder Colliery of the N.V. Kempense Steenkolenmijnen is currently developing compact dust collectors for mounting directly on mining machines. In particular, the collectors are to be used with machines working in stable holes, rippings, face ends and in-seam rise headings. The use of these units will provide clean air within the working area and at the same time reduce contamination outbye. In the first section a review of recent dust collector development is presented, followed by a theoretical analysis of particle dynamics and the filtration process. The next section describes trials with prototypes and highlights some of the problems associated with dust deposition within the equipment. The last two sections describe how the Zolder Colliery first realised the benefits dust collection could offer as a means of controlling airborne dust in mechanized in-serum rise headings and why they favour the development of a dust collector for use in stable holes.

  1. An evaluation of total and inhalable samplers for the collection of wood dust in three wood products industries.

    PubMed

    Harper, Martin; Muller, Brian S

    2002-10-01

    In 1998 the American Conference for Governmental Industrial Hygienists (ACGIH) proposed size selective sampling for wood dust based on the inhalable fraction. Thus the proposed threshold limit values (TLVs) require the use of a sampler whose performance matches the inhalable convention. The Institute of Occupational Medicine (IOM) sampler has shown good agreement with the inhalable convention under controlled conditions, and the Button sampler, developed by the University of Cincinnati, has shown reasonable agreement in at least one laboratory study. The Button sampler has not been previously evaluated under wood working conditions, and the IOM has been shown to sample more mass than expected when compared to the standard closed-face cassette, which may be due to the collection of very large particles in wood working environments. Some projectile particles may be > 100 microm aerodynamic diameter and thus outside the range of the convention. Such particles, if present, can bias the estimates of concentration considerably. This study is part of an on-going research focus into selecting the most appropriate inhalable sampler for use in these industries, and to examine the impact of TLV changes. This study compared gravimetric analyses (National Institute of Occupational Safety and Health Method 0500) of side-by-side personal samples using the Button, IOM, and 37 mm closed-face cassette (CFC) under field-use conditions. A total of 51 good sample pairs were collected from three wood products industries involved in the manufacturing of cabinets, furniture, and shutters. Paired t-tests were run on each sample pair using Statistical Package for the Social Sciences (SPSS) version 10. The IOM and the CFC measured statistically different concentrations (p < 0.0005, n = 16). The IOM and Button measured statistically different concentrations (p = 0.020, n = 12). The Button and CFC did not measure statistically different concentrations of wood dust (p = 0.098, n = 23). Sampler

  2. An evidential example of airborne bacteria in a crowded, underground public concourse in Tokyo

    NASA Astrophysics Data System (ADS)

    Seino, Kaoruko; Takano, Takehito; Nakamura, Keiko; Watanabe, Masafumi

    2005-01-01

    We examined airborne bacteria in an underground concourse in Tokyo and investigated conditions that influenced bacterial counts. Airborne bacteria were collected by using an impactor sampler. Colonies on plate count agar (PCA) and Columbia colistin-nalidixic acid agar with 5% sheep blood (CNA agar) were enumerated. The range, geometric mean, and 95% CI of the bacterial counts (CFU m-3) on PCA and CNA agar were 150-1380, 456, 382-550 and 50-990, 237, 182-309, respectively. Bacterial counts on PCA significantly correlated with number of the pedestrians (r=0.89), relative humidity (r=0.70) and airborne dust (PM5.0) (r=0.73). Results of a multiple regression indicated independent positive association between the number of pedestrians and bacterial counts on PCA (p<0.01) after excluding the influence of relative humidity and airborne dust. Similar results were obtained with the statistical analysis for the counts of bacteria on CNA agar. Gram-positive cocci were dominant on PCA and CNA agar. Staphylococcus epidermidis and Micrococcus spp. were dominant among the 11 genera and 19 species identified in the present study. Considering the pattern of identified species and the significant independent association between number of pedestrians and bacterial counts, airborne bacteria in a crowded underground concourse were mostly originated from the pedestrians who were walking in the underground concourse. This study gave an evidential example of bacterial conditions in the air of an underground crowded public space in Tokyo.

  3. Properties of the size-resolved and individual cloud droplets collected in western Japan during the Asian dust storm event

    NASA Astrophysics Data System (ADS)

    Ma, Chang-Jin; Tohno, Susumu; Kasahara, Mikio; Hayakawa, Shinjiro

    With the point of view of the removal mechanism of Asian dust storm particles, in order to study the physiochemical properties of clouds a field campaign was conducted in western Japan during the Asian dust storm event. The polymeric water absorbent film and collodion film replication techniques were employed in the measurements of size-fractionated precipitation cloud and individual cloud droplets, respectively. In addition, to investigate the source profiles of the elements retained in cloud samples, the original desert sand was collected. Particle-induced X-ray emission was applied for the elemental analysis of size-resolved cloud droplets and desert sand. Also for the quantification analysis of the ultra trace elements in residual particles in individual cloud droplets, the X-ray microprobe system equipped at Super Photon ring-8 GeV (SPring-8) BL-37XU was newly applied. Soil derived components like Si, Ca, and Fe show higher mass concentrations in small droplets (<6.4 μm) than in large droplets (>6.4 μm), while S and Cl dominate at droplet size larger than 20 μm. Three cloud samples have liquid water content ranging from 0.04 to 0.11 g m -3. The number size distribution of droplets collected at cloud base is monomodal with the maximum level around 15 μm. The size distribution of cloud droplets is widespread (up to 60 μm). The droplet residues mainly consisting of crustal components were successively reconstructed as elemental maps by the X-ray fluorescence (XRF) microprobe analytical technique. From these XRF elemental maps, it can be understood that crustal components are significantly distributed on and/or in the residual particles in individual cloud droplets. The plotting of enrichment factors calculated from the elemental composition of original desert sand in China not only indicates the good correlationship between elemental masses in residual particles of cloud base droplets and those of precipitation cloud, but also classify elements into soil

  4. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Determination of dust concentration....

  5. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  6. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  7. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Determination of dust concentration. 33.32... MINES Test Requirements § 33.32 Determination of dust concentration. (a) Concentrations of airborne dust... microscopic technique shall be employed in determining concentrations of dust in terms of millions...

  8. Effect of electrostatic space charge on reduction of airborne transmission of Salmonella and other bacteria in broiler breeders in production and their progeny.

    PubMed

    Richardson, L J; Hofacre, C L; Mitchell, B W; Wilson, J L

    2003-01-01

    Salmonella in birds is a concern because of the human foodborne illness associated with the consumption of poultry meat and eggs. One of the methods of transmission of Salmonella within a flock can be by the air. Therefore, we used reduction of transmission of Salmonella to monitor the effectiveness of the electrostatic space charge system (ESCS). During the average broiler breeder laying cycle of 40 wk, a large amount of dust becomes airborne and accumulates on walls, ceiling, and equipment. Many microorganisms adhere to these dust particles, making dust an excellent vector for horizontal disease transmission between birds. We used two environmentally controlled rooms containing commercial broiler breeders to evaluate the effectiveness of an ESCS that produced a strong negative electrostatic charge to reduce airborne dust and, subsequently, microorganism levels. The ESCS caused the dust to become negatively charged, therefore moving to the grounded floor in the treatment room. The use of the ESCS resulted in a significant reduction (P < 0.0001, 61% reduction) in airborne dust concentration levels, which resulted in a significant reduction (P < 0.0001, 76% reduction) in total airborne bacteria and gram-negative bacteria (48% reduction) in the treatment room. Significant reductions (P < 0.05) of gram-negative bacteria (63% reduction) on the egg collection belts were also recorded in the treatment room, which resulted in a significant reduction (P < 0.0001) of gram-negative bacteria (28% reduction) on the eggshell surface. The ESCS treatment resulted in fewer Salmonella enteritidis-positive hens and their progeny from the treatment room due to reductions of dust and airborne bacteria. In addition, this significant reduction in bacteria on the eggshell surface should result in less bacteria in the day-old chicks, therefore better early chick livability. There was no significant difference (P > 0.05) in egg production, male or female body weights, mortality, or

  9. Relations Between Cloud Condensation Nuclei And Aerosol Optical Properties Relevant to Remote Sensing: Airborne Measurements in Biomass Burning, Pollution and Dust Aerosol Over North America

    NASA Astrophysics Data System (ADS)

    Shinozuka, Y.; Clarke, A.; Howell, S.; Kapustin, V.; McNaughton, C.; Zhou, J.; Decarlo, P.; Jimenez, J.; Roberts, G.; Tomlinson, J.; Collins, D.

    2008-12-01

    Remote sensing of the concentration of cloud condensation nuclei (CCN) would help investigate the indirect effect of tropospheric aerosols on clouds and climate. In order to assess its feasibility, this paper evaluates the spectral-based retrieval technique for aerosol number and seeks one for aerosol solubility, using in-situ aircraft measurements of aerosol size distribution, chemical composition, hygroscopicity, CCN activity and optical properties. Our statistical analysis reveals that the CCN concentration over Mexico can be optically determined to a relative error of <20%, smaller than that for the mainland US and the surrounding oceans (~a factor of 2). Mexico's advantage is four-fold. Firstly, many particles originating from the lightly regulated industrial combustion and biomass burning are large enough to significantly affect light extinction, elevating the correlation between extinction and CCN number in absence of substantial dust. Secondly, the generally low ambient humidity near the major aerosol sources limits the error in the estimated response of particle extinction to humidity changes. Thirdly, because many CCN contain black carbon, light absorption also provides a measure of the CCN concentration. Fourthly, the organic fraction of volatile mass of submicron particles (OMF) is anti-correlated with the wavelength dependence of extinction due to preferential anion uptake by coarse dust, which provides a potential tool for remote-sensing OMF and the particle solubility.

  10. Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler.

    PubMed Central

    Colt, J S

    1998-01-01

    Epidemiologic studies of the association between residential pesticide use and cancer risk require an assessment of past pesticide exposures. Pesticide levels in carpet dust are believed to reflect long-term pesticide use. Recent epidemiologic studies have found collection of dust samples using the high-volume surface sampler (HVS3) to be expensive and cumbersome. We compared the levels of pesticides and other compounds in dust obtained from subjects' personal used vacuum cleaner bags to that collected by the HVS3 to see if this simpler method could replace the HVS3 in epidemiologic research. We visited the homes of 15 subjects, took the used bags from their vacuums, and collected carpet dust samples with the HVS3. The samples were analyzed for 42 target compounds: 26 pesticides, 10 polycyclic aromatic hydrocarbons (PAHs), and six polychlorinated biphenyl (PCB) congeners using GC/MS in selected ion monitoring mode. The two methods agreed in detecting the presence of the target compounds between 80% and 100% of the time. Neither sampling method was consistently more sensitive. The median target compound concentrations were similar, and a paired t-test showed no significant differences. For many compounds, the concentrations of compounds in the HVS3 samples were higher than those in the used bag samples at the upper end of the concentration ranges. However, the Spearman rank correlation coefficients were 0.85 or higher for most compounds, indicating that homes would be ranked similarly using both methods. Overall, there appears to be no clear difference in the quality of the pesticide, PAH, or PCB concentration data for the two dust collection methods. Images Figure 1 PMID:9799187

  11. Genotypic and phenotypic characterization of aerosolized bacteria collected from African dust events

    DOE PAGES

    Wilson, Christina A.; Brigmon, Robin L.; Yeager, Chris; Smith, Garriet W.; Polson, Shawn W.

    2013-07-31

    Twenty-one bacteria were isolated and characterized from air samples collected in Africa and the Caribbean by the United States Geological Survey (USGS). Isolates were selected based on preliminary characterization as possible pathogens. Identification of the bacterial isolates was 25 achieved using 16S rRNA gene sequence analysis, fatty acid methyl esters (FAMEs) profiling, the BIOLOG Microlog® System (carbon substrate assay), and repetitive extragenic palindromic (REP)-PCR analysis. The majority of isolates (18/21) were identified as species of the genus Bacillus. Three isolates were classified within the Bacillus cereus senso lato group, which includes Bacillus anthracis, Bacillus thuringiensis, and Bacillus cereus strains. Onemore » isolate was identified as a Staphylococcus sp., 30 most closely related to species (i.e Staphylococcus kloosii, Staphylococcus warneri) that are commonly associated with human or animal skin, but can also act as opportunistic pathogen. Another isolate was tentatively identified as Tsukamurella inchonensis, a known respiratory pathogen, and was resistant to the ten antibiotics tested including vancomycin.« less

  12. Genotypic and phenotypic characterization of aerosolized bacteria collected from African dust events

    SciTech Connect

    Wilson, Christina A.; Brigmon, Robin L.; Yeager, Chris; Smith, Garriet W.; Polson, Shawn W.

    2013-07-31

    Twenty-one bacteria were isolated and characterized from air samples collected in Africa and the Caribbean by the United States Geological Survey (USGS). Isolates were selected based on preliminary characterization as possible pathogens. Identification of the bacterial isolates was 25 achieved using 16S rRNA gene sequence analysis, fatty acid methyl esters (FAMEs) profiling, the BIOLOG Microlog® System (carbon substrate assay), and repetitive extragenic palindromic (REP)-PCR analysis. The majority of isolates (18/21) were identified as species of the genus Bacillus. Three isolates were classified within the Bacillus cereus senso lato group, which includes Bacillus anthracis, Bacillus thuringiensis, and Bacillus cereus strains. One isolate was identified as a Staphylococcus sp., 30 most closely related to species (i.e Staphylococcus kloosii, Staphylococcus warneri) that are commonly associated with human or animal skin, but can also act as opportunistic pathogen. Another isolate was tentatively identified as Tsukamurella inchonensis, a known respiratory pathogen, and was resistant to the ten antibiotics tested including vancomycin.

  13. Spirosoma pulveris sp. nov., a bacterium isolated from a dust sample collected at Chungnam province, South Korea.

    PubMed

    Joo, Eun Sun; Lee, Jae-Jin; Cha, Seho; Jheong, Weonhwa; Seo, Taegun; Lim, Sangyong; Jeong, Sun-Wook; Srinivasan, Sathiyaraj

    2015-11-01

    Strain JSH 5-14(T), a Gram-negative, non-motile, and curved rod-shaped bacterium, was isolated from a dust sample collected at Nonsan, Chungnam province, South Korea, and was characterized to determine its taxonomic position. Phylogenetic analysis based on the 16S rRNA gene sequence of strain JSH 5-14(T) revealed that it belongs to the genus Spirosoma, family Cytophagaceae, class Cytophagia. The highest degree of sequence similarities of strain JSH 5-14(T) were found with Spirosoma liguale DSM 74(T) (97.8%) and Spirosoma endophyticum EX 36(T) (96.2%). The predominant fatty acids were summed feature 3 (composed of C16:1 ω7c/C16:1 ω6c) and C16:1 ω5c. The major polar lipid was phosphatidylethanolamine, and the predominant respiratory quinone was MK-7. Based on the phylogenetic, chemotaxonomic, and phenotypic data, we propose the strain JSH 5-14(T) (=KCTC 42550(T) =JCM 30688(T) =KEMB 9004-165(T)) should be classified as a type strain of a novel species, for which the name Spirosoma pulveris sp. nov., is proposed. PMID:26502958

  14. Levels of fungi and mycotoxins in the samples of grain and grain dust collected from five various cereal crops in eastern Poland.

    PubMed

    Krysińska-Traczyk, Ewa; Perkowski, Juliusz; Dutkiewicz, Jacek

    2007-01-01

    During combine harvesting of 5 various cereal crops (rye, barley, oats, buckwheat, corn) 24 samples of grain and 24 samples of settled grain dust were collected on farms located in the Lublin province of eastern Poland. The samples were examined for the concentration of total microfungi, Fusarium species, deoxynivalenol (DON), nivalenol (NIV), and ochratoxin A (OTA). Microfungi able to grow on malt agar were present in 79.2% of grain samples and in 91.7% of grain dust samples in the concentrations of 1.0-801.3x10(3) cfu/g and 1.5-12440.0x10(3) cfu/g, respectively. The concentration of microfungi in grain dust samples was significantly greater than in grain samples (p<0.01). Fusarium strains were isolated from 54.2% of grain samples and from 58.3% of grain dust samples in the concentrations of 0.1-375.0x10(3) cfu/g and 4.0-7,700.0x10(3) cfu/g, respectively. They were found in all samples of grain and grain dust from rye, barley and corn, but only in 0-16.7% of samples of grain and grain dust from oats and buckwheat. DON was found in 79.2% of grain samples and in 100% of grain dust samples in the concentrations of 0.001-0.18 microg/g and 0.006-0.283 microg/g, respectively. NIV was detected in 62.5% of grain samples and in 94.4% of grain dust samples in the concentrations of 0.004-0.502 microg/g and 0.005-0.339 microg/g, respectively. OTA was detected in 58.3% of grain samples and in 91.7% of grain dust samples in the concentrations of 0.00039- 0.00195 microg/g and 0.00036-0.00285 microg/g, respectively. The concentrations of DON, total fusariotoxins (DON+NIV) and OTA were significantly greater in grain dust samples than in grain samples (p<0.05, p<0.05, and p<0.001, respectively). The concentration of Fusarium poae in the samples of rye grain and dust was significantly correlated with the concentrations of DON (p<0.05), NIV (p<0.01), and total fusariotoxins (p<0.05). Similarly, the concentration of Fusarium culmorum in the samples of barley grain and dust was

  15. Concentration and distribution of platinum group elements (Pt, Pd, Rh) in airborne particulate matter in Frankfurt am Main, Germany.

    PubMed

    Zereini, Fathi; Alt, Friedrich; Messerschmidt, Jürge; von Bohlen, Alex; Liebl, Karlheinz; Püttmann, Wilhelm

    2004-03-15

    The concentrations and distribution of platinum group elements (Pt, Pd, Rh) in airborne particulate matter were studied in a period of one year from August 2001 to July 2002 in urban and in nonurban areas. Airborne dust samples were collected as a total amount (particles with an aerodynamic diameter <22 microm) and classified using an eight-stage Andersen impactor (<10 microm) at three locations with different traffic density roads in the Frankfurt am Main and nonurban areas. Sampling at the three locations was performed simultaneously for total airborne dust and fractionated airborne dust. Pd was determined by total reflection X-ray fluorescence after Hg coprecipitation. Pt and Rh were analyzed by adsorptive striping voltammetry after HPA digestion. The results show that the PGE concentrations in airborne samples depend on the traffic density. The highest PGE concentrations in air were found in the vicinity of major roads with heavy traffic, and the lowest ones were found in the nonurban area. The presence of PGE at the sampling station relatively free of traffic in a nonurban area hints to a transport of some of the emitted PGE from the city to this station by wind. At all three sampling locations, a heterogeneous distribution of the Pd, Pt, and Rh concentrations during the sampling year can be observed. The sum of PGE concentrations in total airborne dust is comparable with the sum of impactor samples. However, the concentration of Pt and Rh in total airborne dust (<22 microm) is on average higher than in impactor samples (<10 microm). On the contrary, Pd concentration is higher in impactor samples in most cases. The airborne PGE distribution is dominated by Pt, followed by Pd and Rh. The impactor samples are dominated by Pd, followed by Pt and Rh. This fact indicates that palladium occurs mainly in relatively fine airborne particles. The main fraction of PGE is found on average in particle sizes between 1.1 and 4.7 microm. Knowledge of the size distribution of

  16. Dust, Climate, and Human Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. Ths paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  17. Dust, Climate, and Human Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  18. Dust, Climate, and Human Health

    NASA Astrophysics Data System (ADS)

    Maynard, N. G.

    2003-12-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health

  19. Structure, inter-annual recurrence, and global-scale connectivity of airborne microbial communities.

    PubMed

    Barberán, Albert; Henley, Jessica; Fierer, Noah; Casamayor, Emilio O

    2014-07-15

    Dust coming from the large deserts on Earth, such as the Sahara, can travel long distances and be dispersed over thousands of square kilometers. Remote dust deposition rates are increasing as a consequence of global change and may represent a mechanism for intercontinental microbial dispersal. Remote oligotrophic alpine lakes are particularly sensitive to dust inputs and can serve as sentinels of airborne microbial transport and the ecological consequences of accelerated intercontinental microbial migration. In this study, we applied high-throughput sequencing techniques (16S rRNA amplicon pyrosequencing) to characterize the microbial communities of atmospheric deposition collected in the Central Pyrenees (NE Spain) along three years. Additionally, bacteria from soils in Mauritania and from the air-water interface of high altitude Pyrenean lakes were also examined. Communities in aerosol deposition varied in time with a strong seasonal component of interannual similarity. Communities from the same season tended to resemble more each other than those from different seasons. Samples from disparate dates, in turn, slightly tended to have more dissimilar microbial assemblages (i.e., temporal distance decay), overall suggesting that atmospheric deposition may influence sink habitats in a temporally predictable manner. The three habitats examined (soil, deposition, and air-water interface) harbored distinct microbial communities, although airborne samples collected in the Pyrenees during Saharan dust outbreaks were closer to Mauritian soil samples than those collected during no Saharan dust episodes. The three habitats shared c.a. 1.4% of the total number of microbial sequences in the dataset. Such successful immigrants were spread in different bacterial classes. Overall, this study suggests that local and regional features may generate global trends in the dynamics and distribution of airborne microbial assemblages, and that the diversity of viable cells in the high

  20. Characterization of endotoxin and 3-hydroxy fatty acid levels in air and settled dust from commercial aircraft cabins.

    PubMed

    Hines, C J; Waters, M A; Larsson, L; Petersen, M R; Saraf, A; Milton, D K

    2003-06-01

    Endotoxin was measured in air and dust samples collected during four commercial aircraft flights. Samples were analyzed for endotoxin biological activity using the Limulus assay. 3-hydroxy fatty acids (3-OH FA) of carbon chain lengths C10:0-C18:0 were determined in dust by gas chromatography-ion trap tandem mass spectrometry. The geometric mean (geometric standard deviation) endotoxin air level was 1.5 EU/m3 (1.9, n = 28); however, significant differences were found by flight within aircraft type. Mean endotoxin levels were significantly higher in carpet dust than in seat dust (140 +/- 81 vs. 51 +/- 25 EU/mg dust, n = 32 each, P < 0.001). Airborne endotoxin levels were not significantly related to either carpet or seat dust endotoxin levels. Mean 3-OH FA levels were significantly higher in carpet dust than in seat dust for C10:2, C12:0, and C14:0 (P < 0.001 for each), while the mean level of C16:0 was significantly higher in seat dust than in carpet dust (P < 0.01). Carpet dust endotoxin was significantly, but moderately, correlated with 3-OH-C12:0 and 3-OH-C14:0 (Pearson r = 0.52 and 0.48, respectively), while correlation of seat dust endotoxin with individual 3-OH FAs depended on the test statistic used. Mean endotoxin potency was significantly higher for carpet dust than for seat dust (6.3 +/- 3.0 vs. 3.0 +/- 1.4 EU/pmol LPS, P < 0.0001). Mean endotoxin levels in the air and dust of commercial aircraft cabins were generally higher than mean levels reported in homes and office buildings. These results suggest that exposure route and dust source are important considerations when relating endotoxin exposure to specific health outcomes.

  1. Source Identification Of Airborne Antimony On The Basis Of The Field Monitoring And The Source Profiling

    NASA Astrophysics Data System (ADS)

    Iijima, A.; Sato, K.; Fujitani, Y.; Fujimori, E.; Tanabe, K.; Ohara, T.; Shimoda, M.; Kozawa, K.; Furuta, N.

    2008-12-01

    The results of the long-term monitoring of airborne particulate matter (APM) in Tokyo indicated that APM have been extremely enriched with antimony (Sb) compared to crustal composition. This observation suggests that the airborne Sb is distinctly derived from human activities. According to the material flow analysis, automotive brake abrasion dust and fly ash from waste incinerator were suspected as the significant Sb sources. To clarify the emission sources of the airborne Sb, elemental composition, particle size distribution, and morphological profiles of dust particles collected from two possible emission sources were characterized and compared to the field observation data. Brake abrasion dust samples were generated by using a brake dynamometer. During the abrasion test, particle size distribution was measured by an aerodynamic particle sizer spectrometer. Concurrently, size- classified dust particles were collected by an Andersen type air sampler. Fly ash samples were collected from several municipal waste incinerators, and the bulk ash samples were re-dispersed into an enclosed chamber. The measurement of particle size distribution and the collection of size-classified ash particles were conducted by the same methodologies as described previously. Field observations of APM were performed at a roadside site and a residential site by using an Andersen type air sampler. Chemical analyses of metallic elements were performed by an inductively coupled plasma atomic emission spectrometry and an inductively coupled plasma mass spectrometr. Morphological profiling of the individual particle was conducted by a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. High concentration of Sb was detected from both of two possible sources. Particularly, Sb concentrations in a brake abrasion dust were extremely high compared to that in an ambient APM, suggesting that airborne Sb observed at the roadside might have been largely derived from

  2. Determination of rare earth elements (REES) in airborne particulate matter (APM) collected in Tokyo, Japan, and a positive anomaly of europium and terbium.

    PubMed

    Suzuki, Yoshinari; Suzuki, Tatsunosuke; Furuta, Naoki

    2010-01-01

    The determination of rare earth elements (REEs) in airborne particulate matter (APM) was conducted, and the distribution pattern of atmospheric REEs was evaluated in this study. The APM was collected in the center of Tokyo, Japan, where serious air pollution is always of concern. A cellulose acetate membrane filter was used to collect the APM because Ba and REEs contamination is lower than that in a quartz glass fiber filter. The REEs measurement was conducted by ICP-MS after the digestion of the APM by a microwave acid digestion procedure. The standard reference material (SRM) of NIST 1648 urban particulate matter was used to validate the accuracy of the analytical method. The analytical results for SRM well agreed with those of the reference and reported values. Consequently, the analytical method established in this study was applied to the determination of REEs in APM collected in Tokyo, Japan. The obtained REEs distribution pattern in the APM showed a positive anomaly of Tb and Eu. The La/Sm ratio, which is considered to be as a good indicator of the anthropogenic effect, in size-classified APM showed a high degree of the anthropogenic effect in fine APM with a diameter of <1.1 µm. Emission sources of Tb, Eu and other REEs are discussed.

  3. Typology of dust particles collected by the COSIMA mass spectrometer in the inner coma of 67P/Churyumov Gerasimenko from Rendez-Vous to perihelion.

    NASA Astrophysics Data System (ADS)

    Langevin, Y.; Hilchenbach, M.; Ligier, N.; Merouhane, S.; Hornung, K.

    2015-10-01

    COSIMA is a TOF/SIMS spectrometer dedicated to the analysis of cometary grains collected insitu on the the Rosetta orbiter. The grains are collected on targets 10 mm x 10 mm in area exposed by sets of 3("target assembly") in front of a funnel providing a 20° x 40° FOV to the outside environment of the spacecraft. 4 target assemblies have been exposed from August 8th 2014 (distant approach phase) to April 29th, 2015 on a weekly basis, except during near comet passages (daily basis). 10 of the 12 targets exposed up to now are covered by "metal black" layers (gold or silver) so as to maximize grain collection efficiency [1], the other two targets being silver foils. The collected grains are detected by a microscope, COSISCOPE, using two LED's at grazing incidence and a 14 μm pixel size (714 pixels across the target). This set up was designed so as not to miss the small particles expected to dominate the distribution of collected dust as well as the imprints resulting from rebounding particles when simulating impacts at speeds of up to 300 m/s as predicted by models of the inner coma [2]. The number and size of collected particles far exceeded expectations, with more than 10000 identified particles, including more than 80 collected dust particles with sizes of 7 pixels (100 μm) or more, making it possible to characterize the diversity of cometary grains collected in-situ at very low velocities in the inner coma of 67P/Churyumov-Gerasimenko. The first results demonstrated that cometary dust close to the nucleus is dominated by fluffy aggregates [3]. At EPSC, we will present the results on the pre-perihelion phase (August 2014 to August 2015).

  4. Simultaneous determination of airborne carbonyls and aromatic hydrocarbons using mixed sorbent collection and thermal desorption-gas chromatography/mass spectrometric analysis.

    PubMed

    Chien, Yeh-Chung; Yin, Ko-Ghun

    2009-05-01

    Volatile organic chemicals (VOC) such as aromatics and carbonyls are ubiquitous, and have environmental and health significance. This work presents a novel analytical method for simultaneously monitoring airborne carbonyls compounds and aromatic hydrocarbons. Carbonyls were collected onto an adsorbent (Tenax TA, coated with pentafluorophenyl hydrazine (PFPH)) that reacted with carbonyl groups to form thermo-stable derivatives that are suitable for subsequent analysis by thermal-desorption and GC/MS. Aromatic hydrocarbons were collected onto Tenax TA that was packed in the same sampling tube, and analyzed using the same method as carbonyls. Six carbonyls (formaldehyde, acetaldehyde, benzaldehyde, acetone, methyl ethyl ketone and methyl isobutyl ketone) and five aromatics (benzene, toluene, ethylbenzene, xylenes and styrene) were evaluated following standard test protocols. Calibration ranges were 30-200 ng per tube for most test chemicals, and 200-1000 ng per tube for formaldehyde. The analytical precision was 7% or better, and the collection efficiency, tested using a static sampling bag, was between 94 and 98%. PFPH-coated Tenax TA (for collecting carbonyls) needs to be placed in the front section of the tube, and Tenax TA in the back section (for collecting aromatics). The method detection limits of the current method ranged between 0.2 and 25 ng per tube, which corresponded to sub- to 17.2 ppbv (for formaldehyde), based on a typical 6 l sample from a sampling rate of 25 ml/min. Samples were stable for at least ten days under ambient conditions. The proposed method was also tested in the field and proved satisfactory. The proposed method is simple, feasible and has an acceptable accuracy and precision. It can thus be adopted as a reference method for making relevant measurements. PMID:19436859

  5. Airborne Transparencies.

    ERIC Educational Resources Information Center

    Horne, Lois Thommason

    1984-01-01

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

  6. Levoglucosan and Lipid Class Compounds in the Asian Dusts and Marine Aerosols Collected During the ACE-Asia Campaign

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Simoneit, B. R.; Kawamura, K.; Mochida, M.; Lee, M.; Lee, G.; Huebert, B. J.

    2002-12-01

    In order to characterize organic aerosols in the Asian Pacific region, we collected filter samples at Gosan (formerly Kosan) and Sapporo sites as well as on mobile platforms (R.V. R.H. Brown and NCAR C-130) in the western North Pacific. The aerosol extracts were analyzed by capillary GC-MS employing a TMS derivatization technique. We identified over 100 organic compounds in the samples. They are categorized into seven different classes in terms of functional groups and sources. First, sugar-type compounds were detected in the aerosols, including levoglucosan, galactosan and mannosan, which are tracers for biomass burning. Second, a homologous series of fatty acids (C12-C30) and fatty alcohols (C12-C30) mainly from plant waxes and marine lipids were present. The third group includes dicarboxylic acids (>C3) and other atmospheric oxidation products. Although oxalic (C2) and malonic (C3) acids were not detected by this method, they are very abundant in the aerosols. The fourth group includes n-alkanes (C18-C35) which usually showed a strong odd/even predominance, suggesting an important contribution from higher plant waxes. The fifth includes polynuclear aromatic hydrocarbons (PAH) ranging from phenanthrene to coronene, all combustion products of petroleum and mainly coal. Saccharides were the sixth group and consisted mainly of a- and b- glucose, sucrose and its alditol, and minor amounts of xylitol, sorbitol and arabitol. These saccharides are tracers for soil dust. Phthalates were detected as the seventh class, with a dominance of dioctyl phthalate. The results suggest that organic aerosols originate primarily from (1) natural emissions of terrestrial plant wax and marine lipids, (2) smoke from biomass burning (mainly non-conifer fuels), (3) soil resuspension due to spring agricultural activity, (4) urban/industrial emissions from fossil fuel use (coal), and (5) secondary reaction products. These compounds are transported by the strong westerly winds and therefore

  7. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Specifications and preliminary design of an Airborne Oceanographic Lidar (AOL) system, which is to be constructed for installation and used on a NASA Wallops Flight Center (WFC) C-54 research aircraft, are reported. The AOL system is to provide an airborne facility for use by various government agencies to demonstrate the utility and practicality of hardware of this type in the wide area collection of oceanographic data on an operational basis. System measurement and performance requirements are presented, followed by a description of the conceptual system approach and the considerations attendant to its development. System performance calculations are addressed, and the system specifications and preliminary design are presented and discussed.

  8. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

    Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown.

  9. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

    Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown. PMID:23406937

  10. Dynamic Dust Accumulation and Dust Removal Observed on the Mars Exploration Rover Magnets

    NASA Technical Reports Server (NTRS)

    Bertelsen, P.; Bell, J. F., III; Goetz, W.; Gunnlaugsson, H. P.; Herkenhoff, K. E.; Hviid, S. F.; Johnson, J. R.; Kinch, K. M.; Knudsen, J. M.; Madsen, M. B.

    2005-01-01

    The Mars Exploration Rovers each carry a set of Magnetic Properties Experiments designed to investigate the properties of the airborne dust in the Martian atmosphere. It is a preferred interpretation of previous experiments that the airborne dust in the Martian atmosphere is primarily composed by composite silicate particles containing one or more highly magnetic minerals as a minor constituent. The ultimate goal of the magnetic properties experiments on the Mars Exploration Rover mission is to provide some information/ constraints on whether the dust is formed by volcanic, meteoritic, aqueous, or other processes. The first problem is to identify the magnetic mineral(s) in the airborne dust on Mars. While the overall results of the magnetic properties experiments are presented in, this abstract will focus on dust deposition and dust removal on some of the magnets.

  11. Genotoxicity of Polycyclic Aromatic Hydrocarbons and Nitro-Derived in Respirable Airborne Particulate Matter Collected from Urban Areas of Rio de Janeiro (Brazil)

    PubMed Central

    Ramos de Rainho, Claudia; Machado Corrêa, Sérgio; Luiz Mazzei, José; Alessandra Fortes Aiub, Claudia

    2013-01-01

    Air pollution toxic effects are mainly attributed to small inhalable particulates with an aerodynamic diameter of less than 2.5 µm (PM 2.5). Our objective was to investigate mutagenic and clastogenic activity in PM samples collected in Rio de Janeiro. Samples were collected using a high-volume sampler at three sites: with low traffic and (2) and (3) with a heavy traffic. Six polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography/mass spectrometry (GC/MS). Salmonella typhimurium TA98 and the derivative strains YG1021 and YG1024 were used in mutagenicity assays in the presence of organic extracts (10–50 µg/ plate) with and without exogenous metabolization. Allium cepa test was performed to evaluate possible cytotoxic and clastogenic activities. The highest PM 2.5 µm (132.73 µm/m3) and PAH values (1.22 ng/m3 for benzo(a)pyrene) were detected at site 3. High mutagenic frameshift responses in absence and presence of metabolic activation were detected at site 3. The participation of nitroarenes and dinitroarenes was detected in the total mutagenicity of the extracts studied. The cytotoxic effect and the abnormalities detected by Allium cepa test can be attributed to the PAH nitroderivatives in the organic extracts. Evaluation of the genotoxicity of urban airborne particulate matter is important as a basis for decision making by regulatory authorities. PMID:23738331

  12. Genotoxicity of polycyclic aromatic hydrocarbons and nitro-derived in respirable airborne particulate matter collected from urban areas of Rio de Janeiro (Brazil).

    PubMed

    Ramos de Rainho, Claudia; Machado Corrêa, Sérgio; Luiz Mazzei, José; Alessandra Fortes Aiub, Claudia; Felzenszwalb, Israel

    2013-01-01

    Air pollution toxic effects are mainly attributed to small inhalable particulates with an aerodynamic diameter of less than 2.5 µ m (PM 2.5). Our objective was to investigate mutagenic and clastogenic activity in PM samples collected in Rio de Janeiro. Samples were collected using a high-volume sampler at three sites: with low traffic and (2) and (3) with a heavy traffic. Six polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography/mass spectrometry (GC/MS). Salmonella typhimurium TA98 and the derivative strains YG1021 and YG1024 were used in mutagenicity assays in the presence of organic extracts (10-50 µ g/ plate) with and without exogenous metabolization. Allium cepa test was performed to evaluate possible cytotoxic and clastogenic activities. The highest PM 2.5 µ m (132.73 µ m/m(3)) and PAH values (1.22 ng/m(3) for benzo(a)pyrene) were detected at site 3. High mutagenic frameshift responses in absence and presence of metabolic activation were detected at site 3. The participation of nitroarenes and dinitroarenes was detected in the total mutagenicity of the extracts studied. The cytotoxic effect and the abnormalities detected by Allium cepa test can be attributed to the PAH nitroderivatives in the organic extracts. Evaluation of the genotoxicity of urban airborne particulate matter is important as a basis for decision making by regulatory authorities. PMID:23738331

  13. Risk of Adverse Health and Performance Effects of Celestial Dust Exposure

    NASA Technical Reports Server (NTRS)

    Scully, Robert R.; Meyers, Valerie E.

    2015-01-01

    Crew members can be directly exposed to celestial dust in several ways. After crew members perform extravehicular activities (EVAs), they may introduce into the habitat dust that will have collected on spacesuits and boots. Cleaning of the suits between EVAs and changing of the Environmental Control Life Support System filters are other operations that could result in direct exposure to celestial dusts. In addition, if the spacesuits used in exploration missions abrade the skin, as current EVA suits have, then contact with these wounds would provide a source of exposure. Further, if celestial dusts gain access to a suit's interior, as was the case during the Apollo missions, the dust could serve as an additional source of abrasions or enhance suit-induced injuries. When a crew leaves the surface of a celestial body and returns to microgravity, the dust that is introduced into the return vehicle will "float," thus increasing the opportunity for ocular and respiratory injury. Because the features of the respirable fraction of lunar dusts indicate they could be toxic to humans, NASA conducted several studies utilizing lunar dust simulants and authentic lunar dust to determine the unique properties of lunar dust that affect physiology, assess the dermal and ocular irritancy of the dust, and establish a permissible exposure limit for episodic exposure to airborne lunar dust during missions that would involve no more than 6 months stay on the lunar surface. Studies, with authentic lunar soils from both highland (Apollo 16) and mare (Apollo17) regions demonstrated that the lunar soil is highly abrasive to a high fidelity model of human skin. Studies of lunar dust returned during the Apollo 14 mission from an area of the moon in which the soils were comprised of mineral constituents from both major geological regions (highlands and mares regions) demonstrated only minimal ocular irritancy, and pulmonary toxicity that was less than the highly toxic terrestrial crystalline

  14. Fungal types and concentrations from settled dust in normal residences.

    PubMed

    Hicks, Jeffrey B; Lu, Elizabeth T; De Guzman, Rachel; Weingart, Michal

    2005-10-01

    Analysis of settled dust collected from carpeting and furnishings is occasionally used by investigators to determine whether an environment contains unusual fungi. Little information is available concerning the types and concentrations of culturable fungi present on textile surfaces in normal residential settings not affected by unusual mold reservoirs, such as from fungal growth sites within the built environment. This study presents the results of the collection and analysis of surface dust from 26 residential environments that were prescreened by interview, physical inspection, and air sampling to limit the surface dust collection to structures in which there was no history of water intrusion, flooding, plumbing leaks, signs of mold growth, or evidence of unusual airborne fungal spore types or concentrations. In those structures found to have no history or indications of water events or unusual fungi, surface dust was vacuumed from prescribed horizontal areas on carpet and textile-covered furnishings. These samples were then subjected to fungal culture, from which viable colonies were enumerated and identified. Based on the study results, it does not appear reasonable that the frequently quoted total fungi concentration exceeding 10(5) CFU/g is definitive evidence that a residential surface is contaminated with unusual amounts of culturable fungi. Collocated samples collected from eight side-by-side carpets sections revealed poor reproducibility. While settled dust sampling may be appropriate for determining the fungal status of a localized area, or as a gross screening tool, using settled dust results alone to establish the presence of unusual fungal types or concentrations within a structure appears to be inappropriate, and using settled dust results with other investigative methods, such as visual observations and air sampling, requires cautious interpretation.

  15. Characterizing Dust from Cutting Corian®, a Solid-Surface Composite Material, in a Laboratory Testing System.

    PubMed

    Qi, Chaolong; Echt, Alan; Murata, Taichi K

    2016-06-01

    We conducted a laboratory test to characterize dust from cutting Corian(®), a solid-surface composite material, with a circular saw. Air samples were collected using filters and direct-reading instruments in an automatic laboratory testing system. The average mass concentrations of the total and respirable dusts from the filter samples were 4.78±0.01 and 1.52±0.01mg cm(-3), respectively, suggesting about 31.8% mass of the airborne dust from cutting Corian(®) is respirable. Analysis of the metal elements on the filter samples reveals that aluminum hydroxide is likely the dominant component of the airborne dust from cutting Corian(®), with the total airborne and respirable dusts containing 86.0±6.6 and 82.2±4.1% aluminum hydroxide, respectively. The results from the direct-reading instruments confirm that the airborne dust generated from cutting Corian(®) were mainly from the cutting process with very few particles released from the running circular saw alone. The number-based size distribution of the dusts from cutting Corian(®) had a peak for fine particles at 1.05 µm with an average total concentration of 871.9 particles cm(-3), and another peak for ultrafine particles at 11.8nm with an average total concentration of 1.19×10(6) particles cm(-3) The small size and high concentration of the ultrafine particles suggest additional investigation is needed to study their chemical composition and possible contribution to pulmonary effect.

  16. Small airways involvement in coal mine dust lung disease.

    PubMed

    Long, Joshua; Stansbury, Robert C; Petsonk, Edward L

    2015-06-01

    Inhalation of coal mine dust results in a spectrum of symptoms, dysfunction, and pathological changes in the respiratory tract that collectively have been labeled coal mine dust lung disease. Recent reports from periodic health surveillance among underground and surface coal miners in the United States have demonstrated an increasing prevalence and severity of dust diseases, and have also documented that some miners experience rapid disease progression. The coal macule is an inflammatory lesion associated with deposited dust, and occurs in the region of the most distal conducting airways and proximal respiratory bronchioles. Inflammatory changes in the small airways have long been recognized as the signature lung pathology among coal miners. Human and laboratory studies have suggested oxidant injury, and increased recruitment and activity of macrophages play important roles in dust-induced lung injury. However, the functional importance of the small airway changes was debated for many years. We reviewed published literature that documents a pervasive occurrence of both physiologic and structural abnormalities in small airways among coal miners and other workers exposed to airborne particulates. There is increasing evidence supporting an important association of abnormalities in the small peripheral airways with the development of respiratory symptoms, deficits in spirometry values, and accelerated declines in ventilatory lung function. Pathologic changes associated with mineral dust deposition in the small airways may be of particular importance in contemporary miners with rapidly progressive respiratory impairment.

  17. African desert dust in the Caribbean atmosphere: Microbiology and public health

    USGS Publications Warehouse

    Griffin, Dale W.; Garrison, V.H.; Herman, J.R.; Shinn, E.A.

    2001-01-01

    Air samples collected on St. John in the U.S. Virgin Islands were screened for the presence of viable bacteria and fungi to determine if the number of cultivatable microbes in the atmosphere differed between "clear atmospheric conditions" and "African dust-events." Results indicate that during "African dust-events," the numbers of cultivatable airborne microorganisms can be 2 to 3 times that found during "clear atmospheric conditions." Direct microbial counts of air samples using an epifluorescent microscopy assay demonstrated that during an "African dust-event," bacteria-like and virus-like particle counts were approximately one log greater than during "clear atmospheric conditions." Bacteria-like particles exhibiting autofluoresence, a trait of phototrophs, were only detected during an "African dust-event.".

  18. Size-resolved Chemical Composition of Cloud and Rain Water Collected during the Puerto Rico African Dust and Clouds Study (PRADACS) Campaign

    NASA Astrophysics Data System (ADS)

    Valle Diaz, C. J.; Mayol-Bracero, O. L.; Zurcher, F.; Gioda, A.; Lee, T.; Collett, J. L.; Pradacs Team

    2010-12-01

    The underlying physico-chemical processes of dust-aerosol interactions are poorly understood; even less understood is how aging impacts cloud properties and climate as the particles travel from Africa to the Caribbean region. Caribbean landmasses have Tropical Montane Cloud Forests (TMCFs) that are tightly coupled to the atmospheric hydrologic cycle. Small-scale shifts in temperature and precipitation could have serious ecological consequences. Therefore, this makes TMCFs an interesting ecosystem to see the effects African Dust (AD) might have on cloud formation and precipitation. The first field measurements of the Puerto Rico African Dust and Clouds Study (PRADACS) were from July 22 to August 12, 2010. Measurements were performed at East Peak (EP) station at Luquillo, PR (1051 masl) and Cape San Juan Station (CSJ), a coastal station at Fajardo, PR (~60 masl). At EP, two cloud collectors (i.e., single stage (Aluminum version) and 2-stage (Teflon version) Caltech Active Strand Cloudwater Collector (CASCC)), and a rainwater collector were operated. Chemical composition (water-soluble ions and carbonaceous, organic nitrogen and metals) and pH were determined for the cloud water and rainwater samples. Here we present preliminary results for EP station. For cloud water and rainwater sampling, pH was 5.5 in average, but during dust events pH values were higher due to the presence of cations that form hydroxides in aqueous solution. Conductivity measurements ranged from 20 to 120 μs/cm; being higher on dust events and lower for rain samples. The values of pH and conductivity in the first stage (large droplets of approximately 15 μm are collected) indicate a higher content of dust than in the second stage (small droplets of approximately 5 μm). This is consistent with the larger sizes of dust particles as well as their lower hygroscopicity which requires more water to serve as Cloud Condensation Nuclei (CCN). Additional results for physical properties and chemical

  19. Household vacuum cleaners vs. the high-volume surface sampler for collection of carpet dust samples in epidemiologic studies of children

    PubMed Central

    Colt, Joanne S; Gunier, Robert B; Metayer, Catherine; Nishioka, Marcia G; Bell, Erin M; Reynolds, Peggy; Buffler, Patricia A; Ward, Mary H

    2008-01-01

    Background Levels of pesticides and other compounds in carpet dust can be useful indicators of exposure in epidemiologic studies, particularly for young children who are in frequent contact with carpets. The high-volume surface sampler (HVS3) is often used to collect dust samples in the room in which the child had spent the most time. This method can be expensive and cumbersome, and it has been suggested that an easier method would be to remove dust that had already been collected with the household vacuum cleaner. However, the household vacuum integrates exposures over multiple rooms, some of which are not relevant to the child's exposure, and differences in vacuuming equipment and practices could affect the chemical concentration data. Here, we compare levels of pesticides and other compounds in dust from household vacuums to that collected using the HVS3. Methods Both methods were used in 45 homes in California. HVS3 samples were collected in one room, while the household vacuum had typically been used throughout the home. The samples were analyzed for 64 organic compounds, including pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls (PCBs), using GC/MS in multiple ion monitoring mode; and for nine metals using conventional microwave-assisted acid digestion combined with ICP/MS. Results The methods agreed in detecting the presence of the compounds 77% to 100% of the time (median 95%). For compounds with less than 100% agreement, neither method was consistently more sensitive than the other. Median concentrations were similar for most analytes, and Spearman correlation coefficients were 0.60 or higher except for allethrin (0.15) and malathion (0.24), which were detected infrequently, and benzo(k)fluoranthene (0.55), benzo(a)pyrene (0.55), PCB 105 (0.54), PCB 118 (0.54), and PCB 138 (0.58). Assuming that the HVS3 method is the "gold standard," the extent to which the household vacuum cleaner method yields relative risk estimates closer to

  20. The complementarity of PIXE and PIGE techniques: A case study of size segregated airborne particulates collected from a Nigeria city.

    PubMed

    Ezeh, G C; Obioh, I B; Asubiojo, O I; Chiari, M; Nava, S; Calzolai, G; Lucarelli, F; Nuviadenu, C

    2015-09-01

    The Proton Induced X-ray Emission (PIXE) technique is a reliable ion beam analytical tool for the characterization of thin aerosol samples, but it can underestimate the lightest measurable elements (such as Na, Mg, Al and Si) owing to the absorption of their X-rays inside the sample. The Proton Induced Gamma-ray Emission (PIGE) technique could be employed as avalid means to determine corrections for such an effect. Hence, in this study, Fine (PM(2.5)) and Coarse (PM(10-2.5)) particulate matter samples collected at Ikeja, Lagos-Nigeria, using a double staged 'Gent' stacked sampler were analyzed for their elemental concentrations using an external beam set-up for simultaneous PIXE and PIGE measurements. The measured PIXE concentrations as well as the PIGE correction factors for Na and Al detected in the PM(10-2.5) samples (collected on polycarbonate Nuclepore membranes) are reported. The concentrations of 24 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Zr, Cs and Pb) detected in both fractions were displayed, discussed and likely sources of these elements were also identified.

  1. Improve dust capture on your surface drill

    SciTech Connect

    Page, S.J.; Listak, J.M.; Reed, R.

    2008-09-15

    Researchers have developed a model to describe airborne respirable dust (ARD) generation on surface coal mine drills. By measuring a few basic parameters and using a graph, a drill operator or engineer can estimate the relative severity of drill dust emissions as well as how much of a reduction in ARD can be obtained by changing any given parameter. 4 refs., 2 figs.

  2. Ice Nucleating Particle Properties in the Saharan Air Layer Close to the Dust Source

    NASA Astrophysics Data System (ADS)

    Boose, Y.; Garcia, I. M.; Rodríguez, S.; Linke, C.; Schnaiter, M.; Nickovic, S.; Lohmann, U.; Kanji, Z. A.; Sierau, B.

    2015-12-01

    In August 2013 and 2014 measurements of ice nucleating particle (INP) concentrations, aerosol particle size distributions, chemistry and fluorescence were conducted at the Izaña Atmospheric Observatory located at 2373 m asl on Tenerife, west off the African shore. During summer, the observatory is frequently within the Saharan Air Layer and thus often exposed to dust. Absolute INP concentrations and activated fractions at T=-40 to -15°C and RHi=100-150 % were measured. In this study, we discuss the in-situ measured INP properties with respect to changes in the chemical composition, the biological content, the source regions as well as transport pathways and thus aging processes of the dust aerosol. For the first time, ice crystal residues were also analyzed with regard to biological content by means of their autofluorescence signal close to a major dust source region. Airborne dust samples were collected with a cyclone for additional offline analysis in the laboratory under similar conditions as in the field. Both, in-situ and offline dust samples were chemically characterized using single-particle mass spectrometry. The DREAM8 dust model extended with dust mineral fractions was run to simulate meteorological and dust aerosol conditions for ice nucleation. Results show that the background aerosol at Izaña was dominated by carbonaceous particles, which were hardly ice-active under the investigated conditions. When Saharan dust was present, INP concentrations increased by up to two orders of magnitude even at water subsaturated conditions at T≤-25°C. Differences in the ice-activated fraction were found between different dust periods which seem to be linked to variations in the aerosol chemical composition (dust mixed with changing fractions of sea salt and differences in the dust aerosol itself). Furthermore, two biomass burning events in 2014 were identified which led to very low INP concentrations under the investigated temperature and relative humidity

  3. The physical nature of interplanetary dust as inferred by particles collected at 35 km. [morphology of micrometeorites and ablation products

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.; Hodge, P. W.; Bucher, W.

    1973-01-01

    Particles were collected at an altitude of 35 km by two flights of a volume sampling micrometeorite collector. The collection scheme is very sensitive and is capable of collecting a significant number of particles. Many of the particles collected have chemical compositions similar to solar or to iron meteorites. Morphology of collected particles indicates that both true micrometeorites and ablation products were collected.

  4. Analysis of dust samples from the Middle East using high-density resequencing micro-array RPM-TEI

    NASA Astrophysics Data System (ADS)

    Leski, T. A.; Gregory, M. J.; Malanoski, A. P.; Smith, J. P.; Glaven, R. H.; Wang, Z.; Stenger, D. A.; Lin, B.

    2010-04-01

    A previously developed resequencing microarray, "Tropical and Emerging Infections (RPM-TEI v.1.0 chip)", designed to identify and discriminate between tropical diseases and other potential biothreat agents, their near-neighbor species, and/or potential confounders, was used to characterize the microbes present in the silt/clay fraction of surface soils and airborne dust collected from the Middle East. Local populations and U.S. military personnel deployed to the Middle East are regularly subjected to high levels of airborne desert dust containing a significant fraction of inhalable particles and some portion require clinical aid. Not all of the clinical symptoms can be directly attributed to the physical action of material in the human respiratory tract. To better understand the potential health effects of the airborne dust, the composition of the microbial communities associated with surface soil and/or airborne dust (air filter) samples from 19 different sites in Iraq and Kuwait was identified using RPM-TEI v.1.0. Results indicated that several microorganisms including a class of rapidly growing Mycobacterium, Bacillus, Brucella, Clostridium and Coxiella burnetti, were present in the samples. The presence of these organisms in the surface soils and the inhalable fraction of airborne dust analyzed may pose a human health risk and warrants further investigation. Better understanding of the factors influencing the composition of these microbial communities is important to address questions related to human health and is critical to achieving Force Health Protection for the Warfighter operating in the Middle East, Afghanistan, North Africa and other arid regions.

  5. Natural-color and color-infrared image mosaics of the Colorado River corridor in Arizona derived from the May 2009 airborne image collection

    USGS Publications Warehouse

    Davis, Philip A.

    2013-01-01

    The Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey (USGS) periodically collects airborne image data for the Colorado River corridor within Arizona (fig. 1) to allow scientists to study the impacts of Glen Canyon Dam water release on the corridor’s natural and cultural resources. These data are collected from just above Glen Canyon Dam (in Lake Powell) down to the entrance of Lake Mead, for a total distance of 450 kilometers (km) and within a 500-meter (m) swath centered on the river’s mainstem and its seven main tributaries (fig. 1). The most recent airborne data collection in 2009 acquired image data in four wavelength bands (blue, green, red, and near infrared) at a spatial resolution of 20 centimeters (cm). The image collection used the latest model of the Leica ADS40 airborne digital sensor (the SH52), which uses a single optic for all four bands and collects and stores band radiance in 12-bits. Davis (2012) reported on the performance of the SH52 sensor and on the processing steps required to produce the nearly flawless four-band image mosaic (sectioned into map tiles) for the river corridor. The final image mosaic has a total of only 3 km of surface defects in addition to some areas of cloud shadow because of persistent inclement weather during data collection. The 2009 four-band image mosaic is perhaps the best image dataset that exists for the entire Arizona part of the Colorado River. Some analyses of these image mosaics do not require the full 12-bit dynamic range or all four bands of the calibrated image database, in which atmospheric scattering (or haze) had not been removed from the four bands. To provide scientists and the general public with image products that are more useful for visual interpretation, the 12-bit image data were converted to 8-bit natural-color and color-infrared images, which also removed atmospheric scattering within each wavelength-band image. The conversion required an evaluation of the

  6. Natural-color and color-infrared image mosaics of the Colorado River corridor in Arizona derived from the May 2009 airborne image collection

    USGS Publications Warehouse

    Davis, Philip A.

    2013-01-01

    The Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey (USGS) periodically collects airborne image data for the Colorado River corridor within Arizona (fig. 1) to allow scientists to study the impacts of Glen Canyon Dam water release on the corridor’s natural and cultural resources. These data are collected from just above Glen Canyon Dam (in Lake Powell) down to the entrance of Lake Mead, for a total distance of 450 kilometers (km) and within a 500-meter (m) swath centered on the river’s mainstem and its seven main tributaries (fig. 1). The most recent airborne data collection in 2009 acquired image data in four wavelength bands (blue, green, red, and near infrared) at a spatial resolution of 20 centimeters (cm). The image collection used the latest model of the Leica ADS40 airborne digital sensor (the SH52), which uses a single optic for all four bands and collects and stores band radiance in 12-bits. Davis (2012) reported on the performance of the SH52 sensor and on the processing steps required to produce the nearly flawless four-band image mosaic (sectioned into map tiles) for the river corridor. The final image mosaic has a total of only 3 km of surface defects in addition to some areas of cloud shadow because of persistent inclement weather during data collection. The 2009 four-band image mosaic is perhaps the best image dataset that exists for the entire Arizona part of the Colorado River. Some analyses of these image mosaics do not require the full 12-bit dynamic range or all four bands of the calibrated image database, in which atmospheric scattering (or haze) had not been removed from the four bands. To provide scientists and the general public with image products that are more useful for visual interpretation, the 12-bit image data were converted to 8-bit natural-color and color-infrared images, which also removed atmospheric scattering within each wavelength-band image. The conversion required an evaluation of the

  7. Reducing Coal Dust With Water Jets

    NASA Technical Reports Server (NTRS)

    Gangal, M. D.; Lewis, E. V.

    1985-01-01

    Jets also cool and clean cutting equipment. Modular pick-and-bucket miner suffers from disadvantage: Creates large quantities of potentially explosive coal dust. Dust clogs drive chain and other parts and must be removed by hand. Picks and bucket lips become overheated by friction and be resharpened or replaced frequently. Addition of oscillating and rotating water jets to pick-and-bucket machine keeps down dust, cools cutting edges, and flushes machine. Rotating jets wash dust away from drive chain. Oscillating jets cool cutting surfaces. Both types of jet wet airborne coal dust; it precipitates.

  8. Comparative Toxicity of Size-Fractionated Airborne Particulate Matter Collected at Different Distances from an Urban Highway

    PubMed Central

    Cho, Seung-Hyun; Tong, Haiyan; McGee, John K.; Baldauf, Richard W.; Krantz, Q. Todd; Gilmour, M. Ian

    2009-01-01

    Background Epidemiologic studies have reported an association between proximity to highway traffic and increased cardiopulmonary illnesses. Objectives We investigated the effect of size-fractionated particulate matter (PM), obtained at different distances from a highway, on acute cardiopulmonary toxicity in mice. Methods We collected PM for 2 weeks in July–August 2006 using a three-stage (ultrafine, < 0.1 μm; fine, 0.1–2.5 μm; coarse, 2.5–10 μm) high-volume impactor at distances of 20 m [near road (NR)] and 275 m [far road (FR)] from an interstate highway in Raleigh, North Carolina. Samples were extracted in methanol, dried, diluted in saline, and then analyzed for chemical constituents. Female CD-1 mice received either 25 or 100 μg of each size fraction via oropharyngeal aspiration. At 4 and 18 hr postexposure, mice were assessed for pulmonary responsiveness to inhaled methacholine, biomarkers of lung injury and inflammation; ex vivo cardiac pathophysiology was assessed at 18 hr only. Results Overall chemical composition between NR and FR PM was similar, although NR samples comprised larger amounts of PM, endotoxin, and certain metals than did the FR samples. Each PM size fraction showed differences in ratios of major chemical classes. Both NR and FR coarse PM produced significant pulmonary inflammation irrespective of distance, whereas both NR and FR ultrafine PM induced cardiac ischemia–reperfusion injury. Conclusions On a comparative mass basis, the coarse and ultrafine PM affected the lung and heart, respectively. We observed no significant differences in the overall toxicity end points and chemical makeup between the NR and FR PM. The results suggest that PM of different size-specific chemistry might be associated with different toxicologic mechanisms in cardiac and pulmonary tissues. PMID:20049117

  9. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

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

  10. Direct Characterization of Airborne Particles Associated with Arsenic-rich Mine Tailings: Particle Size Mineralogy and Texture

    SciTech Connect

    M Corriveau; H Jamieson; M Parsons; J Campbell; A Lanzirotti

    2011-12-31

    Windblown and vehicle-raised dust from unvegetated mine tailings can be a human health risk. Airborne particles from As-rich abandoned Au mine tailings from Nova Scotia, Canada have been characterized in terms of particle size, As concentration, As oxidation state, mineral species and texture. Samples were collected in seven aerodynamically fractionated size ranges (0.5-16 {micro}m) using a cascade impactor deployed at three tailings fields. All three sites are used for recreational activities and off-road vehicles were racing on the tailings at two mines during sample collection. Total concentrations of As in the <8 {micro}m fraction varied from 65 to 1040 ng/m{sup 3} of air as measured by proton-induced X-ray emission (PIXE) analysis. The same samples were analysed by synchrotron-based microfocused X-ray absorption near-edge spectroscopy ({micro}XANES) and X-ray diffraction ({micro}XRD) and found to contain multiple As-bearing mineral species, including Fe-As weathering products. The As species present in the dust were similar to those observed in the near-surface tailings. The action of vehicles on the tailings surface may disaggregate material cemented with Fe arsenate and contribute additional fine-grained As-rich particles to airborne dust. Results from this study can be used to help assess the potential human health risks associated with exposure to airborne particles from mine tailings.

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

    PubMed

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

    2004-03-01

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

  12. Saharan Dust over Senegal

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Airborne African dust regularly reaches northeastern South America and the Caribbean. Westward dust transport from the Sahara across the central Atlantic has been a common occurrence this spring, with major events visible in both satellite images and photographs. Cap Vert, the westernmost point of Senegal, is dimly visible beneath the dust mass (center); the Arquipelago dos Bijagos in Guinea Bissau lies opposite the mouth of the sediment-laden Rio Corubal. This photo (ISS004-E-12080) was taken by the crew of the International Space Station on May 18, 2002, using a digital camera with a 35-mm lens. Image provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  13. Living on the Lunar Surface: Determining the Health Effects of Exposure to Respirable Lunar Dusts

    NASA Astrophysics Data System (ADS)

    Khan-Mayberry, N. N.

    2008-07-01

    NASA formed the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to determine the toxicological effects of lunar dust. This interdisciplinary group is comprised of leading experts in space toxicology, lunar geology, space medicine and biomedical research.

  14. Size-resolved Chemical Composition of Cloud and Rain Water Collected during the Puerto Rico African Dust and Clouds Study (PRADACS) Campaign

    NASA Astrophysics Data System (ADS)

    Torres, E.; Valle Diaz, C. J.; Zurcher, F.; Lee, T.; Collett, J. L.; Fitzgerald, E.; Cuadra, L.; Prather, K. A.; Mayol-Bracero, O. L.

    2011-12-01

    The underlying physico-chemical processes of dust-aerosol interactions are poorly understood; even less understood is how aging impacts cloud properties and climate as the particles travel from Africa to the Caribbean region. Caribbean landmasses have tropical montane cloud forests (TMCFs) that are tightly coupled to the atmospheric hydrologic cycle. Small-scale shifts in temperature and precipitation could have serious ecological consequences. Therefore, this makes TMCFs an interesting ecosystem to see the effects African Dust (AD) might have on cloud formation and precipitation. As part of the Puerto Rico African Dust and Clouds Study (PRADACS) cloud and rain water samples for subsequent chemical analysis were collected at Pico del Este (PE) station in Luquillo, PR (1051 masl) during summer 2011. At PE, two cloud collectors (i.e., single stage (Aluminum version) and 2-stage (Teflon version) Caltech Active Strand Cloudwater Collector (CASCC)), and a rainwater collector were operated. Measurements such as the liquid water content (LWC), pH, conductivity., and composition of single particles using an aerosol time of flight mass spectrometer (ATOFMS) were performed. Preliminary results showed that days with the influence of African dust (AD), had LWC values that ranged from 300 to 500 mg/m3, pH values up to 5.7,, and conductivity up to 180 μS/cm. The ATOFMS showed titanium and iron ions, suggesting the presence of AD as well as, occasionally, sulfate and nitrate ions suggesting the influence of anthropogenic pollution. Results on the chemical composition and the physical properties of cloud, rainwater, and aerosol for the inorganic as well as the organic fraction and how these properties change for the different air masses observed will also be presented.

  15. Contributions of the secondary jet to the maximum tangential velocity and to the collection efficiency of the fixed guide vane type axial flow cyclone dust collector

    NASA Astrophysics Data System (ADS)

    Ogawa, Akira; Anzou, Hideki; Yamamoto, So; Shimagaki, Mituru

    2015-11-01

    In order to control the maximum tangential velocity Vθm(m/s) of the turbulent rotational air flow and the collection efficiency ηc (%) using the fly ash of the mean diameter XR50=5.57 µm, two secondary jet nozzles were installed to the body of the axial flow cyclone dust collector with the body diameter D1=99mm. Then in order to estimate Vθm (m/s), the conservation theory of the angular momentum flux with Ogawa combined vortex model was applied. The comparisons of the estimated results of Vθm(m/s) with the measured results by the cylindrical Pitot-tube were shown in good agreement. And also the estimated collection efficiencies ηcth (%) basing upon the cut-size Xc (µm) which was calculated by using the estimated Vθ m(m/s) and also the particle size distribution R(Xp) were shown a little higher values than the experimental results due to the re-entrainment of the collected dust. The best method for adjustment of ηc (%) related to the contribution of the secondary jet flow is principally to apply the centrifugal effect Φc (1). Above stated results are described in detail.

  16. Hebes Chasma Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located in Hebes Chasma.

    Image information: VIS instrument. Latitude -1.4, Longitude 286.6 East (73.4 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  17. Mineralogical analysis of attic dust samples for contamination source identification in an industrial area, Ajka, Hungary

    NASA Astrophysics Data System (ADS)

    Völgyesi, Péter; Jordan, Gyozo; Gosar, Mateja; Szabó, Csaba; Miler, Miloš; Kónya, Péter; Bartha, András

    2013-04-01

    The post-war centrally directed economy forced massive heavy industry in Hungary, producing huge amount of wastes and pollution. Long-term airborne emissions from mining, coal-fired power plants and alumina industry have left the legacy of widely distributed contamination around industrial areas and nearby settlements in the Ajka region. Recent research suggests that significant amount of airborne pollutants, deposited in the urban environment, can be efficiently studied by attic dust analysis. The sampling strategy followed a grid-based stratified random sampling design and 30 samples were collected in 27 houses (at least 30 years old) in a 8x8 grid of the 64 km2 project area. In order to determine the pollution potential of attic dust samples, geochemical and mineralogical analyses were performed. The main aim of the mineralogical analyses was to study the phase composition of the dust particles and to identify potential anthropogenic sources. The total concentrations of the toxic elements (As, Pb, Cd, Cu, Ni and Zn) were measured with ICP-OES and mercury content was analyzed with atomic absorption spectrometry. Phase analyses of the samples were carried out by the means of scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and X-Ray diffraction (XRD) methods. Laser particle size analyzer was used to measure the grain size of attic dust particles. Results showed that the studied attic dust in the Ajka urban area was contaminated mostly by Hg, Pb and Zn with contents ranging between 0.1-2 ppm, 42.5-881 ppm and 90.2-954 ppm, respectively. However, the study of extreme data values (statistical outliers) has shown that at certain points airborne dust can be extremely contaminated also with Cd (0.4-11.7 ppm). The size of the attic dust particles varied between 0.2 and 113 µm. Based on the SEM/EDS and XRD analysis, the most frequently identified mineralogical phases were quartz, calcite, gypsum and Fe- and Al-bearing phases. Fe

  18. Molecular detection of airborne Coccidioides in Tucson, Arizona

    USGS Publications Warehouse

    Chow, Nancy A.; Griffin, Dale W.; Barker, Bridget M.; Loparev, Vladimir N.; Litvintseva, Anastasia P.

    2016-01-01

    Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detectingCoccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides.

  19. Molecular detection of airborne Coccidioides in Tucson, Arizona.

    PubMed

    Chow, Nancy A; Griffin, Dale W; Barker, Bridget M; Loparev, Vladimir N; Litvintseva, Anastasia P

    2016-08-01

    Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detecting Coccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides. PMID:27143633

  20. Dust storm off Western Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The impacts of Saharan dust storms reach far beyond Africa. Wind-swept deserts spill airborne dust particles out over the Atlantic Ocean where they can enter trade winds bound for Central and North America and the Caribbean. This Moderate Resolution Imaging Spectroradiometer (MODIS) image shows a dust storm casting an opaque cloud of cloud across the Canary Islands and the Atlantic Ocean west of Africa on June 30, 2002. In general it takes between 5 and 7 days for such an event to cross the Atlantic. The dust has been shown to introduce foreign bacteria and fungi that have damaged reef ecosystems and have even been hypothesized as a cause of increasing occurrences of respiratory complaints in places like Florida, where the amount of Saharan dust reaching the state has been increasing over the past 25 years.

  1. Imaging-based dust sensors: equipment and methods

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Greco, Sonia

    2004-05-01

    Dust detection and control in real time, represent one of the most challenging problem in all those environments where fine and ultrafine airborne particulate solids products are present. The presence of such products can be linked to several factors, often directly related and influenced by the working-production actions performed. Independently from the causes generating dust, airborne contaminants are an occupational problem of increasing interest as they are related to a wide number of diseases. In particular, airborne dusts are well known to be associated with several classical occupational lung diseases, such as the pneumoconiosis, especially at high levels of exposure. Nowadays there is also an increasing interest in other dust related diseases, from the most serious as cancer and asthma, to those related with allergies or irritation and other illnesses, also occurring at lower levels of exposure. Among the different critical factors influencing health risk for airborne dust exposure, mainly four have to be considered, that is: i) nature of the dust resulting from working in terms of presence of specific poisoning material, i.e. free silica, and morphological and morphometrical attributes of particulates constituting airborne dust; ii) size of the particles, iii) duration of exposure time and, finally, iv) airborne dust concentration in the breathing zone where the worker performs his activity. A correct dust detection is not easy, especially if some of the previous mentioned factors, have to be detected and quantified in real time in order to define specific "on-line" control actions aimed to reduce the level of the exposure to dust of the workers, as for example: i) modification of aspirating devices operating condition, change of filtering cleaning sequence, etc. . The more severe are the environmental conditions, in terms of dust presence (in quantity and quality) more difficult is to utilize efficient sampling devices. Detection devices, in fact, tend

  2. Long-range-transported Saharan dust in the Caribbean - an electron microscopy perspective of aerosol composition and modification

    NASA Astrophysics Data System (ADS)

    Kandler, Konrad; Hartmann, Markus; Ebert, Martin; Weinbruch, Stephan; Weinzierl, Bernadett; Walser, Adrian; Sauer, Daniel; Wadinga Fomba, Khanneh

    2015-04-01

    From June to July in 2013, the Saharan Aerosol Long-range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE) was performed in the Caribbean. Airborne aerosol sampling was performed onboard the DLR Falcon aircraft in altitudes between 300 m and 5500 m. Ground-based samples were collected at Ragged Point (Barbados, 13.165 °N, 59.432 °W) and at the Cape Verde Atmospheric Observatory (Sao Vicente, 16.864 °N, 24.868 °W). Different types of impactors and sedimentation samplers were used to collect particles between 0.1 µm and 4 µm (airborne) and between 0.1 µm and 100 µm (ground-based). Particles were analyzed by scanning electron microscopy with attached energy-dispersive X-ray analysis, yielding information on particle size, particle shape and chemical composition for elements heavier than nitrogen. A particle size correction was applied to the chemical data to yield better quantification. A total of approximately 100,000 particles were analyzed. For particles larger than 0.7 µm, the aerosol in the Caribbean during the campaign was a mixture of mineral dust, sea-salt at different aging states, and sulfate. Inside the Saharan dust plume - outside the marine boundary layer (MBL) - the aerosol is absolutely dominated by mineral dust. Inside the upper MBL, sea-salt exists as minor component in the aerosol for particles smaller than 2 µm in diameter, larger ones are practically dust only. When crossing the Soufriere Hills volcano plume with the aircraft, an extremely high abundance of small sulfate particles could be observed. At Ragged Point, in contrast to the airborne measurements, aerosol is frequently dominated by sea-salt particles. Dust relative abundance at Ragged Point has a maximum between 5 µm and 10 µm particles diameter; at larger sizes, sea-salt again prevails due to the sea-spray influence. A significant number of dust particles larger than 20 µm was encountered. The dust component in the Caribbean - airborne as well as ground

  3. Proof-of-principle results for identifying the composition of dust particles and volcanic ash samples through the technique of photon activation analysis at the IAC

    NASA Astrophysics Data System (ADS)

    Mamtimin, Mayir; Cole, Philip L.; Segebade, Christian

    2013-04-01

    Instrumental analytical methods are preferable in studying sub-milligram quantities of airborne particulates collected in dust filters. The multi-step analytical procedure used in treating samples through chemical separation can be quite complicated. Further, due to the minute masses of the airborne particulates collected on filters, such chemical treatment can easily lead to significant levels of contamination. Radio-analytical techniques, and in particular, activation analysis methods offer a far cleaner alternative. Activation methods require minimal sample preparation and provide sufficient sensitivity for detecting the vast majority of the elements throughout the periodic table. In this paper, we will give a general overview of the technique of photon activation analysis. We will show that by activating dust particles with 10- to 30-MeV bremsstrahlung photons, we can ascertain their elemental composition. The samples are embedded in dust-collection filters and are irradiated "as is" by these photons. The radioactivity of the photonuclear reaction products is measured with appropriate spectrometers and the respective analytes are quantified using multi-component calibration materials. We shall provide specific examples of identifying the elemental components of airborne dust particles and volcanic ash by making use of bremsstrahlung photons from an electron linear accelerator at the Idaho Accelerator Center in Pocatello, Idaho.

  4. Dust Growth by RF Sputtering

    SciTech Connect

    Churton, B.; Samarian, A. A.; Coueedel, L.

    2008-09-07

    The effect of the dust particle growth by RF sputtering on glow discharge has been investigated. It has been found that the growth of dust particles modifies the electrical characteristics of the discharge. In particularly, the absolute value of the self-bias voltage decreases during the particle growth due to the electron losses on the dust particles. To find the correlation between the dust growth and the self bias evolution, dust particles have been collected at different times. The dust particle growth rate is found to be linear.

  5. Direct analysis of airborne mite allergen (Der f1) in the residential atmosphere by chemifluorescent immunoassay using bioaerosol sampler.

    PubMed

    Miyajima, Kumiko; Suzuki, Yurika; Miki, Daisuke; Arai, Moeka; Arakawa, Takahiro; Shimomura, Hiroji; Shiba, Kiyoko; Mitsubayashi, Kohji

    2014-06-01

    Dermatophagoides farinae allergen (Der f1) is one of the most important indoor allergens associated with allergic diseases in humans. Mite allergen Der f1 is usually associated with particles of high molecular weight; thus, Der f1 is generally present in settled dust. However, a small quantity of Der f1 can be aerosolized and become an airborne component. Until now, a reliable method of detecting airborne Der f1 has not been developed. The aim of this study was to develop a fiber-optic chemifluorescent immunoassay for the detection of airborne Der f1. In this method, the Der f1 concentration measured on the basis of the intensity of fluorescence amplified by an enzymatic reaction between the labeled enzyme by a detection antibody and a fluorescent substrate. The measured Der f1 concentration was in the range from 0.49 to 250 ng/ml and a similar range was found by enzyme-linked immunosorbent assay (ELISA). This method was proved to be highly sensitive to Der f1 compared with other airborne allergens. For the implementation of airborne allergen measurement in a residential environment, a bioaerosol sampler was constructed. The airborne allergen generated by a nebulizer was conveyed to a newly sampler we developed for collecting airborne Der f1. The sampler was composed of polymethyl methacrylate (PMMA) cells for gas/liquid phases and some porous membranes which were sandwiched in between the two phases. Der f1 in air was collected by the sampler and measured using the fiber-optic immunoassay system. The concentration of Der f1 in aerosolized standards was in the range from 0.125 to 2.0 mg/m(3) and the collection rate of the device was approximately 0.2%.

  6. Ochratoxin A in grain dust--estimated exposure and relations to agricultural practices in grain production.

    PubMed

    Halstensen, Anne Straumfors; Nordby, Karl-Christian; Elen, Oleif; Eduard, Wijnand

    2004-01-01

    Ochratoxin A (OTA) is a nephrotoxin frequently contaminating grains. OTA inhalation during grain handling may therefore represent a health risk to farmers, and was the subject of this study. Airborne and settled grain dust was collected during grain work on 84 Norwegian farms. Climate and agricultural practices on each farm were registered. Penicillium spp., Aspergillus spp. and OTA in settled dust were measured. Settled dust contained median 4 microg OTA/kg dust (range 2-128), correlating with Penicillium spp. (median 40 cfu/mg; range 0-32000, rs =0.33; p < 0.01). Similar levels were found across grain species, districts and agricultural practices. Penicillium levels, but not OTA levels, were higher in storage than in threshing dust (p=0.003), and increased with storage time (rs =0.51, p < 0.001). Farmers were exposed to median 1 mg/m3 (range 0.2-15) dust during threshing and median 7 mg/m3 (range 1-110) dust during storage work, equalling median 3.7 pg/m3 (range 0.6-200) and median 40 pg/m3 (range 2-14000) OTA, respectively (p < 0.001). Agricultural practices could not predict OTA, Penicillium or Aspergillus contamination. Compared to oral intake of OTA, the inhalant exposure during grain work was low, although varying by more than 1,000-fold. However, the farmers may occasionally be highly exposed, particularly during handling of stored grain.

  7. Aeolian dust emissions in Southern Africa: field measurements of dynamics and drivers

    NASA Astrophysics Data System (ADS)

    Wiggs, Giles; Thomas, David; Washington, Richard; King, James; Eckardt, Frank; Bryant, Robert; Nield, Joanna; Dansie, Andrew; Baddock, Matthew; Haustein, Karsten; Engelstaedter, Sebastian; von Holdt, Johannah; Hipondoka, Martin; Seely, Mary

    2016-04-01

    Airborne dust derived from the world's deserts is a critical component of Earth System behaviour, affecting atmospheric, oceanic, biological, and terrestrial processes as well as human health and activities. However, very few data have been collected on the factors that control dust emission from major source areas, or on the characteristics of the dust that is emitted. Such a paucity of data limits the ability of climate models to properly account for the radiative and dynamical impacts triggered by atmospheric dust. This paper presents field data from the DO4 Models (Dust Observations for Models) project that aims to understand the drivers of variability in dust emission processes from major source areas in southern Africa. Data are presented from three field campaigns undertaken between 2011 and 2015. We analysed remote sensing data to identify the key geomorphological units in southern Africa which are responsible for emission of atmospheric dust. These are the Makgadikgadi pans complex in northern Botswana, the ephemeral river valleys of western Namibia, and Etosha Pan in northern Namibia. Etosha Pan is widely recognised as perhaps the most significant source of atmospheric dust in the southern hemisphere. We deployed an array of field equipment within each source region to measure the variability in and dynamics of aeolian erosivity, as well as dust concentration and flux characteristics. This equipment included up to 11 meteorological stations measuring wind shear stress and other standard climatic parameters, Cimel sun photometers, a LiDAR, sediment transport detectors, high-frequency dust concentration monitors, and dust flux samplers. Further data were gathered at each site on the dynamics of surface characteristics and erodibility parameters that impact upon erosion thresholds. These data were augmented by use of a Pi-Swerl portable wind tunnel. Our data represent the first collected at source for these key dust emission areas and highlight the

  8. Occupational Exposure to Crystalline Silica Dust in the United States, 1988–2003

    PubMed Central

    Yassin, Abdiaziz; Yebesi, Francis; Tingle, Rex

    2005-01-01

    The purposes of this study were a) to summarize measurements of airborne (respirable) crystalline silica dust exposure levels among U.S. workers, b) to provide an update of the 1990 Stewart and Rice report on airborne silica exposure levels in high-risk industries and occupations with data for the time period 1988–2003, c) to estimate the number of workers potentially exposed to silica in industries that the Occupational Safety and Health Administration (OSHA) inspected for high exposure levels, and d) to conduct time trend analyses on airborne silica dust exposure levels for time-weighted average (TWA) measurements. Compliance inspection data that were taken from the OSHA Integrated Management Information System (IMIS) for 1988–2003 (n = 7,209) were used to measure the airborne crystalline silica dust exposure levels among U.S. workers. A second-order autoregressive model was applied to assess the change in the mean silica exposure measurements over time. The overall geometric mean of silica exposure levels for 8-hr personal TWA samples collected during programmed inspections was 0.077 mg/m3, well above the applicable American Conference of Governmental Industrial Hygienists threshold limit value of 0.05 mg/m3. Surgical appliances supplies industry [Standard Industrial Classification (SIC) 3842] had the lowest geometric mean silica exposure level of 0.017 mg/m3, compared with the highest level, 0.166 mg/m3, for the metal valves and pipe fitting industry (SIC 3494), for an 8-hr TWA measurement. Although a downward trend in the airborne silica exposure levels was observed during 1988–2003, the results showed that 3.6% of the sampled workers were exposed above the OSHA-calculated permissible exposure limit. PMID:15743711

  9. Dust exposure in Finnish foundries.

    PubMed

    Siltanen, E; Koponen, M; Kokko, A; Engström, B; Reponen, J

    1976-01-01

    Dust measurements were made in 51 iron, 9 steel, and 8 nonferrous foundries, at which 4,316 foundrymen were working. The sampling lasted at least two entire shifts or work days continuously during various operations in each foundry. The dust samples were collected at fixed sites or in the breathing zones of the workers. The mass concentration was determined by weighing and the respirable dust fraction was separated by liquid sedimentation. The free silica content was determined by X-ray diffraction. In the study a total of 3,188 samples were collected in the foundries and 6,505 determinations were made in the laboratory. The results indicated a definite difference in the dust exposure during various operations. The highest dust exposures were found during furnace, cupola, and pouring ladle repair. During cleaning work, sand mixing, and shake-out operations excessive silica dust concentrations were also measured. The lowest dust concentrations were measured during melting and pouring operations. Moderate dust concentrations were measured during coremaking and molding operations. The results obtained during the same operations of iron and steel foundries were similar. The distribution of the workers into various exposure categories, the content of respirable dust and quartz, the correlation between respirable dust and total dust, and the correlation between respirable silica and total dust concentrations are discussed. Observations concerning dust suppression and control methods are briefly considered.

  10. Boar spermatozoa as a biosensor for detecting toxic substances in indoor dust and aerosols.

    PubMed

    Andersson, M A; Mikkola, R; Rasimus, S; Hoornstra, D; Salin, P; Rahkila, R; Heikkinen, M; Mattila, S; Peltola, J; Kalso, S; Salkinoja-Salonen, M

    2010-10-01

    The presence, quantity and origins of potentially toxic airborne substances were searched in moisture damaged indoor environments, where building related ill health symptoms were suspected and reference sites with no health complaints. Boar spermatozoa were used as the toxicity sensor. Indoor aerosols and dusts were collected from kindergartens, schools, offices and residences (n=25) by electrostatic filtering, vacuuming, wiping from elevated surfaces and from the interior of personal computers. Toxicity was measured from the ethanol or methanol extracts of the dusts and aerosols. EC(50) was expressed as the lowest concentration of the airborne substance that inhibited motility of >50% of the exposed sperm cells compared to vehicle control, within 30 min, 1 day or 3-4 days of exposure. Remarkably toxic aerosols (EC(50) dusts. From these cereulide, amylosin, valinomycin and a novel indoor toxin, stephacidin B were identified and toxicities measured. Airborn dispersal of valinomycin from Streptomyces griseus cultures was evaluated using a flow-through chamber. Significant amounts of valinomycin (LC-MS assay) and toxicity (boar sperm motility assay) were carried by air and were after 14 days mainly recovered from the interior surfaces of the flow chamber.

  11. Manganese concentrations in soil and settled dust in an area with historic ferroalloy production.

    PubMed

    Pavilonis, Brian T; Lioy, Paul J; Guazzetti, Stefano; Bostick, Benjamin C; Donna, Filippo; Peli, Marco; Zimmerman, Neil J; Bertrand, Patrick; Lucas, Erika; Smith, Donald R; Georgopoulos, Panos G; Mi, Zhongyuan; Royce, Steven G; Lucchini, Roberto G

    2015-01-01

    Ferroalloy production can release a number of metals into the environment, of which manganese (Mn) is of major concern. Other elements include lead, iron, zinc, copper, chromium, and cadmium. Mn exposure derived from settled dust and suspended aerosols can cause a variety of adverse neurological effects to chronically exposed individuals. To better estimate the current levels of exposure, this study quantified the metal levels in dust collected inside homes (n=85), outside homes (n=81), in attics (n=6), and in surface soil (n=252) in an area with historic ferroalloy production. Metals contained in indoor and outdoor dust samples were quantified using inductively coupled plasma optical emission spectroscopy, whereas attic and soil measurements were made with a X-ray fluorescence instrument. Mean Mn concentrations in soil (4600 μg/g) and indoor dust (870 μg/g) collected within 0.5 km of a plant exceeded levels previously found in suburban and urban areas, but did decrease outside 1.0 km to the upper end of background concentrations. Mn concentrations in attic dust were ~120 times larger than other indoor dust levels, consistent with historical emissions that yielded high airborne concentrations in the region. Considering the potential health effects that are associated with chronic Mn inhalation and ingestion exposure, remediation of soil near the plants and frequent, on-going hygiene indoors may decrease residential exposure and the likelihood of adverse health effects. PMID:25335867

  12. Manganese concentrations in soil and settled dust in an area with historic ferroalloy production.

    PubMed

    Pavilonis, Brian T; Lioy, Paul J; Guazzetti, Stefano; Bostick, Benjamin C; Donna, Filippo; Peli, Marco; Zimmerman, Neil J; Bertrand, Patrick; Lucas, Erika; Smith, Donald R; Georgopoulos, Panos G; Mi, Zhongyuan; Royce, Steven G; Lucchini, Roberto G

    2015-01-01

    Ferroalloy production can release a number of metals into the environment, of which manganese (Mn) is of major concern. Other elements include lead, iron, zinc, copper, chromium, and cadmium. Mn exposure derived from settled dust and suspended aerosols can cause a variety of adverse neurological effects to chronically exposed individuals. To better estimate the current levels of exposure, this study quantified the metal levels in dust collected inside homes (n=85), outside homes (n=81), in attics (n=6), and in surface soil (n=252) in an area with historic ferroalloy production. Metals contained in indoor and outdoor dust samples were quantified using inductively coupled plasma optical emission spectroscopy, whereas attic and soil measurements were made with a X-ray fluorescence instrument. Mean Mn concentrations in soil (4600 μg/g) and indoor dust (870 μg/g) collected within 0.5 km of a plant exceeded levels previously found in suburban and urban areas, but did decrease outside 1.0 km to the upper end of background concentrations. Mn concentrations in attic dust were ~120 times larger than other indoor dust levels, consistent with historical emissions that yielded high airborne concentrations in the region. Considering the potential health effects that are associated with chronic Mn inhalation and ingestion exposure, remediation of soil near the plants and frequent, on-going hygiene indoors may decrease residential exposure and the likelihood of adverse health effects.

  13. Airborne exposures and risk of gastric cancer: a prospective cohort study.

    PubMed

    Sjödahl, Krister; Jansson, Catarina; Bergdahl, Ingvar A; Adami, Johanna; Boffetta, Paolo; Lagergren, Jesper

    2007-05-01

    There is an unexplained male predominance among patients with gastric cancer, and many carcinogens are found in male-dominated dusty occupations. However, the relation between occupational exposures and risk of gastric cancer remains unclear. To investigate whether airborne occupational exposures might influence the risk of noncardia gastric cancer, we used a large, prospective cohort study of male Swedish construction workers. These workers were, during the period 1971-1993, regularly invited to health examinations by a nationwide occupational health service organization. Data on job titles and other variables were collected through self-administered questionnaires and forms completed by the health organization's staff. Industrial hygienists assessed 12 specific airborne occupational exposures for 200 job titles. Gastric cancer, death or emigration occurring during follow-up in 1971-2002 were identified by linkage to the Swedish registers of Cancer, Causes of Death and Total Population, respectively. Incidence rate ratios (IRR) and 95% confidence intervals (CI), adjusted for attained age, tobacco smoking, calendar period and body mass, were derived from Cox regression. Among 256,357 cohort members, contributing 5,378,012 person-years at risk, 948 noncardia gastric cancers were identified. Increased risk of this tumor was found among workers exposed to cement dust (IRR 1.5 [95% CI 1.1-2.1]), quartz dust (IRR 1.3 [95% CI 1.0-1.7]) and diesel exhaust (IRR 1.4 [95% CI 1.1-1.9]). Dose-response relations were observed for these exposures. No consistent positive associations were found regarding exposure to asbestos, asphalt fumes, concrete dust, epoxy resins, isocyanates, metal fumes, mineral fibers, organic solvents or wood dust. In conclusion, this study provides some support to the hypothesis that specific airborne exposures increase the risk of noncardia gastric cancer. PMID:17266028

  14. Airborne exposures and risk of gastric cancer: a prospective cohort study.

    PubMed

    Sjödahl, Krister; Jansson, Catarina; Bergdahl, Ingvar A; Adami, Johanna; Boffetta, Paolo; Lagergren, Jesper

    2007-05-01

    There is an unexplained male predominance among patients with gastric cancer, and many carcinogens are found in male-dominated dusty occupations. However, the relation between occupational exposures and risk of gastric cancer remains unclear. To investigate whether airborne occupational exposures might influence the risk of noncardia gastric cancer, we used a large, prospective cohort study of male Swedish construction workers. These workers were, during the period 1971-1993, regularly invited to health examinations by a nationwide occupational health service organization. Data on job titles and other variables were collected through self-administered questionnaires and forms completed by the health organization's staff. Industrial hygienists assessed 12 specific airborne occupational exposures for 200 job titles. Gastric cancer, death or emigration occurring during follow-up in 1971-2002 were identified by linkage to the Swedish registers of Cancer, Causes of Death and Total Population, respectively. Incidence rate ratios (IRR) and 95% confidence intervals (CI), adjusted for attained age, tobacco smoking, calendar period and body mass, were derived from Cox regression. Among 256,357 cohort members, contributing 5,378,012 person-years at risk, 948 noncardia gastric cancers were identified. Increased risk of this tumor was found among workers exposed to cement dust (IRR 1.5 [95% CI 1.1-2.1]), quartz dust (IRR 1.3 [95% CI 1.0-1.7]) and diesel exhaust (IRR 1.4 [95% CI 1.1-1.9]). Dose-response relations were observed for these exposures. No consistent positive associations were found regarding exposure to asbestos, asphalt fumes, concrete dust, epoxy resins, isocyanates, metal fumes, mineral fibers, organic solvents or wood dust. In conclusion, this study provides some support to the hypothesis that specific airborne exposures increase the risk of noncardia gastric cancer.

  15. Continuous-flow leaching in a rotating coiled column for studies on the mobility of toxic elements in dust samples collected near a metallurgic plant.

    PubMed

    Fedotov, Petr S; Ermolin, Mikhail S; Ivaneev, Alexandr I; Fedyunina, Natalia N; Karandashev, Vasily K; Tatsy, Yury G

    2016-03-01

    Continuous-flow (dynamic) leaching in a rotating coiled column has been applied to studies on the mobility of Zn, Cd, Cu, Pb, Ni, Sb, As, S, and other potentially toxic elements in atmospherically deposited dust samples collected near a large copper smelter (Chelyabinsk region, Russia). Water and simulated "acid rain" (pH 4) were used as eluents. The technique enables not only the fast and efficient leaching of elements but as well time-resolved studies on the mobilization of heavy metals, sulphur, and arsenic in environmentally relevant forms to be made. It is shown that up to 1.5, 4.1, 1.9, 11.1, and 46.1% of Pb, As, Cu, Zn, and S, correspondingly, can be easily mobilized by water. Taking into consideration that the total concentrations of these elements in the samples under investigation are surprisingly high and vary in the range from 2.7 g/kg (for arsenic) to 15.5 g/kg (for sulphur), the environmental impact of the dust may be dramatic. The simulated acid rain results in somewhat higher recoveries of elements, except Cu and Pb. The proposed approach and the data obtained can very useful for the risk assessment related to the mobility of potentially toxic elements and their inclusion in the biogeochemical cycle.

  16. Continuous-flow leaching in a rotating coiled column for studies on the mobility of toxic elements in dust samples collected near a metallurgic plant.

    PubMed

    Fedotov, Petr S; Ermolin, Mikhail S; Ivaneev, Alexandr I; Fedyunina, Natalia N; Karandashev, Vasily K; Tatsy, Yury G

    2016-03-01

    Continuous-flow (dynamic) leaching in a rotating coiled column has been applied to studies on the mobility of Zn, Cd, Cu, Pb, Ni, Sb, As, S, and other potentially toxic elements in atmospherically deposited dust samples collected near a large copper smelter (Chelyabinsk region, Russia). Water and simulated "acid rain" (pH 4) were used as eluents. The technique enables not only the fast and efficient leaching of elements but as well time-resolved studies on the mobilization of heavy metals, sulphur, and arsenic in environmentally relevant forms to be made. It is shown that up to 1.5, 4.1, 1.9, 11.1, and 46.1% of Pb, As, Cu, Zn, and S, correspondingly, can be easily mobilized by water. Taking into consideration that the total concentrations of these elements in the samples under investigation are surprisingly high and vary in the range from 2.7 g/kg (for arsenic) to 15.5 g/kg (for sulphur), the environmental impact of the dust may be dramatic. The simulated acid rain results in somewhat higher recoveries of elements, except Cu and Pb. The proposed approach and the data obtained can very useful for the risk assessment related to the mobility of potentially toxic elements and their inclusion in the biogeochemical cycle. PMID:26741541

  17. Desert Dust Properties, Modelling, and Monitoring

    NASA Technical Reports Server (NTRS)

    Kaskaoutis, Dimitris G.; Kahn, Ralph A.; Gupta, Pawan; Jayaraman, Achuthan; Bartzokas, Aristides

    2013-01-01

    This paper is just the three-page introduction to a Special Issue of Advances in Meteorology focusing on desert dust. It provides a paragraph each on 13 accepted papers, most relating to the used of satellite data to assess attributes or distribution of airborne desert dust. As guest Associate Editors of this issue, we organized the papers into a systematic whole, beginning with large-scale transport and seasonal behavior, then to regional dust transport, transport history, and climate impacts, first in the Mediterranean region, then India and central Asia, and finally focusing on transport model assessment and the use of lidar as a technique to constrain dust spatial-temporal distribution.

  18. Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms

    PubMed Central

    Watanabe, Masanari; Kurai, Jun; Sano, Hiroyuki; Yamasaki, Akira; Shimizu, Eiji

    2015-01-01

    The associations between particulate matter from Asian dust storms (ADS) and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS). THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs), and tumor necrosis factor (TNF)-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control). Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS) and two (one ADS and one non-ADS) collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles. PMID:26184251

  19. Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms.

    PubMed

    Watanabe, Masanari; Kurai, Jun; Sano, Hiroyuki; Yamasaki, Akira; Shimizu, Eiji

    2015-07-01

    The associations between particulate matter from Asian dust storms (ADS) and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS). THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs), and tumor necrosis factor (TNF)-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control). Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS) and two (one ADS and one non-ADS) collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles. PMID:26184251

  20. Mutagenicity of airborne particles.

    PubMed

    Chrisp, C E; Fisher, G L

    1980-09-01

    The physical and chemical properties of airborne particles are important for the interpretation of their potential biologic significance as genotoxic hazards. For polydisperse particle size distributions, the smallest, most respirable particles are generally the most mutagenic. Particulate collection for testing purposes should be designed to reduce artifact formation and allow condensation of mutagenic compounds. Other critical factors such as UV irradiation, wind direction, chemical reactivity, humidity, sample storage, and temperature of combustion are important. Application of chemical extraction methods and subsequent class fractionation techniques influence the observed mutagenic activity. Particles from urban air, coal fly ash, automobile and diesel exhaust, agricultural burning and welding fumes contain primarily direct-acting mutagens. Cigarette smoke condensate, smoke from charred meat and protein pyrolysates, kerosene soot and cigarette smoke condensates contain primarily mutagens which require metabolic activation. Fractionation coupled with mutagenicity testing indicates that the most potent mutagens are found in the acidic fractions of urban air, coal fly ash, and automobile diesel exhaust, whereas mutagens in rice straw smoke and cigarette smoke condensate are found primarily in the basic fractions. The interaction of the many chemical compounds in complex mixtures from airborne particles is likely to be important in determining mutagenic or comutagenic potentials. Because the mode of exposure is generally frequent and prolonged, the presence of tumor-promoting agents in complex mixtures may be a major factor in evaluation of the carcinogenic potential of airborne particles.

  1. The Continuous Monitoring of Desert Dust using an Infrared-based Dust Detection and Retrieval Method

    NASA Technical Reports Server (NTRS)

    Duda, David P.; Minnis, Patrick; Trepte, Qing; Sun-Mack, Sunny

    2006-01-01

    Airborne dust and sand are significant aerosol sources that can impact the atmospheric and surface radiation budgets. Because airborne dust affects visibility and air quality, it is desirable to monitor the location and concentrations of this aerosol for transportation and public health. Although aerosol retrievals have been derived for many years using visible and near-infrared reflectance measurements from satellites, the detection and quantification of dust from these channels is problematic over bright surfaces, or when dust concentrations are large. In addition, aerosol retrievals from polar orbiting satellites lack the ability to monitor the progression and sources of dust storms. As a complement to current aerosol dust retrieval algorithms, multi-spectral thermal infrared (8-12 micron) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Meteosat-8 Spinning Enhanced Visible and Infrared Imager (SEVIRI) are used in the development of a prototype dust detection method and dust property retrieval that can monitor the progress of Saharan dust fields continuously, both night and day. The dust detection method is incorporated into the processing of CERES (Clouds and the Earth s Radiant Energy System) aerosol retrievals to produce dust property retrievals. Both MODIS (from Terra and Aqua) and SEVERI data are used to develop the method.

  2. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  3. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  4. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  5. 30 CFR 33.4 - Types of dust collectors for which certificates of approval may be granted.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.4 Types of dust collectors for which... specifically to prevent dissemination of airborne dust generated by drilling into coal-mine rock strata...

  6. Estimation of the collection efficiency of the axial flow cyclone dust collector with the fixed guide vanes

    NASA Astrophysics Data System (ADS)

    Ogawa, Akira; Iwanami, Tetzuya; Shono, Hideki

    1997-03-01

    In order to estimate the cut-size Xc and the mechanically balanced particles in the axial flow cyclone with the slit-separation method, the tangential velocity distributions were calculated by the finite difference method. In comparison of the calculated results of the total collection efficiency with the experimental results, the calculated results showed a little higher than the experimental results due to the re-entrainment of the collected particles by turbulence. The effect of the slit for promoting the collection efficiency was not recognized.

  7. Atmospheric aging of dust ice nucleating particles - a combined laboratory and field approach

    NASA Astrophysics Data System (ADS)

    Boose, Yvonne; Rodríguez, Sergio; García, M. Isabel; Linke, Claudia; Schnaiter, Martin; Zipori, Assaf; Crawford, Ian; Lohmann, Ulrike; Kanji, Zamin A.; Sierau, Berko

    2016-04-01

    We present INP data measured in-situ at two mostly free tropospheric locations: the High Altitude Research Station Jungfraujoch (JFJ) in the Swiss Alps, located at 3580 m above sea level (asl) and the Izaña observatory on Tenerife, off the West African shore (2373 m asl). INP concentrations were measured online with the Portable Ice Nucleation Chamber, PINC, at the Jungfraujoch in the winters of 2012, 2013 and 2014 and at Izaña in the summers of 2013 and 2014. Each measurement period lasted between 2 to 6 weeks. During summer, Izaña is frequently within the Saharan Air Layer and thus often exposed to Saharan dust events. Saharan dust also reaches the Jungfraujoch mainly during spring. For offline ice nucleation analysis in the laboratory under similar thermodynamic conditions, airborne dust was collected a) at Izaña with a cyclone directly from the air and b) collected from the surface of the Aletsch glacier close to the JFJ after deposition. Supporting measurements of aerosol particle size distributions and fluorescence were conducted at both locations, as well as cloud water isotope analysis at the Jungfraujoch and aerosol chemistry at Izaña. For both locations the origin of the INPs was investigated with a focus on dust and biological particles using back trajectories and chemical signature. Results show that dust aerosol is the dominant INP type at both locations at a temperature of 241 K. In addition to Saharan dust, also more local, basaltic dust is found at the Jungfraujoch. Biological particles are not observed to play a role for ice nucleation in clouds during winter at Jungfraujoch but are enriched in INP compared to the total aerosol at Izaña also during dust events. The comparison of the laboratory and the field measurements at Izaña indicates a good reproducibility of the field data by the collected dust samples. Field and laboratory data of the dust samples from both locations show that the dust arriving at JFJ is less ice nucleation active

  8. Effects of airborne particulate matter on the acidity of precipitation in central Missouri

    SciTech Connect

    Applin, K.R.

    1985-01-01

    The pH of rainfall in central Missouri was monitored at four sites during the fall of 1983. Several pH values were well above 5.6, the theoretical pH of pure water in equilibrium with ambient levels of CO/sub 2/. Most of the higher pH's were measured on rainfall of short duration or rainfall collected during the first few hours of extended rainfall events. Furthermore, the rainfall associated with storm events lasting several days exhibited a trend of decreasing pH with time approaching values as low as 4.0 during the late stages of rainfall. Precipitation pH values above 5.6 apparently reflect neutralization reactions between wet precipitation and various components of airborne dust, especially clays and carbonates. During extended rainfalls, the neutralization effects gradually diminish as suspended dust is washed from the atmosphere yielding more accurate values of the wet precipitation pH. The results of this study suggest that airborne particulate matter generated from the dust bowl region of the US may affect the chemistry of precipitation in areas hundreds of kilometers downwind. Using date available in the literature, a direct relationship between precipitation pH and accumulated dustfall was found for data taken along a transect which represents the path of major storms crossing the US, i.e., from the south-central to northeastern regions.

  9. Estimating factors to convert Chinese 'Total Dust' measurements to ACGIH respirable concentrations in metal mines and pottery industries.

    PubMed

    Gao, P; Chen, B T; Hearl, F J; McCawley, M A; Schwerha, D J; Odencrantz, J; Chen, W; Chen, J; Soderholm, S C

    2000-06-01

    Historical data on the dust exposures of Chinese workers in metal mines (iron/copper, tin, tungsten) and pottery industries are being used in an ongoing joint Chinese/United States epidemiological study to investigate the exposure-response relationship for the development of silicosis, lung cancer, and other diseases. The historical data include 'total dust' concentrations determined by a Chinese method. Information about particle size distribution and the chemical and mineralogical content of airborne particles is generally not available. In addition, the historical Chinese sampling strategy is different from a typical American eight-hour time-weighted average (TWA) sampling strategy, because the Chinese samples were collected for approximately 15 minutes during production so the sample could be compared to their maximum allowable concentration (MAC) standard. Therefore, in order to assess American respirable dust exposure standards in light of the Chinese experience, factors are needed to convert historical Chinese total dust concentrations to respirable dust concentrations. As a part of the joint study to estimate the conversion factors, airborne dust samples were collected in 20 metal mines and 9 pottery factories in China during 1988 and 1989 using three different samplers: 10mm nylon cyclones, multi-stage 'cassette' impactors, and the traditional Chinese total dust samplers. More than 100 samples were collected and analysed for each of the three samplers. The study yielded two different estimates of the conversion factor from the Chinese total dust concentrations (measured during production processes) to respirable dust concentrations. The multivariate analysis of variance (MANOVA) reveals that, with a fixed sampling/analysis method, conversion factors were not statistically different among the different job titles within each industry. It also indicates that conversion factors among the industries were not statistically different. However, the two estimates

  10. Atmospheric dust and acid rain

    SciTech Connect

    Hedin, L.O.; Likens, G.E.

    1996-12-01

    Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid rain and atmospheric dust? Suggestions range from the improbable to the feasible. One reasonable suggestion is to reduce emissions of acidic pollutants to levels that can be buffered by natural quantities of basic compounds in the atmosphere; such a goal would mean continued reductions in sulfur dioxide and nitrogen oxides, perhaps even greater than those prescribed in the 1990 Amendments to the Clean Air Act in the U.S. 5 figs.

  11. Dust Detector

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.

    2001-01-01

    We discuss a recent sounding rocket experiment which found charged dust in the Earth's tropical mesosphere. The dust detector was designed to measure small (5000 - 10000 amu.) charged dust particles, most likely of meteoric origin. A 5 km thick layer of positively charged dust was found at an altitude of 90 km, in the vicinity of an observed sporadic sodium layer and sporadic E layer. The observed dust was positively charged in the bulk of the dust layer, but was negatively charged near the bottom.

  12. The Lunar Environment: Determining the Health Effects of Exposure to Moon Dusts

    NASA Technical Reports Server (NTRS)

    Khan-Mayberry, Noreen

    2007-01-01

    The moon's surface is covered with a thin layer of fine, charged, reactive dust capable of layer of fine, charged, reactive dust capable of capable of entering habitats and vehicle compartments, where it can result in crewmember health problems. NASA formed the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to study the effects of exposure to Lunar Dust on human health. To date, no scientifically defensible toxicological studies have been performed on lunar dusts, specifically the determination of exposure limits and their affect on human health. The multi-center LADTAG (Lunar Airborne Dust Toxicology center LADTAG (Lunar Airborne Dust Toxicology Advisory Group) was formed in response to the Office of the Chief Health and Medical Office s (OCHMO) request to develop recommendations for defining risk (OCHMO) request to develop recommendations for defining risk defining risk criteria for human lunar dust exposure.

  13. Fingerprints in the Dust

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These MISR nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a spectacularly dusty spring view from April 7, 2001 (middle). The left-hand and middle images are from Terra orbits 2967 and 6928, respectively, and extend from central Manchuria near the top to portions of North and South Korea at the bottom. They are approximately 380 kilometers in width.

    Asia's desert areas are prone to soil erosion, as underground water tables are lowered by prolonged drought and by industrial and agricultural water use. Heavy winds blowing eastward across the arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the April 2001 storm blew across the Pacific Ocean and were carried as far as North America. The minerals transported in this manner are believed to provide nutrients for both oceanic and land ecosystems.

    According to the Xinhua News Agency in China, nearly one million tons of Gobi Desert dust blow into Beijing each year. During a similar dust outbreak last year, the Associated Press reported that the visibility in Beijing had been reduced the point where buildings were barely visible across city streets, and airline schedules were significantly disrupted. The dust has also been implicated in adverse health effects such as respiratory discomfort and eye irritation.

    The image on the right is a higher resolution MISR nadir-camera view of a portion of the April 7, 2001 dust cloud. It covers an area roughly 250 kilometers wide by 470 kilometers high. When viewed at full magnification, a number of atmospheric wave features, like the ridges and valleys of a fingerprint, are apparent. These are probably induced by surface topography, which can disturb the wind flow. A few small cumulus clouds are also visible, and are casting shadows on the thick lower dust layer.

    Analyses of images such as these constitute one phase of MISR

  14. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

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

  15. Continental-scale distributions of dust-associated bacteria and fungi.

    PubMed

    Barberán, Albert; Ladau, Joshua; Leff, Jonathan W; Pollard, Katherine S; Menninger, Holly L; Dunn, Robert R; Fierer, Noah

    2015-05-01

    It has been known for centuries that microorganisms are ubiquitous in the atmosphere, where they are capable of long-distance dispersal. Likewise, it is well-established that these airborne bacteria and fungi can have myriad effects on human health, as well as the health of plants and livestock. However, we have a limited understanding of how these airborne communities vary across different geographic regions or the factors that structure the geographic patterns of near-surface microbes across large spatial scales. We collected dust samples from the external surfaces of ∼1,200 households located across the United States to understand the continental-scale distributions of bacteria and fungi in the near-surface atmosphere. The microbial communities were highly variable in composition across the United States, but the geographic patterns could be explained by climatic and soil variables, with coastal regions of the United States sharing similar airborne microbial communities. Although people living in more urbanized areas were not found to be exposed to distinct outdoor air microbial communities compared with those living in more rural areas, our results do suggest that urbanization leads to homogenization of the airborne microbiota, with more urban communities exhibiting less continental-scale geographic variability than more rural areas. These results provide our first insight into the continental-scale distributions of airborne microbes, which is information that could be used to identify likely associations between microbial exposures in outdoor air and incidences of disease in crops, livestock, and humans. PMID:25902536

  16. Continental-scale distributions of dust-associated bacteria and fungi

    PubMed Central

    Barberán, Albert; Ladau, Joshua; Pollard, Katherine S.; Menninger, Holly L.; Dunn, Robert R.; Fierer, Noah

    2015-01-01

    It has been known for centuries that microorganisms are ubiquitous in the atmosphere, where they are capable of long-distance dispersal. Likewise, it is well-established that these airborne bacteria and fungi can have myriad effects on human health, as well as the health of plants and livestock. However, we have a limited understanding of how these airborne communities vary across different geographic regions or the factors that structure the geographic patterns of near-surface microbes across large spatial scales. We collected dust samples from the external surfaces of ∼1,200 households located across the United States to understand the continental-scale distributions of bacteria and fungi in the near-surface atmosphere. The microbial communities were highly variable in composition across the United States, but the geographic patterns could be explained by climatic and soil variables, with coastal regions of the United States sharing similar airborne microbial communities. Although people living in more urbanized areas were not found to be exposed to distinct outdoor air microbial communities compared with those living in more rural areas, our results do suggest that urbanization leads to homogenization of the airborne microbiota, with more urban communities exhibiting less continental-scale geographic variability than more rural areas. These results provide our first insight into the continental-scale distributions of airborne microbes, which is information that could be used to identify likely associations between microbial exposures in outdoor air and incidences of disease in crops, livestock, and humans. PMID:25902536

  17. Characterization of airborne particulates in Bangkok urban area by neutron activation analysis.

    PubMed

    Nouchpramool, S; Sumitra, T; Leenanuphunt, V

    1999-01-01

    Samples of airborne particulates were collected in a residential area and in an area near a busy highway in Bangkok during the period from January 1997 to May 1998. A stacked filter system was used for the former site and a Partisol 2000 was used for the latter site. Both 2.5 microns and 10-micron particulates were collected every week. The total suspended particulate matters were also collected at the latter site. The samples were analyzed by neutron activation analysis utilizing neutron flux from a 2-MW TRIGA MARK III research reactor. The elements most frequently detected in the airborne particulates were Al, As, Br, Ca, Ce, Cl, Co, Cr, Cs, Fe, I, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Th, Ti, V, and Zn. The enrichment factor and factor analysis were used to investigate trends, sources, and origin of the atmospheric aerosols. Anthropogenic elements in road dust, construction dust, motor vehicles emission, and other combustion components were identified. A comparative study of data between both sites was performed and it was found that the mass concentration in the area close to the highway was about three times higher than in the residential area. PMID:10676491

  18. SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH

    EPA Science Inventory

    Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (<_ 1....

  19. Tikhonravov Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located within a small crater inside Tikhonravov Crater.

    Image information: VIS instrument. Latitude 12.6, Longitude 37.1 East (322.9 West). 36 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located in a small canyon within a crater rim northeast of Naktong Vallis.

    Image information: VIS instrument. Latitude 7.1, Longitude 34.7 East (325.3 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Lycus Sulci Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches occur on the slopes of Lycus Sulci near Olympus Mons.

    Image information: VIS instrument. Latitude 28.1, Longitude 220.4 East (139.6 West). 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    This region of dust avalanches is located in and around a crater to the west of yesterday's image.

    Image information: VIS instrument. Latitude 14.7, Longitude 32.7 East (327.3 West). 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. Pulmonary and Systemic Immune Response to Chronic Lunar Dust Inhalation

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Quiriarte, Heather; Nelman, Mayra; Lam, Chiu-wing; James, John T.; Sams, Clarence

    2014-01-01

    Background: Due to millennia of meteorite impact with virtually no erosive effects, the surface of the Moon is covered by a layer of ultra-fine, reactive Lunar dust. Very little is known regarding the toxicity of Lunar dust on human physiology. Given the size and electrostatic characteristics of Lunar dust, countermeasures to ensure non-exposure of astronauts will be difficult. To ensure astronaut safety during any future prolonged Lunar missions, it is necessary to establish the effect of chronic pulmonary Lunar dust exposure on all physiological systems. Methods: This study assessed the toxicity of airborne lunar dust exposure in rats on pulmonary and system immune system parameters. Rats were exposed to 0, 20.8, or 60.8 mg/m3 of lunar dust (6h/d; 5d/wk) for up to 13 weeks. Sacrifices occurred after exposure durations of 1day, 7 days, 4 weeks and 13 weeks post-exposure, when both blood and lung lavage fluid were collected for analysis. Lavage and blood assays included leukocyte distribution by flow cytometry, electron/fluorescent microscopy, and cytokine concentration. Cytokine production profiles following mitogenic stimulation were performed on whole blood only. Results: Untreated lavage fluid was comprised primarily of pulmonary macrophages. Lunar dust inhalation resulted in an influx of neutrophils and lymphocytes. Although the percentage of lymphocytes increased, the T cell CD4:CD8 ratio was unchanged. Cytokine analysis of the lavage fluid showed increased levels of IL-1b and TNFa. These alterations generally persisted through the 13 week sampling. Blood analysis showed few systemic effects from the lunar dust inhalation. By week 4, the peripheral granulocyte percentage was elevated in the treated rats. Plasma cytokine levels were unchanged in all treated rats compared to controls. Peripheral blood analysis showed an increased granulocyte percentage and altered cytokine production profiles consisting of increased in IL-1b and IL-6, and decreased IL-2

  4. Design and development of a dust dispersion chamber to quantify the dispersibility of rock dust

    PubMed Central

    Perera, Inoka E.; Sapko, Michael J.; Harris, Marcia L.; Zlochower, Isaac A.; Weiss, Eric S.

    2015-01-01

    Dispersible rock dust must be applied to the surfaces of entries in underground coal mines in order to inert the coal dust entrained or made airborne during an explosion and prevent propagating explosions. 30 CFR. 75.2 states that “… [rock dust particles] when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air …” However, a proper definition or quantification of “light blast of air” is not provided. The National Institute for Occupational Safety and Health (NIOSH) has, consequently, designed a dust dispersion chamber to conduct quantitative laboratory-scale dispersibility experiments as a screening tool for candidate rock dusts. A reproducible pulse of air is injected into the chamber and across a shallow tray of rock dust. The dust dispersed and carried downwind is monitored. The mass loss of the dust tray and the airborne dust measurements determine the relative dispersibility of the dust with respect to a Reference rock dust. This report describes the design and the methodology to evaluate the relative dispersibility of rock dusts with and without anti-caking agents. Further, the results of this study indicate that the dispersibility of rock dusts varies with particle size, type of anti-caking agent used, and with the untapped bulk density. Untreated rock dusts, when wetted and dried forming a cake that was much less dispersible than the reference rock dust used in supporting the 80% total incombustible content rule. PMID:26834390

  5. Lung dust and lung iron contents of coal workers in different coalfields in Great Britain

    PubMed Central

    Bergman, I.; Casswell, C.

    1972-01-01

    Bergman, I., and Casswell, C. (1972).Brit. J. industr. Med.,29, 160-168. Lung dust and lung iron contents of coal workers in different coalfields in Great Britain. Lung dust analyses from seven coalfields are studied and it is found that the average dust composition varies significantly with the rank of coal. The higher the rank, the higher the coal percentage and the lower the quartz percentage of the lung dust. This holds for all coalfields except in Scotland, where the lung dust contains mainly soot instead of coal. Samples of airborne dust collected at the coalface in different coalfields show a similar but small variability of composition with rank of coal, and the results from Scotland are in good agreement with the results from other coalfields. The amount of iron in simple pneumoconiosis lungs is related to their mineral and coal contents and to the factor `years underground'. The strongest relationship is with coal and mineral for coalface workers from England. For pit accident cases (all simple pneumoconiosis) mineral is important as well as years underground, while for simple pneumoconiosis cases from Scotland, years underground is the most important factor. PMID:4336667

  6. Professional exposure to basaltic rock dust: assessment by the Vibrio fischeri ecotoxicological test

    PubMed Central

    2013-01-01

    Background A recent study demonstrates that inhalation of airborne particulate from Mount Etna eruptions may induce fibrotic lung disease. The occupational exposure of construction workers from the Etna area, who excavate building sites and use basalt dust to make mortar, has never been assessed. Methods Samples of basalt, volcanic ash, basalt + cement and cement dust were collected on the construction site of a subway tunnel, ground to dust and subjected to the Microtox® solid-phase test to evaluate the toxicity of dust suspensions. Samples were investigated by scanning electron microscopy equipped with energy dispersive X-ray analysis (EDX). Minerals were identified and characterized by their morphology and elemental composition. Results The elements found most frequently were C, Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe and O. All four dusts were toxic: basalt and ash were significantly less toxic than basalt + cement and cement, which shared a similar and very high degree of toxicity. Higher Fe, Ca and Mg concentrations were associated with greater toxicity. Conclusions The risk related to long-term occupational exposure to various dusts on constructions sites in the Mount Etna area should be further assessed. PMID:24128058

  7. Investigating the Present Day Cosmic Dust Flux at the Earth's Surface: Initial Results from the Kwajalein Micrometeorite Collection

    NASA Technical Reports Server (NTRS)

    Wozniakiewicz, P. J.; Bradley, J. P.; Price, M. C.; Zolensky, M. E.; Ishii, H. A.; Brownlee, D. E.; Russell, S. S.

    2014-01-01

    Examination of impact craters on the Long Duration Exposure Facility satellite indicate a present day micrometeoroid flux of approx. 30,000 tonnes [1 after 2]. But what portion of this material arrives at the Earth's surface as micrometeorites? Studies of available micrometeorite collections from deep sea sediments [e.g. 3], Greenland blue ice [e.g. 4] and the South Pole water well [e.g. 1] may be complicated by terrestrial weathering and, in some cases, collection bias (magnetic separation for deep sea sediments) and poorly constrained ages. We have recently set up a micrometeorite collection station on Kwajalein Island in the Republic of the Marshall Islands in the Pacific Ocean, using high volume air samplers to collect particles directly from the atmosphere. By collecting in this way, the terrestrial age of the particles is known, the weathering they experience is minimal, and we are able to constrain particle arrival times. Collecting at this location also exploits the considerably reduced anthropogenic background [5]. Method: High volume air samplers were installed on top of the two-story airport building on Kwajalein. These were fitted with polycarbonate membrane filters with 5µm diameter perforations. The flow rates were set to 0.5m3/min, and filters were changed once a week. After collection, filters were washed to remove salt and concentrate particles [see 5] in preparation for analysis by SEM. Results and Discussion: A selection of filters have been prepared and surveyed. Due to their ease of identification our initial investigations have focused on particles resembling cosmic spherules. The spheres can be divided into three main groups: 1. Silicate spherules rich in Al, Ca, K and Na (to varying degrees), 2. Silicate spherules rich in Mg and Fe and 3. Fe-rich spherules. Group 1 spherules are often vesiculated and can occur as aggregates. They are similar in appearance and composition to volcanic microspheres [e.g. 6] and are thus likely terrestrial in

  8. Modeling for Airborne Contamination

    SciTech Connect

    F.R. Faillace; Y. Yuan

    2000-08-31

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

  9. Airborne Submillimeter Spectroscopy

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    1998-01-01

    This is the final technical report for NASA-Ames grant NAG2-1068 to Caltech, entitled "Airborne Submillimeter Spectroscopy", which extended over the period May 1, 1996 through January 31, 1998. The grant was funded by the NASA airborne astronomy program, during a period of time after the Kuiper Airborne Observatory was no longer operational. Instead. this funding program was intended to help develop instrument concepts and technology for the upcoming SOFIA (Stratospheric Observatory for Infrared Astronomy) project. SOFIA, which is funded by NASA and is now being carried out by a consortium lead by USRA (Universities Space Research Association), will be a 747 aircraft carrying a 2.5 meter diameter telescope. The purpose of our grant was to fund the ongoing development of sensitive heterodyne receivers for the submillimeter band (500-1200 GHz), using sensitive superconducting (SIS) detectors. In 1997 July we submitted a proposal to USRA to construct a heterodyne instrument for SOFIA. Our proposal was successful [1], and we are now continuing our airborne astronomy effort with funding from USRA. A secondary purpose of the NAG2-1068 grant was to continue the anaIN'sis of astronomical data collected with an earlier instrument which was flown on the NASA Kuiper Airborne Observatory (KAO). The KAO instrument and the astronomical studies which were carried out with it were supported primarily under another grant, NAG2-744, which extended over October 1, 1991 through Januarv 31, 1997. For a complete description of the astronomical data and its anailysis, we refer the reader to the final technical report for NAG2-744, which was submitted to NASA on December 1. 1997. Here we report on the SIS detector development effort for SOFIA carried out under NAG2-1068. The main result of this effort has been the demonstration of SIS mixers using a new superconducting material niobium titanium nitride (NbTiN), which promises to deliver dramatic improvements in sensitivity in the 700

  10. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    article title:  Massive Dust Storm over Australia     View ... at JPL September 22, 2009 - Massive dust storm over Australia. project:  MISR category:  ... Sep 22, 2009 Images:  Dust Storm location:  Australia and New Zealand ...

  11. Stable carbon and nitrogen isotopic compositions of ambient aerosols collected from Okinawa Island in the western North Pacific Rim, an outflow region of Asian dusts and pollutants

    NASA Astrophysics Data System (ADS)

    Kunwar, Bhagawati; Kawamura, Kimitaka; Zhu, Chunmao

    2016-04-01

    Stable carbon (δ13C) and nitrogen (δ15N) isotope ratios were measured for total carbon (TC) and nitrogen (TN), respectively, in aerosol (TSP) samples collected at Cape Hedo, Okinawa, an outflow region of Asian pollutants, during 2009-2010. The averaged δ13C and δ15N ratios are -22.2‰ and +12.5‰, respectively. The δ13C values are similar in both spring (-22.5‰) and winter (-22.5‰), suggesting the similar sources and/or source regions. We found that δ13C from Okinawa aerosols are ca. 2‰ higher than those reported from Chinese megacities probably due to photochemical aging of organic aerosols. A strong correlation (r = 0.81) was found between nss-Ca and TSP, suggesting that springtime aerosols are influenced from Asian dusts. However, carbonates in the Asian dusts were titrated with acidic species such as sulfuric acid and oxalic acid during atmospheric transport although two samples suggested the presence of remaining carbonate. No correlations were found between δ13C and tracer compounds (levoglucosan, elemental carbon, oxalic acid, and Na+). During winter and spring, coal burning is significant source in China. Based on isotopic mass balance, contribution of coal burning origin particles to total aerosol carbon was estimated as ca. 97% in winter, which is probably associated with the high emissions in China. Contribution of NO3- to TN was on average 45% whereas that of NH4+ was 18%. These results suggest that vehicular exhaust is an important source of TN in Okinawa aerosols. Concentration of water-soluble organic nitrogen (WSON) is higher in summer, suggesting that WSON is more emitted from the ocean in warmer season whereas inorganic nitrogen is more emitted in winter and spring from pollution sources in the Asian continent.

  12. Bacterial diversity and composition during rain events with and without Saharan dust influence reaching a high mountain lake in the Alps.

    PubMed

    Peter, Hannes; Hörtnagl, Paul; Reche, Isabel; Sommaruga, Ruben

    2014-12-01

    The diversity of airborne microorganisms that potentially reach aquatic ecosystems during rain events is poorly explored. Here, we used a culture-independent approach to characterize bacterial assemblages during rain events with and without Saharan dust influence arriving to a high mountain lake in the Austrian Alps. Bacterial assemblage composition differed significantly between samples with and without Saharan dust influence. Although alpha diversity indices were within the same range in both sample categories, rain events with Atlantic or continental origins were dominated by Betaproteobacteria, whereas those with Saharan dust intrusions were dominated by Gammaproteobacteria. The high diversity and evenness observed in all samples suggests that different sources of bacteria contributed to the airborne assemblage collected at the lake shore. During experiments with bacterial assemblages collected during rain events with Saharan dust influence, cell numbers rapidly increased in sterile lake water from initially ∼3 × 103 cell ml-1 to 3.6-11.1 x105 cells ml-1 within 4-5 days, and initially, rare taxa dominated at the end of the experiment. Our study documents the dispersal of viable bacteria associated to Saharan dust intrusions travelling northwards as far as 47° latitude.

  13. Bacterial diversity and composition during rain events with and without Saharan dust influence reaching a high mountain lake in the Alps

    PubMed Central

    Peter, Hannes; Hörtnagl, Paul; Reche, Isabel; Sommaruga, Ruben

    2016-01-01

    Summary The diversity of airborne microorganisms that potentially reach aquatic ecosystems during rain events is poorly explored. Here, we used a culture-independent approach to characterize bacterial assemblages during rain events with and without Saharan dust influence arriving to a high mountain lake in the Austrian Alps. Bacterial assemblage composition differed significantly between samples with and without Saharan dust influence. Although alpha diversity indices were within the same range in both sample categories, rain events with Atlantic or continental origins were dominated by Betaproteobacteria, whereas those with Saharan dust intrusions were dominated by Gammaproteobacteria. The high diversity and evenness observed in all samples suggests that different sources of bacteria contributed to the airborne assemblage collected at the lake shore. During experiments with bacterial assemblages collected during rain events with Saharan dust influence, cell numbers rapidly increased in sterile lake water from initially ~3 × 103 cell ml−1 to 3.6–11.1 × 105 cells ml−1 within 4–5 days, and initially, rare taxa dominated at the end of the experiment. Our study documents the dispersal of viable bacteria associated to Saharan dust intrusions travelling northwards as far as 47° latitude. PMID:25756115

  14. Status and Future of Dust Storm Forecasting

    NASA Astrophysics Data System (ADS)

    Westphal, D. L.

    2002-12-01

    In recent years, increased attention has been given to the large amounts of airborne dust derived from the deserts and desertified areas of the world and transported over scales ranging from local to global. This dust can have positive and negative impacts on human activities and the environment, including modifying cloud formation, fertilizing the ocean, degrading air quality, reducing visibility, transporting pathogens, and inducing respiratory problems. The atmospheric radiative forcing by the dust has implications for global climate change and presently is one of the largest unknowns in climate models. These uncertainties have lead to much of the funding for research into the sources, properties, and fate of atmospheric dust. As a result of advances in numerical weather prediction over the past decades and the recent climate research, we are now in a position to produce operational dust storm forecasts. International organizations and national agencies are developing programs for dust forecasting. The approaches and applications of dust detection and forecasting are as varied as the nations that are developing the models. The basic components of a dust forecasting system include atmospheric forcing, dust production, and dust microphysics. The forecasting applications include air and auto traffic safety, shipping, health, national security, climate and weather. This presentation will summarize the methods of dust storm forecasting and illustrate the various applications. The major remaining uncertainties (e.g. sources and initialization) will be discussed as well as approaches for solving those problems.

  15. Planetary Dust: Cross-Functional Considerations

    NASA Technical Reports Server (NTRS)

    Wagner, Sandra

    2006-01-01

    Apollo astronauts learned first hand how problems with dust impact lunar surface missions. After three days, lunar dust contaminating on EVA suit bearings led to such great difficulty in movement that another EVA would not have been possible. Dust clinging to EVA suits was transported into the Lunar Module. During the return trip to Earth, when microgravity was reestablished, the dust became airborne and floated through the cabin. Crews inhaled the dust and it irritated their eyes. Some mechanical systems aboard the spacecraft were damaged due to dust contamination. Study results obtained by Robotic Martian missions indicate that Martian surface soil is oxidative and reactive. Exposures to the reactive Martian dust will pose an even greater concern to the crew health and the integrity of the mechanical systems. As NASA embarks on planetary surface missions to support its Exploration Vision, the effects of these extraterrestrial dusts must be well understood and systems must be designed to operate reliably and protect the crew in the dusty environments of the Moon and Mars. The AIM Dust Assessment Team was tasked to identify systems that will be affected by the respective dust, how they will be affected, associated risks of dust exposure, requirements that will need to be developed, identified knowledge gaps, and recommended scientific measurements to obtain information needed to develop requirements, and design and manufacture the surface systems that will support crew habitation in the lunar and Martian outposts.

  16. Dust Mitigation for Martian Exploration

    NASA Technical Reports Server (NTRS)

    Williams, Blakeley Shay

    2011-01-01

    One of the efforts of the In-Situ Resource Utilization project is to extract oxygen, fuel, and water from the Martian air. However, the surface of Mars is covered in a layer of dust, which is uploaded into the atmosphere by dust devils and dust storms. This atmospheric dust would be collected along with the air during the conversion process. Thus, it is essential to extract the dust from the air prior to commencing the conversion. An electrostatic precipitator is a commonly used dust removal technology on earth. Using this technology, dust particles that pass through receive an electrostatic charge by means of a corona discharge. The particles are then driven to a collector in a region of high electric field at the center of the precipitator. Experiments were conducted to develop a precipitator that will function properly in the Martian atmosphere, which has a very low pressure and is made up . of primarily carbon dioxide.

  17. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

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

  18. Manganese survey in airborne particulate matter from a mining area at Hidalgo State, Mexico

    NASA Astrophysics Data System (ADS)

    Aldape, F.; Hernández-Méndez, B.; Flores M, J.

    1999-04-01

    A manganese (Mn) survey in airborne particulate matter from a mining area located in Hidalgo State (Mexico) was performed using PIXE. Deposits of Mn ore, first discovered in 1959 and under continuous exploitation since 1962, are nowadays considered as one of the most important of their kind in the American Continent. Afterwards, local inhabitants have been under continuous overexposure to dusts and water highly enriched with Mn. Since no information was available about Mn content in airborne particulate matter in that area, especially in the respirable fraction PM 2.5, airborne particles were collected simultaneously at two sites located on opposite sides of the rim of the mining valley, and along the line of prevailing local winds. The sample collection was performed on eight alternate days, taking two samples per day (day-time and night-time) at each sampling site, using Stacked Filter Units (SFUs) of the Davis design to separate particles into fine (PM 2.5) and coarse (PM 15) sizes. The samples were PIXE analyzed and the results of this study revealed that Mn content, in both fine and coarse fractions, were in excess of the general urban background level of 40 ng/m 3 (US Environmental Protection Agency, 1990) in more than 50% of the samples, which indicate severe environmental deterioration in the place under study.

  19. Mapping of Fugitive Dust Generation, Transport, and Deposition in the Nogales, Arizona Region Using Enhanced Thematic Mapper Plus (ETM+) Data

    NASA Astrophysics Data System (ADS)

    Stefanov, W. L.; Stefanov, W. L.; Ramsey, M. S.; Christensen, P. R.

    2001-05-01

    Urban centers located along the U.S.-Mexico border represent significant sources of fugitive (airborne) dust. This dust, which can lead to adverse health effects, arises from several factors including construction activities related to land use conversion (i.e., agricultural to residential), unpaved roadways, agricultural activities, and human disturbance of the soil. Fundamental baseline data needed for modeling and monitoring of particulate generation and transport are accurate regional classification of land cover, degree of disturbance, and a metric of land cover change. Identification and delineation of fugitive dust source regions using a purely field-based approach is time and labor intensive and can lead to errors over time as land use changes. Further, restrictions on access to specific areas (such as private lands and reservations) may impede or prevent site investigations in these areas. Remotely gathered information can be used to circumvent these difficulties and provide rapid dust source region identification with quantitative area measurements required in transport models. Landsat ETM+ data was used to identify and delineate surficial materials that were either potential fugitive dust source regions or were important factors in dust transport and deposition. Using a knowledge-based system, land cover was classified into three generalized types: natural and disturbed soils (dust generation sites); asphalt, concrete, and urban materials (dust transport areas); and vegetated areas (dust deposition sites). Accuracy of the land cover classification was assessed using field verification, comparison of field and image reflectance spectra, and digital aerial orthophotographs. Results of image classification and field verification for Landsat data acquired during the winter of 2000 show a strong correlation, and will be used with data collected during the summer dry season for change detection analysis. The digital format of the classified data is optimal for

  20. Laboratory studies of interplanetary dust

    NASA Technical Reports Server (NTRS)

    Walker, R. M.

    1986-01-01

    Interplanetary dust particles (IDPs) are a form of primitive extraterrestrial material. In spite of the formidable experimental problems in working with particles that are too small to be seen with the naked eye, it has proven possible to obtain considerable information concerning their properties and possible origins. Dust particles collected in the stratosphere were reviewed. These particles are the best available samples of interplanetary dust and were studied using a variety of analytical techniques.

  1. The global transport of dust

    USGS Publications Warehouse

    Griffin, Dale W.; Kellogg, C.A.; Garrison, V.H.; Shinn, E.A.

    2002-01-01

    By some estimates as much as two billion metric tons of dust are lifted into the Earth's atmosphere every year. Most of this dust is stirred up by storms, the more dramatic of which are aptly named dust storms. But more than mere dirt is carried aloft. Drifting with the suspended dust particles are soil pollutants such as herbicides and pesticides and a significant number of microorganisms-bacteria, viruses and fungi. We can gain some appreciation of how much microbial life is actually floating in our atmosphere by performing a quick calculation. There are typically about one million bacteria per gram of soil, but let's be conservative and suppose there are only 10,000 bacteria per gram of airborne sediment. Assuming a modest one billion metric tons of sediment in the atmosphere, these numbers translate into a quintillion (1018) sediment-borne bacteria moving around the planet each year-enough to form a microbial bridge between Earth and Jupiter. Here we consider what we've learned about the airborne transport of sediment across the globe, and review some of the remarkable studies in this reemerging field that had it origins more than 100 years ago.

  2. Relating Optical Properties of Dusts to their Mineralogical and Physical Interrelationships

    NASA Astrophysics Data System (ADS)

    Engelbrecht, J. P.; Moosmuller, H.; Jayanty, R. K. M.; Casuccio, G.; Pincock, S. L.

    2015-12-01

    The purpose of the project was to provide information on the mineralogical, chemical and physical interrelationships of re-suspended mineral dust samples collected as grab samples from global dust sources. Surface soil samples were collected from about 65 desert sites, including the southwestern USA (12), Mali (3), Chad (3), Morocco (1), Canary Islands (8), Cape Verde (1), Djibouti (1), Afghanistan (3), Iraq (6), Kuwait (5), Qatar (1), UAE (1), Serbia (3), China (5), Namibia (3), Botswana (4), Australia (3), and Chile (1). The < 38 μm sieved fraction of each sample was re-suspended in an entrainment chamber, from which the airborne mineral dust could be monitored, sampled and analyzed. Instruments integrated into the entrainment facility included two PM10 and two PM2.5 filter samplers, a beta attenuation gauge for the continuous measurement of PM10 and PM2.5particulate mass fractions, an aerodynamic particle size (APS) analyzer, and a three wavelength (405, 532, 781nm) photoacoustic resonator with integrating reciprocal nephelometer for monitoring absorption and scattering coefficients during the dust re-suspension process. Filter sample media included Teflon® membrane and quartz fiber filters for chemical analysis (71 species), and Nuclepore® filters for individual particle analysis by Scanning Electron Microscopy (SEM). The < 38 μm sieved fractions were also analyzed by X-ray diffraction for their mineral content while the > 38 μm, < 125 μm soil fractions were mineralogically characterized by optical microscopy. We will be presenting results on the optical measurements, also showing the relationship between single scattering albedo (SSA) at three different wavelengths, and chemical as well as mineralogical content and interdependencies of the entrained dust samples. Examples showing the relationships between the single scattering albedos of airborne dusts, and iron (Fe) in hematite, goethite, and clay minerals (montmorillonite, illite, palygorskite), will

  3. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, Dániel; Lauretta, Dante S.

    2010-01-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  4. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, D.´niel; Lauretta, Dante S.

    2014-02-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  5. Coupling Mars' Dust and Water Cycles: Effects on Dust Lifting Vigor, Spatial Extent and Seasonality

    NASA Technical Reports Server (NTRS)

    Kahre, M. A.; Hollingsworth, J. L.; Haberle, R. M.; Montmessin, F.

    2012-01-01

    The dust cycle is an important component of Mars' current climate system. Airborne dust affects the radiative balance of the atmosphere, thus greatly influencing the thermal and dynamical state of the atmosphere. Dust raising events on Mars occur at spatial scales ranging from meters to planet-wide. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. Generally, a low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading were observed by MGS/TES: one peak occurred before northern winter solstice at Ls 200-240, and one peak occurred after northern winter solstice at L(sub s) 305-340. These maxima in dust loading are thought to be associated with transient eddy activity in the northern hemisphere, which has been observed to maximize pre- and post-solstice. Interactive dust cycle studies with Mars General Circulation Models (MGCMs) have included the lifting, transport, and sedimentation of radiatively active dust. Although the predicted global dust loadings from these simulations capture some aspects of the observed dust cycle, there are marked differences between the simulated and observed dust cycles. Most notably, the maximum dust loading is robustly predicted by models to occur near northern winter solstice and is due to dust lifting associated with down slope flows on the flanks of the Hellas basin. Thus far, models have had difficulty simulating the observed pre- and post- solstice peaks in dust loading. Interactive dust cycle studies typically have not included the formation of water ice clouds or their radiative effects. Water ice clouds can influence the dust cycle by scavenging dust from atmosphere and by interacting with solar and infrared radiation

  6. Remote Sensing of Mineral Dust Sources (Invited)

    NASA Astrophysics Data System (ADS)

    Sprigg, W. A.; Morain, S. A.

    2009-12-01

    Thirty-four percent of Earth's land surface is arid, home to two billion people routinely exposed to airborne dust and increased risk of cardiovascular and respiratory disease. The NASA-supported Public Health Applications in Remote Sensing project has improved the process of simulating and predicting when and where dust storms will occur and the consequent particulate air quality. Partnerships with state public health offices test model products for epidemiological and health surveillance applications. The key to significant improvement in simulations, forecasts and their use has been identifying and monitoring mineral dust sources via satellite based sensors.

  7. Quantitation of major allergens in dust samples from urban populations collected in different seasons in two climatic areas of the Basque region (Spain).

    PubMed

    Echechipía, S; Ventas, P; Audícana, M; Urrutia, I; Gastaminza, G; Polo, F; Fernández de Corres, L

    1995-06-01

    We present the results of allergen content evaluation in 80 dust samples from 31 homes of atopic patients from two climatic areas (humid and subhumid), collected in two seasons of the year (autumn and winter). Monoclonal antibody-based immunoassays were used to quantify Der p 1, Der f 1, Der 2, Lep d 1, and Fel d 1. The results were compared according to climate, season, and the type of sensitization (Pyroglyphidae mites, storage mites, or grass pollens). We underline the predominance of Dermatophagoides pteronyssinus (89% of samples) over D. farinae (16% of samples) in our environment. Der p 1 rates were higher in the humid area (Mann-Whitney P < 0.001), especially in the autumn (Wilcoxon P < 0.05). Lep d 1 was detected in 23% of samples and Lep d 1 levels were higher in the homes of patients sensitized to storage mites (Mann-Whitney P < 0.05), whereas this allergen was not detected in the homes of pollen-allergic patients. Fel d 1 was detected in nine of the 31 homes (16% of samples) although there was a cat in only one home. PMID:7573840

  8. Optical dust sensor for the mining industry

    NASA Astrophysics Data System (ADS)

    Sierakowski, Marek W.; Wolinski, Tomasz R.; Domanski, Andrzej W.; Osinska, Katarzyna

    2003-04-01

    One of many hazards in mining industry is presence of airborne dust on underground boards. Hazards caused by dust generated and spread in mines are of the two types: (1) health risk for miners from airborne dust produced from rocks, coal, soluble minerals (pneumoconiosis, toxicity), (2) danger of explosion of carbon dust. Dust particles produced in mines underground range from 0 to about 400 micrometers, have irregular shapes and prevailingly are strongly light absorbing. It is assumed that the most health-risky are particles between 1 μm and 5 μm in size. They are not visible with naked eyes, so their control and measurement need technical equipment. As a standard in polish mines, gravimetric measurement method is used at present. This method works well in post-event evaluation of total health-risk factor, but is not much useful for instantaneous risk warning. In order to recognize and possibly prevent the dust risk as it appears, other methods have to be used, like optical method. Looking towards this demand, an experimental optical dust sensor is demonstrated. The sensor is based on light scattering effect by dust particles, as usual do devices of this type. Originality of this solution lies in construction details of the sensor. Scattering is a complex function of dust kind, size, shape and concentration. Moreover, operating conditions of such a device are cruel -- humidity, elevated temperature, vibrations, and over-all contact with dust -- are harmful for optics. Thus, to achieve reliable indications of the sensor is really a challenge. This paper describes optical construction attempting to overcome difficulties in obtaining dust concentration sensor intended for mining industry and similar applications. First laboratory and operational tests are also reported.

  9. PHARUS airborne SAR concept

    NASA Astrophysics Data System (ADS)

    Snoeij, Paul; Pouwels, Henk; Koomen, Peter J.; Hoogeboom, Peter

    1995-11-01

    PHARUS (phased array universal SAR) is an airborne SAR concept which is being developed in the Netherlands. The PHARUS system differs from other airborne SARs by the use of a phased array antenna, which provides both for the flexibility in the design as well as for a compact, light-weight instrument that can be carried on small aircraft. The concept allows for the construction of airborne SAR systems on a common generic basis but tailored to specific user needs and can be seen as a preparation for future spaceborne SAR systems using solid state transmitters with electronically steerable phased array antenna. The whole approach is aimed at providing an economic and yet technically sophisticated solution to remote sensing or surveying needs of a specific user. The solid state phased array antenna consists of a collection of radiating patches; the design flexibility for a large part resides in the freedom to choose the number of patches, and thereby the essential radar performance parameters such as resolution and swath width. Another consequence of the use of the phased array antenna is the system's compactness and the possibility to rigidly mount it on a small aircraft. The use of small aircraft of course considerably improves the cost/benefit ratio of the use of airborne SAR. Flight altitude of the system is flexible between about 7,000 and 40,000 feet, giving much operational freedom within the meteo and airspace control limits. In the PHARUS concept the airborne segment is complemented by a ground segment, which consists of a SAR processor, possibly extended by a matching image processing package. (A quick look image is available in real-time on board the aircraft.) The SAR processor is UNIX based and runs on easily available hardware (SUN station). Although the additional image processing software is available, the SAR processing software is nevertheless designed to be able to interface with commercially available image processing software, as well as being able

  10. Characterization of springtime airborne particulate matter-bound reactive oxygen species in Beijing.

    PubMed

    Liu, Qingyang; Zhang, Yuanxun; Liu, Yanju; Zhang, Meigen

    2014-01-01

    Epidemiologic studies have suggested that particulate matter (PM)-associated adverse health effects are related to particle composition. To study the toxicological characteristics of dust storm, airborne PM10 was collected at two sites in Beijing from March to May 2012. The production of reactive oxygen species (ROS), quantified by dithiothreitol (DTT), was used to measure the PM-induced oxidative potential. Two dust storm (DS) samples were monitored during the sampling period: one happened on March 28th (DS1) and the other one was on April 28th (DS2). The backward trajectory results showed that both events originated from Inner Mongolia and Mongolia, respectively. The increased trends of ROS activities during the dust storm episode in PM10 were observed for all the dust storms owing to a higher concentration of water-soluble components for all the PM10 samples compared to nondust storm ones. Interestingly, the correlations between DTT consumption with water-soluble species yield interesting results about the spatial variability of redox activity between sites. In particular, a tracer of soil suspension, namely Fe, contributed the most fraction to ROS variability in the urban background site. Water-soluble organic carbon (WSOC) made the highest contribution to ROS variability, suggesting that vehicle emission might be important driving factors of the PM-induced oxidative stress in the urban site. PMID:24728573

  11. Systematic Relationships Between Lidar Observables And Sizes And Mineral Composition Of Dust Aerosols

    NASA Astrophysics Data System (ADS)

    van Diedenhoven, B.; Perlwitz, J. P.; Fridlind, A. M.; Chowdhary, J.; Cairns, B.; Stangl, A. J.

    2015-12-01

    The physical and chemical properties of soil dust aerosol particles fundamentally affect their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates on the surface of dust particles, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Lidar measurements, such as extinction-to-backscatter, color and depolarization ratios, are frequently used to distinguish between aerosol types with different physical and chemical properties. The chemical composition of aerosol particles determines their complex refractive index, hence affecting their backscattering properties. Here we present a study on how dust aerosol backscattering and depolarization properties at wavelengths of 355, 532 and 1064 nm are related to size and complex refractive index, which varies with the mineral composition of the dust. Dust aerosols are represented by collections of spheroids with a range of prolate and oblate aspect ratios and their optical properties are obtained using T-matrix calculations. We find simple, systematic relationships between lidar observables and the dust size and complex refractive index that may aid the use of space-based or airborne lidars for direct retrieval of dust properties or for the evaluation of chemical transport models using forward simulated lidar variables. In addition, we present first results on the spatial variation of forward-simulated lidar variables based on a dust model that accounts for the atmospheric cycle of eight different mineral types plus internal mixtures of seven mineral types with iron oxides, which was recently implemented in the NASA GISS Earth System ModelE2.

  12. The Electrical Structure of Terrestrial Dust Devils: Implications of Multiple Vertical Measurements of the Electric Field

    NASA Astrophysics Data System (ADS)

    Delory, G. T.; Farrell, W. M.; Hillard, B.; Renno, N. O.; Smith, P.; Marshall, J. R.; Eatchel, A.

    2002-12-01

    In this work we discuss observations of the electrical structure of dust devils made in the summer of 2001 and 2002 during the Mars Atmosphere and Dust in the Optical and Radio (MATADOR) field campaign outside of Tucson, Arizona. While it has long been known that Terrestrial dust devils can support large electric fields of magnitudes of up to 10 kV/m or more, the fundamental features of the charging mechanism have yet to be fully characterized from an observational perspective. If triboelectric charging is indeed responsible for the generation of significant electric potentials within the dust column, some means of large scale stratification and/or separation of charges is necessary to maintain these fields. To help address this question and elucidate the overall vertical charge distribution of dust devils, we used two field mill instruments to make simultaneous measurements of electric fields both at the surface and 1 meter above the ground. At present, our observations indicate that the dust grains become negatively charged at or very near the air-surface interface. The largest devils recorded (30 m diameter) show a region of enhanced positive electric fields persisting for minutes after the event has passed, indicating the possible presence of a large scale collection of airborne positive charges following the negatively charged dust column. Based on our observations, the key to the charging mechanism appears to reside in the bottom of the saltation layer where the bulk of collisional frictional charging is likely to occur. We discuss the implications of these observations for theories of Terrestrial dust devil electrification and for our understanding of similar processes on Mars.

  13. Systematic Relationships Between Lidar Observables and Sizes And Mineral Composition Of Dust Aerosols

    NASA Technical Reports Server (NTRS)

    Van Diedenhoven, Bastiaan; Stangl, Alexander; Perlwitz, Jan; Fridlind, Ann M.; Chowdhary, Jacek; Cairns, Brian

    2015-01-01

    The physical and chemical properties of soil dust aerosol particles fundamentally affect their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates on the surface of dust particles, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Lidar measurements, such as extinction-to-backscatter, color and depolarization ratios, are frequently used to distinguish between aerosol types with different physical and chemical properties. The chemical composition of aerosol particles determines their complex refractive index, hence affecting their backscattering properties. Here we present a study on how dust aerosol backscattering and depolarization properties at wavelengths of 355, 532 and 1064 nm are related to size and complex refractive index, which varies with the mineral composition of the dust. Dust aerosols are represented by collections of spheroids with a range of prolate and oblate aspect ratios and their optical properties are obtained using T-matrix calculations. We find simple, systematic relationships between lidar observables and the dust size and complex refractive index that may aid the use of space-based or airborne lidars for direct retrieval of dust properties or for the evaluation of chemical transport models using forward simulated lidar variables. In addition, we present first results on the spatial variation of forward-simulated lidar variables based on a dust model that accounts for the atmospheric cycle of eight different mineral types plus internal mixtures of seven mineral types with iron oxides, which was recently implemented in the NASA GISS Earth System ModelE2.

  14. Dust control research for SEI. [Space Exploration Initiative

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.; Harris, Jeffrey R.

    1992-01-01

    A study, at NASA Johnson Space Center, of dust control requirements for surface habitats has focused on identification of the dust problem, identifying dust control techniques and dust control technology areas requiring research development. This research was performed for the Surface Habitats and Construction (SHAC) technology area. Dust control consists of two problems: (1) how to keep it out of the habitat; and (2) once the habitat or airlock is contaminated with dust, how to collect it. This paper describes the dust environment, the Apollo experience and dust control methods used, future EVA operational considerations, and dust control concepts for surface habitats.

  15. Rocket dust storms and detached dust layers in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Spiga, Aymeric; Faure, Julien; Madeleine, Jean-Baptiste; Määttänen, Anni; Forget, François

    2013-04-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling that includes the transport of radiatively active dust to predict the evolution of a local dust storm monitored by OMEGA on board Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, rather than by latent heating as in moist convection on Earth. We propose to use the terminology "rocket dust storm," or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30-50 km). Combined to horizontal transport by large-scale winds, rocket dust storms produce detached layers of dust reminiscent of those observed with Mars Global Surveyor and Mars Reconnaissance Orbiter. Since nighttime sedimentation is less efficient than daytime convective transport, and the detached dust layers can convect during the daytime, these layers can be stable for several days. The peak activity of rocket dust storms is expected in low-latitude regions at clear seasons (late northern winter to late northern summer), which accounts for the high-altitude tropical dust maxima unveiled by Mars Climate Sounder. Dust-driven deep convection has strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.

  16. Interactions Between Mineral Dust, Climate, and Ocean Ecosystems

    NASA Technical Reports Server (NTRS)

    Gasso, Santiago; Grassian, Vicki H.; Miller, Ron L.

    2010-01-01

    Over the past decade, technological improvements in the chemical and physical characterization of dust have provided insights into a number of phenomena that were previously unknown or poorly understood. In addition, models are now incorporating a wider range of physical processes, which will allow us to better quantify the climatic and ecological impacts of dust. For example, some models include the effect of dust on oceanic photosynthesis and thus on atmospheric CO 2 (Friedlingstein et al. 2006). The impact of long-range dust transport, with its multiple forcings and feedbacks, is a relatively new and complex area of research, where input from several disciplines is needed. So far, many of these effects have only been parameterized in models in very simple terms. For example, the representation of dust sources remains a major uncertainty in dust modeling and estimates of the global mass of airborne dust. This is a problem where Earth scientists could make an important contribution, by working with climate scientists to determine the type of environments in which easily erodible soil particles might have accumulated over time. Geologists could also help to identify the predominant mineralogical composition of dust sources, which is crucial for calculating the radiative and chemical effects of dust but is currently known for only a few regions. Understanding how climate and geological processes control source extent and characterizing the mineral content of airborne dust are two of the fascinating challenges in future dust research.

  17. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    ... April 11, 2004 (top panels) contrast strongly with the dust storm that swept across Iraq and Saudi Arabia on May 13, 2004 (bottom panels). ... Apr 11 and May 13, 2004 Images:  Dust Storm location:  Middle East thumbnail:  ...

  18. Validating MODIS above-cloud aerosol optical depth retrieved from "color ratio" algorithm using direct measurements made by NASA's airborne AATS and 4STAR sensors

    NASA Astrophysics Data System (ADS)

    Jethva, Hiren; Torres, Omar; Remer, Lorraine; Redemann, Jens; Livingston, John; Dunagan, Stephen; Shinozuka, Yohei; Kacenelenbogen, Meloe; Segal Rosenheimer, Michal; Spurr, Rob

    2016-10-01

    We present the validation analysis of above-cloud aerosol optical depth (ACAOD) retrieved from the "color ratio" method applied to MODIS cloudy-sky reflectance measurements using the limited direct measurements made by NASA's airborne Ames Airborne Tracking Sunphotometer (AATS) and Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) sensors. A thorough search of the airborne database collection revealed a total of five significant events in which an airborne sun photometer, coincident with the MODIS overpass, observed partially absorbing aerosols emitted from agricultural biomass burning, dust, and wildfires over a low-level cloud deck during SAFARI-2000, ACE-ASIA 2001, and SEAC4RS 2013 campaigns, respectively. The co-located satellite-airborne matchups revealed a good agreement (root-mean-square difference < 0.1), with most matchups falling within the estimated uncertainties associated the MODIS retrievals (about -10 to +50 %). The co-retrieved cloud optical depth was comparable to that of the MODIS operational cloud product for ACE-ASIA and SEAC4RS, however, higher by 30-50 % for the SAFARI-2000 case study. The reason for this discrepancy could be attributed to the distinct aerosol optical properties encountered during respective campaigns. A brief discussion on the sources of uncertainty in the satellite-based ACAOD retrieval and co-location procedure is presented. Field experiments dedicated to making direct measurements of aerosols above cloud are needed for the extensive validation of satellite-based retrievals.

  19. The Fate of Saharan Dust Across the Atlantic and Implications for a Central American Dust Barrier

    NASA Technical Reports Server (NTRS)

    Nowottnick, E.; Colarco, P.; da Silva, A.; Hlavka, D.; McGill, M.

    2011-01-01

    Saharan dust was observed over the Caribbean basin during the summer 2007 NASA Tropical Composition, Cloud, and Climate Coupling (TC4) field experiment. Airborne Cloud Physics Lidar (CPL) and satellite observations from MODIS suggest a barrier to dust transport across Central America into the eastern Pacific. We use the NASA GEOS-5 atmospheric transport model with online aerosol tracers to perform simulations of the TC4 time period in order to understand the nature of this barrier. Our simulations are driven by the Modem Era Retrospective-Analysis for Research and Applications (MERRA) meteorological analyses. We evaluate our baseline simulated dust distributions using MODIS and CALIOP satellite and ground-based AERONET sun photometer observations. GEOS-5 reproduces the observed location, magnitude, and timing of major dust events, but our baseline simulation does not develop as strong a barrier to dust transport across Central America as observations suggest. Analysis of the dust transport dynamics and lost processes suggest that while both mechanisms play a role in defining the dust transport barrier, loss processes by wet removal of dust are about twice as important as transport. Sensitivity analyses with our model showed that the dust barrier would not exist without convective scavenging over the Caribbean. The best agreement between our model and the observations was obtained when dust wet removal was parameterized to be more aggressive, treating the dust as we do hydrophilic aerosols.

  20. Dust Telescopes and Active Dust Collectors: Linking Dust to Their Sources

    NASA Astrophysics Data System (ADS)

    Drake, K. J.; Sternovsky, Z.; Gruen, E.; Srama, R.; Auer, S.; Horanyi, M.; Kempf, S.; Krueger, H.; Postberg, F.

    2010-12-01

    Cosmic dust particles from remote sites and times are treasures of information. By determining the dust particles' source and their elemental properties, we can learn about the environments, where they were formed and processed. Born as stardust in the cool atmospheres of giant stars or in novae and supernovae explosions, the particles are subsequently modified in the interstellar medium. Interplanetary dust that originates from comets and asteroids represents even more processed material at different stages of Solar System evolution. Interstellar and interplanetary dust particles from various sources can be detected and analyzed in the near-Earth space environment. The newly developed instruments Dust Telescope and Active Dust Collector are able to determine the origin of dust particles and provide their elemental composition. A Dust Telescope is a combination of a Dust Trajectory Sensor (DTS) [1] together with an analyzer for the chemical composition of dust particles in space. Dust particles' trajectories are determined by the measurement of induced electric signals when a charged grain flies through a position sensitive electrode system. A modern DTS can measure dust particles as small as 0.2 µm in radius and dust speeds up to 100 km/s. Large area chemical analyzers of 0.1 m2 sensitive area have been tested at a dust accelerator and it was demonstrated that they have sufficient mass resolution to resolve ions with atomic mass number up to >100 [2]. The advanced Dust Telescope is capable of identifying interstellar and interplanetary grains, and measuring their mass, velocity vector, charge, elemental and isotopic compositions. An Active Dust Collector combines a DTS with an aerogel or other dust collector materials, e.g. like the ones used on the Stardust mission. The combination of a DTS with a dust collector provides not only individual trajectories of the collected particles but also their impact time and position on the collector which proves essential to

  1. Particle atlas of World Trade Center dust

    USGS Publications Warehouse

    Lowers, Heather; Meeker, Gregory P.

    2005-01-01

    The United States Environmental Protection Agency (EPA) has begun a reassessment of the presence of World Trade Center (WTC) dust in residences, public buildings, and office spaces in New York City, New York. Background dust samples collected from residences, public buildings, and office spaces will be analyzed by multiple laboratories for the presence of WTC dust. Other laboratories are currently studying WTC dust for other purposes, such as health effects studies. To assist in inter-laboratory consistency for identification of WTC dust components, this particle atlas of phases in WTC dust has been compiled.

  2. Domestic airborne black carbon and exhaled nitric oxide in children in NYC.

    PubMed

    Cornell, Alexandra G; Chillrud, Steven N; Mellins, Robert B; Acosta, Luis M; Miller, Rachel L; Quinn, James W; Yan, Beizhan; Divjan, Adnan; Olmedo, Omar E; Lopez-Pintado, Sara; Kinney, Patrick L; Perera, Frederica P; Jacobson, Judith S; Goldstein, Inge F; Rundle, Andrew G; Perzanowski, Matthew S

    2012-01-01

    Differential exposure to combustion by-products and allergens may partially explain the marked disparity in asthma prevalence (3-18%) among New York City neighborhoods. Subclinical changes in airway inflammation can be measured by fractional exhaled nitric oxide (FeNO). FeNO could be used to test independent effects of these environmental exposures on airway inflammation. Seven- and eight-year-old children from neighborhoods with lower (range 3-9%, n=119) and higher (range 11-18%, n=121) asthma prevalence participated in an asthma case-control study. During home visits, FeNO was measured, and samples of bed dust (allergens) and air (black carbon; BC) were collected. Neighborhood built-environment characteristics were assessed for the 500 m surrounding participants' homes. Airborne BC concentrations in homes correlated with neighborhood asthma prevalence (P<0.001) and neighborhood densities of truck routes (P<0.001) and buildings burning residual oil (P<0.001). FeNO concentrations were higher among asthmatics with than in those without frequent wheeze (≥4 times/year) (P=0.002). FeNO concentrations correlated with domestic BC among children without seroatopy (P=0.012) and with dust mite allergen among children with seroatopy (P=0.020). The association between airborne BC in homes and both neighborhood asthma prevalence and FeNO suggest that further public health interventions on truck emissions standards and residual oil use are warranted. PMID:22377682

  3. The effect of dust lifting process on the electrical properties of the atmosphere

    NASA Astrophysics Data System (ADS)

    Esposito, Francesca; Molinaro, Roberto; Ionut Popa, Ciprian; Molfese, Cesare; Cozzolino, Fabio; Marty, Laurent; Taj-Eddine, Kamal; Di Achille, Gaetano; Silvestro, Simone; Ori, Gian Gabriele

    2015-04-01

    Airborne dust and aerosol particles affect climate by absorbing and scattering thermal and solar radiation and acting as condensation nuclei for the formation of clouds. So, they strongly influence the atmospheric thermal structure, balance and circulation. On Earth and Mars, this 'climate forcing' is one of the most uncertain processes in climate change predictions. Wind-driven blowing of sand and dust is also responsible for shaping planetary surfaces through the formation of sand dunes and ripples, the erosion of rocks, and the creation and transport of soil particles. These processes are not confined to Earth, but occur also on Mars, Venus and Titan. It is clear that the knowledge of the atmospheric dust properties and the mechanisms of dust settling and raising into the atmosphere are important to understand planetary climate and surface evolution. On Mars the physical processes responsible for dust injection into the atmosphere are still poorly understood, but they likely involve saltation as on Earth. Saltation is a process where large sand grains are forced by the wind to move in ballistic trajectories on the soil surface. During these hops they hit dust particles, that are well bound to the soil due to interparticle cohesive forces, thus transferring to them the momentum necessary to be entrained into the atmosphere. Recently, it has been shown that this process is also responsible to generate strong electric fields in the atmosphere up to 100-150 kV/m. This enhanced electric force acts as a feedback in the dust lifting process, lowering the threshold of the wind friction velocity u* necessary to initiate sand saltation. It is an important aspect of dust lifting process that need to be well characterized and modeled. Even if literature reports several measurements of E-fields in dust devils events, very few reports deal with atmospheric electric properties during dust storms or isolated gusts. We present here preliminary results of an intense field test

  4. The variation of characteristics and formation mechanisms of aerosols in dust, haze, and clear days in Beijing

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Zhuang, Guoshun; Sun, Yele; An, Zhisheng

    A 4-year campaign from 2001 to 2004 monitoring PM 2.5 and TSP in the spring season in urban Beijing, China was performed to study the variation of characteristics and the different formation mechanisms of aerosols in dust, haze, and clear days. A total of 315 aerosol samples were collected and used in this study. The aerosols were more basic in dust days and more acidic in haze days. The ions presented in the order of SO42->Ca 2+≫ NO3->Cl -> NH4+>Na + in dust days, and of SO42-> NO3-> NH4+≫Cl ->Ca 2+>K + in haze days. Ions has been classified into three groups, "Na +, Mg 2+, Ca 2+", "K +, SO42-, Cl -", and " NO3-, NH4+", representing crust, pollution-crust, and pollution species, respectively. Crust and pollution ions were the main ion fractions in dust and haze days, respectively. The variation of Ca 2+/Al showed that the increase of dust in dust and haze days was from soil and construction, respectively. "CaCO 3, CaSO 4, and (NH 4) 2SO 4" and "(NH 4) 2SO 4, NH 4NO 3, and Ca(NO 3) 2" were the major species in dust and haze days, respectively. The formation of CaSO 4 on airborne soil particles and the formation of (NH 4) 2SO 4 and NH 4NO 3 were the predominant pathways of sulfate and nitrate formations in dust and haze days, respectively. Sulfate might be mainly formed through heterogeneous reactions in the aqueous surface layer on the pre-existing particles, while nitrate mainly through homogeneous gas-phase reactions in the spring season in Beijing. The formation of sulfate and nitrate was accelerated in dust and haze days.

  5. Collecting apparatus

    DOEpatents

    Duncan, Charles P.

    1983-01-01

    An improved collecting apparatus for small aquatic or airborne organisms such as plankton, larval fish, insects, etc. The improvement constitutes an apertured removal container within which is retained a collecting bag, and which is secured at the apex of a conical collecting net. Such collectors are towed behind a vessel or vehicle with the open end of the conical net facing forward for trapping the aquatic or airborne organisms within the collecting bag, while allowing the water or air to pass through the apertures in the container. The container is readily removable from the collecting net whereby the collecting bag can be quickly removed and replaced for further sample collection. The collecting bag is provided with means for preventing the bag from being pulled into the container by the water or air flowing therethrough.

  6. [Occupational exposure to airborne fungi and bacteria in a household recycled container sorting plant ].

    PubMed

    Solans, Xavier; Alonso, Rosa María; Constans, Angelina; Mansilla, Alfonso

    2007-06-01

    Several studies have showed an association between the work in waste treatment plants and occupational health problems such as irritation of skin, eyes and mucous membranes, pulmonary diseases, gastrointestinal problems and symptoms of organic dust toxic syndrome (ODTS). These symptoms have been related to bioaerosol exposure. The aim of this study was to investigate the occupational exposure to biological agents in a plant sorting source-separated packages (plastics materials, ferric and non-ferric metals) household waste. Airborne samples were collected with M Air T Millipore sampler. The concentration of total fungi and bacteria and gram-negative bacteria were determined and the most abundant genera were identified. The results shown that the predominant airborne microorganisms were fungi, with counts greater than 12,000 cfu/m(3) and gram-negative bacteria, with a environmental concentration between 1,395 and 5,280 cfu/m(3). In both cases, these concentrations were higher than levels obtained outside of the sorting plant. Among the fungi, the predominant genera were Penicillium and Cladosporium, whereas the predominant genera of gram-negative bacteria were Escherichia, Enterobacter, Klebsiella and Serratia. The present study shows that the workers at sorting source-separated packages (plastics materials, ferric and non-ferric metals) domestic waste plant may be exposed to airborne biological agents, especially fungi and gram-negative bacteria.

  7. [Occupational exposure to airborne fungi and bacteria in a household recycled container sorting plant ].

    PubMed

    Solans, Xavier; Alonso, Rosa María; Constans, Angelina; Mansilla, Alfonso

    2007-06-01

    Several studies have showed an association between the work in waste treatment plants and occupational health problems such as irritation of skin, eyes and mucous membranes, pulmonary diseases, gastrointestinal problems and symptoms of organic dust toxic syndrome (ODTS). These symptoms have been related to bioaerosol exposure. The aim of this study was to investigate the occupational exposure to biological agents in a plant sorting source-separated packages (plastics materials, ferric and non-ferric metals) household waste. Airborne samples were collected with M Air T Millipore sampler. The concentration of total fungi and bacteria and gram-negative bacteria were determined and the most abundant genera were identified. The results shown that the predominant airborne microorganisms were fungi, with counts greater than 12,000 cfu/m(3) and gram-negative bacteria, with a environmental concentration between 1,395 and 5,280 cfu/m(3). In both cases, these concentrations were higher than levels obtained outside of the sorting plant. Among the fungi, the predominant genera were Penicillium and Cladosporium, whereas the predominant genera of gram-negative bacteria were Escherichia, Enterobacter, Klebsiella and Serratia. The present study shows that the workers at sorting source-separated packages (plastics materials, ferric and non-ferric metals) domestic waste plant may be exposed to airborne biological agents, especially fungi and gram-negative bacteria. PMID:17604432

  8. Occupational exposure to airborne asbestos from phenolic molding material (Bakelite) during sanding, drilling, and related activities.

    PubMed

    Mowat, Fionna; Bono, Michael; Lee, R J; Tamburello, Susan; Paustenbach, Dennis

    2005-10-01

    In this study, a historical phenolic (Bakelite) molding material, BMMA-5353, was tested to determine the airborne concentrations of asbestos fibers released during four different activities (sawing, sanding, drilling, and cleanup of dust generated from these activities). Each activity was performed for 30 min, often in triplicate. The primary objective for testing BMMA-5353 was to quantitatively determine the airborne concentration of asbestos fibers, if any, in the breathing zone of workers. Uses of this product typically did not include sawing or sanding, but it may have been drilled occasionally. For this reason, only small quantities were sawed, sanded, and drilled in this simulation study. Personal (n = 40), area (n = 80), and background/clearance (n = 88) air samples were collected during each activity and analyzed for total fiber concentrations using phase contrast microscopy (PCM) and, for asbestos fiber counts, transmission electron microscopy (TEM). The raw PCM-total fiber concentrations were adjusted based on TEM analyses that reported the fraction of asbestos fibers, to derive a PCM-asbestos concentration that would enable calculation of an 8-hour time-weighted average (TWA). The estimated 8-hour TWAs ranged from 0.006 to 0.08 fibers per cubic centimeter using a variety of worker exposure scenarios. Therefore, assuming an exposure scenario in which a worker uses power tools to cut and sand products molded from BMMA-5353 and similar products in the manner evaluated in this study, airborne asbestos concentrations should not exceed current or historical occupational exposure limits.

  9. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

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

  10. Understanding mineral dusts from the Middle East

    NASA Astrophysics Data System (ADS)

    Engelbrecht, J. P.; McDonald, E.; Gillies, J. A.; Jayanty, J.; Casuccio, G.; Gertler, A.

    2012-12-01

    The purpose of the program was to provide scientifically founded information on the chemical and physical properties of airborne mineral dust collected during a period of approximately one year, largely in 2006, at Djibouti, Afghanistan (Bagram, Khowst), Qatar, United Arab Emirates, Iraq (Balad, Baghdad, Tallil, Tikrit, Taji, Al Asad), and Kuwait (Northern, Central, Coastal, and Southern regions). To fully understand mineral dusts, their chemical and physical properties as well as mineralogical interrelationships were accurately established. Three collocated low volume particulate samplers, one each for the total suspended (TSP), less than 10 μm in aerodynamic diameter (PM10), and less than 2.5 μm in aerodynamic diameter (PM2.5) particulate matter were deployed at each of the 15 sites, operating on a "1 in 6 day" sampling schedule. A total of 3,136 filter samples were collected on a 1-in-6 day schedule, along with one-time bulk soil samples, at each of the 15 sites. Sample media included Teflon® membrane and quartz fiber filters for chemical analysis (71 species), and Nuclepore® filters for individual particle analysis by Scanning Electron Microscopy (SEM). The provisional study of the data revealed three broad air pollution sources: geological dust, smoke from burn pits, and until now unidentified lead-zinc smelters and battery-processing facilities. SEM results and secondary electron imagery show that quartz and other silicate minerals and, to a lesser extent, dolomite and calcite particles are coated by a thin Si-Al-Mg layer, probably the clay minerals palygorskite and/or montmorillonite/illite. Positive Matrix Factorization (PMF) was performed on aerosol samples collected at six military sites in Iraq (Balad, Baghdad, Tallil, Tikrit, Taji, and Al Asad). PMF results reflect chemical differences amongst sources impacting at individual sites, further complicated by the regional geomorphology and meteorology. Sampling sites are seldom impacted by one source at

  11. Sahara Dust

    Atmospheric Science Data Center

    2013-04-15

    article title:  Casting Light and Shadows on a Saharan Dust Storm   ... CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, ...

  12. Impact of Middle Eastern dust storms on indoor and outdoor composition of bioaerosol

    NASA Astrophysics Data System (ADS)

    Soleimani, Zahra; Goudarzi, Gholamreza; Sorooshian, Armin; Marzouni, Mohammad Bagherian; Maleki, Heidar

    2016-08-01

    The presence of microbes in airborne aerosol particles, especially dust, is a major public health concern in desert regions. This study is the first of its kind to examine the effect of dust storms on indoor and outdoor microbial air quality at a hospital on the western side of Iran (city of Ahvaz), which is notorious for being highly vulnerable to dust emissions. Air samples were collected inside and outside of the hospital environment for six months, with the unique advantage of this study being that the region and duration of measurements allow for a clear comparison between dusty and normal days. On normal days, the average concentrations (outdoor/indoor) of bacteria and fungi were 423/329 cfu m-3 and 596/386 cfu m-3, respectively, which increased to 1257/406 cfu m-3 and 1116/550 cfu m-3 on dust event days. Indoor/Outdoor ratios for bacteria and fungi are lower on dust event days (0.26-0.60) versus normal days (0.44-0.95). Bacillus spp., Micrococcus spp., Streptomyces spp., and Staphylococcus spp. were the dominant bacteria both indoors and outdoors on normal and dust event days. Gram positive bacteria exhibited higher concentrations than Gram negative bacteria in both outdoor and indoor air samples as well as during both normal and dust event days. The data suggest that Gram positive bacteria are more resistant to undesirable outdoor conditions (e.g., high incident solar radiation) as compared to Gram negative ones. These results have implications for other populated arid regions where more stringent control of indoor air quality can greatly benefit public health.

  13. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  14. NASA Student Airborne Research Program

    NASA Astrophysics Data System (ADS)

    Schaller, E. L.; Shetter, R. E.

    2012-12-01

    The NASA Student Airborne Research Program (SARP) is a unique summer internship program for advanced undergraduates and early graduate students majoring in the STEM disciplines. SARP participants acquire hands-on research experience in all aspects of an airborne research campaign, including flying onboard an major NASA resource used for studying Earth system processes. In summer 2012, thirty-two participants worked in four interdisciplinary teams to study surface, atmospheric, and oceanographic processes. Participants assisted in the operation of instruments onboard the NASA P-3B aircraft where they sampled and measured atmospheric gases and imaged land and water surfaces in multiple spectral bands. Along with airborne data collection, students participated in taking measurements at field sites. Mission faculty and research mentors helped to guide participants through instrument operation, sample analysis, and data reduction. Over the eight-week program, each student developed an individual research project from the data collected and delivered a conference-style final presentation on his/her results. We will discuss the results and effectiveness of the program from the first four summers and discuss plans for the future.

  15. Interstellar and Cometary Dust

    NASA Technical Reports Server (NTRS)

    Mathis, John S.

    1997-01-01

    /carbonaceous matrix, without organic refractory mantles, in between the ices. Unfortunately, they may be significantly processed by chemical processes accompanying the warming (over the 10 K of the dark cloud cores) which occurs in the outer solar system. Evidence of this processing is the chemical anomalies present in interplanetary dust particles collected in the stratosphere, which may be the most primitive materials we have obtained to date. The comet return mission would greatly clarify the situation, and probably provide samples of genuine interstellar grains.

  16. Interstellar and Cometary Dust

    NASA Astrophysics Data System (ADS)

    Mathis, John S.

    1997-12-01

    /carbonaceous matrix, without organic refractory mantles, in between the ices. Unfortunately, they may be significantly processed by chemical processes accompanying the warming (over the 10 K of the dark cloud cores) which occurs in the outer solar system. Evidence of this processing is the chemical anomalies present in interplanetary dust particles collected in the stratosphere, which may be the most primitive materials we have obtained to date. The comet return mission would greatly clarify the situation, and probably provide samples of genuine interstellar grains.

  17. Collection and analysis of samples for polycyclic aromatic hydrocarbons in dust and other solids related to sealed and unsealed pavement from 10 cities across the United States, 2005-07

    USGS Publications Warehouse

    Van Metre, Peter C.; Mahler, Barbara J.; Wilson, Jennifer T.; Burbank, Teresa L.

    2008-01-01

    Parking lots and driveways are dominant features of the modern urban landscape, and in the United States, sealcoat is widely used on these surfaces. One of the most widely used types of sealcoat contains refined coal tar; coal-tar-based sealcoat products have a mean polycyclic aromatic hydrocarbon (PAH) concentration of about 5 percent. A previous study reported that parking lots in Austin, Texas, treated with coal-tar sealcoat were a major source of PAH compounds in streams. This report presents methods for and data from the analysis of concentrations of PAH compounds in dust from sealed and unsealed pavement from nine U.S. cities, and concentrations of PAH compounds in other related solid materials (sealcoat surface scrapings, nearby street dust, and nearby soil) from three of those same cities and a 10th city. Dust samples were collected by sweeping dust from areas of several square meters with a soft nylon brush into a dustpan. Some samples were from individual lots or driveways, and some samples consisted of approximately equal amounts of material from three lots. Samples were sieved to remove coarse sand and gravel and analyzed by gas chromatography/mass spectrometry. Concentrations of PAHs vary greatly among samples with total PAH (sigmaPAH), the sum of 12 unsubstituted parent PAHs, ranging from nondetection for all 12 PAHs (several samples from Portland, Oregon, and Seattle, Washington; sigmaPAH of less than 36,000 micrograms per kilogram) to 19,000,000 micrograms per kilogram for a sealcoat scraping sample (Milwaukee, Wisconsin). The largest PAH concentrations in dust are from a driveway sample from suburban Chicago, Illinois (sigmaPAH of 9,600,000 micrograms per kilogram).

  18. Global potential of dust devil occurrence

    NASA Astrophysics Data System (ADS)

    Jemmett-Smith, Bradley; Marsham, John; Knippertz, Peter; Gilkeson, Carl

    2014-05-01

    Mineral dust is a key constituent in the climate system. Airborne mineral dust forms the largest component of the global aerosol budget by mass and subsequently affects climate, weather and biogeochemical processes. There remains large uncertainty in the quantitative estimates of the dust cycle. Dry boundary-layer convection serves as an effective mechanism for dust uplift, typically through a combination of rotating dust devils and non-rotating larger and longer-lived convective plumes. These microscale dry-convective processes occur over length scales of several hundred metres or less. They are difficult to observe and model, and therefore their contribution to the global dust budget is highly uncertain. Using an analytical approach to extrapolate limited observations, Koch and Renno (2006) suggest that dust devils and plumes could contribute as much as 35%. Here, we use a new method for quantifying the potential of dust devil occurrence to provide an alternative perspective on this estimate. Observations have shown that dust devil and convective plume occurrence is favoured in hot arid regions under relatively weak background winds, large ground-to-air temperature gradients and deep dry convection. By applying such known constraints to operational analyses from the European Centre for Medium Range Weather Forecasts (ECMWF), we provide, to the best of the authors' knowledge, the first hourly estimates of dust devil occurrence including an analysis of sensitivity to chosen threshold uplift. The results show the expected diurnal variation and allow an examination of the seasonal cycle and day-to-day variations in the conditions required for dust devil formation. They confirm that desert regions are expected to have by far the highest frequency of dry convective vortices, with winds capable of dust uplift. This approach is used to test the findings of Koch and Renno (2006). Koch J., Renno N. (2006). The role of convective plumes and vortices on the global aerosol

  19. Analysis of the particles transported with dust-clouds reaching Cordoba, southwestern Spain.

    PubMed

    Cariñanos, Paloma; Galán, Carmen; Alcázar, Purificación; Domínguez, Eugenio

    2004-02-01

    Dust-cloud episodes were detected in summer 1999 in the city of Cordoba, southwestern Spain, with a higher frequency than usual. Solid airborne particles were collected using a suction volumetric sampler and analyzed to determine both their nature and their origin. Nonbiological material was mostly identified as mineral sand and partially burned remains of hydrocarbons and stubble. Amounts were estimated in terms of the percentage of microscopic field of view covered. Biological materials, in this case pollen grains, were identified and classified as belonging to either autochthonous or remote flora; in the latter case, the possibility was examined that they might originate in North Africa. Some pollen types were also used as tracers to chart the path followed by the sand clouds within the Iberian Peninsula. Meteorological conditions on the days in which episodes occurred were analyzed. In all cases, very dry southwesterly winds were recorded, at moderate to high speeds, together with temperatures of over 35 degrees C. The increase in airborne pollen detected, together with the large amount of particles collected, could have an adverse effect on health, particularly in pollen allergy sufferers, for whom dust-clouds represent an added risk.

  20. The Dynamics and Characteristics of Aeolian Dust in Dryland Central Asia: Possible Impacts on Respiratory Health in the Aral Sea Basin

    NASA Astrophysics Data System (ADS)

    Wiggs, G. F.; O'Hara, S.; Wegerdt, J.; van der Meer, J.; Small, I.; Hubbard, R.

    2003-12-01

    Over the last 40 years over 36,000 km2 of the former Aral Sea bed have been exposed creating a potentially significant aeolian dust source. It is widely believed, but little researched, that increased dust storm activity in the region has had a major impact on human health. In this paper we report the findings of a study into the link between dust exposure and respiratory health amongst children in the Autonomous Republic of Karakalpakstan, located on the southern shore of the Aral Sea. Data were collected over a 12 month period at 16 sites located within a broad transect running north to south through Karakalpakstan. At each site monthly measurements of dust deposition were undertaken linked with daily meteorological data at 6 stations. At 3 sites weekly measurements of PM10 were also carried out. Approximately 100 children (aged 7-10 years) were randomly selected within 5 km of each dust trap site and data were collected on their respiratory health and environmental exposures. Lung function data were also collected using a handheld spirometer. A linear regression model was used to predict lung function for the children incorporating variables for Forced Expiratory Volume in one second (FEV1), age, gender, height and weight and we estimated the impact of dust deposition rates on the odds of having abnormal lung function using logistic regression. The findings indicate that dust deposition rates across the region are high with sites located near the former shore of the sea being the worst affected. For these northerly regions the former Aral Sea bed is the most likely source of dust. The situation for the rest of the country seems to be far more complex. In these regions it appears that local sources (agricultural fields, abandoned irrigation grounds, overgrazed dunes, and unpaved roads) and more distant sources to the south and south-west represent significant sediment providers, particularly in the early summer when agricultural fields are ploughed. We found some

  1. Existence state of bromine as an indicator of the source of brominated flame retardants in indoor dust.

    PubMed

    Suzuki, Go; Kida, Akiko; Sakai, Shin-ichi; Takigami, Hidetaka

    2009-03-01

    Indoor dust is an important medium for human exposure to brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). In this study, we used micro X-ray fluorescence spectrometry (XRFS), digital optical microscopy, and gas chromatography-high resolution mass spectrometry to investigate the existence state of bromine as an indicator of the source of BFRs in indoor dusts and in dusts from the interior of televisions collected in Japan. By means of micro XRFS bromine mapping conducted at a 0.5-s dwell time, we were able to detect bromine levels as low as about 0.1% at each point of about a beam diameter of 50 microm across. The presence of fragments containing 1.0% or more bromine was confirmed in 27 of the 48 dust samples tested. Using magnified images of the fragments, we classified them roughly into particulates and fibrous substances. We analyzed PBDEs in the fragments containing high concentrations of bromine (> or = 0.1%) and confirmed that the fragments contained PBDEs, mainly BDE 209. Furthermore, to detect bromine concentrations < or = 0.1% in the dust samples, we analyzed the samples at a dwell time of 100 s to enhance the detection sensitivity of mapping; atthis dwell time, we confirmed the presence of bromine in the dust coating. Our results suggest that bromine is transferred from products to dust matrixes not only through miniaturization and subsequent direct migration into dust as plastic and textile fragments but also through other pathways such as vaporization and airborne transfer of microparticulates. PMID:19350916

  2. Characterisation of allergens and airborne fungi in low and middle-income homes of primary school children in Durban, South Africa

    PubMed Central

    Jafta, Nkosana; Batterman, Stuart A.; Gqaleni, Nceba; Naidoo, Rajen N.; Robins, Thomas G.

    2012-01-01

    The South Durban Health Study is a population-based study that examined the relationship between exposure to ambient air pollutants and respiratory disease among school children with high prevalence of asthma who resided in two purposely-selected communities in north and south Durban, KwaZulu-Natal, South Africa. From these participants, a subgroup of 135 families was selected for investigation of household characteristics potentially related to respiratory health. In these households, a walkthrough investigation was conducted, and settled dust and air samples were collected for allergen and fungal measurements using standardised techniques. Asp f1 allergen was detected in all homes, and Bla g1 allergen was detected in half of the homes. House dust allergens, Der f1 and Der p1 exceeded concentrations associated with risk of sensitization and exacerbation of asthma in 3 and 13%, respectively, of the sampled homes, while Bla g1 exceeded guidance values in 13% of the homes. Although airborne fungal concentrations in sleep areas and indoors were lower than outdoor concentrations, they exceeded 1000 CFU/m3 in 29% of the homes. Multivariate analyses identified several home characteristics that were predictors of airborne fungal concentrations, including moisture, ventilation, floor type and bedding type. Airborne fungal concentrations were similar indoors and outdoors, which likely reduced the significance of housing and indoor factors as determinants of indoor concentrations. Conclusion Allergen concentrations were highly variable in homes, and a portion of the variability can be attributed to easily-recognised conditions. PMID:22674665

  3. A comparison between different high volume sampling systems for collecting ambient airborne particles for mutagenicity testing and for analysis of organic compounds.

    PubMed

    Alfheim, I; Lindskog, A

    1984-03-15

    Samples of urban air were collected simultaneously using different sampling systems, including electrostatic precipitation (ESP) and high volume filtration (HVF) on various filters for particle sampling and absorption on activated carbon and organic polymers for sampling of volatiles. Acetone extracts of the samples were analyzed for polycyclic aromatic hydrocarbons (PAH) and tested for mutagenicity with the Ames Salmonella/microsome assay. The results show that the concentrations of PAH found in the various particle-samples were in good agreement, whereas the mutagenic activity of these samples showed large variations. The highest mutagenic activity was found in the samples collected by ESP and on the teflon-coated glassfibre filters, whereas samples collected by high volume filtration with size-fractionation showed the lowest mutagenic activity. We do not know whether the higher activity in samples from the teflon-coated filters compared to those from ordinary glassfibre filters represent filter artifacts or if it represents a more pronounced degradation of mutagenic compounds on the non-coated glassfibre filters. Extracts from filter blanks seemed to interfere with the expression of the mutagenic activity of the positive controls, benzo[a]pyrene and nitropyrene. When sampling volatile compounds, two organic polymers, polyurethane (PUR) and XAD-2, were found suitable for collecting PAH, whereas no PAH could be detected in extracts from the activated carbon. The XAD-2 adsorbent was the most effective for sampling bicyclic PAH. None of the adsorbents yielded extracts well suited for mutagenicity testing, since blank extracts were toxic to the test bacteria. Some extracts of the PUR blanks were weakly mutagenic as well. More emphasis should be placed upon developing more efficient and unreactive adsorbents and on the adaptation of such adsorbents in samplers suited for routine use. PMID:6719098

  4. Flying Through Dust From Asteroids

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-11-01

    How can we tell what an asteroid is made of? Until now, weve relied on remote spectral observations, though NASAs recently launched OSIRIS-REx mission may soon change this by landing on an asteroid and returning with a sample.But what if we could learn more about the asteroids near Earth without needing to land on each one? It turns out that we can by flying through their dust.The aerogel dust collector of the Stardust mission. [NASA/JPL/Caltech]Ejected CluesWhen an airless body is impacted by the meteoroids prevalent throughout our solar system, ejecta from the body are flung into the space around it. In the case of small objects like asteroids, their gravitational pull is so weak that most of the ejected material escapes, forming a surrounding cloud of dust.By flying a spacecraft through this cloud, we could perform chemical analysis of the dust, thereby determining the asteroids composition. We could even capture some of the dust during a flyby (for example, by using an aerogel collector like in the Stardust mission) and bring it back home to analyze.So whats the best place to fly a dust-analyzing or -collecting spacecraft? To answer this, we need to know what the typical distribution of dust is around a near-Earth asteroid (NEA) a problem that scientists Jamey Szalay (Southwest Research Institute) and Mihly Hornyi (University of Colorado Boulder) address in a recent study.The colors show the density distribution for dust grains larger than 0.3 m around a body with a 10-km radius. The distribution is asymmetric, with higher densities on the apex side, shown here in the +y direction. [Szalay Hornyi 2016]Moon as a LaboratoryTo determine typical dust distributions around NEAs, Szalay and Hornyi first look at the distribution of dust around our own Moon, caused by the same barrage of meteorites wed expect to impact NEAs. The Moons dust cloud was measured in situ in 2013 and 2014 by the Lunar Dust Experiment (LDEX) on board the Lunar Atmosphere and Dust Environment

  5. Assessment of Occupational Exposure to Dust and Crystalline Silica in Foundries

    PubMed Central

    Omidianidost, Ali; Azari, Mansour R.; Golbabaei, Farideh

    2015-01-01

    Background: The term “crystalline silica” refers to crystallized form of SiO2 and quartz, as the most abundant compound on the earth’s crust; it is capable of causing silicosis and lung cancer upon inhaling large doses in the course of occupational exposure. The aim of this study was to assess occupational exposure to dust and crystalline silica in foundries in Pakdasht, Iran. Materials and Methods: In this study, airborne dust samples were collected on PVC filters (37 mm diameter, 0.8 mm pore size), by using a sampling pump and open face cyclone at a flow rate of 2.2 l/min for a maximum volume of 800 liters. For determining crystalline silica spectrometry was used according to the National Institute of Occupational Safety and Health (NIOSH) method No. 7601 for analysis of samples. Results: Results showed that crystalline silica concentration was higher than NIOSH and the American Conference of Government Industrial Hygienist (ACGIH) allowed extent (0.025 mg/m3). Concentration of crystalline silica was 0.02–0.1 mg/m3. Total dust concentration average was higher than the allowed extent by Permissible Exposure Limit (PEL) of the Occupational Safety and Health Administration (OSHA). Conclusion: It is essential to take necessary measures to control crystalline silica dust regarding the fact that 50% of workers are exposed to higher than the allowed extent. PMID:26858767

  6. The distribution of dust mite allergen in the houses of patients with asthma

    SciTech Connect

    Tovey, E.R.; Chapman, M.D.; Wells, C.W.; Platts-Mills, T.A.

    1981-11-01

    Using an inhibition radioimmunoassay for the major allergen from Dermatophagoides pteronyssinus (antigen P1), we studied the distribution of this dust allergen in the houses of patients with asthma. Both bed and floor dust samples contained a wide range of antigen P1, 100 to 100,000 ng/g of fine dust, and this concentration correlated well with the number of mite bodies (r . 0.81, p less than 0.001). We were unable to detect antigen P1 in the air of undisturbed rooms. However, during domestic activity, between 1 and 30 ng were collected on a filter than sampled air for 45 min at 17 L/min. Using a cascade impactor it was shown that greater than 80% of the airborne antigen P1 was associated with particles greater than 10 mu in diameter. Some of the particles containing allergen could be identified because they formed precipitin rings when impacted onto agarose containing rabbit antimite antiserum. These particles had the physical appearance of mite feces, which are the major source of antigen P1 in mite cultures. The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allergen.

  7. Determination of zinc speciation in basic oxygen furnace flying dust by chemical extractions and X-ray spectroscopy.

    PubMed

    Sammut, M L; Rose, J; Masion, A; Fiani, E; Depoux, M; Ziebel, A; Hazemann, J L; Proux, O; Borschneck, D; Noack, Y

    2008-02-01

    There is a growing concern regarding the environmental and public health risks associated with airborne particulate matter (PM). The basic oxygen furnace is one of the most important atmospheric dust sources of the steel manufacturing process. It emits dust enriched in heavy metal such as Zn, which is assumed to contribute to the toxic potential of atmospheric PM. Dust collected before and after the filtration system was analyzed to determine Zn speciation. To this end, a variety of analytical tools were used and a sequential extraction protocol has been specifically developed for iron and steel dust. The Zn speciation results obtained by EXAFS and sequential extraction were in excellent agreement. Before filtration, the speciation of Zn in BOF was 43% ZnFe(2)O(4), 23% ZnCO(3) and 16% ZnO. The same species were detected after filtration with different proportions. BOF dust after filtration contains more soluble Zn phases which may play a role in the toxic effects of the emissions.

  8. Evaluation of laser-induced breakdown spectroscopy (LIBS) for measurement of silica on filter samples of coal dust.

    PubMed

    Stipe, Christopher B; Miller, Arthur L; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

    2012-11-01

    Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 μg/cm(2) and 0.05 μg/cm(2), respectively (corresponding to 0.16 μg/cm(2) and 0.20 μg/cm(2) for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring. PMID:23146184

  9. Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) for Measurement of Silica on Filter Samples of Coal Dust

    PubMed Central

    Stipe, Christopher B.; Miller, Arthur L.; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

    2015-01-01

    Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 µg/cm2 and 0.05 µg/cm2, respectively (corresponding to 0.16 µg/cm2 and 0.20 µg/cm2 for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring. PMID:23146184

  10. Estimation of the contributions of brake dust, tire wear, and resuspension to nonexhaust traffic particles derived from atmospheric measurements.

    PubMed

    Harrison, Roy M; Jones, Alan M; Gietl, Johanna; Yin, Jianxin; Green, David C

    2012-06-19

    Size-fractionated samples of airborne particulate matter have been collected in a number of campaigns at Marylebone Road, London and simultaneously at background sites either in Regents Park or at North Kensington. Analysis of these samples has enabled size distributions of total mass and of a number of elements to be determined, and roadside increments attributable to nonexhaust emissions arising from traffic activity have been calculated. Taking a novel approach, the combined use of size distribution information and tracer elements has allowed the separate estimation of the contributions of brake dust, tire dust, and resuspension to particle mass in the range 0.9-11.5 μm aerodynamic diameter and mean contributions (± s.e.) at the Marylebone Road sampling site are estimated as resuspended dust 38.1 ± 9.7%, brake dust 55.3 ± 7.0%, and tire dust 10.7 ± 2.3%, (accounting for a total of 104.1% of coarse particle mass in the traffic increment above background).

  11. Infrared spectral challenges of individual, respirable, micron-sized dust particles: Strong phonons and their distorted lineshapes

    NASA Astrophysics Data System (ADS)

    Coe, James

    2015-03-01

    Consideration of cluster properties as they grow through the nanosize regime and into the micron-sized regime, leads to expectations of bulk-like trends which are well understood. However, individual micron-sized particles are of comparable size to the wavelength of probing infrared (IR) light, so vibrational spectra will be dominated by scattering effects and lineshapes will have dispersion and saturation distortions. Airborne dust particles of ~ 4 micron widths are of particular health interest because they get past the nose, throat, and thorax and can be inhaled into people's lungs. This talk will describe the use of plasmonic metal mesh to obtain scatter-free, IR absorption spectra of single, ~ 4 micron respirable particles. A dust library of single particle IR spectra is being compiled to chemically characterize respirable dust and a Mie-Bruggeman model has been created to predict the IR spectra of collections of mixed-composition dust particles. Having dealt with scattering effects, the remaining difficulty involves the effect of strong phonons. Many of the most common mineral components of dust have strong phonons with intensity cross sections comparable to the size of the particle which leads to severe and interesting lineshape distortions. NSF CHE 1213293.

  12. Concentrations, enrichment and predominant sources of Sb and other trace elements in size classified airborne particulate matter collected in Tokyo from 1995 to 2004.

    PubMed

    Furuta, Naoki; Iijima, Akihiro; Kambe, Akiko; Sakai, Kazuhiro; Sato, Keiichi

    2005-12-01

    APM was collected and trace elements existing in the particles were monitored since May 1995 in this study. APM sample was collected separately by size (d < 2 microm, 2-11 microm and >11 microm) on the roof of the university building (45 m above ground) in the campus of Faculty of Science and Engineering, Chuo University, Tokyo, Japan, using an Anderson low volume air sampler. The collected sample was digested by HNO3, H2O2 and HF using a microwave oven, and major elements (Na, Mg, Al, K, Ca and Fe) were measured by ICP-AES, and trace elements (Li, Be, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb) were measured by ICP-MS. It was observed that the APM concentration was higher between the winter and the spring, compared to during the summer. The enrichment factor was calculated for each element in each set of APM (d < 2 microm, 2-11 microm and >11 microm). Seasonal trends of enrichment factors were examined, and the elements were classified into 3 groups according to the common seasonal behavior. It is likely that the elements in the same group have common origins. Toxic pollutant elements (Sb, Se, Cd, Pb and As) were found in small particles with d of <2 microm in concentrated levels. Antimony (Sb) had the highest enrichment factor, and the results suggested that Sb level in APM was extremely high. The origins of Sb were sought, and wastes from plastic incineration and brake pad wears of automobiles were suspected. Each set of APM (d < 2 microm, 2-11 microm and >11 microm) was classified by the shape, and the shape-dependent constituents of a single APM particle were quantitatively measured by SEM-EDX. High concentration of Sb was found in APM <2 microm and square particles. Particles less than 2 microm and square shaped particles were major particles produced by actual car braking experiments. From these experimental results it was concluded that the source of Sb in squared APM <2 microm is considered to be from brake pad wear. PMID:16307066

  13. Laser Doppler dust devil measurements

    NASA Technical Reports Server (NTRS)

    Bilbro, J. W.; Jeffreys, H. B.; Kaufman, J. W.; Weaver, E. A.

    1977-01-01

    A scanning laser doppler velocimeter (SLDV) system was used to detect, track, and measure the velocity flow field of naturally occurring tornado-like flows (dust devils) in the atmosphere. A general description of the dust devil phenomenon is given along with a description of the test program, measurement system, and data processing techniques used to collect information on the dust devil flow field. The general meteorological conditions occurring during the test program are also described, and the information collected on two selected dust devils are discussed in detail to show the type of information which can be obtained with a SLDV system. The results from these measurements agree well with those of other investigators and illustrate the potential for the SLDV in future endeavors.

  14. Dimethylarginine dimethylaminohydrolase (DDAH) overexpression attenuates agricultural organic dust extract-induced inflammation.

    PubMed

    Bailey, Kl; Wyatt, Ta; Wells, Sm; Klein, Eb; Robinson, Je; Romberger, Dj; Poole, Ja

    2014-03-01

    Modern, industrialized farming practices have lead to working conditions that include high levels of airborne dust. Agricultural workers inhale these complex organic dusts on a daily basis, leading to airway inflammation and higher risk for developing chronic obstructive pulmonary disease. The mechanisms regulating the organic dust-induced airway inflammatory response are not well-defined. We investigated whether overexpression of dimethylarginine dimethylaminohydrolase (DDAH) would lead to diminished pulmonary inflammation in an animal model of organic dust extract exposure. We instilled wild-type (WT) and DDAH overexpressing mice with an aqueous organic dust extract (ODE) collected from a swine confinement building. We found that inflammatory indices such as neutrophil influx and inflammatory cytokine production was lower in the DDAH overexpressing mice compared to WT after organic dust extract (ODE) instillation. We went on to determine how DDAH was mediating the decrease in inflammation induced by ODE. PKCα and PKCε play an essential role in the ODE inflammatory response. In a model of lung slices from WT and DDAH overexpressing mice, we demonstrated an increase in PKCα and PKCε in the WT mice exposed to ODE. This increase was diminished in the DDAH overexpressing mice exposed to ODE. We also tested an important component of the ODE, peptidoglycan (PGN). We noted a similar decrease in neutrophils and inflammatory cytokines in the DDAH overexpressing animals instilled with PGN compared to WT. In conclusion, our studies found a role for DDAH in regulating the ODE-triggered activation of epithelial PKCα and PKCε, a previously unrecognized mechanism of action. This ultimately results in diminished pulmonary inflammation.

  15. Dimethylarginine dimethylaminohydrolase (DDAH) overexpression attenuates agricultural organic dust extract-induced inflammation

    PubMed Central

    Bailey, KL; Wyatt, TA; Wells, SM; Klein, EB; Robinson, JE; Romberger, DJ; Poole, JA

    2013-01-01

    Modern, industrialized farming practices have lead to working conditions that include high levels of airborne dust. Agricultural workers inhale these complex organic dusts on a daily basis, leading to airway inflammation and higher risk for developing chronic obstructive pulmonary disease. The mechanisms regulating the organic dust-induced airway inflammatory response are not well-defined. We investigated whether overexpression of dimethylarginine dimethylaminohydrolase (DDAH) would lead to diminished pulmonary inflammation in an animal model of organic dust extract exposure. We instilled wild-type (WT) and DDAH overexpressing mice with an aqueous organic dust extract (ODE) collected from a swine confinement building. We found that inflammatory indices such as neutrophil influx and inflammatory cytokine production was lower in the DDAH overexpressing mice compared to WT after organic dust extract (ODE) instillation. We went on to determine how DDAH was mediating the decrease in inflammation induced by ODE. PKCα and PKCε play an essential role in the ODE inflammatory response. In a model of lung slices from WT and DDAH overexpressing mice, we demonstrated an increase in PKCα and PKCε in the WT mice exposed to ODE. This increase was diminished in the DDAH overexpressing mice exposed to ODE. We also tested an important component of the ODE, peptidoglycan (PGN). We noted a similar decrease in neutrophils and inflammatory cytokines in the DDAH overexpressing animals instilled with PGN compared to WT. In conclusion, our studies found a role for DDAH in regulating the ODE-triggered activation of epithelial PKCα and PKCε, a previously unrecognized mechanism of action. This ultimately results in diminished pulmonary inflammation. PMID:25221746

  16. Cyberinfrastructure for Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.

    2009-01-01

    Since 2004 the NASA Airborne Science Program has been prototyping and using infrastructure that enables researchers to interact with each other and with their instruments via network communications. This infrastructure uses satellite links and an evolving suite of applications and services that leverage open-source software. The use of these tools has increased near-real-time situational awareness during field operations, resulting in productivity improvements and the collection of better data. This paper describes the high-level system architecture and major components, with example highlights from the use of the infrastructure. The paper concludes with a discussion of ongoing efforts to transition to operational status.

  17. Exposure to mineral sands dust particles

    NASA Astrophysics Data System (ADS)

    Dias da Cunha, K.; Barros Leite, C. V.; Zays, Z.

    2004-06-01

    The aim of this study is to characterize the airborne particles in a Brazilian region with high concentration of mineral sands (Buena village). In this study proton induced X-ray emission (PIXE), plasma desorption mass spectrometry and alpha spectrometry were used for analyses of airborne particles. The analyses of aerosol samples and lichen samples show that the inhabitants of the Buena village are exposed to airborne particles in the fine fraction of aerosols. The main anthropogenic sources of particles are the mineral sands processing plant and truck traffic, and natural sources as the sea, soil and the swamp. The results from the lichen samples show that at least during the last 15 years the inhabitants of the village have been exposed to monazite particles. The results from aerosols and lichens samples also suggested that the swamp is a source of 226Ra and 210Pb bearing particles besides the monazite dust.

  18. Multi-element analysis by inductively coupled plasma optical emission spectrometry of airborne particulate matter collected with a low-pressure cascade impactor.

    PubMed

    Robache, A; Mathé, F; Galloo, J C; Guillermo, R

    2000-10-01

    A method was developed for the elemental analysis of size segregated particles ranging from 0.03 to 10 microns. Sampling and analysis problems are discussed in this paper. Particles were collected with a Dekati low-pressure cascade impactor. PTFE filters coated with oleic acid were used as substrate. Particles were microwave digested in closed vessels. The optimum digestion mixture was composed of HNO3 (1 mL), HF (50 microL) and H2O (1 mL). The optimal power setting and digestion time were studied in order to achieve an efficient digestion. A ca. 35 min microwave digestion cycle at a 650 W maximum power allowed complete digestion of the samples. Special emphasis was placed on the pressure in the closed vessels to avoid sample losses. Solution samples were analysed by inductively coupled plasma optical emission spectrometry using an ultrasonic nebuliser for 18 elements (Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Sr, Ti, V, Zn). This procedure was tested with NIST Standard Reference Material 1648 Urban Particulate. Recoveries for certified elements ranged from 95 to 105% except for Al (90%). The influence of cascade impactor materials was investigated with 44 field samples. Strong artefacts due to contamination were shown for analysis at environmental concentrations of Al, Cr, Mn and Ni.

  19. Dust Studies in DIII-D Tokamak

    SciTech Connect

    Rudakov, D L; West, W P; Groth, M; Yu, J H; Boedo, J A; Bray, B D; Brooks, N H; Fenstermacher, M E; Hollmann, E M; Hyatt, A W; Krasheninnikov, S I; Lasnier, C J; Moyer, R A; Pigarov, A Y; Smirnov, R; Solomon, W M; Wong, C C

    2008-04-15

    Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark modeling, milligram amounts of micron-sized carbon dust have been injected into DIII-D discharges, leading to the core carbon density increase by a factor of 2-3. Following injection, dust trajectories in the divertor are mostly in the toroidal direction, consistent with the ion drag force. Dust from the injection is observed in the outboard midplane by a fast framing camera. The observed trajectories and velocities of the dust particles are in qualitative agreement with modeling by the 3D DustT code.

  20. Dust Studies in DIII-D Tokamak

    SciTech Connect

    Rudakov, D. L.; Yu, J. H.; Boedo, J. A.; Hollmann, E. M.; Krasheninnikov, S. I.; Moyer, R. A.; Pigarov, A. Yu.; Smirnov, R.; West, W. P.; Bray, B. D.; Brooks, N. H.; Hyatt, A. W.; Wong, C. P. C.; Groth, M.; Fenstermacher, M. E.; Lasnier, C. J.; Solomon, W. M.

    2008-09-07

    Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark modeling, milligram amounts of micron-sized carbon dust have been injected into DIII-D discharges, leading to the core carbon density increase by a factor of 2-3. Following injection, dust trajectories in the divertor are mostly in the toroidal direction, consistent with the ion drag force. Dust from the injection is observed in the outboard midplane by a fast framing camera. The observed trajectories and velocities of the dust particles are in qualitative agreement with modeling by the 3D DustT code.

  1. A Technique for Airborne Aerobiological Sampling

    ERIC Educational Resources Information Center

    Mill, R. A.; And Others

    1972-01-01

    Report of a study of airborne micro-organisms collected over the Oklahoma City Metropolitan area and immediate environments, to investigate the possibility that a cloud of such organisms might account for the prevalence of some respiratory diseases in and around urban areas. (LK)

  2. Rocket dust storms and detached layers in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Spiga, A.; Faure, J.; Madeleine, J.; Maattanen, A. E.; Forget, F.

    2012-12-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling with radiatively-active transported dust to predict the evolution of a local dust storm monitored by OMEGA onboard Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, in lieu of latent heating in moist convection on Earth. We propose to use the terminology "rocket dust storm", or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30 to 50 km). Combined to horizontal transport by large-scale winds, rocket dust storms form detached layers of dust reminiscent of those observed with instruments onboard Mars Global Surveyor and Mars Reconnaissance Orbiter. Detached layers are stable over several days owing to nighttime sedimentation being unable to counteract daytime convective transport, and to the resupply of convective energy at sunrise. The peak activity of rocket dust storms is expected in low-latitude regions at clear season, which accounts for the high-altitude tropical dust maximum unveiled by Mars Climate Sounder. Our findings on dust-driven deep convection have strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.ensity-scaled dust optical depth at local times 1400 1600 and 1800 (lat 2.5°S, Ls 135°) hortwave heating rate at local time 1500 and latitude 2.5°S.

  3. Quantification and Modelling of Fugitive Dust Emissions From Nickel Slag

    NASA Astrophysics Data System (ADS)

    Sanderson, R. S.; McKenna Neuman, C.

    2009-05-01

    Mining and smelting operations in Northern Ontario, and indeed worldwide, introduce a number of unique sources of fugitive dust and other aerosol pollutants into the surrounding environment from smokestacks, tailings, and slag dumps exposed to wind erosion. Fugitive dust represents a potential health hazard, and as such, mining companies are required to maintain inventories of dust emissions associated with their operations. The purpose of this study was to fully characterize the wind-induced fugitive dust emission rates of nickel slag collected from a slag dump at a smelting facility in Northern Ontario, as dependent on wind speed, surface roughness, duration of weathering, effects of mechanical disturbance, and exposure to rain. PM10 flux rates were measured through combined field monitoring and wind tunnel simulation. In both settings, airborne dust concentrations downwind of the source were measured using four vertically distributed DustTrak aerosol monitors. Wind speed was measured in the wind tunnel using a micro-pitot tube mounted on a programmable traversing slide, and in the field, using five vertically distributed cup anemometers mounted on a mast. The profiles of PM10 and wind speed were used to compute the vertical emission rate (Fv) using a finite difference method. The PM10 emission rates simulated in the laboratory were found to directly overlap those measured on site at the smelting facility over a range of wind speeds, suggesting that Fv values measured in wind tunnel simulations can be used in dispersion modelling with a reasonable degree of confidence. Although showing a strong positive correlation with wind speed, PM10 emissions from nickel slag were found to demonstrate an exponential, temporal decay immediately following any form of mechanical disturbance that resulted in exposure of the silt fraction of the material. Winnowing of this fraction left behind an armoured surface of coarse, non-erodible clasts. It was further determined that

  4. Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations

    NASA Astrophysics Data System (ADS)

    Ryder, C. L.; McQuaid, J. B.; Flamant, C.; Washington, R.; Brindley, H. E.; Highwood, E. J.; Marsham, J. H.; Parker, D. J.; Todd, M. C.; Banks, J. R.; Brooke, J. K.; Engelstaedter, S.; Estellés, V.; Formenti, P.; Garcia-Carreras, L.; Kocha, C.; Marenco, F.; Rosenberg, P.; Sodemann, H.; Allen, C. J. T.; Bourdon, A.; Bart, M.; Cavazos-Guerra, C.; Chevaillier, S.; Crosier, J.; Darbyshire, E.; Dean, A. R.; Dorsey, J. R.; Kent, J.; O'Sullivan, D.; Schepanski, K.; Szpek, K.; Woolley, A.

    2015-01-01

    The Fennec climate program aims to improve understanding of the Saharan climate system through a synergy of observations and modelling. We present a description of the Fennec airborne observations during 2011 and 2012 over the remote Sahara (Mauritania and Mali) and the advances in the understanding of mineral dust and boundary layer processes they have provided. Aircraft instrumentation aboard the UK FAAM BAe146 and French SAFIRE Falcon 20 is described, with specific focus on instrumentation specially developed and relevant to Saharan meteorology and dust. Flight locations, aims and associated meteorology are described. Examples and applications of aircraft measurements from the Fennec flights are presented, highlighting new scientific results delivered using a synergy of different instruments and aircraft. These include: (1) the first airborne measurement of dust particles sized up to 300 microns and associated dust fluxes in the Saharan atmospheric boundary layer (SABL), (2) dust uplift from the breakdown of the nocturnal low-level jet before becoming visible in SEVIRI satellite imagery, (3) vertical profiles of the unique vertical structure of turbulent fluxes in the SABL, (4) in-situ observations of processes in SABL clouds showing dust acting as CCN and IN at -15 °C, (5) dual-aircraft observations of the SABL dynamics, thermodynamics and composition in the Saharan heat low region (SHL), (6) airborne observations of a dust storm associated with a cold-pool (haboob) issued from deep convection over the Atlas, (7) the first airborne chemical composition measurements of dust in the SHL region with differing composition, sources (determined using Lagrangian backward trajectory calculations) and absorption properties between 2011 and 2012, (8) coincident ozone and dust surface area measurements suggest coarser particles provide a route for ozone depletion, (9) discrepancies between airborne coarse mode size distributions and AERONET sunphotometer retrievals under

  5. Airborne Endotoxin from Indoor and Outdoor Environments:Effect of Sample Dilution on the Kinetic Limulus Amebocyte Lysate (LAL) Assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne endotoxin in occupational environments are a potential respiratory hazard to individuals. In this study, total and inhalable airborne endotoxin samples were collected via filtration from inside animal housing units and downwind from agricultural production sites and a wastewater treatment ...

  6. Mars Airborne Prospecting Spectrometer

    NASA Astrophysics Data System (ADS)

    Steinkraus, J. M.; Wright, M. W.; Rheingans, B. E.; Steinkraus, D. E.; George, W. P.; Aljabri, A.; Hall, J. L.; Scott, D. C.

    2012-06-01

    One novel approach towards addressing the need for innovative instrumentation and investigation approaches is the integration of a suite of four spectrometer systems to form the Mars Airborne Prospecting Spectrometers (MAPS) for prospecting on Mars.

  7. Characteristics of tyre dust in polluted air: Studies by single particle mass spectrometry (ATOFMS)

    NASA Astrophysics Data System (ADS)

    Dall'Osto, Manuel; Beddows, David C. S.; Gietl, Johanna K.; Olatunbosun, Oluremi A.; Yang, Xiaoguang; Harrison, Roy M.

    2014-09-01

    There is a paucity of quantitative knowledge on the contributions of non-exhaust (abrasion and re-suspension) sources to traffic emissions. Abrasive emissions can be broadly categorised as tyre wear, brake wear and road dust/road surface wear. Current research often considers road dust and tyre dust as externally mixed particles, the former mainly composed of mineral matter and the latter solely composed of mainly organic matter and some trace elements. The aim of this work was to characterise tyre wear from both laboratory and field studies by using Aerosol Time-Of-Flight Mass Spectrometry (ATOFMS). Real-time single particle chemical composition was obtained from a set of rubber tyres rotating on a metal surface. Bimodal particle number size distributions peaking at 35 nm and 85 nm were obtained from SMPS/APS measurements over the range 6-20,000 nm. ATOFMS mass spectra of tyre wear in the particle size range 200-3000 nm diameter show peaks due to exo-sulphur compounds, nitrate, Zn and ions of high molecular weight (m/z > 100) attributed to organic polymers. Two large ATOFMS datasets collected from a number of outdoor studies were examined. The former was constituted of 48 road dust samples collected on the roads of London. The latter consisted of ATOFMS ambient air field studies from Europe, overall composed of more than 2,000,000 single particle mass spectra. The majority (95%) of tyre wear particles present in the road dust samples and atmospheric samples are internally mixed with metals (Li, Na, Ca, Fe, Ti), as well as phosphate. It is concluded that the interaction of tyres with the road surface creates particles internally mixed from two sources: tyre rubber and road surface materials. Measurements of the tyre rubber component alone may underestimate the contribution of tyre wear to concentrations of airborne particulate matter. The results presented are especially relevant for urban aerosol source apportionment and PM2.5 exposure assessment.

  8. Physical/chemical and microbiological analyses of dusts at a resource recover plant.

    PubMed

    Duckett, E J; Wagner, J; Welker, R; Rogers, B; Usdin, V

    1980-12-01

    Airborne dusts at a resource recovery pilot plant were sampled and analyzed to determine physical, chemical and microbiological characteristics. The sampling device was a multi-stage impactor equipped with a pre-collector. Dusts are primarily fibrous organic materials, predominantly of nonrespirable size. Microbiological aerosol concentrations are reported and discussed.

  9. A DUST-SETTLING CHAMBER FOR SAMPLING-INSTRUMENT COMPARISON STUDIES

    EPA Science Inventory

    Introduction: Few methods exist that can evenly and reproducibly deposit dusts onto surfaces for surface-sampling methodological studies. A dust-deposition chamber was designed for that purpose.

    Methods: A 1-m3 Rochester-type chamber was modified to produce high airborne d...

  10. Fungal and Bacterial Communities in Indoor Dust Follow Different Environmental Determinants

    PubMed Central

    Weikl, Fabian; Tischer, Christina; Probst, Alexander J.; Heinrich, Joachim; Markevych, Iana; Jochner, Susanne; Pritsch, Karin

    2016-01-01

    People spend most of their time inside buildings and the indoor microbiome is a major part of our everyday environment. It affects humans’ wellbeing and therefore its composition is important for use in inferring human health impacts. It is still not well understood how environmental conditions affect indoor microbial communities. Existing studies have mostly focussed on the local (e.g., building units) or continental scale and rarely on the regional scale, e.g. a specific metropolitan area. Therefore, we wanted to identify key environmental determinants for the house dust microbiome from an existing collection of spatially (area of Munich, Germany) and temporally (301 days) distributed samples and to determine changes in the community as a function of time. To that end, dust samples that had been collected once from the living room floors of 286 individual households, were profiled for fungal and bacterial community variation and diversity using microbial fingerprinting techniques. The profiles were tested for their association with occupant behaviour, building characteristics, outdoor pollution, vegetation, and urbanization. Our results showed that more environmental and particular