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Sample records for airborne chrysotile concentrations

  1. A study of airborne chrysotile concentrations associated with handling, unpacking, and repacking boxes of automobile clutch discs.

    PubMed

    Jiang, George C T; Madl, Amy K; Ingmundson, Kelsey J; Murbach, Dana M; Fehling, Kurt A; Paustenbach, Dennis J; Finley, Brent L

    2008-06-01

    Although automotive friction products (brakes and manual clutches) historically contained chrysotile asbestos, industrial hygiene surveys and epidemiologic studies of auto mechanics have consistently shown that these workers are not at an increased risk of developing asbestos-related diseases. Airborne asbestos levels during brake repair and brake parts handling have been well-characterized, but the potential exposure to airborne asbestos fibers during the handling of clutch parts has not been examined. In this study, breathing zone samples on the lapel of a volunteer worker (n=100) and area samples at bystander (n=50), remote area (n=25), and ambient (n=9) locations collected during the stacking, unpacking, and repacking of boxes of asbestos-containing clutches, and the subsequent cleanup and clothes handling, were analyzed by phase contrast microscopy (PCM) and transmission electron microscopy (TEM). In addition, fiber morphology and size distribution was evaluated using X-ray diffraction, polarized light microscopy, and ISO analytical methods. It was observed that the (1) airborne asbestos concentrations increased with the number of boxes unpacked and repacked, (2) repetitive stacking of unopened boxes of clutches resulted in higher asbestos concentrations than unpacking and repacking the boxes of clutches, (3) cleanup and clothes handling tasks yielded very low asbestos concentrations. Fiber size and morphology analyses showed that amphibole fibers were not detected in the clutches and that the vast majority (>95%) of the airborne chrysotile fibers were less than 20 microm in length. Applying the ratio of asbestos fibers:total fibers (including non-asbestos) as determined by TEM to the PCM results, it was found that 30-min average airborne chrysotile concentrations (PCM adjusted) were 0.026+/-0.004 f/cc or 0.100+/-0.017 f/cc for a worker unpacking and repacking 1 or 2 boxes of clutches, respectively. The 30-min PCM adjusted average airborne asbestos

  2. [Chrysotile asbestos: biological effects, the work environment highest allowable concentration and neoplasm risk].

    PubMed

    Woźniak, H; Wiecek, E

    2000-01-01

    The authors present the most essential data on physical and chemical properties of chrysotile, sources of its emission, the extent of occupational exposure, and biological effect, used in setting MAC values for chrysotile-containing dusts. Exploitable asbestos deposits do not exist in Poland, but admixtures of asbestos minerals have been found in some deposits of mineral raw materials located in the area of Lower Silesia (melafir, gabbro, dolomite. ore, nickel, magnesite, serpentinite). In the 1970s, about 100,000 tonnes of asbestos, containing 90% of chrysotile, were used annually in Poland. This figure decreased to 30,000 tonnes in 1991. In 1985 the use of crocidolite asbestos was stopped, and in 1999, the use of asbestos-containing products was banned by the virtue of the legal act. At present, the Minister of Economy in agreement with the Minister of Environmental Protection sets regularly the list of asbestos-containing products permitted for the production or in the customs area. Nowadays, the range of dust concentrations in plants which use asbestos products amounts to 0.1-0.6 mg/m3 for total dust and 0.002-0.07 f/cm3 for respirable mineral fibres; and during exploitation of rock raw material deposits 0.7-280 mg/m3, and 0.01-3.3 f/cm3, respectively. During the years 1976-96, 1520 cases of asbestos-related occupational diseases were diagnosed. This figure included 1314 cases of asbestosis, 154 cases of lung cancer and 52 cases of pleura mesothelioma. MAC values for chrysotile and chrysotile-containing dusts are: 0.2 f/cm3 and 1 mg/m3. PMID:11002475

  3. 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.

  4. Detection of chrysotile asbestos in workers urine

    SciTech Connect

    Finn, M.B.; Hallenbeck, W.H.

    1985-03-01

    Urinary asbestos concentrations were evaluated as an indicator of occupational exposure to chrysotile asbestos via inhalation and ingestion. Detection of asbestos in the urine represents the first step in developing a biological indicator of exposure. Such an indicator could be used to supplement exposure data from workplace air sampling. A biological indicator would be particularly valuable in evaluating workers with intermittent airborne asbestos exposures and in determining if airborne exposure results in penetration of asbestos through the lung or gastro-intestinal tract. Transmission electron microscopy was selected as the most sensitive technique for identification of all sizes of asbestos fibers which might appear in the urine. The levels of chrysotile asbestos detected in the urine of five workers were significantly greater than the asbestos concentrations in matched field blanks. Also, the workers urinary asbestos levels were significantly greater than the concentrations found in the control group. Finally, the levels of chrysotile asbestos detected in the urine of two of six controls were significantly greater than those in matched field blanks. Although the project was not specifically designed to correlate urinary and airborne asbestos concentrations, preliminary data indicated that a correlation did not exist between these factors.

  5. 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

  6. Chest imaging and lung function impairment after long-term occupational exposure to low concentrations of chrysotile.

    PubMed

    Spyratos, Dionisios; Chloros, Diamantis; Haidich, Bettina; Dagdilelis, Loukas; Markou, Stamatia; Sichletidis, Lazaros

    2012-01-01

    The aim of the present study was the investigation of radiographic findings in relation to lung function after occupational exposure to permissible levels of relatively pure chrysotile (0.5-3% amphiboles). We studied 266 out of the total 317 employees who have worked in an asbestos cement factory during the period 1968-2004 with chest x-ray, high-resolution computed tomography (HRCT) and lung function tests. Sensitivity of chest x-ray was 43% compared to HRCT. Abnormal HRCT findings were found in 75 subjects (67%) and were related to age, occupational exposure duration, and spirometric data. The presence of parenchymal or visceral pleural lesions (exclusively or as the predominant abnormality) was being accompanied by lower total lung capacity and diffusion capacity. HRCT was much more sensitive than chest x-ray for occupational chrysotile exposure. Lung function impairment was related with parenchymal but not with pleural HRCT abnormalities. PMID:22524648

  7. Follow up study of workers manufacturing chrysotile asbestos cement products.

    PubMed Central

    Gardner, M J; Winter, P D; Pannett, B; Powell, C A

    1986-01-01

    A cohort study has been carried out of 2167 subjects employed between 1941 and 1983 at an asbestos cement factory in England. The production process incorporated the use of chrysotile asbestos fibre only, except for a small amount of amosite during four months in 1976. Measured airborne fibre concentrations available since 1970 from personal samplers showed mean levels below 1 fibre/ml, although higher levels had probably occurred previously in certain areas of the factory. No excess of lung cancer was observed in the mortality follow up by comparison with either national or local death rates, and analyses of subgroups of the workforce by job, exposure level, duration of employment, duration since entry, or calendar years of employment gave no real suggestion of an asbestos related excess for this cause of death. There was one death from pleural mesothelioma and one with asbestosis mentioned as an associated cause on the death certificate, but neither is thought to be linked to asbestos exposure at this factory. Other suggested asbestos related cancers, such as laryngeal and gastrointestinal, did not show raised risks. Although the durations of exposure were short in this study, the findings are consistent with two other studies of workers exposed to low concentrations of chrysotile fibre in the manufacture of asbestos cement products which reported no excess mortality. PMID:3024695

  8. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    NASA Technical Reports Server (NTRS)

    James, John T.

    2008-01-01

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

  9. Evaluation of take-home exposure and risk associated with the handling of clothing contaminated with chrysotile asbestos.

    PubMed

    Sahmel, J; Barlow, C A; Simmons, B; Gaffney, S H; Avens, H J; Madl, A K; Henshaw, J; Lee, R J; Van Orden, D; Sanchez, M; Zock, M; Paustenbach, D J

    2014-08-01

    The potential for para-occupational (or take-home) exposures from contaminated clothing has been recognized for the past 60 years. To better characterize the take-home asbestos exposure pathway, a study was performed to measure the relationship between airborne chrysotile concentrations in the workplace, the contamination of work clothing, and take-home exposures and risks. The study included air sampling during two activities: (1) contamination of work clothing by airborne chrysotile (i.e., loading the clothing), and (2) handling and shaking out of the clothes. The clothes were contaminated at three different target airborne chrysotile concentrations (0-0.1 fibers per cubic centimeter [f/cc], 1-2 f/cc, and 2-4 f/cc; two events each for 31-43 minutes; six events total). Arithmetic mean concentrations for the three target loading levels were 0.01 f/cc, 1.65 f/cc, and 2.84 f/cc (National Institute of Occupational Health and Safety [NIOSH] 7402). Following the loading events, six matched 30-minute clothes-handling and shake-out events were conducted, each including 15 minutes of active handling (15-minute means; 0.014-0.097 f/cc) and 15 additional minutes of no handling (30-minute means; 0.006-0.063 f/cc). Percentages of personal clothes-handling TWAs relative to clothes-loading TWAs were calculated for event pairs to characterize exposure potential during daily versus weekly clothes-handling activity. Airborne concentrations for the clothes handler were 0.2-1.4% (eight-hour TWA or daily ratio) and 0.03-0.27% (40-hour TWA or weekly ratio) of loading TWAs. Cumulative chrysotile doses for clothes handling at airborne concentrations tested were estimated to be consistent with lifetime cumulative chrysotile doses associated with ambient air exposure (range for take-home or ambient doses: 0.00044-0.105 f/cc year). PMID:24517168

  10. AIRBORNE ASBESTOS CONCENTRATIONS DURING BUFFING OF RESILIENT FLOOR TILE

    EPA Science Inventory

    Although asbestos-containing resilient floor tiles are considered nonfriable, the frictional forces exerted on the tile during routine maintenance operations can generate asbestos-containing structures. tudy was conducted to determine the level of airborne asbestos concentrations...

  11. The carcinogenicity of chrysotile asbestos

    SciTech Connect

    Harington, J.S. )

    1991-12-31

    In in vitro test systems, chrysotile is markedly toxic, causes chromosomal aberrations, and is capable of inducing morphological and preneoplastic transformation. In carefully designed animal experiments, chrysotile produces lung cancer and mesothelioma as effectively as do the amphiboles tested. Human population studies do not refute these experimental results. Chrysotile asbestos is carcinogenic to humans, especially for the induction of lung cancer and mesothelioma in exposed populations. For cancers of other sites, with the exception of laryngeal and possibly gastrointestinal cancer, the evidence for association with exposure to all forms of asbestos, including chrysotile, is not yet adequate for evaluation.48 references.

  12. Chrysotile asbestos in serpentinite quarries: a case study in Valmalenco, Central Alps, Northern Italy.

    PubMed

    Cavallo, Alessandro; Rimoldi, Bianca

    2013-07-01

    The Valmalenco serpentinite (Central Alps, Northern Italy) is marketed worldwide as dimension and decorative stone. However, the same area was once subject to chrysotile asbestos mining, from the XIX century until 1975. Asbestos is a well-known carcinogen, and there is the possibility of releasing fibres during quarrying, subsequently exposing workers. From 2004 to 2011, extensive sampling and monitoring of quarry fronts, asbestos veins, commercial stones and airborne asbestos was carried out. Massive rock and vein samples were analyzed by a combined use of optical microscopy, X-ray powder diffraction (XRPD) and quantitative electron microscopy (SEM). Asbestos is concentrated almost exclusively in discrete horizons, that coincide with the main discontinuities of the rock mass. Commercial stones without fractures and veins are practically asbestos free, whereas there is a slight contamination (sometimes exceeding the 1000 ppm threshold) close to hydrothermal selvages. Quarry floors were always quite contaminated by chrysotile "beards" detached from the surface of the blocks. The airborne asbestos concentrations (PCM and SEM) were distributed over a wide range, mostly below the occupational exposure limit of 0.1 f ml(-1). Concentrations at the quarry property border or at the closest villages were always below the environmental exposure limit of 0.002 f ml(-1). The extreme thinness of chrysotile fibrils produced during quarrying activities, and the abundance of pseudo-fibrous antigorite cleavage fragments proved the SEM-EDS analytical procedure to be the most suitable. It is of crucial importance to avoid the interception of veins during quarrying and to remove all visible asbestos from the extracted blocks, before any further processing. PMID:23770928

  13. Exposures and mortality among chrysotile asbestos workers. Part II: mortality

    SciTech Connect

    Dement, J.M.; Harris, R.L. Jr.; Symons, M.J.; Shy, C.M.

    1983-01-01

    A retrospective cohort mortality study was conducted among a cohort of 1,261 white males employed one or more months in chrysotile asbestos textile operations and followed between 1940 and 1975. Statistically significant excess mortality was observed for all causes combined (standardized mortality ratio (SMR) . 150), lung cancer (SMR . 135), diseases of the circulatory system (SMR . 125), nonmalignant respiratory diseases (SMR . 294), and accidents (SMR . 134). Using estimated fiber exposure levels in conjunction with detailed worker job histories, exposure-response relationships were investigated. Strong exposure-response relationships for lung cancer and asbestos related non-malignant respiratory diseases were observed. Compared with data for chrysotile miners and millers, chrysotile textile workers were found to experience significantly greater lung cancer mortality at lower lifetime cumulative exposure levels. Factors such as differences in airborne fiber characteristics may partially account for the large differences in exposure response between textile workers and miners and millers.

  14. [Possiblity to forecast lung pathology via parameters of allowable length of exposure to chrysotile].

    PubMed

    Ibraev, S A; Otarov, E Zh; Zharylkasyn, Zh Zh; Koigel'dinova, Sh S; Kulov, D B; Kalishev, M G

    2015-01-01

    Studies of allowable (safe) length of service in occuptions of mining transport enterprise "Kostanaiskie mineral" JSC were conducted to forecast occurrence of dust lung diseases in workers exposed to chrysotile-asbestos dust. To calculate allowable length of service, the authors used values of average shift concentration of chrysotile-asbestos dust. Based on the calculated data of the allowable length of service in chrysotile-asbestos production, the authors forecasted course of dust lung diseases. PMID:26036015

  15. Chrysotile: its occurrence and properties as variables controlling biological effects.

    PubMed

    Langer, A M; Nolan, R P

    1994-08-01

    Chrysotile formation arises through serpentinization of ultramafics and silicified dolomitic limestones. Rock types tend to control the trace metal content and both the nature and amounts of admixed minerals in the ore, such as fibrous brucite (nemalite) and tremolite. Some associated minerals and trace metals are thought to play a role in biological potential. Tremolite, one of the important associated minerals, may occur with different morphological forms, called habits. These habits range from asbestiform (tremolite asbestos) to common blocky or non-fibrous form (tremolite cleavage fragments). The latter is most common in nature. Tremolite in chrysotile ore varies in habit and concentration, both factors determining the degree of risk following inhalation. Tremolite fibre is thought to be important in relation to the occurrence of mesothelioma. Chrysotile fibrils may vary in diameter. Dust clouds generated following manipulation vary in fibre number and surface area. Chrysotile fibres exhibit a range of physical characteristics. The fibre may be non-flexible ('stiff') and low in tensile strength ('brittle'), and may lack an ability to curl. This fibre, referred to as 'harsh', sheds water more quickly than its curly, flexible 'soft' variety. The behaviour of the harsh fibres is more amphibole-like and their splintery nature suggests an enhanced inhalation potential. Slip fibre ore from Canada tends to contain more fibrous brucite (nemalite) than cross-fibre ore in the same mine. Industrial manipulation, which includes chemical treatment, heating and milling, may impart new surface properties to chrysotile dusts. Biological potential may be enhanced (opening of fibre bundles) or reduced (disruption of surface bonds and lessened ability to interact with organic moieties). Leaching of magnesium from chrysotile occurs at a pH less than about 10. Chrysotile has been demonstrated to lose magnesium in vivo and undergo clearance from the lung. The biological potential of

  16. INTERACTIONS OF CHRYSOTILE AND BENZOPYRENE IN A HUMAN CELL CULTURE SYSTEMS

    EPA Science Inventory

    At concentrations of 100 micrograms/ml, NIEHS short chrysotile was more cytotoxic than NIEHS intermediate chrysotile (3% and 17% survival, respectively); B(a)P and B(e)P concentrations up to and including 10 micromoles were not cytotoxic. Simultaneous application of NIEHS short c...

  17. Health risk of chrysotile revisited

    PubMed Central

    Dunnigan, Jacques; Hesterberg, Thomas; Brown, Robert; Velasco, Juan Antonio Legaspi; Barrera, Raúl; Hoskins, John; Gibbs, Allen

    2013-01-01

    This review provides a basis for substantiating both kinetically and pathologically the differences between chrysotile and amphibole asbestos. Chrysotile, which is rapidly attacked by the acid environment of the macrophage, falls apart in the lung into short fibers and particles, while the amphibole asbestos persist creating a response to the fibrous structure of this mineral. Inhalation toxicity studies of chrysotile at non-lung overload conditions demonstrate that the long (>20 µm) fibers are rapidly cleared from the lung, are not translocated to the pleural cavity and do not initiate fibrogenic response. In contrast, long amphibole asbestos fibers persist, are quickly (within 7 d) translocated to the pleural cavity and result in interstitial fibrosis and pleural inflammation. Quantitative reviews of epidemiological studies of mineral fibers have determined the potency of chrysotile and amphibole asbestos for causing lung cancer and mesothelioma in relation to fiber type and have also differentiated between these two minerals. These studies have been reviewed in light of the frequent use of amphibole asbestos. As with other respirable particulates, there is evidence that heavy and prolonged exposure to chrysotile can produce lung cancer. The importance of the present and other similar reviews is that the studies they report show that low exposures to chrysotile do not present a detectable risk to health. Since total dose over time decides the likelihood of disease occurrence and progression, they also suggest that the risk of an adverse outcome may be low with even high exposures experienced over a short duration. PMID:23346982

  18. A case control study of lung cancer and exposure to chrysotile and amphibole at a slovenian asbestos-cement plant.

    PubMed

    Dodic Fikfak, M; Kriebel, D; Quinn, M M; Eisen, E A; Wegman, D H

    2007-04-01

    A lung cancer case-control study was conducted in a Slovenian asbestos-cement factory for which unusually good records of asbestos exposures were available. The cohort consisted of all 6714 workers employed at the Salonit Anhovo factory after 31 December 1946 who worked there for at least one day between 1964 and 1994. Fifty-eight histologically confirmed cases of primary lung cancer and 290 controls were selected from the cohort. Working life exposure histories to amphibole and chrysotile forms of asbestos were estimated separately. Airborne asbestos concentrations were low. For example, the arithmetic mean exposure to all forms of asbestos in the highest exposure period (1947-1971) was 1.2 f/cm(3). Chrysotile asbestos made up about 90% of this exposure (mean 1.1 f/cm(3)), whereas amphibole accounted for 10% (0.1 f/cm(3)). Comparing those above and below the 90 percentile of cumulative exposure, the odds ratios for all asbestos, chrysotile and amphibole were 1.5, 1.6 and 2.0, respectively, but confidence intervals were wide. There are only a few asbestos-lung cancer studies with high-quality exposure data and exposures in this low range. Though imprecise, the findings are important to the ongoing debate about asbestos risks. PMID:17351264

  19. 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

  20. Ambrosia airborne pollen concentration modelling and evaluation over Europe

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Viovy, Nicolas; Khvorostyanov, Dmitry; Colette, Augustin

    2014-05-01

    Native from North America, Ambrosia artemisiifolia L. (Common Ragweed) is an invasive annual weed introduced in Europe in the mid-nineteenth century. It has a very high spreading potential throughout Europe and releases very allergenic pollen leading to health problems for sensitive persons. Because of its health effects, it is necessary to develop modelling tools to be able to forecast ambrosia air pollen concentration and to inform allergy populations of allergenic threshold exceedance. This study is realised within the framework of the ATOPICA project (https://www.atopica.eu/) which is designed to provide first steps in tools and estimations of the fate of allergies in Europe due to changes in climate, land use and air quality. To calculate and predict airborne concentrations of ambrosia pollen, a chain of models has been built. Models have been developed or adapted for simulating the phenology (PMP phonological modelling platform), inter-annual production (ORCHIDEE vegetation model), release and airborne processes (CHIMERE chemical transport model) of ragweed pollen. Airborne pollens follow processes similar to air quality pollutants in CHIMERE with some adaptations. The detailed methodology, formulations and input data will be presented. A set of simulations has been performed to simulate airborne concentrations of pollens over long time periods on a large European domain. Hindcast simulations (2000 - 2012) driven by ERA-Interim re-analyses are designed to best simulate past periods airborne pollens. The modelled pollen concentrations are calibrated with observations and validated against additional observations. Then, 20-year long historical simulations (1986 - 2005) are carried out using calibrated ambrosia density distribution and climate model-driven weather in order to serve as a control simulation for future scenarios. By comparison with multi-annual observed daily pollen counts we have shown that the model captures well the gross features of the pollen

  1. Temporal variations of airborne particles concentration in the Brussels environment.

    PubMed

    Vanderstraeten, P; Lénelle, Y; Meurrens, A; Carati, D; Brenig, L; Offer, Z Y

    2007-09-01

    We report and analyze data on the PM10 fraction of airborne particles measured at five recording stations in the Brussels region from October 2002 till September 2003. These stations are representative of the various activity sectors of the Brussels urban area. The objective was the determination of the origin of the PM10 particles (particles up to 10 mum) that are recorded in that region in order to follow the EU directives concerning tolerance level of airborne particles concentration. In order to evaluate the impacts of local and external factors that inject solid particles in the atmosphere of Brussels we compared concentration data from working and not working (holidays) periods. Moreover, we also compared concentrations from periods of agricultural activity and rest in the Brabant provinces surrounding the Brussels region for various crop types. The results lead to the conclusion that the impact or urban traffic is rather limited while that of the agricultural activities is important. Moreover, there appears a clear-cut distinction between different types of crops. PMID:17180416

  2. Airborne asbestos levels in non-occupational environments in Japan.

    PubMed

    Kohyama, N

    1989-01-01

    Airborne asbestos levels in non-occupational environments in Japan were determined by analytical transmission electron microscopy (ATEM) for about 100 air samples from various outdoor settings. Asbestos fibres (chrysotile) were found in almost all samples. The fibre (mass) concentrations were in the range of 4-367 fibres per litre (0.02-47.2 ng/m3) with a geometric mean of 18 f/1 (0.3 ng/m3). The mass concentrations were similar to the earlier data reported from other countries. Samples from main roads showed extremely high asbestos concentrations and short fibre lengths compared with those of the other samples. This strongly suggested that braking of vehicles was a significant emission source of airborne asbestos. Laboratory experiments using a brake testing machine demonstrated that asbestos fibres were released during braking. In addition, the present study found high levels of airborne asbestos in some highly polluted areas, such as a serpentine quarry, a town adjacent to an asbestos mine, and factories making asbestos slate-board. On the other hand, chrysotile fibres were also found in air samples from a small isolated island in the Pacific Ocean as well as in ice samples from ten thousand years ago in Antarctica. These facts suggest that chrysotile fibres have been liberated both by industrial activities and natural weathering, and have circulated around the earth. PMID:2744826

  3. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants. Volume 3

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This report, prepared by the Committee on Toxicology of the National Research Council's Board on Environmental Studies and Toxicology, is in response to a request from NASA for guidelines to develop spacecraft maximum allowable concentrations (SMACs) for space-station contaminants. SMACs are used to provide guidance on allowable chemical exposures during normal operations and emergency situations. Short-term SMACs refer to concentrations of airborne substances (such as gas, vapor, or aerosol) that will not compromise the performance of specific tasks during emergency conditions lasting up to 24 hours. Long-term SMACs are intended to avoid adverse health effects (either immediate or delayed) and to avoid degradation in crew performance with continuous exposure in a closed space-station environment for as long as 180 days.

  4. Airborne particle concentrations at schools measured at different spatial scales

    NASA Astrophysics Data System (ADS)

    Buonanno, G.; Fuoco, F. C.; Morawska, L.; Stabile, L.

    2013-03-01

    Potential adverse effects on children health may result from school exposure to airborne particles. To address this issue, measurements in terms of particle number concentration, particle size distribution and black carbon (BC) concentrations were performed in three school buildings in Cassino (Italy) and its suburbs, outside and inside of the classrooms during normal occupancy and use. Additional time resolved information was gathered on ventilation condition, classroom activity, and traffic count data around the schools were obtained using a video camera. Across the three investigated school buildings, the outdoor and indoor particle number concentration monitored down to 4 nm and up to 3 μm ranged from 2.8 × 104 part cm-3 to 4.7 × 104 part cm-3 and from 2.0 × 104 part cm-3 to 3.5 × 104 part cm-3, respectively. The total particle concentrations were usually higher outdoors than indoors, because no indoor sources were detected. I/O measured was less than 1 (varying in a relatively narrow range from 0.63 to 0.74), however one school exhibited indoor concentrations higher than outdoor during the morning rush hours. Particle size distribution at the outdoor site showed high particle concentrations in different size ranges, varying during the day; in relation to the starting and finishing of school time two modes were found. BC concentrations were 5 times higher at the urban school compared with the suburban and suburban-to-urban differences were larger than the relative differences of ultrafine particle concentrations.

  5. Airborne nanoparticle concentrations in the manufacturing of polytetrafluoroethylene (PTFE) apparel.

    PubMed

    Vosburgh, Donna J H; Boysen, Dane A; Oleson, Jacob J; Peters, Thomas M

    2011-03-01

    One form of waterproof, breathable apparel is manufactured from polytetrafluoroethylene (PTFE) membrane laminated fabric using a specific process to seal seams that have been sewn with traditional techniques. The sealing process involves applying waterproof tape to the seam by feeding the seam through two rollers while applying hot air (600 °C). This study addressed the potential for exposure to particulate matter from this sealing process by characterizing airborne particles in a facility that produces more than 1000 lightweight PTFE rain jackets per day. Aerosol concentrations throughout the facility were mapped, breathing zone concentrations were measured, and hoods used to ventilate the seam sealing operation were evaluated. The geometric mean (GM) particle number concentrations were substantially greater in the sewing and sealing areas (67,000 and 188,000 particles cm⁻³)) compared with that measured in the office area (12,100 particles cm⁻³). Respirable mass concentrations were negligible throughout the facility (GM = 0.002 mg m⁻³) in the sewing and sealing areas). The particles exiting the final discharge of the facility's ventilation system were dominated by nanoparticles (number median diameter = 25 nm; geometric standard deviation of 1.39). The breathing zone particle number concentrations of the workers who sealed the sewn seams were highly variable and significantly greater when sealing seams than when conducting other tasks (p < 0.0001). The sealing workers' breathing zone concentrations ranged from 147,000 particles cm⁻³ to 798,000 particles cm⁻³, and their seam responsibility significantly influenced their breathing zone concentrations (p = 0.03). The finding that particle number concentrations were approximately equal outside the hood and inside the local exhaust duct indicated poor effectiveness of the canopy hoods used to ventilate sealing operations. PMID:21347955

  6. Airborne Nanoparticle Concentrations in the Manufacturing of Polytetrafluoroethylene (PTFE) Apparel

    PubMed Central

    Vosburgh, Donna J.H.; Boysen, Dane A.; Oleson, Jacob J.; Peters, Thomas M.

    2016-01-01

    One form of waterproof, breathable apparel is manufactured from polytetrafluoroethylene (PTFE) membrane laminated fabric, using a specific process to seal seams that have been sewn with traditional techniques. The sealing process involves applying waterproof tape to the seam by feeding the seam through two rollers while applying hot air (600°C). This study addressed the potential for exposure to particulate matter from this sealing process, by characterizing airborne particles in a facility that produces over 1,000 lightweight PTFE rain jackets per day. Aerosol concentrations throughout the facility were mapped, breathing zone concentrations were measured, and hoods used to ventilate the seam sealing operation were evaluated. The geometric mean (GM) particle number concentrations were substantially greater in the sewing and sealing areas (67,000 and 188,000 particles cm−3) compared to that measured in the office area (12,100 particles cm−3). Respirable mass concentrations were negligible throughout the facility (GM=0.002 mg m−3 in the sewing and sealing areas). The particles exiting the final discharge of the facility's ventilation system were dominated by nanoparticles (number median diameter = 25 nm; geometric standard deviation of 1.39). The breathing zone particle number concentrations of the workers who sealed the sewn seams were highly variable and significantly greater when sealing seams than when conducting other tasks (p<0.0001). The sealing workers’ breathing zone concentrations ranged from 147,000 particles cm−3 to 798,000 particles cm−3, and their seam responsibility significantly influenced their breathing zone concentrations (p=0.03). The finding that particle number concentrations were approximately equal outside the hood and inside the local exhaust duct indicated poor effectiveness of the canopy hoods used to ventilate sealing operations. PMID:21347955

  7. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants. Volume 3

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Aeronautics and Space Administration (NASA) is aware of the potential toxicological hazards to humans that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing Spacecraft Maximum Allowable Concentrations (SMAC's) for contaminants, and to review SMAC's for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to this request, the NRC first developed criteria and methods for preparing SMAC's for spacecraft contaminants, published in its 1992 report Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. Since then, the Subcommittee on Spacecraft Maximum Allowable Concentrations has been reviewing NASA's documentation of chemical-specific SMAC's as described in the Introduction to this volume. This report is the third volume in the series Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. The first volume was published in 1994 and the second in 1996.

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

    PubMed

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

    2010-11-01

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

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

    NASA Technical Reports Server (NTRS)

    1996-01-01

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

  10. Modelling airborne concentration and deposition rate of maize pollen

    NASA Astrophysics Data System (ADS)

    Jarosz, Nathalie; Loubet, Benjamin; Huber, Laurent

    2004-10-01

    The introduction of genetically modified (GM) crops has reinforced the need to quantify gene flow from crop to crop. This requires predictive tools which take into account meteorological conditions, canopy structure as well as pollen aerodynamic characteristics. A Lagrangian Stochastic (LS) model, called SMOP-2D (Stochastic Mechanistic model for Pollen dispersion and deposition in 2 Dimensions), is presented. It simulates wind dispersion of pollen by calculating individual pollen trajectories from their emission to their deposition. SMOP-2D was validated using two field experiments where airborne concentration and deposition rate of pollen were measured within and downwind from different sized maize (Zea mays) plots together with micrometeorological measurements. SMOP-2D correctly simulated the shapes of the concentration profiles but generally underestimated the deposition rates in the first 10 m downwind from the source. Potential explanations of this discrepancy are discussed. Incorrect parameterisation of turbulence in the transition from the crop to the surroundings is probably the most likely reason. This demonstrates that LS models for particle transfer need to be coupled with air-flow models under complex terrain conditions.

  11. Measurement of airborne particle concentrations near the Sunset Crater volcano, Arizona.

    PubMed

    Benke, Roland R; Hooper, Donald M; Durham, James S; Bannon, Donald R; Compton, Keith L; Necsoiu, Marius; McGinnis, Ronald N

    2009-02-01

    Direct measurements of airborne particle mass concentrations or mass loads are often used to estimate health effects from the inhalation of resuspended contaminated soil. Airborne particle mass concentrations were measured using a personal sampler under a variety of surface-disturbing activities within different depositional environments at both volcanic and nonvolcanic sites near the Sunset Crater volcano in northern Arizona. Focused field investigations were performed at this analog site to improve the understanding of natural and human-induced processes at Yucca Mountain, Nevada. The level of surface-disturbing activity was found to be the most influential factor affecting the measured airborne particle concentrations, which increased over three orders of magnitude relative to ambient conditions. As the surface-disturbing activity level increased, the particle size distribution and the majority of airborne particle mass shifted from particles with aerodynamic diameters less than 10 mum (0.00039 in) to particles with aerodynamic diameters greater than 10 mum (0.00039 in). Under ambient conditions, above average wind speeds tended to increase airborne particle concentrations. In contrast, stronger winds tended to decrease airborne particle concentrations in the breathing zone during light and heavy surface-disturbing conditions. A slight increase in the average airborne particle concentration during ambient conditions was found above older nonvolcanic deposits, which tended to be finer grained than the Sunset Crater tephra deposits. An increased airborne particle concentration was realized when walking on an extremely fine-grained deposit, but the sensitivity of airborne particle concentrations to the resuspendible fraction of near-surface grain mass was not conclusive in the field setting when human activities disturbed the bulk of near-surface material. Although the limited sample size precluded detailed statistical analysis, the differences in airborne particle

  12. Analysis of airborne pollen concentrations in Zagreb, Croatia, 2002.

    PubMed

    Peternel, Renata; Culig, Josip; Mitić, Bozena; Vukusić, Ivan; Sostar, Zvonimir

    2003-01-01

    Employing the volumetric method by use of a Hirst sampler, a total of 71,286 pollen grains, as many as 94.20% of them allergenic, were recorded in the air samples from the city of Zagreb during the 2002 pollen season. Among identified pollen of 35 plant species/genera/families, 23 were allergenic: Taxus/Juniperus, Alnus sp., Fraxinus sp., Betula sp., Corylus sp., Poaceae, Urticaceae, Artemisia sp., Ambrosia sp., Carpinus sp., Castanea sp., Chenopodiaceae, Salix sp., Populus sp., Ulmus sp., Juglans sp., Quercus sp., Platanus sp., Fagus sp., Plantago sp., Pinus sp., Picea sp. and Abies sp. The pollen of these plants also cause the majority of pollinosis in Europe. Study results and the pollen calendar designed for the 2002 pollen season for the City of Zagreb provide useful data for allergologists to reach an accurate diagnosis. The calendar also provides timely information on airborne pollen types and air concentrations for individuals with pollen hypersensitivity, thus allowing them to adjust their daily activities so as to minimize their contact with allergens and improve their quality of life both at home and at work. PMID:12852741

  13. Airborne fibre and asbestos concentrations in system built schools

    NASA Astrophysics Data System (ADS)

    Burdett, Garry; Cottrell, Steve; Taylor, Catherine

    2009-02-01

    This paper summarises the airborne fibre concentration data measured in system built schools that contained asbestos insulation board (AIB) enclosed in the support columns by a protective steel casing. The particular focus of this work was the CLASP (Consortium of Local Authorities Special Programme) system buildings. A variety of air monitoring tests were carried out to assess the potential for fibres to be released into the classroom. A peak release testing protocol was adopted that involved static sampling, while simulating direct impact disturbances to selected columns. This was carried out before remediation, after sealing gaps and holes in and around the casing visible in the room (i.e. below ceiling level) and additionally round the tops of the columns, which extended into the suspended ceiling void. Simulated and actual measurements of worker exposures were also undertaken, while sealing columns, carrying out cleaning and maintenance work in the ceiling voids. Routine analysis of these air samples was carried out by phase contrast microscopy (PCM) with a limited amount of analytical transmission electron microscopy (TEM) analysis to confirm whether the fibres visible by PCM were asbestos or non-asbestos. The PCM fibre concentrations data from the peak release tests showed that while direct releases of fibres to the room air can occur from gaps and holes in and around the column casings, sealing is an effective way of minimising releases to below the limit of quantification (0.01 f/ml) of the PCM method for some 95% of the tests carried out. Sealing with silicone filler and taping any gaps and seams visible on the column casing in the room, also gave concentrations below the limit of quantification (LOQ) of the PCM method for 95% of the tests carried out. The data available did not show any significant difference between the PCM fibre concentrations in the room air for columns that had or had not been sealed in the ceiling void, as well as in the room

  14. Biodurability of chrysotile and tremolite asbestos

    NASA Astrophysics Data System (ADS)

    Oze, C.; Solt, K.

    2008-12-01

    Chrysotile and tremolite asbestos represent two mineralogical categories of regulated asbestos commonly evaluated in epidemiological, toxicological, and pathological studies. Lung and digestive fluids are undersaturated with respect to chrysotile and tremolite asbestos (i.e. dissolution is thermodynamically favorable), where the dissolution kinetics control the durability of these minerals in respiratory and gastric systems. Here we examined the biodurability of chrysotile and tremolite asbestos in simulated body fluids (SBFs) as a function of mineral surface area over time. Batch experiments in simulated gastric fluid (SGF; HCl and NaCl solution at pH 1.2) and simulated lung fluid (SLF; a modified Gamble's solution at pH 7.4) were performed at 37°C over 720 hours. The rate-limiting step of Si release for both minerals was used to determine and compare dissolution rates. Chrysotile and tremolite asbestos are less biodurable in SGF compared to SLF. Based on equal suspension densities (surface area per volume of solution, m2 L- 1), chrysotile undergoes dissolution approximately 44 times faster than tremolite asbestos in SGF; however, amphibole asbestos dissolves approximately 6 times faster than chrysotile in SLF. Provided identical fiber dimensions, fiber dissolution models demonstrate that chrysotile is more biodurable in SLF and less biodurable in SGF compared to tremolite asbestos. Overall, the methodology employed here provides an alternative means to evaluate asbestos material fiber lifetimes based on mineral surface considerations.

  15. Selection of respiratory protection devices for use in very high concentrations of airborne plutonium.

    PubMed

    Bianconi, C J

    2000-08-01

    This paper focuses on the proper selection of respiratory protection devices for use in very high concentrations of airborne plutonium. Special attention is given to the determination of levels at which airborne plutonium presents a hazard that is immediately dangerous to life or health. PMID:10910403

  16. Evaluation of exposure to the airborne asbestos in an asbestos cement sheet manufacturing industry in Iran.

    PubMed

    Panahi, Davood; Kakooei, Hossein; Marioryad, Hossein; Mehrdad, Ramin; Golhosseini, Mohammad

    2011-07-01

    Iran imports nearly 55,000 tons of Chrysotile asbestos per year and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, airborne asbestos concentrations during AC sheet manufacturing were measured. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM), with energy-dispersive X-ray analysis. Airborne total fiber concentrations of 45 personal samples were analyzed by phase contrast microscopy. The results have highlighted that 15.5% of samples exceed the threshold limit value (TLV) established the American Conference of Governmental Industrial Hygienists, which is 0.1 fiber per milliliter (f/ml). Personal monitoring of asbestos fiber levels indicated a ranged from 0.02 ± 0.01 to 0.16 ± 0.03 f/ml. The geometrical mean was 0.05 ± 1.36 f/ml, which is considerably lower than the TLV. SEM data demonstrate that the fibrous particles consisted, approximately, of Chrysotile (55.89%) and amphiboles (44.11%). We conclude that the industrial consumption of imported Chrysotile asbestos is responsible for the high airborne amphibole asbestos levels in the AC sheet industry. More research is needed to improve characterization of occupational exposures by fiber size and concentration in a variety of industries. PMID:20852930

  17. Chronic effects of dietary exposure to amosite and chrysotile asbestos in Syrian golden hamsters.

    PubMed Central

    McConnell, E E; Shefner, A M; Rust, J H; Moore, J A

    1983-01-01

    Bioassays of amosite, short-range (SR), intermediate-range (IR) or intermediate-range chrysotile asbestos in combination with the intestinal carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were conducted with male and female Syrian golden hamsters. Amosite and both forms of chrysotile asbestos were administered at a concentration of 1% in pelleted diet for the entire lifetime of the hamsters starting with mothers of the test animals. Group sizes varied from 125-254. There was no adverse effect on body weight gain or survival by either type of asbestos or by IR chrysotile asbestos in combination with DMH. A significant increase (p less than 0.05) in adrenal cortical tumors was observed in male hamsters exposed to SR and IR chrysotile asbestos and in females treated with IR chrysotile asbestos when compared to the pooled control groups. However, statistical significance (p less than 0.05) was lost when these dosed groups were compared with temporal control groups. Neither of the male or female amosite asbestos groups showed increased neoplasia in any tissue or organ compared to the control groups. The cocarcinogen studies using IR chrysotile asbestos and 1,2-dimethylhydrazine dihydrochloride were considered inadequate because there was no increase in intestinal neoplasia in the DMH group. PMID:6319115

  18. A Quantitative Dynamic Simulation of Bremia lactucae Airborne Conidia Concentration above a Lettuce Canopy.

    PubMed

    Fall, Mamadou Lamine; Van der Heyden, Hervé; Carisse, Odile

    2016-01-01

    Lettuce downy mildew, caused by the oomycete Bremia lactucae Regel, is a major threat to lettuce production worldwide. Lettuce downy mildew is a polycyclic disease driven by airborne spores. A weather-based dynamic simulation model for B. lactucae airborne spores was developed to simulate the aerobiological characteristics of the pathogen. The model was built using the STELLA platform by following the system dynamics methodology. The model was developed using published equations describing disease subprocesses (e.g., sporulation) and assembled knowledge of the interactions among pathogen, host, and weather. The model was evaluated with four years of independent data by comparing model simulations with observations of hourly and daily airborne spore concentrations. The results show an accurate simulation of the trend and shape of B. lactucae temporal dynamics of airborne spore concentration. The model simulated hourly and daily peaks in airborne spore concentrations. More than 95% of the simulation runs, the daily-simulated airborne conidia concentration was 0 when airborne conidia were not observed. Also, the relationship between the simulated and the observed airborne spores was linear. In more than 94% of the simulation runs, the proportion of the linear variation in the hourly-observed values explained by the variation in the hourly-simulated values was greater than 0.7 in all years except one. Most of the errors came from the deviation from the 1:1 line, and the proportion of errors due to the model bias was low. This model is the only dynamic model developed to mimic the dynamics of airborne inoculum and represents an initial step towards improved lettuce downy mildew understanding, forecasting and management. PMID:26953691

  19. A Quantitative Dynamic Simulation of Bremia lactucae Airborne Conidia Concentration above a Lettuce Canopy

    PubMed Central

    Fall, Mamadou Lamine; Van der Heyden, Hervé; Carisse, Odile

    2016-01-01

    Lettuce downy mildew, caused by the oomycete Bremia lactucae Regel, is a major threat to lettuce production worldwide. Lettuce downy mildew is a polycyclic disease driven by airborne spores. A weather-based dynamic simulation model for B. lactucae airborne spores was developed to simulate the aerobiological characteristics of the pathogen. The model was built using the STELLA platform by following the system dynamics methodology. The model was developed using published equations describing disease subprocesses (e.g., sporulation) and assembled knowledge of the interactions among pathogen, host, and weather. The model was evaluated with four years of independent data by comparing model simulations with observations of hourly and daily airborne spore concentrations. The results show an accurate simulation of the trend and shape of B. lactucae temporal dynamics of airborne spore concentration. The model simulated hourly and daily peaks in airborne spore concentrations. More than 95% of the simulation runs, the daily-simulated airborne conidia concentration was 0 when airborne conidia were not observed. Also, the relationship between the simulated and the observed airborne spores was linear. In more than 94% of the simulation runs, the proportion of the linear variation in the hourly-observed values explained by the variation in the hourly-simulated values was greater than 0.7 in all years except one. Most of the errors came from the deviation from the 1:1 line, and the proportion of errors due to the model bias was low. This model is the only dynamic model developed to mimic the dynamics of airborne inoculum and represents an initial step towards improved lettuce downy mildew understanding, forecasting and management. PMID:26953691

  20. Modeling Airborne Beryllium Concentrations From Open Air Dynamic Testing

    NASA Astrophysics Data System (ADS)

    Becker, N. M.

    2003-12-01

    A heightened awareness of airborne beryllium contamination from industrial activities was reestablished during the late 1980's and early 1990's when it became recognized that Chronic Beryllium Disease (CBD) had not been eradicated, and that the Occupational Health and Safety Administration standards for occupational air exposure to beryllium may not be sufficiently protective. This was in response to the observed CBD increase in multiple industrial settings where beryllium was manufactured and/or machined, thus producing beryllium particulates which are then available for redistribution by airborne transport. Sampling and modeling design activities were expanded at Los Alamos National Laboratory in New Mexico to evaluate potential airborne beryllium exposure to workers who might be exposed during dynamic testing activities associated with nuclear weapons Stockpile Stewardship. Herein is presented the results of multiple types of collected air measurements that were designed to characterize the production and dispersion of beryllium used in components whose performance is evaluated during high explosive detonation at open air firing sites. Data from fallout, high volume air, medium volume air, adhesive film, particle size impactor, and fine-particulate counting techniques will be presented, integrated, and applied in dispersion modeling to assess potential onsite and offsite personal exposures resulting from dynamic testing activities involving beryllium.

  1. Effects of chrysotile and acid-treated chrysotile on macrophage cultures

    PubMed Central

    Beck, E. G.; Holt, P. F.; Nasrallah, E. T.

    1971-01-01

    Beck, E. G., Holt, P. F., and Nasrallah, E. T. (1971).Brit. J. industr. Med.,28, 179-185. Effects of chrysotile and acid-treated chrysotile on macrophage cultures. The addition of chrysotile asbestos to monolayer cultures of peritoneal and alveolar macrophages produces an increase in membrane permeability, as measured by eosin uptake and lactic dehydrogenase activity of the supernatant fluid. The lactate synthesis is increased, however. It is suggested that the permeability of the cell membrane is increased while dust particles are being phagocytosed, which may take several hours when the particles are fibrous, but that this does not imply cell damage. Treatment of chrysotile with acid, which leaves a silica surface, results in a product that reduces lactate synthesis, implying cytotoxicity. This change is counteracted by poly(2-vinyl-pyridine 1-oxide). The polymer does not affect the properties of the native chrysotile. PMID:5572686

  2. Absolute tracer dye concentration using airborne laser-induced water Raman backscatter

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.

    1981-01-01

    The use of simultaneous airborne-laser-induced dye fluorescence and water Raman backscatter to measure the absolute concentration of an ocean-dispersed tracer dye is discussed. Theoretical considerations of the calculation of dye concentration by the numerical comparison of airborne laser-induced fluorescence spectra with laboratory spectra for known dye concentrations using the 3400/cm OH-stretch water Raman scatter as a calibration signal are presented which show that minimum errors are obtained and no data concerning water mass transmission properties are required when the laser wavelength is chosen to yield a Raman signal near the dye emission band. Results of field experiments conducted with an airborne conical scan lidar over a site in New York Bight into which rhodamine dye had been injected in a study of oil spill dispersion are then indicated which resulted in a contour map of dye concentrations, with a minimum detectable dye concentration of approximately 2 ppb by weight.

  3. Ambient airborne solids concentrations including volcanic ash at Hanford, Washington sampling sites subsequent to the Mount St. Helens eruption

    NASA Technical Reports Server (NTRS)

    Sehmel, G. A.

    1982-01-01

    Airborne solids concentrations were measured on a near daily basis at two Hanford, Washington sites after the eruption of Mount St. Helens on May 18, 1980. These sites are about 211 km east of Mount St. Helens. Collected airborne solids included resuspended volcanic ash plus normal ambient solids. Average airborne solids concentrations were greater at the Hanford meteorological station sampling site which is 24 km northwest of the Horn Rapids dam sampling site. These increased concentrations reflect the sampling site proximity to greater ash fallout depths. Both sites are in low ash fallout areas although the Hanford meteorological station site is closer to the greater ash fallout areas. Airborne solids concentrations were decreased by rain, but airborne solids concentrations rapidly increased as surfaces dried. Airborne concentrations tended to become nearly the same at both sampling sites only for July 12 and 13.

  4. Airborne endotoxin concentrations at a large open-lot dairy in southern idaho.

    PubMed

    Dungan, Robert S; Leytem, April B

    2009-01-01

    Endotoxins are derived from gram-negative bacteria and are a potential respiratory health risk for animals and humans. To determine the potential for endotoxin transport from a large open-lot dairy, total airborne endotoxin concentrations were determined at an upwind location (background) and five downwind locations on three separate days. The downwind locations were situated at of the edge of the lot, 200 and 1390 m downwind from the lot, and downwind from a manure composting area and wastewater holding pond. When the wind was predominantly from the west, the average endotoxin concentration at the upwind location was 24 endotoxin units (EU) m(-3), whereas at the edge of the lot on the downwind side it was 259 EU m(-3). At 200 and 1390 m downwind from the edge of the lot, the average endotoxin concentrations were 168 and 49 EU m(-3), respectively. Average airborne endotoxin concentrations downwind from the composting site (36 EU m(-3)) and wastewater holding pond (89 EU m(-3)) and 1390 m from the edge of the lot were not significantly different from the upwind location. There were no significant correlations between ambient weather data collected and endotoxin concentrations over the experimental period. The downwind data show that the airborne endotoxin concentrations decreased exponentially with distance from the lot edge. Decreasing an individual's proximity to the dairy should lower their risk of airborne endotoxin exposure and associated health effects. PMID:19643758

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

    PubMed

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

    2016-07-01

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

  6. Adsorption of proteins by chrysotile and crocidolite: role of molecular weight and charge density

    SciTech Connect

    Valerio, F.; Balducci, D.; Lazzarotto, A.

    1987-12-01

    Transferrin ..gamma..-globulin, fibrinogen, aldolase, albumin, and cytochrome c at concentration of 0.45 ..mu..Mole/liter were treated with chrysotile and crocidolite fibers. Specific adsorption for each protein and correlations between protein molecular weight and charge density in experimental conditions were evaluated. Chrysotile showed the highest adsorption capability, particularly toward albumin and cytochrome c. Affinity for fibers was poorly linked to protein molecular weight; on the contrary, a good correlation with protein charge density was found. The sign of charge on fibers and proteins seemed to play a minor role in adsorption.

  7. Concentration and size distribution of total airborne microbes in hazy and foggy weather.

    PubMed

    Dong, Lijie; Qi, Jianhua; Shao, Congcong; Zhong, Xi; Gao, Dongmei; Cao, Wanwan; Gao, Jiawei; Bai, Ran; Long, Gaoyuan; Chu, Congcong

    2016-01-15

    Atmospheric bioaerosol particles were collected using a bioaerosol sampler from Oct. 2013 to Aug. 2014 in the coastal region of Qingdao. The total microbes were measured using an epifluorescence microscope after staining with DAPI (4',6-diamidino-2-phenylindole). The concentration of total airborne microbes showed seasonal variation, with the highest value in winter and the lowest in summer. The mean concentration of total microbes was 6.55 × 10(5)Cells/m(3) on non-hazy days. The total microbe concentration increased to 7.09 × 10(5) and 9.00 × 10(5)Cells/m(3) on hazy and foggy days, respectively. The particle sizes of the total microbes presented a bimodal distribution on sunny days, with one peak at 1.1-2.1 μm and another at 4.7-7.0 μm. The size distribution of total microbes showed an increase in the fine fraction on hazy days and an increase in the coarse fraction on foggy days. However, the size distribution became unimodal during a heating period. Spearman correlation analysis showed that temperature and O3 had a significant negative correlation with the airborne microbe concentration, while PM2.5, SO2, NO2, CO and the air quality index (AQI) had significant positive correlations with the airborne microbe concentration during hazy days. The increased number of airborne microbes will affect the air quality on hazy days. PMID:26473703

  8. Surface and Airborne Arsenic Concentrations in a Recreational Site near Las Vegas, Nevada, USA

    PubMed Central

    Goossens, Dirk

    2015-01-01

    Elevated concentrations of arsenic, up to 7058 μg g-1 in topsoil and bedrock, and more than 0.03 μg m-3 in air on a 2-week basis, were measured in the Nellis Dunes Recreation Area (NDRA), a very popular off-road area near Las Vegas, Nevada, USA. The elevated arsenic concentrations in the topsoil and bedrock are correlated to outcrops of yellow sandstone belonging to the Muddy Creek Formation (≈ 10 to 4 Ma) and to faults crossing the area. Mineralized fluids moved to the surface through the faults and deposited the arsenic. A technique was developed to calculate airborne arsenic concentrations from the arsenic content in the topsoil. The technique was tested by comparing calculated with measured concentrations at 34 locations in the NDRA, for 3 periods of 2 weeks each. We then applied it to calculate airborne arsenic concentrations for more than 500 locations all over the NDRA. The highest airborne arsenic concentrations occur over sand dunes and other zones with a surficial layer of aeolian sand. Ironically these areas show the lowest levels of arsenic in the topsoil. However, they are highly susceptible to wind erosion and emit very large amounts of sand and dust during episodes of strong winds, thereby also emitting much arsenic. Elsewhere in the NDRA, in areas not or only very slightly affected by wind erosion, airborne arsenic levels equal the background level for airborne arsenic in the USA, approximately 0.0004 μg m-3. The results of this study are important because the NDRA is visited by more than 300,000 people annually. PMID:25897667

  9. Year-long assessment of airborne endotoxin at a concentrated dairy operation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the increasing prevalence of concentrated animal feeding operations (CAFOs), concern over bioaerosols drifting in downwind plumes is gaining attention as they may cause health effects in humans and livestock. In this study, we monitored total airborne endotoxins at upwind and downwind locations...

  10. AIRBORNE ASBESTOS CONCENTRATIONS DURING BUFFING, BURNISHING, AND STRIPPING OF RESILIENT FLOOR TILE

    EPA Science Inventory

    This study was conducted to evaluate airborne asbestos concentrations during low-speed spray-buffing, ultra high-speed burnishing, and wet-stripping of asbestos-containing resilient floor tile under preexisting and prepared levels of floor care maintenance. ow-speed spray-buffing...

  11. A Computer Code to Estimate Environmental Concentration and Dose Due to Airborne Release of Radioactive Material.

    1991-03-15

    Version 00 ORION-II was developed to estimate environmental concentration and dose due to airborne release of radioactive material from multiple sources of the nuclear fuel cycle facilities. ORION-II is an updated version of ORION and is applicable to the sensitivity study of dose assessment at nuclear fuel cycle facilities.

  12. AIRBORNE ASBESTOS CONCENTRATIONS DURING BUFFING, BURNISHING, AND STRIPPING OF RESILIENT FLOOR TILE

    EPA Science Inventory

    The study was conducted to evaluate airborne asbestos concentrations during low-speed spray-buffing, ultra high-speed burnishing, and wet-stripping of asbestos-containing resilient floor tile under pre-existing and prepared levels of floor care maintenance. Low-speed spray-buffin...

  13. Concentrations of airborne endotoxin and microorganisms at a 10,000 cow open-freestall dairy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confined animal production systems produce elevated bioaerosol concentrations, which are a potential respiratory health risk to individuals on site and downwind. In this study, airborne endotoxin and microorganisms were collected during the spring, summer, and fall at a large open-freestall dairy i...

  14. Airborne endotoxin concentrations at a large open-lot dairy in southern Idaho

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endotoxins are derived from Gram-negative bacteria and are a potential respiratory health risk for animals and humans. To determine the potential for endotoxin transport from a large open lot dairy, airborne endotoxin concentrations were determined at an upwind location (background) and five downwi...

  15. Qualitative and quantitative methodologies for determination of airborne microorganisms at concentrated animal-feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The generation of bioaerosols from concentrated animal feeding operations (CAFOs) is a concern from a human and animal health perspective. To better understand the airborne microorganisms found in these environments, a number of collection and analytical techniques have been utilized and will be di...

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

    NASA Technical Reports Server (NTRS)

    1994-01-01

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

  17. A method to quantify infectious airborne pathogens at concentrations below the threshold of quantification by culture

    PubMed Central

    Cutler, Timothy D.; Wang, Chong; Hoff, Steven J.; Zimmerman, Jeffrey J.

    2013-01-01

    In aerobiology, dose-response studies are used to estimate the risk of infection to a susceptible host presented by exposure to a specific dose of an airborne pathogen. In the research setting, host- and pathogen-specific factors that affect the dose-response continuum can be accounted for by experimental design, but the requirement to precisely determine the dose of infectious pathogen to which the host was exposed is often challenging. By definition, quantification of viable airborne pathogens is based on the culture of micro-organisms, but some airborne pathogens are transmissible at concentrations below the threshold of quantification by culture. In this paper we present an approach to the calculation of exposure dose at microbiologically unquantifiable levels using an application of the “continuous-stirred tank reactor (CSTR) model” and the validation of this approach using rhodamine B dye as a surrogate for aerosolized microbial pathogens in a dynamic aerosol toroid (DAT). PMID:24082399

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

    NASA Technical Reports Server (NTRS)

    2008-01-01

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

  19. Spacecraft maximum allowable concentrations for selected airborne contaminants. Volume 2

    SciTech Connect

    1996-04-01

    The Subcommittee on Spacecraft Maximum Allowable Concentrations (SMAC) reviewed reports prepared by NASA scientists nd contractors recommending SMACs for approximately 35 spacecraft contaminants. The subcommittee sought to determine whether the SMAC reports were consistent with the 1992 guidelines. Appendix B of this volume contains the SMAC reports for 12 chemical contaminants that have been reviewed for their application of the guidelines developed in the first phase of this activity and approved by the subcommittee. This report is the second volume in the series.

  20. Health effects of airborne exposures from concentrated animal feeding operations.

    PubMed

    Heederik, Dick; Sigsgaard, Torben; Thorne, Peter S; Kline, Joel N; Avery, Rachel; Bønløkke, Jakob H; Chrischilles, Elizabeth A; Dosman, James A; Duchaine, Caroline; Kirkhorn, Steven R; Kulhankova, Katarina; Merchant, James A

    2007-02-01

    Toxic gases, vapors, and particles are emitted from concentrated animal feeding operations (CAFOs) into the general environment. These include ammonia, hydrogen sulfide, carbon dioxide, malodorous vapors, and particles contaminated with a wide range of microorganisms. Little is known about the health risks of exposure to these agents for people living in the surrounding areas. Malodor is one of the predominant concerns, and there is evidence that psychophysiologic changes may occur as a result of exposure to malodorous compounds. There is a paucity of data regarding community adverse health effects related to low-level gas and particulate emissions. Most information comes from studies among workers in CAFO installations. Research over the last decades has shown that microbial exposures, especially endotoxin exposure, are related to deleterious respiratory health effects, of which cross-shift lung function decline and accelerated decline over time are the most pronounced effects. Studies in naïve subjects and workers have shown respiratory inflammatory responses related to the microbial load. This working group, which was part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards-Searching for Solutions, concluded that there is a great need to evaluate health effects from exposures to the toxic gases, vapors, and particles emitted into the general environment by CAFOs. Research should focus not only on nuisance and odors but also on potential health effects from microbial exposures, concentrating on susceptible subgroups, especially asthmatic children and the elderly, since these exposures have been shown to be related to respiratory health effects among workers in CAFOs. PMID:17384782

  1. Health Effects of Airborne Exposures from Concentrated Animal Feeding Operations

    PubMed Central

    Heederik, Dick; Sigsgaard, Torben; Thorne, Peter S.; Kline, Joel N.; Avery, Rachel; Bønløkke, Jakob H.; Chrischilles, Elizabeth A.; Dosman, James A.; Duchaine, Caroline; Kirkhorn, Steven R.; Kulhankova, Katarina; Merchant, James A.

    2007-01-01

    Toxic gases, vapors, and particles are emitted from concentrated animal feeding operations (CAFOs) into the general environment. These include ammonia, hydrogen sulfide, carbon dioxide, malodorous vapors, and particles contaminated with a wide range of microorganisms. Little is known about the health risks of exposure to these agents for people living in the surrounding areas. Malodor is one of the predominant concerns, and there is evidence that psychophysiologic changes may occur as a result of exposure to malodorous compounds. There is a paucity of data regarding community adverse health effects related to low-level gas and particulate emissions. Most information comes from studies among workers in CAFO installations. Research over the last decades has shown that microbial exposures, especially endotoxin exposure, are related to deleterious respiratory health effects, of which cross-shift lung function decline and accelerated decline over time are the most pronounced effects. Studies in naïve subjects and workers have shown respiratory inflammatory responses related to the microbial load. This working group, which was part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards—Searching for Solutions, concluded that there is a great need to evaluate health effects from exposures to the toxic gases, vapors, and particles emitted into the general environment by CAFOs. Research should focus not only on nuisance and odors but also on potential health effects from microbial exposures, concentrating on susceptible subgroups, especially asthmatic children and the elderly, since these exposures have been shown to be related to respiratory health effects among workers in CAFOs. PMID:17384782

  2. Concentration and characterization of airborne particles in Tehran's subway system.

    PubMed

    Kamani, Hosein; Hoseini, Mohammad; Seyedsalehi, Mahdi; Mahdavi, Yousef; Jaafari, Jalil; Safari, Gholam Hosein

    2014-06-01

    Particulate matter is an important air pollutant, especially in closed environments like underground subway stations. In this study, a total of 13 elements were determined from PM10 and PM2.5 samples collected at two subway stations (Imam Khomeini and Sadeghiye) in Tehran's subway system. Sampling was conducted in April to August 2011 to measure PM concentrations in platform and adjacent outdoor air of the stations. In the Imam Khomeini station, the average concentrations of PM10 and PM2.5 were 94.4 ± 26.3 and 52.3 ± 16.5 μg m(-3) in the platform and 81.8 ± 22.2 and 35 ± 17.6 μg m(-3) in the outdoor air, respectively. In the Sadeghiye station, mean concentrations of PM10 and PM2.5 were 87.6 ± 23 and 41.3 ± 20.4 μg m(-3) in the platform and 73.9 ± 17.3 and 30 ± 15 μg m(-3), in the outdoor air, respectively. The relative contribution of elemental components in each particle fraction were accounted for 43% (PM10) and 47.7% (PM2.5) in platform of Imam Khomeini station and 15.9% (PM10) and 18.5% (PM2.5) in the outdoor air of this station. Also, at the Sadeghiye station, each fraction accounted for 31.6% (PM10) and 39.8% (PM2.5) in platform and was 11.7% (PM10) and 14.3% (PM2.5) in the outdoor. At the Imam Khomeini station, Fe was the predominant element to represent 32.4 and 36 % of the total mass of PM10 and PM2.5 in the platform and 11.5 and 13.3% in the outdoor, respectively. At the Sadeghiye station, this element represented 22.7 and 29.8% of total mass of PM10 and PM2.5 in the platform and 8.7 and 10.5% in the outdoor air, respectively. Other major crustal elements were 5.8% (PM10) and 5.3% (PM2.5) in the Imam Khomeini station platform and 2.3 and 2.4% in the outdoor air, respectively. The proportion of other minor elements was significantly lower, actually less than 7% in total samples, and V was the minor concentration in total mass of PM10 and PM2.5 in both platform stations. PMID:24573466

  3. Characterization of the airborne concentrations of lead in U. S. industry

    SciTech Connect

    Froines, J.R.; Baron, S.; Wegman, D.H.; O'Rourke, S. )

    1990-01-01

    Occupational exposure to lead represents a continuing problem of significant magnitude in the United States. To characterize the problem for surveillance purposes, an analysis of the airborne concentrations of lead identified in OSHA compliance inspections was conducted for the years 1979 to 1985. The five specific objectives of the study were: (1) to examine the distribution of air lead concentration in industrial environments; (2) to determine the secular trends in air lead concentrations for high lead industries; (3) to assess which job titles had excessive airborne lead concentrations; (4) to evaluate whether there was a relationship between lead overexposure and company size, unionization, or type of inspection; and (5) to investigate the prevalence of respirator violations for lead. Fifty-two industries were identified which had more than 1/3 of their inspection medians greater than the permissible exposure limit. These included primary and secondary lead smelting, battery manufacture, pigment manufacture, brass/bronze foundries, as well as 46 other industries. There has been little if any improvement in the prevalence and severity of airborne lead concentrations for the high lead industries, battery manufacture, secondary smelting, pigment manufacture, and brass/bronze foundries. Specific high exposure job titles are identified for certain high lead industries. The job title of painting stands out as an especially problematical job title across a number of industries. The prevalence of respirator violations is approximately 20% of all lead inspections.

  4. Concentration and Emission of Airborne Contaminants in a Laboratory Animal Facility Housing Rabbits

    PubMed Central

    Ooms, Tara G; Artwohl, James E; Conroy, Lorraine M; Schoonover, Todd M; Fortman, Jeffrey D

    2008-01-01

    Characterization of animal housing conditions can determine the frequency of bedding and cage changes, which are not standardized from facility to facility. Rabbits produce noticeable odors, and their excreta can scald and stain cages. Our facility wanted to document measurable airborne contaminants in a laboratory rabbit room in which excreta pans were changed weekly and cages changed biweekly. Contaminants included particulate, endotoxin, ammonia, carbon dioxide, and a rabbit salivary protein as a marker for rabbit allergen. Concentrations were measured daily over a 2-wk period in a laboratory animal facility to determine whether they increased over time and on days considered to be the dirtiest. Except for ammonia, concentrations of all airborne contaminants did not differ between clean and dirty days. Concentrations were lower than occupational health exposure guidelines for all contaminants studied, including ammonia. After measurement of concentration, a model was applied to calculate mean emission factors in this rabbit room. Examples of emission factor utilization to determine airborne contaminant concentration in rabbit rooms under various environmental conditions and housing densities are provided. PMID:18351721

  5. Environmental contamination of chrysotile asbestos and its toxic effects on antioxidative system of Lemna gibba.

    PubMed

    Trivedi, A K; Ahmad, I; Musthapa, M S; Ansari, F A

    2007-04-01

    Asbestos was monitored in various plant samples around an asbestos cement factory. Asbestos residue was found on the surface of all plant samples monitored. Based on asbestos concentration found in different plant samples during monitoring and on the property of asbestos to cause reactive oxygen species-mediated oxidative stress in animal models, laboratory experiments were conducted to assess the toxicity of chrysotile asbestos on an aquatic macrophyte, duckweed (Lemna gibba.). L. gibba plants were exposed to four concentrations (0.5, 1.0, 2.0, and 5.0 microg/mL) of chrysotile asbestos under laboratory conditions, and alterations in the glutathione and ascorbate antioxidative system were estimated at postexposure days 7, 14, 21, and 28 in order to assess changes in their level as suitable biomarkers of chrysotile contamination. Chrysotile exposure caused a decrease in total and reduced glutathione and an enhancement in the oxidized glutathione as well as the reduced/oxidized glutathione ratio. An increase in ascorbate pool size, and reduced as well as oxidized ascorbate was found to be accompanied by a decrease in the ratio of reduced/oxidized ascorbate. Alteration in the glutathione and ascorbate level might be considered as a biomarker of exposure to an unsafe environment because these are essential compounds of the general antioxidative strategy to overcome oxidative stress due to environmental constraints. Because an increase in the oxidation rate of antioxidants weakens cellular defenses and indicates a precarious state, they could constitute indicators of toxicity. PMID:17354032

  6. Sensitivity of airborne fluorosensor measurements to linear vertical gradients in chlorophyll concentration

    NASA Technical Reports Server (NTRS)

    Venable, D. D.; Punjabi, A. R.; Poole, L. R.

    1984-01-01

    A semianalytic Monte Carlo radiative transfer simulation model for airborne laser fluorosensors has been extended to investigate the effects of inhomogeneities in the vertical distribution of phytoplankton concentrations in clear seawater. Simulation results for linearly varying step concentrations of chlorophyll are presented. The results indicate that statistically significant differences can be seen under certain conditions in the water Raman-normalized fluorescence signals between nonhomogeneous and homogeneous cases. A statistical test has been used to establish ranges of surface concentrations and/or verticl gradients in which calibration by surface samples would by inappropriate, and the results are discussed.

  7. Device and method for accurately measuring concentrations of airborne transuranic isotopes

    DOEpatents

    McIsaac, Charles V.; Killian, E. Wayne; Grafwallner, Ervin G.; Kynaston, Ronnie L.; Johnson, Larry O.; Randolph, Peter D.

    1996-01-01

    An alpha continuous air monitor (CAM) with two silicon alpha detectors and three sample collection filters is described. This alpha CAM design provides continuous sampling and also measures the cumulative transuranic (TRU), i.e., plutonium and americium, activity on the filter, and thus provides a more accurate measurement of airborne TRU concentrations than can be accomplished using a single fixed sample collection filter and a single silicon alpha detector.

  8. Determining Airborne Concentrations of Spatial Repellent Chemicals in Mosquito Behavior Assay Systems

    PubMed Central

    Martin, Nicholas J.; Smith, Philip A.; Achee, Nicole L.; DeLong, Gerald T.

    2013-01-01

    Background Mosquito behavior assays have been used to evaluate the efficacy of vector control interventions to include spatial repellents (SR). Current analytical methods are not optimized to determine short duration concentrations of SR active ingredients (AI) in air spaces during entomological evaluations. The aim of this study was to expand on our previous research to further validate a novel air sampling method to detect and quantitate airborne concentrations of a SR under laboratory and field conditions. Methodology/Principal Findings A thermal desorption (TD) gas chromatography-mass spectrometry (GC-MS) method was used to determine the amount of dichlorodiphenyltrichloroethane (DDT) in samples of air. During laboratory experiments, 1 L volumes of air were collected over 10 min intervals from a three-chamber mosquito behavior assay system. Significantly higher levels of airborne DDT were measured in the chamber containing textiles treated with DDT compared to chambers free of AI. In the field, 57 samples of air were collected from experimental huts with and without DDT for onsite analysis. Airborne DDT was detected in samples collected from treated huts. The mean DDT air concentrations in these two huts over a period of four days with variable ambient temperature were 0.74 µg/m3 (n = 17; SD = 0.45) and 1.42 µg/m3 (n = 30; SD = 0.96). Conclusions/Significance The results from laboratory experiments confirmed that significantly different DDT exposure conditions existed in the three-chamber system establishing a chemical gradient to evaluate mosquito deterrency. The TD GC-MS method addresses a need to measure short-term (<1 h) SR concentrations in small volume (<100 L) samples of air and should be considered for standard evaluation of airborne AI levels in mosquito behavior assay systems. Future studies include the use of TD GC-MS to measure other semi-volatile vector control compounds. PMID:24015195

  9. Airborne crystalline silica concentrations at coal-fired power plants associated with coal fly ash.

    PubMed

    Hicks, Jeffrey; Yager, Janice

    2006-08-01

    This study presents measurements of airborne concentrations of respirable crystalline silica in the breathing zone of workers who were anticipated to encounter coal fly ash. Six plants were studied; two were fired with lignite coal, and the remaining four plants used bituminous and subbituminous coals. A total of 108 personal breathing zone respirable dust air samples were collected. Bulk samples were also collected from each plant site and subjected to crystalline silica analysis. Airborne dust particle size analysis was measured where fly ash was routinely encountered. The results from bituminous and subbituminous fired plants revealed that the highest airborne fly ash concentrations are encountered during maintenance activities: 0.008 mg/m3 to 96 mg/m3 (mean of 1.8 mg/m3). This group exceeded the threshold limit values (TLV) in 60% of the air samples. During normal production activities, airborne concentrations of crystalline silica ranged from nondetectable to 0.18 mg/m3 (mean value of 0.048 mg/m3). Air samples collected during these activities exceeded the current and proposed TLVs in approximately 54% and 65% of samples, respectively. Limited amounts of crystalline silica were detected in samples collected from lignite-fired plants, and approximately 20% of these air samples exceeded the current TLV. Particle size analysis in areas where breathing zone air samples were collected revealed mass median diameters typically between 3 microm and 8 microm. Bulk and air samples were analyzed for all of the common crystalline silica polymorphs, and only alpha quartz was detected. As compared with air samples, bulk samples from the same work areas consistently yielded lower relative amounts of quartz. Controls to limit coal fly ash exposures are indicated during some normal plant operations and during episodes of short term, but high concentrations of dust that may be encountered during maintenance activities, especially in areas where ash accumulations are present

  10. Device and method for accurately measuring concentrations of airborne transuranic isotopes

    DOEpatents

    McIsaac, C.V.; Killian, E.W.; Grafwallner, E.G.; Kynaston, R.L.; Johnson, L.O.; Randolph, P.D.

    1996-09-03

    An alpha continuous air monitor (CAM) with two silicon alpha detectors and three sample collection filters is described. This alpha CAM design provides continuous sampling and also measures the cumulative transuranic (TRU), i.e., plutonium and americium, activity on the filter, and thus provides a more accurate measurement of airborne TRU concentrations than can be accomplished using a single fixed sample collection filter and a single silicon alpha detector. 7 figs.

  11. Comparative hazards of chrysotile asbestos and its substitutes: A European perspective.

    PubMed

    Harrison, P T; Levy, L S; Patrick, G; Pigott, G H; Smith, L L

    1999-08-01

    Although the use of amphibole asbestos (crocidolite and amosite) has been banned in most European countries because of its known effects on the lung and pleura, chrysotile asbestos remains in use in a number of widely used products, notably asbestos cement and friction linings in vehicle brakes and clutches. A ban on chrysotile throughout the European Union for these remaining applications is currently under consideration, but this requires confidence in the safety of substitute materials. The main substitutes for the residual uses of chrysotile are p-aramid, polyvinyl alcohol (PVA), and cellulose fibers, and it is these materials that are evaluated here. Because it critically affects both exposure concentrations and deposition in the lung, diameter is a key determinant of the intrinsic hazard of a fiber; the propensity of a material to release fibers into the air is also important. It is generally accepted that to be pathogenic to the lung or pleura, fibers must be long, thin, and durable; fiber chemistry may also be significant. These basic principles are used in a pragmatic way to form a judgement on the relative safety of the substitute materials, taking into account what is known about their hazardous properties and also the potential for uncontrolled exposures during a lifetime of use (including disposal). We conclude that chrysotile asbestos is intrinsically more hazardous than p-aramid, PVA, or cellulose fibers and that its continued use in asbestos-cement products and friction materials is not justifiable in the face of available technically adequate substitutes. PMID:10417355

  12. [The airborne 1,3-butadiene concentrations in rubber and plastic processing plants].

    PubMed

    Yoshida, Toshiaki; Tainaka, Hidetsugu; Matsunaga, Ichiro; Goto, Sumio

    2002-03-01

    Environment pollution by 1,3-butadiene had considerably increased in Japan. The main cause of the pollution is the automotive exhaust gas, and leaks from factories, smoking, and burning of rubber and plastic products are considered to be minor sources. The object of this study was to determine the contamination levels of airborne 1,3-butadiene in factories processing rubber and plastics containing 1,3-butadiene. The concentrations of airborne 1,3-butadiene were measured in 21 plants (10 rubber processing plants and 11 plastics processing plants) in Osaka. 1,3-Butadiene in air was collected for 10 minutes with a charcoal tube and a portable small pump adjusted to a 250 ml/min flow rate. In each plant, indoor air samples at five points and an outdoor air sample at one point outside the plant were collected. The samples were subjected to gas chromatography/mass spectrometry after thermal desorption from the charcoal. The concentrations of airborne 1,3-butadiene in the rubber processing plants and the plastics processing plants were 0.14-2.20 micrograms/m3 (geometric mean: 0.48 microgram/m3) and 0.23-4.51 micrograms/m3 (geometric mean: 0.80 microgram/m3), respectively. In all plants examined, indoor 1,3-butadiene concentrations were higher than the outdoor concentrations around the plants. Therefore, 1,3-butadiene was considered to arise from the processing of rubber or plastics, but the indoor 1,3-butadiene concentrations were much lower than the PEL-TWA (1 ppm = 2.21 mg/m3) of OSHA and the TLV-TWA (2 ppm) of ACGIH. The concentrations in the plants with closed room conditions without ventilation were higher than the concentrations in the other plants. It was suggested that ventilation affected the 1,3-butadiene concentration in the plants. PMID:11993233

  13. Chrysotile asbestos exposure in the manufacturing of thermal insulating boards.

    PubMed

    Bhagia, L J; Vyas, J B; Shaikh, M I; Dodia, S L

    2010-08-01

    Exposure to asbestos fibers has been extensively studied in milling, mining of asbestos fibers, and in industries manufacturing asbestos-cement sheets, pipes, etc. However, very few studies have been reported in asbestos textiles, brake lining workers, and insulation products. In the present investigation, chrysotile exposure monitoring was carried out in a small thermal insulating boards manufacturing facility. Twenty-eight samples were analyzed from various locations like feeding of raw materials, weighing, pressing, machine grinding, and hand finishing of final products. Twenty-five percent of the samples were found to be above ACGIH TLV of 0.1 fibers per milliliter. However, mean fiber concentrations were found to be lower than 0.1 fibers per milliliter, except for the process of feeding of raw materials where the mean fiber concentration was 0.1087+/-0.0631 fibers per milliliter. PMID:19626449

  14. Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building.

    PubMed

    Oberle, Michael; Reichmuth, Markus; Laffer, Reto; Ottiger, Cornelia; Fankhauser, Hans; Bregenzer, Thomas

    2015-11-01

    Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m³ (inter-quartile range = IQR 1-4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m³ (IQR 26-126) in summer and 9 spores/m³ (IQR 6-15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m³). This variability may explain the variability of study results in the literature. PMID:26516890

  15. Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building

    PubMed Central

    Oberle, Michael; Reichmuth, Markus; Laffer, Reto; Ottiger, Cornelia; Fankhauser, Hans; Bregenzer, Thomas

    2015-01-01

    Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m3 (inter-quartile range = IQR 1–4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m3 (IQR 26–126) in summer and 9 spores/m3 (IQR 6–15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m3). This variability may explain the variability of study results in the literature. PMID:26516890

  16. Airborne crystalline silica concentrations at coal-fired power plants associated with coal fly ash

    SciTech Connect

    Hicks, J.; Yager, J.

    2006-08-15

    This study presents measurements of airborne concentrations of respirable crystalline silica in the breathing zone of workers who were anticipated to encounter coal fly ash. Six plants were studied; two were fired with lignite coal, and the remaining four plants used bituminous and subbituminous coals. A total of 108 personal breathing zone respirable dust air samples were collected. Bulk samples were also collected from each plant site and subjected to crystalline silica analysis. Airborne dust particle size analysis was measured where fly ash was routinely encountered. The results from bituminous and subbituminous fired plants revealed that the highest airborne fly ash concentrations are encountered during maintenance activities: 0.008 mg/m{sup 3} to 96 mg/m{sup 3} (mean of 1.8 mg/m{sup 3}). This group exceeded the threshold limit values (TLV) in 60% of the air samples. During normal production activities, airborne concentrations of crystalline silica ranged from nondetectable to 0.18 mg/m{sup 3} (mean value of 0.048 mg/m{sup 3}). Air samples collected during these activities exceeded the current and proposed TLVs in approximately 54% and 65% of samples, respectively. Limited amounts of crystalline silica were detected in samples collected from lignite-fired plants, and approximately 20% of these air samples exceeded the current TLV. Particle size analysis in areas where breathing zone air samples were collected revealed mass median diameters typically between 3 {mu}m and 8 {mu}m. Bulk and air samples were analyzed for all of the common crystalline silica polymorphs, and only alpha quartz was detected.

  17. Setting Spacecraft Maximum Allowable Concentrations for 1 hour or 24 hour contingency exposures to airborne chemicals

    NASA Technical Reports Server (NTRS)

    Garcia, Hector D.; Limero, Thomas F.; James, John T.

    1992-01-01

    Since the early years of the manned space program, NASA has developed and used exposure limits called Spacecraft Maximum Allowable Concentrations (SMACs) to help protect astronauts from airborne toxicants. Most of these SMACS are based on an exposure duration of 7 days, since this is the duration of a 'typical' mission. A set of 'contingency SMACs' is also being developed for scenarios involving brief (1-hour or 24- hour) exposures to relatively high levels of airborne toxicants from event-related 'contingency' releases of contaminants. The emergency nature of contingency exposures dictates the use of different criteria for setting exposure limits. The NASA JSC Toxicology Group recently began a program to document the rationales used to set new SMACs and plans to review the older, 7-day SMACs. In cooperation with the National Research Council's Committee on Toxicology, a standard procedure has been developed for researching, setting, and documenting SMAC values.

  18. Airborne concentrations of benzene associated with the historical use of some formulations of liquid wrench.

    PubMed

    Williams, Pamela R D; Knutsen, Jeffrey S; Atkinson, Chris; Madl, Amy K; Paustenbach, Dennis J

    2007-08-01

    The current study characterizes potential inhalation exposures to benzene associated with the historical use of some formulations of Liquid Wrench under specific test conditions. This product is a multiuse penetrant and lubricant commonly used in a variety of consumer and industrial settings. The study entailed the remanufacturing of several product formulations to have similar physical and chemical properties to most nonaerosol Liquid Wrench formulations between 1960 and 1978. The airborne concentrations of benzene and other constituents during the simulated application of these products were measured under a range of conditions. Nearly 200 breathing zone and area bystander air samples were collected during 11 different product use scenarios. Depending on the tests performed, average airborne concentrations of benzene ranged from approximately 0.2-9.9 mg/m(3) (0.08-3.8 ppm) for the 15-min personal samples; 0.1-8 mg/m(3) (0.04-3 ppm) for the 1-hr personal samples; and 0.1-5.1 mg/m(3) (0.04-2 ppm) for the 1-hr area samples. The 1-hr personal samples encompassed two 15-min product applications and two 15-min periods of standing within 5 to 10 feet of the work area. The measured airborne concentrations of benzene varied significantly based on the benzene content of the formulation tested (1%, 3%, 14%, or 30% v/v benzene) and the indoor air exchange rate but did not vary much with the base formulation of the product or the two quantities of Liquid Wrench used. The airborne concentrations of five other volatile chemicals (ethylbenzene, toluene, total xylenes, cyclohexane, and hexane) were also measured, and the results were consistent with the volatility and concentrations of these chemicals in the product tested. A linear regression analysis of air concentration compared with the chemical mole fraction in the solution and air exchange rate provided a relatively good fit to the data. The results of this study should be useful for evaluating potential inhalation

  19. Crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Sommer, J.; Frederiksen, L.; Gosewinkel Karlson, U.

    2012-06-01

    This study tests the hypothesis that Danish agricultural areas are the main source to airborne Alternaria spores in Copenhagen, Denmark. We suggest that the source to the overall load is mainly local, but with intermittent Long Distance Transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models.

  20. Ambient airborne-solids concentrations including volcanic ash at Hanford, Washington sampling sites subsequent to the Mount St. Helens eruption

    SciTech Connect

    Sehmel, G.A.

    1981-06-01

    A major eruption of Mount St. Helens, state of Washington, USA, occurred on May 18, 1980. The resulting volcanic ash plume was transported to the east. The Hanford area, northwest of Richland, Washington, was within the southern edge of the fallout plume. Airborne solid concentrations and airborne particle size distributions were measured at two sites in the Hanford area, a southern and northern site. During the initial sampling day (May 19), the average concentration for respirable particles, < 5.5-..mu..m diameter, was 1430-..mu..g/m/sup 3/ at the southern site; the total collection was 2610-..mu..g/m/sup 3/. The respirable content of the total airborne solids was 55%. At both sites average airborne solid concentrations decreased to 10- to 20-..mu..g/m/sup 3/ in December.

  1. Chrysotile asbestos quantification in serpentinite quarries: a case study in Valmalenco, central Alps, northern Italy

    NASA Astrophysics Data System (ADS)

    Cavallo, Alessandro

    2013-04-01

    Outcrops of serpentinites are usually strongly fractured and cataclastic, and the rock can only be used as ballast. However, in rare cases, like in Valmalenco (Central Alps, Northern Italy), fractures are regular and well spaced, and the rock mass has good geotechnical quality, ideal conditions for the extraction of dimension stone blocks. The Valmalenco Serpentinite is marketed worldwide as dimension and decorative stone, with remarkable mechanical properties and pleasing colours and textures. However, the same area was once subject to chrysotile asbestos mining, in the form of discrete veins along the main discontinuities of the rock mass. For this reason, airborne asbestos contamination can occur during the extraction and processing cycle of the rocks, therefore it is essential to locate and quantify asbestos in the rock mass, to reduce as much as possible the exposure risk. The first step was a detailed geostructural survey of each quarry, in order to characterize the main discontinuities (orientation, spacing, linear persistence, opening, filling), with special attention to the identification of fibrous minerals. The surveys was followed by extensive sampling of massive rocks, mineralized veins and fillings of fractures, and the cutting sludge derived from diamond wire cutting. Preliminary qualitative XRPD was performed on all samples, while quantitative analysis was carried out on the most representative samples of the main rock mass discontinuities. On the other hand, XRPD is not effective in the identification of asbestos percentages of less than 2% by weight, and the accurate distinction among the various serpentine polymorphs (antigorite, lizardite, chrysotile) is very difficult (if not impossible) when they are simultaneously present, due to their very similar basic structure and the strong structural disorder. The same samples were then analyzed by SEM-EDS (fiber counting after filtration on a polycarbonate filter), for a better distinction between

  2. Relating urban airborne particle concentrations to shipping using carbon based elemental emission ratios

    NASA Astrophysics Data System (ADS)

    Johnson, Graham R.; Juwono, Alamsyah M.; Friend, Adrian J.; Cheung, Hing-Cho; Stelcer, Eduard; Cohen, David; Ayoko, Godwin A.; Morawska, Lidia

    2014-10-01

    This study demonstrates a novel method for testing the hypothesis that variations in primary and secondary particle number concentration (PNC) in urban air are related to residual fuel oil combustion at a coastal port lying 30 km upwind, by examining the correlation between PNC and airborne particle composition signatures chosen for their sensitivity to the elemental contaminants present in residual fuel oil. Residual fuel oil combustion indicators were chosen by comparing the sensitivity of a range of concentration ratios to airborne emissions originating from the port. The most responsive were combinations of vanadium and sulphur concentration ([S], [V]) expressed as ratios with respect to black carbon concentration ([BC]). These correlated significantly with ship activity at the port and with the fraction of time during which the wind blew from the port. The average [V] when the wind was predominantly from the port was 0.52 ng m-3 (87%) higher than the average for all wind directions and 0.83 ng m-3 (280%) higher than that for the lowest vanadium yielding wind direction considered to approximate the natural background. Shipping was found to be the main source of V impacting urban air quality in Brisbane. However, contrary to the stated hypothesis, increases in PNC related measures did not correlate with ship emission indicators or ship traffic. Hence at this site ship emissions were not found to be a major contributor to PNC compared to other fossil fuel combustion sources such as road traffic, airport and refinery emissions.

  3. A literature review of concentrations and size distributions of ambient airborne Pb-containing particulate matter

    NASA Astrophysics Data System (ADS)

    Cho, Seung-Hyun; Richmond-Bryant, Jennifer; Thornburg, Jonathan; Portzer, Jeff; Vanderpool, Robert; Cavender, Kevin; Rice, Joann

    2011-09-01

    The final 2008 lead (Pb) national ambient air quality standards (NAAQS) revision maintains Pb in total suspended particulate matter as the indicator. However, the final rule permits the use of low-volume PM 10 (particulate matter sampled with a 50% cut-point of 10 μm) Federal Reference Method (FRM) monitors in lieu of total suspended particulate (TSP) monitors for some non-source-oriented monitoring. PM 10 FRM monitors are known to provide more reliable concentration measurements than TSP samplers because they are omni-directional samplers and so are not biased by wind conditions. However, by design they exclude the upper tail of the particle size distribution. Hence, each monitor produces uncertainties about measured concentrations of Pb-bearing PM. Uncertainties in reported Pb data are also related to spatiotemporal variation of the concentration and size distribution of Pb-bearing PM. Therefore, a comprehensive literature review was performed to summarize the current knowledge regarding the concentration and size distribution of Pb particles in the atmosphere. The objectives of this review were to compile data that could shed light on these uncertainties, to provide insights useful during future Pb NAAQS reviews, and to identify areas where more research is needed. Results of this review indicated that Pb size distribution data are relatively limited and often outdated. Thirty-nine articles were found to have sufficiently detailed information regarding airborne Pb concentrations, study location, sample collection methods, and analytical techniques; only 16 of those papers reported Pb concentration data for multiple size fractions. For the most part, U.S. and European studies from the last forty years illustrate that the largest mode of the size distribution of airborne particle-bound Pb has shifted to larger sizes while airborne Pb concentrations have decreased in urban areas. This shift occurred as tetraethyl Pb additives in gasoline were phased out and

  4. Decomposition of chrysotile asbestos by fluorosulfonic acid

    SciTech Connect

    Sugama, T.; Sabatini, R.; Petrakis, L.

    1998-01-01

    The effect of a fluorosulfonic acid (FSO{sub 3}H) aqueous solution on decomposing the chrysotile asbestos fibers was investigated by using FT-IR, XRD, and XPS. From the equilibrium of FSO{sub 3}H in an aqueous medium (FSO{sub 3}H + H{sub 2}O = HF + H{sub 2}SO{sub 4}), the resulting H{sub 2}SO{sub 4} had a strong affinity for the external Mg(OH){sub 2} layers in the tubular, scroll-like chrysotile structure. This acid-base reaction led to the precipitation and lixiviation of MgSO{sub 4}{center_dot}H{sub 2}O, MgO, and Mg{sup 2+} ion. Once the breakage of the outer Mg(OH){sub 2} layers occurred, HF readily diffused into the inner silicious layers and then reacted with silicates, converting them into SiO{sub 2} hydrate and H{sub 2}SiF{sub 6}, while the ionic reaction between lixiviated Mg{sup 2+} and F{sup {minus}} resulted in precipitating MgF{sub 2}, thereby destroying the fibrous nature of the asbestos. An optimum combination of HF and H{sub 2}SO{sub 4} contributed significantly to enhancing the rate of conversion of asbestos into nonfibrous materials in a short treatment time without any physical agitation.

  5. Concentrations and Sources of Airborne Particles in a Neonatal Intensive Care Unit.

    PubMed

    Licina, Dusan; Bhangar, Seema; Brooks, Brandon; Baker, Robyn; Firek, Brian; Tang, Xiaochen; Morowitz, Michael J; Banfield, Jillian F; Nazaroff, William W

    2016-01-01

    Premature infants in neonatal intensive care units (NICUs) have underdeveloped immune systems, making them susceptible to adverse health consequences from air pollutant exposure. Little is known about the sources of indoor airborne particles that contribute to the exposure of premature infants in the NICU environment. In this study, we monitored the spatial and temporal variations of airborne particulate matter concentrations along with other indoor environmental parameters and human occupancy. The experiments were conducted over one year in a private-style NICU. The NICU was served by a central heating, ventilation and air-conditioning (HVAC) system equipped with an economizer and a high-efficiency particle filtration system. The following parameters were measured continuously during weekdays with 1-min resolution: particles larger than 0.3 μm resolved into 6 size groups, CO2 level, dry-bulb temperature and relative humidity, and presence or absence of occupants. Altogether, over sixteen periods of a few weeks each, measurements were conducted in rooms occupied with premature infants. In parallel, a second monitoring station was operated in a nearby hallway or at the local nurses' station. The monitoring data suggest a strong link between indoor particle concentrations and human occupancy. Detected particle peaks from occupancy were clearly discernible among larger particles and imperceptible for submicron (0.3-1 μm) particles. The mean indoor particle mass concentrations averaged across the size range 0.3-10 μm during occupied periods was 1.9 μg/m3, approximately 2.5 times the concentration during unoccupied periods (0.8 μg/m3). Contributions of within-room emissions to total PM10 mass in the baby rooms averaged 37-81%. Near-room indoor emissions and outdoor sources contributed 18-59% and 1-5%, respectively. Airborne particle levels in the size range 1-10 μm showed strong dependence on human activities, indicating the importance of indoor

  6. Concentrations and Sources of Airborne Particles in a Neonatal Intensive Care Unit

    PubMed Central

    Licina, Dusan; Bhangar, Seema; Brooks, Brandon; Baker, Robyn; Firek, Brian; Tang, Xiaochen; Morowitz, Michael J.; Banfield, Jillian F.; Nazaroff, William W.

    2016-01-01

    Premature infants in neonatal intensive care units (NICUs) have underdeveloped immune systems, making them susceptible to adverse health consequences from air pollutant exposure. Little is known about the sources of indoor airborne particles that contribute to the exposure of premature infants in the NICU environment. In this study, we monitored the spatial and temporal variations of airborne particulate matter concentrations along with other indoor environmental parameters and human occupancy. The experiments were conducted over one year in a private-style NICU. The NICU was served by a central heating, ventilation and air-conditioning (HVAC) system equipped with an economizer and a high-efficiency particle filtration system. The following parameters were measured continuously during weekdays with 1-min resolution: particles larger than 0.3 μm resolved into 6 size groups, CO2 level, dry-bulb temperature and relative humidity, and presence or absence of occupants. Altogether, over sixteen periods of a few weeks each, measurements were conducted in rooms occupied with premature infants. In parallel, a second monitoring station was operated in a nearby hallway or at the local nurses’ station. The monitoring data suggest a strong link between indoor particle concentrations and human occupancy. Detected particle peaks from occupancy were clearly discernible among larger particles and imperceptible for submicron (0.3–1 μm) particles. The mean indoor particle mass concentrations averaged across the size range 0.3–10 μm during occupied periods was 1.9 μg/m3, approximately 2.5 times the concentration during unoccupied periods (0.8 μg/m3). Contributions of within-room emissions to total PM10 mass in the baby rooms averaged 37–81%. Near-room indoor emissions and outdoor sources contributed 18–59% and 1–5%, respectively. Airborne particle levels in the size range 1–10 μm showed strong dependence on human activities, indicating the importance of indoor

  7. Platinum and rhodium concentrations in airborne particulate matter in Germany from 1988 to 1998.

    PubMed

    Zereini, F; Wiseman, C; Alt, F; Messerschmidt, J; Müller, J; Urban, H

    2001-05-15

    Increases in platinum group element (PGE) concentrations in ambient air and dust since the introduction of automotive catalytic converters in 1988 is a cause of concern. Until now, data derived from engine-test bench experiments have provided the basis for the assessment of human health risks associated with PGE exposure. Such experiments have provided valuable information regarding emission data that has been used to estimate ambient exposure concentrations. However, these data are not necessarily representative of typical environmental PGE exposure levels and conditions. Data on measured environmental concentrations is needed to provide a more adequate basis for the assessment of exposure and related risks. Twenty air and airborne-dust samples were provided by the Umweltbundesamt (Federal Environmental Agency, Germany) in the years 1988, 1989, 1992, 1997, and 1998. The samples were collected in Frankfurt/Main and the adjacent city of Offenbach. For this, 11 to 80 m3 of air were filtered over a 24-72 h period using a vacuum. Glass-fiber filters were used to collect samples. Sample platinum and rhodium concentrations were determined using adsorptive voltammetry. Although the number of samples collected in different years is limited, the results indicate a trend toward continuous increases in ambient concentrations of these metals between 1988 and 1998. Specifically, there were 46- and 27-fold increases in Pt and Rh concentrations, respectively. Despite these observed increases, the Pt concentrations measured (i.e., 147 pg/m3 on average, with a maximum of 246 pg/m3 in 1998) fell far below 15,000 pg/m3, which has been suggested as a guidance value (i.e., exposure at this level would be expected to be without appreciable health risk). The results of a particle-size distribution analysis of one sample (8-step impactor) that was collected 150 m away from a street show that approximately 75% of Pt and 95% of Rh occurs in association with large particulate matter of > 2

  8. Magnetometric evaluation for the effect of chrysotile on alveolar macrophages.

    PubMed

    Keira, T; Okada, M; Katagiri, H; Aizawa, Y; Okayasu, I; Kotani, M

    1998-10-01

    Alveolar macrophages are thought to play an important role in fibrogenesis due to asbestos exposure. In this experiment, we evaluated the effect mainly by unique magnetometry and also by conventional methods such as lactate dehydrogenase (LDH) activity measurement and morphological observations. Alveolar macrophages obtained from Syrian golden hamsters by bronchoalveolar lavages were exposed 18 hours in vitro to Fe3O4 as an indicator for magnetometry and chrysotile for experiments. A rapid decrease of the remanent magnetic field, so called "relaxation", was observed after the cessation of an external magnetic field in macrophages phagocytizing Fe3O4 alone, while relaxation was delayed in those concurrently exposed to chrysotile. Since relaxation is thought due to the cytoskeleton-driven random rotation of phagosomes containing iron oxide particles, chrysotile is considered to interfere with the cytoskeletal function of macrophages. Release of LDH from chrysotile-exposed macrophages into the medium was recognized, but it was not significantly higher than the controls. Apoptosis was negligible in macrophages exposed to chrysotile by the DNA ladder detection, the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling method and morphological observations. Electron microscopical examinations revealed early necrotic changes in macrophages exposed to chrysotile. These findings indicate that cell magnetometry detects impaired cytoskeletal function due to in vitro exposure to chrysotile. PMID:10223613

  9. Inactivation of Airborne Bacteria and Viruses Using Extremely Low Concentrations of Chlorine Dioxide Gas.

    PubMed

    Ogata, Norio; Sakasegawa, Miyusse; Miura, Takanori; Shibata, Takashi; Takigawa, Yasuhiro; Taura, Kouichi; Taguchi, Kazuhiko; Matsubara, Kazuki; Nakahara, Kouichi; Kato, Daisuke; Sogawa, Koushirou; Oka, Hiroshi

    2016-01-01

    Infectious airborne microbes, including many pathological microbes that cause respiratory infections, are commonly found in medical facilities and constitute a serious threat to human health. Thus, an effective method for reducing the number of microbes floating in the air will aid in the minimization of the incidence of respiratory infectious diseases. Here, we demonstrate that chlorine dioxide (ClO2) gas at extremely low concentrations, which has no detrimental effects on human health, elicits a strong effect to inactivate bacteria and viruses and significantly reduces the number of viable airborne microbes in a hospital operating room. In one set of experiments, a suspension of Staphylococcus aureus, bacteriophage MS2, and bacteriophage ΦX174 were released into an exposure chamber. When ClO2 gas at 0.01 or 0.02 parts per million (ppm, volume/volume) was present in the chamber, the numbers of surviving microbes in the air were markedly reduced after 120 min. The reductions were markedly greater than the natural reductions of the microbes in the chamber. In another experiment, the numbers of viable airborne bacteria in the operating room of a hospital collected over a 24-hour period in the presence or absence of 0.03 ppm ClO2 gas were found to be 10.9 ± 6.7 and 66.8 ± 31.2 colony-forming units/m3 (n = 9, p < 0.001), respectively. Taken together, we conclude that ClO2 gas at extremely low concentrations (≤0.03 ppm) can reduce the number of viable microbes floating in the air in a room. These results strongly support the potential use of ClO2 gas at a non-toxic level to reduce infections caused by the inhalation of pathogenic microbes in nursing homes and medical facilities. PMID:26926704

  10. Performance of photocatalytic lamps on reduction of culturable airborne microorganism concentration.

    PubMed

    Chuaybamroong, Paradee; Thunyasirinon, Chuleewan; Supothina, Sitthisuntorn; Sribenjalux, Pipat; Wu, Chang-Yu

    2011-04-01

    Reduction of viable airborne Staphylococcus epidermidis and Aspergillus niger spore concentrations using two types of photocatalytic fluorescent lamps under controlled environmental conditions (25 vs. 35°C and 55 vs. 75% relative humidity) were investigated. Visible white-light and UVA black light were in-house spray-coated with TiO(2) and then compared with a commercially coated visible white-light for microbial concentration reduction. The white-light photocatalytic lamps reduced the concentration of culturable S. epidermidis up to 92% independent of temperature or humidity change, while the black light photocatalytic lamps completely inactivated the culturable bacteria at 25°C, 55% relative humidity. Humidity seemed to alleviate UVA damage since better bacteria survival was found. For A. niger spores, rising humidity or temperature could lower their concentration or drop their culturabilities so that a difference between the natural decay and photocatalytic disinfection could not be distinguished. Reductions of total bacteria and total fungi concentrations using these lamps were also examined under uncontrolled environmental conditions in an office and a waste-storage room. It was found that photocatalytic lamps could reduce total culturable bacteria concentration from 9 to 97% and total culturable fungi concentration from 3 to 95% within irradiation time of 30-480 min, respectively. Insignificant difference in concentration reduction among these photocatalytic lamps was pronounced. PMID:21339001

  11. Diurnal variation in airborne pollen concentrations of the selected taxa in Zagreb, Croatia.

    PubMed

    Toth, Ivan; Peternel, Renata; Srnec, Lidija; Vojniković, Bozo

    2011-09-01

    The number of individuals allergic to plant pollen has recently been on a constant increase. The knowledge of diurnal distribution and abundance of allergenic pollen types, their patterns and response to source position and weather is useful to correlate hay fever symptoms with the presence of allergenic pollen in the atmosphere. The aim of this study was to determine diurnal distribution of total airborne pollen, pollen of particular allergenic taxa, possible variation in diurnal pollen distribution at measuring sites placed at different heights, and effect of some meteorological parameters on airborne pollen concentrations. A 7-day Hirst-type volumetric pollen trap was used for pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). Total pollen of all plant taxa (Ambrosia sp., Betula sp., Cupressaceae, Urticaceae, Poaceae, Quercus sp., Fraxinus sp., Alnus sp., Corylus sp., Populus sp., Pinus sp., Picea sp.) observed showed a regular diurnal distribution at both sampling sites in both study years, with a rise in the pollen concentration recorded after 4.00 a.m. and 6.00 a.m., respectively. The peak pollen concentration occurred between 12.00 a.m. and 4.00 p.m., and the lowest diurnal pollen concentrations were recorded overnight. About 50% of the 24-h pollen concentration were released to the atmosphere between 10.00 a.m. and 4.00 p.m. The timing and size of diurnal peaks were closely related to high temperature, low humidity and south-west maximum wind direction. PMID:22220402

  12. Preparation and evaluation of a chrysotile asbestos-containing standard material for validating x-ray diffractometric quantitation.

    PubMed

    Asahi, Tomoharu; Kobayashi, Shinji; Nakayama, Kenichi; Konya, Takayuki; Fujinawa, Go; Nakamura, Toshihiro

    2011-01-01

    A standard material containing chrysotile asbestos for the validation of x-ray diffractometric quantitation was developed using an asbestos-containing building material i.e., perlite board. The board as the base material was crushed, pulverized, and homogenized. The homogeneity of the powder of perlite board was estimated by analysis of variance. The diffraction intensity values of the crystalline phases and the concentrations of elements determined by x-ray diffractometry and x-ray fluorescence analysis were used for analysis of variance. There is no significant difference between the within-bottle variance and the between-bottle variance, indicating that the powdered perlite board was sufficiently homogenous. The concentration of chrysotile in the material was determined using two methods: an internal standard/x-ray diffractometry method and the x-ray diffractometry/Rietveld refinement. The concentration of chrysotile in the material was determined by an internal standard/x-ray diffractometry method and the material had a chrysotile concentration of 24.1 ± 0.2 mass%. PMID:22156250

  13. Lifetime carcinogenesis studies of chrysotile asbestos (CAS No. 12001-29-5) in syrian golden hamsters (feed studies). Technical report series

    SciTech Connect

    Not Available

    1990-07-01

    Carcinogenesis studies of short range (SR), intermediate range (IR) or intermediate range chrysotile asbestos in combination with the intestinal carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were conducted with male and female Syrian golden hamsters. Both forms of chrysotile asbestos were administered at a concentration of 1% in pelleted diet for the entire lifetime of the hamsters, starting with mothers of the test animals. Group sizes varied from 125 to 253. Starting at 6 weeks of age, male and female hamsters in the intermediate range chrysotile/DMH study were given oral doses of DMH (4 mg/kg) every other week for a total of 5 doses. There was no adverse effect on body weight gain or survival by either form of asbestos or by asbestos in combination with DMH. Under the conditions of these studies, neither short range chrysotile nor intermediate range chrysotile asbestos was carcinogenic when ingested at 1% levels in the diet by male and female Syrian golden hamsters. While there were increases in the rates of adrenal cortical adenomas in male and female hamsters exposed to intermediate range chrysotile asbestos compared with pooled control groups, these incidence rates were not different when compared with the concurrent control groups. Additionally, the biologic importance of adrenal tumors in the absence of target organ (gastrointestinal tract) neoplasia is questionable.

  14. Airborne particle concentration and meteorologic conditions associated with pneumonia incidence in feedlot cattle.

    PubMed

    MacVean, D W; Franzen, D K; Keefe, T J; Bennett, B W

    1986-12-01

    To elucidate the role of air quality on the occurrence of pneumonia in feedlot cattle, the following environmental values were measured at a feedlot: suspended particulates in 5 particle-size fractions, relative humidity, air temperature, and barometric pressure. Pneumonia incidence data were classified by the number of days the cattle had been at the feedlot (days on feed). The concentration of airborne particles, range of temperature, days on feed, and season of the year were associated with incidence of pneumonia in cattle. Pneumonia incidence rates were greatest both within 15 days of arrival at the feedlot and during the fall sampling periods. The incidence of pneumonia in the 16 to 30 days-on-feed group was closely associated with the concentration of particles 2.0 to 3.3 microns in diameter and the range of daily temperature when exposure occurred 15 days before the onset of disease in the fall and 10 days before in the spring. PMID:3800131

  15. Airborne particle concentration and meteorologic conditions associated with pneumonia incidence in feedlot cattle

    SciTech Connect

    MacVean, D.W.; Franzen, D.K.; Keefe, T.J.; Bennett, B.W.

    1986-12-01

    To elucidate the role of air quality on the occurrence of pneumonia in feedlot cattle, the following environmental values were measured at a feedlot: suspended particulates in 5 particle-size fractions, relative humidity, air temperature, and barometric pressure. Pneumonia incidence data were classified by the number of days the cattle had been at the feedlot (days on feed). The concentration of airborne particles, range of temperature, days on feed, and season of the year were associated with incidence of pneumonia in cattle. Pneumonia incidence rates were greatest both within 15 days of arrival at the feedlot and during the fall sampling periods. The incidence of pneumonia in the 16 to 30 days-on-feed group was closely associated with the concentration of particles 2.0 to 3.3 microns in diameter and the range of daily temperature when exposure occurred 15 days before the onset of disease in the fall and 10 days before in the spring.

  16. Short fiber tremolite free chrysotile mesothelioma cohort revealed.

    PubMed

    Egilman, David; Bird, Tess

    2016-03-01

    In 1995, Dell and Teta published a cohort mortality study of asbestos molding compound workers at a Union Carbide Corporation (UCC) plastics manufacturing plant in Bound Brook, New Jersey. They reported that the factory workers were exposed to "asbestos (mostly chrysotile)," implying that the asbestos used at the Bound Brook plant occasionally contained amphiboles. However, UCC statements and testimony from recent litigation indicate that the Bound Brook plant exclusively used short fiber chrysotile asbestos. These recent documents also point to lower exposures than those reported by Dell and Teta. This chrysotile-only cohort should be included in analyses of chrysotile potency. Am. J. Ind. Med. 59:196-199, 2016. © 2016 Wiley Periodicals, Inc. PMID:26725926

  17. Re-Creation of Historical Chrysotile-Containing Joint Compounds

    PubMed Central

    Brorby, G. P.; Sheehan, P. J.; Berman, D. W.; Greene, J. F.; Holm, S. E.

    2008-01-01

    Chrysotile-containing joint compound was commonly used in construction of residential and commercial buildings through the mid 1970s; however, these products have not been manufactured in the United States for more than 30 years. Little is known about actual human exposures to chrysotile fibers that may have resulted from use of chrysotile-containing joint compounds, because few exposure and no health-effects studies have been conducted specifically with these products. Because limited amounts of historical joint compounds are available (and the stability or representativeness of aged products is suspect), it is currently impossible to conduct meaningful studies to better understand the nature and magnitude of potential exposures to chrysotile that may have been associated with historical use of these products. Therefore, to support specific exposure and toxicology research activities, two types of chrysotile-containing joint compounds were produced according to original formulations from the late 1960s. To the extent possible, ingredients were the same as those used originally, with many obtained from the original suppliers. The chrysotile used historically in these products was primarily Grade 7RF9 from the Philip Carey mine. Because this mine is closed, a suitable alternate was identified by comparing the sizes and mineral composition of asbestos structures in a sample of what has been represented to be historical joint compound (all of which were chrysotile) to those in samples of three currently commercially available Grade 7 chrysotile products. The re-created materials generally conformed to original product specifications (e.g. viscosity, workability, crack resistance), indicating that these materials are sufficiently representative of the original products to support research activities. PMID:18788019

  18. Comparative hazards of chrysotile asbestos and its substitutes: A European perspective.

    PubMed Central

    Harrison, P T; Levy, L S; Patrick, G; Pigott, G H; Smith, L L

    1999-01-01

    Although the use of amphibole asbestos (crocidolite and amosite) has been banned in most European countries because of its known effects on the lung and pleura, chrysotile asbestos remains in use in a number of widely used products, notably asbestos cement and friction linings in vehicle brakes and clutches. A ban on chrysotile throughout the European Union for these remaining applications is currently under consideration, but this requires confidence in the safety of substitute materials. The main substitutes for the residual uses of chrysotile are p-aramid, polyvinyl alcohol (PVA), and cellulose fibers, and it is these materials that are evaluated here. Because it critically affects both exposure concentrations and deposition in the lung, diameter is a key determinant of the intrinsic hazard of a fiber; the propensity of a material to release fibers into the air is also important. It is generally accepted that to be pathogenic to the lung or pleura, fibers must be long, thin, and durable; fiber chemistry may also be significant. These basic principles are used in a pragmatic way to form a judgement on the relative safety of the substitute materials, taking into account what is known about their hazardous properties and also the potential for uncontrolled exposures during a lifetime of use (including disposal). We conclude that chrysotile asbestos is intrinsically more hazardous than p-aramid, PVA, or cellulose fibers and that its continued use in asbestos-cement products and friction materials is not justifiable in the face of available technically adequate substitutes. Images Figure 1 PMID:10417355

  19. Solubility of chrysotile asbestos and basalt fibers in relation to their fibrogenic and carcinogenic action.

    PubMed Central

    Kogan, F M; Nikitina, O V

    1994-01-01

    Fiber length and persistence are thought to be determinants for the development of toxic, fibrogenic, and carcinogenic effects of fibrous dusts. When the solubilities of chrysotile asbestos (CA) and basalt fibers (BF) were compared by measuring the loss of silica and magnesium in Leineweber's solution, CA was shown to be the more soluble. In a 6-month inhalation experiment, chrysotile at a mean concentration of 25 mg/m3 had a higher clearance rate than other comparable dusts. In acute toxicity studies, chrysotile and basalt fibers were administered intraperitoneally. At a dose of 1.7 g/kg body weight of CA, one third of the animals died. A dose of 2.7 g/kg body weight killed all the animals. With BF, even at a dose of 10 g/kg body weight all the animals survived. When the two fibers were administered over a 6-month period, either intratracheally or by inhalation, fibrotic lesions were more common in the group that received CA. Intraperitoneal administration of CA led to three times as many deaths from peritoneal mesothelioma as administration of BF. It appears, therefore, that in spite of its higher solubility and lower persistence, CA was the more toxic, fibrogenic and carcinogenic fiber, which gives rise to the hypothesis that the surface chemistry of the fibers is the determinant for biological activity. PMID:7882932

  20. Relationship of airborne trimellitic anhydride concentrations to trimellitic anhydride--induced symptoms and immune responses

    SciTech Connect

    Bernstein, D.I.; Roach, D.E.; McGrath, K.G.; Larsen, R.S.; Zeiss, C.R.; Patterson, R.

    1983-12-01

    Eighteen workers exposed to trimellitic anhydride (TMA) powder were evaluated in 1979. Twelve of these workers were available for longitudinal study until 1982. Annual clinical evaluations and serum radioimmunoassays for total antibody binding and specific IgE binding to /sup 125/I-TM-HSA were performed. In 1979, five workers had antibody against TM-HSA. Of these, three workers were diagnosed with the late respiratory systemic syndrome (LRSS) and one worker with TMA-induced allergic rhinitis. The LRSS workers had significantly elevated total antibody binding of /sup 125/I-TM-HSA and the worker with rhinitis had significantly elevated specific IgE binding of /sup 125/I-TM-HSA per milliliter of serum. Although TMA handling was intermittent throughout the year, average airborne dust concentrations from 1974 to 1978 at job stations of the two heaviest TMA-exposed occupations, operator and assistant operator, were 2.1 and 0.82 mg/m3, respectively. After local exhaust ventilation had been improved, average airborne dust concentrations of TMA at the two latter job stations fell to levels of 0.03 and 0.01 mg/m3, respectively, in 1982. The decrease in TMA exposure coincided with a gradual fall in total antibody binding of /sup 125/I-TM-HSA per milliliter in 1982 and symptomatic improvement in the three individuals with the LRSS. The continuous low-level exposure of the worker with TMA rhinitis was sufficient to elicit a rise in specific IgE against TM-HSA from 1.1 ng of 125I-TM-HSA bound per milliliter in 1979 to 2.12 in 1982.

  1. Total element concentration and chemical fractionation in airborne particulate matter from Santiago, Chile

    NASA Astrophysics Data System (ADS)

    Richter, Pablo; Griño, Paulina; Ahumada, Inés; Giordano, Ady

    Total element determination and chemical fractionation were carried out in airborne particulate matter (PM 10) from the Cerrillos monitoring station in Santiago, Chile, sampled in July (winter), 1997-2003. Element concentration in the period under study (1997-2003) was statistically analyzed through cluster analysis in order to identify groups of elements having similar behavior along time. Elements such as Cd, Cu, Pb, Ni, As and Mg show a clear decrease in concentration with time. On the contrary, chromium increases its concentration almost linearly during the period. In order to estimate whether the presence of a certain element in PM 10 matrix is mainly due to anthropogenic or natural processes, the enrichment factor of each element was determined. According to their behavior in the sequential extraction procedure, the elements were grouped by multivariate analysis in three clusters: (a) those mobile elements (Pb, Cd, Zn, Mn, Cu and As) which are weakly bound to the matrix (fractions 1 and 2) (b) those elements (V, Ti, and Cr) mainly bound to carbonates and oxides (fraction 3) and (c) the most immobile elements (Ni, Mo, Ca, Mg, Ba and Al), mainly bound to silicates and organic matter (fraction 4). A source of great concern is the fact that elements of such high toxicity as Pb, Cd and As are highly concentrated in both mobile fractions, indicating that these elements have a direct impact on the environment and on the health of the exposed population.

  2. Influence of urban climate upon distribution of airborne Deuteromycete spore concentrations in Mexico City

    NASA Astrophysics Data System (ADS)

    Calderón, C.; Lacey, J.; McCartney, A.; Rosas, I.

    The effect of an urban climate upon the spatial and temporal distribution of Deuteromycete spores was studied during 1991 using Burkard volumetric spore traps in two areas of Mexico City with different degrees of urbanization. Deuteromycete conidia formed the largest component of the total airborne fungal spore load in the atmosphere of Mexico City, contributing 52% of the spores trapped in an urban-residential area (southern area) and 65% of those in an urban-commercial area (central area). Among the most common spore types, Cladosporium and Alternaria showed a marked seasonal periodicity with significant differences in concentration (P<0.05) between the dry and wet seasons. Maximum conidial concentrations were found during the end of the wet season and the beginning of the cool, dry season (October-December). Daily mean concentrations of the predominant airborne spore types did not differ significantly between the southern and central areas. Daily mean spore concentrations were significantly correlated (P<0.05) in southern and central areas with maximum temperature (south, r = -0.35 central, r = -0.40) and relative humidity (south, r = 0.43; central, r = 0.29) from the previous day. Moreover, multiple regression analysis of spore concentrations with several meteorological factors showed significant interactions between fungal spores, relative humidity and maximum temperature in both areas. The diurnal periodicity of Cladosporium conidia characteristically showed two or three peaks in concentration during the day at 0200-0400, 1400 and 2000-2200 hours, while that of Alternaria showed only one peak (1200 to 2000 hours) in both areas. Maximum concentrations of these spores generally occurred 2-4 h earlier in the southern than in the central area. The lag in reaching maximum concentrations in the central area probably resulted from differences in the local conditions between the study areas, and from spores transported aerially into the city from distant sources. The

  3. Concentrations of particulate airborne polycyclic aromatic hydrocarbons and metals collected in Lahore, Pakistan

    NASA Astrophysics Data System (ADS)

    Smith, D. J. T.; Harrison, Roy M.; Luhana, L.; Pio, Casimiro A.; Castro, L. M.; Tariq, Mohammad Nawaz; Hayat, S.; Quraishi, T.

    Hi-vol air sampling equipment was run at three sites (representative of "city", "industrial" and "rural" sampling locations) in Lahore, Pakistan, for over a year. The extraction and quantitative analyses of all Lahore air samples was completed for a suite of metals, various anions, ammonium, elemental and organic carbon, as well as particle-associated polycyclic aromatic hydrocarbons (PAHs). A comparison of Lahore yearly mean pollutant concentrations with those obtained in Birmingham, U.K., shows that airborne metal levels in the Pakistani city are greater by at least one order of magnitude. The concentrations in Lahore obtained from this study are broadly in line with similar studies in Karachi as well as Calcutta and Bombay. Concentrations of particle-associated PAH are also around one order of magnitude higher than in U.K. samples, and, given the difference in ambient temperature, vapour-to-particle ratios of PAH are expected to be far higher in the hotter climate of Lahore. Minerals identified by X-ray diffraction (XRD) in the Lahore air samples were broadly in line with those determined at locations in other parts of the world.

  4. EVALUATION OF THREE CLEANING METHODS FOR REMOVING ASBESTOS FROM CARPET: DETERMINATION OF AIRBORNE ASBESTOS CONCENTRATIONS ASSOCIATED WITH EACH METHOD

    EPA Science Inventory

    This study was conducted to compare the effectiveness of three cleaning methods to remove asbestos from contaminated carpet and to determine the airborne asbestos concentrations associated with the use of each method. he carpet on which the methods were tested was naturally conta...

  5. EVALUATION OF THREE CLEANING METHODS FOR REMOVING ASBESTOS FROM CARPET. DETERMINATION OF AIRBORNE ASBESTOS CONCENTRATIONS ASSOCIATED WITH EACH METHOD

    EPA Science Inventory

    This study was conducted to compare the effectiveness of three cleaning methods to remove asbestos from contaminated carpet and to determine the airborne asbestos concentrations associated with the use of each method. The carpet on which the methods were tested was naturally cont...

  6. Ambient Airborne Solids Concentrations Including Volcanic Ash at Hanford, Washington Sampling Sites Subsequent to the Mount St. Helens Eruption

    SciTech Connect

    Sehmel, G.A.

    1982-12-20

    A major eruption of Mount St. Helens occurred on May 18, 1980. Subsequently, airborne solid concentrations were measured as a function of time at two sites within the southern edge of the fallout plume about 211 km east of Mount St. Helens. This ash was a source for investigating area-wide resuspension. Rain had a variable effect on decreasing airborne concentrations from resuspension. From 0.5 to 1.5 cm of rain were required to significantly reduce airborne solid concentrations through July. For a more aged resuspension source in September, a rain of 2.0 cm had a negligible effect. A monthly average threshold-wind speed for resuspension was defined as 3.6 m/s. For monthly-average wind speeds less than the threshold wind speed, monthly-average airborne concentrations tended to decrease with time. A decrease was recorded between September and October. For this 4-month time period, the half-life was on the order of 50 days, corresponding to a weathering rate of 5.1 year/sup -1/.

  7. Biodiversity and concentrations of airborne fungi in large US office buildings from the BASE study

    NASA Astrophysics Data System (ADS)

    Tsai, Feng C.; Macher, Janet M.; Hung, Yun-Yi

    The Building Assessment Survey and Evaluation (BASE) study measured baseline concentrations of airborne fungi in 100 representative US office buildings in 1994-1998. Multiple samples for different sampling durations, sites, and times of the day were aggregated into building-wide indoor and outdoor average concentrations. Fungal concentrations were compared between locations (indoor vs. outdoor), sampling and analytical methods (culture vs. microscopy), and season (summer vs. winter). The arithmetic means (standard deviations) of the indoor/outdoor concentrations of culturable fungi and fungal spores were 100/680 (230/840) CFUm-3 and 270/6540 (1190/6780) sporem-3, respectively. Although fewer groups were observed indoors than outdoors, at lower average concentrations (except in two buildings), site-specific and building-wide indoor measurements had higher coefficients of variation. More groups were seen in summer, and aggregated concentrations tended to be higher than in winter except for culturable Aureobasidium spp. and Botrytis spp. outdoors and non-sporulating fungi in both locations. Rankings of the predominant fungi identified by both methods were similar, but overall indoor and outdoor spore concentrations were approximately 3 and 10 times higher, respectively, than concentrations of culturable fungi. In the 44 buildings with both measurements, the indoor and outdoor total culturable fungi to fungal spore ratios (total C/S ratios) were 1.27 and 0.25, with opposite seasonal patterns. The indoor C/S ratio was higher in summer than in winter (1.47 vs. 0.86; N=29 and 15, respectively), but the outdoor ratio was lower in summer (0.19 vs. 0.36, respectively). Comparison of the number of different fungal groups and individual occurrence in buildings and samples indicated that the outdoor environment and summer season were more diverse, but the proportional contributions of the groups were very similar suggesting that the indoor and outdoor environments were related

  8. Measuring methane concentrations from anthropogenic and natural sources using airborne imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Thorpe, A. K.; Frankenberg, C.; Roberts, D. A.

    2013-12-01

    Two quantitative retrieval techniques were developed for measuring methane (CH4) enhancements for concentrated plumes using high spatial and moderate spectral resolution data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). An Iterative Maximum a Posteriori Differential Optical Absorption Spectroscopy (IMAP-DOAS) algorithm performed well for a homogenous ocean scene containing natural CH4 emissions from the Coal Oil Point (COP) seeps near Santa Barbara, California. A hybrid approach using Singular Value Decomposition (SVD) was particularly effective for terrestrial surfaces given it could better account for highly variable surface reflectance of complex urban environments. These techniques permitted mapping of a distinct plume at COP consistent with known seep locations and local wind direction, with maximum near surface enhancements of 2.85 ppm CH4 above background. At the Inglewood Oil Field, a CH4 plume was observed immediately downwind of two hydrocarbon storage tanks with a maximum concentration of 8.45 ppm above background. Results from a field campaign using the next generation sensor (AVIRISng) and controlled CH4 releases will also be discussed. AVIRIS-like sensors offer the potential to better constrain both CH4 and CO2 emissions on local and regional scales, including sources of increasing concern like industrial point source emissions and fugitive CH4 from the oil and gas industry. Fig. 1. CH4 plumes and measured enhancements for the COP seeps (top) and hydrocarbon storage tanks (bottom).

  9. Indicators of airborne fungal concentrations in urban homes: understanding the conditions that affect indoor fungal exposures.

    PubMed

    Crawford, Judith A; Rosenbaum, Paula F; Anagnost, Susan E; Hunt, Andrew; Abraham, Jerrold L

    2015-06-01

    Indoor fungal exposure can compromise respiratory health. Low-income urban areas are of concern because of high asthma and allergy rates and housing disrepair. Understanding the conditions that affect indoor fungal exposures is important for assessing health risks and for developing mitigation strategies. We examined the types and concentrations of airborne fungi inside and outside of homes in low-income areas of Syracuse, NY as well as the effect of snow cover on fungal levels. At 103 homes, air samples for viable fungi were collected, occupants were interviewed and homes were inspected for visible mold, musty odors, water problems and other factors. Multivariable logistic regression was used to relate high fungal levels to home conditions. Predominant indoor fungi included Cladosporium, Penicillium, Aspergillus, Alternaria and hyaline unknowns. Basidiomycetes and an uncommon genus Acrodontium were also found frequently due to analysis methods developed for this project. With snow cover, outdoor total fungal levels were depressed and indoor concentrations were three times higher than outdoor on average with a maximum of 29 times higher. Visible mold was related to elevated levels of Penicillium (OR 4.11 95% CI 1.37-14.0) and bacteria (OR 3.79 95% CI 1.41-11.2). Musty, moldy odors were associated with elevated concentrations of total fungi (OR 3.48 95% CI 1.13-11.6) and basidiomycetes. Cockroaches, an indicator of moisture, were associated with elevated levels of Penicillium (OR 3.66 95% CI 1.16-13.1) and Aspergillus (OR 4.36 95% CI 1.60-13.4). Increasing relative humidity was associated with higher concentrations of Penicillium, yeasts and basidiomycetes. Visible mold, musty odors, indoor humidity and cockroaches are modifiable factors that were important determinants of indoor fungal exposures. Indoor air investigators should interpret indoor:outdoor fungal ratios cautiously when snow cover is present. PMID:25725196

  10. Airborne Lidar Measurements of Atmospheric Column CO2 Concentration to Cloud Tops

    NASA Astrophysics Data System (ADS)

    Mao, J.; Ramanathan, A. K.; Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.

    2015-12-01

    Globally distributed atmospheric CO2 measurements with high precision, low bias and full seasonal sampling are crucial to advance carbon cycle sciences. However, two thirds of the Earth's surface is typically covered by clouds, and passive remote sensing approaches from space, e.g., OCO-2 and GOSAT, are limited to cloud-free scenes. They are unable to provide useful retrievals in cloudy areas where the photon path-length can't be well characterized. Thus, passive approaches have limited global coverage and poor sampling in cloudy regions, even though some cloudy regions have active carbon surface fluxes. NASA Goddard is developing a pulsed integrated-path, differential absorption (IPDA) lidar approach to measure atmospheric column CO2 concentrations from space as a candidate for NASA's ASCENDS mission. Measurements of time-resolved laser backscatter profiles from the atmosphere also allow this technique to estimate column CO2 and range to cloud tops in addition to those to the ground with precise knowledge of the photon path-length. This allows retrievals of column CO2 concentrations to cloud tops, providing much higher spatial coverage and some information about vertical structure of CO2. This is expected to benefit atmospheric transport process studies, carbon data assimilation in models, and global and regional carbon flux estimation. We show some preliminary results of the all-sky retrieval capability using airborne lidar measurements from the 2011, 2013 and 2014 ASCENDS airborne campaigns on the NASA DC-8. These show retrievals of atmospheric CO2 over low-level marine stratus clouds, cumulus clouds at the top of planetary boundary layer, some mid-level clouds and visually thin high-level cirrus clouds. The CO2 retrievals from the lidar are validated against in-situ measurements and compared to Goddard PCTM model simulations. Lidar cloud slicing to derive CO2 abundance in the planetary boundary layer and free troposphere also has been demonstrated. The

  11. Airborne Pollen Concentrations and Emergency Room Visits for Myocardial Infarction: A Multicity Case-Crossover Study in Ontario, Canada.

    PubMed

    Weichenthal, Scott; Lavigne, Eric; Villeneuve, Paul J; Reeves, François

    2016-04-01

    Few studies have examined the acute cardiovascular effects of airborne allergens. We conducted a case-crossover study to evaluate the relationship between airborne allergen concentrations and emergency room visits for myocardial infarction (MI) in Ontario, Canada. In total, 17,960 cases of MI were identified between the months of April and October during the years 2004-2011. Daily mean aeroallergen concentrations (pollen and mold spores) were assigned to case and control periods using central-site monitors in each city along with daily measurements of meteorological data and air pollution (nitrogen dioxide and ozone). Odds ratios and their 95% confidence intervals were estimated using conditional logistic regression models adjusting for time-varying covariates. Risk of MI was 5.5% higher (95% confidence interval (CI): 3.4, 7.6) on days in the highest tertile of total pollen concentrations compared with days in the lowest tertile, and a significant concentration-response trend was observed (P < 0.001). Higher MI risk was limited to same-day pollen concentrations, with the largest risks being observed during May (odds ratio = 1.16, 95% CI: 1.00, 1.35) and June (odds ratio = 1.10, 95% CI: 1.00, 1.22), when tree and grass pollen are most common. Mold spore concentrations were not associated with MI. Our findings suggest that airborne pollen might represent a previously unidentified environmental risk factor for myocardial infarction. PMID:26934896

  12. Airborne hyperspectral imaging for sensing phosphorus concentration in the Lake Okeechobee drainage basin

    NASA Astrophysics Data System (ADS)

    Bogrekci, Ismail; Lee, Won Suk; Jordan, Jonathan D.

    2005-05-01

    Eutrophication disturbs the ecological balance in the Lake Okeechobee due to high concentration of phosphorus emanated from the regions in the lake's drainage basin. Ability of measuring phosphorus (P) concentrations of water in the Lake Okeechobee itself is very important. Furthermore, monitoring P in its drainage basins is crucial in order to find the cause of P loading and contributing regions. Also, inexpensive real-time sensing capability for a large area in a short time would help scientist, government agents, and civilians to understand the causes, spot the high-risk areas, and develop management practices for restoring the natural equilibrium. In order to measure P concentrations in the Lake Okeechobee drainage basin, airborne hyperspectral images were taken from five representative target sites by deploying a modified queen air twin engine aircraft. Each flight line covered a swath of approximately 365 m wide. Spatial resolution was about 1 m. Spectral range covered was between 412.65 and 991.82 nm with an approximate of 5 nm spectral resolution. Ground truthing was conducted to collect soil and vegetation samples, GPS coordinates of each location, and reflectance measurement of each sample. On the ground, spectral reflectance was measured using a handheld spectrometer in 400-2500 nm. The samples were sent to a laboratory for chemical analysis. Also diffuse reflectance of the samples was measured in a laboratory setting using a spectrophotometer with an integrating sphere. Images were geocorrected and rectified to reduce geometric effect. Calibration of images was conducted to obtain actual reflectance of the target area. Score, SAM (Spectral Angle Mapping), SFF (Spectral Feature Fitting) were computed for spectral matching with image derived spectral library.

  13. Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

    NASA Astrophysics Data System (ADS)

    Bau, Sébastien; Witschger, Olivier; Gensdarmes, François; Thomas, Dominique

    2009-05-01

    An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP [1]. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak™ 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

  14. Apparatus and methods for monitoring the concentrations of hazardous airborne substances, especially lead

    DOEpatents

    Zaromb, Solomon

    2004-07-13

    Air is sampled at a rate in excess of 100 L/min, preferably at 200-300 L/min, so as to collect therefrom a substantial fraction, i.e., at least 20%, preferably 60-100%, of airborne particulates. A substance of interest (analyte), such as lead, is rapidly solubilized from the the collected particulates into a sample of liquid extractant, and the concentration of the analyte in the extractant sample is determined. The high-rate air sampling and particulate collection may be effected with a high-throughput filter cartridge or with a recently developed portable high-throughput liquid-absorption air sampler. Rapid solubilization of lead is achieved by a liquid extractant comprising 0.1-1 M of acetic acid or acetate, preferably at a pH of 5 or less and preferably with inclusion of 1-10% of hydrogen peroxide. Rapid determination of the lead content in the liquid extractant may be effected with a colorimetric or an electroanalytical analyzer.

  15. The coefficient of friction of chrysotile gouge at seismogenic depths

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, D.A.; Tanaka, H.; Iwata, K.

    2004-01-01

    We report new strength data for the serpentine mineral chrysotile at effective normal stresses, ??sn between 40 and 200 MPa in the temperature range 25??-280??C. Overall, the coefficient of friction, ?? (= shear stress/effective normal stress) of water-saturated chrysotile gouge increases both with increasing temperature and ??sn, but the rates vary and the temperature-related increases begin at ???100??C. As a result, a frictional strength minimum (?? = 0.1) occurs at low ??sn at about 100??C. Maximum strength (?? = 0.55) results from a combination of high normal stress and high temperature. The low-strength region is characterized by velocity strengthening and the high-strength region by velocity-weakening behavior. Thoroughly dried chrysotile has ?? = 0.7 and is velocity-weakening. The frictional properties of chrysolite can be explained in its tendency to adsorb large amounts of water that acts as a lubricant during shear. The water is progressively driven off the fiber surfaces with increasing temperature and pressure, causing chrysotile to approach its dry strength. Depth profiles for a chrysotile-lined fault constructed from these data would pass through a strength minimum at ???3 km depth, where sliding should be stable. Below that depth, strength increases rapidly as does the tendency for unstable (seismic) slip. Such a trend would not have been predicted from the room-temperature data. These results therefore illustrate the potential hazards of extrapolating room-temperature friction data to predict fault zone behavior at depth. This depth profile for chrysotile is consistent with the pattern of slip on the Hayward fault, which creeps aseismically at shallow depths but which may be locked below 5 km depth. ?? 2004 by V. H. Winston and Son, Inc. All rights reserved.

  16. Concentration, Size Distribution, and Infectivity of Airborne Particles Carrying Swine Viruses

    PubMed Central

    Alonso, Carmen; Raynor, Peter C.; Davies, Peter R.; Torremorell, Montserrat

    2015-01-01

    When pathogens become airborne, they travel associated with particles of different size and composition. Particle size determines the distance across which pathogens can be transported, as well as the site of deposition and the survivability of the pathogen. Despite the importance of this information, the size distribution of particles bearing viruses emitted by infectious animals remains unknown. In this study we characterized the concentration and size distribution of inhalable particles that transport influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSV), and porcine epidemic diarrhea virus (PEDV) generated by acutely infected pigs and assessed virus viability for each particle size range. Aerosols from experimentally infected pigs were sampled for 24 days using an Andersen cascade impactor able to separate particles by size (ranging from 0.4 to 10 micrometer (μm) in diameter). Air samples collected for the first 9, 20 and the last 3 days of the study were analyzed for IAV, PRRSV and PEDV, respectively, using quantitative reverse transcription polymerase chain reaction (RT-PCR) and quantified as geometric mean copies/m3 within each size range. IAV was detected in all particle size ranges in quantities ranging from 5.5x102 (in particles ranging from 1.1 to 2.1μm) to 4.3x105 RNA copies/m3 in the largest particles (9.0–10.0μm). PRRSV was detected in all size ranges except particles between 0.7 and 2.1μm in quantities ranging from 6x102 (0.4–0.7μm) to 5.1x104 RNA copies/m3 (9.0–10.0μm). PEDV, an enteric virus, was detected in all particle sizes and in higher quantities than IAV and PRRSV (p < 0.0001) ranging from 1.3x106 (0.4–0.7μm) to 3.5x108 RNA copies/m3 (9.0–10.0μm). Infectious status was demonstrated for the 3 viruses, and in the case of IAV and PRRSV, viruses were isolated from particles larger than 2.1μm. In summary, our results indicated that airborne PEDV, IAV and PRRSV can be found in a wide range of

  17. Culturability and concentration of indoor and outdoor airborne fungi in six single-family homes

    PubMed Central

    Lee, Taekhee; Grinshpun, Sergey A.; Martuzevicius, Dainius; Adhikari, Atin; Crawford, Carlos M.; Reponen, Tiina

    2008-01-01

    In this study, the culturability of indoor and outdoor airborne fungi was determined through long-term sampling (24-h) using a Button Personal Inhalable Aerosol Sampler. The air samples were collected during three seasons in six Cincinnati area homes that were free from moisture damage or visible mold. Cultivation and total microscopic enumeration methods were employed for the sample analysis. The geometric means of indoor and outdoor culturable fungal concentrations were 88 and 102 colony-forming units (CFU) m-3, respectively, with a geometric mean of the I/O ratio equal to 0.66. Overall, 26 genera of culturable fungi were recovered from the indoor and outdoor samples. For total fungal spores, the indoor and outdoor geometric means were 211 and 605 spores m-3, respectively, with a geometric mean of I/O ratio equal to 0.32. The identification revealed 37 fungal genera from indoor and outdoor samples based on the total spore analysis. Indoor and outdoor concentrations of culturable and total fungal spores showed significant correlations (r = 0.655, p<0.0001 and r = 0.633, p<0.0001, respectively). The indoor and outdoor median viabilities of fungi were 55% and 25%, respectively, which indicates that indoor environment provides more favorable survival conditions for the aerosolized fungi. Among the seasons, the highest indoor and outdoor culturability of fungi was observed in the fall. Cladosporium had a highest median value of culturability (38% and 33% for indoor and outdoor, respectively) followed by Aspergillus/Penicillium (9% and 2%) among predominant genera of fungi. Increased culturability of fungi inside the homes may have important implications because of the potential increase in the release of allergens from viable spores and pathogenicity of viable fungi on immunocompromised individuals. PMID:18458748

  18. Culturability and concentration of indoor and outdoor airborne fungi in six single-family homes

    NASA Astrophysics Data System (ADS)

    Lee, Taekhee; Grinshpun, Sergey A.; Martuzevicius, Dainius; Adhikari, Atin; Crawford, Carlos M.; Reponen, Tiina

    In this study, the culturability of indoor and outdoor airborne fungi was determined through long-term sampling (24-h) using a Button Personal Inhalable Aerosol Sampler. The air samples were collected during three seasons in six Cincinnati area homes that were free from moisture damage or visible mold. Cultivation and total microscopic enumeration methods were employed for the sample analysis. The geometric means of indoor and outdoor culturable fungal concentrations were 88 and 102 colony-forming units (CFU) m -3, respectively, with a geometric mean of the I/ O ratio equal to 0.66. Overall, 26 genera of culturable fungi were recovered from the indoor and outdoor samples. For total fungal spores, the indoor and outdoor geometric means were 211 and 605 spores m -3, respectively, with a geometric mean of I/ O ratio equal to 0.32. The identification revealed 37 fungal genera from indoor and outdoor samples based on the total spore analysis. Indoor and outdoor concentrations of culturable and total fungal spores showed significant correlations ( r=0.655, p<0.0001 and r=0.633, p<0.0001, respectively). The indoor and outdoor median viabilities of fungi were 55% and 25%, respectively, which indicates that indoor environment provides more favorable survival conditions for the aerosolized fungi. Among the seasons, the highest indoor and outdoor culturability of fungi was observed in the fall. Cladosporium had a highest median value of culturability (38% and 33% for indoor and outdoor, respectively) followed by Aspergillus/Penicillium (9% and 2%) among predominant genera of fungi. Increased culturability of fungi inside the homes may have important implications because of the potential increase in the release of allergens from viable spores and pathogenicity of viable fungi on immunocompromised individuals.

  19. Concentrations, sources and geochemistry of airborne particulate matter at a major European airport.

    PubMed

    Amato, Fulvio; Moreno, Teresa; Pandolfi, Marco; Querol, Xavier; Alastuey, Andrés; Delgado, Ana; Pedrero, Manuel; Cots, Nuria

    2010-04-01

    Monitoring of aerosol particle concentrations (PM(10), PM(2.5), PM(1)) and chemical analysis (PM(10)) was undertaken at a major European airport (El Prat, Barcelona) for a whole month during autumn 2007. Concentrations of airborne PM at the airport were close to those at road traffic hotspots in the nearby Barcelona city, with means measuring 48 microg PM(10)/m(3), 21 microg PM(2.5)/m(3) and 17 microg PM(1)/m(3). Meteorological controls on PM at El Prat are identified as cleansing daytime sea breezes with abundant coarse salt particles, alternating with nocturnal land-sourced winds which channel air polluted by industry and traffic (PM(1)/PM(10) ratios > 0.5) SE down the Llobregat Valley. Chemical analyses of the PM(10) samples show that crustal PM is dominant (38% of PM(10)), followed by total carbon (OC + EC, 25%), secondary inorganic aerosols (SIA, 20%), and sea salt (6%). Local construction work for a new airport terminal was an important contributor to PM(10) crustal levels. Source apportionment modelling PCA-MLRA identifies five factors: industrial/traffic, crustal, sea salt, SIA, and K(+) likely derived from agricultural biomass burning. Whereas most of the atmospheric contamination concerning ambient air PM(10) levels at El Prat is not attributable directly to aircraft movement, levels of carbon are unusually high (especially organic carbon), as are metals possibly sourced from tyre detritus/smoke in runway dust (Ba, Zn, Mo) and from brake dust in ambient PM(10) (Cu, Sb), especially when the airport is at its most busy. We identify microflakes of aluminous alloys in ambient PM(10) filters derived from corroded fuselage and wings as an unequivocal and highly distinctive tracer for aircraft movement. PMID:20383366

  20. Ambient monitoring of airborne asbestos in non-occupational environments in Tehran, Iran

    NASA Astrophysics Data System (ADS)

    Kakooei, Hossein; Meshkani, Mohsen; Azam, Kamal

    2013-12-01

    Airborne asbestos fiber concentrations were monitored in the urban areas of Tehran, Iran during the period of 23 August to 21 September 2012. The airborne fiber concentrations of 110 air samples collected from 15 different sites in five regions of Tehran. The monitoring sites were located 2.5 m above ground nearby the main street and heavy traffic jam. The ambient air samples were analyzed using scanning electron microscopy (SEM), with energy-dispersive X-ray analysis and phase-contrast optical microscopy (PCM). The geometric means of the airborne asbestos fiber concentrations in the outdoor living areas was 1.6 × 10-2 SEM f ml-1 (1.18 × 10-3 PCM f ml-1). This criteria is considerably higher than those reported for the levels of asbestos in outdoor living areas in the Europe and the non-occupational environment of the Korea. No clear correlation was found between asbestos fiber concentration and the relative humidity and temperature. The SEM and PLM analysis revealed that all samples examined contained only chrysotile asbestos. It can be concluded that several factor such as heavy traffic, cement sheet and pipe consumption of asbestos, and geographical conditions play an important role for the high airborne asbestos levels in the non-occupational environments.

  1. DIFFERENTIAL LUNG GENE EXPRESSION IN IMMUNOLOGICALLY-CHALLENGED RATS EXPOSED TO CONCENTRATED AIRBORNE PARTICULATES

    EPA Science Inventory

    Children residing in urbanized areas suffer disproportionately higher asthma-related morbidity and mortality. One explanation is that inner city children are exposured to higher levels of environmental asthma triggers such as airborne particulate matter. To elucidate gene-environ...

  2. Measured and modelled concentrations and vertical profiles of airborne particulate matter within the boundary layer of a street canyon.

    PubMed

    Colls, J J; Micallef, A

    1999-09-01

    Concentrations and vertical profiles of various fractions of airborne particulate matter (suspended particulate matter (SPM), PM10 and PM2.5) have been measured over the first three metres from ground in a street canyon. Measurements were carried out using automated near real-time apparatus called the Kinetic Sequential Sampling (KSS) system. KSS system is essentially an electronically-controlled lift carrying a real-time particle monitor for sampling air sequentially, at different heights within the breathing zone, which includes all heights within the surface layer of a street canyon at which people may breathe. Data is automatically logged at the different receptor levels, for the determination of the average vertical concentration profile of airborne particulate matter. For measuring the airborne particle concentration, a Grimm Dust Monitor 1.104/5 was used. The recorded data also allows for time series analysis of airborne particulate matter concentration at different heights. Time series data and hourly-average vertical concentration profiles in the boundary layer of the confines of a street are thought to be mainly determined by traffic emissions and traffic associated processes. Hence the measured data were compared with results of a street canyon emission-dispersion model in time and space. This Street Level Air Quality (SLAQ) model employs the plume-box technique and includes modules for simulating vehicle-generated effects such as thermally- and mechanically-generated turbulence and resuspension of road dust. Environmental processes, such as turbulence resulting from surface sensible heat and the formation of sulphate aerosol from sulphur dioxide exhaust emissions, are taken into account. The paper presents an outline description of the measuring technique and model used, and a comparison of the measured and modelled data. PMID:10535122

  3. Airborne in-situ spectral characterization and concentration estimates of fluorescent organics as a function of depth

    NASA Technical Reports Server (NTRS)

    Tittle, R. A.

    1988-01-01

    The primary purpose of many in-situ airborne light scattering experiments in natural waters is to spectrally characterize the subsurface fluorescent organics and estimate their relative concentrations. This is often done by shining a laser beam into the water and monitoring its subsurface return signal. To do this with the proper interpretation, depth must be taken into account. If one disregards depth dependence when taking such estimates, both their spectral characteristics and their concentrations estimates can be rather ambiguous. A simple airborne lidar configuration is used to detect the subsurface return signal from a particular depth and wavelength. Underwater scatterometer were employed to show that in-situ subsurface organics are very sensitive to depth, but they also require the use of slow moving boats to cover large sample areas. Also, their very entry into the water disturbs the sample it is measuring. The method described is superior and simplest to any employed thus far.

  4. FATE OF INGESTED CHRYSOTILE ASBESTOS FIBER IN THE NEWBORN BABOON

    EPA Science Inventory

    The objective of this research was to determine if orally administered chrysotile asbestos fibers could penetrate through the gastrointestinal tract of the neonate baboon and be recovered in selected tissues. A neonate baboon was given a cumulative dose of 3 to the 13th power chr...

  5. Temporal Variability of the Bioaerosol Background at a Subway Station: Concentration Level, Size Distribution, and Diversity of Airborne Bacteria

    PubMed Central

    Dybwad, Marius; Skogan, Gunnar

    2014-01-01

    Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 103 CFU m−3 and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents. PMID:24162566

  6. An Australian study to evaluate worker exposure to chrysotile in the automotive service industry.

    PubMed

    Yeung, P; Patience, K; Apthorpe, L; Willcocks, D

    1999-07-01

    A study was conducted in Sydney, Australia, in 1996 to investigate the current exposure levels, control technologies, and work practices in five service garages (four car and one bus), three brake bonding workshops, and one gasket processing workshop. This study formed part of the assessment of chrysotile as a priority existing chemical under the Australian National Industrial Chemicals Notification and Assessment Scheme. A total of 68 (11 personal and 57 area) air samples were collected, in accordance with the Australian standard membrane filter method. Fiber concentrations were determined by the traditional phase contrast microscopy (PCM) method and 16 selected samples were analyzed by the more powerful transmission electron microscopy (TEM). Chrysotile exposure of car mechanics measured by PCM was typically below the reportable detection limit of 0.05 f/mL, irrespective of whether disc brake, drum brake, or clutch was being serviced. These low levels can be attributed to the wet cleaning or aerosol spray methods used in recent years to replace the traditional compressed air jet cleaning. In the three brake shoe relining workshops, task-specific exposure reached up to 0.16 f/mL in the processes of cutting and radius grinding. TEM results were generally higher, due to its higher resolution power. The median diameter on samples taken from the service garages (passenger cars), as determined by TEM, was 0.5-1.0 micron; and was between 0.2-0.5 micron for the brake bonding and gasket processing workshops, while that for the bus service depot was 0.1-0.2 micron. Most of the respirable fibers (84%, mainly forsterite) from the bus service depot were below 0.2 micron in diameter which is the resolution limit of PCM. In the brake bonding and gasket cutting workshops, 34 percent and 44 percent of the chrysotile fibers were below 0.2 micron in diameter. PMID:10461401

  7. Lung proliferative and clearance responses to inhaled para-aramid RFP in exposed hamsters and rats: comparisons with chrysotile asbestos fibers.

    PubMed Central

    Warheit, D B; Snajdr, S I; Hartsky, M A; Frame, S R

    1997-01-01

    This study compared pulmonary effects of para-aramid respirable-sized, fiber-shaped particles (RFP) (p-aramid fibrils) and chrysotile asbestos fiber exposures in rats. Additional p-aramid inhalation studies were conducted in hamsters to compare species responses. The hamster results are preliminary. The parameters studied were clearance/biopersistence of inhaled p-aramid RFP or size-separated asbestos fibers as well as pulmonary cell proliferation and inflammation indices after 2-week inhalation exposures. Rats were exposed nose only to chrysotile asbestos fibers at concentrations of 459 and 782 fibers/ml or to p-aramid RFP at 419 or 772 fibrils/ml. Hamsters were exposed whole body to p-aramid RFP at concentrations of 358 and 659 fibrils/ml. Subsequently, animals were assessed immediately (time 0) as well as 5 days (10 days for hamsters), 1, 3, 6, and 12 months postexposure. Lung burdens for the p-aramid-exposed rats were 4.8 x 10(7) and 7.6 x 10(7) fibrils/lung, with similar numbers of chrysotile fibers > 5 microns recovered from the lungs of asbestos-exposed rats. In comparison, 1.4 x 10(6) fibrils/lung were recovered in the high-dose hamster group. Biopersistence studies in p-aramid-exposed rats and hamsters demonstrated an initial increase (relative to time 0) in retained p-aramid fibrils during the first month postexposure, which indicated breakage or shortening of inhaled fibrils. This result was associated with a progressive reduction, and increased residence time in the lung, in the mean lengths of the fibrils, which signified biodegradability of inhaled p-aramid fibrils in both species. In contrast, clearance of short chrysotile asbestos fibers was rapid, but clearance of the long chrysotile fibers was slow or insignificant, as evidenced by a progressive increase over time in the mean lengths of fibers recovered from the lungs of exposed rats. Two-week, high-dose exposures to p-aramid in both rats and hamsters produced transient increases in pulmonary

  8. Lung proliferative and clearance responses to inhaled para-aramid RFP in exposed hamsters and rats: comparisons with chrysotile asbestos fibers.

    PubMed

    Warheit, D B; Snajdr, S I; Hartsky, M A; Frame, S R

    1997-09-01

    This study compared pulmonary effects of para-aramid respirable-sized, fiber-shaped particles (RFP) (p-aramid fibrils) and chrysotile asbestos fiber exposures in rats. Additional p-aramid inhalation studies were conducted in hamsters to compare species responses. The hamster results are preliminary. The parameters studied were clearance/biopersistence of inhaled p-aramid RFP or size-separated asbestos fibers as well as pulmonary cell proliferation and inflammation indices after 2-week inhalation exposures. Rats were exposed nose only to chrysotile asbestos fibers at concentrations of 459 and 782 fibers/ml or to p-aramid RFP at 419 or 772 fibrils/ml. Hamsters were exposed whole body to p-aramid RFP at concentrations of 358 and 659 fibrils/ml. Subsequently, animals were assessed immediately (time 0) as well as 5 days (10 days for hamsters), 1, 3, 6, and 12 months postexposure. Lung burdens for the p-aramid-exposed rats were 4.8 x 10(7) and 7.6 x 10(7) fibrils/lung, with similar numbers of chrysotile fibers > 5 microns recovered from the lungs of asbestos-exposed rats. In comparison, 1.4 x 10(6) fibrils/lung were recovered in the high-dose hamster group. Biopersistence studies in p-aramid-exposed rats and hamsters demonstrated an initial increase (relative to time 0) in retained p-aramid fibrils during the first month postexposure, which indicated breakage or shortening of inhaled fibrils. This result was associated with a progressive reduction, and increased residence time in the lung, in the mean lengths of the fibrils, which signified biodegradability of inhaled p-aramid fibrils in both species. In contrast, clearance of short chrysotile asbestos fibers was rapid, but clearance of the long chrysotile fibers was slow or insignificant, as evidenced by a progressive increase over time in the mean lengths of fibers recovered from the lungs of exposed rats. Two-week, high-dose exposures to p-aramid in both rats and hamsters produced transient increases in pulmonary

  9. Crop harvest in Denmark and Central Europe contributes to the local load of airborne Alternaria spore concentrations in Copenhagen

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Sommer, J.; Frederiksen, L.; Gosewinkel Karlson, U.

    2012-11-01

    This study examines the hypothesis that Danish agricultural areas are the main source of airborne Alternaria spores in Copenhagen, Denmark. We suggest that the contribution to the overall load is mainly local or regional, but with intermittent long distance transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes (daily average spore concentration above 100 m-3) with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models.

  10. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    PubMed

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. PMID:26773821

  11. EVALUATION OF AIRBORNE ASBESTOS CONCENTRATIONS BEFORE AND DURING AND O&M ACTIVITY: A CASE STUDY

    EPA Science Inventory

    The current lack of information regarding the impact of O&M activities on the potential for asbestos exposure to building staff and occupants prompted this study. This report presents a statistical evaluation of airborne asbestos data collected before and during an O&M activity i...

  12. ESTIMATING DOWNWIND CONCENTRATIONS OF VIABLE AIRBORNE MICROORGANISMS IN DYNAMIC ATMOSPHERIC CONDITIONS (JOURNAL VERSION)

    EPA Science Inventory

    A Gaussian plume model has been modified to include an airborne microbial survival term that is a best-fit function of laboratory experimental data of weather variables. The model has been included in an algorithm using microbial source strength and local hourly mean weather data...

  13. 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

  14. A coupled model of the airborne and surface concentration of radionuclides considering the resuspension-deposition process

    NASA Astrophysics Data System (ADS)

    Ichige, Hiroyuki; Hatano, Yuko; Onda, Yuichi

    2014-05-01

    We propose a new model of estimating the long-term behavior of both the airborne and the surface concentrations of radionuclides in the vicinity of 30 km of Fukushima plant. Our model consists of the following simultaneous equations: δC- = viδC-+ ΛupS - ΛdownC - ΛdecC (1) δt δxi δS- = - Λ S + Λ C - Λ S, (2) δt up down env where C is the airborne concentration of a specific nuclide, S the surface concentration, the suffix i is 1 or 2 (2 dimensional), v the effective wind velocity which migrates the radionuclides in the air, Λup the rate constant of resuspension process, Λdown of deposition process, Λdec the decay constant, and Λenv is the rate constant of the surface concentration decrease due to environmental factors such as runoff, washoff, infiltrations, and the vegetation effects. These equations are based on our former study (Hatano and Hatano, 1997; Hatano et al., 1998) which successfully reproduce the long-term decrease of airborne concentration of the Chernobyl data such as Cs-137, Cs-134, Ce-144, and Ru-106 over nearly a decade. The first equation of the present study is essentially the same as our previous studies, besides that we added a new term for deposition. The second equation is newly added in the present study which describes the behavior of the surface concentration. In Fukushima case, we found that the radiation risk is much higher than the airborne concentration. That is why we add the second equation. Since the new model requires parameter values of Λs we need to estimate these values from actual data. In order to do so, we apply the method of inverse problem and thereby estimate the values. We also do the spectral analysis of the dose rate (mainly from Cs-137, -134) and study if it is possible to estimate the resuspended amount from the ground surface.

  15. Airborne DOAS measurements in Arctic: vertical distributions of aerosol extinction coefficient and NO2 concentration

    NASA Astrophysics Data System (ADS)

    Merlaud, A.; van Roozendael, M.; Theys, N.; Fayt, C.; Hermans, C.; Quennehen, B.; Schwarzenboeck, A.; Ancellet, G.; Pommier, M.; Pelon, J.; Burkhart, J.; Stohl, A.; de Mazière, M.

    2011-09-01

    We report on airborne Differential Optical Absorption Spectroscopy (DOAS) measurements of aerosol extinction and NO2 tropospheric profiles performed off the North coast of Norway in April 2008. The DOAS instrument was installed on the Safire ATR-42 aircraft during the POLARCAT-France spring campaign and recorded scattered light spectra in near-limb geometry using a scanning telescope. We use O4 slant column measurements to derive the aerosol extinction at 360 nm. Regularization is based on the maximum a posteriori solution, for which we compare a linear and a logarithmic approach. The latter inherently constrains the solution to positive values and yields aerosol extinction profiles more consistent with independently measured size distributions. We present results from two soundings performed on 8 April 2008 above 71° N, 22° E and on 9 April 2008 above 70° N, 17.8° E. The first profile shows aerosol extinction and NO2 in the marine boundary layer with respective values of 0.04 ± 0.005 km-1 and 1.9 ± 0.3 × 109 molec cm-3. A second extinction layer of 0.01 ± 0.003 km-1 is found at 4 km altitude where the NO2 concentration is 0.32 ± 0.2 × 109 molec cm-3. During the second sounding, clouds prevent retrieval of profile parts under 3 km altitude but a layer with enhanced extinction (0.025 ± 0.005 km-1) and NO2 (1.95 ± 0.2 × 109 molec cm-3) is clearly detected at 4 km altitude. From CO and ozone in-situ measurements complemented by back-trajectories, we interpret the measurements in the free troposphere as, for the first sounding, a mix between stratospheric and polluted air from Northern Europe and for the second sounding, polluted air from Central Europe containing NO2. Considering the boundary layer measurements of the first flight, modeled source regions indicate closer sources, especially the Kola Peninsula smelters, which can explain the NO2 enhancement not correlated with a CO increase at the same altitude.

  16. Effects of ceiling-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building.

    PubMed

    Kujundzic, Elmira; Zander, David A; Hernandez, Mark; Angenent, Largus T; Henderson, David E; Miller, Shelly L

    2005-02-01

    The purpose of this study was to assess the effectiveness of a new generation of high-volume, ceiling-mounted high-efficiency particulate air (HEPA)-ultraviolet (UV) air filters (HUVAFs) for their ability to remove or inactivate bacterial aerosol. In an environmentally controlled full-scale laboratory chamber (87 m3), and an indoor therapy pool building, the mitigation ability of air filters was assessed by comparing concentrations of total bacteria, culturable bacteria, and airborne endotoxin with and without the air filters operating under otherwise similar conditions. Controlled chamber tests with pure cultures of aerosolized Mycobacterium parafortuitum cells showed that the HUVAF unit tested provided an equivalent air-exchange rate of 11 hr(-1). Using this equivalent air-exchange rate as a design basis, three HUVAFs were installed in an indoor therapy pool building for bioaerosol mitigation, and their effectiveness was studied over a 2-year period. The HUVAFs reduced concentrations of culturable bacteria by 69 and 80% during monitoring periods executed in respective years. The HUVAFs reduced concentrations of total bacteria by 12 and 76% during the same monitoring period, respectively. Airborne endotoxin concentrations were not affected by the HUVAF operation. PMID:15796111

  17. Neoproterozoic Cana Brava chrysotile deposit (Goiás, Brazil): Geology and geochemistry of chrysotile vein formation

    NASA Astrophysics Data System (ADS)

    Biondi, João Carlos

    2014-01-01

    The Cana Brava chrysotile asbestos deposit of Goiás, Brazil, contains approximately 150 Mt of ore with an average of 3.5 wt.% of cross-fiber chrysotile and lies in the differentiated, mafic-ultramafic Neoproterozoic Cana Brava complex. This complex was formed at approximately 0.79 Ga and metamorphosed at 0.77 to 0.76 and 0.63 Ga. The 0.77 to 0.76 Ga metamorphic event was a high-grade one that transformed the mafic and ultramafic rocks into meta-peridotites and meta-pyroxenites. The low-grade 0.63 Ga metamorphism allowed the formation of black, red and brown serpentinite, graphitic, magnesite-rich talc serpentinite, and rodingite, which became folded and foliated. At the end of the 0.63 Ga metamorphism, black serpentinites were oxidized to form red serpentinites, the main type of serpentinite that outcrops today at the Cana Brava mineralized region. Post-metamorphic fluids reactivated the process of serpentinization, thereby generating massive green serpentinite from the red. Green formed on the most fractured zones, and double red and green reaction rims formed on the sides of the veins located outside the green serpentinite zones. This process did not cause significant variation in the volume of the rocks and resulted in a strongly reducing system thanks to the loss of Fe2O3 and iron and the subsequent crystallization of magnetite within veinlets and altered rocks. Low angle shear, developed under brittle conditions, caused hydraulic fracturing and the generation of oversaturated, oxidizing fluids that crystallized the cross-fiber chrysotile inside open fractures. Very densely fractured zones with fractures filled with cross-fiber chrysotile constitute the ore that is mined at present.

  18. Correlation between airborne Olea europaea pollen concentrations and levels of the major allergen Ole e 1 in Córdoba, Spain, 2012-2014

    NASA Astrophysics Data System (ADS)

    Plaza, M. P.; Alcázar, P.; Galán, C.

    2016-04-01

    Olea europaea L. pollen is the second-largest cause of pollinosis in the southern Iberian Peninsula. Airborne-pollen monitoring networks provide essential data on pollen dynamics over a given study area. Recent research, however, has shown that airborne pollen levels alone do not always provide a clear indicator of actual exposure to aeroallergens. This study sought to evaluate correlations between airborne concentrations of olive pollen and Ole e 1 allergen levels in Córdoba (southern Spain), in order to determine whether atmospheric pollen concentrations alone are sufficient to chart changes in hay fever symptoms. The influence of major weather-related variables on local airborne pollen and allergen levels was also examined. Monitoring was carried out from 2012 to 2014. Pollen sampling was performed using a Hirst-type sampler, following the protocol recommended by the Spanish Aerobiology Network. A multi-vial cyclone sampler was used to collect aeroallergens, and allergenic particles were quantified by ELISA assay. Significant positive correlations were found between daily airborne allergen levels and atmospheric pollen concentrations, although there were occasions when allergen was detected before and after the pollen season and in the absence of airborne pollen. The correlation between the two was irregular, and pollen potency displayed year-on-year variations and did not necessarily match pollen-season-intensity.

  19. Airborne Particulate Matter in Two Multi-Family Green Buildings: Concentrations and Effect of Ventilation and Occupant Behavior

    PubMed Central

    Patton, Allison P.; Calderon, Leonardo; Xiong, Youyou; Wang, Zuocheng; Senick, Jennifer; Sorensen Allacci, MaryAnn; Plotnik, Deborah; Wener, Richard; Andrews, Clinton J.; Krogmann, Uta; Mainelis, Gediminas

    2016-01-01

    There are limited data on air quality parameters, including airborne particulate matter (PM) in residential green buildings, which are increasing in prevalence. Exposure to PM is associated with cardiovascular and pulmonary diseases, and since Americans spend almost 90% of their time indoors, residential exposures may substantially contribute to overall airborne PM exposure. Our objectives were to: (1) measure various PM fractions longitudinally in apartments in multi-family green buildings with natural (Building E) and mechanical (Building L) ventilation; (2) compare indoor and outdoor PM mass concentrations and their ratios (I/O) in these buildings, taking into account the effects of occupant behavior; and (3) evaluate the effect of green building designs and operations on indoor PM. We evaluated effects of ventilation, occupant behaviors, and overall building design on PM mass concentrations and I/O. Median PMTOTAL was higher in Building E (56 µg/m3) than in Building L (37 µg/m3); I/O was higher in Building E (1.3–2.0) than in Building L (0.5–0.8) for all particle size fractions. Our data show that the building design and occupant behaviors that either produce or dilute indoor PM (e.g., ventilation systems, combustion sources, and window operation) are important factors affecting residents’ exposure to PM in residential green buildings. PMID:26805862

  20. Airborne Particulate Matter in Two Multi-Family Green Buildings: Concentrations and Effect of Ventilation and Occupant Behavior.

    PubMed

    Patton, Allison P; Calderon, Leonardo; Xiong, Youyou; Wang, Zuocheng; Senick, Jennifer; Sorensen Allacci, MaryAnn; Plotnik, Deborah; Wener, Richard; Andrews, Clinton J; Krogmann, Uta; Mainelis, Gediminas

    2016-01-01

    There are limited data on air quality parameters, including airborne particulate matter (PM) in residential green buildings, which are increasing in prevalence. Exposure to PM is associated with cardiovascular and pulmonary diseases, and since Americans spend almost 90% of their time indoors, residential exposures may substantially contribute to overall airborne PM exposure. Our objectives were to: (1) measure various PM fractions longitudinally in apartments in multi-family green buildings with natural (Building E) and mechanical (Building L) ventilation; (2) compare indoor and outdoor PM mass concentrations and their ratios (I/O) in these buildings, taking into account the effects of occupant behavior; and (3) evaluate the effect of green building designs and operations on indoor PM. We evaluated effects of ventilation, occupant behaviors, and overall building design on PM mass concentrations and I/O. Median PMTOTAL was higher in Building E (56 µg/m³) than in Building L (37 µg/m³); I/O was higher in Building E (1.3-2.0) than in Building L (0.5-0.8) for all particle size fractions. Our data show that the building design and occupant behaviors that either produce or dilute indoor PM (e.g., ventilation systems, combustion sources, and window operation) are important factors affecting residents' exposure to PM in residential green buildings. PMID:26805862

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

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  2. 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.

  3. Influence of atmospheric ozone, PM 10 and meteorological factors on the concentration of airborne pollen and fungal spores

    NASA Astrophysics Data System (ADS)

    Sousa, S. I. V.; Martins, F. G.; Pereira, M. C.; Alvim-Ferraz, M. C. M.; Ribeiro, H.; Oliveira, M.; Abreu, I.

    The increase of allergenic symptoms has been associated with air contaminants such as ozone, particulate matter, pollen and fungal spores. Considering the potential relevance of crossed effects of non-biological pollutants and airborne pollens and fungal spores on allergy worsening, the aim of this work was to evaluate the influence of non-biological pollutants and meteorological parameters on the concentrations of pollen and fungal spores using linear correlations and multiple linear regressions. For that, the seasonal variation of ozone, particulate matter with an equivalent aerodynamic diameter smaller than 10 μm, pollen and fungal spores were assessed and statistical correlations were analysed between those parameters. The data were collected through 2003-2005 in Porto, Portugal. The linear correlations showed that ozone and particulate matter had no significant influence on the concentration of pollen and fungal spores. On the contrary, when using multiple linear regressions those parameters showed to have some influence on the biological pollutants, although results were different depending on the year analysed. Among the meteorological parameters analysed, temperature was the one that most influenced the pollen and fungal spores airborne concentrations, both when using linear and multiple linear correlations. Relative humidity also showed to have some influence on the fungal spore dispersion when multiple linear regressions were used. Nevertheless, the conclusions for each pollen and fungal spore were different depending on the analysed period, which means that the correlations identified as statistically significant may not be, even so, consistent enough. Furthermore, the comparison of the results here presented with those obtained by other authors for only one period should be made carefully.

  4. Airborne black carbon concentrations over an urban region in western India-temporal variability, effects of meteorology, and source regions.

    PubMed

    Bapna, Mukund; Sunder Raman, Ramya; Ramachandran, S; Rajesh, T A

    2013-03-01

    This study characterizes over 5 years of high time resolution (5 min), airborne black carbon (BC) concentrations (July 2003 to December 2008) measured over Ahmedabad, an urban region in western India. The data were used to obtain different time averages of BC concentrations, and these averages were then used to assess the diurnal, seasonal, and annual variability of BC over the study region. Assessment of diurnal variations revealed a strong association between BC concentrations and vehicular traffic. Peaks in BC concentration were co-incident with the morning (0730 to 0830, LST) and late evening (1930 to 2030, LST) rush hour traffic. Additionally, diurnal variability in BC concentrations during major festivals (Diwali and Dushera during the months of October/November) revealed an increase in BC concentrations due to fireworks displays. Maximum half hourly BC concentrations during the festival days were as high as 79.8 μg m(-3). However, the high concentrations rapidly decayed suggesting that local meteorology during the festive season was favorable for aerosol dispersion. A multiple linear regression (MLR) model with BC as the dependent variable and meteorological parameters as independent variables was fitted. The variability in temperature, humidity, wind speed, and wind direction accounted for about 49% of the variability in measured BC concentrations. Conditional probability function (CPF) analysis was used to identify the geographical location of local source regions contributing to the effective BC measured (at 880 nm) at the receptor site. The east north-east (ENE) direction to the receptor was identified as a major source region. National highway (NH8) and two coal-fired thermal power stations (at Gandhinagar and Sabarmati) were located in the identified direction, suggesting that local traffic and power plant emissions were likely contributors to the measured BC. PMID:22777610

  5. Mining in subarctic Canada: airborne PM2.5 metal concentrations in two remote First Nations communities.

    PubMed

    Liberda, Eric N; Tsuji, Leonard J S; Peltier, Richard E

    2015-11-01

    Airborne particulate matter arising from upwind mining activities is a concern for First Nations communities in the western James Bay region of Ontario, Canada. Aerosol chemical components were collected in 2011 from two communities in northern Ontario. The chemical and mass concentration data of particulate matter collected during this study shows a significant difference in PM2.5 in Attawapiskat compared to Fort Albany. Elemental profiles indicate enhanced levels of some tracers thought to arise from mining activities, such as, K, Ni, and crustal materials. Both communities are remote and isolated from urban and industrial pollution sources, however, Attawapiskat First Nation has significantly enhanced levels of particulate matter, and it is likely that some of this arises from upwind mining activities. PMID:26255141

  6. A biopersistence study following exposure to chrysotile asbestos alone or in combination with fine particles.

    PubMed

    Bernstein, D M; Donaldson, K; Decker, U; Gaering, S; Kunzendorf, P; Chevalier, J; Holm, S E

    2008-09-01

    In designing a study to evaluate the inhalation biopersistence of a chrysotile asbestos that was used as a component of a joint-compound, a feasibility study was initiated to evaluate the short-term biopersistence of the chrysotile alone and of the chrysotile in combination with the sanded reformulated joint-compound. Two groups of Wistar rats were exposed to either 7RF3 chrysotile (Group 2) or to 7RF3 chrysotile combined with aerosolized sanded joint-compound (Group 3). In addition, a control group was exposed to filtered-air. The chrysotile used in the Ready Mix joint compound is rapidly removed from the lung. The chrysotile alone exposure group had a clearance half-time of fibers L > 20 microm of 2.2 days; in the chrysotile plus sanded exposure group the clearance half-time of fibers L > 20 microm was 2.8 days. However, across all size ranges there was approximately an order of magnitude decrease in the mean number of fibers remaining in the lungs of Group 3 as compared to Group 2 despite similiar aerosol exposures. Histopathological examination showed that the chrysotile exposed lungs had the same appearance as the filtered-air controls. This study uniquely illustrates that additional concurrent exposure to an aerosol of the sanded joint-compound, with large numbers of fine-particles depositing in the lungs, accelerates the recruitment of macrophages, resulting in a tenfold decrease in the number of fibers remaining in the lung. The increased number of macrophages in the chrysotile/sanded joint exposure group was confirmed histologically, with this being the only exposure-related histological finding reported. PMID:18788018

  7. A Biopersistence Study following Exposure to Chrysotile Asbestos Alone or in Combination with Fine Particles

    PubMed Central

    Bernstein, D. M.; Donaldson, K.; Decker, U.; Gaering, S.; Kunzendorf, P.; Chevalier, J.; Holm, S. E.

    2008-01-01

    In designing a study to evaluate the inhalation biopersistence of a chrysotile asbestos that was used as a component of a joint-compound, a feasibility study was initiated to evaluate the short-term biopersistence of the chrysotile alone and of the chrysotile in combination witht the sanded reformulated joint-compound. Two groups of Wistar rats were exposed to either 7RF3 chrysotile (Group 2) or to 7RF3 chrysotile combined with aerosolized sanded joint-compound (Group 3). In addition, a control group was exposed to flltered-air. The chrysotile used in the Ready Mix joint compound is rapidly removed from the lung. The chrysotile alone exposure group had a clearance half-time of fibers L > 20 μm of 2.2 days; in the chrysotile plus sanded exposure group the clearance half-time of fibers L > 20 μm was 2.8 days. However, across all size ranges there was approximately an order of magnitude decrease in the mean number of fibers remaining in the lungs of Group 3 as compared to Group 2 despite similiar aerosol exposures. Histopathological examination showed that the chrysotile exposed lungs had the same appearance as the flltered-air controls. This study uniquely illustrates that additional concurrent exposure to an aerosol of the sanded joint-compound, with large numbers of fine-particles depositing in the lungs, accelerates the recruitment of macrophages, resulting in a tenfold decrease in the number of fibers remaining in the lung. The increased number of macrophages in the chrysotile/sanded joint exposure group was confirmed histologically, with this being the only exposure-related histological finding reported. PMID:18788018

  8. Thermal modification of chrysotile asbestos: evidence for decreased cytotoxicity.

    PubMed Central

    Valentine, R; Chang, M J; Hart, R W; Finch, G L; Fisher, G L

    1983-01-01

    Many asbestiform minerals exhibit temperature-dependent thermoluminescence. Since thermoluminescence involves electronic transitions within crystalline materials, the effect of temperature on asbestos cytotoxicity was evaluated. Heat pretreatment of Canadian chrysotile asbestos reduces its cytotoxicity towards cultured human fibroblasts and bovine alveolar macrophages. When monitored 44 hr after the addition of either 200 degrees C or 400 degrees C heat-pretreated asbestos, alveolar macrophage viability was approximately 40% higher than comparable amounts of unheated asbestos. Similarly, asbestos toxicity, expressed as fibroblast growth inhibition, was inversely related to the asbestos pretreatment temperature in the following manner, 70 degrees C greater than 200 degrees C greater than 400 degrees C = unexposed fibroblast controls. Pretreatment of chrysotile asbestos to 400 degrees C reduced its adsorptive capacity for bovine serum albumin by 25%. Furthermore, asbestos heated to 200 degrees C followed by irradiation with 4 MeV X-rays (4500 rads) resulted in reactivation of asbestos cytotoxicity. Scanning electron microscopy indicated that the ratios of free to fiber-associated alveolar macrophages and the fiber fragment size distributions were unaffected by either heat pretreatment or X-ray irradiation. These observations strongly suggest that the surface charge characteristics and electronic state of asbestos fibers may be responsible for its biological activity. Images FIGURE 4. FIGURE 5. (A) FIGURE 5. (B) FIGURE 6. (A) FIGURE 6. (B) FIGURE 6. (C) FIGURE 6. (D) FIGURE 7. PMID:6315379

  9. Historical ambient airborne asbestos concentrations in the United States - an analysis of published and unpublished literature (1960s-2000s).

    PubMed

    Abelmann, Anders; Glynn, Meghan E; Pierce, Jennifer S; Scott, Paul K; Serrano, Samantha; Paustenbach, Dennis J

    2015-01-01

    Outdoor concentrations of airborne asbestos have been measured throughout the US over time. However, a thorough review and analysis of these data has not been conducted. The purpose of this study is to characterize asbestos concentrations in ambient air by environment type (urban, rural) and by decade, using measurements collected in the absence of known asbestos emission sources. A total of 17 published and unpublished studies and datasets were identified that reported the results of 2058 samples collected from the 1960s through the 2000s across the US. Most studies did not report asbestos fiber type, and data based on different analytical methods (e.g. Phase Contrast Microscopy, Transmission Electron Microscopy, etc.) were combined in the dataset; however, only fibers ≥5 μm in length were considered. For a small subset of the measurements (n = 186, 9.0%), a conversion factor was used to convert mass-based data (e.g. ng/m(3)) to count-based values (i.e. f/cc ≥5 μm). The estimated overall mean and median ambient asbestos concentrations for the 1960s through 2000s were 0.00093 f/cc and 0.00022 f/cc, respectively. Concentrations generally increased from the 1960s through the early 1980s, after which they declined considerably. While asbestos use decreased throughout the 1970s, these results indicate that ambient concentrations peaked during the early 1980s, which suggests the possible contribution of abatement or demolition activities. Lastly, ambient asbestos concentrations were higher in urban than rural settings, which is consistent with the greater use of asbestos-containing materials in more densely populated areas. PMID:26671195

  10. Airborne DOAS measurements in Arctic: vertical distributions of aerosol extinction coefficient and NO2 concentration

    NASA Astrophysics Data System (ADS)

    Merlaud, A.; van Roozendael, M.; Theys, N.; Fayt, C.; Hermans, C.; Quennehen, B.; Schwarzenboeck, A.; Ancellet, G.; Pommier, M.; Pelon, J.; Burkhart, J.; Stohl, A.; de Mazière, M.

    2011-05-01

    We report airborne differential optical absorption spectroscopy (DOAS) measurements of aerosol extinction and NO2 tropospheric profiles performed off the North coast of Norway in April 2008. The DOAS instrument was installed on the Safire ATR-42 aircraft during the POLARCAT-France spring campaign and recorded scattered light spectra in near-limb geometry using a scanning telescope. We use O4 slant column measurements to derive the aerosol extinction at 360 nm. Regularization is based on the maximum a posteriori solution, for which we compare a linear and a logarithmic approach. The latter inherently constrains the solution to positive values and yields aerosol extinction profiles more consistent with independently measured size distributions. Two soundings are presented, performed on 8 April 2008 above 71° N, 22° E and on 9 April 2008 above 70° N, 17.8° E. The first profile shows aerosol extinction and NO2 in the marine boundary layer with respective values of 0.04±0.005 km-1 and 1.9±0.3 × 109 molec cm-3. A second extinction layer of 0.01±0.003 km-1 is found at 4 km altitude. During the second sounding, clouds prevented us to retrieve profile parts under 3 km altitude but a layer with enhanced extinction (0.025±0.005 km-1) and NO2 (1.95±0.2 × 109 molec cm-3) is clearly detected at 4 km altitude. From CO and ozone in-situ measurements complemented by back-trajectories, we interpret the measurements in the free troposphere as, for the first sounding, a mix between stratospheric and polluted air from Northern Europe and for the second sounding, polluted air from Central Europe containing NO2. Considering the boundary layer measurements of the first flight, modeled source regions indicate closer sources, especially the Kola Peninsula smelters, which can explain the NO2 enhancement not correlated with a CO increase at the same altitude.

  11. Vinyl flooring in the home is associated with children's airborne butylbenzyl phthalate and urinary metabolite concentrations.

    PubMed

    Just, Allan C; Miller, Rachel L; Perzanowski, Matthew S; Rundle, Andrew G; Chen, Qixuan; Jung, Kyung Hwa; Hoepner, Lori; Camann, David E; Calafat, Antonia M; Perera, Frederica P; Whyatt, Robin M

    2015-01-01

    Prior studies have shown that vinyl flooring as well as the vinyl-softening plasticizers butylbenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) are associated with asthma and airway inflammation. Although DEHP exposure is primarily dietary, whether home vinyl flooring contributes to indoor air and urinary metabolite concentrations for these two phthalates is unclear. Exposures to BBzP and DEHP were examined in a prospective birth cohort of New York City children (n=239) using: (i) visual observation of potential phthalate containing flooring, (ii) a 2-week home indoor air sample, and (iii) concurrent urinary metabolites in a subset (n=193). The category "vinyl or linoleum" flooring was observed in 135 (56%) of monitored rooms; these rooms had statistically significantly higher indoor air geometric mean concentrations of BBzP (23.9 ng/m(3)) than rooms with wood or carpet flooring (10.6 ng/m(3)). Children from homes with "vinyl or linoleum" flooring also had significantly higher urinary BBzP metabolite concentrations than other children. Indoor air BBzP and urinary metabolite concentrations were correlated positively (Spearman's rho 0.40). By contrast, indoor air DEHP was not associated with flooring type nor with its urinary metabolite concentrations. Vinyl flooring in the home may be an important source of children's exposure to BBzP via indoor air. PMID:25690585

  12. Spatial variations in airborne microorganism and endotoxin concentrations at green waste composting facilities.

    PubMed

    Pankhurst, L J; Deacon, L J; Liu, J; Drew, G H; Hayes, E T; Jackson, S; Longhurst, P J; Longhurst, J W S; Pollard, S J T; Tyrrel, S F

    2011-09-01

    The emission and dispersal of bioaerosols from open-air commercial composting facilities continues to be contentious. A meta-dataset enumerating cultivable microorganism emission and downwind concentrations is not yet available. A dataset derived from repeated and replicated field studies over a period of two years at two commercial composting facilities is presented. The data characterises patterns in Aspergillus fumigatus, actinomycetes, Gram-negative bacteria and endotoxin emission and downwind concentrations. For all bioaerosols, compost agitation activities had a significant impact on concentrations; levels were variable up to 600 m downwind from site. Bioaerosols declined rapidly from source and exhibited a secondary peak 100-150 m from site boundary. All bioaerosols were found downwind from site in elevated concentrations. Compared to those found 100 m upwind, levels were significantly higher at 180 m downwind for A. fumigatus; at 300-400 m for actinomycetes and Gram negative bacteria, and at 100 m for endotoxins. Periodically, elevated concentrations could be found for all bioaerosols at distances further downwind. The evidence provided by this data set provides operators and regulators of facilities with reliable data to inform the location, risk assessment and bioaerosol sampling strategies of commercial composting facilities. PMID:21737345

  13. Vertical distribution of aerosol number concentration in the troposphere over Siberia derived from airborne in-situ measurements

    NASA Astrophysics Data System (ADS)

    Arshinov, Mikhail Yu.; Belan, Boris D.; Paris, Jean-Daniel; Machida, Toshinobu; Kozlov, Alexandr; Malyskin, Sergei; Simonenkov, Denis; Davydov, Denis; Fofonov, Alexandr

    2016-04-01

    Knowledge of the vertical distribution of aerosols particles is very important when estimating aerosol radiative effects. To date there are a lot of research programs aimed to study aerosol vertical distribution, but only a few ones exist in such insufficiently explored region as Siberia. Monthly research flights and several extensive airborne campaigns carried out in recent years in Siberian troposphere allowed the vertical distribution of aerosol number concentration to be summarized. In-situ aerosol measurements were performed in a wide range of particle sizes by means of improved version of the Novosibirsk-type diffusional particle sizer and GRIMM aerosol spectrometer Model 1.109. The data on aerosol vertical distribution enabled input parameters for the empirical equation of Jaenicke (1993) to be derived for Siberian troposphere up to 7 km. Vertical distributions of aerosol number concentration in different size ranges averaged for the main seasons of the year will be presented. This work was supported by Interdisciplinary integration projects of the Siberian Branch of the Russian Academy of Science No. 35, No. 70 and No. 131; the Branch of Geology, Geophysics and Mining Sciences of RAS (Program No. 5); and Russian Foundation for Basic Research (grant No. 14-05-00526). Jaenicke R. Tropospheric aerosols, in Aerosol-Cloud-Climate Interactions, edited by P.V. Hobs. -Academic Press, San Diego, CA, 1993.- P. 1-31.

  14. ELECTRON MICROSCOPE MEASUREMENT OF AIRBORNE ASBESTOS CONCENTRATIONS - A PROVISIONAL METHODOLOGY MANUAL

    EPA Science Inventory

    This manual describes a provisional optimum electron microscope (EM) procedure for measuring the concentration of asbestos in air samples. The main features of the method include depositing an air sample on a polycarbonate membrane filter, examining an EM grid specimen in a trans...

  15. ELECTRON MICROSCOPE MEASUREMENT OF AIRBORNE ASBESTOS CONCENTRATIONS. A PROVISIONAL METHODOLOGY MANUAL

    EPA Science Inventory

    This manual describes a provisional optimum electron microscope (EM) procedure for measuring the concentration of asbestos in air samples. The main features of the method include depositing an air sample on a polycarbonate membrane filter, examining an EM grid specimen in a trans...

  16. Impact of spatiotemporal fluctuations in airborne chemical concentration on toxic hazard assessment.

    PubMed

    Bogen, K T; Gouveia, F J

    2008-03-21

    Models widely used to assess atmospheric chemical-dispersion hazards for emergency response rely on acute exposure guideline level (AEGL) or similar concentration guidelines to map geographic areas potentially affected by corresponding levels of toxic severity. By ignoring substantial, random variability in concentration over time and space, such standard methods routinely underestimate the size of potentially affected areas. Underestimation due to temporal fluctuation - applicable to chemicals like hydrogen cyanide (HCN) for which peak concentrations best predict acute toxicity - becomes magnified by spatial fluctuation, defined as heterogeneity in average concentration at each location relative to standard-method predictions. The combined impact of spatiotemporal fluctuation on size of assessed threat areas was studied using a statistical-simulation assessment method calibrated to Joint Urban 2003 Oklahoma City field-tracer data. For a hypothetical 60-min urban release scenario involving HCN gas, the stochastic method predicted that lethal/severe effects could occur in an area 18 or 25 times larger than was predicted by standard methods targeted to a 60-min AEGL, assuming wind speeds > or =2.0 or < or =1.5m/s, respectively. The underestimation doubled when the standard method was targeted to a 10-min AEGL. Further research and field data are needed for improved stochastic methods to assess spatiotemporal fluctuation effects. PMID:17706864

  17. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

    PubMed Central

    Toro A., Richard; Córdova J., Alicia; Canales, Mauricio; Morales S., Raul G. E.; Mardones P., Pedro; Leiva G., Manuel A.

    2015-01-01

    Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. PMID:25946339

  18. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile.

    PubMed

    Toro A, Richard; Córdova J, Alicia; Canales, Mauricio; Morales S, Raul G E; Mardones P, Pedro; Leiva G, Manuel A

    2015-01-01

    Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009-2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies. PMID:25946339

  19. [Comparative carcinogenic properties of basalt fiber and chrysotile-asbestos].

    PubMed

    Nikitina, O V; Kogan, F M; Vanchugova, N N; Frash, V N

    1989-01-01

    In order to eliminate asbestos adverse effect on workers' health it was necessary to use mineral rayon, primarily basalt fibre, instead of asbestos. During a chronic experiment on animals the oncogenicity of 2 kinds of basalt fibre was studied compared to chrysotile asbestos. The dust dose of 25 mg was twice administered by intraperitonial route. All types of dust induced the onset of intraperitonial mesotheliomas but neoplasm rates were significantly lower in the groups exposed to basalt fibre. There was no credible data on the differences between the groups exposed to various types of basalt fibre. Since the latter produced some oncogenic effect, it was necessary to develop a complex of antidust measures, fully corresponding to the measures adopted for carcinogenic dusts. PMID:2545547

  20. 3D Trace gas concentration distributions from groundbased and airborne tomographic DOAS measurements

    NASA Astrophysics Data System (ADS)

    Pundt, I.; Hak, C.; Hartl, A.; Heue, K.-P.; Knab, V.; Kunz, C.; Laepple, T.; Lee, W.-D.; Mettendorf, K. U.; Sun, H.

    2003-04-01

    An overview on the AFO-2000 project "Tom-DOAS" is given. The project aims the assessment of concentration maps from DOAS measurements performed from ground or aircraft with more than ten light beams. 1) A first ground-based experiment was set up in April/May 2001 during the motorway campaign BABII (organised by Fiedler et al.): Two DOAS telescopes were directed onto eight retro reflector arrays mounted on two cranes, providing 16 light beams in total. From the data Luff and Lee profiles and the emission plumes of NO2 and ozone could be derived. 2) A new telescope type, the Multibeam telescope, was developed for the simultaneous measurement of multiple paths at ground. 3) An aircraft instrument was developed and about 20 flight hours of Tom-DOAS measurements were performed onboard a Partenavia aircraft in the Milano area (Italy) in the frame of the EU "FORMAT" project (July/August 2002) - in co-operation with the Institut für Umweltphysik of the University of Bremen 4) A new inversion software, "TOMOLAB", was developed, which converts the DOAS column data to concentration maps. It is used for the optimisation of tomographic setups using model data, e.g. for flight track choices, as well as for the inversion of real data sets from the measurements.

  1. Airborne fine particulate pollution in Jinan, China: Concentrations, chemical compositions and influence on visibility impairment

    NASA Astrophysics Data System (ADS)

    Yang, Lingxiao; Zhou, Xuehua; Wang, Zhe; Zhou, Yang; Cheng, Shuhui; Xu, Pengju; Gao, Xiaomei; Nie, Wei; Wang, Xinfeng; Wang, Wenxing

    2012-08-01

    Daily PM2.5 samples were collected simultaneously at an urban site (SD) and a rural site (MP) in Jinan, China from March 2006 to February 2007. The samples were analyzed for major inorganic and organic water-soluble ions, 24 elements and carbonaceous species to determine the spatial and temporal variations of PM2.5 mass concentrations and chemical compositions and evaluate their contributions to visibility impairment. The annual average concentrations of PM2.5 were 148.71 μg m-3 and 97.59 μg m-3 at SD and MP, respectively. The predominant component of PM2.5 was (NH4)2SO4 at SD and organic mass at MP, which accounted for 28.71% and 37.25% of the total mass, respectively. The higher SOR (sulfur oxidation ratio) and ratios of OC/EC at SD indicated that the formation of secondary inorganic ions and secondary organic aerosols (SOA) could be accelerated in the urban area. Large size (NH4)2SO4 and large size organic mass were the most important contributors to visibility impairment at SD and MP, accounting for 43.80% and 41.02% of the light extinction coefficient, respectively.

  2. Deriving the concentration of airborne ash with a CAS-DPOL instrument: assessing uncertainties introduced by the instrument design

    NASA Astrophysics Data System (ADS)

    Spanu, Antonio; Weinzierl, Bernadett; Freudenthaler, Volker; Sauer, Daniel; Gasteiger, Josef

    2016-04-01

    Explosive volcanic eruptions inject large amounts of gas and particles into the atmosphere resulting in strong impacts on anthropic systems and climate. Fine ash particles in suspension, even if at low concentrations, are a serious aviation safety hazard. A key point to predict the dispersion and deposition of volcanic ash is the knowledge of emitted mass and its particle size distribution. Usually the deposit is used to characterize the source but a large uncertainty is present for fine and very fine ash particles which are usually not well preserved. Conversely, satellite observations provide only column-integrated information and are strongly sensitive to cloud conditions above the ash plumes. Consequently, in situ measurements are fundamental to extend our knowledge on ash clouds, their properties, and interactions over the vertical extent of the atmosphere. Different in-situ instruments are available covering different particle size ranges using a variety of measurement techniques. Depending on the measurement technique, artefacts due to instrument setup and ambient conditions can strongly modify the measured number concentration and size distribution of the airborne particles. It is fundamental to correct for those effects to quantify the uncertainty associated with the measurement. Here we evaluate the potential of our optical light-scattering spectrometer CAS-DPOL to detect airborne mineral dust and volcanic ash (in the size range between 0.7μm and 50μm) and to provide a reliable estimation of the mass concentration, investigating the associate uncertainty. The CAS-DPOL instrument sizes particles by detecting the light scattered off the particle into a defined angle. The associated uncertainty depends on the optical instrument design and on unknown particles characteristics such as shape and material. Indirect measurements of mass concentrations are statistically reconstructed using the air flow velocity. Therefore, the detected concentration is strongly

  3. A survey of airborne HDI, HDI-based polyisocyanate and solvent concentrations in the manufacture and application of polyurethane coatings.

    PubMed

    Myer, H E; O'Block, S T; Dharmarajan, V

    1993-11-01

    This study summarizes the results of industrial hygiene surveys performed between 1979 and 1987 in paint manufacturing and application operations using polyurethane coatings containing hexamethylene diisocyanate (HDI) and HDI-based polyisocyanates (trade name Desmodur N). A total of 466 Desmodur N and 457 HDI samples were collected from 47 operations most of which were in application. The application surveys covered manufacture and refinishing of transportation vehicles, painting of large military and civilian equipment, industrial finishing operations, and maintenance and construction operations. The primary objective of the surveys was to assess the potential exposure to HDI and HDI-based polyisocyanate. In more than 60% of the surveys, concentrations of airborne organic solvents also were monitored. Isocyanates were sampled using toluene/nitroreagent in midget impingers, and solvents were collected using charcoal tubes. They were analyzed using high pressure liquid chromatography and gas chromatography, respectively. The data from these workplace situations show there is some potential for isocyanate overexposure of unprotected workers and that it is greater in spray than in nonspray operations. PMID:8256690

  4. Concentration and particle size of airborne toxic algae (brevetoxin) derived from ocean red tide events.

    PubMed

    Cheng, Yung Sung; McDonald, Jacob D; Kracko, Dean; Irvin, C Mitch; Zhou, Yue; Pierce, Richard H; Henry, Michael S; Bourdelaisa, Andrea; Naar, Jerome; Baden, Daniel G

    2005-05-15

    Red tides in the Gulf of Mexico are formed by blooms of the dinoflagellate Karenia brevis, which produces brevetoxins (PbTx). Brevetoxins can be transferred from water to air in the wind-powered whitecapped waves during red tide episodes. Inhalation exposure to marine aerosol containing PbTx causes respiratory problems. A liquid chromatograph/ tandem mass spectrometric method was developed for the detection and quantitation of several PbTxs in ambient samples collected during red tide events. This method was complemented by a previously developed antibody assay that analyzes the entire class of PbTx compounds. The method showed good linearity, accuracy, and reproducibility, allowing quantitation of PbTx compounds in the 10 pg/m3 range. Air concentrations of PbTxs and brevenal for individual samples ranged from 0.01 to 80 ng/m3. The particle size showed a single mode with a mass median diameter between 6 and 10 microm, which was consistent for all of the PbTx species that were measured. Our results imply that individual PbTxs were from the same marine aerosol or from marine aerosol that was produced from the same process. The particle size indicated the likelihood of high deposition efficiency in the respiratory tract with the majority of aerosol deposited in the upper airways and small but not insignificant deposition in the lower airways. PMID:15954221

  5. Seasonal and intradiurnal variation of airborne pollen concentrations in Bodrum, SW Turkey.

    PubMed

    Tosunoglu, Aycan; Bicakci, Adem

    2015-04-01

    An aeropalynological study was performed in Bodrum, the famous tourism center in southwestern Turkey with a Hirst-type volumetric 7-day pollen and spore trap for 2 years (2007-2008). In Bodrum, 25,099 pollen grains as a mean value belonging to 41 taxa were recorded annually during the study period, and pollen grains from woody plant taxa had the largest atmospheric contribution of 86.99% and 24 taxa. However, 17 herbaceous plant taxa constituted 12.82% of the annual total pollen count, and 0.19% were unidentified. An average annual pollen index of 22.66% was recorded in March, despite differences from year to year. The highest pollen variability of 34 taxa was recorded in April and May. Predominant pollen types belonged to Cupressaceae/Taxaceae (42.73%), Quercus (15.95%), Pinus (9.78%), Olea europaea (9.04%), Poaceae (5.50%), Betula (1.82%), Pistacia (1.74%), Morus (1.72%), Urticaceae (1.46%), and Plantago (1.28%) and generated 91.03 of the annual total. In total, 32.59% of the mean annual total pollen index was recorded in the morning, and less pollen was recorded in the evening (18.71%). Maximum pollen concentration was recorded between 11:00 and 12:00 a.m. PMID:25750068

  6. Chemical agents for conversion of chrysotile asbestos into non-hazardous materials

    DOEpatents

    Sugama, Toshifumi; Petrakis, L.

    1998-06-09

    A composition and methods are disclosed for converting a chrysotile asbestos-containing material to a non-regulated environmentally benign solid which comprises a fluoro acid decomposing agent capable of dissociating the chrysotile asbestos to non-regulated components, wherein non-regulated components are non-reactive with the environment, and a binding agent which binds the non-regulated components to form an environmentally benign solid. 2 figs.

  7. Chemical agents for conversion of chrysotile asbestos into non-hazardous materials

    DOEpatents

    Sugama, Toshifumi; Petrakis, Leon

    1998-06-09

    A composition and methods for converting a chrysotile asbestos-containing material to a non-regulated environmentally benign solid which comprises a fluoro acid decomposing agent capable of dissociating the chrysotile asbestos to non-regulated components, wherein non-regulated components are non-reactive with the environment, and a binding agent which binds the non-regulated components to form an environmentally benign solid.

  8. Airborne tunable diode laser sensor for high-precision concentration and flux measurements of carbon monoxide and methane

    NASA Technical Reports Server (NTRS)

    Sachse, G. W.; Collins, J. E., Jr.; Hill, G. F.; Wade, L. O.; Burney, L. G.; Ritter, J. A.

    1991-01-01

    An airborne tunable diode laser instrument is described that is capable of operating in two measurement modes. One mode provides high precision (0.1 percent CH4; 1 percent CO) measurements of CH4 and CO with a 5 second response time, and a second mode achieves the very fast response time that is necessary to make airborne eddy correlation flux measurements. Examples of data from atmospheric expeditions of the Global Tropospheric Experiment are presented.

  9. Evaluation of ultraviolet germicidal irradiation in reducing the airborne cultural bacteria concentrations in an elementary school in the Midwestern United States.

    PubMed

    Su, Chunxiao; Lau, Josephine; Gibbs, Shawn G

    2015-05-01

    This article describes a casestudythe authors conducted in an elementary school in the Midwest. The objective was to evaluate the performance of ultraviolet germicidal irradiation (UGVI) to reduce the bioaerosol concentration in a classroom. Two fourth grade classrooms with the same dimensions were studied. One classroom was designated as the UVGI group and the other as the control group. Two-stage Tisch culturable impactors were utilized for collecting airborne bacteria with monthly samples collected from October 2012 to January 2013. Nonparametric methods were applied and p-values smaller than .05 were deemed significant. The concentrations of airborne cultural bacteria with a smaller size (1-8 pm) and the total bacterial concentrations from the UVGI classroom were significantly lower than those of the control room in three of four sampling months. These results could provide the preliminary results necessary to determine the effectiveness of upper-room UVGI in reducing the concentration of airborne cultural bacteria in classrooms and other buildings. PMID:25985534

  10. Monitoring natural sequestration of carbon dioxide into chrysotile milling waste piles

    NASA Astrophysics Data System (ADS)

    Lemieux, J.; Beaudoin, G.; Pronost, J.; Constantin, M.; Duchesne, J.; Hebert, R.; Larachi, F.; Maldague, X.; Molson, J. W.; Tremblay, J.

    2010-12-01

    Chrysotile milling waste piles are naturally, passively and permanently stripping carbon dioxide from the atmosphere by mineral carbonation reactions at the surface and within the piles. Serpentines react with CO2 and water to yield hydrated magnesium carbonates. The reaction is exothermic and warm air vents capable of melting snow have been discovered at the upper surface of a chrysotile milling waste pile holding 130 Mt of serpentinized ultramafic rocks, accumulated since 1953, at the Black Lake mine, Québec, Canada. The warm air vents are otherwise inconspicuous at the surface of the milling waste piles. The warm air vent temperatures ranged from 7.0 to 18.5 °C from March 2009 to July 2010, as measured with a thermocouple placed in the venting area identified by infrared photography. During this time, the temperature of ambient air ranged from -13.4 to 10 °C. Measurements of CO2 concentration using a Li-Cor Li-8100 equipped with a 10-cm survey chamber yielded values as low as 10 ppm CO2 during winter 2010, which is much lower than measured atmospheric CO2, which is about 390 ppm. In order to better understand the reaction, laboratory experiments and field work are being conducted. Preliminary laboratory experiments have shown that the reaction is relatively fast and is depending strongly on humidity and CO2 supply. An experimental small-scale pile was also constructed in which the temperature, volumetric water content, gas pressure and gas composition are monitored at different depth along a cross section. The pile is 2 m high with a surface of about 100 m2 and made of fresh milling wastes. Infiltration within the pile is monitored as well as water composition running out of the pile. The observation of the carbonatation reaction in this experimental milling pile is expected to provide invaluable insights about the natural reaction taking place in the full-scale piles and may provide an estimate of captured CO2 since their construction.

  11. Characterization of chrysotile ores and samples for the presence of amphiboles from the former Carey Canadian Mine, southeastern Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Gunter, M. E.; Sanchez, M. S.

    2006-05-01

    It is now fairly well accepted that amphibole asbestos is more harmful upon inhalation than chrysotile, especially for the etiology of mesothelioma. Epidemiological evidence has shown a higher incidence of mesothelioma cases in amphibole asbestos mining districts (e.g., South Africa) as compared to chrysotile mining districts (e.g., southeastern Quebec). However, there have been some reported cases of mesothelioma from the southeastern Quebec region, and most health researchers attribute these to amphibole asbestos occurring at low-levels in some of the ores. The central portion of the district located in or near the town of Thetford Mines appears to have higher concentrations of amphiboles, and mesothelioma cases, while the mines near the edge of the district, for instance the Jeffrey mine located in the town of Asbestos southwest of Thetford Mines, have lower amphibole contents and in turn fewer cases of mesothelioma. Locally, the geology of these chrysotile-bearing ultramafic rocks contains granitic intrusions which provide the needed silica to form amphiboles. These intrusions do not appear to have occurred in the northeastern portion of the district. The medical literature almost always refers to amphiboles in these deposits as tremolites. To further test the hypothesis that the more distant mines farther from the silica-rich intrusions have lower amphibole contents, we collected a suite of samples from the former chrysotile mine operated by Carey Canadian Mines located approximately 20 miles northeast of Thetford Mines. A total of ten samples, six of which were ore samples, two in-place rock samples, and two tailings samples, were first analyzed by routine PLM (polarized light microscopy) dispersion staining and powder X-ray diffraction (XRD) methods. One sample was found to contain trace amounts of an amphibole. Quantitative XRD methods were developed and showed this one sample contained between 500 to 1,000 ppm amphibole; the detection limit of this new XRD

  12. Follow-up study of chrysotile asbestos textile workers: cohort mortality and case-control analyses.

    PubMed

    Dement, J M; Brown, D P; Okun, A

    1994-10-01

    Previous studies of mortality among white males employed in a Charleston, South Carolina asbestos textile plant using chrysotile demonstrated significant excess mortality due to asbestos-related disease and a steep exposure-response relationship for lung cancer. This cohort was further studied by adding 15 years of follow-up and including mortality among white female and black male workers. Nested case-control analyses were undertaken to further explore possible differences in lung cancer risk by textile operation as well as possible confounding by mineral oil exposures. Preliminary data for white males have been previously published. White males experienced statistically significant excess mortality due to lung cancer (standardized mortality ratio [SMR] = 2.30; confidence interval [CI] = 1.88-2.79), all causes (SMR = 1.48; CI = 1.38-158), all cancers (SMR = 1.50; CI = 1.29-1.72), diabetes mellitus (SMR = 2.05; CI = 1.18-3.33), heart disease (SMR = 1.41; CI = 1.26-1.58), cerebrovascular disease (SMR = 1.50; CI = 1.08-2.02), pneumoconiosis and other respiratory diseases (SMR = 4.10; CI = 3.10-5.31), and accidents (SMR = 1.49; CI = 1.15-1.91). Among white females, statistically significant excesses occurred for lung cancer (SMR = 2.75; CI = 2.06-3.61), all causes (SMR = 1.21; CI = 1.11-1.32), pneumoconiosis and other respiratory diseases (SMR = 2.40; CI = 1.53-3.60), and other respiratory cancers (SMR = 14.98; CI = 4.08-38.7). Among the total cohort of black males, the only statistically significant excess observed was for pneumoconiosis (SMR = 2.19; CI = 1.23-3.62). Based on historical exposure measurements at the plant, there was a positive exposure-response relationship for both lung cancer and pneumoconiosis. Data for the entire cohort demonstrate an increase in the lung cancer relative risk of 2-3% for each fiber/cc-year of cumulative chrysotile exposure. This relationship was more consistent for the white male workers. The excess risk for lung cancer among

  13. Airborne asbestos exposures associated with the installation and removal of roofing products.

    PubMed

    Lotter, Jason T; Roberts, Ben; Henshaw, John L; Pierce, Jennifer S

    2016-08-01

    Asbestos-containing roofing products were widely used throughout the 20th century, and certain products are still used in limited quantities today. Roofing products are generally considered non-friable and are not expected to release appreciable amounts of airborne asbestos fibers; however, despite the variety of roofing products that have contained asbestos over time, there are no comprehensive analyses of the exposure data associated with these products in the published literature. The objective of this study was to analyze the available data and characterize asbestos exposures associated with the installation, removal, and replacement of built-up roofing (BUR), felts, flashings, shingles, coatings, cements, and mastics under a variety of work practices. Published and unpublished literature that contained the following information was included in the analysis: (1) airborne fiber concentrations determined by PCM; (2) a description of the product(s) used; and (3) a description of the task(s) performed. More than 800 personal air samples from 12 studies performed between 1982 and 2010 were identified which fit the inclusion criteria. The findings indicate that short-term and full-shift exposures from the use of asbestos-containing roofing products were typically well below applicable occupational exposure limits. Additionally, the cumulative exposures associated with roofing work would be well below published chrysotile no-observed-adverse-effect-levels (NOAELs) for asbestos-related diseases. PMID:27124394

  14. Adsorption of bovine serum albumin onto synthetic Fe-doped geomimetic chrysotile

    PubMed Central

    Adamiano, Alessio; Lesci, Isidoro Giorgio; Fabbri, Daniele; Roveri, Norberto

    2015-01-01

    Synthetic stoichiometric and Fe-doped geomimetic chrysotile nanocrystals represent a reference standard to investigate the health hazard associated with mineral asbestos fibres. Experimental evidence suggests that the generation of reactive oxygen species and other radicals, catalysed by iron ions at the fibre surface, plays an important role in asbestos-induced cytotoxicity and genotoxicity. In this study, structural modification of bovine serum albumin (BSA) adsorbed onto synthetic chrysotile doped with different amounts of Fe has been investigated by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and analytical pyrolysis coupled with gas chromatography–mass spectrometry. FT-IR data evidenced a marked increase in disordered structures like random coil and β-turn of BSA–nanocrystal adduct with 0.52 wt% of Fe doped. The TGA profile of the BSA revealed that its interaction with the synthetic chrysotile surface was strongly affected by the substitution of Fe into the chrysotile structure. The 2,5-diketopiperazine yields, formed upon thermal degradation of the polypeptide chain (pyrolysis–gas chromatography), changed when the BSA was adsorbed on the nanofibres. In general, results suggested that minute amount (less than 1 wt%) of Fe doping in chrysotile affected the protein–nanofibre interactions, supporting the role that this element may play in asbestos toxicity. The catalytic role of iron and the consequent unfolding of protein due to the structural surface modification of nanofibres were also evaluated. PMID:26018963

  15. Novel selective dyeing method for chrysotile asbestos detection in concrete materials.

    PubMed

    Oke, Yoshihiko; Yamasaki, Nakamichi; Amamoto, Go Y; Sasaki, Kazuhiro; Maeta, Naomi; Fujimaki, Hirokazu; Hashida, Toshiyuki

    2008-03-01

    There are a tremendous number of asbestos-containing buildings without any surveys on the presence of asbestos because of the difficulty to detect asbestos in building materials simply and quickly, although a great deal of worldwide effort was put into removing asbestos of which inhalation causes serious diseases. In this study, we newly developed a simple dyeing method to detect chrysotile asbestos, the most commonly used type of asbestos, in asbestos-cement composite materials using magnesium-chelating organic dyes. As an essential process for selective dyeing of chrysotile asbestos, special pretreatment with a calcium-chelating agent was developed to prevent the dyes from reacting with calcium, which is the major component of concrete materials. Our developed selective dyeing method was shown to possess sufficient sensitivity for detecting chrysotile asbestos in an amount greater than 0.1 mass% in concrete specimens, and there was an approximately linear relationship between the area fraction of dyed spots and the mass fraction of chrysotile asbestos. Our results may provide a basis for further development of a simple on-site detection method for chrysotile asbestos in building materials and may facilitate the progress of control and removal of asbestos in the environment. PMID:18441814

  16. Occupational exposure to chrysotile asbestos and cancer risk: a review of the amphibole hypothesis.

    PubMed Central

    Stayner, L T; Dankovic, D A; Lemen, R A

    1996-01-01

    OBJECTIVES. This article examines the credibility and policy implications of the "amphibole hypothesis," which postulates that (1) the mesotheliomas observed among workers exposed to chrysotile asbestos may be explained by confounding exposures to amphiboles, and (2) chrysotile may have lower carcinogenic potency than amphiboles. METHODS. A critical review was conducted of the lung burden, epidemiologic, toxicologic, and mechanistic studies that provide the basis for the amphibole hypothesis. RESULTS. Mechanistic and lung burden studies do not provide convincing evidence for the amphibole hypothesis. Toxicologic and epidemiologic studies provide strong evidence that chrysotile is associated with an increased risk of lung cancer and mesothelioma. Chrysotile may be less potent than some amphiboles for inducing mesotheliomas, but there is little evidence to indicate lower lung cancer risk. CONCLUSIONS. Given the evidence of a significant lung cancer risk, the lack of conclusive evidence for the amphibole hypothesis, and the fact that workers are generally exposed to a mixture of fibers, we conclude that it is prudent to treat chrysotile with virtually the same level of concern as the amphibole forms of asbestos. PMID:8633733

  17. Retrieval of Atmospheric CO2 Concentration above Clouds and Cloud Top Pressure from Airborne Lidar Measurements during ASCENDS Science Campaigns

    NASA Astrophysics Data System (ADS)

    Mao, J.; Ramanathan, A. K.; Rodriguez, M.; Allan, G. R.; Hasselbrack, W. E.; Abshire, J. B.; Riris, H.; Kawa, S. R.

    2014-12-01

    NASA Goddard is developing an integrated-path, differential absorption (IPDA) lidar approach to measure atmospheric CO2 concentrations from space as a candidate for NASA's ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission. The approach uses pulsed lasers to measure both CO2 and O2 absorption simultaneously in the vertical path to the surface at a number of wavelengths across a CO2 line at 1572.335 nm and an O2 line doublet near 764.7 nm. Measurements of time-resolved laser backscatter profiles from the atmosphere allow the technique to estimate column CO2 and O2 number density and range to cloud tops in addition to those to the ground. This allows retrievals of CO2 column above clouds and cloud top pressure, and all-sky measurement capability from space. This additional information can be used to evaluate atmospheric transport processes and other remote sensing carbon data in the free atmosphere, improve carbon data assimilation in models and help global and regional carbon flux estimates. We show some preliminary results of this capability using airborne lidar measurements from the summers of 2011 and 2014 ASCENDS science campaigns. These show simultaneous retrievals of CO2 and O2 column densities for laser returns from low-level marine stratus clouds in the west coast of California. This demonstrates the supplemental capability of the future space carbon mission to measure CO2 above clouds, which is valuable particularly for the areas with persistent cloud covers, e.g, tropical ITCZ, west coasts of continents with marine layered clouds and southern ocean with highest occurrence of low-level clouds, where underneath carbon cycles are active but passive remote sensing techniques using the reflected short wave sunlight are unable to measure accurately due to cloud scattering effect. We exercise cloud top pressure retrieval from O2 absorption measurements during the flights over the low-level marine stratus cloud decks, which is one of

  18. The use of an experimental room for monitoring of airborne concentrations of microorganisms, glass fibers, and total particles

    SciTech Connect

    Buttner, M.P.; Stetzenbach, L.D.

    1996-12-31

    An experimental room was used as a microcosm for studies of airborne particles and microorganisms in indoor environments. The interior of the room measures 4 by 4 by 2.2 m high and has a hardwood floor and the walls and ceiling are sheetrocked and coated with interior latex paint. Exterior walls are 11.4-cm thick plywood panels consisting of two outer sections of plywood insulated with fiber glass batts. The ceiling is of similar construction with 17.1-cm thick panels. Attached to the room entrance is an anteroom equipped with a HEPA-filtered air shower to reduce mixing of air resulting from entering and exiting during experiments. The room is equipped with a computer-controlled heating, ventilation, and cooling system. Temperature, relative humidity, air flow, and room pressure can be continuously monitored by probes located in the room and air handling system components. Several research projects have been conducted using this room including monitoring the potential for airborne glass fibers released from rigid fibrous ductboard, comparisons of commercially available samplers for monitoring of airborne fungal spores, and a study on the efficacy of vacuum bags to minimize dispersal of particles, including fungal spores from fungal-contaminated carpet. During studies designed to monitor airborne fiberglass, air samples were taken in the room serviced by new rigid fibrous glass ductwork, and the results were compared to those obtained in the room with bare metal ductwork installed. Monitoring of airborne fungal spores using the Andersen six-stage sampler, the high flow Spiral Biotech sampler, the Biotest RCS Plus sampler, and the Burkard spore trap sampler was performed following the release of Penicillium spores into the room through the supply register. Dispersal of carpet-associated particles and fungal spores was measured after vacuuming using conventional cellulose vacuum bags in comparison to recently developed bags.

  19. Concentrations of trace elements and compounds in the airborne suspended particulate matter in Cleveland, Ohio, from August 1971 to August 1972 and their dependence on wind direction: Complete data listing and concentration roses

    NASA Technical Reports Server (NTRS)

    King, R. B.; Neustadter, H. E.

    1976-01-01

    Concentrations of 75 chemical constituents in the airborne particulate matter were measured in Cleveland, Ohio during 1971 and 1972. Daily values, maxima, geometric means and their standard deviations covering a 1-year period (45 to 50 sampling days) at each of 16 sites are presented on microfiche for 60 elements, and for a lesser number of days for 10 polycyclic aromatic hydrocarbon compounds (PAH), the aliphatic hydrocarbon compounds (AH) as a group and carbon. In addition, concentration roses showing directional properties are presented for 39 elements, 10 PAH and the AH as a group. The elements (except carbon) are shown both in terms of concentration and percentage of the suspended particulate matter.

  20. Continuous exposure to chrysotile asbestos can cause transformation of human mesothelial cells via HMGB1 and TNF-α signaling.

    PubMed

    Qi, Fang; Okimoto, Gordon; Jube, Sandro; Napolitano, Andrea; Pass, Harvey I; Laczko, Rozalia; Demay, Richard M; Khan, Ghazal; Tiirikainen, Maarit; Rinaudo, Caterina; Croce, Alessandro; Yang, Haining; Gaudino, Giovanni; Carbone, Michele

    2013-11-01

    Malignant mesothelioma is strongly associated with asbestos exposure. Among asbestos fibers, crocidolite is considered the most and chrysotile the least oncogenic. Chrysotile accounts for more than 90% of the asbestos used worldwide, but its capacity to induce malignant mesothelioma is still debated. We found that chrysotile and crocidolite exposures have similar effects on human mesothelial cells. Morphological and molecular alterations suggestive of epithelial-mesenchymal transition, such as E-cadherin down-regulation and β-catenin phosphorylation followed by nuclear translocation, were induced by both chrysotile and crocidolite. Gene expression profiling revealed high-mobility group box-1 protein (HMGB1) as a key regulator of the transcriptional alterations induced by both types of asbestos. Crocidolite and chrysotile induced differential expression of 438 out of 28,869 genes interrogated by oligonucleotide microarrays. Out of these 438 genes, 57 were associated with inflammatory and immune response and cancer, and 14 were HMGB1 targeted genes. Crocidolite-induced gene alterations were sustained, whereas chrysotile-induced gene alterations returned to background levels within 5 weeks. Similarly, HMGB1 release in vivo progressively increased for 10 or more weeks after crocidolite exposure, but returned to background levels within 8 weeks after chrysotile exposure. Continuous administration of chrysotile was required for sustained high serum levels of HMGB1. These data support the hypothesis that differences in biopersistence influence the biological activities of these two asbestos fibers. PMID:24160326

  1. Continuous Exposure to Chrysotile Asbestos Can Cause Transformation of Human Mesothelial Cells via HMGB1 and TNF-α Signaling

    PubMed Central

    Qi, Fang; Okimoto, Gordon; Jube, Sandro; Napolitano, Andrea; Pass, Harvey I.; Laczko, Rozalia; DeMay, Richard M.; Khan, Ghazal; Tiirikainen, Maarit; Rinaudo, Caterina; Croce, Alessandro; Yang, Haining; Gaudino, Giovanni; Carbone, Michele

    2014-01-01

    Malignant mesothelioma is strongly associated with asbestos exposure. Among asbestos fibers, crocidolite is considered the most and chrysotile the least oncogenic. Chrysotile accounts for more than 90% of the asbestos used worldwide, but its capacity to induce malignant mesothelioma is still debated. We found that chrysotile and crocidolite exposures have similar effects on human mesothelial cells. Morphological and molecular alterations suggestive of epithelial–mesenchymal transition, such as E-cadherin down-regulation and β-catenin phosphorylation followed by nuclear translocation, were induced by both chrysotile and crocidolite. Gene expression profiling revealed high-mobility group box-1 protein (HMGB1) as a key regulator of the transcriptional alterations induced by both types of asbestos. Crocidolite and chrysotile induced differential expression of 438 out of 28,869 genes interrogated by oligonucleotide microarrays. Out of these 438 genes, 57 were associated with inflammatory and immune response and cancer, and 14 were HMGB1 targeted genes. Crocidolite-induced gene alterations were sustained, whereas chrysotile-induced gene alterations returned to background levels within 5 weeks. Similarly, HMGB1 release in vivo progressively increased for 10 or more weeks after crocidolite exposure, but returned to background levels within 8 weeks after chrysotile exposure. Continuous administration of chrysotile was required for sustained high serum levels of HMGB1. These data support the hypothesis that differences in biopersistence influence the biological activities of these two asbestos fibers. PMID:24160326

  2. Examination of the Thermal Transformation of Chrysotile by Using Dispersion Staining and Conventional X-ray Diffraction Techniques

    NASA Astrophysics Data System (ADS)

    Crummett, C. D.; Candela, P. A.; Wylie, A. G.; Earnest, D. J.

    2004-12-01

    Chrysotile has been used industrially as a component of refractory products, and in friction products, such as brake linings. Examining the decomposition or transformation of chrysotile as a function of time and temperature will help clarify the characteristics of particulates released during processes such as automotive braking. Previous studies have reported that the thermal treatment of chrysotile alters both its surface and structure, resulting in deviations from its natural properties, possibly reducing its biological activity (Langer, 2003: Reg Tox Pharm, v38, p71). In past studies, the nonequilibrium thermal decomposition of chrysotile has been investigated by using static dehydration, X-ray diffraction, differential thermal analysis, and thermogravimetric analysis. These studies suggest that the thermal transformation of chrysotile follows a two step sequence of dehydroxylation/dehydration and recrystallization where (1) chrysotile yields forsterite + silica + water with (2) forsterite + silica later forming enstatite (Ball and Taylor, 1963: Mineral. Mag. v33, p467, Brindley and Hayami, 1965: Mineral. Mag. v35, p189). In this research the decomposition of chrysotile from Thetford Quebec was studied. Samples were heated isothermally in air at temperatures from 200° C to 1000° C. After heating for up to 24 hours the refractive indices of remaining chrysotile fibers were measured by using dispersion staining. In addition, reaction products were identified by optical methods, electron probe microanalysis, and X-ray diffraction performed after the termination of the experiment. Preliminary results show that there is no change in optical properties of chrysotile heated to 400° C for 24 hours. From 400° C to 575° C for 24 hours, the index of refraction increases parallel to the length of the fiber from 1.552 to 1.560. From 400° C to 575° C for 24 hours, the index of refraction perpendicular to the length of the fiber varies irregularly from 1.538-1.548. The

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

    PubMed

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

    2006-07-01

    Five test sessions were conducted to assess asbestos exposure during the removal or installation of asbestos-containing gaskets on vehicles. All testing took place within an operative automotive repair facility involving passenger cars and a pickup truck ranging in vintage from late 1960s through 1970s. A professional mechanic performed all shop work including engine disassembly and reassembly, gasket manipulation and parts cleaning. Bulk sample analysis of removed gaskets through polarized light microscopy (PLM) revealed asbestos fiber concentrations ranging between 0 and 75%. Personal and area air samples were collected and analyzed using National Institute of Occupational Safety Health (NIOSH) methods 7400 [phase contrast microscopy (PCM)] and 7402 [transmission electron microscopy (TEM)]. Among all air samples collected, approximately 21% (n = 11) contained chrysotile fibers. The mean PCM and phase contrast microscopy equivalent (PCME) 8-h time weighted average (TWA) concentrations for these samples were 0.0031 fibers/cubic centimeters (f/cc) and 0.0017 f/cc, respectively. Based on these findings, automobile mechanics who worked with asbestos-containing gaskets may have been exposed to concentrations of airborne asbestos concentrations approximately 100 times lower than the current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) of 0.1 f/cc. PMID:16730109

  4. Analysis of palladium concentrations in airborne particulate matter with reductive co-precipitation, He collision gas, and ID-ICP-Q-MS.

    PubMed

    Alsenz, H; Zereini, F; Wiseman, C L S; Püttmann, W

    2009-11-01

    The concentration of platinum group elements (PGE) in the environment has increased significantly in the last 20 years mainly due to their use as catalysts in automotive catalytic converters. The quantitation of these metals in different environmental compartments is, however, challenging due to their very low concentrations and the presence of interfering matrix constituents when inductively coupled plasma-mass spectrometry (ICP-MS) is used for analysis. Previously, the research focus was on the analysis of platinum (Pt) and rhodium (Rh). However, due to the increasing use of palladium (Pd) in automotive catalytic converters, quantitation of this element in airborne particulate matter (PM) is also needed. Compared to Pt and Rh, measurements of Pd using ICP-MS are plagued by greater molecular interferences arising from elements such as copper (Cu), zinc (Zn) strontium (Sr), yttrium (Y), and zirconium (Zr). The aim of this study was to evaluate the applicability of reductive co-precipitation procedures using both mercury (Hg) and tellurium (Te) for the pre-concentration of Pd from airborne PM. Furthermore, helium (He) was tested as a collision gas for isotope dilution-inductively coupled plasma-quadrupole-mass spectrometry (ID-ICP-Q-MS) to measure Pd in the Hg and Te precipitates. Airborne PM samples (PM10) were collected from Neuglobsow (Brandenburg, north-eastern Germany) and Deuselbach (Rhineland-Palatinate, south-western Germany), considered to represent background levels, and from the city Frankfurt am Main (Hesse, Germany), a high-traffic area. Samples were first digested with aqua regia in a high-pressure asher (HPA) at 320 degrees C and 130 bar prior to the application of reductive co-precipitation procedures. The method was validated with road dust reference material BCR-723 and the CANMET-CCRMP reference material TDB-1 and WPR-1. In airborne PM collected at the background areas Neuglobsow and Deuselbach, Pd was detected with median concentrations values of

  5. [Occupational lung diseases caused by exposure to chrysotile asbestos dust and the preventive measures].

    PubMed

    Pliukhin, A E; Burmistrova, T B

    2014-01-01

    To reveal major principles in system of occupational lung diseases prevention among workers engaged into extraction and usage of chrysotile asbestos, the authors specified main criteria for diagnosis of asbestos-related pulmonary diseases and signs of exposure to chrysotile dust, with identification of risk groups for occupational diseases development. The authors formulated main principles of prevention and rehabilitation for workers with asbestos-related pulmonary diseases. Special attention was paid to harmonization of all medical and technical measures aimed at prevention and liquidation of occupational asbestos-related diseases. PMID:25282798

  6. Development of a new methodology for the retrieval of in-situ stratospheric trace gases concentration from airborne limb-absorption measurements

    NASA Astrophysics Data System (ADS)

    Petritoli, Andrea; Giovanelli, Giorgio; Ravegnani, Fabrizio; Bortoli, Daniele; Kostadinov, Ivan K.; Castelli, Elisa; Bonafe, U.; Oulanovsky, A.; Yushkov, Vladimir

    2002-01-01

    The UV-Vis DOAS spectrometer GASCOD/A4p (Gas Analyzer Spectrometer Correlating Optical Differences, Airborne version) was installed on board the stratospheric Geophysica aircraft during the APE-THESEO and APE-GAIA campaign in February-March and September-October 1999 respectively. The instrument is provided by five input windows, three of which measure scattered solar radiation from the zenith and from two horizontal windows, 90 degree(s) away from the zenith to perform limb-absorption measurements. Spectra from 290 to 700 nm were processed through DOAS technique to obtain trace gases column amounts. Data from horizontal windows, which are performed for the first time from an airborne spectrometer, are used to retrieve an average concentration of the gases along a characteristic length of the line of sight. An atmospheric Air Mass Factor model (AMEFCO) is used to calculate the probability density function and the characteristic length used to reduce the slant column amounts to in-situ concentration values. The validation of the method is performed through a comparison of the values obtained, with a in-situ chemiluminescent ozone analyzer (FOZAN) which performed synchronous measurements on board Geophysica aircraft. Data from the APE-GAIA campaign was presented and discussed.

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

    SciTech Connect

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

    1998-07-01

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

  8. Strength of chrysotile-serpentinite gouge under hydrothermal conditions: Can it explain a weak San Andreas fault?

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, D.A.; Summers, R.; Shengli, M.; Byerlee, J.D.

    1996-01-01

    Chrysotile-bearing serpentinite is a constituent of the San Andreas fault zone in central and northern California. At room temperature, chrysotile gouge has a very low coefficient of friction (?? ??? 0.2), raising the possibility that under hydrothermal conditions ?? might be reduced sufficiently (to ???0.1) to explain the apparent weakness of the fault. To test this hypothesis, we measured the frictional strength of a pure chrysotile gouge at temperatures to 290??C and axial-shortening velocities as low as 0.001 ??m/s. As temperature increases to ???100??C, the strength of the chrysotile gouge decreases slightly at low velocities, but at temperatures ???200??C, it is substantially stronger and essentially independent of velocity at the lowest velocities tested. We estimate that pure chrysotile gouge at hydrostatic fluid pressure and appropriate temperatures would have shear strength averaged over a depth of 14 km of 50 MPa. Thus, on the sole basis of its strength, chrysotile cannot be the cause of a weak San Andreas fault. However, chrysotile may also contribute to low fault strength by forming mineral seals that promote the development of high fluid pressures.

  9. On the mechanism of cell internalization of chrysotile fibers: An immunocytochemical and ultrastructural study

    SciTech Connect

    Malorni, W.; Iosi, F.; Falchi, M.; Donelli, G. )

    1990-08-01

    Human breast carcinoma cells (CG5) and human laryngeal carcinoma cells (HEp-2) were exposed to 10 and 50 {mu}ml (about 5 {mu}m) chrysotile asbestos fibers. Morphological and ultrastructural changes were evaluated by means of immunocytochemistry and by scanning and transmission electron microscopy. The authors attention was focused on the mechanisms of cell internalization and on transport of chrysotile fibers. The fibers appeared to penetrate the cell cytoplasm and to be translocated in proximity of the nucleus. Small chrysotile fibers could also be found inside the nucleus of interphase cells. Involvement of the main cytoskeletal components, i.e., microfilaments, intermediate filaments, and microtubules, in the cytotoxicity of chrysotile fibers was also evaluated. Their findings suggest that after fiber penetration, a rearrangement of the cytoskeletal apparatus occurs. It has also been observed that small fibers remain associated with the cytoskeletal framework, which can thus play a role in asbestos intracytoplasmic translocation in epithelial cells. Furthermore, after the cell has completely recovered its morphology, fiber internalization ultimately seems to lead to the formation of giant multinucleated cells. These data could be indicative of an interaction occurring between asbestos fibers and the normal mitotic process.

  10. Multipolar mitosis and aneuploidy after chrysotile treatment: a consequence of abscission failure and cytokinesis regression

    PubMed Central

    Cortez, Beatriz Araujo; Teixeira, Paula Rezende; Redick, Sambra; Doxsey, Stephen; Machado-Santelli, Glaucia Maria

    2016-01-01

    Chrysotile, like other types of asbestos, has been associated with mesothelioma, lung cancer and asbestosis. However, the cellular abnormalities induced by these fibers involved in cancer development have not been elucidated yet. Previous works show that chrysotile fibers induce features of cancer cells, such as aneuploidy, multinucleation and multipolar mitosis. In the present study, normal and cancer derived human cell lines were treated with chrysotile and the cellular and molecular mechanisms related to generation of aneuploid cells was elucidated. The first alteration observed was cytokinesis regression, the main cause of multinucleated cells formation and centrosome amplification. The multinucleated cells formed after cytokinesis regression were able to progress through cell cycle and generated aneuploid cells after abnormal mitosis. To understand the process of cytokinesis regression, localization of cytokinetic proteins was investigated. It was observed mislocalization of Anillin, Aurora B, Septin 9 and Alix in the intercellular bridge, and no determination of secondary constriction and abscission sites. Fiber treatment also led to overexpression of genes related to cancer, cytokinesis and cell cycle. The results show that chrysotile fibers induce cellular and molecular alterations in normal and tumor cells that have been related to cancer initiation and progression, and that tetraploidization and aneuploid cell formation are striking events after fiber internalization, which could generate a favorable context to cancer development. PMID:26788989

  11. Coinhibition of viral interferon induction by benzo(a)pyrene and chrysotile asbestos

    SciTech Connect

    Hahon, N.; Booth, J.A.

    1986-06-01

    Benzo(a)pyrene (B(a)P) and its noncarcinogenic analog, benzo(e)pyrene (B(e)P), each in combination with chrysotile, were studied for their inhibitory effects on interferon (IFN) induction by influenza virus in rhesus monkey kidney (LLC-MK/sub 2/) cell monolayers. B(a)P alone had no adverse effect on IFN induction; however, from 60 to 70% inhibition of IFN production occurred when B(a)P was enzymatically activated by rat liver S9. Chrysotile's inhibitory effect on the IFN process was similar in magnitude to that of activated B(a)P. The combination of activated B(a)P with chrysotile resulted in coinhibition of IFN induction which significantly exceeded the inhibitory activity of the reagents tested alone or in other combinations. B(e)P alone or with S9 neither affected IFN induction nor was it capable of further enhancing chrysotile's inhibition of IFN synthesis. These findings provide further evidence of enhanced deleterious action by the combination of asbestos and activated B(a)P on a biological defense mechanism and further support the discriminatory power and credibility of the inhibition IFN induction assay for evaluating potential carcinogens.

  12. Multipolar mitosis and aneuploidy after chrysotile treatment: a consequence of abscission failure and cytokinesis regression.

    PubMed

    Cortez, Beatriz Araujo; Rezende-Teixeira, Paula; Redick, Sambra; Doxsey, Stephen; Machado-Santelli, Glaucia Maria

    2016-02-23

    Chrysotile, like other types of asbestos, has been associated with mesothelioma, lung cancer and asbestosis. However, the cellular abnormalities induced by these fibers involved in cancer development have not been elucidated yet. Previous works show that chrysotile fibers induce features of cancer cells, such as aneuploidy, multinucleation and multipolar mitosis. In the present study, normal and cancer derived human cell lines were treated with chrysotile and the cellular and molecular mechanisms related to generation of aneuploid cells was elucidated. The first alteration observed was cytokinesis regression, the main cause of multinucleated cells formation and centrosome amplification. The multinucleated cells formed after cytokinesis regression were able to progress through cell cycle and generated aneuploid cells after abnormal mitosis. To understand the process of cytokinesis regression, localization of cytokinetic proteins was investigated. It was observed mislocalization of Anillin, Aurora B, Septin 9 and Alix in the intercellular bridge, and no determination of secondary constriction and abscission sites. Fiber treatment also led to overexpression of genes related to cancer, cytokinesis and cell cycle. The results show that chrysotile fibers induce cellular and molecular alterations in normal and tumor cells that have been related to cancer initiation and progression, and that tetraploidization and aneuploid cell formation are striking events after fiber internalization, which could generate a favorable context to cancer development. PMID:26788989

  13. Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

    NASA Astrophysics Data System (ADS)

    Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

    2015-04-01

    Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

  14. Mapping methane concentrations from a controlled release experiment using the next generation Airborne Visible/Infrared Imaging Spectrometer (AVIRISng)

    NASA Astrophysics Data System (ADS)

    Thorpe, A. K.; Frankenberg, C.; Roberts, D. A.; Aubrey, A. D.; Green, R. O.; Hulley, G. C.; Hook, S. J.

    2014-12-01

    Airborne imaging spectrometers like the next generation Airborne Visible/Infrared Imaging Spectrometer (AVIRISng) are well suited for monitoring local methane sources by covering large regions with the high spatial resolution necessary to resolve emissions. As part of a field campaign with controlled methane releases at the Rocky Mountain Oilfield Testing Center (RMOTC), a number of methane plumes were clearly visible at multiple flux rates and flight altitudes. Images of plumes appeared consistent with wind directions measured at ground stations and were present for fluxes as low as 14.2 cubic meters of methane per hour, equivalent to 0.09 kt/year. Direct comparison of results from AVIRISng and plume dispersion models is ongoing and will be used to assess the potential of constraining emission fluxes using AVIRISng. Methane plumes observed at RMOTC with the Hyperspectral Thermal Emission Spectrometer (HyTES) will also be presented. This controlled release experiment was used to determine the methane sensitivity of AVIRISng and inform sensor design for future imaging spectrometers that could constrain natural and anthropogenic methane emissions on local and regional scales. Imaging spectrometers permit direct attribution of emissions to individual point sources which is particularly useful given the large uncertainties associated with anthropogenic emissions, including industrial point source emissions and fugitive methane from the oil and gas industry. Figure caption: a. AVIRISng true color image indicating tube trailer (TT), meteorological tower (MT), and release point (RP). b. Prominent methane plume and measured enhancements for 70.8 cubic meters per hour methane flux is consistent with wind speed and direction (see arrow) measured by meteorological tower. A linear transect is shown in red and corresponds to enhancements shown in c. d. True color image showing release point (RP). e. Smaller methane plume for 14.2 cubic meters per hour flux. f. Methane

  15. Airborne concentrations, skin contamination, and urinary metabolite excretion of polycyclic aromatic hydrocarbons among paving workers exposed to coal tar derived road tars

    SciTech Connect

    Jongeneelen, F.J.; Scheepers, P.T.; Groenendijk, A.; Van Aerts, L.A.; Anzion, R.B.; Bos, R.P.; Veenstra, S.J.

    1988-12-01

    The exposure of surface dressing workers to polycyclic aromatic hydrocarbons (PAH) was studied. Four different paving sites, at which coal tar-containing binders were applied, were selected as work sites with high exposure levels of PAH. Breathing zone airborne particulates, contamination of the skin with PAH, and 1-hydroxypyrene in urine of the workers involved in chip sealing were determined. Substantial concentrations of cyclohexane-soluble airborne particulate matter were found (GM = 0.2 mg/m3, n = 28). Skin contamination was determined using two different methods: with exposure pads and by hand washing. Pads were mounted on several parts of the body: wrist, elbow, neck, shoulder, and ankle. The pads located on the wrist appeared to be the most contaminated (pyrene: GM = 22 ng/1.77 cm2, n = 40). The end-of-shift hand washing showed that the hands of the workers were contaminated with PAH (pyrene: GM = 70 micrograms, n = 35). Preshift hand washing showed far lower, but detectable, quantities of PAH on workers' hands (pyrene: GM = 5 micrograms, n = 35). Enhanced levels of urinary 1-hydroxypyrene among the workers were found. The highest levels were found in the end-of-shift urine samples. Correlations between the pyrene exposure variables were studied. Significant positive correlations were found between pyrene on the wrist pad versus end-of-shift urinary 1-hydroxypyrene; between pyrene on the hands versus end-of-shift urinary 1-hydroxypyrene; and between the two different skin contamination variables.

  16. Airborne polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs), and dechlorane plus (DP) in concentrated vehicle parking areas.

    PubMed

    Li, Huiru; Liu, Hehuan; Mo, Ligui; Sheng, Guoying; Fu, Jiamo; Peng, Ping'an

    2016-06-01

    This study investigated polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs), and dechlorane plus (DP) in air around three concentrated vehicle parking areas (underground, indoor, and outdoor) in a metropolitan of South China. The parking areas showed higher concentrations of PBDEs, PBDD/Fs, and DP than their adjacent urban area or distinct congener/isomer profiles, which indicate their local emission sources. The highest PBDE and DP concentrations were found in the outdoor parking lot, which might be related to the heating effect of direct sunlight exposure. Multi-linear regression analysis results suggest that deca-BDEs without noticeable transformation contributed most to airborne PBDEs in all studied areas, followed by penta-BDEs. The statistically lower anti-DP fractions in the urban area than that of commercial product signified its degradation/transformation during transportation. Neither PBDEs nor vehicle exhaust contributed much to airborne PBDD/Fs in the parking areas. There were 68.1-100 % of PBDEs, PBDD/Fs, and DP associated with particles. Logarithms of gas-particle distribution coefficients (K ps) of PBDEs were significantly linear-correlated with those of their sub-cooled vapor pressures (p Ls) and octanol-air partition coefficients (K OAs) in all studied areas. The daily inhalation doses of PBDEs, DP, and PBDD/Fs were individually estimated as 89.7-10,741, 2.05-39.4, and 0.12-4.17 pg kg(-1) day(-1) for employees in the parking areas via Monte Carlo simulation. PMID:26884244

  17. A method for computing the damage level due to the exposure to an airborne chemical with a time-varying concentration.

    PubMed

    Acquesta, Alejandro D; Sánchez, Erica Yanina; Porta, Andres; Jacovkis, Pablo M

    2011-09-01

    The calculation of damage level due to the exposure to a toxic cloud is usually not included in most popular software, or it is included using techniques that do not take into account the variation in concentration over a period of time. In this work, a method is introduced for calculating the temporal evolution of the potential damage level and to obtain a more precise and descriptive estimation of this level. The proposed goal is: to estimate the maximum and minimum damage level experienced by a population due to the exposure to an airborne chemical with a time-varying concentration; to be able to assess the damage level experienced in a progressive way, as the exposure to the airborne chemical occurs. The method relies on transformations of time-concentration pairs on a continuum of damage level curves based on the available guideline levels, obtaining maximum and minimum approximations of the expected damage level for any exposure duration. Consequently, applying this method to transport model output data and demographic information, damage evolution in relation to time and space can be predicted, as well as its effect on the local population, which enables the determination of threat zones. The comparison between the proposed method and the current (Spanish and ALOHA) ones showed that the former can offer a more precise estimation and a more descriptive approach of the potential damage level. This method can be used by atmospheric dispersion models to compute damage level and graphically display the regions exposed to each guideline level on area maps. PMID:21395635

  18. Emission of airborne fibers from mechanically impacted asbestos-cement sheets and concentration of fibrous aerosol in the home environment in Upper Silesia, Poland.

    PubMed

    Pastuszka, Jozef S

    2009-03-15

    The emission rate ((S)) of fibers released from asbestos-cement plates due to mechanical impact was determined experimentally. The emission rate has been defined as a number of fibers (F) emitted from a unit area (m(2)) due to the unit impact energy (J). For fiber longer than 5 microm the obtained surface emission factor for asbestos-cement slabs slightly increased with deteriorating surface, changing from 2.7 x 10(3) F/(m(2)J) for samples with a very good surface to 6.9 x 10(3) F/(m(2)J) for the sample with worn surface (in the SI system the emission rate unit should be (m(-2)J(-1))). The emission rate for short fibers (L < or = 5 microm) was little higher compared with emission of long fibers for all studied asbestos materials. The averaged emission rate for all studied samples was about 5000 and 6000 of long and short fibers, respectively, emitted per square meter (because of the impact energy equal to 1J). The dominating population of emitted fibers ranged from 2 to around 8 microm in length. The second part of this work constitutes the report on the concentration of airborne respirable fibers, and their length distribution in two different groups of homes in Upper Silesia, Poland. Mean concentration level of the respirable fibers, longer than 5 microm, was found to be 850 F/m(3) (according to the SI system the fiber concentration unit is (m(-3))) in the buildings covered with asbestos-cement sheets and 280 F/m(3) in the homes without asbestos-containing facades, located away from other asbestos sources. Although the laboratory and field measurements have been made by using the MIE Laser Fiber Monitor FM-7400 only, the obtained results indicate that the outdoor asbestos-cement building facades are significant sources of airborne fibers inside the dwellings in Upper Silesian towns. PMID:18692307

  19. Assessment and determinants of airborne bacterial and fungal concentrations in different indoor environments: Homes, child day-care centres, primary schools and elderly care centres

    NASA Astrophysics Data System (ADS)

    Madureira, Joana; Paciência, Inês; Rufo, João Cavaleiro; Pereira, Cristiana; Teixeira, João Paulo; de Oliveira Fernandes, Eduardo

    2015-05-01

    Until now the influence of risk factors resulting from exposure to biological agents in indoor air has been far less studied than outdoor pollution; therefore the uncertainty of health risks, and how to effectively prevent these, remains. This study aimed (i) to quantify airborne cultivable bacterial and fungal concentrations in four different types of indoor environment as well as to identify the recovered fungi; (ii) to assess the impact of outdoor bacterial and fungal concentrations on indoor air; (iii) to investigate the influence of carbon dioxide (CO2), temperature and relative humidity on bacterial and fungal concentrations; and (iv) to estimate bacterial and fungal dose rate for children (3-5 years old and 8-10 years old) in comparison with the elderly. Air samples were collected in 68 homes, 9 child day-care centres, 20 primary schools and 22 elderly care centres, in a total of 264 rooms with a microbiological air sampler and using tryptic soy agar and malt extract agar culture media for bacteria and fungi growth, respectively. For each building, one outdoor representative location were identified and simultaneously studied. The results showed that child day-care centres were the indoor microenvironment with the highest median bacterial and fungal concentrations (3870 CFU/m3 and 415 CFU/m3, respectively), whereas the lowest median concentrations were observed in elderly care centres (222 CFU/m3 and 180 CFU/m3, respectively). Indoor bacterial concentrations were significantly higher than outdoor concentrations (p < 0.05); whereas the indoor/outdoor ratios for the obtained fungal concentrations were approximately around the unit. Indoor CO2 levels were associated with the bacterial concentration, probably due to occupancy and insufficient ventilation. Penicillium and Cladosporium were the most frequently occurring fungi. Children's had two times higher dose rate to biological pollutants when compared to adult individuals. Thus, due to children

  20. Relationships between airborne fungal spore concentration of Cladosporium and the summer climate at two sites in Britain

    NASA Astrophysics Data System (ADS)

    Hollins, P. D.; Kettlewell, P. S.; Atkinson, M. D.; Stephenson, D. B.; Corden, J. M.; Millington, W. M.; Mullins, J.

    Cladosporium conidia have been shown to be important aeroallergens in many regions throughout the world, but annual spore concentrations vary considerably between years. Understanding these annual fluctuations may be of value in the clinical management of allergies. This study investigates the number of days in summer when spore concentration exceeds the allergenic threshold in relation to regional temperature and precipitation at two sites in England and Wales over 27 years. Results indicate that number of days in summer when the Cladosporium spores are above the allergenic concentration is positively correlated with regional temperature and negatively correlated with precipitation for both sites over the study period. Further analysis used a winter North Atlantic Oscillation index to explore the potential for long-range forecasting of the aeroallergen. For both spore measurement sites, a positive correlation exists between the winter North Atlantic Oscillation index and the number of days in summer above the allergenic threshold for Cladosporium spore concentration.

  1. Variations in mugwort (Artemisia spp.) airborne pollen concentrations at three sites in central Croatia, in period from 2002 to 2003.

    PubMed

    Peternel, Renata; Hrga, Ivana; Culig, Josip

    2006-12-01

    In spite of the low atmospheric pollen levels, Artemisia sensitisation and allergy has been reported widely. The aim of the study was to determine the length of pollen season, intradiurnal, daily and monthly pollen variation, and the effect of some meteorological parameters on atmospheric pollen concentrations in Central Croatia. Seven-day Hirst volumetric pollen and spore traps were used for pollen sampling. The Artemisia pollen season lasted from the end of July until the end of September with the highest concentrations in August. The percentage of the total pollen count ranged from 0.52% to 0.92%. The intradiurnal peak occurred between 10 a.m. and 12 a.m. Statistical analysis showed a significant correlations between higher air temperature and high pollen concentration as well as high precipitation and low pollen concentration. Results of this study are expected to help in preventing the symptoms of allergic reaction in individuals with Artemisia pollen hypersensitivity. PMID:17243566

  2. Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos

    PubMed Central

    Beck, E. G.; Holt, P. F.; Manojlović, N.

    1972-01-01

    Beck, E. G., Holt, P. F., and Manojlović, N. (1972).Brit. J. industr. Med.,29, 280-286. Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos. The effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos are compared. Glass fibre behaves like chrysotile in producing an increase in cell membrane permeability in cultured macrophages. This is demonstrable by the increase in lactic dehydrogenase activity in the supernatant fluid. The metabolism, measured by lactate production, is not reduced as it is when quartz is phagocytosed. Glass powder behaves like the inert dust corundum, producing little change in the number of cells stained by erythrosin B and a small increase in lactate dehydrogenase activity, both being in the range of the control. There is an increase in lactate production as a result of higher metabolism due to phagocytosis. Dusts may produce two basic effects, namely a toxic effect and change in cell membrane permeability. A non-specific effect on the cell membrane due to the slow and sometimes incomplete process of ingestion of long fibres is probably a function of the morphology, particularly the length of the fibres. A primary specific effect induced by some dusts immediately follows contact with the cell membrane. Images PMID:4339803

  3. The effects of meteorological factors on airborne fungal spore concentration in two areas differing in urbanisation level

    NASA Astrophysics Data System (ADS)

    Oliveira, M.; Ribeiro, H.; Delgado, J. L.; Abreu, I.

    2009-01-01

    Although fungal spores are an ever-present component of the atmosphere throughout the year, their concentration oscillates widely. This work aims to establish correlations between fungal spore concentrations in Porto and Amares and meteorological data. The seasonal distribution of fungal spores was studied continuously (2005-2007) using volumetric spore traps. To determine the effect of meteorological factors (temperature, relative humidity and rainfall) on spore concentration, the Spearman rank correlation test was used. In both locations, the most abundant fungal spores were Cladosporium, Agaricus, Agrocybe, Alternaria and Aspergillus/Penicillium, the highest concentrations being found during summer and autumn. In the present study, with the exception of Coprinus and Pleospora, spore concentrations were higher in the rural area than in the urban location. Among the selected spore types, spring-autumn spores ( Coprinus, Didymella, Leptosphaeria and Pleospora) exhibited negative correlations with temperature and positive correlations both with relative humidity and rainfall level. On the contrary, late spring-early summer (Smuts) and summer spores ( Alternaria, Cladosporium, Epicoccum, Ganoderma, Stemphylium and Ustilago) exhibited positive correlations with temperature and negative correlations both with relative humidity and rainfall level. Rust, a frequent spore type during summer, had a positive correlation with temperature. Aspergillus/Penicillium, showed no correlation with the meteorological factors analysed. This knowledge can be useful for agriculture, allowing more efficient and reliable application of pesticides, and for human health, by improving the diagnosis and treatment of respiratory allergic disease.

  4. Vinyl flooring in the home is associated with children’s airborne butylbenzyl phthalate and urinary metabolite concentrations

    PubMed Central

    Just, Allan C.; Miller, Rachel L.; Perzanowski, Matthew S.; Rundle, Andrew G.; Chen, Qixuan; Jung, Kyung Hwa; Hoepner, Lori; Camann, David E.; Calafat, Antonia M.; Perera, Frederica P.; Whyatt, Robin M.

    2015-01-01

    Prior studies have shown that vinyl flooring, as well as the vinyl-softening plasticizers butylbenzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP), are associated with asthma and airway inflammation. While DEHP exposure is primarily dietary, whether home vinyl flooring contributes to indoor air and urinary metabolite concentrations for these two phthalates is unclear. Exposures to BBzP and DEHP were examined in a prospective birth cohort of New York City children (n=239) using: (1) visual observation of potential phthalate containing flooring, (2) a two-week home indoor air sample, and (3) concurrent urinary metabolites in a subset (n=193). The category “vinyl or linoleum” flooring was observed in 135 (56%) of monitored rooms; these rooms had statistically significantly higher indoor air geometric mean concentrations of BBzP (23.9 ng/m3) than rooms with wood or carpet flooring (10.6 ng/m3). Children from homes with “vinyl or linoleum” flooring also had significantly higher urinary BBzP metabolite concentrations than other children. Indoor air BBzP and urinary metabolite concentrations were correlated positively (Spearman’s rho 0.40). By contrast, indoor air DEHP was not associated with flooring type nor with its urinary metabolite concentrations. Vinyl flooring in the home may be an important source of children’s exposure to BBzP via indoor air. PMID:25690585

  5. Airborne pollutant characteristics in an urban, industrial and agricultural complex metroplex with high emission loading and ammonia concentration.

    PubMed

    Tsai, Jiun-Horng; Chang, Li-Peng; Chiang, Hung-Lung

    2014-10-01

    The size distribution of particulate mass and water-soluble ionic constituents and their gaseous precursors was investigated in a subtropical area, southern Taiwan. Field sampling and chemical analysis of particulate matter (PM) were conducted using a Micro Orifice Uniform Deposition Impactor (MOUDI) and a Nano-MOUDI, and gaseous pollutants were determined by a denuder-filter pack system. PM size mass distribution, mass concentration and ionic species concentration were measured during the day and at night in the winter and summer. Average PM concentrations in the winter were as high as 132 ± 42 μg/m(3), and PM mass concentrations in the summer were as low as 38 ± 19 μg/m(3). Generally, PM concentration was 111 ± 60 μg/m(3) at night, which was 20% higher than that in the daytime. The size-segregated mass distribution of PM mass concentration was over 85% in the 0.1-3.2 μm range. Ammonium, nitrate, and sulfate were the dominant water-soluble ionic species in PM, contributing 34%-48% of PM mass. High ammonia (12.9-49 μg/m(3)) and SO2 (2.6-27 μg/m(3)) were observed in the gas precursors. The molar ratio [Formula: see text] was 3.18 ± 1.20 at PM1.0, which indicated that the PM was rich in ammonium. Therefore, the excess ammonium could neutralize nitrate to form ammonium nitrate, after the more stable ammonium sulfate and ammonium bisulfate formation. PMID:25037046

  6. Measurement of airborne concentrations of tire and road wear particles in urban and rural areas of France, Japan, and the United States

    NASA Astrophysics Data System (ADS)

    Panko, Julie M.; Chu, Jennifer; Kreider, Marisa L.; Unice, Ken M.

    2013-06-01

    In addition to industrial facilities, fuel combustion, forest fires and dust erosion, exhaust and non-exhaust vehicle emissions are an important source of ambient air respirable particulate matter (PM10). Non-exhaust vehicle emissions are formed from wear particles of vehicle components such as brakes, clutches, chassis and tires. Although the non-exhaust particles are relatively minor contributors to the overall ambient air particulate load, reliable exposure estimates are few. In this study, a global sampling program was conducted to quantify tire and road wear particles (TRWP) in the ambient air in order to understand potential human exposures and the overall contribution of these particles to the PM10. The sampling was conducted in Europe, the United States and Japan and the sampling locations were selected to represent a variety of settings including both rural and urban core; and within each residential, commercial and recreational receptors. The air samples were analyzed using validated chemical markers for rubber polymer based on a pyrolysis technique. Results indicated that TRWP concentrations in the PM10 fraction were low with averages ranging from 0.05 to 0.70 μg m-3, representing an average PM10 contribution of 0.84%. The TRWP concentration in air was associated with traffic load and population density, but the trend was not statistically significant. Further, significant differences across days were not observed. This study provides a robust dataset to understand potential human exposures to airborne TRWP.

  7. Concentrations and size distributions of airborne influenza A viruses measured indoors at a health centre, a day-care centre and on aeroplanes.

    PubMed

    Yang, Wan; Elankumaran, Subbiah; Marr, Linsey C

    2011-08-01

    The relative importance of the aerosol transmission route for influenza remains contentious. To determine the potential for influenza to spread via the aerosol route, we measured the size distribution of airborne influenza A viruses. We collected size-segregated aerosol samples during the 2009-2010 flu season in a health centre, a day-care facility and onboard aeroplanes. Filter extracts were analysed using quantitative reverse transcriptase polymerase chain reaction. Half of the 16 samples were positive, and their total virus concentrations ranged from 5800 to 37,000 genome copies m(-3). On average, 64 per cent of the viral genome copies were associated with fine particles smaller than 2.5 µm, which can remain suspended for hours. Modelling of virus concentrations indoors suggested a source strength of 1.6±1.2×10(5) genome copies m(-3) air h(-1) and a deposition flux onto surfaces of 13±7 genome copies m(-2) h(-1) by Brownian motion. Over 1 hour, the inhalation dose was estimated to be 30±18 median tissue culture infectious dose (TCID50), adequate to induce infection. These results provide quantitative support for the idea that the aerosol route could be an important mode of influenza transmission. PMID:21300628

  8. Implementation of a near-real time cross-border web-mapping platform on airborne particulate matter (PM) concentration with open-source software

    NASA Astrophysics Data System (ADS)

    Knörchen, Achim; Ketzler, Gunnar; Schneider, Christoph

    2015-01-01

    Although Europe has been growing together for the past decades, cross-border information platforms on environmental issues are still scarce. With regard to the establishment of a web-mapping tool on airborne particulate matter (PM) concentration for the Euregio Meuse-Rhine located in the border region of Belgium, Germany and the Netherlands, this article describes the research on methodical and technical backgrounds implementing such a platform. An open-source solution was selected for presenting the data in a Web GIS (OpenLayers/GeoExt; both JavaScript-based), applying other free tools for data handling (Python), data management (PostgreSQL), geo-statistical modelling (Octave), geoprocessing (GRASS GIS/GDAL) and web mapping (MapServer). The multilingual, made-to-order online platform provides access to near-real time data on PM concentration as well as additional background information. In an open data section, commented configuration files for the Web GIS client are being made available for download. Furthermore, all geodata generated by the project is being published under public domain and can be retrieved in various formats or integrated into Desktop GIS as Web Map Services (WMS).

  9. Characteristics of mass concentrations depending on synoptic features during airborne dustfall episodes observed at Cheongwon in Korea in 2005

    NASA Astrophysics Data System (ADS)

    Kim, Hak-Sung; Chung, Yong-Seung

    2010-05-01

    Sandstorms in the desert and loess regions of north China and Mongolia, as well as the associated dustfall episodes on the Korean Peninsula, were monitored in 2005. The ground mass concentrations of PM10 and PM2.5 were analyzed during dustfall episodes at Cheongwon, in central south Korea, based on synoptic features at surface, 850 hPa and 500 hPa levels. A total of seven dustfall episodes lasting eleven days were observed and the mass concentration ratios of PM2.5 and PM10 during dustfall episodes were classified into a severe dustfall episode (SDE) and a moderate dustfall episode (MDE) depending upon two synoptic features. The main synoptic feature was for SDEs, which occurred frequently under a surface anticyclone and cyclone located in the west and east of the Korean Peninsula with large amplitude trough at 500 hPa over the northern Korean Peninsula. The sandstorms at the source headed directly to Korea via a strong N-NW wind without passing through any large cities or industrial areas of east China. The PM10 mass concentration sharply increased during the SDEs; however, the fine aerosol fraction of PM2.5 levels was relatively low with 13.6% of the mass concentration. In a synoptic feature for MDEs, a slow moving cyclone headed to Korea via the industrial areas of northeastern China under a small amplitude trough at a 500 hPa level. A weak anticyclone was also located over China. MDEs showed low mass concentrations of coarse PM10 particles and large fraction of fine PM2.5 particles at 46.3%.

  10. Airborne concentrations of PM(2.5) and diesel exhaust particles on Harlem sidewalks: a community-based pilot study.

    PubMed Central

    Kinney, P L; Aggarwal, M; Northridge, M E; Janssen, N A; Shepard, P

    2000-01-01

    Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10706526

  11. Diurnal variations of airborne pollen concentration and the effect of ambient temperature in three sites of Mexico City.

    PubMed

    Ríos, B; Torres-Jardón, R; Ramírez-Arriaga, E; Martínez-Bernal, A; Rosas, I

    2016-05-01

    Pollen is an important cause of allergic respiratory ailments in the Mexico City Metropolitan Area (MCMA). However, very little is known if ambient air temperature correlates with the early blooming of plants observed in other urban areas around the world. A research study was conducted during the dry season of 2012-2013 at three representative sites of the MCMA with different urban characteristics with the aim to understand the relationships between the profusion and diversity of pollen against temperature and other meteorological variables and degree of urbanization. Pollen samples were collected using a Hirst-type trap sampler in the sites: Merced (highly urbanized), Iztapalapa (medium-high urbanized) and Coyoacan (moderately urbanized). Urbanization levels were determined using a composite index based on population density, proportion of surface covered by construction and asphalt, and urban heat island intensity. A set of representative pollen sampling tapes were assayed under a light microscope at magnification of ×1,000 and converted to grains per cubic meter. The most representative pollen types found in the three sites were, regardless of urbanization levels were: Fraxinus, Cupressaceae/Taxodiaceae, Casuarina, Alnus, Myrtaceae, and Pinus. Total pollen concentration was greatest in the moderately urbanized area, although earlier blooming took place at the highly urbanized zone. Total pollen concentration in the medium-high urbanized site has the lowest because the green areas in this zone of MCMA are few. In a diurnal basis, the most abundant pollen types peaked near midday or in the afternoon evening at the three sites. A Spearman test showed a positive correlation among bihourly pollen concentrations, temperature and relative humidity in all sites, but wind speed just correlated in Iztapalapa and Coyoacan. The results obtained suggest that Urban Heat Island Intensity can disturb flowering periods and pollen concentrations, largely in the highly urbanized

  12. Diurnal variations of airborne pollen concentration and the effect of ambient temperature in three sites of Mexico City

    NASA Astrophysics Data System (ADS)

    Ríos, B.; Torres-Jardón, R.; Ramírez-Arriaga, E.; Martínez-Bernal, A.; Rosas, I.

    2016-05-01

    Pollen is an important cause of allergic respiratory ailments in the Mexico City Metropolitan Area (MCMA). However, very little is known if ambient air temperature correlates with the early blooming of plants observed in other urban areas around the world. A research study was conducted during the dry season of 2012-2013 at three representative sites of the MCMA with different urban characteristics with the aim to understand the relationships between the profusion and diversity of pollen against temperature and other meteorological variables and degree of urbanization. Pollen samples were collected using a Hirst-type trap sampler in the sites: Merced (highly urbanized), Iztapalapa (medium-high urbanized) and Coyoacan (moderately urbanized). Urbanization levels were determined using a composite index based on population density, proportion of surface covered by construction and asphalt, and urban heat island intensity. A set of representative pollen sampling tapes were assayed under a light microscope at magnification of ×1,000 and converted to grains per cubic meter. The most representative pollen types found in the three sites were, regardless of urbanization levels were: Fraxinus, Cupressaceae/Taxodiaceae, Casuarina, Alnus, Myrtaceae, and Pinus. Total pollen concentration was greatest in the moderately urbanized area, although earlier blooming took place at the highly urbanized zone. Total pollen concentration in the medium-high urbanized site has the lowest because the green areas in this zone of MCMA are few. In a diurnal basis, the most abundant pollen types peaked near midday or in the afternoon evening at the three sites. A Spearman test showed a positive correlation among bihourly pollen concentrations, temperature and relative humidity in all sites, but wind speed just correlated in Iztapalapa and Coyoacan. The results obtained suggest that Urban Heat Island Intensity can disturb flowering periods and pollen concentrations, largely in the highly urbanized

  13. Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

    NASA Technical Reports Server (NTRS)

    Abshire, James B.; Ramanathan, Anand; Riris, Haris; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Weaver, Clark J.; Browell, Edward V.

    2013-01-01

    We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5-6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s) matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2-3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were <1.4 ppm for flight measurement altitudes >6 km.

  14. Airborne observed and receptor-oriented modelled urban increments of anthropogenic CO2, CO and NOX concentrations in the megacity of London in summer 2012

    NASA Astrophysics Data System (ADS)

    Font Font, Anna Maria; Morguí, Josep Anton; Lee, James; McQuaid, Jim B.; Barratt, Benjamin

    2014-05-01

    A better characterization of the emissions and the dynamics of anthropogenic CO2 in large-urban centres are needed to implement more effective mitigation measures to combat climate change. This study aims to establish a representative emissions ratio of anthropogenic CO2 (CO2ff) in the megacity of London using CO and NOX as tracers. Observations of CO2, CO and NOX mixing ratios obtained onboard the NERC-ARSF aircraft undertaken on 12 July 2012 over the city of London were used. Airborne observations were taken at ~380 m along four transects crossing London, two in the morning (10:30 to 12:30 GMT) and two in the afternoon (15:30-16:30 GMT). The ratio of the amounts of CO and CO2 in excess of natural abundances (denoted as ΔCO and ΔCO2, respectively) from the airborne observations was used to determine the fraction of CO2 derived from burning fossil fuels (CO2ff). Total observations of CO and CO2 were compared to NOX observations and background concentrations were determined as the intercept when NOX mixing ratios equalled zero derived from standardised major axis linear regression. Excess concentrations were calculated by subtracting total amounts minus the background. ΔCO showed good correlation with ΔCO2 in the morning transects (R=0.95) but not in the afternoon (R=-0.50). The mean (±1σ) CO/CO2ff was derived from linear regression using the morning measurements and valued 5.0±0.4 ppb ppm-1. Lagrangian Particle Dispersion (LPD) simulations in backward mode were undertaken to model urban increments of anthropogenic CO2 and CO and to calculate the emissions ratio from the emissions inventory EDGAR v4.2. The LPD model FLEXPART was run with the meteorological data from the European Centre for Medium-Range Weather Forecasts (spatial resolution of 0.2 x 0.2 degrees; 91 vertical levels) and multiplied with the EDGAR emissions inventory (spatial resolution 0.1 x 0.1 degrees) to obtain an increment at each receptor point along the transects. Annual and temporal

  15. HOW ARE THE PHYSICAL AND CHEMICAL PROPERTIES OF CHRYSOTILE ASBESTOS ALTERED BY A 10-YEAR RESIDENCE IN WATER AND UP TO 5 DAYS IN SIMULATED STOMACH ACID

    EPA Science Inventory

    While there are many studies concerning the ingestion of chrysotile asbestos, there are a few studies concerning how the chrysotile asbestos itself is altered by the exposure to the acid stomach environment. It is shown that the charge on the surface, the Zeta potential, is chang...

  16. Parameterization of gaseous constituencies concentration profiles in the planetary boundary layer as required in support of airborne and satellite borne sensors

    NASA Technical Reports Server (NTRS)

    Kindle, E. C.; Condon, E.; Casas, J.

    1976-01-01

    The research to develop the capabilities for sensing air pollution constituencies using satellite or airborne remote sensors is reported. Sensor evaluation and calibration are analyzed including data reduction. The proposed follow-on research is presented.

  17. Amphibole, but not chrysotile, asbestos induces anti-nuclear autoantibodies and IL-17 in C57BL/6 mice

    PubMed Central

    Ferro, Aaron; Zebedeo, Christian Nash; Davis, Chad; Ng, Kok Whei; Pfau, Jean C.

    2016-01-01

    Exposure to amphibole asbestos has been associated with production of autoantibodies in mice and humans, and increases the risk of systemic autoimmune disease. However, epidemiological studies of chrysotile exposure have not indicated a similar induction of autoimmune responses. To demonstrate this difference in controlled exposures in mice, and to explore possible mechanistic explanations for the difference, C57BL/6 mice were exposed intratracheally to amphibole or chrysotile asbestos, or to saline only. Serum antinuclear antibodies (ANA), antibodies to extractable nuclear antigens (ENA), serum cytokines, and immunoglobulin isotypes were evaluated 8 months after the final treatment. The percentages of lymphocyte sub-sets were determined in the spleen and lungs. The results show that amphibole, but not chrysotile, asbestos increases the frequency of ANA/ENA in mice. Amphibole and chrysotile both increased multiple serum cytokines, but only amphibole increased IL-17. Both fibers decreased IgG1, without significant changes in other immunoglobulin isotypes. Although there were no gross changes in overall percentages of T- and B-cells in the spleen or lung, there was a significant increase in the normally rare populations of suppressor B-cells (CD19+, CD5+, CD1d+) in both the spleen and lungs of chrysotile-exposed mice. Overall, the results suggest that, while there may be an inflammatory response to both forms of asbestos, there is an autoimmune response in only the amphibole-exposed, but not the chrysotile-exposed mice. These data have critical implications in terms of screening and health outcomes of asbestos-exposed populations. PMID:24164284

  18. Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: Interim results

    SciTech Connect

    Bernstein, David M.; Rogers, Rick; Sepulveda, Rosalina; Kunzendorf, Peter; Bellmann, Bernd; Ernst, Heinrich; Phillips, James I.

    2014-04-01

    Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (> 20 μm) cleared quickly with T{sub 1/2} estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T{sub 1/2} > 1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. - Highlights: • We evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology observed at any time point in the brake-dust groups. • Crocidolite produced pathological response - Wagner 4 interstitial fibrosis by 32d.

  19. Use Of Superacids To Digest Chrysotile And Amosite Asbestos In Simple Mixtures Or Matrices Found In Building Materials Compositions

    DOEpatents

    Sugama, Toshifumi; Petrakis, Leon; Webster, Ronald P.

    1999-12-21

    A composition for converting asbestos-containing material to environmentally benign components is provided. The composition comprises a flouro acid decomposing agent which can be applied to either amosite-containing thermal insulation or chrysotile-containing fire-proof material or to any asbestos-containing material which includes of chrysotile and amosite asbestos. The fluoro acid decomposing agent includes FP(O)(OH).sub.2, hexafluorophosphoric acid, a mixture of hydrofluoric and phosphoric acid and a mixture of hexafluorophosphoric acid and phosphoric acid. A method for converting asbestos-containing material to environmentally benign components is also provided

  20. Use of super acids to digest chrysotile and amosite asbestos in simple mixtures or matrices found in building materials compositions

    SciTech Connect

    Sugama, T.; Petrakis, L.; Webster, R.P.

    1999-12-21

    A composition for converting asbestos-containing material to environmentally benign components is provided. The composition comprises a fluoro acid decomposing agent which can be applied to either amosite-containing thermal insulation or chrysotile-containing fire-proof material or to any asbestos-containing material which includes of chrysotile and amosite asbestos. The fluoro acid decomposing agent includes FP{sub 0}(OH){sub 2}, hexafluorophosphoric acid, a mixture of hydrofluoric and phosphoric acid and a mixture of hexafluorophosphoric acid and phosphoric acid. A method for converting asbestos-containing material to environmentally benign components is also provided.

  1. 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.

  2. Airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-06-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  3. Real-time detection of airborne asbestos by light scattering from magnetically re-aligned fibers.

    PubMed

    Stopford, Christopher; Kaye, Paul H; Greenaway, Richard S; Hirst, Edwin; Ulanowski, Zbigniew; Stanley, Warren R

    2013-05-01

    Inadvertent inhalation of asbestos fibers and the subsequent development of incurable cancers is a leading cause of work-related deaths worldwide. Currently, there is no real-time in situ method for detecting airborne asbestos. We describe an optical method that seeks to address this deficiency. It is based on the use of laser light scattering patterns to determine the change in angular alignment of individual airborne fibers under the influence of an applied magnetic field. Detection sensitivity estimates are given for both crocidolite (blue) and chrysotile (white) asbestos. The method has been developed with the aim of providing a low-cost warning device to trades people and others at risk from inadvertent exposure to airborne asbestos. PMID:23669992

  4. [Impact of modification of the fiber surface of chrysotile on its biological activity].

    PubMed

    Pylev, L N; Smirnova, O V; Vasil'eva, L A; Vezentsev, A I; Gudkova, E A; Naumova, L N; Neĭman, S M

    2007-01-01

    Samples of commercial chrysotile-asbestos and asbestos cement, which were equal in number, were prepared. The content of fibers, up to 80 microm in length, was 87.4 and 85.0% in the first and second samples, respectively. Chemical analysis confirmed that there were cement components onto the surface of fibrils in the second sample. Onto the surface of native asbestos fibers, there were considerable distribution bands of active centers in the range of pH values of 5, 6.4, and 7.3; their largest number was at pH 6.4. Asbestos cement fibers had a band at pH 7.3, i.e. there was displacement towards the neutral region. Thus, their capacity for oxidative processes is likely to be lower than that in the fibers from the first sample. The mutagenic activity of the commercial chrysotile, examined in the micronucleus test, was substantially higher (p < 0.01) than that in the asbestos cement sample wherein it did not differ from that seen in the control experiment (saline solution). Mutagenicity was not found in cement and asbestos cement dust (2-3% of fibers) either. It is probable that the absence of mutagenicity in the cement-coated asbestos fibers may be attributable to a considerable reduction in their potencies for the formation of active radicals (oxygen, lipid peroxidation, and others). PMID:17526242

  5. Effectiveness of serum megakaryocyte potentiating factor in evaluating the effects of chrysotile and its heated products on respiratory organs

    SciTech Connect

    Takata, Ayako; Yamauchi, Hiroshi; Toya, Tadao; Miyamoto-Kohno, Sayako; Iwatatsu, Yuka; Teranaka, Iroha; Aminaka, Masahito; Yamashita, Kiyotsugu; Kohyama, Norihiko

    2011-04-15

    Chrysotile (CH), the most common form of asbestos, is rendered less toxic by heating it at 1000 {sup o}C and converting it to forsterite (FO-1000). However, further safety tests are needed to evaluate human health risk of these materials. It has been reported that serum concentrations of megakaryocyte potentiating factor N-ERC/mesothelin become elevated in patients with mesotheliomas caused by asbestos exposure. In this study, a single 2 mg dose of CH or FO-1000 was intratracheally administered to rats. Within 180 days after the administrations, serum N-ERC/mesothelin concentrations, levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in lung tissues and pathological changes in respiratory organs were determined. In the CH group, a significant increase in serum N-ERC/mesothelin concentrations was observed immediately after intratracheal administration, and the elevation lasted for 30 days. In lung tissues, positive staining for 8-OHdG in bronchioles, alveolar epithelium, inflammatory cells, and granulomas was evidence of a marked DNA oxidative damage. Furthermore, measurements of 8-OHdG in lung tissues based on the HPLC-ECD method suggested that serum N-ERC/mesothelin concentrations tended to increase when there are significant DNA damages in lung tissues. In contrast, in the FO-1000 group, a marked rise in serum N-ERC/mesothelin concentrations occurred only in the early phase (1-7 days) after intratracheal administration. Similarly, FO-1000 induced elevation of 8-OHdG in lung tissues was transient and modest compared with those of the CH-treated animals. In both the CH and FO-1000 groups, we observed significant correlations between serum N-ERC/mesothelin concentrations and lung 8-OHdG concentrations (r = 0.559, p = 0.001 for the CH group; r = 0.516, p = 0.01 for the FO-1000 group). In summary, we demonstrated the possibility of using serum N-ERC/mesothelin concentrations as a useful biomarker for early phase exposure to either CH or FO-1000.

  6. Effects of Chrysotile Exposure in Human Bronchial Epithelial Cells: Insights into the Pathogenic Mechanisms of Asbestos-Related Diseases

    PubMed Central

    Gulino, Giulia Rossana; Polimeni, Manuela; Prato, Mauro; Gazzano, Elena; Kopecka, Joanna; Colombatto, Sebastiano; Ghigo, Dario; Aldieri, Elisabetta

    2015-01-01

    Background: Chrysotile asbestos accounts for > 90% of the asbestos used worldwide, and exposure is associated with asbestosis (asbestos-related fibrosis) and other malignancies; however, the molecular mechanisms involved are not fully understood. A common pathogenic mechanism for these malignancies is represented by epithelial–mesenchymal transition (EMT), through which epithelial cells undergo a morphological transformation to assume a mesenchymal phenotype. In the present work, we propose that chrysotile asbestos induces EMT through a mechanism involving a signaling pathway mediated by tranforming growth factor beta (TGF-β). Objectives: We investigated the role of chrysotile asbestos in inducing EMT in order to elucidate the molecular mechanisms involved in this event. Methods: Human bronchial epithelial cells (BEAS-2B) were incubated with 1 μg/cm2 chrysotile asbestos for ≤ 72 hr, and several markers of EMT were investigated. Experiments with specific inhibitors for TGF-β, glycogen synthase kinase–3β (GSK-3β), and Akt were performed to confirm their involvement in asbestos-induced EMT. Real-time polymerase chain reaction (PCR), Western blotting, and gelatin zymography were performed to detect mRNA and protein level changes for these markers. Results: Chrysotile asbestos activated a TGF-β–mediated signaling pathway, implicating the contributions of Akt, GSK-3β, and SNAIL-1. The activation of this pathway in BEAS-2B cells was associated with a decrease in epithelial markers (E-cadherin and β-catenin) and an increase in mesenchymal markers (α-smooth muscle actin, vimentin, metalloproteinases, and fibronectin). Conclusions: Our findings suggest that chrysotile asbestos induces EMT, a common event in asbestos-related diseases, at least in part by eliciting the TGF-β–mediated Akt/GSK-3β/SNAIL-1 pathway. Citation: Gulino GR, Polimeni M, Prato M, Gazzano E, Kopecka J, Colombatto S, Ghigo D, Aldieri E. 2016. Effects of chrysotile exposure in human

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

    PubMed

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

    2011-07-01

    Iran imports nearly 55,000 metric tons of asbestos per year, and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, asbestos fiber concentrations during AC sheet and pipe manufacturing were measured by phase-contrast microscopy (PCM) and polarized light microscopy (PLM) in 98 personal air samples. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Personal monitoring of fiber levels indicated a range from 0.02 to 0.55PCM f/ml (0.02-0.69PLM f/ml). The AC workers' geometric mean asbestos exposure was 0.09 PCM f/ml (0.11 PLM f/ml), with arithmetic mean of 0.13 PCM f/ml (0.16 PLM f/ml). The observed fiber concentrations in many processes were higher than the threshold limit value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), which is 0.1 f/ml. Based on these findings, the PLM values were approximately 25% higher than PCM values. The SEM data demonstrate that fibrous particles contained chrysotile. The thinnest fiber recognized by SEM had a diameter of 0.2μm. Mean exposure exceeded the TLV for asbestos in pipe molding and finishing (100%) as well as sheet molding and finishing (45.5-83.3%). In conclusion exposure control may be needed to be in compliance with the ACGIH TLV and other guidance levels. Also, with regard to PCM limitations for airborne fiber analysis, the use of microscopic methods other than PCM can be used to improve the techniques used presently. PMID:21420461

  8. An airborne isothermal haze chamber

    NASA Technical Reports Server (NTRS)

    Hindman, E. E.

    1981-01-01

    Thermal gradient diffusion cloud chambers (TGDCC) are used to determine the concentrations of cloud condensation nuclei (CCN) with critical supersaturations greater than or equal to about 0.2%. The CCN concentrations measured with the airborne IHC were lower than theoretically predicted by factors ranging between 7.9 and 9.0. The CCN concentrations measured with the airborne IHC were lower than the concentrations measured with the larger laboratory IHC's by factors ranging between 3.9 and 7.5. The bounds of the supersaturation ranges of the airborne IHC and the CSU-Mee TGDCC do not overlap. Nevertheless, the slopes of the interpolated data between the bounds agree favorably with the theoretical slopes.

  9. Growth of carbon structures on chrysotile surface for organic contaminants removal from wastewater.

    PubMed

    Lemos, Bruno R S; Soares, Érico A R; Teixeira, Ana Paula C; Ardisson, José D; Fernandez-Outon, Luis E; Amorim, Camila C; Lago, Rochel M; Moura, Flávia C C

    2016-09-01

    Amphiphilic magnetic composites were produced based on chrysotile mineral and carbon structures by chemical vapor deposition at different temperatures (600-900 °C) and cobalt as catalyst. The materials were characterized by elemental analysis, X-ray diffraction, vibrating sample magnetometry, adsorption and desorption of N2, Raman spectroscopy, scanning electronic microscopy, and thermal analysis showed an effective growth of carbon structures in all temperatures. It was observed that at 800 and 900 °C, a large amount of carbon structures are formed with fewer defects than at 600 and 700 °C, what contributes to their stability. In addition, the materials present magnetic phases that are important for their application as catalysts and adsorbents. The materials have shown to be very active to remove the oil dispersed in a real sample of emulsified wastewater from biodiesel production and to remove methylene blue by adsorption and oxidation via heterogeneous Fenton mechanism. PMID:27343867

  10. Space-and-time current spectroscopy of nanostructured selenium in the chrysotile asbestos matrix

    NASA Astrophysics Data System (ADS)

    Bryushinin, M. A.; Kulikov, V. V.; Kumzerov, Yu. A.; Mokrushina, E. V.; Petrov, A. A.; Sokolov, I. A.

    2014-08-01

    The non-steady-state photoelectromotive force effect was experimentally studied in a semiconductor nanowire array, i.e., in a composite representing selenium in a chrysotile asbestos matrix. The sample was exposed to an oscillating interference pattern, and the material response was measured as an alternating electric current. The experiments were performed for two geometries in which the excited photocurrent was parallel or perpendicular to nanowires. The dependences of the signal amplitude on the phase modulation frequency, spatial frequency, light polarization, and temperature were obtained. The photoelectric parameters of the material were determined for the light wavelength λ = 633 nm. The effect was theoretically analyzed for the semiconductor model with shallow traps, which allowed the explanation of the observed increase in the signal amplitude in the presence of additional phase modulation.

  11. Acoustic phonons in chrysotile asbestos probed by high-resolution inelastic x-ray scattering

    SciTech Connect

    Mamontov, Eugene; Vakhrushev, S. B.; Kumzerov, Yu. A,; Alatas, A.

    2009-01-01

    Acoustic phonons in an individual, oriented fiber of chrysotile asbestos (chemical formula Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}) were observed at room temperature in the inelastic x-ray measurement with a very high (meV) resolution. The x-ray scattering vector was aligned along [1 0 0] direction of the reciprocal lattice, nearly parallel to the long axis of the fiber. The latter coincides with [1 0 0] direction of the direct lattice and the axes of the nano-channels. The data were analyzed using a damped harmonic oscillator model. Analysis of the phonon dispersion in the first Brillouin zone yielded the longitudinal sound velocity of (9200 {+-} 600) m/s.

  12. An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy.

    PubMed Central

    Piolatto, G; Negri, E; La Vecchia, C; Pira, E; Decarli, A; Peto, J

    1990-01-01

    The mortality experience of a cohort of chrysotile miners employed since 1946 in Balangero, northern Italy was updated to the end of 1987 giving a total of 427 deaths out of 27,010 man-years at risk. A substantial excess mortality for all causes (standardised mortality ratio (SMR) = 149) was found, mainly because of high rates for some alcohol related deaths (hepatic cirrhosis, accidents). For mortality from cancer, however, the number of observed deaths (82) was close to that expected (76.2). The SMR was raised for oral cancer (SMR 231 based on six deaths), cancer of the larynx (SMR 267 based on eight deaths), and pleura (SMR 667 based on two deaths), although the excess only reached statistical significance for cancer of the larynx. Rates were not increased for lung, stomach, or any other type of cancer. No consistent association was seen with duration or cumulative dust exposure (fibre-years) for oral cancer, but the greatest risks for laryngeal and pleural cancer were in the highest category of duration and degree of exposure to fibres. Although part of the excess mortality from laryngeal cancer is probably attributable to high alcohol consumption in this group of workers, the data suggest that exposure to chrysotile asbestos (or to the fibre balangeroite that accounts for 0.2-0.5% of total mass in the mine) is associated with some, however moderate, excess risk of laryngeal cancer and pleural mesothelioma. The absence of excess mortality from lung cancer in this cohort is difficult to interpret. Images PMID:2176805

  13. X-ray Absorption Spectroscopy of Zinc in Airborne Particulate Matter Shows Tire Debris Concentrated in > 0.5 μm Fraction

    NASA Astrophysics Data System (ADS)

    Pingitore, N. E.; Clague, J. W.; Gill, T. E.; Amaya, M. A.; Cahill, T. A.

    2009-12-01

    Using X-ray absorption spectroscopy (XAS), we speciated Zn in size-resolved fractions of particulate matter (PM) from El Paso, Texas. Spectral patterns indicated that Zn in tire debris is the dominant form of Zn in PM coarser than 0.5 μm in aerodynamic diameter. Although concentrated in the > 0.5 μm fraction, a large portion of the tire debris in PM is small enough to penetrate and deposit in the lower respiratory tract. We collected 3 sets of size-resolved samples of airborne particulate matter (PM) over periods of several days to several weeks in November 2008, and April and May 2009. Local PM compositions typically are dominated by anthropogenic input in November and geologic sources in April, and a mixture in May. The collection site is in the urban core of El Paso, TX, contiguous to the University of Texas at El Paso, 0.6 km from Interstate Highway 10, 0.4 km from State Highway 20, and 1 km from Cd. Juarez, Chihuahua, Mexico. The DRUM sampler (Davis Rotating Uniform size-cut Monitor) employs a rotating Lundgren-type impactor, draws 10 l per minute, and deposits PM on plastic strips mounted on rotating drums. The sampler collected and segregated ambient PM into 8 size cuts: 12-5 μm, 5-2.5, 2.5-1.15, 1.15-0.75, 0.75-0.56, 0.56-0.34, 0.34-0.26, and 0.26-0.09. We conducted the X-ray absorption spectroscopy (XAS) experiments at the Stanford Synchrotron Radiation Lightsource on beam line 7-3. Spectra of the 24 samples of PM and numerous model compounds were collected at the Zn K absorption edge in fluorescence mode using a 30-element Ge solid-state detector. The overall spectral patterns from the 3 seasons were similar to one another. But strikingly, each set of 8 XAS spectra displayed an obvious change in the Zn speciation at the 0.56-0.75 μm size cut. We compared the PM spectra to those of our suite of known model compounds and materials. The spectral pattern of the coarser size cuts was quite similar to those of the tires we tested. The Zn in the tires

  14. Survival rate of airborne Mycobacterium bovis.

    PubMed

    Gannon, B W; Hayes, C M; Roe, J M

    2007-04-01

    Despite years of study the principle transmission route of bovine tuberculosis to cattle remains unresolved. The distribution of pathological lesions, which are concentrated in the respiratory system, and the very low dose of Mycobacterium bovis needed to initiate infection from a respiratory tract challenge suggest that the disease is spread by airborne transmission. Critical to the airborne transmission of a pathogenic microorganism is its ability to survive the stresses incurred whilst airborne. This study demonstrates that M. bovis is resistant to the stresses imposed immediately after becoming airborne, 94% surviving the first 10 min after aerosolisation. Once airborne the organism is robust, its viability decreasing with a half-life of approximately 1.5 hours. These findings support the hypothesis that airborne transmission is the principle route of infection for bovine tuberculosis. PMID:17045316

  15. Penetration of >5-. mu. m chrysotile fibers through DuPont Tyvek 1422A and Kimberly-Clark CPF fabrics

    SciTech Connect

    Weeks, R.W. Jr.; McLeod, M.J.

    1982-02-01

    Aerosols of 4.1-..mu..m mass median aerodynamic diameter chrysotile fibers were generated and passed through stitched (seamed) and unstitched (unseamed) DuPont Tyvek 1422A and Kimerly-Clark composite polypropylene fabric (CPF) spunbonded fabrics. The two unstitched fabrics and the two stitched fabrics were penetrated by amounts of chrysotile, which did not allow a statistically significant difference in penetration to be observed. Both Tyvek and the CPF allowed approximately a 1% penetration through the unstitched material and approximately a 30% penetration through the stitched material. These values refer to the suit materials per se and not to the entire garment. As such, they should not be considered as representative of the entire suit as worn by personnel.

  16. Penetration of >5-. mu. chrysotile asbestos fibers through DuPont Tyvek 1422A and Kimberly-Clark CPF fabrics

    SciTech Connect

    Weeks, R.W. Jr.; McLeod, M.J.

    1981-01-01

    Aerosols of 4.1-..mu.. mass median aerodynamic diameter chrysotile asbestos fibers were generated and passed through stitched (seamed) and unstitched (unseamed) DuPont Tyvek 1422A and Kimberly-Clark composite polypropylene fabric (CPF) spunbonded fabrics. The two unstitched fabrics and the two stitched fabrics were penetrated by amounts of chrysotile which did not allow a statistically significant difference in penetration to be observed. Both the Tyvek and the CPF allowed approximately a 1% penetration through the unstitched material and approximately a 30% penetration through the stitched material. These values refer to the suit materials per se and not to the entire garment. As such, they should not be considered as representative of the entire suit as worn by Navy personnel.

  17. An updated evaluation of reported no-observed adverse effect levels for chrysotile asbestos for lung cancer and mesothelioma.

    PubMed

    Pierce, Jennifer S; Ruestow, Peter S; Finley, Brent L

    2016-08-01

    Although consumption of chrysotile asbestos has decreased since the 1970s, the latency period of asbestos-related cancers is thought to be at least 20-30 years, and therefore the potential health risks associated with historical exposures is still actively researched. This analysis represents an update to a previous paper in which we evaluated the exposure-response relationships for lung cancer and mesothelioma in chrysotile-exposed cohorts. Here, we review several recently published studies as well as updated information from previous studies. For each of the 14 studies considered, we identified the "no-observed adverse effect level" (NOAEL) for lung cancer and/or mesothelioma. NOAEL values for lung cancer ranged from 1.1 to <20 f/cc-years to 1600-3200 f/cc-years, and for mesothelioma ranged from 100-400 f/cc-years to 800-1599 f/cc-years. The range of "best estimate" NOAELs was estimated to be 89-168 f/cc-years for lung cancer and 208-415 f/cc-years for mesothelioma. None of the six cohorts of cement or friction product manufacturing workers exhibited an increased lung cancer risk at any exposure level, while all of the five studies of textile workers reported an increased risk at one or more exposure levels. This is likely because friction and cement workers were exposed to much shorter chrysotile fibers. Of the seven cases of peritoneal mesothelioma reported in the included studies, none were observed in the analyses of cement or friction product manufacturing workers in the absence of crocidolite exposure. These findings will help characterize potential worker and consumer health risks associated with historical and current chrysotile exposures. PMID:27031024

  18. Change of carcinogenic chrysotile fibers in the asbestos cement (eternit) to harmless waste by artificial carbonatization: petrological and technological results.

    PubMed

    Radvanec, Martin; Tuček, L'ubomír; Derco, Ján; Čechovská, Katarína; Németh, Zoltán

    2013-05-15

    Asbestos cement materials, mainly the eternit roof ceiling, being widely applied in the past, represent a serious environmental load. The solar radiation, rain and frost cause the deliberation of cement from the eternit roofing and consequently the wind contaminates the surrounding area by the asbestos (chrysotile) fibers. In combination with other carcinogens (e.g. smoking), or at reduced immunity of a man, they may cause serious respiratory diseases and lung cancer. The article presents the procedure and experimental results of artificial carbonatization, applied in the asbestos cement (eternit). The wet crushed and pulverized asbestos cement was thermally modified at 650°C and then the chrysotile fibers easily and completely reacted with the mixture of CO2 and water, producing new Mg-rich carbonates - hydromagnesite and magnesite: [Formula: see text] Applying this methodology, the asbestos-bearing waste can be stabilized and environmentally friendly permanently deposited. Finding a way of neutralizing of extreme pH values (around 12) at large eternit dumps represents also an asset of presented research. Simultaneously, the artificial carbonatization of chrysotile asbestos, applying CO2, offers an alternative way for permanent liquidation of a part of industrial CO2 emissions, contributing to multiple benefit of this methodology. PMID:23571021

  19. Determination of Micro-Quantities of Chrysotile Asbestos by Dye Adsorption

    ERIC Educational Resources Information Center

    Markham, M. Clare; Wosczyna, Karen

    1976-01-01

    Airborne asbestos is analyzed by differential dye adsorption. Quantities can be estimated down to 100 mg. For industrial use, asbestos samples must be separated from interfering minerals by density flotation. (Author/BT)

  20. Chrysotile asbestos and health in Zimbabwe: II. Health status survey of active miners and millers

    SciTech Connect

    Cullen, M.R.; Lopez-Carrillo, L.; Alli, B.; Pace, P.E.; Shalat, S.L.; Baloyi, R.S. )

    1991-02-01

    As part of the effort to establish industrial practice and public policy regarding asbestos in Zimbabwe, we have conducted a cross-sectional study of the chrysotile mines and mills. A stratified random sample of workers with greater than 10 years of exposure has been evaluated by spirometry, chest radiographs, and employment history. The latter was converted to quantitative estimates of exposure dose, using a matrix based on measured and reconstructed fiber levels for each job and facility during the years of work. Based on these data, a clear dose-response between asbestos exposure and functional loss has been demonstrated, with mean losses from predicted of about 400-600 cc in vital capacity in the 10% of the population with heaviest exposures. Low-grade parenchymal radiographic abnormalities (ILO grade greater than or equal to 1/0) were evident in 8.7% of the total study group and were almost 10 times more common in those with more than 100 fibers/cc.years cumulative exposure than in those with 16 fibers/cc.years or less. Pleural disease was relatively rare, occurring in just under 10% of the study group, and was unrelated to exposure dose. Overall, these findings are compatible with results of similar studies in Quebec and Swaziland and suggest that similar control strategies are probably indicated.

  1. Late progression of radiographic changes in Canari chrysotile mine and mill exworkers.

    PubMed

    Viallat, J R; Boutin, C; Pietri, J F; Fondarai, J

    1983-01-01

    The present radiological status of 133 exworkers (mean age: 58 +/- 0.7 yr) of the chrysotile mine of Canari (Corsica) was compared to that recorded in 1965, when the mine was closed. The mean time since first exposure is 27 +/- 0.4 yr, and the mean time since termination of asbestos exposure equals 16 +/- 0.3 yr. This study showed an evolution of radiographic changes: in 1965 only 14% of the subjects had grade 1/1 or more parenchymal fibrosis, and 6% had bilateral pleural lesions; in 1979 these percentages reached 40% and 27%, respectively. Subjects who had a given parenchymal change in 1965 (e.g., 1/1 grade lesions) were older and had a more intensive dust exposure and tobacco consumption than exminers who developed the same parenchymal changes much later. A progression of parenchymal changes was observed in 39% of the subjects with normal findings in 1965, and in 63% of the subjects with grade 1/1 or more changes in 1965. Those who progressed (46% of the cohort) were older, had a longer exposure, and a more intensive dust exposure and cigarette smoking than nonprogressors. PMID:6299211

  2. Reduction of chrysotile asbestos-induced genotoxicity in human peripheral blood lymphocytes by garlic extract.

    PubMed

    Bhattacharya, Kunal; Yadava, Santosh; Papp, Thilo; Schiffmann, Dietmar; Rahman, Qamar

    2004-11-28

    Asbestos fibers are well known environmental carcinogen, however, the underlying mechanisms of their action have still not clearly been identified. Asbestos is capable of depleting glutathione and generating reactive oxygen species (ROS), which are important mediators of damage in biological system. Asbestos-induced mutagenecity, may be mediated by the generation. It is known that a number of scavengers and antioxidants attenuate asbestos-induced ROS release. Furthermore, it is known that garlic, contains numerous sulfur compounds and glutathione precursors which act as antioxidants and also demonstrate anticarcinogenic properties. The aim of this study was to investigate whether garlic extract has any influence on asbestos-mediated genotoxicity. As an assay system, we applied the micronucleus assay, sister chromatid exchanges, and chromosomal aberrations with human peripheral blood lymphocytes, which has already been used to analyze the genotoxicity of asbestos fibers. Our results indicate that garlic extract, when administered to the lymphocytes cell culture simultaneously with chrysotile reduced the rates of micronucleus formation, sister chromatid exchanges, and chromosomal aberrations significantly. We conclude that garlic extract may be an efficient, physiologically tolerable quencher of asbestos-mediated genotoxicity. PMID:15454308

  3. Effects of chrysotile asbestos on coho salmon and green sunfish: evidence of behavioral and pathological stress

    SciTech Connect

    Belanger, S.E.; Schurr, K.; Allen, D.J.; Gohara, A.F.

    1986-02-01

    The effects of chrysotile asbestos on larval coho salmon (Oncorhynchus kisutch) and juvenile green sunfish (Lepomis cyanellus) were investigated at levels approximating those reported in the Great Lakes basin (10(6) fibers/liter). Behavioral stress effects, such as loss of rheotaxic position and balance, were observed in salmon exposed at 3.0 X 10(6) fibers/liter and in sunfish exposed at 1.5 and 3.0 X 10(6) fibers/liter. Coho larvae at 1.5 X 10(6) fibers/liter were significantly more susceptible to an anesthetic stress test, becoming ataxic and losing equilibrium faster than control cohorts (P less than 0.001). Two of 106 larvae exposed at 3.0 X 10(6) fibers/liter developed tumorous swellings and three additional fish developed coelomic distentions. Cytological examination of ventral epidermal tissue revealed cellular histolysis, and evidence by transmission electron microscopy confirmed the presence of asbestos in the salmon larvae. Distortion of the lateral line region in asbestos-treated coho salmon was linked to behavioral and orientational aberrations. Differential mortality was not observed between control and treated groups of either test species.

  4. Diffusion of benzene confined in the oriented nanochannels of chrysotile asbestos fibers

    SciTech Connect

    Mamontov, E.; Kumzerov, Yu.A.; Vakhrushev, S.B.

    2005-11-01

    We used quasielastic neutron scattering to study the dynamics of benzene that completely fills the nanochannels of chrysotile asbestos fibers with a characteristic diameter of about 5 nm. The macroscopical alignment of the nanochannels in fibers provided an interesting opportunity to study anisotropy of the dynamics of confined benzene by means of collecting the data with the scattering vector either parallel or perpendicular to the fibers axes. The translational diffusive motion of benzene molecules was found to be isotropic. While bulk benzene freezes at 278.5 K, we observed the translational dynamics of the supercooled confined benzene on the time scale of hundreds of picoseconds even below 200 K, until at about 160 K its dynamics becomes too slow for the {mu}eV resolution of the neutron backscattering spectrometer. The residence time between jumps for the benzene molecules measured in the temperature range of 260 K to 320 K demonstrated low activation energy of 2.8 kJ/mol.

  5. [The problem of determining asbestos in bulk materials: a study of the effect of grinding on the diffractometric response of the chrysotile content in an asbestos cement sample].

    PubMed

    Puledda, S; Paoletti, L

    1993-01-01

    To determine the asbestos content in a bulk sample by X-ray diffractometry, the sample must be previously comminuted until an adequate granulometry is reached. However, this treatment can produce a decrease in fibre crystallinity which, in turn, causes an attenuation of the diffractometric response of asbestos. The authors studied a "wet" comminution method that was tested on an asbestos-cement sample containing chrysotile. This procedure made it possible to limit the attenuation of the diffractometric response of chrysotile to reasonable values (about 20%). Moreover, the study of the comminution kinetics revealed a time interval during which both fibre granulometry and diffractometric response tend to reach a plateau value. In this interval, the comminution time is not a critical factor with respect to the diffractometric behaviour of chrysotile. Therefore, this interval offers favourable conditions for preparing bulk samples to be submitted to X-ray diffraction. PMID:8255261

  6. Comparative cytotoxicity study of rock wool and chrysotile by cell magnetometric evaluation.

    PubMed

    Kudo, Yuichiro; Watanabe, Mitsuyasu; Okada, Mitsushi; Shinji, Hisako; Niitsuya, Masato; Satoh, Toshihiko; Sakai, Yasuhiro; Kohyama, Norihiko; Kotani, Makoto; Aizawa, Yoshiharu

    2003-11-01

    Rock wool (RW), a type of man-made mineral fiber (MMMF), is a building material used as an asbestos substitute for heat insulation, fire resistance, and reinforcement. RW is included in group 3 of the IARC classification. In the present study, the cytotoxicity of RW was investigated by cell magnetometry, enzyme assay, DNA ladder detection, and electron microscopic morphological evaluation in comparison with chrysotile fibers (CF). Specimens were prepared by 18-h incubation of Fischer rat alveolar macrophages in the presence of RW fibers as the study material, CF as positive control, and phosphate-buffered saline (PBS) as negative control, together with a relaxation indicator, Fe3O4, except for morphological evaluation, followed by additional procedures of external magnetization and subsequent 20-min remanent magnetic field measurement for magnetometric evaluation, and macrophage DNA extraction for evaluating possible apoptosis by DNA ladder detection. In magnetometry, relaxation, a marker of cytotoxicity, was rapid in both the RW- and PBS-treated groups, while it was delayed in both the long and short CF-treated groups. Differences in percent lactate dehydrogenase (LDH) release between the RW-treated group and PBS-treated group were not significant, but those between the RW-treated group and short CF-treated group were statistically significant. A DNA ladder was not detected in any of the study groups. Electron micrographs showed that RW did not cause any change, but CF caused changes in macrophages. Thus, magnetometric measurements suggested no cytotoxicity of RW. We plan, in the future, to evaluate the safety of RW by magnetometric measurement and morphological observation of the lungs in in vivo inhalation experiments. PMID:14569493

  7. Asbestos exposure, cigarette smoking, and airflow limitation in long-term Canadian chrysotile miners and millers

    SciTech Connect

    Begin, R.; Boileau, R.; Peloquin, S.

    1987-01-01

    To investigate further the relationships of asbestos exposure, cigarette smoking, and airflow limitation, we have obtained detailed pulmonary function tests (PFT) in 331 long-term Canadian chrysotile workers, 34 of whom were lifetime nonsmokers. Three disease categories were defined on the bases of standard diagnostic criteria, gallium-67 lung uptake, and the lung pressure-volume curve. Category A was composed of workers without changes suggestive of alveolitis or asbestosis. There were eight nonsmokers (ns), among whom we found a statistically significant 30% reduction in airflow conductance (Gus) at low lung volume, which is consistent with the concept of an asbestos airway lesion. The 85 smokers (sm) of category A had reduction of Gus at both high and low lung volumes. Category B was composed of workers without asbestosis but with evidence of asbestos alveolitis. In the six ns, Gus was significantly reduced to 50% normal at low lung volume. The 59 sm had reduction of Gus at both high and low lung volumes but less severely than sm in category A. Category C was composed of workers with asbestosis. The 20 ns had restrictive pattern of lung function, and Gus was decreased to 39% normal at 50% TLC. The 153 sm in C had airflow reduction comparable to sm in B. We concluded that asbestos exposure, which leads to asbestos airway disease, asbestos peribronchiolar alveolitis, and asbestosis, causes airflow limitation at low lung volume but does not reduce the expiratory flow rates on the flow-volume curve in lifetime nonsmokers. In the smoking asbestos workers with alveolitis or asbestosis, the major component of airflow limitation is a smoking effect. In these smoking workers, rigidity of the lung lessens airflow obstruction associated with smoking at the expense of increased work of breathing.

  8. Bronchoalveolar lavage fluid cellular profile in workers exposed to chrysotile asbestos.

    PubMed

    Kokkinis, Fevos P; Bouros, Demosthenes; Hadjistavrou, Konstantinos; Ulmeanu, Ruxandra; Serbescu, Anneta; Alexopoulos, Evangelos C

    2011-10-01

    The cellular profile of bronchoalveolar lavage fluid (BALF) in asbestos-exposed population remains controversial. We, therefore, aimed to investigate BALF in apparently healthy individuals that were exposed in asbestos-related work for a long period of time. Participants were selected among employees of a car brakes and clutches factory that used chrysotile asbestos. Selection criteria were an employment history of ≥ 15 years and the absence of severe respiratory disease. The total number and type of BALF cells, the existence of dust cells, iron-laden macrophages and asbestos bodies were assessed. Thirty-nine workers (25 men), with a mean age of 46.2 ± 4.2 years and a mean employment time of 23.5 ± 4 years, participated. Asbestos bodies were observed in 14 out of 39 (36%) specimens, dust cells in 37 and iron-laden macrophages in all. Those with asbestos bodies had at least 3 times higher probability to have lymphocytosis (lymphocytes > 11%: 64% vs 28%, p = 0.027) and had an increased percentage of iron-laden macrophages compared to those without asbestos bodies (median values: 42% vs 13%, p = 0.08). Smokers (36%) had less lymphocytes compared to non and ex-smokers (median values: 6% vs. 13%, p = 0.002), and iron-laden macrophages count had a positive relation (r = 0.31, p = 0.05) to lymphocyte count. Asbestos-exposed asymptomatic individuals with the presence of asbestos bodies in the BALF are more likely to have lymphocytic alveolitis while concurrent dust exposure and smoking habits hold a significant role. PMID:21421677

  9. Assessment of asbestos body formation by high resolution FEG-SEM after exposure of Sprague-Dawley rats to chrysotile, crocidolite, or erionite.

    PubMed

    Gandolfi, Nicola Bursi; Gualtieri, Alessandro F; Pollastri, Simone; Tibaldi, Eva; Belpoggi, Fiorella

    2016-04-01

    This work presents a comparative FEG-SEM study of the morphological and chemical characteristics of both asbestos bodies and fibres found in the tissues of Sprague-Dawley rats subjected to intraperitoneal or intrapleural injection of UICC chrysotile, UICC crocidolite and erionite from Jersey, Nevada (USA), with monitoring up to 3 years after exposure. Due to unequal dosing based on number of fibres per mass for chrysotile with respect to crocidolite and erionite, excessive fibre burden and fibre aggregation during injection that especially for chrysotile would likely not represent what humans would be exposed to, caution must be taken in extrapolating our results based on instillation in experimental animals to human inhalation. Notwithstanding, the results of this study may help to better understand the mechanism of formation of asbestos bodies. For chrysotile and crocidolite, asbestos bodies are systematically formed on long asbestos fibres. The number of coated fibres is only 3.3% in chrysotile inoculated tissues. In UICC crocidolite, Mg, Si, and Fe are associated with the fibres whereas Fe, P and Ca are associated with the coating. Even for crocidolite, most of the observed fibres are uncoated as coated fibres are about 5.7%. Asbestos bodies do not form on erionite fibres. The crystal habit, crystallinity and chemistry of all fibre species do not change with contact time, with the exception of chrysotile which shows signs of leaching of Mg. A model for the formation of asbestos bodies from mineral fibres is postulated. Because the three fibre species show limited signs of dissolution in the tissue, they cannot act as source of elements (primarily Fe, P and Ca) promoting nucleation and growth of asbestos bodies. Hence, the limited number of coated fibres should be due to the lack of nutrients or organic nature. PMID:26705886

  10. Comparison of predicted ground-level airborne radionuclide concentrations to measured values resulting from operation of the Los Alamos Meson Physics Facility. Master's thesis

    SciTech Connect

    Hoak, W.V.

    1993-05-01

    A comparison study of measured and predicted downwind radionuclide concentrations from the Los Alamos Meson Physics Facility (LAMPF) was performed. The radionuclide emissions consist primarily of the radioisotopes 11C, 13N, and 150. The gases, vented to the outside environment by a stack located at the facility, potentially increase the radiation exposure at the facility boundary. Emission rate, meteorological, and radiation monitoring station data were collected between September 26, 1992 and October 3, 1992. The meteorological and emission data were input to the Clean Air Act Assessment Package-1988 (CAP88-PC) computer code. The downwind radionuclide air concentrations predicted by the code were compared to the air concentrations measured by the monitoring stations. The code was found to slightly over-predict downwind concentrations during unstable atmospheric conditions. For stable atmospheric conditions, the code was not useful for predicting downwind air concentrations. This is thought to be due to an underestimation of horizontal dispersion.

  11. AIRBORNE MERCURY DEPOSITION AND WATERSHED CHARACTERISTICS IN RELATION TO MERCURY CONCENTRATIONS IN WATER, SEDIMENTS, PLANKTON, AND FISH OF EIGHTY NORTHERN MINNESOTA LAKES

    EPA Science Inventory

    In light of increasing fish consumption advisories in several states, a comprehensive multimedia database was created to answer a variety of questions. Mercury concentrations in precipitation, lake water and sediment, zooplankton, and fish were measured and analyzed together with...

  12. Improved Instrumentation for the Detection of Atmospheric CO2 Concentration using an Airborne IPDA LIDAR for 2014 NASA ASCENDS Science Campaign

    NASA Astrophysics Data System (ADS)

    Allan, G. R.; Riris, H.; Hasselbrack, W. E.; Rodriguez, M.; Ramanathan, A. K.; Sun, X.; Mao, J.; Abshire, J. B.

    2014-12-01

    NASA-GSFC is developing a twin-channel, Integrated-Path, Differential Absorption (IPDA) lidar to measure atmospheric CO2 from space as a candidate for NASA's ASCENDS mission (Active Sensing of CO2 Emissions over Nights, Days, and Seasons). This lidar consists of two independent, tuned, pulsed transmitters on the same optical bench using a common 8" receiver telescope. The system measures CO2 abundance and O2 surface pressure in the same column to derive the dry volume mixing ratio (vmr). The system is being tested on an airborne platform up to altitudes of 13 Km. The lidar uses a cw scanning laser, externally pulsed and a fiber amplifier in a Master Oscillator Power Amplifier (MOPA) configuration to measure lineshape, range to scattering surfaces and backscatter profiles. The CO2 operates at 1572.335 nm. The O2 channel uses similar technology but frequency doubles to the O2 A-band absorption, around 765nm. Both lasers are scanned across the absorption feature measuring at a fixed number of discrete (~30) wavelengths per scan around ~300 scans/s. Each output pulse is slightly chirped <12MHz as the laser is tuning. Removing this chirp will improve our ability to infer vertical CO2 distribution from a more accurately measured line shape. A Step Tuned Frequency Locked (STFL) DBR diode laser system has been integrated into the CO2 lidar. Tuning and locking takes a ~30μs and the laser is locked to < ±100KHz. We have the ability to position these pulses anywhere on the absorption line other than within a few MHz of line center. While the telescope and fiber coupling scheme remains unchanged the detectors have been upgraded. The O2 system now uses eight SPCMs in parallel to improve count rates and increase dynamic range. Especially useful when flying over bright surfaces. This will improve our ability to measure the O2 pressure at cloud tops and aid in the determining the vmr above clouds. An HgCdTe e-APD detector with a quantum efficient of >80%, linear over five

  13. Airborne asbestos in public buildings

    SciTech Connect

    Chesson, J.; Hatfield, J.; Schultz, B.; Dutrow, E.; Blake, J. )

    1990-02-01

    The U.S. Environmental Protection Agency sampled air in 49 government-owned buildings (six buildings with no asbestos-containing material, six buildings with asbestos-containing material in generally good condition, and 37 buildings with damaged asbestos-containing material). This is the most comprehensive study to date of airborne asbestos levels in U.S. public buildings during normal building activities. The air outside each building was also sampled. Air samples were analyzed by transmission electron microscopy using a direct transfer preparation technique. The results show an increasing trend in average airborne asbestos levels; outdoor levels are lowest and levels in buildings with damaged asbestos-containing material are highest. However, the measured levels and the differences between indoors and outdoors and between building categories are small in absolute magnitude. Comparable studies from Canada and the UK, although differing in their estimated concentrations, also conclude that while airborne asbestos levels may be elevated in buildings that contain asbestos, levels are generally low. This conclusion does not eliminate the possibility of higher airborne asbestos levels during maintenance or renovation that disturbs the asbestos-containing material.

  14. Airborne particle PM 2.5/PM 10 mass distribution and particle-bound PAH concentrations near a medical waste incinerator

    NASA Astrophysics Data System (ADS)

    Mao, I.-Fang; Chen, Chien-Nan; Lin, Yi-Chang; Chen, Mei-Lien

    This study attempts to determine the influence of air quality in a residential area near a medical waste incineration plant. Ambient air concentrations of polycyclic aromatic hydrocarbons (PAHs), PM 10 and PM 2.5 (PM—particulate matter) were determined by collecting air samples in areas both upwind and downwind of the plant. The differences in air pollutant levels between the study area and a reference area 11 km away from the plant were evaluated. Dichotomous samplers were used for sampling PM 2.5 and PM 10 from ambient air. Two hundred and twenty samples were obtained from the study area, and 100 samples were taken from a reference area. Samples were weighed by an electronic microbalance and concentrations of PM 2.5 and PM 10 were determined. A HPLC equipped with a fluorescence detector was employed to analyze the concentrations of 15 PAHs compounds adsorbed into PM 2.5 and PM 10. The experimental results indicated that the average concentrations of PM 2.5 and PM 10 were 30.34±17.95 and 36.81±20.45 μg m -3, respectively, in the study area, while the average ratio of PM 2.5/PM 10 was 0.82±0.01. The concentrations of PM 2.5 and PM 10 of the study area located downwind of the incinerator were significantly higher than the study area upwind of the incinerator ( P<0.05). The concentration of PAHs in PM 2.5 in the study area was 2.2 times higher than in the reference area ( P<0.05). Furthermore, the benzo( a)pyrene concentrations in PM 2.5 and PM 10 were 0.11±0.05 ng m -3 and 0.12±0.06 ng m -3 in the study area, respectively. The benzo( a)pyrene concentrations of PM 2.5 and PM 10 in the study area were 7 and 5.3 times higher than in the reference area ( P<0.05), respectively. The study indicated that the air quality of PM 2.5, PM 10 and PAHs had significant contamination by air pollutants emitted from a medical waste incineration factory, representing a public health problem for nearby residences, despite the factory being equipped with a modern air pollution

  15. Studies in the system MgO-SiO2-CO2-H2O(I): The activity-product constant of chrysotile

    USGS Publications Warehouse

    Hostetler, P.B.; Christ, C.L.

    1968-01-01

    Chrysotile dissolves congruently in water according to the reaction: Mg3Si2O6(OH)4c + 5H2Ol = 3Mgaq2+ + 6OHaq- + 2H4SiO4aq. Experimental determination of the activity-product constant of chrysotile, Kchr = [Mg2+]3[OH-]6[H4SiO4aq]2, at 90??C, yields the value of Kchr = 10-49.2 ?? 100.5. A synthetic sample and a natural sample from New Idria, California, were used in the determination. Values of Kchr were calculated for temperatures ranging from 0??C to 200??C, using the thermochemical data of King et al. (1967) for chrysotile and antigorite, various solubility data for silica, and ionic partial molal heat capacities estimated by the method of criss and Cobble (1964a). Kchr is 10-54.1 at 0??C, rises to a maximum value of 10-48.5 at approximately 135??C, and is 10-49.1 at 200??C (all values for the three-phase system, chrysotile plus solution plus vapor). The calculated 90??C value is 10-49.1, in excellent agreement with the experimental value; for 25??C, the calculated value is 10-50.8. ?? 1968.

  16. Investigation of off-site airborne transport of lead from a superfund removal action site using lead isotope ratios and concentrations

    USGS Publications Warehouse

    Pribil, Michael J.; Maddaloni, Mark A.; Staiger, Kimberly; Wilson, Eric; Magriples, Nick; Ali, Mustafa; Santella, Dennis

    2014-01-01

    Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil samples were used to investigate the potential for off-site air transport of Pb from a former white Pb processing facility to neighboring residential homes in a six block area on Staten Island, NY. Surface and subsurface soil samples collected on the Jewett White Pb site were found to range from 1.122 to 1.138 for 206Pb/207Pb and 2.393 to 2.411 for 208Pb/207Pb. The off-site surface soil samples collected from residential backyards, train trestle, near site grass patches and background areas varied from 1.144 to 1.196 for 206Pb/207Pb and 2.427 to 2.464 for 208Pb/207Pb. Two soil samples collected along Richmond Terrace, where Jewett site soils accumulated after major rain events, varied from 1.136 to 1.147 for 206Pb/207Pb and 2.407 to 2.419 for 208Pb/207Pb. Lead concentration for on-site surface soil samples ranged from 450 to 8000 ug/g, on-site subsurface soil samples ranged from 90,000 to 240,000 ug/g and off-site samples varied from 380 to 3500 ug/g. Lead concentration and isotopic composition for the Staten Island off-site samples were similar to previously published data for other northeastern US cities and reflect re-suspension and re-mobilization of local accumulated Pb. The considerable differences in both the Pb isotopic composition and Pb concentration of on-site and off-site samples resulted in the ability to geochemically trace the transport of particulate Pb. Data in this study indicate minimal off-site surface transport of Pb from the Jewett site into the neighboring residential area.

  17. Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure

    SciTech Connect

    Bernstein, D.M.; Rogers, R.A.; Sepulveda, R.; Kunzendorf, P.; Bellmann, B.; Ernst, H.; Creutzenberg, O.; Phillips, J.I.

    2015-02-15

    This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation. - Highlights: • Evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology in lung or pleural cavity observed at any time point in the brake-dust groups. • Crocidolite quickly

  18. AIRBORNE MONITORING OF COOLING TOWER EFFLUENTS. VOLUME I. TECHNICAL SUMMARY

    EPA Science Inventory

    MRI conducted an airborne plume monitoring program as part of the Chalk Point Cooling Tower Project. Plume measurement included: temperature, dew point, visibility, turbulence, droplet size distribution and concentration, liquid water content, sodium chloride concentration (NaCl)...

  19. ESTIMATION OF VIABLE AIRBORNE MICROBES DOWNWIND FROM A POINT SOURCE

    EPA Science Inventory

    Modification of the Pasquill atmospheric diffusion equations for estimating viable microbial airborne cell concentrations downwind from a continuous point source is presented. A graphical method is given to estimate the ground level cell concentration given (1) microbial death ra...

  20. Airborne Gamma-Spectrometry in Switzerland

    SciTech Connect

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-07

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of {sup 137}Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  1. Airborne oceanographic lidar system

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The characteristics of an Airborne Oceanographic Lidar (AOL) are given. The AOL system is described and its potential for various measurement applications including bathymetry and fluorosensing is discussed.

  2. Concentration and size of asbestos in water supplies.

    PubMed Central

    Millette, J R; Clark, P J; Pansing, M F; Twyman, J D

    1980-01-01

    A review of the results of over 1500 asbestos analyses from U.S. water supplies suggests that the majority of water consumers are not exposed to asbestos concentrations in their drinking water over 1 x 10(6) fibers per liter. There are, however, some populations that are exposed to waterborne asbestos concentrations over 10 x 10(6) fibers per liter caused by natural erosion, mine processing wastes, waste pile erosion, corrosion of asbestos cement pipe, or disintegration of asbestos tile roofs running into cisterns. The distribution of fiber sizes in the water is dependent on the source of the fibers. The average length of chrysotile fibers found in an asbestos cement distribution system was 4 micrometers, while the average fiber length of chrysotile fibers contributed to a water supply by natural erosion was 1 micrometer. PMID:7389681

  3. Seasonal and spatial variation of trace elements in multi-size airborne particulate matters of Beijing, China: Mass concentration, enrichment characteristics, source apportionment, chemical speciation and bioavailability

    NASA Astrophysics Data System (ADS)

    Gao, Jiajia; Tian, Hezhong; Cheng, Ke; Lu, Long; Wang, Yuxuan; Wu, Ye; Zhu, Chuanyong; Liu, Kaiyun; Zhou, Junrui; Liu, Xingang; Chen, Jing; Hao, Jiming

    2014-12-01

    The seasonal and spatial variation characteristics of 19 elements (Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Sb, Se, Zn) in TSP/PM10/PM2.5 samples were investigated, which were collected from April 2011 to January 2012 simultaneously at an urban downtown site, a traffic roadside site, a suburban site, and a rural site in Beijing. The elevated concentrations of several toxic trace elements (As, Cd, Mn, Ni, Pb, etc.) in particles revealed that the contamination of toxic elements in Beijing could not be neglected. Positive matrix factorization method (PMF) was applied for source apportionment of trace elements in PM, and three factors (crust related sources, combustion sources, and traffic and steel industrial related sources) were identified. Furthermore, the chemical speciation and bioavailability of various elements were identified by applying European Community Bureau of Reference (BCR) procedure. Our results showed that eight toxic elements (As, Cd, Cr, Cu, Ni, Pb, Sb and Zn) exhibited higher mobility in PM2.5 than in PM10. Notably, elements of As, Cd, Pb and Zn were presented with higher mobility than the other elements, and these elements were lightly to release into the environment and easily available to human body. Additionally, As, Cd, Pb and Zn also accounted for higher percentages in the bound to mobile fractions at the central urban areas of Beijing. Therefore, special concerns should be paid to these toxic trace elements which had relatively high mobility in fine particles, when planning and implementing the comprehensive air pollution mitigation policies in Beijing.

  4. Airborne particulate polycyclic aromatic hydrocarbon (PAH) pollution in a background site in the North China Plain: concentration, size distribution, toxicity and sources.

    PubMed

    Zhu, Yanhong; Yang, Lingxiao; Yuan, Qi; Yan, Chao; Dong, Can; Meng, Chuanping; Sui, Xiao; Yao, Lan; Yang, Fei; Lu, Yaling; Wang, Wenxing

    2014-01-01

    The size-fractionated characteristics of particulate polycyclic aromatic hydrocarbons (PAHs) were studied from January 2011 to October 2011 using a Micro-orifice Uniform Deposit Impactor (MOUDI) at the Yellow River Delta National Nature Reserve (YRDNNR), a background site located in the North China Plain. The average annual concentration of total PAHs in the YRDNNR (18.95 ± 16.51 ng/m(3)) was lower than that in the urban areas of China; however, it was much higher than that in other rural or remote sites in developed countries. The dominant PAHs, which were found in each season, were fluorene (5.93%-26.80%), phenanthrene (8.17%-26.52%), fluoranthene (15.23%-27.12%) and pyrene (9.23%-16.31%). A bimodal distribution was found for 3-ring PAHs with peaks at approximately 1.0-1.8 μm and 3.2-5.6 μm; however, 4-6 ring PAHs followed a nearly unimodal distribution, with the highest peak in the 1.0-1.8 μm range. The mass median diameter (MMD) values for the total PAHs averaged 1.404, 1.467, 1.218 and 0.931 μm in spring, summer, autumn and winter, respectively. The toxicity analysis indicated that the carcinogenic potency of particulate PAHs existed primarily in the <1.8 μm size range. Diagnostic ratios and PCA analysis indicated that the PAHs in aerosol particles were mainly derived from coal combustion. In addition, back-trajectory calculations demonstrated that atmospheric PAHs were produced primarily by local anthropogenic sources. PMID:23921366

  5. 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.

  6. Airborne pollen trends in the Iberian Peninsula.

    PubMed

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants. PMID:26803684

  7. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  8. High sensitive airborne radioiodine monitor.

    PubMed

    Ogata, Yoshimune; Yamasaki, Tadashi; Hanafusa, Ryuji

    2013-11-01

    Airborne radioiodine monitoring includes a problem in that commercial radioactive gas monitors have inadequate sensitivity. To solve this problem, we designed a highly sensitive monitoring system. The higher counting efficiency and lower background made it possible to perform the low-level monitoring. The characteristics of the system were investigated using gaseous (125)I. The minimum detectable activity concentration was 1 × 10(-4)Bq cm(-3) for 1 min counting, which is one tenth of the legal limit for the radiation controlled areas in Japan. PMID:23602709

  9. Toolsets for Airborne Data

    Atmospheric Science Data Center

    2015-04-02

    article title:  Toolsets for Airborne Data     View larger image The ... limit of detection values. Prior to accessing the TAD Web Application ( https://tad.larc.nasa.gov ) for the first time, users must ...

  10. The airborne laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven; Schall, Harold; Shattuck, Paul

    2007-05-01

    The Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the current program status.

  11. EVALUATING AND OPTIMIZING ELECTRON MICROSCOPE METHODS FOR CHARACTERIZING AIRBORNE ASBESTOS

    EPA Science Inventory

    Evaluation of EM methods for measuring airborne asbestos fiber concentrations and size distributions was carried out by studying a large number of variables and subprocedures in a five-phase program using elaborate statistically designed experiments. Observations were analyzed by...

  12. Airborne Microalgae: Insights, Opportunities, and Challenges.

    PubMed

    Tesson, Sylvie V M; Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-04-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  13. Airborne Microalgae: Insights, Opportunities, and Challenges

    PubMed Central

    Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-01-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  14. The Airborne Laser

    NASA Astrophysics Data System (ADS)

    Lamberson, Steven E.

    2002-09-01

    The US Air Force Airborne Laser (ABL) is an airborne, megawatt-class laser system with a state-of-the-art atmospheric compensation system to destroy enemy ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success.

  15. 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.

  16. NASA Airborne Lidar July 1991

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar July 1991 Data from the 1991 NASA Langley Airborne Lidar flights following the eruption of Pinatubo in July ... and Osborn [1992a, 1992b]. Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  17. NASA Airborne Lidar May 1992

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar May 1992 An airborne Nd:YAG (532 nm) lidar was operated by the NASA Langley Research Center about a year following the June 1991 eruption of ... Osborn [1992a, 1992b].  Project Title:  NASA Airborne Lidar Discipline:  Field Campaigns ...

  18. Airborne antenna pattern calculations

    NASA Technical Reports Server (NTRS)

    Knerr, T. J.; Schaffner, P. R.; Mielke, R. R.; Gilreath, M. C.

    1980-01-01

    A procedure for numerically calculating radiation patterns of fuselage-mounted airborne antennas using the Volumetric Pattern Analysis Program is presented. Special attention is given to aircraft modeling. An actual case study involving a large commercial aircraft is included to illustrate the analysis procedure.

  19. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

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

  20. Airborne Fraunhofer Line Discriminator

    NASA Technical Reports Server (NTRS)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  1. Airborne Remote Sensing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA imaging technology has provided the basis for a commercial agricultural reconnaissance service. AG-RECON furnishes information from airborne sensors, aerial photographs and satellite and ground databases to farmers, foresters, geologists, etc. This service produces color "maps" of Earth conditions, which enable clients to detect crop color changes or temperature changes that may indicate fire damage or pest stress problems.

  2. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  3. Comparison of Calidria chrysotile asbestos to pure tremolite: final results of the inhalation biopersistence and histopathology examination following short-term exposure.

    PubMed

    Bernstein, David M; Chevalier, Jörg; Smith, Paul

    2005-08-01

    Calidria chrysotile asbestos, which is a serpentine mineral, has been shown to be considerably less biopersistent than the durable amphibole mineral tremolite asbestos, which persists once deposited in the lung. The initial results of this inhalation biopersistence study in rats that demonstrates this difference were reported in Bernstein et al. (2003). This article presents the full results through 1 yr after cessation of the 5-day exposure. This study was based upon the recommendations of the European Commission (EC) Interim Protocol for the Inhalation Biopersistence of synthetic mineral fibers (Bernstein & Riego-Sintes, 1999). In addition, the histopathological response in the lung was evaluated following exposure. In order to quantify the dynamics and rate by which these fibers are removed from the lung, the biopersistence of a sample of commercial-grade chrysotile from the Coalinga mine in New Idria, CA, of the type Calidria RG144 and that of a long-fiber tremolite were studied. For synthetic vitreous fibers, the biopersistence of the fibers longer than 20 microm has been found to be directly related to their potential to cause disease. This study was designed to determine lung clearance (biopersistence) and the histopathological response. As the long fibers have been shown to have the greatest potential for pathogenicity, the aerosol generation technique was designed to maximize the number of long respirable fibers. The chrysotile samples were specifically chosen to have 200 fibers/cm3 longer than 20 microm in length present in the exposure aerosol. These longer fibers were found to be largely composed of multiple shorter fibrils. The tremolite samples were chosen to have 100 fibers/cm3 longer than 20 microm in length present in the exposure aerosol. Calidria chrysotile has been found to be one of the most rapidly cleared mineral fibers from the lung. The fibers longer than 20 microm in length are cleared with a half-time of 7 h. By 2 days postexposure all

  4. Exposure level and distribution characteristics of airborne bacteria and fungi in Seoul metropolitan subway stations.

    PubMed

    Kim, Ki Youn; Kim, Yoon Shin; Kim, Daekeun; Kim, Hyeon Tae

    2011-01-01

    The exposure level and distribution characteristics of airborne bacteria and fungi were assessed in the workers' activity areas (station office, bedroom, ticket office and driver's seat) and passengers' activity areas (station precinct, inside the passenger carriage, and platform) of the Seoul metropolitan subway. Among investigated areas, the levels of airborne bacteria and fungi in the workers' bedroom and station precincts were relatively high. No significant difference was found in the concentration of airborne bacteria and fungi between the underground and above ground activity areas of the subway. The genera identified in all subway activity areas with a 5% or greater detection rate were Staphylococcus, Micrococcus, Bacillus and Corynebacterium for airborne bacteria and Penicillium, Cladosporium, Chrysosporium, Aspergillus for airborne fungi. Staphylococcus and Micrococcus comprised over 50% of the total airborne bacteria and Penicillium and Cladosporium comprised over 60% of the total airborne fungi, thus these four genera are the predominant genera in the subway station. PMID:21173524

  5. [Air-borne disease].

    PubMed

    Lameiro Vilariño, Carmen; del Campo Pérez, Victor M; Alonso Bürger, Susana; Felpeto Nodar, Irene; Guimarey Pérez, Rosa; Pérez Alvarellos, Alberto

    2003-11-01

    Respiratory protection is a factor which worries nursing professionals who take care of patients susceptible of transmitting microorganisms through the air more as every day passes. This type of protection covers the use of surgical or hygienic masks against the transmission of infection by airborne drops to the use of highly effective masks or respirators against the transmission of airborne diseases such as tuberculosis or SARS, a recently discovered disease. The adequate choice of this protective device and its correct use are fundamental in order to have an effective protection for exposed personnel. The authors summarize the main protective respiratory devices used by health workers, their characteristics and degree of effectiveness, as well as the circumstances under which each device is indicated for use. PMID:14705591

  6. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  7. MLS airborne antenna research

    NASA Technical Reports Server (NTRS)

    Yu, C. L.; Burnside, W. D.

    1975-01-01

    The geometrical theory of diffraction was used to analyze the elevation plane pattern of on-aircraft antennas. The radiation patterns for basic elements (infinitesimal dipole, circumferential and axial slot) mounted on fuselage of various aircrafts with or without radome included were calculated and compared well with experimental results. Error phase plots were also presented. The effects of radiation patterns and error phase plots on the polarization selection for the MLS airborne antenna are discussed.

  8. Airborne field strength monitoring

    NASA Astrophysics Data System (ADS)

    Bredemeyer, J.; Kleine-Ostmann, T.; Schrader, T.; Münter, K.; Ritter, J.

    2007-06-01

    In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

  9. 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. PMID:7005667

  10. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D.; Schmitt, Michael J.; Jones, Warren F.

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  11. 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

  12. How conflicted authors undermine the World Health Organization (WHO) campaign to stop all use of asbestos: spotlight on studies showing that chrysotile is carcinogenic and facilitates other non-cancer asbestos-related diseases

    PubMed Central

    Baur, Xaver; Soskolne, Colin L; Lemen, Richard A; Schneider, Joachim; Woitowitz, Hans-Joachim; Budnik, Lygia Therese

    2015-01-01

    The silicate mineral asbestos is categorized into two main groups based on fiber structure: serpentine asbestos (chrysotile) and amphibole asbestos (crocidolite, amosite, anthophyllite, tremolite, and actinolite). Chrysotile is used in more than 2 000 applications and is especially prevalent in the construction industry. Although its use is banned or restricted in more than 52 countries, an estimated 107 000 workers die from asbestos exposure each year, and approximately 125 million workers continue to be exposed. Furthermore, ambient exposures persist to which the public is exposed, globally. Today, the primary controversies regarding the use of asbestos are the potencies of different types of asbestos, as opposed whether or not asbestos causes morbidity and mortality. The asbestos industry has promoted and funded research based on selected literature, ignoring both clinical and scientific knowledge. In this piece, we highlight a prominent example of a conflicted publication that sought to undermine the World Health Organization (WHO) campaign to stop the use of all forms of asbestos, including chrysotile asbestos. Independent and rigorous scientific data provide sufficient evidence that chrysotile asbestos, like other forms of asbestos, is a cause of asbestos-related morbidity and premature mortality PMID:25729927

  13. 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

  14. Airborne radioactive contamination monitoring

    SciTech Connect

    Whitley, C.R.; Adams, J.R.; Bounds, J.A.; MacArthur, D.W.

    1996-03-01

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination.

  15. Airborne Raman lidar

    NASA Astrophysics Data System (ADS)

    Heaps, Wm. S.; Burris, J.

    1996-12-01

    We designed and tested an airborne lidar system using Raman scattering to make simultaneous measurements of methane, water vapor, and temperature in a series of flights on a NASA-operated C-130 aircraft. We present the results for methane detection, which show that the instrument has the requisite sensitivity to atmospheric trace gases. Ultimately these measurements can be used to examine the transport of chemically processed air from within the polar vortex to mid-latitudinal regions and the exchange of stratospheric air between tropical and mid-latitudinal regions.

  16. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The Airborne Oceanographic Lidar (AOL), a spatially scanning range-gated device installed on board a NASA C-54 aircraft, is described. The AOL system is capable of measuring topographical relief or water depth (bathymetry) with a range resolution of plus or minus 0.3 m in the vertical dimension. The system may also be used to measure fluorescent spectral signatures from 3500 to 8000 A with a resolution of 100 A. Potential applications of the AOL, including sea state measurements, water transparency assessments, oil spill identification, effluent identification and crop cover assessment are also mentioned.

  17. Airborne ballistic camera tracking systems

    NASA Technical Reports Server (NTRS)

    Redish, W. L.

    1976-01-01

    An operational airborne ballistic camera tracking system was tested for operational and data reduction feasibility. The acquisition and data processing requirements of the system are discussed. Suggestions for future improvements are also noted. A description of the data reduction mathematics is outlined. Results from a successful reentry test mission are tabulated. The test mission indicated that airborne ballistic camera tracking systems are feasible.

  18. More on the dynamics of dust generation: the effects of mixing and sanding chrysotile, calcium carbonate, and other components on the characteristics of joint-compound dusts.

    PubMed

    Berman, D Wayne; Brorby, Gregory P; Sheehan, Patrick J; Bogen, Kenneth T; Holm, Stewart E

    2012-08-01

    An ongoing research effort designed to reconstruct the character of historical exposures associated with use of chrysotile-containing joint compounds naturally raised questions concerning how the character (e.g. particle size distributions) of dusts generated from use of recreated materials compares to dusts from similar materials manufactured historically. This also provided an opportunity to further explore the relative degree that the characteristics of dusts generated from a bulk material are mediated by the properties of the bulk material versus the mechanical processes applied to the bulk material by which the dust is generated. In the current study, the characteristics of dusts generated from a recreated ready mix and recreated dry mix were compared to each other, to dusts from a historical dry mix, and to dusts from the commercial chrysotile fiber (JM 7RF3) used in the recreated materials. The effect of sanding on the character of dusts generated from these materials was also explored. Dusts from the dry materials studied were generated and captured for analysis in a dust generator-elutriator. The recreated and historical joint compounds were also prepared, applied to drywall, and sanded inside sealed bags so that the particles produced from sanding could be introduced into the elutriator and captured for analysis. Comparisons of fiber size distributions in dusts from these materials suggest that dust from commercial fiber is different from dusts generated from the joint compounds, which are mixtures, and the differences persist whether the materials are sanded or not. Differences were also observed between sanded recreated ready mix and either the recreated dry mix or a historical dry mix, again whether sanded or not. In all cases, however, such differences disappeared when variances obtained from surrogate data were used to better represent the 'irreducible variation' of these materials. Even using the smaller study-specific variances, no differences were

  19. Airborne transmission of lyssaviruses.

    PubMed

    Johnson, N; Phillpotts, R; Fooks, A R

    2006-06-01

    In 2002, a Scottish bat conservationist developed a rabies-like disease and subsequently died. This was caused by infection with European bat lyssavirus 2 (EBLV-2), a virus closely related to Rabies virus (RABV). The source of this infection and the means of transmission have not yet been confirmed. In this study, the hypothesis that lyssaviruses, particularly RABV and the bat variant EBLV-2, might be transmitted via the airborne route was tested. Mice were challenged via direct introduction of lyssavirus into the nasal passages. Two hours after intranasal challenge with a mouse-adapted strain of RABV (Challenge Virus Standard), viral RNA was detectable in the tongue, lungs and stomach. All of the mice challenged by direct intranasal inoculation developed disease signs by 7 days post-infection. Two out of five mice challenged by direct intranasal inoculation of EBLV-2 developed disease between 16 and 19 days post-infection. In addition, a simple apparatus was evaluated in which mice could be exposed experimentally to infectious doses of lyssavirus from an aerosol. Using this approach, mice challenged with RABV, but not those challenged with EBLV-2, were highly susceptible to infection by inhalation. These data support the hypothesis that lyssaviruses, and RABV in particular, can be spread by airborne transmission in a dose-dependent manner. This could present a particular hazard to personnel exposed to aerosols of infectious RABV following accidental release in a laboratory environment. PMID:16687600

  20. Airborne electromagnetic hydrocarbon mapping in Mozambique

    NASA Astrophysics Data System (ADS)

    Pfaffhuber, Andreas A.; Monstad, Ståle; Rudd, Jonathan

    2009-09-01

    The Inhaminga hydrocarbon exploration licence in central Mozambique sets the location for a multi-method airborne geophysical survey. The size of the Inhaminga block, spanning some 16500km2 from Beira to the Zambezi, limited available data and a tight exploration schedule made an airborne survey attractive for the exploration portfolio. The aim of the survey was to map hydrocarbon seepage zones based on the evidence that seepage may create resistivity, radiometric and sometimes magnetic anomalies. The survey involved a helicopter-borne time domain electromagnetic induction system (AEM) and a fixed wing magnetic gradiometer and radiometer. Our data analysis highlights an anomaly extending some tens of kilometres through the survey area along the eastern margin of the Urema Graben. The area is imaged by AEM as a shallow resistive unit below a strong surface conductor and shows high Uranium and low Potassium concentrations (normalised to mean Thorium ratios). A seismic dimming zone on a 2D seismic line crossing the area coincides with the resistivity and radiometric anomaly. The geological exploration model expects seepage to be linked to the graben fault systems and an active seep has been sampled close to the anomaly. We thus interpret this anomaly to be associated with a gas seepage zone. Further geological ground work and seismic investigations are planned to assess this lead. Airborne data has further improved the general understanding of the regional geology allowing spatial mapping of faults and other features from 2D seismic lines crossing the survey area.

  1. Characterization of Airborne Bacteria at an Underground Subway Station

    PubMed Central

    Dybwad, Marius; Granum, Per Einar; Bruheim, Per

    2012-01-01

    The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization–time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

  2. Characterization of airborne bacteria at an underground subway station.

    PubMed

    Dybwad, Marius; Granum, Per Einar; Bruheim, Per; Blatny, Janet Martha

    2012-03-01

    The reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization-time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the genera Bacillus, Micrococcus, and Staphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers. PMID:22247150

  3. Processor architecture for airborne SAR systems

    NASA Technical Reports Server (NTRS)

    Glass, C. M.

    1983-01-01

    Digital processors for spaceborne imaging radars and application of the technology developed for airborne SAR systems are considered. Transferring algorithms and implementation techniques from airborne to spaceborne SAR processors offers obvious advantages. The following topics are discussed: (1) a quantification of the differences in processing algorithms for airborne and spaceborne SARs; and (2) an overview of three processors for airborne SAR systems.

  4. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  5. Airborne Wind Turbine

    SciTech Connect

    2010-09-01

    Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.

  6. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  7. Biophysical influence of airborne carbon nanomaterials on natural pulmonary surfactant.

    PubMed

    Valle, Russell P; Wu, Tony; Zuo, Yi Y

    2015-05-26

    Inhalation of nanoparticles (NP), including lightweight airborne carbonaceous nanomaterials (CNM), poses a direct and systemic health threat to those who handle them. Inhaled NP penetrate deep pulmonary structures in which they first interact with the pulmonary surfactant (PS) lining at the alveolar air-water interface. In spite of many research efforts, there is a gap of knowledge between in vitro biophysical study and in vivo inhalation toxicology since all existing biophysical models handle NP-PS interactions in the liquid phase. This technical limitation, inherent in current in vitro methodologies, makes it impossible to simulate how airborne NP deposit at the PS film and interact with it. Existing in vitro NP-PS studies using liquid-suspended particles have been shown to artificially inflate the no-observed adverse effect level of NP exposure when compared to in vivo inhalation studies and international occupational exposure limits (OELs). Here, we developed an in vitro methodology called the constrained drop surfactometer (CDS) to quantitatively study PS inhibition by airborne CNM. We show that airborne multiwalled carbon nanotubes and graphene nanoplatelets induce a concentration-dependent PS inhibition under physiologically relevant conditions. The CNM aerosol concentrations controlled in the CDS are comparable to those defined in international OELs. Development of the CDS has the potential to advance our understanding of how submicron airborne nanomaterials affect the PS lining of the lung. PMID:25929264

  8. LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS

    EPA Science Inventory

    The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...

  9. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... centimeter of air (f/cc). (ii) Excursion limit. No miner shall be exposed at any time to airborne concentrations of asbestos in excess of 1 fiber per cubic centimeter of air (f/cc) as averaged over a...

  10. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... centimeter of air (f/cc). (ii) Excursion limit. No miner shall be exposed at any time to airborne concentrations of asbestos in excess of 1 fiber per cubic centimeter of air (f/cc) as averaged over a...

  11. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... contrast microscopy (PCM) using the OSHA Reference Method in OSHA's asbestos standard found in 29 CFR 1910... full-shift airborne concentration of 0.1 fiber per cubic centimeter of air (f/cc). (ii) Excursion limit... cubic centimeter of air (f/cc) as averaged over a sampling period of 30 minutes. (3) Measurement...

  12. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... contrast microscopy (PCM) using the OSHA Reference Method in OSHA's asbestos standard found in 29 CFR 1910... full-shift airborne concentration of 0.1 fiber per cubic centimeter of air (f/cc). (ii) Excursion limit... cubic centimeter of air (f/cc) as averaged over a sampling period of 30 minutes. (3) Measurement...

  13. Total contribution of airborne lead to blood lead.

    PubMed Central

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone. PMID:3970881

  14. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... centimeter of air (f/cc). (ii) Excursion limit. No miner shall be exposed at any time to airborne concentrations of asbestos in excess of 1 fiber per cubic centimeter of air (f/cc) as averaged over a...

  15. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... asbestos standard found in 29 CFR 1910.1001, Appendix A, or a method at least equivalent to that method in... centimeter of air (f/cc). (ii) Excursion limit. No miner shall be exposed at any time to airborne concentrations of asbestos in excess of 1 fiber per cubic centimeter of air (f/cc) as averaged over a...

  16. Airborne endotoxin in fine particulate matter in Beijing

    NASA Astrophysics Data System (ADS)

    Guan, Tianjia; Yao, Maosheng; Wang, Junxia; Fang, Yanhua; Hu, Songhe; Wang, Yan; Dutta, Anindita; Yang, Junnan; Wu, Yusheng; Hu, Min; Zhu, Tong

    2014-11-01

    Endotoxin is an important biological component of particulate matter (PM) which, upon inhalation, can induce adverse health effects, and also possibly complicate the diseases in combination with other pollutants. From 1 March 2012 to 27 February 2013 we collected air samples using quartz filters daily for the quantification of airborne endotoxin and also fine PM (PM2.5) in Beijing, China. The geometric means for endotoxin concentration and the fraction of endotoxin in PM were 0.65 EU/m3 (range: 0.10-75.02) and 10.25 EU/mg PM2.5 (range: 0.38-1627.29), respectively. The endotoxin concentrations were shown to vary greatly with seasons, typically with high values in the spring and winter seasons. Temperature and relative humidity, as well as concentrations of sulfur dioxide and nitrogen oxides were found to be significantly correlated with airborne endotoxin concentrations (p < 0.05). Additionally, positive correlations were also detected between endotoxin concentrations and natural sources of Na+, K+, Mg2+, and F-, while negative correlations were observed between endotoxin concentrations and anthropogenic sources of P, Co, Zn, As, and Tl. Oxidative potential analysis revealed that endotoxin concentrations were positively correlated with reactive oxygen species (ROS), but not dithiothreitol (DTT) of PM. This study provided the first continuous time series of airborne endotoxin concentrations in Beijing, and identifies its potential associations with atmospheric factors. The information developed here can assist in the assessment of health effects of air pollution in Beijing.

  17. 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

  18. Exposure to airborne asbestos in buildings

    SciTech Connect

    Lee, R.J.; Van Orden, D.R.; Corn, M.; Crump, K.S. )

    1992-08-01

    The concentration of airborne asbestos in buildings and its implication for the health of building occupants is a major public health issue. A total of 2892 air samples from 315 public, commercial, residential, school, and university buildings has been analyzed by transmission electron microscopy. The buildings that were surveyed were the subject of litigation related to suits alleging the general building occupants were exposed to a potential health hazard as a result of exposure to the presence of asbestos containing materials (ACM). The average concentration of all asbestos structures was 0.02 structures/ml (s/ml) and the average concentration of asbestos greater than or equal to 5 microns long was 0.00013 fibers/ml (f/ml). The concentration of asbestos was higher in schools than in other buildings. In 48% of indoor samples and 75% of outdoor samples, no asbestos fibers were detected. The observed airborne concentration in 74% of the indoor samples and 96% of the outdoor samples is below the Asbestos Hazard Emergency Response Act clearance level of 0.01 s/ml. Finally, using those fibers which could be seen optically, all indoor samples and all outdoor samples are below the Occupational Safety and Health Administration permissible exposure level of 0.1 f/ml for fibers greater than or equal to 5 microns in length. These results provide substantive verification of the findings of the U.S. Environmental Protection Agency public building study which found very low ambient concentrations of asbestos fibers in buildings with ACM, irrespective of the condition of the material in the buildings.

  19. Airborne GLM Simulator (FEGS)

    NASA Astrophysics Data System (ADS)

    Quick, M.; Blakeslee, R. J.; Christian, H. J., Jr.; Stewart, M. F.; Podgorny, S.; Corredor, D.

    2015-12-01

    Real time lightning observations have proven to be useful for advanced warning and now-casting of severe weather events. In anticipation of the launch of the Geostationary Lightning Mapper (GLM) onboard GOES-R that will provide continuous real time observations of total (both cloud and ground) lightning, the Fly's Eye GLM Simulator (FEGS) is in production. FEGS is an airborne instrument designed to provide cal/val measurements for GLM from high altitude aircraft. It consists of a 5 x 5 array of telescopes each with a narrow passband filter to isolate the 777.4 nm neutral oxygen emission triplet radiated by lightning. The telescopes will measure the optical radiance emitted by lightning that is transmitted through the cloud top with a temporal resolution of 10 μs. When integrated on the NASA ER-2 aircraft, the FEGS array with its 90° field-of-view will observe a cloud top area nearly equal to a single GLM pixel. This design will allow FEGS to determine the temporal and spatial variation of light that contributes to a GLM event detection. In addition to the primary telescope array, the instrument includes 5 supplementary optical channels that observe alternate spectral emission features and will enable the use of FEGS for interesting lightning physics applications. Here we present an up-to-date summary of the project and a description of its scientific applications.

  20. Airborne rescue system

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1991-01-01

    The airborne rescue system includes a boom with telescoping members for extending a line and collar to a rescue victim. The boom extends beyond the tip of the helicopter rotor so that the victim may avoid the rotor downwash. The rescue line is played out and reeled in by winch. The line is temporarily retained under the boom. When the boom is extended, the rescue line passes through clips. When the victim dons the collar and the tension in the line reaches a predetermined level, the clips open and release the line from the boom. Then the rescue line can form a straight line between the victim and the winch, and the victim can be lifted to the helicopter. A translator is utilized to push out or pull in the telescoping members. The translator comprises a tape and a rope. Inside the telescoping members the tape is curled around the rope and the tape has a tube-like configuration. The tape and rope are provided from supply spools.

  1. Control of airborne fungal spores in a university hospital

    SciTech Connect

    Streifel, A.J.; Vesley, D. ); Rhame, F.S. ); Murray, B. )

    1989-01-01

    A new university hospital was designed to maximize the air quality protection of severely compromised patients undergoing transplantation or treatment for malignant disorders. The entire hospital was designed as a sealed building with two filter systems having >95% efficiencies for 1.0 {mu}m particles. Controlled airflow and isolation of the most severely compromised patients were also design features. Air quality monitoring of particles and airborne fungi demonstrate effective control in the patient environment. The results show the areas with the greatest control of personnel and air changes have the lowest airborne concentrations of fungi and the smallest particles. Larger indoor airborne particle ranking indicate highest levels depending on local human activity, air changes rates, or filtration efficiency.

  2. Airborne Laser Polar Nephelometer

    NASA Technical Reports Server (NTRS)

    Grams, Gerald W.

    1973-01-01

    A polar nephelometer has been developed at NCAR to measure the angular variation of the intensity of light scattered by air molecules and particles. The system has been designed for airborne measurements using outside air ducted through a 5-cm diameter airflow tube; the sample volume is that which is common to the intersection of a collimated source beam and the detector field of view within the airflow tube. The source is a linearly polarized helium-neon laser beam. The optical system defines a collimated field-of-view (0.5deg half-angle) through a series of diaphragms located behind a I72-mm focal length objective lens. A photomultiplier tube is located immediately behind an aperture in the focal plane of the objective lens. The laser beam is mechanically chopped (on-off) at a rate of 5 Hz; a two-channel pulse counter, synchronized to the laser output, measures the photomultiplier pulse rate with the light beam both on and off. The difference in these measured pulse rates is directly proportional to the intensity of the scattered light from the volume common to the intersection of the laser beam and the detector field-of-view. Measurements can be made at scattering angles from 15deg to 165deg with reference to the direction of propagation of the light beam. Intermediate angles are obtained by selecting the angular increments desired between these extreme angles (any multiple of 0.1deg can be selected for the angular increment; 5deg is used in normal operation). Pulses provided by digital circuits control a stepping motor which sequentially rotates the detector by pre-selected angular increments. The synchronous photon-counting system automatically begins measurement of the scattered-light intensity immediately after the rotation to a new angle has been completed. The instrument has been flown on the NASA Convair 990 airborne laboratory to obtain data on the complex index of refraction of atmospheric aerosols. A particle impaction device is operated simultaneously

  3. Potential airborne release from soil-working operations in a contaminated area

    SciTech Connect

    Sutter, S.L.

    1980-08-01

    Experiments were performed to provide an indication of how much material could be made airborne during soil-working operations in a contaminated area. Approximately 50 kg of contaminated soil were collected, dried, and mixed, and particle size distribution and /sup 137/Cs content were characterized. In four experiments performed in a 2 ft x 2 ft wind tunnel at the Radioactive Aerosol Release Test Facility, soil was pumped into an airstream moving at 3.2, 10.4, 15.2, and 20 mph. These experiments were designed to maximize airborne releases by fluidizing the soil as it was pumped into the wind tunnel. Thus the airborne releases should represent upper limit values for soil-working operations. Airborne concentration and particle size samples were collected and all of the material deposited downstream was collected to calculate a mass balance. The fraction airborne was calculated using these measurements.

  4. Physico-chemical characteristics of visibility impairment by airborne pollen in an urban area

    NASA Astrophysics Data System (ADS)

    Kim, Kyung W.

    The number of airborne pollen produced from plants is visible as a haze mixed with urban air pollution in an urban area when atmospheric conditions are proper for pollination of pollen from April to May in Korea. The big loading of airborne pollen can cause further visibility degradation in an urban area. In order to investigate physico-chemical characteristics of visibility impairment by airborne pollen, chemical aerosol measurements, optical aerosol monitoring, and scenic monitoring were performed during the intensive monitoring period from April 19 to May 2, 2005 in the urban area of Seoul, Korea. The particles collected on filters were examined with a scanning electron microscope (SEM) interfaced with an energy dispersive X-ray analysis to characterize size, elemental composition, and count of airborne pollen. During the airborne pollen period, the daily averaged number concentrations of airborne pollen; P and P were calculated to be 8.4±6.9 and 113.7±91.1 m -3, respectively. The daily averaged light extinction coefficient ( bext), light scattering coefficient for open path ( bscat), light scattering coefficient for dry particle in the fine regime ( bscat,fine), and light absorption coefficient in the fine regime ( babs,fine) were measured to be 459±267, 357±214, 263±165, and 44±30 Mm -1, respectively. And mass concentration of PM 2.5 and PM 10 were measured to be 46.5±29.1 and 97.0±41.7 μg m -3. The average light absorption coefficient by airborne pollen was estimated to be about 30 M m -1 and the average light scattering coefficient by airborne pollen was estimated to be 67±57 Mm -1. During the airborne pollen period the average contribution of airborne pollen to visibility impairment was roughly estimated to be 19-25%.

  5. Airborne laser topographic mapping results

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Collins, J. G.; Link, L. E.; Swift, R. N.; Butler, M. L.

    1984-01-01

    The results of terrain mapping experiments utilizing the National Aeronautics and Space Administration (NASA) Airborne Oceanographic Lidar (AOL) over forested areas are presented. The flight tests were conducted as part of a joint NASA/U.S. Army Corps of Engineers (CE) investigation aimed at evaluating the potential of an airborne laser ranging system to provide cross-sectional topographic data on flood plains that are difficult and expensive to survey using conventional techniques. The data described in this paper were obtained in the Wolf River Basin located near Memphis, TN. Results from surveys conducted under winter 'leaves off' and summer 'leaves on' conditions, aspects of day and night operation, and data obtained from decidous and coniferous tree types are compared. Data processing techniques are reviewed. Conclusions relative to accuracy and present limitations of the AOL, and airborne lidar systems in general, to terrain mapping over forested areas are discussed.

  6. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT RESEARCH PLAN

    EPA Science Inventory

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

  7. [Airborne fungal community composition in indoor environments in Beijing].

    PubMed

    Fang, Zhi-guo; Ouyang, Zhi-yun; Liu, Peng; Sun, Li; Wang, Xiao-yong

    2013-05-01

    Indoor environmental quality has significant effects on human health. It is reported that adults in China spent about 80%-90% of their time in indoor environments, and a number of physically handicapped people such as the elderly and infants stayed in the room even up to 95% of their total time. Moreover, air conditioner in indoor environments becomes more and more important in modern life, and a closed circulatory system can be formed among human body, room and air conditioner in indoor environments with an air conditioner, which can make the microbes such as bacteria, viruses and mold indoors propagate rapidly or abundantly. Therefore, studies on the microbial pollution in the air at places such as mall, classroom, office, and family home have been the research hotspots recently. In the present study, the community composition and concentration variation pattern of airborne fungi were investigated from Nov 2009 to Oct 2010 in 31 family homes with children in Beijing. Results showed that 24 generas of airborne fungi in family homes were identified from 225 isolates. The most common fungi were Penicillium, Cladosporium, Aspergillus, Alternaria and Phoma. The frequency of Penicillium, Cladosporium, Aspergillus, Alternaria and Monilia was much higher than those of other fungal genera in family home, and the frequency of Penicillium was more than 90%. As for the concentration percentage, airborne fungi with most high concentrations were Penicillium, Cladosporium, Aspergillus, No-sporing, and Alternaria, and totally accounted for more than 65.0%. Penicillium contributed to 32.2% of the total airborne fungi in family homes. In the 31 family homes selected, the fungal concentration in the air ranged from 62-3 498 CFU x m(-3), and the mean concentration was 837 CFU x m(-3). Seasonal variation pattern of total fungi, and Cladosporium, Aspergillus, Alternaria concentration was consistent, and the highest fungal concentration was observed in summer, followed by spring and

  8. Exposure to airborne endotoxins among sewer workers: an exploratory study.

    PubMed

    Duquenne, Philippe; Ambroise, Denis; Görner, Pierre; Clerc, Frédéric; Greff-Mirguet, Guylaine

    2014-04-01

    Exploratory bioaerosol sampling was performed in order to assess exposure to airborne endotoxins during sewer work. Personal samples were collected in underground sewer pipes using 37-mm closed-face cassettes containing fibreglass filters (CFC-FG method) or polycarbonate filters (CFC-PC method). Endotoxins were quantified using the limulus amoebocyte lysate assay. Concentrations of airborne endotoxins at sewer workplaces (16-420 EU m(-3)) were higher than those measured outside the sewer network (0.6-122 EU m(-3)). Sewer worker exposure to airborne endotoxins depended on the workplace and on the tasks. Exposure levels were the highest for tasks involving agitation of water and matter, especially for 'chamber cleanup' and 'pipes cleanup' with a high-pressure water jet. Airborne endotoxin levels at the workplace tended to be higher when CFC-FG was used as the sampling method rather than CFC-PC. The adjusted mean of the measured concentrations for CFC-PC represents 57% of the mean observed with CFC-FG. The number of samples collected in the descriptive study was too low for drawing definitive conclusions and further exposure investigations are needed. Therefore, our exploratory study provides new exposure data for the insufficiently documented sewer working environment and it would be useful for designing larger exposures studies. PMID:24470536

  9. NASA Airborne Lidar 1982-1984 Flights

    Atmospheric Science Data Center

    2016-05-26

    NASA Airborne Lidar 1982-1984 Flights Data from the 1982 NASA Langley Airborne Lidar flights following the eruption of El Chichon ... continuing to January 1984. Transcribed from the following NASA Tech Reports: McCormick, M. P., and M. T. Osborn, Airborne lidar ...

  10. How are the physical and chemical properties of chrysotile asbestos altered by a 10-year residence in water and up to 5 days in simulated stomach acid

    SciTech Connect

    Seshan, K.

    1983-11-01

    Various tests and techniques were used to study the effect of exposure to simulated gastric juices as well as the effect of long term storage in water on asbestos fibers. Changes were noted in the physical, chemical and surface properties of chrysotile asbestos as a result of exposure to water, strong acids, and simulated gastric juices. The charge on the surface (the zeta potential) was changed from positive to negative; the surface became silica-like; and the magnesium was lost from the asbestos fibers on exposure to water and acid. The smaller the fiber diameter, the faster the loss of the magnesium. Notable among the changes in physical properties is a change in the refractive index. Asbestos exposed to acids or water may not be detectable using the dispersion staining techniques that identify asbestos based on the refractive index. Other physical property changes include the destruction of the gross crystallinity of the fibers. The x-ray diffraction signal disappears when fibers are exposed to acid. The fibers may still be detected by electron diffraction. Upon acid exposure, the magnesium ions are leached out, leaving a magnesium-free silica network. A positive ion, possibly the proton or the hydronium ion, replaces the lost magnesium ion. 20 references, 11 figures, 2 tables.

  11. Asthmatic responses to airborne acid aerosols.

    PubMed Central

    Ostro, B D; Lipsett, M J; Wiener, M B; Selner, J C

    1991-01-01

    BACKGROUND: Controlled exposure studies suggest that asthmatics may be more sensitive to the respiratory effects of acidic aerosols than individuals without asthma. This study investigates whether acidic aerosols and other air pollutants are associated with respiratory symptoms in free-living asthmatics. METHODS: Daily concentrations of hydrogen ion (H+), nitric acid, fine particulates, sulfates and nitrates were obtained during an intensive air monitoring effort in Denver, Colorado, in the winter of 1987-88. A panel of 207 asthmatics recorded respiratory symptoms, frequency of medication use, and related information in daily diaries. We used a multiple regression time-series model to analyze which air pollutants, if any, were associated with health outcomes reported by study participants. RESULTS: Airborne H+ was found to be significantly associated with several indicators of asthma status, including moderate or severe cough and shortness of breath. Cough was also associated with fine particulates, and shortness of breath with sulfates. Incorporating the participants' time spent outside and exercise intensity into the daily measure of exposure strengthened the association between these pollutants and asthmatic symptoms. Nitric acid and nitrates were not significantly associated with any respiratory symptom analyzed. CONCLUSIONS: In this population of asthmatics, several outdoor air pollutants, particularly airborne acidity, were associated with daily respiratory symptoms. PMID:1851397

  12. Asthmatic responses to airborne acid aerosols

    SciTech Connect

    Ostro, B.D.; Lipsett, M.J.; Wiener, M.B.; Selner, J.C. )

    1991-06-01

    Controlled exposure studies suggest that asthmatics may be more sensitive to the respiratory effects of acidic aerosols than individuals without asthma. This study investigates whether acidic aerosols and other air pollutants are associated with respiratory symptoms in free-living asthmatics. Daily concentrations of hydrogen ion (H+), nitric acid, fine particulates, sulfates and nitrates were obtained during an intensive air monitoring effort in Denver, Colorado, in the winter of 1987-88. A panel of 207 asthmatics recorded respiratory symptoms, frequency of medication use, and related information in daily diaries. We used a multiple regression time-series model to analyze which air pollutants, if any, were associated with health outcomes reported by study participants. Airborne H+ was found to be significantly associated with several indicators of asthma status, including moderate or severe cough and shortness of breath. Cough was also associated with fine particulates, and shortness of breath with sulfates. Incorporating the participants' time spent outside and exercise intensity into the daily measure of exposure strengthened the association between these pollutants and asthmatic symptoms. Nitric acid and nitrates were not significantly associated with any respiratory symptom analyzed. In this population of asthmatics, several outdoor air pollutants, particularly airborne acidity, were associated with daily respiratory symptoms.

  13. 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.

  14. Airborne fungi--a resurvey

    SciTech Connect

    Meyer, G.H.; Prince, H.E.; Raymer, W.J.

    1983-07-01

    A 15-month survey of airborne fungi at 14 geographical stations was conducted to determine the incidence of different fungal genera. Five of these stations were surveyed 25 years earlier. A comparison between previous studies and present surveys revealed similar organisms at each station with slight shifts in frequency of dominant genera.

  15. Tropospheric and Airborne Emission Spectrometers

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas; Beer, Reinhard

    1996-01-01

    X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

  16. AARD - Autonomous Airborne Refueling Demonstration

    NASA Technical Reports Server (NTRS)

    Ewers, Dick

    2007-01-01

    This viewgraph document reviews the Autonomous Airborne Refueling Demonstration program, and NASA Dryden's work in the program. The primary goal of the program is to make one fully automatic probe-to-drogue engagement using the AARD system. There are pictures of the aircraft approaching to the docking.

  17. Airborne particulate matter and spacecraft internal environments

    NASA Technical Reports Server (NTRS)

    Liu, Benjamin Y. H.; Rubow, Kenneth L.; Mcmurry, Peter H.; Kotz, Thomas J.; Russo, Dane

    1991-01-01

    Instrumentation, consisting of a Shuttle Particle Sampler (SPS) and a Shuttle Particle Monitor (SPM), has been developed to characterize the airborne particulate matter in the Space Shuttle cabin during orbital flight. The SPS size selectively collects particles in four size fractions (0-2.5, 2.5-10, 10-100, and greater than 100 microns) which are analyzed postflight for mass concentration and size distribution, elemental composition, and morphology. The SPM provides a continuous record of particle concentration through photometric light scattering. Measurements were performed onboard Columbia, OV-102, during the flight of STS-32 in January 1990. No significant changes were observed in the particle mass concentration, size distribution, or chemical composition in samples collected during flight-day 2 and flight-day 7. The total mass concentration was 56 microg/cu cm with approximately half of the particles larger than 100 microns. Elemental analysis showed that roughly 70 percent of the particles larger than 2.5 microns were carbonaceous with small amounts of other elements present. The SPM showed no temporal or spatial variation in particle mass concentration during the mission.

  18. Detecting Airborne Mercury by Use of Polymer/Carbon Films

    NASA Technical Reports Server (NTRS)

    Shevade, Abhijit; Ryan, Margaret; Homer, Margie; Kisor, Adam; Jewell, April; Yen, Shiao-Pin; Manatt, Kenneth; Blanco, Mario; Goddard, William

    2009-01-01

    Films made of certain polymer/carbon composites have been found to be potentially useful as sensing films for detecting airborne elemental mercury at concentrations on the order of tens of parts per billion or more. That is to say, when the polymer/carbon composite films are exposed to air containing mercury vapor, their electrical resistances decrease by measurable amounts. Because airborne mercury is a health hazard, it is desirable to detect it with great sensitivity, especially in enclosed environments in which there is a risk of a mercury leak from lamps or other equipment. The present effort to develop polymerbased mercury-vapor sensors complements the work reported in NASA Tech Briefs Detecting Airborne Mercury by Use of Palladium Chloride (NPO- 44955), Vol. 33, No. 7 (July 2009), page 48 and De tecting Airborne Mer cury by Use of Gold Nanowires (NPO-44787), Vol. 33, No. 7 (July 2009), page 49. Like those previously reported efforts, the present effort is motivated partly by a need to enable operation and/or regeneration of sensors under relatively mild conditions more specifically, at temperatures closer to room temperature than to the elevated temperatures (greater than 100 C ) needed for regeneration of sensors based on noble-metal films. The present polymer/carbon films are made from two polymers, denoted EYN1 and EYN2 (see Figure 1), both of which are derivatives of poly-4-vinyl pyridine with amine functional groups. Composites of these polymers with 10 to 15 weight percent of carbon were prepared and solution-deposited onto the JPL ElectronicNose sensor substrates for testing. Preliminary test results showed that the resulting sensor films gave measurable indications of airborne mercury at concentrations on the order of tens of parts per billion (ppb) or more. The operating temperature range for the sensing films was 28 to 40 C and that the sensor films regenerated spontaneously, without heating above operating temperature (see Figure 2).

  19. Determination of airborne nanoparticles from welding operations.

    PubMed

    Gomes, João Fernando Pereira; Albuquerque, Paula Cristina Silva; Miranda, Rosa Maria Mendes; Vieira, Maria Teresa Freire

    2012-01-01

    The aim of this study is to assess the levels of airborne ultrafine particles emitted in welding processes (tungsten inert gas [TIG], metal active gas [MAG] of carbon steel, and friction stir welding [FSW] of aluminum) in terms of deposited area in pulmonary alveolar tract using a nanoparticle surface area monitor (NSAM) analyzer. The obtained results showed the dependence of process parameters on emitted ultrafine particles and demonstrated the presence of ultrafine particles compared to background levels. Data indicated that the process that resulted in the lowest levels of alveolar deposited surface area (ADSA) was FSW, followed by TIG and MAG. However, all tested processes resulted in significant concentrations of ultrafine particles being deposited in humans lungs of exposed workers. PMID:22788362

  20. Lidar measurements of airborne particulate matter

    NASA Astrophysics Data System (ADS)

    Li, Guangkun; Philbrick, C. Russell

    2003-03-01

    Raman lidar techniques have been used in remote sensing to measure the aerosol optical extinction in the lower atmosphere, as well as water vapor, temperature and ozone profiles. Knowledge of aerosol optical properties assumes special importance in the wake of studies strongly correlating airborne particulate matter with adverse health effects. Optical extinction depends upon the concentration, composition, and size distribution of the particulate matter. Optical extinction from lidar returns provide information on particle size and density. The influence of relative humidity upon the growth and size of aerosols, particularly the sulfate aerosols along the northeast US region, has been investigated using a Raman lidar during several field measurement campaigns. A particle size distribution model is being developed and verified based on the experimental results. Optical extinction measurements from lidar in the NARSTO-NE-OPS program in Philadelphia PA, during summer of 1999 and 2001, have been analyzed and compared with other measurements such as PM sampling and particle size measurements.

  1. Wavelet-based fractal analysis of airborne pollen

    NASA Astrophysics Data System (ADS)

    Degaudenzi, M. E.; Arizmendi, C. M.

    1999-06-01

    The most abundant biological particles in the atmosphere are pollen grains and spores. Self-protection of a pollen allergy is possible through information about future pollen contents in the air. In spite of the importance of airborne pollen concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of daily pollen forecasts result in failures. Previous analyses of the dynamic characteristics of atmospheric pollen time series indicate that the system can be described by a low dimensional chaotic map. We apply a wavelet transform to study the multifractal characteristics of an airborne pollen time series. The information and the correlation dimensions correspond to a chaotic system showing a loss of information with time evolution.

  2. Characterisation of particulate matter on airborne pollen grains.

    PubMed

    Ribeiro, Helena; Guimarães, Fernanda; Duque, Laura; Noronha, Fernando; Abreu, Ilda

    2015-11-01

    A characterization of the physical-chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles' equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical-chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity. PMID:26141127

  3. Satellite and airborne IR sensor validation by an airborne interferometer

    SciTech Connect

    Gumley, L.E.; Delst, P.F. van; Moeller, C.C.

    1996-11-01

    The validation of in-orbit longwave IR radiances from the GOES-8 Sounder and inflight longwave IR radiances from the MODIS Airborne Simulator (MAS) is described. The reference used is the airborne University of Wisconsin High Resolution Interferometer Sounder (HIS). The calibration of each sensor is described. Data collected during the Ocean Temperature Interferometric Survey (OTIS) experiment in January 1995 is used in the comparison between sensors. Detailed forward calculations of at-sensor radiance are used to account for the difference in GOES-8 and HIS altitude and viewing geometry. MAS radiances and spectrally averaged HIS radiances are compared directly. Differences between GOES-8 and HIS brightness temperatures, and GOES-8 and MAS brightness temperatures, are found to be with 1.0 K for the majority of longwave channels examined. The same validation approach will be used for future sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS). 11 refs., 2 figs., 4 tabs.

  4. Identifying Airborne Pathogens in Time to Respond

    SciTech Connect

    Hazi, A

    2006-01-25

    Among the possible terrorist activities that might threaten national security is the release of an airborne pathogen such as anthrax. Because the potential damage to human health could be severe, experts consider 1 minute to be an operationally useful time limit for identifying the pathogen and taking action. Many commercial systems can identify airborne pathogenic microbes, but they take days or, at best, hours to produce results. The Department of Homeland Security (DHS) and other U.S. government agencies are interested in finding a faster approach. To answer this national need, a Livermore team, led by scientist Eric Gard, has developed the bioaerosol mass spectrometry (BAMS) system--the only instrument that can detect and identify spores at low concentrations in less than 1 minute. BAMS can successfully distinguish between two related but different spore species. It can also sort out a single spore from thousands of other particles--biological and nonbiological--with no false positives. The BAMS team won a 2005 R&D 100 Award for developing the system. Livermore's Laboratory Directed Research and Development (LDRD) Program funded the biomedical aspects of the BAMS project, and the Department of Defense's Technical Support Working Group and Defense Advanced Research Project Agency funded the biodefense efforts. Developing a detection system that can analyze small samples so quickly has been challenging. Livermore engineer Vincent Riot, who worked on the BAMS project, explains, ''A typical spore weighs approximately one-trillionth of a gram and is dispersed in the atmosphere, which contains naturally occurring particles that could be present at concentrations thousands of times higher. Previous systems also had difficulty separating benign organisms from those that are pathogenic but very similar, which has resulted in false alarms''.

  5. Compounds in airborne particulates - Salts and hydrocarbons. [at Cleveland, OH

    NASA Technical Reports Server (NTRS)

    King, R. B.; Antoine, A. C.; Fordyce, J. S.; Neustadter, H. E.; Leibecki, H. F.

    1977-01-01

    Concentrations of 10 polycyclic aromatic hydrocarbons (PAH), the aliphatics as a group, sulfate, nitrate, fluoride, acidity, and carbon in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1-year period during 1971 and 1972. Analytical methods used included gas chromatography, colorimetry, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, and the analytical methods are evaluated. The data are discussed relative to other studies and source origins. High concentrations downwind of coke ovens for 3,4 benzopyrene are discussed. Hydrocarbon correlation studies indicated no significant relations among compounds studied.

  6. AIRBORNE RADIATION DETECTOR

    DOEpatents

    Cartmell, T.R.; Gifford, J.F.

    1959-08-01

    An ionization chamber used for measuring the radioactivity of dust present in atmospheric air is described. More particularly. the patent describes a device comprising two concentric open ended, electrically connected cylinders between which is disposed a wire electrcde. A heating source is disposed inside of the cylinder to circulate air through the space between the two cylinders by convective flow. A high voltage electric field between the wire electrcde of the electrically connected cylinder will cause ionization of the air as it passes therethrough.

  7. Detecting Airborne Mercury by Use of Palladium Chloride

    NASA Technical Reports Server (NTRS)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Jewell, April; Manatt, Kenneth; Torres, Julia; Soler, Jessica; Taylor, Charles

    2009-01-01

    Palladium chloride films have been found to be useful as alternatives to the gold films heretofore used to detect airborne elemental mercury at concentrations of the order of parts per billion (ppb). Somewhat more specifically, when suitably prepared palladium chloride films are exposed to parts-per-billion or larger concentrations of airborne mercury, their electrical resistances change by amounts large enough to be easily measurable. Because airborne mercury adversely affects health, it is desirable to be able to detect it with high sensitivity, especially in enclosed environments in which there is a risk of leakage of mercury from lamps or other equipment. The detection of mercury by use of gold films involves the formation of gold/mercury amalgam. Gold films offer adequate sensitivity for detection of airborne mercury and could easily be integrated into an electronic-nose system designed to operate in the temperature range of 23 to 28 C. Unfortunately, in order to regenerate a gold-film mercury sensor, one must heat it to a temperature of 200 C for several minutes in clean flowing air. In preparation for an experiment to demonstrate the present sensor concept, palladium chloride was deposited from an aqueous solution onto sets of gold electrodes and sintered in air to form a film. Then while using the gold electrodes to measure the electrical resistance of the films, the films were exposed, at a temperature of 25 C, to humidified air containing mercury at various concentrations from 0 to 35 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury in room-temperature air at concentrations of at least 2.5 ppb and can readily be regenerated at temperatures <40 C.

  8. Dual channel airborne hygrometer for climate research

    NASA Astrophysics Data System (ADS)

    Tatrai, David; Gulyas, Gabor; Bozoki, Zoltan; Szabo, Gabor

    2015-04-01

    Airborne hygrometry has an increasing role in climate research and nowadays the determination of cloud content especially of cirrus clouds is gaining high interest. The greatest challenges for such measurements are being used from ground level up to the lower stratosphere with appropriate precision and accuracy the low concentration and varying environment pressure. Such purpose instrument was probably presented first by our research group [1-2]. The development of the system called WaSUL-Hygro and some measurement results will be introduced. The measurement system is based on photoacoustic spectroscopy and contains two measuring cells, one is used to measure water vapor concentration which is typically sampled by a sideward or backward inlet, while the second one measures total water content (water vapor plus ice crystals) after evaporation in a forward facing sampler. The two measuring cells are simultaneously illuminated through with one distributed feedback diode laser (1371 or 1392 nm). Two early versions have been used within the CARIBIC project. During the recent years, efforts were made to turn the system into a more reliable and robust one [3]. The first important development was the improvement of the wavelength stabilization method of the applied laser. As a result the uncertainty of the wavelength is less than 40fm, which corresponds to less than 0.05% of PA signal uncertainty. This PA signal uncertainty is lower than the noise level of the system itself. The other main development was the improvement of the concentration determination algorithm. For this purpose several calibration and data evaluation methods were developed, the combination of the latest ones have made the system traceable to the humidity generator applied during the calibration within 1.5% relative deviation or within noise level, whichever is greater. The improved system was several times blind tested at the Environmental Simulation Facility (Forschungszentrum Jülich, Germany) in

  9. Large aperture scanning airborne lidar

    NASA Technical Reports Server (NTRS)

    Smith, J.; Bindschadler, R.; Boers, R.; Bufton, J. L.; Clem, D.; Garvin, J.; Melfi, S. H.

    1988-01-01

    A large aperture scanning airborne lidar facility is being developed to provide important new capabilities for airborne lidar sensor systems. The proposed scanning mechanism allows for a large aperture telescope (25 in. diameter) in front of an elliptical flat (25 x 36 in.) turning mirror positioned at a 45 degree angle with respect to the telescope optical axis. The lidar scanning capability will provide opportunities for acquiring new data sets for atmospheric, earth resources, and oceans communities. This completed facility will also make available the opportunity to acquire simulated EOS lidar data on a near global basis. The design and construction of this unique scanning mechanism presents exciting technological challenges of maintaining the turning mirror optical flatness during scanning while exposed to extreme temperatures, ambient pressures, aircraft vibrations, etc.

  10. Quantification of the pathological response and fate in the lung and pleura of chrysotile in combination with fine particles compared to amosite-asbestos following short-term inhalation exposure

    PubMed Central

    Bernstein, DM; Rogers, RA; Sepulveda, R; Donaldson, K; Schuler, D; Gaering, S; Kunzendorf, P; Chevalier, J; Holm, SE

    2011-01-01

    The marked difference in biopersistence and pathological response between chrysotile and amphibole asbestos has been well documented. This study is unique in that it has examined a commercial chrysotile product that was used as a joint compound. The pathological response was quantified in the lung and translocation of fibers to and pathological response in the pleural cavity determined. This paper presents the final results from the study. Rats were exposed by inhalation 6 h/day for 5 days to a well-defined fiber aerosol. Subgroups were examined through 1 year. The translocation to and pathological response in the pleura was examined by scanning electron microscopy and confocal microscopy (CM) using noninvasive methods.The number and size of fibers was quantified using transmission electron microscopy and CM. This is the first study to use such techniques to characterize fiber translocation to and the response of the pleural cavity. Amosite fibers were found to remain partly or fully imbedded in the interstitial space through 1 year and quickly produced granulomas (0 days) and interstitial fibrosis (28 days). Amosite fibers were observed penetrating the visceral pleural wall and were found on the parietal pleural within 7 days postexposure with a concomitant inflammatory response seen by 14 days. Pleural fibrin deposition, fibrosis, and adhesions were observed, similar to that reported in humans in response to amphibole asbestos. No cellular or inflammatory response was observed in the lung or the pleural cavity in response to the chrysotile and sanded particles (CSP) exposure. These results provide confirmation of the important differences between CSP and amphibole asbestos. PMID:21639706

  11. Exposure assessment to airborne endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide in open style swine houses.

    PubMed

    Chang, C W; Chung, H; Huang, C F; Su, H J

    2001-08-01

    Information is limited for the exposure levels of airborne hazardous substances in swine feed buildings that are not completely enclosed. Open-style breeding, growing and finishing swine houses in six farms in subtropical Taiwan were studied for the airborne concentrations of endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide. The air in the farrowing and nursery stalls as partially enclosed was also simultaneously evaluated. Three selected gases and airborne dusts were quantified respectively by using Drager diffusion tubes and a filter-weighing method. Endotoxin was analyzed by the Limulus amoebocyte lysate assay. Average concentration of airborne total endotoxin among piggeries was between 36.8 and 298 EU/m(3), while that for respirable endotoxin was 14.1-129 EU/m(3). Mean concentration of total dust was between 0.15 and 0.34 mg/m(3), with average level of respirable dust of 0.14 mg/m(3). The respective concentrations of NH3, CO2 and H2S were less than 5 ppm, 600-895 ppm and less than 0.2 ppm. Airborne concentrations of total dust and endotoxin in the nursery house were higher than in the other types of swine houses. The finishing house presented the highest exposure risk to NH3, CO2 and H2S. Employees working in the finishing stalls were also exposed to the highest airborne levels of respirable endotoxin and dust. On the other hand, the air of the breeding units was the least contaminated in terms of airborne endotoxin, dust, NH3, CO2 and H2S. The airborne concentrations of substances measured in the present study were all lower than most of published studies conducted in mainly enclosed swine buildings. Distinct characteristics, including maintaining swine houses in an open status and frequent spraying water inside the stalls, significantly reduce accumulation of gases and airborne particulates. PMID:11513795

  12. Magnetic airborne survey - geophysical flight

    NASA Astrophysics Data System (ADS)

    de Barros Camara, Erick; Nei Pereira Guimarães, Suze

    2016-06-01

    This paper provides a technical review process in the area of airborne acquisition of geophysical data, with emphasis for magnetometry. In summary, it addresses the calibration processes of geophysical equipment as well as the aircraft to minimize possible errors in measurements. The corrections used in data processing and filtering are demonstrated with the same results as well as the evolution of these techniques in Brazil and worldwide.

  13. Airborne microorganisms from waste containers.

    PubMed

    Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

    2012-01-01

    In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste. PMID:23047084

  14. Airborne lidar global positioning investigations

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.

    1988-01-01

    The Global Positioning System (GPS) network of satellites shows high promise of revolutionizing methods for conducting surveying, navigation, and positioning. This is especially true in the case of airborne or satellite positioning. A single GPS receiver (suitably adapted for aircraft deployment) can yield positioning accuracies (world-wide) in the order of 30 to 50 m vertically, as well as horizontally. This accuracy is dramatically improved when a second GPS receiver is positioned at a known horizontal and vertical reference. Absolute horizontal and vertical positioning of 1 to 2 m are easily achieved over areas of separation of tens of km. If four common satellites remain in lock in both receivers, then differential phase pseudo-ranges on the GPS L-band carrier can be utilized to achieve accuracies of + or - 10 cm and perhaps as good as + or - 2 cm. The initial proof of concept investigation for airborne positioning using the phase difference between the airborne and stationary GPS receivers was conducted and is examined.

  15. 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.

  16. USE OF WATER RAMAN EMISSION TO CORRECT AIRBORNE LASER FLUOROSENSOR DATA FOR EFFECTS OF WATER OPTICAL ATTENUATION

    EPA Science Inventory

    Airborne laser fluorosensor measurements of fluorophore concentrations in surface waters are highly sensitive to interference from changes in optical attenuation. This interference can be eliminated by normalizing the fluorescence signal with the concurrent water Raman signal. In...

  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. Effect of land uses and wind direction on the contribution of local sources to airborne pollen.

    PubMed

    Rojo, Jesús; Rapp, Ana; Lara, Beatriz; Fernández-González, Federico; Pérez-Badia, Rosa

    2015-12-15

    The interpretation of airborne pollen levels in cities based on the contribution of the surrounding flora and vegetation is a useful tool to estimate airborne allergen concentrations and, consequently, to determine the allergy risk for local residents. This study examined the pollen spectrum in a city in central Spain (Guadalajara) and analysed the vegetation landscape and land uses within a radius of 20km in an attempt to identify and locate the origin of airborne pollen and to determine the effect of meteorological variables on pollen emission and dispersal. The results showed that local wind direction was largely responsible for changes in the concentrations of different airborne pollen types. The land uses contributing most to airborne pollen counts were urban green spaces, though only 0.1% of the total surface area studied, and broadleaved forest which covered 5% of the study area. These two types of land use together accounted for 70% of the airborne pollen. Crops, scrubland and pastureland, though covering 80% of the total surface area, contributed only 18.6% to the total pollen count, and this contribution mainly consisted of pollen from Olea and herbaceous plants, including Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Pollen from ornamental species were mainly associated with easterly (Platanus), southerly (Cupressaceae) and westerly (Cupressaceae and Platanus) winds from the areas where the city's largest parks and gardens are located. Quercus pollen was mostly transported by winds blowing in from holm-oak stands on the eastern edge of the city. The highest Populus pollen counts were associated with easterly and westerly winds blowing in from areas containing rivers and streams. The airborne pollen counts generally rose with increasing temperature, solar radiation and hours of sunlight, all of which favour pollen release. In contrast, pollen counts declined with increased relative humidity and rainfall, which hinder airborne pollen transport

  19. The use of airborne lasers in terrestrial and water environments

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Link, L. E.; Swift, R. N.

    1983-01-01

    This document has the objective to provide some information regarding the applications for which an airborne laser system can be utilized. The considered data have been collected with the NASA Airborne Oceanographic Lidar (AOL), operational since 1977 as a flying laser laboratory. The most basic mode of operation of the AOL involves operation as a profiler. The data collected are similar to those which would be collected by a ground survey party. In the fluorosensing mode, pulsed laser light is used to induce fluorescence in various pigments contained in land and water targets. A capability for reliably mapping bottom geometry in clear ocean water to depths of 10-12 meters was also demonstrated, while other studies are related to the utilization of the AOL for synoptic mapping of surface layer concentrations of chlorophyll and other photopigments contained in phytoplankton.

  20. Active-passive airborne ocean color measurement. II - Applications

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.; Yungel, J. K.

    1986-01-01

    Reported here for the first time is the use of a single airborne instrument to make concurrent measurements of oceanic chlorophyll concentration by (1) laser-induced fluorescence, (2) passive upwelling radiance, and (3) solar-induced chlorophyll fluorescence. Results from field experiments conducted with the NASA airborne oceanographic lidar (AOL) in the New York Bight demonstrate the capability of a single active-passive instrument to perform new and potentially important ocean color studies related to (1) active lidar validation of passive ocean color in-water algorithms, (2) chlorophyll a in vivo fluorescence yield variability, (3) calibration of active multichannel lidar systems, (4) effect of sea state on passive and active ocean color measurements, (5) laser/solar-induced chlorophyll fluorescence investigations, and (6) subsequent improvement of satellite-borne ocean color scanners. For validation and comparison purposes a separate passive ocean color sensor was also flown along with the new active-passive sensor during these initial field trials.

  1. Off-axis measurements of atmospheric trace gases by use of an airborne ultraviolet-visible spectrometer.

    PubMed

    Petritoli, Andrea; Ravegnani, Fabrizio; Giovanelli, Giorgio; Bortoli, Daniele; Bonafè, Ubaldo; Kostadinov, Ivan; Oulanovsky, Alexey

    2002-09-20

    An airborne UV-visible spectrometer, the Gas Analyzer Spectrometer Correlating Optical Differences, airborne version (GASCOD/A4pi) was successfully operated during the Airborne Polar Experiment, Geophysica Aircraft in Antarctica airborne campaign from Ushuaia (54 degrees 49' S, 68 degrees 18' W), Argentina in southern spring 1999. The instrument measured scattered solar radiation through three optical windows with a narrow field of view (FOV), one from the zenith, two from the horizontal, as well as actinic fluxes through 2pi FOV radiometric heads. Only a few airborne measurements of scattered solar radiation at different angles from the zenith are available in the literature. With our configuration we attempted to obtain the average line-of-sight concentrations of detectable trace gases. The retrieval method, based on differential optical absorption spectroscopy, is described and results for ozone are shown and compared with measurements from an in situ instrument as the first method of validation. PMID:12269557

  2. Off-axis measurements of atmospheric trace gases by use of an airborne ultraviolet-visible spectrometer

    NASA Astrophysics Data System (ADS)

    Petritoli, Andrea; Ravegnani, Fabrizio; Giovanelli, Giorgio; Bortoli, Daniele; Bonafè, Ubaldo; Kostadinov, Ivan; Oulanovsky, Alexey

    2002-09-01

    An airborne UV-visible spectrometer, the Gas Analyzer Spectrometer Correlating Optical Differences, airborne version (GASCOD/A4π) was successfully operated during the Airborne Polar Experiment, Geophysica Aircraft in Antarctica airborne campaign from Ushuaia (54°49'S, 68°18'W), Argentina in southern spring 1999. The instrument measured scattered solar radiation through three optical windows with a narrow field of view (FOV), one from the zenith, two from the horizontal, as well as actinic fluxes through 2π FOV radiometric heads. Only a few airborne measurements of scattered solar radiation at different angles from the zenith are available in the literature. With our configuration we attempted to obtain the average line-of-sight concentrations of detectable trace gases. The retrieval method, based on differential optical absorption spectroscopy, is described and results for ozone are shown and compared with measurements from an in situ instrument as the first method of validation.

  3. Prospecting by sampling and analysis of airborne particulates and gases

    DOEpatents

    Sehmel, G.A.

    1984-05-01

    A method is claimed for prospecting by sampling airborne particulates or gases at a ground position and recording wind direction values at the time of sampling. The samples are subsequently analyzed to determine the concentrations of a desired material or the ratios of the desired material to other identifiable materials in the collected samples. By comparing the measured concentrations or ratios to expected background data in the vicinity sampled, one can select recorded wind directions indicative of the upwind position of the land-based source of the desired material.

  4. Airborne measurements of cloud forming nuclei and aerosol particles at Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    Radke, L. F.; Langer, G.; Hindman, E. E., II

    1978-01-01

    Results of airborne measurements of the sizes and concentrations of aerosol particles, ice nuclei, and cloud condensation nuclei that were taken at Kennedy Space Center, Florida, are presented along with a detailed description of the instrumentation and measuring capabilities of the University of Washington airborne measuring facility (Douglas B-23). Airborne measurements made at Ft. Collins, Colorado, and Little Rock, Arkansas, during the ferry of the B-23 are presented. The particle concentrations differed significantly between the clean air over Ft. Collins and the hazy air over Little Rock and Kennedy Space Center. The concentrations of cloud condensation nuclei over Kennedy Space Center were typical of polluted eastern seaboard air. Three different instruments were used to measure ice nuclei: one used filters to collect the particles, and the others used optical and acoustical methods to detect ice crystals grown in portable cloud chambers. A comparison of the ice nucleus counts, which are in good agreement, is presented.

  5. An Overview of the Challenges with and Proposed Solutions for the Ingest and Distribution Processes For Airborne Data Management

    NASA Astrophysics Data System (ADS)

    Northup, E. A.; Beach, A. L., III; Early, A. B.; Kusterer, J.; Quam, B.; Wang, D.; Chen, G.

    2015-12-01

    The current data management practices for NASA airborne field projects have successfully served science team data needs over the past 30 years to achieve project science objectives, however, users have discovered a number of issues in terms of data reporting and format. The ICARTT format, a NASA standard since 2010, is currently the most popular among the airborne measurement community. Although easy for humans to use, the format standard is not sufficiently rigorous to be machine-readable, and there lacks a standard variable naming convention among the many airborne measurement variables. This makes data use and management tedious and resource intensive, and also create problems in Distributed Active Archive Center (DAAC) data ingest procedures and distribution. Further, most DAACs use metadata models that concentrate on satellite data observations, making them less prepared to deal with airborne data. There also exists a substantial amount of airborne data distributed by websites designed for science team use that are less friendly to users unfamiliar with operations of airborne field studies. A number of efforts are underway to help overcome the issues with airborne data discovery and distribution. The ICARTT Refresh Earth Science Data Systems Working Group (ESDSWG) was established to enable a platform for atmospheric science data providers, users, and data managers to collaborate on developing new criteria for the file format in an effort to enhance airborne data usability. In addition, the NASA Langley Research Center Atmospheric Science Data Center (ASDC) has developed the Toolsets for Airborne Data (TAD) to provide web-based tools and centralized access to airborne in situ measurements of atmospheric composition. This presentation will discuss the aforementioned challenges and attempted solutions in an effort to demonstrate how airborne data management can be improved to streamline data ingest and discoverability to a broader user community.

  6. A Comparison between Airborne and Mountaintop Cloud Microphysics

    NASA Astrophysics Data System (ADS)

    David, R.; Lowenthal, D. H.; Hallar, A. G.; McCubbin, I.; Avallone, L. M.; Mace, G. G.; Wang, Z.

    2014-12-01

    Complex terrain has a large impact on cloud dynamics and microphysics. Several studies have examined the microphysical details of orographically-enhanced clouds from either an aircraft or from a mountain top location. However, further research is needed to characterize the relationships between mountain top and airborne microphysical properties. During the winter of 2011, an airborne study, the Colorado Airborne Mixed-Phase Cloud Study (CAMPS), and a ground-based field campaign, the Storm Peak Lab (SPL) Cloud Property Validation Experiment (StormVEx) were conducted in the Park Range of the Colorado Rockies. The CAMPS study utilized the University of Wyoming King Air (UWKA) to provide airborne cloud microphysical and meteorological data on 29 flights totaling 98 flight hours over the Park Range from December 15, 2010 to February 28, 2011. The UWKA was equipped with instruments that measured both cloud droplet and ice crystal size distributions, liquid water content, total water content (vapor, liquid, and ice), and 3-dimensional wind speed and direction. The Wyoming Cloud Radar and Lidar were also deployed during the campaign. These measurements are used to characterize cloud structure upwind and above the Park Range. StormVEx measured cloud droplet, ice crystal, and aerosol size distributions at SPL, located on the west summit of Mt. Werner at 3220m MSL. The observations from SPL are used to determine mountain top cloud microphysical properties at elevations lower than the UWKA was able to sample in-situ. Comparisons showed that cloud microphysics aloft and at the surface were consistent with respect to snow growth processes while small crystal concentrations were routinely higher at the surface, suggesting ice nucleation near cloud base. The effects of aerosol concentrations and upwind stability on mountain top and downwind microphysics are considered.

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

    PubMed

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

    2015-07-01

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

  8. Evaluation of Airborne Particle Emissions from Commercial Products Containing Carbon Nanotubes

    PubMed Central

    Huang, Guannan; Park, Jae Hong; Cena, Lorenzo G.; Shelton, Betsy L.; Peters, Thomas M.

    2012-01-01

    The emission of the airborne particles from epoxy resin test sticks with different CNT loadings and two commercial products were characterized while sanding with three grit sizes and three disc sander speeds. The total number concentrations, respirable mass concentrations, and particle size number/mass distributions of the emitted particles were measured using a condensation particle counter, an optical particle counter, and a scanning mobility particle sizer. The emitted particles were sampled on a polycarbonate filter and analyzed using electron microscopy. The highest number concentrations (arithmetic mean = 4670 particles/cm3) were produced with coarse sandpaper, 2% (by weight) CNT test sticks and medium disc sander speed, whereas the lowest number concentrations (arithmetic mean = 92 particles/cm3) were produced with medium sandpaper, 2% CNT test sticks and slow disc sander speed. Respirable mass concentrations were highest (arithmetic mean = 1.01 mg/m3) for fine sandpaper, 2% CNT test sticks and medium disc sander speed and lowest (arithmetic mean = 0.20 mg/m3) for medium sandpaper, 0% CNT test sticks and medium disc sander speed. For CNT-epoxy samples, airborne particles were primarily micrometer-sized epoxy cores with CNT protrusions. No free CNTs were observed in airborne samples, except for tests conducted with 4% CNT epoxy. The number concentration, mass concentration, and size distribution of airborne particles generated when products containing CNTs are sanded depends on the conditions of sanding and the characteristics of the material being sanded. PMID:23204914

  9. Geophex airborne unmanned survey system

    SciTech Connect

    Won, I.J.; Taylor, D.W.A.

    1995-03-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

  10. Airborne wavemeter validation and calibration

    NASA Technical Reports Server (NTRS)

    Goad, Joseph H., Jr.; Rinsland, Pamela L.; Kist, Edward H., Jr.; Geier, Erika B.; Banziger, Curtis G.

    1992-01-01

    This manuscript outlines a continuing effort to validate and verify the performance of an airborne autonomous wavemeter for tuning solid state lasers to a desired wavelength. The application is measuring the vertical profiles of atmospheric water vapor using a differential absorption lidar (DIAL) technique. Improved wavemeter performance data for varying ambient temperatures are presented. This resulted when the electronic grounding and shielding were improved. The results with short pulse duration lasers are also included. These lasers show that similar performance could be obtained with lasers operating in the continuous and the pulsed domains.

  11. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.J.; Keiswetter, D.

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  12. 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.

  13. Biological monitoring of airborne pollution

    SciTech Connect

    Ditz, D.W. )

    1990-01-01

    Common plants such as grasses, mosses, and even goldenrod may turn out to have a new high-tech role as monitors of airborne pollution from solid waste incinerators. Certain plants that respond to specific pollutants can provide continuous surveillance of air quality over long periods of time: they are bio-indicators. Other species accumulate pollutants and can serve as sensitive indicators of pollutants and of food-chain contamination: they are bio-accumulators. Through creative use of these properties, biological monitoring can provide information that cannot be obtained by current methods such as stack testing.

  14. Airborne Research Experience for Educators

    NASA Astrophysics Data System (ADS)

    Costa, V. B.; Albertson, R.; Smith, S.; Stockman, S. A.

    2009-12-01

    The Airborne Research Experience for Educators (AREE) Program, conducted by the NASA Dryden Flight Research Center Office of Education in partnership with the AERO Institute, NASA Teaching From Space Program, and California State University Fullerton, is a complete end-to-end residential research experience in airborne remote sensing and atmospheric science. The 2009 program engaged ten secondary educators who specialize in science, technology, engineering or mathematics in a 6-week Student Airborne Research Program (SARP) offered through NSERC. Educators participated in collection of in-flight remote sensor data during flights aboard the NASA DC-8 as well as in-situ research on atmospheric chemistry (bovine emissions of methane); algal blooms (remote sensing to determine location and degree of blooms for further in-situ analysis); and crop classification (exploration of how drought conditions in Central California have impacted almond and cotton crops). AREE represents a unique model of the STEM teacher-as-researcher professional development experience because it asks educators to participate in a research experience and then translate their experiences into classroom practice through the design, implementation, and evaluation of instructional materials that emphasize the scientific research process, inquiry-based investigations, and manipulation of real data. Each AREE Master Educator drafted a Curriculum Brief, Teachers Guide, and accompanying resources for a topic in their teaching assignment Currently, most professional development programs offer either a research experience OR a curriculum development experience. The dual nature of the AREE model engaged educators in both experiences. Educators’ content and pedagogical knowledge of STEM was increased through the review of pertinent research articles during the first week, attendance at lectures and workshops during the second week, and participation in the airborne and in-situ research studies, data

  15. Airborne Visible Laser Optical Communications Program (AVLOC)

    NASA Technical Reports Server (NTRS)

    Ward, J. H.

    1975-01-01

    The design, development, and operation of airborne and ground-based laser communications and laser radar hardware is described in support of the Airborne Visible Laser Optical Communication program. The major emphasis is placed on the development of a highly flexible test bed for the evaluation of laser communications systems techniques and components in an operational environment.

  16. Global Test Range: Toward Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Mace, Thomas H.; Freudinger, Larry; DelFrate John H.

    2008-01-01

    This viewgraph presentation reviews the planned global sensor network that will monitor the Earth's climate, and resources using airborne sensor systems. The vision is an intelligent, affordable Earth Observation System. Global Test Range is a lab developing trustworthy services for airborne instruments - a specialized Internet Service Provider. There is discussion of several current and planned missions.

  17. Airborne Relay-Based Regional Positioning System

    PubMed Central

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-01-01

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations. PMID:26029953

  18. The Continuous wavelet in airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Liang, X.; Liu, L.

    2013-12-01

    Airborne gravimetry is an efficient method to recover medium and high frequency band of earth gravity over any region, especially inaccessible areas, which can measure gravity data with high accuracy,high resolution and broad range in a rapidly and economical way, and It will play an important role for geoid and geophysical exploration. Filtering methods for reducing high-frequency errors is critical to the success of airborne gravimetry due to Aircraft acceleration determination based on GPS.Tradiontal filters used in airborne gravimetry are FIR,IIR filer and so on. This study recommends an improved continuous wavelet to process airborne gravity data. Here we focus on how to construct the continuous wavelet filters and show their working principle. Particularly the technical parameters (window width parameter and scale parameter) of the filters are tested. Then the raw airborne gravity data from the first Chinese airborne gravimetry campaign are filtered using FIR-low pass filter and continuous wavelet filters to remove the noise. The comparison to reference data is performed to determinate external accuracy, which shows that continuous wavelet filters applied to airborne gravity in this thesis have good performances. The advantages of the continuous wavelet filters over digital filters are also introduced. The effectiveness of the continuous wavelet filters for airborne gravimetry is demonstrated through real data computation.

  19. 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…

  20. Airborne Oceanographic Lidar (AOL) (Global Carbon Cycle)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This bimonthly contractor progress report covers the operation, maintenance and data management of the Airborne Oceanographic Lidar and the Airborne Topographic Mapper. Monthly activities included: mission planning, sensor operation and calibration, data processing, data analysis, network development and maintenance and instrument maintenance engineering and fabrication.

  1. Meeting Review: Airborne Aerosol Inlet Workshop

    NASA Technical Reports Server (NTRS)

    Baumgardner, Darrel; Huebert, Barry; Wilson, Chuck

    1991-01-01

    Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

  2. Presence of airborne fibers in tungsten refining and manufacturing processes: preliminary characterization.

    PubMed

    McKernan, John L; Toraason, Mark A; Fernback, Joseph E

    2008-07-01

    In tungsten refining and manufacturing processes, a series of tungsten oxides (WO(X)) are typically formed as intermediates in the production of tungsten powder. Studies in the Swedish tungsten refining and manufacturing industry have shown that intermediate tungsten refining processes can create WO(X) fibers. The purpose of the present study was to identify and provide a preliminary characterization of airborne tungsten-containing fiber dimensions, elemental composition, and concentrations in the U.S. tungsten refining and manufacturing industry. To provide the preliminary characterization, 10 static air samples were collected during the course of normal employee work activities and analyzed using standard fiber sampling and counting methods. Results from transmission electron microscopy analyses conducted indicate that airborne fibers with length > 0.5 microm, diameter > 0.01 microm, and aspect ratio > or = 3:1, with a geometric mean (GM) length of approximately 2.0 microm and GM diameter of approximately 0.25 microm, were present on 9 of the 10 air samples collected. Energy dispersive X-ray spectrometry results indicate that airborne fibers prior to the carburization process consisted primarily of tungsten and oxygen, with other elements being detected in trace quantities. Results from an air sample collected at the carburization process indicated the presence of fibers composed primarily of tungsten with oxygen and carbon, and traces of other elements. Based on National Institute for Occupational Safety and Health standard fiber counting rules, airborne fiber concentrations ranged from below the limit of detection to 0.14 f/cm(3). The calcining process was associated with the highest airborne fiber concentrations. More than 99% (574/578) of the airborne fibers identified had an aerodynamic diameter

  3. Domestic Mite Antigens in Floor and Airborne Dust at Workplaces in Comparison to Living Areas: A New Immunoassay to Assess Personal Airborne Allergen Exposure

    PubMed Central

    Sander, Ingrid; Zahradnik, Eva; Kraus, Gerhard; Mayer, Stefan; Neumann, Heinz-Dieter; Fleischer, Christina; Brüning, Thomas; Raulf-Heimsoth, Monika

    2012-01-01

    Objectives Allergens produced by domestic mites (DM) are among the most common allergic sensitizers and risk factors for asthma. To compare exposure levels between workplaces and living areas a new assay able to measure airborne DM antigen concentrations was developed. Methods At workplaces and in living areas, 213 floor dust samples and 92 personal inhalable dust samples were collected. For sensitive quantification of DM antigens, a new enzyme immunoassay (EIA) based on polyclonal antibodies to Dermatophagoides farinae extract was developed. Reactivity of five house dust mite and four storage mite species was tested. All dust samples were tested with the new EIA and with the Der f 1 and Der p 1-EIAs (Indoor Biotechnologies, UK) which detect major allergens from D. farinae and D. pteronyssinus by monoclonal antibodies. Samples below the detection limit in the DM-EIA were retested in an assay variant with a fluorogenic substrate (DM-FEIA). Results The newly developed DM-EIA detects antigens from all nine tested domestic mite species. It has a lower detection limit of 200 pg/ml of D.farinae protein, compared to 50 pg/ml for the DM-FEIA. DM antigens were detected by DM-EIA/FEIA in all floor dust and 80 (87%) of airborne samples. Der f 1 was found in 133 (62%) floor dust and in only 6 airborne samples, Der p 1 was found in 70 (33%) of floor samples and in one airborne sample. Der f 1 and DM concentrations were highly correlated. DM-antigens were significantly higher in inhalable airborne samples from textile recycling, bed feather filling, feed production, grain storage and cattle stables in comparison to living areas. Conclusions A new sensitive EIA directed at DM antigens was developed. DM antigen quantities were well correlated to Der f 1 values and were measurable in the majority (87%) of airborne dust samples. Some workplaces had significantly higher DM antigen concentrations than living areas. PMID:23285240

  4. A theoretical model for airborne radars

    NASA Astrophysics Data System (ADS)

    Faubert, D.

    1989-11-01

    This work describes a general theory for the simulation of airborne (or spaceborne) radars. It can simulate many types of systems including Airborne Intercept and Airborne Early Warning radars, airborne missile approach warning systems etc. It computes the average Signal-to-Noise ratio at the output of the signal processor. In this manner, one obtains the average performance of the radar without having to use Monte Carlo techniques. The model has provision for a waveform without frequency modulation and one with linear frequency modulation. The waveform may also have frequency hopping for Electronic Counter Measures or for clutter suppression. The model can accommodate any type of encounter including air-to-air, air-to-ground (look-down) and rear attacks. It can simulate systems with multiple phase centers on receive for studying advanced clutter or jamming interference suppression techniques. An Airborne Intercept radar is investigated to demonstrate the validity and the capability of the model.

  5. Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Liu, Li; Solmon, Fabien; Viovy, Nicolas; Khvorostyanov, Dmitry; Essl, Franz; Chuine, Isabelle; Colette, Augustin; Semenov, Mikhail A.; Schaffhauser, Alice; Storkey, Jonathan; Thibaudon, Michel; Epstein, Michelle M.

    2015-08-01

    Common ragweed (Ambrosia artemisiifolia) is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals. Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios. We estimate that by 2050 airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change. The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy.

  6. 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

  7. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.L.; Keiswetter, D.

    1995-12-31

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

  8. Technology for the detection of airborne intruders approaching the high-security high-value asset

    NASA Astrophysics Data System (ADS)

    Greneker, Eugene F., III

    1995-05-01

    Security plans to protect high-value assets usually concentrate on stopping potential ground intruders before they reach the asset. Barriers, such as fences, are the first line of defense against the found intruder, providing a delay mechanism. The sight of 10 to 12 foot high fencing topped with razor wire, guard towers, and roving patrols also serves as a psychological deterrent to the potential ground intrusion sensors between an outer and an inner barrier. This visible 'hardness' of a high-value asset makes airborne penetration more attractive, even though the airborne intruder may require training in the use of an aircraft or other airborne conveyance system. Certain airborne intrusion scenarios allow an adversary to penetrate much deeper and faster through delay and defense systems designed to deter the ground intruder. Since an airborne intruder can quickly reach the high-value asset, early detection critical to asset defense. Early detection of the airborne intruder also ensures appropriate use of the deadly force doctrine because the guard force has time to coordinate the response.

  9. Airborne exposure patterns from a passenger source in aircraft cabins

    PubMed Central

    Bennett, James S.; Jones, Byron W.; Hosni, Mohammad H.; Zhang, Yuanhui; Topmiller, Jennifer L.; Dietrich, Watts L.

    2015-01-01

    Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins. PMID:26526769

  10. Stability of airborne microbes in the Louvre Museum over time.

    PubMed

    Gaüzère, C; Moletta-Denat, M; Blanquart, H; Ferreira, S; Moularat, S; Godon, J-J; Robine, E

    2014-02-01

    The microbial content of air has as yet been little described, despite its public health implications, and there remains a lack of environmental microbial data on airborne microflora in enclosed spaces. In this context, the aim of this study was to characterize the diversity and dynamics of airborne microorganisms in the Louvre Museum using high-throughput molecular tools and to underline the microbial signature of indoor air in this human-occupied environment. This microbial community was monitored for 6 month during occupied time. The quantitative results revealed variations in the concentrations of less than one logarithm, with average values of 10(3) and 10(4) Escherichia coli/Aspergillus fumigatus genome equivalent per m(3) for bacteria and fungi, respectively. Our observations highlight the stability of the indoor airborne bacterial diversity over time, while the corresponding eukaryote community was less stable. Bacterial diversity characterized by pyrosequencing 454 showed high diversity dominated by the Proteobacteria which represented 51.1%, 46.9%, and 38.4% of sequences, for each of the three air samples sequenced. A common bacterial diversity was underlined, corresponding to 58.4% of the sequences. The core species were belonging mostly to the Proteobacteria and Actinobacteria, and to the genus Paracoccus spp., Acinetobacter sp., Pseudomonas sp., Enhydrobacter sp., Sphingomonas sp., Staphylococcus sp., and Streptococcus sp. PMID:23710880

  11. Airborne trace contaminants of possible interest in CELSS

    NASA Technical Reports Server (NTRS)

    Garavelli, J. S.

    1986-01-01

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

  12. Some aspects of the airborne transmission of infection

    PubMed Central

    Clark, Raymond P.; de Calcina-Goff, Mervyn L.

    2009-01-01

    The relationship between the human body and the dissemination of potentially pathogenic particles and droplets is described. Airborne transmission of infection in operating theatres and a burns unit and the part played by the human microclimate and its interaction with ventilating air flows is discussed. The mechanisms by which different garment assemblies used for surgery can enhance particle dispersion are illustrated and the way that floor cleaning can increase the concentration of airborne organisms is described. The development of the successful use of ultra-clean air systems in orthopaedic implant surgery is reviewed. Relationships between contact and airborne transmission of disease are explored and ways by which containment strategies and metrics used in pharmaceutical and electronics manufacturing can be applied to the design and monitoring of healthcare areas is discussed. It is suggested that currently available techniques involving architectural, ventilation and operational aspects of healthcare provision, when properly applied, can markedly improve treatment outcomes that may otherwise be compromised by hospital-acquired infections involving both bacteria and viruses. PMID:19815574

  13. Airborne exposure patterns from a passenger source in aircraft cabins.

    PubMed

    Bennett, James S; Jones, Byron W; Hosni, Mohammad H; Zhang, Yuanhui; Topmiller, Jennifer L; Dietrich, Watts L

    2013-01-01

    Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins. PMID:26526769

  14. Evaluation of source model coupled computational fluid dynamics (CFD) simulation of the dispersion of airborne contaminants in a work environment.

    PubMed

    Salim, S M; Viswanathan, Shekar; Ray, Madhumita Bhowmick

    2006-12-01

    Dispersion of airborne contaminants in indoor air was evaluated employing physical measurement, empirical models, and computer simulation methods. Field data collected from a tray of evaporating solvent in the laboratory were compared with computational fluid dynamics (CFD) simulations coupled with evaporation models. The results indicated that mathematical models of evaporation can be coupled with CFD simulations to produce reasonable qualitative predictions of airborne contaminant levels. The airflow pattern within a room is primarily determined by the room layout and the position of the air supply diffusers. Variations in ventilation rate did not alter the airflow pattern, thus generating a characteristic concentration profile of the airborne contaminants. PMID:17050350

  15. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  16. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  17. Comprehensive analysis of airborne contaminants from recent Spacelab missions

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  18. Effect of airborne particle on SO 2-calcite reaction

    NASA Astrophysics Data System (ADS)

    Böke, Hasan; Göktürk, E. Hale; Caner-Saltık, Emine N.; Demirci, Şahinde

    1999-02-01

    In modern urban atmosphere, sulphur dioxide (SO 2) attacks calcite (CaCO 3) in calcareous stone-producing gypsum (CaSO 4·2H 2O) which forms crust at rain sheltered surfaces and accelerates erosion at areas exposed to rain. The airborne particles collected on stone surfaces have always been considered to enhance the gypsum crust formation and thus it is believed that they should be removed from the surface to decrease the effects of SO 2. In this study, our aim was to investigate this event by carrying out a series of experiments in laboratory using pure calcium carbonate powder to represent calcareous stone. Sodium montmorillonite, activated carbon, ferric oxide, vanadium pentoxide and cupric chloride were mixed in the pure calcium carbonate powder as substitutes of the airborne particles in the polluted atmosphere. The samples have been exposed at nearly 10 ppmv SO 2 concentrations at 90% relative humidity conditions in a reaction chamber for several days. The mineralogical composition of the exposed samples were determined by X-ray diffraction (XRD) analysis and infrared spectrometer (IR). Sulphation reaction products, calcium sulphite hemihydrate, gypsum and unreacted calcite, were determined quantitatively using IR. Exposed samples have also been investigated morphologically using a scanning electron microscope (SEM). Experimental results reveal that calcium sulphite hemihydrate is the main reaction product of the SO 2-calcite reaction. It turns out that airborne particles play an important catalytic role in the oxidation of calcium sulphite hemihydrate into gypsum, although their presence does not very significantly affect the extent of sulphation reaction. This behaviour of airborne particles is explained by the presence of liquid film on the calcium carbonate surface where a series of reactions in the gas-liquid-solid interfaces takes place.

  19. Airborne elements, cell membranes, and chlorophyll in transplanted lichens

    SciTech Connect

    Garty, J.; Cohen, Y.; Kloog, N.

    1998-07-01

    The objective of the present study was to test the concentration of airborne mineral elements in the lichen Ramalina lacera (with.) J.R. Laund. in comparison with its physiological status. Thalli of Ramalina lacera were collected in a remote unpolluted site and transplanted in a polluted region for 10 mo. An analysis of 20 elements in addition to an analysis of the status of cell membranes and the integrity of chlorophyll was performed after this period of transplantation. The lichen manifested a great potential for the accumulation of Pb, V, Ni, Zn, and Cu. Potassium and P were found to leach out. High concentrations of Ni, Mg, and B coincided with damage caused to cell membranes. The integrity of chlorophyll correlated with the concentration of K and correlated inversely with the concentration of Cr, Fe, Mn, Ni, Pb, and B.

  20. Viability and potential for immigration of airborne bacteria from Africa that reach high mountain lakes in Europe.

    PubMed

    Hervàs, Anna; Camarero, Lluís; Reche, Isabel; Casamayor, Emilio O

    2009-06-01

    We have analysed the diversity of the bacteria, which grow after addition of concentrated airborne particles and desert dust in different microcosms combinations with water samples from oligotrophic alpine lakes. We used, on the one hand, airborne bacteria transported by an African dust plume and collected in a high mountain area in the central Pyrenees (Spain). On the other hand, we collected desert dust in Mauritania (c. 3000 km distance, and a few days estimated airborne journey), a known source region for dust storms in West Africa, which originates many of the dust plumes landing on Europe. In all the dust-amended treatments we consistently observed bacterial growth of common phyla usually found in freshwater ecosystems, i.e. Alpha-, Beta- and Gammaproteobacteria, Actinobacteria, and a few Bacteroidetes, but with different composition based on lake water pretreatment and dust type. Overall, we tentatively split the bacterial community in (i) typical freshwater non-airborne bacteria, (ii) cosmopolitan long-distance airborne bacteria, (iii) non-freshwater low-distance airborne bacteria, (iv) non-freshwater long-distance airborne soil bacteria and (v) freshwater non-soil airborne bacteria. We identified viable long-distance airborne bacteria as immigrants in alpine lakes (e.g. Sphingomonas-like) but also viable putative airborne pathogens with the potential to grow in remote alpine areas (Acinetobacter-like and Arthrobacter-like). Generation of atmospheric aerosols and remote dust deposition is a global process, largely enhanced by perturbations linked to the global change, and high mountain lakes are very convenient worldwide model systems for monitoring global-scale bacterial dispersion and pathogens entries in remote pristine environments. PMID:19453609

  1. 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...

  2. 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...

  3. 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...

  4. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 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...

  5. 30 CFR 33.32 - Determination of dust concentration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 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. Modis-N airborne simulator

    NASA Technical Reports Server (NTRS)

    Cech, Steven D.

    1992-01-01

    All required work associated with the above referenced contract has been successfully completed at this time. The Modis-N Airborne Simulator has been developed from existing AB184 Wildfire spectrometer parts as well as new detector arrays, optical components, and associated mechanical and electrical hardware. The various instrument components have been integrated into an operational system which has undergone extensive laboratory calibration and testing. The instrument has been delivered to NASA Ames where it will be installed on the NASA ER-2. The following paragraphs detail the specific tasks performed during the contract effort, the results obtained during the integration and testing of the instrument, and the conclusions which can be drawn from this effort.

  7. Airborne imaging spectrometer development tasks

    NASA Astrophysics Data System (ADS)

    Bolten, John

    The tasks that must be completed to design and build an airborne imaging spectrometer are listed. The manpower and resources required to do these tasks must be estimated by the people responsible for that work. The tasks are broken down by instrument subsystem or discipline. The instrument performance can be assessed at various stages during the development. The initial assessment should be done with the preliminary computer model. The instrument calibration facilities should be designed, but no calibration facilities are needed. The intermediate assessment can be done when the front end has been assembled. The preliminary instrument calibration facility should be available at this stage. The final assessment can only be done when the instrument is complete and ready for flight. For this, the final instrument calibration facility and the flight qualification facilities must be ready. The final assessment is discussed in each discipline under the section on integration and test.

  8. Research on MLS airborne antenna

    NASA Technical Reports Server (NTRS)

    Yu, C. L.; Burnside, W. D.

    1976-01-01

    Numerical solutions for the radiation patterns of antennas mounted on aircraft are developed. The airborne antenna problems associated with the Microwave Landing System (MLS) are emphasized. Based on the requirements of the MLS, volumetric pattern solutions are essential. Previous attempts at solving for the volumetric patterns were found to be far too complex and very inefficient. However as a result of previous efforts, it is possible to combine the elevation and roll plane pattern solutions to give the complete volumetric pattern. This combination is described as well as the aircraft simulation models used in the analysis. A numerical technique is presented to aid in the simulation of the aircraft studied. Finally, a description of the input data used in the computer code is given.

  9. Global deposition of airborne dioxin.

    PubMed

    Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

    2013-10-15

    We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others. PMID:23962732

  10. Airborne remote sensing of forest biomes

    NASA Technical Reports Server (NTRS)

    Sader, Steven A.

    1987-01-01

    Airborne sensor data of forest biomes obtained using an SAR, a laser profiler, an IR MSS, and a TM simulator are presented and examined. The SAR was utilized to investigate forest canopy structures in Mississippi and Costa Rica; the IR MSS measured forest canopy temperatures in Oregon and Puerto Rico; the TM simulator was employed in a tropical forest in Puerto Rico; and the laser profiler studied forest canopy characteristics in Costa Rica. The advantages and disadvantages of airborne systems are discussed. It is noted that the airborne sensors provide measurements applicable to forest monitoring programs.

  11. The Origin And Spread Of Airborne Bacteria

    NASA Astrophysics Data System (ADS)

    Henderson-Begg, S. K.; Moffett, B. F.

    2009-12-01

    The presence of bacteria in clouds may affect their radiation and precipitation properties as some species are able to catalyse the freezing of water at high temperatures (-2C to -10C). Where cloud-borne bacteria originate and the distances they are able to travel in the air remains a mystery. In this study we have attempted to address these issues by comparing metagenomic DNA sequences from air samples with those from other environmental sources. Air samples were collected on 1 July 2009 from a hill top at Thursley Nature Reserve in Surrey, United Kingdom, a rural site, 31 miles from the nearest stretch of coastline, and on 6 July 2009 from the top of a six storey building in Stratford on the East end of London, 38 miles from the nearest coastal area. Samples were collected using the Karcher DS5500 vacuum into a liquid filled collection vessel at an air flow rate of 3.3 m3 min-1 over a 4 hour period. Samples were then concentrated and the bacterial content was investigated by PCR, cloning and sequencing of 16S rRNA genes. During the collection period on 1 July the Royston Weather Station in the South East of England recorded wind speed of 1.9 miles/hour in an Easterly direction, with no cloud cover, relative humidity of 74% and atmospheric pressure of 1021.6 mB. On 6 July wind speed was 9.8 miles/hour in a South Westerly direction, there was light cloud cover, relative humidity was 73.8% and atmospheric pressure was 1002.8 mB. Twenty cloned 16S PCR products from each air sample were sequenced. The species identification of each clone is shown in Table 1. The diversity of bacteria found at both sites was similar, with Stenotrophomona and Pedobacteria species dominating both samples. When the DNA sequences were blasted against the environmental samples database, all sequences were found to display greatest homology to metagenomic DNA from marine sources. This may suggest that the most numerous bacteria in air samples originate in the oceans. Taking account of the

  12. 10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive...-infinite cloud of airborne radioactive material. The DACs listed in this appendix may be modified to...

  13. 10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive...-infinite cloud of airborne radioactive material. The DACs listed in this appendix may be modified to...

  14. 10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive...-infinite cloud of airborne radioactive material. The DACs listed in this appendix may be modified to...

  15. 10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive...-infinite cloud of airborne radioactive material. The DACs listed in this appendix may be modified to...

  16. Detecting Airborne Mercury by Use of Gold Nanowires

    NASA Technical Reports Server (NTRS)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Soler, Jessica; Mung, Nosang; Nix, Megan

    2009-01-01

    Like the palladium chloride (PdCl2) films described in the immediately preceding article, gold nanowire sensors have been found to be useful for detecting airborne elemental mercury at concentrations on the order of parts per billion (ppb). Also like the PdCl2 films, gold nanowire sensors can be regenerated under conditions much milder than those necessary for regeneration of gold films that have been used as airborne-Hg sensors. The interest in nanowire sensors in general is prompted by the expectation that nanowires of a given material covering a given surface may exhibit greater sensitivity than does a film of the same material because nanowires have a greater surface area. In preparation for experiments to demonstrate this sensor concept, sensors were fabricated by depositing gold nanowires, variously, on microhotplate or microarray sensor substrates. In the experiments, the electrical resistances were measured while the sensors were exposed to air at a temperature of 25 C and relative humidity of about 30 percent containing mercury at various concentrations from 2 to 70 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury at ppb concentrations in room-temperature air and can be regenerated by exposure to clean flowing air at temperatures <40 C.

  17. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect

    Glissmeyer, John A.

    2010-10-18

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  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. Detection of airborne bacteria with disposable bio-precipitator and NanoGene assay.

    PubMed

    Lee, Eun-Hee; Chua, Beelee; Son, Ahjeong

    2016-09-15

    We demonstrated the detection of airborne bacteria by a disposable bio-precipitator and NanoGene assay combination. The bio-precipitator employed micro corona discharge at 1960V and at less than 35µA to simultaneously charge, capture and lyse the airborne bacteria. This was enabled by the use of a 15μL liquid anode. Using a custom exposure setup, the target bacterium Bacillus subtilis in the atomization solution was rendered airborne. After exposure, the liquid anode in the bio-precipitator was subsequently measured for DNA concentration and analyzed with the NanoGene assay. As the bacterial concentration increased from 0.0104 to 42.6 g-DCW/L the released DNA concentration in the liquid anode increased from 2.10±1.57 to 75.00±7.15ng/μL. More importantly, the NanoGene assay showed an increase in normalized fluorescence (gene quantification) from 18.03±1.18 to 49.71±1.82 as the bacterial concentrations increased from 0.0104 to 42.6 g-DCW/L. the electrical power consumption of the bio-precipitator was shown to be amenable for portable use. In addition, the detection limit of bio-precipitator and NanoGene assay combination in the context of environmentally relevant levels of airborne bacteria was also discussed. PMID:27130988

  20. AIRBORNE TRACE ELEMENTS IN GREAT SMOKY MOUNTAINS, OLYMPIC, AND GLACIER NATIONAL PARKS

    EPA Science Inventory

    Airborne trace elements were studied at remote sites in three U.S. National Parks where crustal weathering, sea spray, and long-range transport of anthropogenic emissions were likely to influence concentrations. Levels of all elements studied except Pb were smaller in Great Smoky...

  1. THE AIRBORNE CULTURABLE MICROBIAL ECOLOGY OF SEVEN FEEDYARDS IN THE HIGH PLAINS OF TEXAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated animal feeding operations (CAFO) produce a large amount of manure that can impact the environment if not managed properly. Environmental issues at CAFO include odor, pathogens, endotoxins (ET), and dust. The role of ET and pathogens with dust emissions was investigated. Airborne microbi...

  2. Mapping of airborne Doppler radar data

    SciTech Connect

    Lee, W.; Dodge, P.; Marks, F.D. Jr.; Hildebrand, P.H. NOAA, Miami, FL )

    1994-04-01

    Two sets of equations are derived to (1) map airborne Doppler radar data from an aircraft-relative coordinate system to an earth-relative coordinate system, and (2) remove the platform motion from the observed Doppler velocities. These equations can be applied to data collected by the National Oceanic and Atmospheric Administration WP-3D system, the National Center for Atmospheric Research Electra Doppler Radar (ELDORA) system, and other airborne radar systems.

  3. Distribution and identification of culturable airborne microorganisms in a Swiss milk processing facility.

    PubMed

    Brandl, Helmut; Fricker-Feer, Claudia; Ziegler, Dominik; Mandal, Jyotshna; Stephan, Roger; Lehner, Angelika

    2014-01-01

    Airborne communities (mainly bacteria) were sampled and characterized (concentration levels and diversity) at 1 outdoor and 6 indoor sites within a Swiss dairy production facility. Air samples were collected on 2 sampling dates in different seasons, one in February and one in July 2012 using impaction bioaerosol samplers. After cultivation, isolates were identified by mass spectrometry (matrix-assisted laser desorption/ionization-time-of-flight) and molecular (sequencing of 16S rRNA and rpoB genes) methods. In general, total airborne particle loads and total bacterial counts were higher in winter than in summer, but remained constant within each indoor sampling site at both sampling times (February and July). Bacterial numbers were generally very low (<100 cfu/m(3) of air) during the different steps of milk powder production. Elevated bacterial concentrations (with mean values of 391 ± 142 and 179 ± 33 cfu/m(3) of air during winter and summer sampling, respectively; n=15) occurred mainly in the "logistics area," where products in closed tins are packed in secondary packaging material and prepared for shipping. However, total bacterial counts at the outdoor site varied, with a 5- to 6-fold higher concentration observed in winter compared with summer. Twenty-five gram-positive and gram-negative genera were identified as part of the airborne microflora, with Bacillus and Staphylococcus being the most frequent genera identified. Overall, the culturable microflora community showed a composition typical and representative for the specific location. Bacterial counts were highly correlated with total airborne particles in the size range 1 to 5 µm, indicating that a simple surveillance system based upon counting of airborne particles could be implemented. The data generated in this study could be used to evaluate the effectiveness of the dairy plant's sanitation program and to identify potential sources of airborne contamination, resulting in increased food safety. PMID

  4. Challenges and opportunities of airborne metagenomics.

    PubMed

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-05-01

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. PMID:25953766

  5. Challenges and Opportunities of Airborne Metagenomics

    PubMed Central

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-01-01

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. PMID:25953766

  6. Anthropogenic Osmium in Airborne Particles from Woods Hole, Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    Peucker-Ehrenbrink, B.; Sen, I. S.; Geboy, N.

    2012-12-01

    The global geochemical cycle of osmium has been significantly disturbed by the introduction of automobile exhaust catalysts to convert noxious gas emissions into more benign forms. Anthropogenic osmium has been reported in rainwater, snow, and in the urban airborne particles from around the world to reveal global-scale osmium pollution [1, 2]. In this study, we report on the platinum group element (PGE) concentrations and osmium isotope ratios of airborne particles (PM10) collected in Woods Hole, a small coastal town in Massachusetts to better understand inputs of anthropogenic osmium to rural environments. We further investigate the use of osmium isotopes to track sources of airborne particles and support source apportionment studies on a continental scale. The samples used in this study were collected at Woods Hole Oceanographic Institution over one year (2008-2009). From this collection twelve samples for which the backward air mass trajectories have been determined were selected for osmium isotope analyses. Our results show that the osmium and platinum concentrations are an order of magnitude lower when compared to downtown Boston [2]. The average Os, Pt and Ir concentrations are 0.006±0.012, 0.019±0.023, and 0.685±0.634 pg m-3, respectively. The 187Os/188Os of the aerosols range from 0.275 to 0.788. As continental crust is radiogenic (187Os/188Os >1) and PGE ore bodies generally have unradiogenic 187Os/188Os (~0.2), the unradiogenic 187Os/188Os signature of the aerosols indicates anthropogenic contributions. With 95% of the total osmium mobilization on land being attributed to human activities [3], it is clear that human imprint on airborne particles is not restricted to urban centers with high traffic flows, but also affects rural environments. Aerosol particles that have backward air mass trajectories from the Southwest, the densely populated and industrialized Eastern seaboard, are characterized by unradiogenic osmium, while air masses from the North

  7. Chemical composition of urban airborne particulate matter in Ulaanbaatar

    NASA Astrophysics Data System (ADS)

    Nishikawa, Masataka; Matsui, Ichiro; Batdorj, Dashdondog; Jugder, Dulam; Mori, Ikuko; Shimizu, Atsushi; Sugimoto, Nobuo; Takahashi, Katsuyuki

    2011-10-01

    Atmospheric pollution caused by airborne particulate matter in the winter season in Ulaanbaatar, Mongolia is a very serious problem. However, there is a complete lack of scientific observation data to define the situation prior to any remediation. PM10 and PM2.5 average monthly values obtained by continuous monitoring showed the concentrations of particles of both size categories exceeded 100 μg m-3 during November to February (winter). PM10 particles were sampled with filters in January (i.e. during the heating period) and June (i.e.non-heating period) of 2008 in central Ulaanbaatar. To determine the composition of urban airborne particulate matter we analyzed a range of ionic components, multiple elements including heavy metals, and organic and inorganic carbon (soot). We also measured the stable carbon isotope ratio of the soot. Total carbon (sum of organic carbon and inorganic carbon) accounted for 47% of the mass of the PM10 during the heating period and 33% during the non-heating period, and was the largest component of urban airborne particulate matter in Ulaanbaatar. Stable isotope ratios (δ13C) of soot generated during the heating period (-23.4 ± 0.2‰) approximated the ratios for coal used in Ulaanbaatar (-21.3 to -24.4‰), while the ratios during the non-heating period (-27.1 ± 0.4‰) were clearly different from the coal values. In the heating period, a very high correlation was observed between soot and organic carbon, SO42-, NO3-, F-, Zn, As, and Pb, and we concluded that they were derived from coal combustion along with soot. In addition, the concentrations and their ratios relative to each other of Al, Fe, Ca, K, Na, Mg, and Mn hardly differed between the heating period and the non-heating period, and it was concluded that they were derived from soil dust.

  8. Pulsed Doppler lidar airborne scanner

    NASA Technical Reports Server (NTRS)

    Dimarzio, C. A.; Mcvicker, D. B.; Morrow, C. E.; Negus, C. C.

    1985-01-01

    This report covers the work accomplished during the reporting period on Pulsed Doppler Lidar Airborne Scanner and describes plans for the next reporting period. The objectives during the current phase of the contract are divided into four phases. Phase 1 includes ground testing of the system and analysis of data from the 1981 Severe Storms Test Flights. Phase 2 consists of preflight preparation and planning for the 1983 flight series. The flight test itself will be performed during Phase 3, and Phase 4 consists of post-flight analysis and operation of the system after that flight test. The range profile from five samples taken during Flight 10, around 1700 Z is given. The lowest curve is taken from data collected upwind of Mt. Shasta at about 10,000 feet of altitude, in a clear atmosphere, where no signals were observed. It thus is a good representation of the noise level as a function of range. The next curve was taken downwind of the mountain, and shows evidence of atmospheric returns. There is some question as to whether the data are valid at all ranges, or some ranges are contaminated by the others.

  9. Pulsed Doppler lidar airborne scanner

    NASA Astrophysics Data System (ADS)

    Dimarzio, C. A.; McVicker, D. B.; Morrow, C. E.; Negus, C. C.

    1985-10-01

    This report covers the work accomplished during the reporting period on Pulsed Doppler Lidar Airborne Scanner and describes plans for the next reporting period. The objectives during the current phase of the contract are divided into four phases. Phase 1 includes ground testing of the system and analysis of data from the 1981 Severe Storms Test Flights. Phase 2 consists of preflight preparation and planning for the 1983 flight series. The flight test itself will be performed during Phase 3, and Phase 4 consists of post-flight analysis and operation of the system after that flight test. The range profile from five samples taken during Flight 10, around 1700 Z is given. The lowest curve is taken from data collected upwind of Mt. Shasta at about 10,000 feet of altitude, in a clear atmosphere, where no signals were observed. It thus is a good representation of the noise level as a function of range. The next curve was taken downwind of the mountain, and shows evidence of atmospheric returns. There is some question as to whether the data are valid at all ranges, or some ranges are contaminated by the others.

  10. Performance Basis for Airborne Separation

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    2008-01-01

    Emerging applications of Airborne Separation Assistance System (ASAS) technologies make possible new and powerful methods in Air Traffic Management (ATM) that may significantly improve the system-level performance of operations in the future ATM system. These applications typically involve the aircraft managing certain components of its Four Dimensional (4D) trajectory within the degrees of freedom defined by a set of operational constraints negotiated with the Air Navigation Service Provider. It is hypothesized that reliable individual performance by many aircraft will translate into higher total system-level performance. To actually realize this improvement, the new capabilities must be attracted to high demand and complexity regions where high ATM performance is critical. Operational approval for use in such environments will require participating aircraft to be certified to rigorous and appropriate performance standards. Currently, no formal basis exists for defining these standards. This paper provides a context for defining the performance basis for 4D-ASAS operations. The trajectory constraints to be met by the aircraft are defined, categorized, and assessed for performance requirements. A proposed extension of the existing Required Navigation Performance (RNP) construct into a dynamic standard (Dynamic RNP) is outlined. Sample data is presented from an ongoing high-fidelity batch simulation series that is characterizing the performance of an advanced 4D-ASAS application. Data of this type will contribute to the evaluation and validation of the proposed performance basis.

  11. Medicinal smoke reduces airborne bacteria.

    PubMed

    Nautiyal, Chandra Shekhar; Chauhan, Puneet Singh; Nene, Yeshwant Laxman

    2007-12-01

    This study represents a comprehensive analysis and scientific validation of our ancient knowledge about the effect of ethnopharmacological aspects of natural products' smoke for therapy and health care on airborne bacterial composition and dynamics, using the Biolog microplate panels and Microlog database. We have observed that 1h treatment of medicinal smoke emanated by burning wood and a mixture of odoriferous and medicinal herbs (havan sámagri=material used in oblation to fire all over India), on aerial bacterial population caused over 94% reduction of bacterial counts by 60 min and the ability of the smoke to purify or disinfect the air and to make the environment cleaner was maintained up to 24h in the closed room. Absence of pathogenic bacteria Corynebacterium urealyticum, Curtobacterium flaccumfaciens, Enterobacter aerogenes (Klebsiella mobilis), Kocuria rosea, Pseudomonas syringae pv. persicae, Staphylococcus lentus, and Xanthomonas campestris pv. tardicrescens in the open room even after 30 days is indicative of the bactericidal potential of the medicinal smoke treatment. We have demonstrated that using medicinal smoke it is possible to completely eliminate diverse plant and human pathogenic bacteria of the air within confined space. PMID:17913417

  12. Visualizing Airborne and Satellite Imagery

    NASA Technical Reports Server (NTRS)

    Bierwirth, Victoria A.

    2011-01-01

    Remote sensing is a process able to provide information about Earth to better understand Earth's processes and assist in monitoring Earth's resources. The Cloud Absorption Radiometer (CAR) is one remote sensing instrument dedicated to the cause of collecting data on anthropogenic influences on Earth as well as assisting scientists in understanding land-surface and atmospheric interactions. Landsat is a satellite program dedicated to collecting repetitive coverage of the continental Earth surfaces in seven regions of the electromagnetic spectrum. Combining these two aircraft and satellite remote sensing instruments will provide a detailed and comprehensive data collection able to provide influential information and improve predictions of changes in the future. This project acquired, interpreted, and created composite images from satellite data acquired from Landsat 4-5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper plus (ETM+). Landsat images were processed for areas covered by CAR during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCT AS), Cloud and Land Surface Interaction Campaign (CLASIC), Intercontinental Chemical Transport Experiment-Phase B (INTEXB), and Southern African Regional Science Initiative (SAFARI) 2000 missions. The acquisition of Landsat data will provide supplemental information to assist in visualizing and interpreting airborne and satellite imagery.

  13. Exposure to airborne fungi and bacteria while commuting in passenger cars and public buses

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hyun; Jo, Wan-Kuen

    The present study examined airborne microbe levels inside and outside passenger cars and public buses during two seasons (winter and summer). The prevalence level of individual fungal genera depended on the fungi and agar type, whereas a constant higher prevalence (>90%) was found for the total bacteria and total fungi. The four most prevalent fungal genera were Cladosporium, Penicillium, Aspergillus, and Alternaria in a descending order. The major parameters associated with the airborne microbe measurements included agar type, vehicle type, and seasonal variation. When compared to the malt extract agar (MEA), the dichloran glycerol 18 agar (DG-18) was found to produce better counts for the target fungi. The summer in-vehicle bacterial concentrations were significantly higher for public buses than for the passenger cars, whereas the reverse was true for summer in-vehicle total fungal concentrations. This pattern was also consistent with summer outdoor results. In contrast, the winter in-vehicle and outdoor airborne microbe levels were similar for cars and buses. Meanwhile, summer was generally found to have higher in-vehicle fungal concentrations than winter. The current in-vehicle airborne microbe concentrations were found to be similar to residential indoor values from other reports, such as bacterial values between 10 and 10 3 CFU m -3 and total fungal aerosol concentrations ranging from 10 to 10 3 CFU m -3. It was suggested that motor vehicles in which many individuals spend a certain percentage of their day or week for travel are also a potential microenvironment for individual exposure to airborne microbes.

  14. Airborne spread of foot-and-mouth disease in Saskatchewan, Canada, 1951-1952.

    PubMed Central

    Daggupaty, S M; Sellers, R F

    1990-01-01

    Farms affected with foot-and-mouth disease during the epidemic in Saskatchewan, in 1951-1952, for which the origin of virus was not known or uncertain, were studied to determine if infection could have been introduced by the airborne route. A short-range Gaussian plume dispersion model was used to estimate the concentration of virus downwind and the dose available for individual animals. The investigation suggested that a large virus source due to infected pigs in a feedlot in January 1952 could have been responsible for airborne dispersion northwestwards downwind to farms up to 20 km distant. Subsequent spread from these farms was to neighboring farms and was influenced by the local topography of a creek. The dispersion model could be used for predicting airborne spread if foot-and-mouth disease should occur. PMID:2174297

  15. Laboratory experiments on membrane filter sampling of airborne mycotoxins produced by Stachybotrys atra corda

    NASA Astrophysics Data System (ADS)

    Pasanen, A.-L.; Nikulin, M.; Tuomainen, M.; Berg, S.; Parikka, P.; Hintikka, E.-L.

    A membrane filter method for sampling of airborne stachybotrystoxins was studied in the laboratory. Toxigenic strains of Stachybotrys atra on wallpaper, grain, hay and straw were used as toxin sources in the experiments. Air samples were collected on cellulose nitrate and polycarbonate membrane filters at air flow rates of 10-20 ℓ min -1. After the filter sampling, the air was passed through methanol. The results showed that stachybotrystoxins (trichothecenes) were concentrated in airborne fungal propagules, and thus can be collected on filters. Polycarbonate filters with a pore size of 0.2 μm collected the highest percentage of toxic samples. The laboratory experiments indicated that polycarbonate filter sampling for the collection of airborne mycotoxins is a promising method for extension to field measurements.

  16. Personal exposure to airborne dust and microorganisms in agricultural environments.

    PubMed

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

    2006-03-01

    Airborne dust and microorganisms are associated with respiratory diseases and increased mortality and morbidity. Farmers are at high risk of exposure to both of these hazards. Very limited information, however, is available on the combined exposures to both hazards on different types of farms. Moreover, most of the previous studies have measured the mass concentration of particles ignoring the particle size. In this study, farmers' exposure to airborne dust and microorganisms was studied using our newly developed personal sampling system. Particle number concentration and size distribution were measured with an optical particle counter. Simultaneously, particles were collected on a filter and analyzed for microorganisms. The field measurements were conducted in animal confinements (swine, poultry, and dairy) and during grain harvesting (corn and soybean). The results show the following average concentrations on the workers' breathing zone: 1.7 x 10(6) to 2.9 x 10(7) particles/m(3) for total dust, 0.9 x 10(3) to 3.9 x 10(4) spores/m(3) for total fungal spores, 0.3 x 10(3) to 3.6 x 10(4)CFU/m(3) for culturable fungal spores, 0.3 x 10(4) to 3.3 x 10(8) CFU/m(3) for culturable bacteria, and limit of detection (LOD) to 2.8 x 10(3) CFU/m(3) for culturable actinomycetes in animal confinements. The respective concentrations were 4.4 x 10(6) to 5.8 x 10(7) particles/m(3), 3.4 x 10(4) to 6.1 x 10(6) spores/m(3), 8.2 x 10(4) to 7.4 x 10(6) CFU/m(3), 0.4 x 10(5) to 1.4 x 10(6) CFU/m(3), and LOD to 2.6 x 10(4) CFU/m(3) during grain harvesting. The highest contribution of large particles (3-10 microm) in total particles was found during grain harvesting, whereas the size distribution was dominated by smaller particles (< 3 microm) in animal confinements. High fraction (up to 37%) of particles between 2-10 microm was found to be fungal spores. The results indicate that an increase in the concentration of large dust particles (2-10 microm) during grain harvesting was partially

  17. Assessment of the Levels of Airborne Bacteria, Gram-Negative Bacteria, and Fungi in Hospital Lobbies

    PubMed Central

    Park, Dong-Uk; Yeom, Jeong-Kwan; Lee, Won Jae; Lee, Kyeong-Min

    2013-01-01

    Aims: We assessed the levels of airborne bacteria, Gram-negative bacteria (GNB), and fungi in six hospital lobbies, and investigated the environmental and hospital characteristics that affected the airborne microorganism levels. Methods: An Andersen single-stage sampler equipped with appropriate nutrition plate agar was used to collect the samples. The three types of microorganisms were repeatedly collected at a fixed location in each hospital (assumed to be representative of the entire hospital lobby) from 08:00 through 24:00, with a sampling time of less than 5 min. Temperature and relative humidity were simultaneously monitored. Results: Multiple regression analysis was used to identify the major factors affecting microorganism levels. The average levels of bacteria (7.2 × 102 CFU/m3), GNB (1.7 × 10 CFU/m3), and fungi (7.7 × 10 CFU/m3) indicated that all hospital lobbies were generally contaminated. Season was the only factor that significantly affected the levels of all microorganisms (p < 0.0001), where contamination was the highest during the summer, significantly higher than during the winter. Other significant factors varied by microorganism, as follows: airborne bacteria (number of people in the lobby, sampling time), GNB (scale of hospital), and fungi (humidity and air temperature). Conclusions: Hospital lobby air was generally contaminated with microorganisms, including bacteria, GNB, and fungi. Environmental factors that may significantly influence the airborne concentrations of these agents should be managed to minimize airborne levels. PMID:23435586

  18. Detection of Airborne Lactococcal Bacteriophages in Cheese Manufacturing Plants▿

    PubMed Central

    Verreault, Daniel; Gendron, Louis; Rousseau, Geneviève M.; Veillette, Marc; Massé, Daniel; Lindsley, William G.; Moineau, Sylvain; Duchaine, Caroline

    2011-01-01

    The dairy industry adds starter bacterial cultures to heat-treated milk to control the fermentation process during the manufacture of many cheeses. These highly concentrated bacterial populations are susceptible to virulent phages that are ubiquitous in cheese factories. In this study, the dissemination of these phages by the airborne route and their presence on working surfaces were investigated in a cheese factory. Several surfaces were swabbed, and five air samplers (polytetrafluoroethylene filter, polycarbonate filter, BioSampler, Coriolis cyclone sampler, and NIOSH two-stage cyclone bioaerosol personal sampler) were tested. Samples were then analyzed for the presence of two Lactococcus lactis phage groups (936 and c2), and quantification was done by quantitative PCR (qPCR). Both lactococcal phage groups were found on most swabbed surfaces, while airborne phages were detected at concentrations of at least 103 genomes/m3 of air. The NIOSH sampler had the highest rate of air samples with detectable levels of lactococcal phages. This study demonstrates that virulent phages can circulate through the air and that they are ubiquitous in cheese manufacturing facilities. PMID:21115712

  19. New Methods for Personal Exposure Monitoring for Airborne Particles.

    PubMed

    Koehler, Kirsten A; Peters, Thomas M

    2015-12-01

    Airborne particles have been associated with a range of adverse cardiopulmonary outcomes, which has driven its monitoring at stationary central sites throughout the world. Individual exposures, however, can differ substantially from concentrations measured at central sites due to spatial variability across a region and sources unique to the individual, such as cooking or cleaning in homes, traffic emissions during commutes, and widely varying sources encountered at work. Personal monitoring with small, battery-powered instruments enables the measurement of an individual's exposure as they go about their daily activities. Personal monitoring can substantially reduce exposure misclassification and improve the power to detect relationships between particulate pollution and adverse health outcomes. By partitioning exposures to known locations and sources, it may be possible to account for variable toxicity of different sources. This review outlines recent advances in the field of personal exposure assessment for particulate pollution. Advances in battery technology have improved the feasibility of 24-h monitoring, providing the ability to more completely attribute exposures to microenvironment (e.g., work, home, commute). New metrics to evaluate the relationship between particulate matter and health are also being considered, including particle number concentration, particle composition measures, and particle oxidative load. Such metrics provide opportunities to develop more precise associations between airborne particles and health and may provide opportunities for more effective regulations. PMID:26385477

  20. New Methods for Personal Exposure Monitoring for Airborne Particles

    PubMed Central

    Koehler, Kirsten A.; Peters, Thomas

    2016-01-01

    Airborne particles have been associated with a range of adverse cardiopulmonary outcomes, which has driven its monitoring at stationary, central sites throughout the world. Individual exposures, however, can differ substantially from concentrations measured at central sites due to spatial variability across a region and sources unique to the individual, such as cooking or cleaning in homes, traffic emissions during commutes, and widely varying sources encountered at work. Personal monitoring with small, battery-powered instruments enables the measurement of an individual’s exposure as they go about their daily activities. Personal monitoring can substantially reduce exposure misclassification and improve the power to detect relationships between particulate pollution and adverse health outcomes. By partitioning exposures to known locations and sources, it may be possible to account for variable toxicity of different sources. This review outlines recent advances in the field of personal exposure assessment for particulate pollution. Advances in battery technology have improved the feasibility of 24-hour monitoring, providing the ability to more completely attribute exposures to microenvironment (e.g., work, home, commute). New metrics to evaluate the relationship between particulate matter and health are also being considered, including particle number concentration, particle composition measures, and particle oxidative load. Such metrics provide opportunities to develop more precise associations between airborne particles and health and may provide opportunities for more effective regulations. PMID:26385477

  1. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms.

    PubMed

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-01-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration. PMID:26522006

  2. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    PubMed Central

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-01-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration. PMID:26522006

  3. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    NASA Astrophysics Data System (ADS)

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-11-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration.

  4. NASA's Coastal and Ocean Airborne Science Testbed

    NASA Astrophysics Data System (ADS)

    Guild, L. S.; Dungan, J. L.; Edwards, M.; Russell, P. B.; Morrow, J. H.; Hooker, S.; Myers, J.; Kudela, R. M.; Dunagan, S.; Soulage, M.; Ellis, T.; Clinton, N. E.; Lobitz, B.; Martin, K.; Zell, P.; Berthold, R. W.; Smith, C.; Andrew, D.; Gore, W.; Torres, J.

    2011-12-01

    The Coastal and Ocean Airborne Science Testbed (COAST) Project is a NASA Earth-science flight mission that will advance coastal ecosystems research by providing a unique airborne payload optimized for remote sensing in the optically complex coastal zone. Teaming NASA Ames scientists and engineers with Biospherical Instruments, Inc. (San Diego) and UC Santa Cruz, the airborne COAST instrument suite combines a customized imaging spectrometer, sunphotometer system, and a new bio-optical radiometer package to obtain ocean/coastal/atmosphere data simultaneously in flight for the first time. The imaging spectrometer (Headwall) is optimized in the blue region of the spectrum to emphasize remote sensing of marine and freshwater ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data will be accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Based on optical detectors called microradiometers, the NASA Ocean Biology and Biogeochemistry Calibration and Validation (cal/val) Office team has deployed advanced commercial off-the-shelf instrumentation that provides in situ measurements of the apparent optical properties at the land/ocean boundary including optically shallow aquatic ecosystems (e.g., lakes, estuaries, coral reefs). A complimentary microradiometer instrument package (Biospherical Instruments, Inc.), optimized for use above water, will be flown for the first time with the airborne instrument suite. Details of the October 2011 COAST airborne mission over Monterey Bay demonstrating this new airborne instrument suite capability will be presented, with associated preliminary data on coastal ocean color products, coincident spatial and temporal data on aerosol optical depth and water vapor column content, as well as derived exact water-leaving radiances.

  5. The impact of fireworks on airborne particles

    NASA Astrophysics Data System (ADS)

    Vecchi, Roberta; Bernardoni, Vera; Cricchio, Diana; D'Alessandro, Alessandra; Fermo, Paola; Lucarelli, Franco; Nava, Silvia; Piazzalunga, Andrea; Valli, Gianluigi

    Fireworks are one of the most unusual sources of pollution in atmosphere; although transient, these pollution episodes are responsible for high concentrations of particles (especially metals and organic compounds) and gases. In this paper, results of a study on chemical-physical properties of airborne particles (elements, ions, organic and elemental carbon and particles size distributions) collected during a fireworks episode in Milan (Italy) are reported. Elements typically emitted during pyrotechnic displays increased in 1 h as follows: Sr (120 times), Mg (22 times), Ba (12 times), K (11 times), and Cu (6 times). In our case study, Sr was recognised as the best fireworks tracer because its concentration was very high during the event and lower than, or comparable with, minimum detection limits during other time intervals, suggesting that it was mainly due to pyrotechnic displays. In addition, particles number concentrations increased significantly during the episode (up to 6.7 times in 1 h for the 0.5< d<1 μm size bin). Contributions (e.g. Cu, elemental carbon and nitrogen oxides) to air pollution due to the large traffic volume registered during the same night were also singled out. The original application of Positive Matrix Factorisation and Multiple Linear Regression allowed, as far as we know, here for the first time, the quantification of the fireworks contribution to atmospheric particulate matter (PM) and the resolution of their chemical profile. The contribution of fireworks to the local environment in terms of PM 10 mass, elements and chemical components was assessed with 4-h time resolution. PM 10 mass apportioned by fireworks was up to 33.6 μg m -3 (about 50% of the total PM 10 mass). Major contributors were elemental and organic carbon (2.8 and 8.1 μg m -3, respectively) as well as metals like Mg, K, Sr, Ba, and Cu (0.4, 0.7, 0.07, 0.1, and 0.1 μg m -3, respectively).

  6. Airborne DOAS in South Africa: escaping flatland

    NASA Astrophysics Data System (ADS)

    Broccardo, S. P.; Heue, K.; Piketh, S.; Platt, U.

    2010-12-01

    The satellite instruments SCIAMACHY, OMI and GOME-2 show high average tropospheric NO2 vertical column densities over the South African Highveld, a region with a high density of coal-fired power stations and other heavy industries. A pushbroom-imaging DOAS spectrometer was flown over the Highveld and surrounding areas in order to further investigate this feature of the satellite record. The wavelength range of the instrument includes differential absorption structures of gases relevant to air quality such as NO2 and SO2. The high spatial resolution of the instrument allows individual sources to be distinguished, while the mobility of the airborne platform allows larger-scale measurements to be made. Emissions fluxes for individual facilities are calculated. An NO flux for the city of Johannesburg is derived from the nadir DOAS column measurements. Similarly, a flux for the entire Highveld region is derived and compared to a satellite-derived flux. The Highveld provides an excellent outdoor laboratory for development of trace-gas remote sensing instrumentation. The greater Johannesburg conurbation and nearby industrial point sources are surrounded by rural areas for several hundred kilometers on all sides. Flat topography and a stable atmosphere in winter lead to plumes with high trace-gas concentrations that are easy to measure and distinguish from the background. A lightweight scanning multi-axis spectrometer is being built to measure industrial plumes from an ultra-light aircraft. Using a tomographic inversion, this instrument will give a vertical cross-section of the plume, allowing validation of dispersion models and direct comparison with in-situ measurements. Using a suitable flight path, a three dimensional representation of the plume can be built up.

  7. Concentrator Systems

    NASA Astrophysics Data System (ADS)

    Luque-Heredia, Ignacio; Luque, Antonio

    2015-10-01

    The following sections are included: * Introduction * The early development of CPV * Concentrator solar cells * Optics for photovoltaic concentrators * Photovoltaic concentration modules * Tracking systems for photovoltaic concentration * High-concentration systems * Rating and performance * Cost considerations * Conclusions * References

  8. Prevalence of culturable airborne spores of selected allergenic and pathogenic fungi in outdoor air

    NASA Astrophysics Data System (ADS)

    O'Gorman, Céline M.; Fuller, Hubert T.

    2008-06-01

    Temporal and spatial variations in airborne spore concentrations of selected allergenic and pathogenic fungi were examined in Dublin, Ireland, in 2005. Air samples were taken at four outdoor locations in the city every 2 weeks, coupled with measurements of meteorological conditions. Total culturable airborne fungal spore concentrations in Dublin ranged from 30-6800 colony forming units per cubic metre of air (CFU m-3) over the 12-month period. Cladosporium, Penicillium, Aspergillus and Alternaria spores were constantly present in the Dublin atmosphere, representing >20% of the total culturable spore count. Concentrations of Cladosporium increased significantly in summer and reached allergenic threshold levels, peaking at over 3200 CFU m-3 in August. Penicillium spore concentrations never reached allergenic threshold levels, with average concentrations of <150 CFU m-3. Alternaria conidia formed only 0.3% of the total culturable fungal spore count and concentrations never exceeded 50 CFU m-3, attributable to the coastal position of Dublin and its low levels of arable production. The opportunistic human pathogen Aspergillus fumigatus was present throughout the year in nominal concentrations (<10 CFU m-3), but sporadic high counts were also recorded (300-400 CFU m-3), the potential health implications of which give cause for concern. Spores of neither Cryptococcus neoformans nor Stachybotrys chartarum were detected, but airborne basidiospores of Schizophyllum commune were evidenced by the dikaryotization of monokaryon tester strains following exposure to the air. The relationships between airborne fungal spore concentrations and meteorological factors were analysed by redundancy analysis and revealed positive correlations between temperature and Cladosporium and relative humidity and Penicillium and Aspergillus.

  9. Airborne lead and other elements derived from local fires in the himalayas.

    PubMed

    Davidson, C I; Grimm, T C; Nasta, M A

    1981-12-18

    The combustion of wood and yak dung for heating and cooking in a populated Nepal Himalayan valley contributes significantly to the ambient airborne concentrations of lead, copper, aluminum, magnesium, and elemental and organic carbon. A comparison of the concentrations of these elements in fresh snow with corresponding values in air suggests that the pollution aerosol is confined to the valley, with pristine air aloft. PMID:17812260

  10. High Energy 2-Micron Solid-State Laser Transmitter for NASA's Airborne CO2 Measurements

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Bai, Yingxin

    2012-01-01

    A 2-micron pulsed, Integrated Path Differential Absorption (IPDA) lidar instrument for ground and airborne atmospheric CO2 concentration measurements via direct detection method is being developed at NASA Langley Research Center. This instrument will provide an alternate approach to measure atmospheric CO2 concentrations with significant advantages. A high energy pulsed approach provides high-precision measurement capability by having high signal-to-noise level and unambiguously eliminates the contamination from aerosols and clouds that can bias the IPDA measurement.

  11. The manned hydrogen balloon - an appropriate platform for airborne Lagrange experiments in atmospheric research

    SciTech Connect

    Rabl, P.F.H.; Euskirchen, J.

    1996-10-01

    During the last decade hydrogen ballooning provided a reliable basis for special airborne measurements especially for experiments that give evidence about atmospheric chemistry and structure. Although the balloon is not quite a small particle without inertia, Lagrange-like movements of atmospheric mass can be simulated. During two experiments, the vertical gradients of ozone concentration were measured in the downwind area of Munich. The results show remarkable differences in ozone concentration and production, dependent of the daytime. 3 refs., 3 figs.

  12. Mapping permafrost with airborne electromagnetics

    NASA Astrophysics Data System (ADS)

    Minsley, B. J.; Ball, L. B.; Bloss, B. R.; Kass, A.; Pastick, N.; Smith, B. D.; Voss, C. I.; Walsh, D. O.; Walvoord, M. A.; Wylie, B. K.

    2014-12-01

    Permafrost is a key characteristic of cold region landscapes, yet detailed assessments of how the subsurface distribution of permafrost impacts the environment, hydrologic systems, and infrastructure are lacking. Data acquired from several airborne electromagnetic (AEM) surveys in Alaska provide significant new insight into the spatial extent of permafrost over larger areas (hundreds to thousands of square kilometers) than can be mapped using ground-based geophysical methods or through drilling. We compare several AEM datasets from different areas of interior Alaska, and explore the capacity of these data to infer geologic structure, permafrost extent, and related hydrologic processes. We also assess the impact of fires on permafrost by comparing data from different burn years within similar geological environments. Ultimately, interpretations rely on understanding the relationship between electrical resistivity measured by AEM surveys and the physical properties of interest such as geology, permafrost, and unfrozen water content in the subsurface. These relationships are often ambiguous and non-unique, so additional information is useful for reducing uncertainty. Shallow (upper ~1m) permafrost and soil characteristics identified from remotely sensed imagery and field observations help to constrain and aerially extend near-surface AEM interpretations, where correlations between the AEM and remote sensing data are identified using empirical multivariate analyses. Surface nuclear magnetic resonance (sNMR) measurements quantify the contribution of unfrozen water at depth to the AEM-derived electrical resistivity models at several locations within one survey area. AEM surveys fill a critical data gap in the subsurface characterization of permafrost environments and will be valuable in future mapping and monitoring programs in cold regions.

  13. Active airborne contamination control using electrophoresis

    SciTech Connect

    Veatch, B.D.

    1994-06-01

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

  14. Airborne laser communication technology and flight test

    NASA Astrophysics Data System (ADS)

    Meng, Li-xin; Zhang, Li-zhong; Li, Xiao-ming; Li, Ying-chao; Jiang, Hui-lin

    2015-11-01

    Reconnaissance aircraft is an important node of the space-air-ground integrated information network, on which equipped with a large number of high-resolution surveillance equipment, and need high speed communications equipment to transmit detected information in real time. Currently RF communication methods cannot meet the needs of communication bandwidth. Wireless laser communication has outstanding advantages high speed, high capacity, security, etc., is an important means to solve the high-speed information transmission of airborne platforms. In this paper, detailed analysis of how the system works, the system components, work processes, link power and the key technologies of airborne laser communication were discussed. On this basis, a prototype airborne laser communications was developed, and high-speed, long-distance communications tests were carried out between the two fixed-wing aircraft, and the airborne precision aiming, atmospheric laser communication impacts on laser communication were tested. The experiments ultimately realize that, the communication distance is 144km, the communication rate is 2.5Gbps. The Airborne laser communication experiments provide technical basis for the application of the conversion equipment.

  15. Airborne Gravimetry and Downward Continuation (Invited)

    NASA Astrophysics Data System (ADS)

    Jekeli, C.; Yang, H.; Kwon, J.

    2009-12-01

    Measuring the Earth’s gravity field using airborne instrumentation is fully operational and has been widely practiced for nearly three decades since its official debut in the early 1980s (S. Hammer: “Airborne Gravity is Here!”) coinciding with the precision kinematic positioning capability of GPS. Airborne gravimetry is undertaken for both efficient geophysical exploration purposes, as well as the determination of the regional geoid to aid in the modernization of height systems. Especially for the latter application, downward continuation of the data and combination with existing terrestrial gravimetry pose theoretical as well as practical challenges, which, on the other hand, create multiple processing possibilities. Downward continuation may be approached in various ways from the viewpoint of potential theory and the boundary-value problem to using gradients either estimated locally or computed from existing models. Logistical constraints imposed by the airborne survey, instrumental noise, and the intrinsic numerical instability of downward continuation all conspire to impact the final product in terms of achievable resolution and accuracy. In this paper, we review the theory of airborne gravimetry and the methodology of downward continuation, and provide a numerical comparison of possible schemes and their impact on geoid determination.

  16. Black pine (Pinus nigra) barks as biomonitors of airborne mercury pollution.

    PubMed

    Chiarantini, Laura; Rimondi, Valentina; Benvenuti, Marco; Beutel, Marc W; Costagliola, Pilario; Gonnelli, Cristina; Lattanzi, Pierfranco; Paolieri, Mario

    2016-11-01

    Tree barks are relevant interfaces between plants and the external environment, and can effectively retain airborne particles and elements at their surface. In this paper we have studied the distribution of mercury (Hg) in soils and in black pine (Pinus nigra) barks from the Mt. Amiata Hg district in southern Tuscany (Italy), where past Hg mining and present-day geothermal power plants affect local atmospheric Hg concentration, posing serious environmental concerns. Barks collected in heavily Hg-polluted areas of the district display the highest Hg concentration ever reported in literature (8.6mg/kg). In comparison, barks of the same species collected in local reference areas and near geothermal power plants show much lower (range 19-803μg/kg) concentrations; even lower concentrations are observed at a "blank" site near the city of Florence (5-98μg/kg). Results show a general decrease of Hg concentration from bark surface inwards, in accordance with a deposition of airborne Hg, with minor contribution from systemic uptake from soils. Preliminary results indicate that bark Hg concentrations are comparable with values reported for lichens in the same areas, suggesting that tree barks may represent an additional useful tool for biomonitoring of airborne Hg. PMID:27341111

  17. Airborne Bacteria in the Atmospheric Surface Layer: Temporal Distribution above a Grass Seed Field

    PubMed Central

    Lighthart, B.; Shaffer, B. T.

    1995-01-01

    Temporal airborne bacterial concentrations and meteorological conditions were measured above a grass seed field in the Willamette River Valley, near Corvallis, Oreg., in the summer of 1993. The concentration of airborne bacteria had a maximum of 1,368.5 CFU/m(sup3), with a coefficient of variation of 90.5% and a mean of 121.3 CFU/m(sup3). The lowest concentration of bacteria occurred during the predawn hours, with an average of 32.2 CFU/m(sup3), while sunrise and early evening hours had the highest averages (164.7 and 158.1 CFU/m(sup3), respectively). The concentrations of bacteria in the atmosphere varied greatly, with a maximum difference between two 2-min samples of 1,995 CFU/m(sup3). The concentrations of bacteria in the atmosphere could be divided into five time periods during the day that were thought to be related to the local diurnal sea breeze and Pacific Coast monsoon weather conditions as follows: (i) the nighttime minimum concentration, i.e., 2300 to 0600 h; (ii) the sunrise peak concentration, i.e., 0600 to 0800 h; (iii) the midday accumulating concentration, i.e., 0800 to 1515 h; (iv) the late-afternoon sea breeze trough concentration, i.e., 1515 to 1700 h; and (v) the evening decrease to the nighttime minimum concentration, i.e., 1700 to 2300 h. The sunrise peak concentration (period ii) is thought to be a relatively general phenomenon dependent on ground heating by the sun, while the afternoon trough concentration is thought to be a relatively local phenomenon dependent on the afternoon sea breeze. Meteorological conditions are thought to be an important regulating influence on airborne bacterial concentrations in the outdoor atmosphere in the Willamette River Valley. PMID:16534998

  18. Dynamics of airborne fungal populations in a large office building

    NASA Technical Reports Server (NTRS)

    Burge, H. A.; Pierson, D. L.; Groves, T. O.; Strawn, K. F.; Mishra, S. K.

    2000-01-01

    The increasing concern with bioaerosols in large office buildings prompted this prospective study of airborne fungal concentrations in a newly constructed building on the Gulf coast. We collected volumetric culture plate air samples on 14 occasions over the 18-month period immediately following building occupancy. On each sampling occasion, we collected duplicate samples from three sites on three floors of this six-story building, and an outdoor sample. Fungal concentrations indoors were consistently below those outdoors, and no sample clearly indicated fungal contamination in the building, although visible growth appeared in the ventilation system during the course of the study. We conclude that modern mechanically ventilated buildings prevent the intrusion of most of the outdoor fungal aerosol, and that even relatively extensive air sampling protocols may not sufficiently document the microbial status of buildings.

  19. Particle size of airborne mouse crude and defined allergens.

    PubMed

    Sakaguchi, M; Inouye, S; Miyazawa, H; Kamimura, H; Kimura, M; Yamazaki, S

    1989-05-01

    Laboratory animal allergy is a serious occupational diseases of many workers and scientists engaged in animal experimentation. Control measures depend upon characterization of allergens including airborne particles. This study measured the particle size of crude mouse urine and pelt aeroallergens generated in mouse housing rooms and compared them with mouse serum albumin, a defined major allergen. Allergens were detected by specific immunological methods. Most crude and defined allergens (74.5-86.4%) concentrated on a filter with a retention size greater than 7 microns. In distrubed air, allergen concentration increased 1.4 (albumin) to 5 (crude) fold and the proportion of small particles increased from 1.4% in calm air to 4.5% in distrubed air. This information on the generation and size distribution of aeroallergens will be important in the development of effective counter measures. PMID:2724924

  20. Modeling of estuarne chlorophyll a from an airborne scanner

    USGS Publications Warehouse

    Khorram, Siamak; Catts, Glenn P.; Cloern, James E.; Knight, Allen W.

    1987-01-01

    Near simultaneous collection of 34 surface water samples and airborne multispectral scanner data provided input for regression models developed to predict surface concentrations of estuarine chlorophyll a. Two wavelength ratios were employed in model development. The ratios werechosen to capitalize on the spectral characteristics of chlorophyll a, while minimizing atmospheric influences. Models were then applied to data previously acquired over the study area thre years earlier. Results are in the form of color-coded displays of predicted chlorophyll a concentrations and comparisons of the agreement among measured surface samples and predictions basedon coincident remotely sensed data. The influence of large variations in fresh-water inflow to the estuary are clearly apparent in the results. The synoptic view provided by remote sensing is another method of examining important estuarine dynamics difficult to observe from in situ sampling alone.

  1. Iridium enrichment in airborne particles from kilauea volcano: january 1983.

    PubMed

    Zoller, W H; Parrington, J R; Kotra, J M

    1983-12-01

    Airborne particulate matter from the January 1983 eruption of Kilauea volcano was inadvertently collected on air filters at Mauna Loa Observatory at a sampling station used to observe particles in global circulation. Analyses of affected samples revealed unusually large concentrations of selenium, arsenic, indium, gold, and sulfur, as expected for volcanic emissions. Strikingly large concentrations of iridium were also observed, the ratio of iridium to aluminum being 17,000 times its value in Hawaiian basalt. Since iridium enrichments have not previously been observed in volcanic emissions, the results for Kilauea suggest that it is part of an unusual volcanic system which may be fed by magma from the mantle. The iridium enrichment appears to be linked with the high fluorine content of the volcanic gases, which suggests that the iridium is released as a volatile IrF(6). PMID:17747384

  2. Airborne Particle Size Distribution Measurements at USDOE Fernald

    SciTech Connect

    Harley, N.H.; Chittaporn, P.; Heikkinen, M.; Medora, R.; Merrill, R.

    2003-03-27

    There are no long term measurements of the particle size distribution and concentration of airborne radionuclides at any USDOE facility except Fernald. Yet the determinant of lung dose is the particle size, determining the airway and lower lung deposition. Beginning in 2000, continuous (6 to 8 weeks) measurements of the aerosol particle size distribution have been made with a miniature sampler developed under EMSP. Radon gas decays to a chain of four short lived solid radionuclides that attach immediately to the resident atmospheric aerosol. These in turn decay to long lived polonium 210. Alpha emitting polonium is a tracer for any atmospheric aerosol. Six samplers at Fernald and four at QC sites in New Jersey show a difference in both polonium concentration and size distribution with the winter measurements being higher/larger than summer by almost a factor of two at all locations. EMSP USDOE Contract DE FG07 97ER62522.

  3. Seasonal Trends in Airborne Fungal Spores in Coastal California Ecosystems

    NASA Astrophysics Data System (ADS)

    Morfin, J.; Crandall, S. G.; Gilbert, G. S.

    2014-12-01

    Airborne fungal spores cause disease in plants and animals and may trigger respiratory illnesses in humans. In terrestrial systems, fungal sporulation, germination, and persistence are strongly regulated by local meteorological conditions. However, few studies investigate how microclimate affects the spatio-temporal dynamics of airborne spores. We measured fungal aerospora abundance and microclimate at varying spatial and time scales in coastal California in three habitat-types: coast redwood forest, mixed-evergreen forest, and maritime chaparral. We asked: 1) is there a difference in total airborne spore concentration between habitats, 2) when do we see peak spore counts, and 3) do spore densities correlate with microclimate conditions? Fungal spores were caught from the air with a volumetric vacuum air spore trap during the wet season (January - March) in 2013 and 2014, as well as monthly in 2014. Initial results suggest that mixed-evergreen forests exhibit the highest amounts of spore abundance in both years compared to the other habitats. This may be due to either a higher diversity of host plants in mixed-evergreen forests or a rich leaf litter layer that may harbor a greater abundance of saprotrophic fungi. Based on pilot data, we predict that temperature and to a lesser degree, relative humidity, will be important microclimate predictors for high spore densities. These data are important for understanding when and under what weather conditions we can expect to see high levels of fungal spores in the air; this can be useful information for managers who are interested in treating diseased plants with fungicides.

  4. Airborne space laser communication system and experiments

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  5. Profiles of Airborne Fungi in Buildings and Outdoor Environments in the United States

    PubMed Central

    Shelton, Brian G.; Kirkland, Kimberly H.; Flanders, W. Dana; Morris, George K.

    2002-01-01

    We examined 12,026 fungal air samples (9,619 indoor samples and 2,407 outdoor samples) from 1,717 buildings located across the United States; these samples were collected during indoor air quality investigations performed from 1996 to 1998. For all buildings, both indoor and outdoor air samples were collected with an Andersen N6 sampler. The culturable airborne fungal concentrations in indoor air were lower than those in outdoor air. The fungal levels were highest in the fall and summer and lowest in the winter and spring. Geographically, the highest fungal levels were found in the Southwest, Far West, and Southeast. The most common culturable airborne fungi, both indoors and outdoors and in all seasons and regions, were Cladosporium, Penicillium, nonsporulating fungi, and Aspergillus. Stachybotrys chartarum was identified in the indoor air in 6% of the buildings studied and in the outdoor air of 1% of the buildings studied. This study provides industrial hygienists, allergists, and other public health practitioners with comparative information on common culturable airborne fungi in the United States. This is the largest study of airborne indoor and outdoor fungal species and concentrations conducted with a standardized protocol to date. PMID:11916692

  6. Investigation of fluorine content in PM2.5 airborne particles of Istanbul, Turkey.

    PubMed

    Ozbek, Nil; Baltaci, Hakki; Baysal, Asli

    2016-07-01

    Fluorine determination in airborne samples is important due to its spread into the air from both natural and artificial sources. It can travel by wind over large distances before depositing on the Earth's surface. Its concentration in various matrices are limited and controlled by the regulations for causing health risks associated with environmental exposures. In this work, fluorine was determined in PM2.5 airborne samples by high-resolution continuum source electrothermal atomic absorption spectrometry. For these purpose, the PM2.5 airborne particulates were collected on quartz filters using high-volume samplers (500 L/min) in Istanbul (Turkey) for 96 h during January to June in 2 years. Then, instrumental and experimental parameters were optimized for the analyte in airborne samples. The validity of the method for the analyte was tested using standard reference material, and certified values were found in the limits of 95 % confidence level. The fluorine concentrations and meteorological conditions were compared statistically. PMID:27023803

  7. Verruculogen production in airborne and clinical isolates of Aspergillus fumigatus Fres.

    PubMed

    Kosalec, Ivan; Klarić, Maja Segvić; Pepeljnjak, Stjepan

    2005-12-01

    Among airborne aspergilli sampled in outdoor air of the Zagreb area (2002/2003), Aspergillus niger (v. Teigh.) and A. fumigatus (Fres.) were the most abundant species (20-30%), with low mean annual concentrations (0.21-1.04 CFU m-3). Higher concentrations of A. fumigatus were observed in autumn and winter (0.5-1.05 CFU m-3) than in spring and summer (0-0.4 CFU m-3). On the other hand, A. fumigatus was found to be the most frequent isolate from upper and/or lower respiratory tracts of imunocompromised patients in many studies. This species produces several mycotoxins, including the tremorgenic mycotoxin verruculogen that can be found in spores and during myceliar growth. Verruculogen production ability was tested on 30 airborne and 33 clinical isolates of A. fumigatus. In both groups, high percentage of verruculogen-producing strains was noticed (84% of airborne and 91% of clinical isolates). Verruculogen production was not significantly different in the groups of airborne isolates (0.34+/-0.16 mg mL-1), and clinical isolates (0.26+/-0.19 mg mL-1). PMID:16375825

  8. Effects of particle size and velocity on burial depth of airborne particles in glass fiber filters

    SciTech Connect

    Higby, D.P.

    1984-11-01

    Air sampling for particulate radioactive material involves collecting airborne particles on a filter and then determining the amount of radioactivity collected per unit volume of air drawn through the filter. The amount of radioactivity collected is frequently determined by directly measuring the radiation emitted from the particles collected on the filter. Counting losses caused by the particle becoming buried in the filter matrix may cause concentrations of airborne particulate radioactive materials to be underestimated by as much as 50%. Furthermore, the dose calculation for inhaled radionuclides will also be affected. The present study was designed to evaluate the extent to which particle size and sampling velocity influence burial depth in glass-fiber filters. Aerosols of high-fired /sup 239/PuO/sub 2/ were collected at various sampling velocities on glass-fiber filters. The fraction of alpha counts lost due to burial was determined as the ratio of activity detected by direct alpha count to the quantity determined by photon spectrometry. The results show that burial of airborne particles collected on glass-fiber filters appears to be a weak function of sampling velocity and particle size. Counting losses ranged from 0 to 25%. A correction that assumes losses of 10 to 15% would ensure that the concentration of airborne alpha-emitting radionuclides would not be underestimated when glass-fiber filters are used. 32 references, 21 figures, 11 tables.

  9. Approaches to detection of airborne biological agents

    NASA Astrophysics Data System (ADS)

    Chang, An-Cheng; Tabacco, Mary Beth

    2009-05-01

    Three approaches to detection of biological agents based on biological processes will be presented. The first example demonstrates the use of dendrimers to deliver a membrane-impermeable fluorescent dye into live bacteria, similar to viral infection and delivery of DNA/RNA into a bacterial cell. The second example mimics collection and capture of airborne biological particles by the respiratory mucosa through the use of a hygroscopic sensing membrane. The third example is based on the use of multiple fluorescent probes with diverse functionalities to detect airborne biological agents in a manner similar to the olfactory receptors in the nasal tract.

  10. Sandia Multispectral Airborne Lidar for UAV Deployment

    SciTech Connect

    Daniels, J.W.; Hargis,Jr. P.J.; Henson, T.D.; Jordan, J.D.; Lang, A.R.; Schmitt, R.L.

    1998-10-23

    Sandia National Laboratories has initiated the development of an airborne system for W laser remote sensing measurements. System applications include the detection of effluents associated with the proliferation of weapons of mass destruction and the detection of biological weapon aerosols. This paper discusses the status of the conceptual design development and plans for both the airborne payload (pointing and tracking, laser transmitter, and telescope receiver) and the Altus unmanned aerospace vehicle platform. Hardware design constraints necessary to maintain system weight, power, and volume limitations of the flight platform are identified.

  11. Correlation between predicted and observed levels of airborne tritium at Lawrence Livermore Laboratory site boundary

    SciTech Connect

    Lindeken, C.L.; Silver, W.J.; Toy, A.J.; White, J.H.

    1980-02-19

    At the Lawrence Livermore Laboratory, a computer code based on the Gaussian plume model is used to estimate radiation doses from routine or accidental release of airborne radioactive material. Routine releases of tritium have been used as a test of the overall uncertainty associated with these estimates. The ration of concentration to release rate at distances from the two principal release points to each of six site boundary sampling locations has been calcuated using local meteorological data. The concentration of airborne tritiated water vapor is continuously measured at the six sampling stations as part of the Laboratory's environmental monitoring program. Comparison of predicted with observed annual tritiated water concentrations in 1978 showed an average ratio of 2.6 with a range of from 0.97 to 5.8.

  12. Airborne Investigations and WRF -Model Calculations of the Bardarbunga-Holuhraun Eruption Plume

    NASA Astrophysics Data System (ADS)

    Weber, Konradin; Eliasson, Jonas; Arnason, Gylfi; Rognvaldsson, Olafur; Thorsteinsson, Throstur; Palsson, Thorgeir; Böhlke, Christoph; Fischer, Christian; Smith, Paul; Jones, Roderic; Tirpitz, Lukas; Platt, Ulrich

    2015-04-01

    The eruption in Holuhraun is the largest producer of lava and gas in Iceland since 1783. The Volcanic Ash Research (VAR) group organized an airborne measurement campaign including 10 flights, where emissions of SO2 and ash concentrations were measured at the source and at the far plume. The highest SO2 concentration at the source was nearly up to 100 mg/m3. This is an extremely high value, compared to other airborne campaigns and a contamination considered to cause serious illness by the Icelandic Directorate of Health. Volcanic ash consisted of very fine particles, but the concentration was low when compared to other recent eruptions. Measurements of the far plume showed that scavenging is very active. The dispersion was successfully modeled with the Weather Research and Foreast (WRF-chem) model and analysis using the model showed that a large amount of the sulphur was precipitated in the Icelandic highlands.

  13. NASA Airborne Lidar 1982-1984 Flights Data and Information

    Atmospheric Science Data Center

    2014-08-06

    NASA Airborne Lidar 1982-1984 Flights Data from the 1982 NASA Langley Airborne Lidar flights following the eruption of El Chichon ... continuing to January 1984. Transcribed from the following NASA Tech Reports: McCormick, M. P., and M. T. Osborn, Airborne lidar ...

  14. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  15. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  16. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  17. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  18. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  19. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  20. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  1. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  2. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  3. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  4. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  5. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  6. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  7. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  8. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  9. Elemental composition of airborne particulates and source identification - An extensive one year survey. [in Cleveland, OH

    NASA Technical Reports Server (NTRS)

    King, R. B.; Fordyce, J. S.; Antoine, A. C.; Leibecki, H. F.; Neustadter, H. E.; Sidik, S. M.

    1976-01-01

    Concentrations of 60 chemical elements in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1 year period during 1971 and 1972 (45 to 50 sampling days). Analytical methods used included instrumental neutron activation, emission spectroscopy, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, the analytical methods, the use of several analytical facilities, and samples with concentrations below the detection limits are evaluated in detail. The data are discussed in relation to other studies and source origins. The trace constituent concentrations as a function of wind direction are used to suggest a practical method for air pollution source identification.

  10. Potential Use of CW High Energy Laser on an Airborne Platform

    NASA Astrophysics Data System (ADS)

    Cook, Joung R.; Cusumano, Salvatore J.; Whiteley, Mathew R.

    2006-05-01

    Beamed energy propulsion (BEP) offers advanced and intellectually satisfying options to a class of space applications by using a high energy laser (HEL) as the prime power that is external to the system being propelled. Included in this class of applications are: launching satellites into orbit, space debris clearing, and orbital maneuvering, among others. Realistic applications or demonstrations of such BEP applications have been limited by the availability of HEL devices ever since the concept was first suggested by Arthur Kantrowitz in 1972. Development of the devices needed for BEP has been slow due to technology challenges and the significant non-recurring engineering costs. In general HEL systems of viable power levels have been exclusively the domain of military research and development. With the recent investment in the airborne platform laser systems, it may now be possible to capitalize on the military successes of such a system. The next decade may hold the possibility of transitioning defense HEL technology into BEP. The transitioning of military technology into civilian applications has occurred many times in the past, so speculation on available sources for BEP is not completely without merit. The concept of an airborne platform for BEP offers mobility and mitigates the coherence, reducing atmospheric turbulence. Operating at 12 kilometers (km), an airborne platform significantly reduces the beam path issues associated with ground to space. The trade-off is that the airborne platform disturbances are much greater and require more creative stabilization solutions than one sitting on "Terra Firma." The use of jitter reduction techniques may provide a profitable compromise for an airborne versus a ground-based system for BEP. This paper concentrates on the potential benefits from the use of an airborne platform for the BEP community.

  11. Airborne Detection and Tracking of Geologic Leakage Sites

    NASA Astrophysics Data System (ADS)

    Jacob, Jamey; Allamraju, Rakshit; Axelrod, Allan; Brown, Calvin; Chowdhary, Girish; Mitchell, Taylor

    2014-11-01

    Safe storage of CO2 to reduce greenhouse gas emissions without adversely affecting energy use or hindering economic growth requires development of monitoring technology that is capable of validating storage permanence while ensuring the integrity of sequestration operations. Soil gas monitoring has difficulty accurately distinguishing gas flux signals related to leakage from those associated with meteorologically driven changes of soil moisture and temperature. Integrated ground and airborne monitoring systems are being deployed capable of directly detecting CO2 concentration in storage sites. Two complimentary approaches to detecting leaks in the carbon sequestration fields are presented. The first approach focuses on reducing the requisite network communication for fusing individual Gaussian Process (GP) CO2 sensing models into a global GP CO2 model. The GP fusion approach learns how to optimally allocate the static and mobile sensors. The second approach leverages a hierarchical GP-Sigmoidal Gaussian Cox Process for airborne predictive mission planning to optimally reducing the entropy of the global CO2 model. Results from the approaches will be presented.

  12. 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

  13. Inversely tracking indoor airborne particles to locate their release sources

    NASA Astrophysics Data System (ADS)

    Zhang, Tengfei (Tim); Li, Hongzhu; Wang, Shugang

    2012-08-01

    Airborne particles can have numerous adverse effects on human health. Knowing the release locations of airborne particulate sources is helpful in minimizing pollutant exposure. This paper describes a proposal to locate indoor particulate sources by two inverse models: the quasi-reversibility (QR) model and the zone prescription of contaminant sources with the Lagrangian-reversibility (LR) model. The QR model reverses the time marching direction of the Eulerian governing equation and replaces the second-order diffusion term with a fourth-order stabilization term. The zone prescription LR model traces individual particulate motion in a Lagrangian reference frame after reversing the flow field. The particle trajectories are solved backward to the initial release once the conservative forces acting on particles are reversed. The tracked particles are proposed to be placed at the zone boundary of the largest concentration contour within the domain at a given time, which is provided as the initially known information. By connecting all particles at t = 0, a zone is formed that can prescribe the actual contaminant source. This study finds that both models can accurately locate particulate sources released instantaneously at a spot. The QR model performs slightly better than the LR model but is much more computationally demanding.

  14. Classification of airborne laser scanning data using JointBoost

    NASA Astrophysics Data System (ADS)

    Guo, Bo; Huang, Xianfeng; Zhang, Fan; Sohn, Gunho

    2015-02-01

    The demands for automatic point cloud classification have dramatically increased with the wide-spread use of airborne LiDAR. Existing research has mainly concentrated on a few dominant objects such as terrain, buildings and vegetation. In addition to those key objects, this paper proposes a supervised classification method to identify other types of objects including power-lines and pylons from point clouds using a JointBoost classifier. The parameters for the learning model are estimated with various features computed based on the geometry and echo information of a LiDAR point cloud. In order to overcome the shortcomings stemming from the inclusion of bare ground data before classification, the proposed classifier directly distinguishes terrain using a feature step-off count. Feature selection is conducted using JointBoost to evaluate feature correlations thus improving both classification accuracy and operational efficiency. In this paper, the contextual constraints for objects extracted by graph-cut segmentation are used to optimize the initial classification results obtained by the JointBoost classifier. Our experimental results show that the step-off count significantly contributes to classification. Seventeen effective features are selected for the initial classification results using the JointBoost classifier. Our experiments indicate that the proposed features and method are effective for classification of airborne LiDAR data from complex scenarios.

  15. Exposure to airborne microorganisms, dust and endotoxin during flax scutching on farms.

    PubMed

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

    2004-01-01

    Microbiological air sampling was performed on 5 flax farms located in eastern Poland. Air samples for determination of the concentrations of microorganisms, dust and endotoxin were collected in barns during machine scutching of flax stems by the farmers. The concentrations of mesophilic bacteria ranged from 203.5-698.8 x 10(3) cfu/m3, of Gram-negative bacteria from 27.2-123.4 x 10(3) cfu/m3, of thermophilic actinomycetes from 0.5-2.6 x 10(3) cfu/m3, and of fungi from 23.4-99.8 x 10(3) cfu/m3. The concentrations of total airborne microorganisms (bacteria + fungi) were within a range of 245.0-741.0 x 10(3) cfu/m3. The values of the respirable fraction of total airborne microflora on the examined farms were between 45.5-98.3%. Corynebacteria (irregular Gram-positive rods, mostly Corynebacterium spp.) were dominant at all sampling sites, forming 46.8-67.8% of the total airborne microflora. Among Gram-negative bacteria, the most numerous species was Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans), known to have strong endotoxic and allergenic properties. Among fungi, the allergenic species Alternaria alternata prevailed. Altogether, 25 species or genera of bacteria and 10 species or genera of fungi were identified in the farm air during flax scutching; of these, 11 and 6 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of airborne dust ranged within 43.7-648.1 mg/m3 (median 93.6 mg/m3), exceeding on all farms the Polish OEL value of 4 mg/m3. The concentrations of airborne endotoxin ranged within 16.9-172.1 microg/m3 (median 30.0 microg/m3), exceeding at all sampling sites the suggested OEL value of 0.2 microg/m). In conclusion, flax farmers performing machine scutching of flax could be exposed to large concentrations of airborne microorganisms, dust and endotoxin, posing a risk of work-related respiratory disease. PMID:15627342

  16. Airborne Satcom Terminal Research at NASA Glenn

    NASA Technical Reports Server (NTRS)

    Hoder, Doug; Zakrajsek, Robert

    2002-01-01

    NASA Glenn has constructed an airborne Ku-band satellite terminal, which provides wideband full-duplex ground-aircraft communications. The terminal makes use of novel electronically-steered phased array antennas and provides IP connectivity to and from the ground. The satcom terminal communications equipment may be easily changed whenever a new configuration is required, enhancing the terminal's versatility.

  17. Toolsets for Airborne Data Beta Release

    Atmospheric Science Data Center

    2014-09-17

    ... for Airborne Data (TAD), developed at the Atmospheric Science Data Center (ASDC) at NASA Langley Research Center (LaRC) to promote ... and Houston, and DC3 will be added shortly. Early next year we plan to add DISCOVER-AQ Colorado and SEAC4RS to the TAD database. We ...

  18. Mapping Waterhyacinth Infestations Using Airborne Hyperspectral Imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterhyacinth [Eichhornia crassipes (Mart.) Solms] is an exotic aquatic weed that often invades and clogs waterways in many tropical and subtropical regions of the world. The objective of this study was to evaluate airborne hyperspectral imagery and different image classification techniques for mapp...

  19. 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)

  20. Simulation system of airborne FLIR searcher

    NASA Astrophysics Data System (ADS)

    Sun, Kefeng; Li, Yu; Gao, Jiaobo; Wang, Jun; Wang, Jilong; Xie, Junhu; Ding, Na; Sun, Dandan

    2014-11-01

    Airborne Forward looking infra-red (FLIR) searcher simulation system can provide multi-mode simulated test environment that almost actual field environment, and can simulate integrated performance and external interface of airborne FLIR simulation system. Furthermore, the airborne FLIR searcher simulation system can support the algorithm optimization of image processing, and support the test and evaluation of electro-optical system, and also support the line test of software and evaluate the performance of the avionics system. The detailed design structure and information cross-linking relationship of each component are given in this paper. The simulation system is composed of the simulation center, the FLIR actuator, the FLIR emulator, and the display control terminal. The simulation center can generate the simulated target and aircraft flying data in the operation state of the airborne FLIR Searcher. The FLIR actuator can provide simulation scene. It can generate the infrared target and landform based scanning scene, response to the commands from simulation center and the FLIR actuator and operation control unit. The infrared image generated by the FLIR actuator can be processed by the FLIR emulator using PowerPC hardware framework and processing software based on VxWorks system. It can detect multi-target and output the DVI video and the multi-target detection information which corresponds to the working state of the FLIR searcher. Display control terminal can display the multi-target detection information in two-dimension situation format, and realize human-computer interaction function.